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Posted to commits@nuttx.apache.org by GitBox <gi...@apache.org> on 2022/01/06 19:08:10 UTC
[GitHub] [incubator-nuttx] acassis opened a new pull request #5187: esp32: Add PWM support using the LEDC peripheral @acassis
acassis opened a new pull request #5187:
URL: https://github.com/apache/incubator-nuttx/pull/5187
## Summary
This patch add support to PWM for ESP32
## Impact
User will be able to use PWM
## Testing
ESP32-Devkitc
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[GitHub] [incubator-nuttx] acassis commented on a change in pull request #5187: esp32: Add PWM support using the LEDC peripheral
Posted by GitBox <gi...@apache.org>.
acassis commented on a change in pull request #5187:
URL: https://github.com/apache/incubator-nuttx/pull/5187#discussion_r779845390
##########
File path: arch/xtensa/src/esp32/Kconfig
##########
@@ -324,9 +324,10 @@ config ESP32_I2S1
No yet implemented
config ESP32_LEDC
- bool "LED PWM (LEDC)"
+ bool "LEDC (PWM)"
default n
- depends on EXPERIMENTAL
+ select PWM
+ select ARCH_HAVE_PWM_MULTICHAN
---help---
No yet implemented
Review comment:
Hahaha, true! I forgot to remove the comment
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[GitHub] [incubator-nuttx] pkarashchenko commented on pull request #5187: esp32: Add PWM support using the LEDC peripheral
Posted by GitBox <gi...@apache.org>.
pkarashchenko commented on pull request #5187:
URL: https://github.com/apache/incubator-nuttx/pull/5187#issuecomment-1007995945
LGTM!
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[GitHub] [incubator-nuttx] pkarashchenko commented on a change in pull request #5187: esp32: Add PWM support using the LEDC peripheral
Posted by GitBox <gi...@apache.org>.
pkarashchenko commented on a change in pull request #5187:
URL: https://github.com/apache/incubator-nuttx/pull/5187#discussion_r780245216
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
+ " reload=%" PRIu32 "\n",
+ chan->num, chan->duty, (float)chan->duty / UINT16_MAX,
+ regval, priv->reload);
+
+ flags = enter_critical_section();
+
+ /* Reset config 0 & 1 registers */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF0_REG, 0);
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF1_REG, 0);
+
+ /* Set pulse phase 0 */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_HPOINT_REG, 0);
+
+ /* Duty register uses bits [18:4] */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_DUTY_REG, regval << 4);
+
+ /* Start GPIO output */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_SIG_OUT_EN_LSCH0);
+
+ /* Start Duty counter */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF1_REG, LEDC_DUTY_START_LSCH0);
+
+ /* Update duty and phase to hardware */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_PARA_UP_LSCH0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: pwm_setup
+ *
+ * Description:
+ * This method is called when the driver is opened. The lower half driver
+ * should configure and initialize the device so that it is ready for use.
+ * It should not, however, output pulses until the start method is called.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ ledc_enable_clk();
+
+ /* Setup channel GPIO pins */
+
+ for (int i = 0; i < priv->channels; i++)
+ {
+ pwminfo("channel%d --> pin%d\n", priv->chans[i].num,
+ priv->chans[i].pin);
+
+ esp32_configgpio(priv->chans[i].pin, OUTPUT | PULLUP);
+ esp32_gpio_matrix_out(priv->chans[i].pin,
+ LEDC_LS_SIG_OUT0_IDX + priv->chans[i].num,
+ 0, 0);
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_shutdown
+ *
+ * Description:
+ * This method is called when the driver is closed. The lower half driver
+ * stop pulsed output, free any resources, disable the timer hardware, and
+ * put the system into the lowest possible power usage state
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ /* Stop timer */
+
+ pwm_stop(dev);
+
+ /* Clear timer and channel configuration */
+
+ priv->frequency = 0;
+ priv->reload = 0;
+ for (int i = 0; i < channels; i++)
+ {
+ priv->chans[i].duty = 0;
+ }
+
+ ledc_disable_clk();
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_start
+ *
+ * Description:
+ * (Re-)initialize the timer resources and start the pulsed output
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * info - A reference to the characteristics of the pulsed output
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ pwminfo("PWM timer%d\n", priv->num);
Review comment:
@acassis do you plan to integrate this change?
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[GitHub] [incubator-nuttx] pkarashchenko commented on a change in pull request #5187: esp32: Add PWM support using the LEDC peripheral
Posted by GitBox <gi...@apache.org>.
pkarashchenko commented on a change in pull request #5187:
URL: https://github.com/apache/incubator-nuttx/pull/5187#discussion_r780245434
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
+ " reload=%" PRIu32 "\n",
+ chan->num, chan->duty, (float)chan->duty / UINT16_MAX,
+ regval, priv->reload);
+
+ flags = enter_critical_section();
+
+ /* Reset config 0 & 1 registers */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF0_REG, 0);
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF1_REG, 0);
+
+ /* Set pulse phase 0 */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_HPOINT_REG, 0);
+
+ /* Duty register uses bits [18:4] */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_DUTY_REG, regval << 4);
+
+ /* Start GPIO output */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_SIG_OUT_EN_LSCH0);
+
+ /* Start Duty counter */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF1_REG, LEDC_DUTY_START_LSCH0);
+
+ /* Update duty and phase to hardware */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_PARA_UP_LSCH0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: pwm_setup
+ *
+ * Description:
+ * This method is called when the driver is opened. The lower half driver
+ * should configure and initialize the device so that it is ready for use.
+ * It should not, however, output pulses until the start method is called.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ ledc_enable_clk();
+
+ /* Setup channel GPIO pins */
+
+ for (int i = 0; i < priv->channels; i++)
+ {
+ pwminfo("channel%d --> pin%d\n", priv->chans[i].num,
+ priv->chans[i].pin);
+
+ esp32_configgpio(priv->chans[i].pin, OUTPUT | PULLUP);
+ esp32_gpio_matrix_out(priv->chans[i].pin,
+ LEDC_LS_SIG_OUT0_IDX + priv->chans[i].num,
+ 0, 0);
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_shutdown
+ *
+ * Description:
+ * This method is called when the driver is closed. The lower half driver
+ * stop pulsed output, free any resources, disable the timer hardware, and
+ * put the system into the lowest possible power usage state
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ /* Stop timer */
+
+ pwm_stop(dev);
+
+ /* Clear timer and channel configuration */
+
+ priv->frequency = 0;
+ priv->reload = 0;
+ for (int i = 0; i < channels; i++)
+ {
+ priv->chans[i].duty = 0;
+ }
+
+ ledc_disable_clk();
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_start
+ *
+ * Description:
+ * (Re-)initialize the timer resources and start the pulsed output
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * info - A reference to the characteristics of the pulsed output
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ /* Update timer with given PWM timer frequency */
+
+ if (priv->frequency != info->frequency)
+ {
+ priv->frequency = info->frequency;
+ setup_timer(priv);
+ }
+
+ /* Update timer with given PWM channel duty */
+
+ for (int i = 0; i < channels; i++)
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ if (priv->chans[i].duty != info->channels[i].duty)
+#else
+ if (priv->chans[i].duty != info[i].duty)
+#endif
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ priv->chans[i].duty = info->channels[i].duty;
+#else
+ priv->chans[i].duty = info[i].duty;
+#endif
+ setup_channel(priv, i);
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_stop
+ *
+ * Description:
+ * Stop the pulsed output and reset the timer resources.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_stop(struct pwm_lowerhalf_s *dev)
+{
+ irqstate_t flags;
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
Review comment:
@acassis do you plan to integrate this change?
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[GitHub] [incubator-nuttx] pkarashchenko commented on pull request #5187: esp32: Add PWM support using the LEDC peripheral
Posted by GitBox <gi...@apache.org>.
pkarashchenko commented on pull request #5187:
URL: https://github.com/apache/incubator-nuttx/pull/5187#issuecomment-1007996610
> @pkarashchenko LGTM ?
I think it is fine to merge, but please address comments related to unsigned print specifier in the next commit
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[GitHub] [incubator-nuttx] pkarashchenko commented on a change in pull request #5187: esp32: Add PWM support using the LEDC peripheral
Posted by GitBox <gi...@apache.org>.
pkarashchenko commented on a change in pull request #5187:
URL: https://github.com/apache/incubator-nuttx/pull/5187#discussion_r779828273
##########
File path: arch/xtensa/src/esp32/Kconfig
##########
@@ -324,9 +324,10 @@ config ESP32_I2S1
No yet implemented
config ESP32_LEDC
- bool "LED PWM (LEDC)"
+ bool "LEDC (PWM)"
default n
- depends on EXPERIMENTAL
+ select PWM
+ select ARCH_HAVE_PWM_MULTICHAN
---help---
No yet implemented
Review comment:
Probably now it is implemented :)
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[GitHub] [incubator-nuttx] acassis commented on pull request #5187: esp32: Add PWM support using the LEDC peripheral
Posted by GitBox <gi...@apache.org>.
acassis commented on pull request #5187:
URL: https://github.com/apache/incubator-nuttx/pull/5187#issuecomment-1007987892
@pkarashchenko LGTM ?
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[GitHub] [incubator-nuttx] acassis commented on a change in pull request #5187: esp32: Add PWM support using the LEDC peripheral
Posted by GitBox <gi...@apache.org>.
acassis commented on a change in pull request #5187:
URL: https://github.com/apache/incubator-nuttx/pull/5187#discussion_r780233682
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,812 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
Review comment:
Unfortunately we cannot remove this defined(CONFIG_PWM_NCHANNELS), otherwise it will generate a warning when PWM_NCHANNELS is not used:
```
chip/esp32_ledc.c:52:5: warning: "CONFIG_PWM_NCHANNELS" is not defined, evaluates to 0 [-Wundef]
#if CONFIG_PWM_NCHANNELS > 1
^~~~~~~~~~~~~~~~~~~~
```
When "#if defined(CONFIG_PWM_NCHANNELS) && ..." is present the send part is not tested and the warning doesn't show up!
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,812 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
Review comment:
Unfortunately we cannot remove this defined(CONFIG_PWM_NCHANNELS), otherwise it will generate a warning when PWM_NCHANNELS is not used:
```
chip/esp32_ledc.c:52:5: warning: "CONFIG_PWM_NCHANNELS" is not defined, evaluates to 0 [-Wundef]
#if CONFIG_PWM_NCHANNELS > 1
^~~~~~~~~~~~~~~~~~~~
```
When "#if defined(CONFIG_PWM_NCHANNELS) && ..." is present the second part is not tested and the warning doesn't show up!
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[GitHub] [incubator-nuttx] pkarashchenko commented on a change in pull request #5187: esp32: Add PWM support using the LEDC peripheral
Posted by GitBox <gi...@apache.org>.
pkarashchenko commented on a change in pull request #5187:
URL: https://github.com/apache/incubator-nuttx/pull/5187#discussion_r779832401
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
Review comment:
```suggestion
if (g_clk_ref == 0)
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
Review comment:
```suggestion
if (g_clk_ref == 0)
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
+ " reload=%" PRIu32 "\n",
+ chan->num, chan->duty, (float)chan->duty / UINT16_MAX,
+ regval, priv->reload);
+
+ flags = enter_critical_section();
+
+ /* Reset config 0 & 1 registers */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF0_REG, 0);
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF1_REG, 0);
+
+ /* Set pulse phase 0 */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_HPOINT_REG, 0);
+
+ /* Duty register uses bits [18:4] */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_DUTY_REG, regval << 4);
+
+ /* Start GPIO output */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_SIG_OUT_EN_LSCH0);
+
+ /* Start Duty counter */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF1_REG, LEDC_DUTY_START_LSCH0);
+
+ /* Update duty and phase to hardware */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_PARA_UP_LSCH0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: pwm_setup
+ *
+ * Description:
+ * This method is called when the driver is opened. The lower half driver
+ * should configure and initialize the device so that it is ready for use.
+ * It should not, however, output pulses until the start method is called.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ ledc_enable_clk();
+
+ /* Setup channel GPIO pins */
+
+ for (int i = 0; i < priv->channels; i++)
+ {
+ pwminfo("channel%d --> pin%d\n", priv->chans[i].num,
+ priv->chans[i].pin);
+
+ esp32_configgpio(priv->chans[i].pin, OUTPUT | PULLUP);
+ esp32_gpio_matrix_out(priv->chans[i].pin,
+ LEDC_LS_SIG_OUT0_IDX + priv->chans[i].num,
+ 0, 0);
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_shutdown
+ *
+ * Description:
+ * This method is called when the driver is closed. The lower half driver
+ * stop pulsed output, free any resources, disable the timer hardware, and
+ * put the system into the lowest possible power usage state
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ /* Stop timer */
+
+ pwm_stop(dev);
+
+ /* Clear timer and channel configuration */
+
+ priv->frequency = 0;
+ priv->reload = 0;
+ for (int i = 0; i < channels; i++)
+ {
+ priv->chans[i].duty = 0;
+ }
+
+ ledc_disable_clk();
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_start
+ *
+ * Description:
+ * (Re-)initialize the timer resources and start the pulsed output
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * info - A reference to the characteristics of the pulsed output
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ /* Update timer with given PWM timer frequency */
+
+ if (priv->frequency != info->frequency)
+ {
+ priv->frequency = info->frequency;
+ setup_timer(priv);
+ }
+
+ /* Update timer with given PWM channel duty */
+
+ for (int i = 0; i < channels; i++)
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ if (priv->chans[i].duty != info->channels[i].duty)
+#else
+ if (priv->chans[i].duty != info[i].duty)
+#endif
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ priv->chans[i].duty = info->channels[i].duty;
+#else
+ priv->chans[i].duty = info[i].duty;
+#endif
+ setup_channel(priv, i);
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_stop
+ *
+ * Description:
+ * Stop the pulsed output and reset the timer resources.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_stop(struct pwm_lowerhalf_s *dev)
+{
+ irqstate_t flags;
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ flags = enter_critical_section();
+
+ /* Stop timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PAUSE);
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ leave_critical_section(flags);
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_ioctl
+ *
+ * Description:
+ * Lower-half logic may support platform-specific ioctl commands
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * cmd - The ioctl command
+ * arg - The argument accompanying the ioctl command
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg)
+{
+#ifdef CONFIG_DEBUG_PWM_INFO
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+#endif
+
+ return -ENOTTY;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: esp32_ledc_init
+ *
+ * Description:
+ * Initialize one LEDC timer for use with the upper_level PWM driver.
+ *
+ * Input Parameters:
+ * timer - A number identifying the timer use.
+ *
+ * Returned Value:
+ * On success, a pointer to the ESP32 LEDC lower half PWM driver is
+ * returned. NULL is returned on any failure.
+ *
+ ****************************************************************************/
+
+struct pwm_lowerhalf_s *esp32_ledc_init(int timer)
+{
+ struct esp32_ledc_s *lower = NULL;
+
+ pwminfo("TIM%u\n", timer);
+
+ switch (timer)
+ {
+#ifdef CONFIG_ESP32_LEDC_TIM0
+ case 0:
+ {
Review comment:
```suggestion
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
+ " reload=%" PRIu32 "\n",
+ chan->num, chan->duty, (float)chan->duty / UINT16_MAX,
+ regval, priv->reload);
+
+ flags = enter_critical_section();
+
+ /* Reset config 0 & 1 registers */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF0_REG, 0);
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF1_REG, 0);
+
+ /* Set pulse phase 0 */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_HPOINT_REG, 0);
+
+ /* Duty register uses bits [18:4] */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_DUTY_REG, regval << 4);
+
+ /* Start GPIO output */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_SIG_OUT_EN_LSCH0);
+
+ /* Start Duty counter */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF1_REG, LEDC_DUTY_START_LSCH0);
+
+ /* Update duty and phase to hardware */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_PARA_UP_LSCH0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: pwm_setup
+ *
+ * Description:
+ * This method is called when the driver is opened. The lower half driver
+ * should configure and initialize the device so that it is ready for use.
+ * It should not, however, output pulses until the start method is called.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ ledc_enable_clk();
+
+ /* Setup channel GPIO pins */
+
+ for (int i = 0; i < priv->channels; i++)
+ {
+ pwminfo("channel%d --> pin%d\n", priv->chans[i].num,
+ priv->chans[i].pin);
+
+ esp32_configgpio(priv->chans[i].pin, OUTPUT | PULLUP);
+ esp32_gpio_matrix_out(priv->chans[i].pin,
+ LEDC_LS_SIG_OUT0_IDX + priv->chans[i].num,
+ 0, 0);
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_shutdown
+ *
+ * Description:
+ * This method is called when the driver is closed. The lower half driver
+ * stop pulsed output, free any resources, disable the timer hardware, and
+ * put the system into the lowest possible power usage state
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ /* Stop timer */
+
+ pwm_stop(dev);
+
+ /* Clear timer and channel configuration */
+
+ priv->frequency = 0;
+ priv->reload = 0;
+ for (int i = 0; i < channels; i++)
+ {
+ priv->chans[i].duty = 0;
+ }
+
+ ledc_disable_clk();
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_start
+ *
+ * Description:
+ * (Re-)initialize the timer resources and start the pulsed output
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * info - A reference to the characteristics of the pulsed output
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ /* Update timer with given PWM timer frequency */
+
+ if (priv->frequency != info->frequency)
+ {
+ priv->frequency = info->frequency;
+ setup_timer(priv);
+ }
+
+ /* Update timer with given PWM channel duty */
+
+ for (int i = 0; i < channels; i++)
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ if (priv->chans[i].duty != info->channels[i].duty)
+#else
+ if (priv->chans[i].duty != info[i].duty)
+#endif
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ priv->chans[i].duty = info->channels[i].duty;
+#else
+ priv->chans[i].duty = info[i].duty;
+#endif
+ setup_channel(priv, i);
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_stop
+ *
+ * Description:
+ * Stop the pulsed output and reset the timer resources.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_stop(struct pwm_lowerhalf_s *dev)
+{
+ irqstate_t flags;
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ flags = enter_critical_section();
+
+ /* Stop timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PAUSE);
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ leave_critical_section(flags);
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_ioctl
+ *
+ * Description:
+ * Lower-half logic may support platform-specific ioctl commands
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * cmd - The ioctl command
+ * arg - The argument accompanying the ioctl command
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg)
+{
+#ifdef CONFIG_DEBUG_PWM_INFO
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+#endif
+
+ return -ENOTTY;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: esp32_ledc_init
+ *
+ * Description:
+ * Initialize one LEDC timer for use with the upper_level PWM driver.
+ *
+ * Input Parameters:
+ * timer - A number identifying the timer use.
+ *
+ * Returned Value:
+ * On success, a pointer to the ESP32 LEDC lower half PWM driver is
+ * returned. NULL is returned on any failure.
+ *
+ ****************************************************************************/
+
+struct pwm_lowerhalf_s *esp32_ledc_init(int timer)
+{
+ struct esp32_ledc_s *lower = NULL;
+
+ pwminfo("TIM%u\n", timer);
+
+ switch (timer)
+ {
+#ifdef CONFIG_ESP32_LEDC_TIM0
+ case 0:
+ {
+ lower = &g_pwm0dev;
+ break;
+ }
+#endif
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+ case 1:
+ {
+ lower = &g_pwm1dev;
+ break;
+ }
Review comment:
```suggestion
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
+ " reload=%" PRIu32 "\n",
+ chan->num, chan->duty, (float)chan->duty / UINT16_MAX,
+ regval, priv->reload);
+
+ flags = enter_critical_section();
+
+ /* Reset config 0 & 1 registers */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF0_REG, 0);
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF1_REG, 0);
+
+ /* Set pulse phase 0 */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_HPOINT_REG, 0);
+
+ /* Duty register uses bits [18:4] */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_DUTY_REG, regval << 4);
+
+ /* Start GPIO output */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_SIG_OUT_EN_LSCH0);
+
+ /* Start Duty counter */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF1_REG, LEDC_DUTY_START_LSCH0);
+
+ /* Update duty and phase to hardware */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_PARA_UP_LSCH0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: pwm_setup
+ *
+ * Description:
+ * This method is called when the driver is opened. The lower half driver
+ * should configure and initialize the device so that it is ready for use.
+ * It should not, however, output pulses until the start method is called.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ ledc_enable_clk();
+
+ /* Setup channel GPIO pins */
+
+ for (int i = 0; i < priv->channels; i++)
+ {
+ pwminfo("channel%d --> pin%d\n", priv->chans[i].num,
+ priv->chans[i].pin);
+
+ esp32_configgpio(priv->chans[i].pin, OUTPUT | PULLUP);
+ esp32_gpio_matrix_out(priv->chans[i].pin,
+ LEDC_LS_SIG_OUT0_IDX + priv->chans[i].num,
+ 0, 0);
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_shutdown
+ *
+ * Description:
+ * This method is called when the driver is closed. The lower half driver
+ * stop pulsed output, free any resources, disable the timer hardware, and
+ * put the system into the lowest possible power usage state
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ /* Stop timer */
+
+ pwm_stop(dev);
+
+ /* Clear timer and channel configuration */
+
+ priv->frequency = 0;
+ priv->reload = 0;
+ for (int i = 0; i < channels; i++)
+ {
+ priv->chans[i].duty = 0;
+ }
+
+ ledc_disable_clk();
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_start
+ *
+ * Description:
+ * (Re-)initialize the timer resources and start the pulsed output
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * info - A reference to the characteristics of the pulsed output
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ /* Update timer with given PWM timer frequency */
+
+ if (priv->frequency != info->frequency)
+ {
+ priv->frequency = info->frequency;
+ setup_timer(priv);
+ }
+
+ /* Update timer with given PWM channel duty */
+
+ for (int i = 0; i < channels; i++)
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ if (priv->chans[i].duty != info->channels[i].duty)
+#else
+ if (priv->chans[i].duty != info[i].duty)
+#endif
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ priv->chans[i].duty = info->channels[i].duty;
+#else
+ priv->chans[i].duty = info[i].duty;
+#endif
+ setup_channel(priv, i);
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_stop
+ *
+ * Description:
+ * Stop the pulsed output and reset the timer resources.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_stop(struct pwm_lowerhalf_s *dev)
+{
+ irqstate_t flags;
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ flags = enter_critical_section();
+
+ /* Stop timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PAUSE);
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ leave_critical_section(flags);
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_ioctl
+ *
+ * Description:
+ * Lower-half logic may support platform-specific ioctl commands
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * cmd - The ioctl command
+ * arg - The argument accompanying the ioctl command
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg)
+{
+#ifdef CONFIG_DEBUG_PWM_INFO
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+#endif
+
+ return -ENOTTY;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: esp32_ledc_init
+ *
+ * Description:
+ * Initialize one LEDC timer for use with the upper_level PWM driver.
+ *
+ * Input Parameters:
+ * timer - A number identifying the timer use.
+ *
+ * Returned Value:
+ * On success, a pointer to the ESP32 LEDC lower half PWM driver is
+ * returned. NULL is returned on any failure.
+ *
+ ****************************************************************************/
+
+struct pwm_lowerhalf_s *esp32_ledc_init(int timer)
+{
+ struct esp32_ledc_s *lower = NULL;
+
+ pwminfo("TIM%u\n", timer);
+
+ switch (timer)
+ {
+#ifdef CONFIG_ESP32_LEDC_TIM0
+ case 0:
+ {
+ lower = &g_pwm0dev;
+ break;
+ }
+#endif
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+ case 1:
+ {
+ lower = &g_pwm1dev;
+ break;
+ }
+#endif
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+ case 2:
+ {
Review comment:
```suggestion
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
+ " reload=%" PRIu32 "\n",
+ chan->num, chan->duty, (float)chan->duty / UINT16_MAX,
+ regval, priv->reload);
+
+ flags = enter_critical_section();
+
+ /* Reset config 0 & 1 registers */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF0_REG, 0);
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF1_REG, 0);
+
+ /* Set pulse phase 0 */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_HPOINT_REG, 0);
+
+ /* Duty register uses bits [18:4] */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_DUTY_REG, regval << 4);
+
+ /* Start GPIO output */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_SIG_OUT_EN_LSCH0);
+
+ /* Start Duty counter */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF1_REG, LEDC_DUTY_START_LSCH0);
+
+ /* Update duty and phase to hardware */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_PARA_UP_LSCH0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: pwm_setup
+ *
+ * Description:
+ * This method is called when the driver is opened. The lower half driver
+ * should configure and initialize the device so that it is ready for use.
+ * It should not, however, output pulses until the start method is called.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ ledc_enable_clk();
+
+ /* Setup channel GPIO pins */
+
+ for (int i = 0; i < priv->channels; i++)
+ {
+ pwminfo("channel%d --> pin%d\n", priv->chans[i].num,
+ priv->chans[i].pin);
+
+ esp32_configgpio(priv->chans[i].pin, OUTPUT | PULLUP);
+ esp32_gpio_matrix_out(priv->chans[i].pin,
+ LEDC_LS_SIG_OUT0_IDX + priv->chans[i].num,
+ 0, 0);
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_shutdown
+ *
+ * Description:
+ * This method is called when the driver is closed. The lower half driver
+ * stop pulsed output, free any resources, disable the timer hardware, and
+ * put the system into the lowest possible power usage state
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ /* Stop timer */
+
+ pwm_stop(dev);
+
+ /* Clear timer and channel configuration */
+
+ priv->frequency = 0;
+ priv->reload = 0;
+ for (int i = 0; i < channels; i++)
+ {
+ priv->chans[i].duty = 0;
+ }
+
+ ledc_disable_clk();
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_start
+ *
+ * Description:
+ * (Re-)initialize the timer resources and start the pulsed output
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * info - A reference to the characteristics of the pulsed output
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ /* Update timer with given PWM timer frequency */
+
+ if (priv->frequency != info->frequency)
+ {
+ priv->frequency = info->frequency;
+ setup_timer(priv);
+ }
+
+ /* Update timer with given PWM channel duty */
+
+ for (int i = 0; i < channels; i++)
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ if (priv->chans[i].duty != info->channels[i].duty)
+#else
+ if (priv->chans[i].duty != info[i].duty)
+#endif
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ priv->chans[i].duty = info->channels[i].duty;
+#else
+ priv->chans[i].duty = info[i].duty;
+#endif
+ setup_channel(priv, i);
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_stop
+ *
+ * Description:
+ * Stop the pulsed output and reset the timer resources.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_stop(struct pwm_lowerhalf_s *dev)
+{
+ irqstate_t flags;
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ flags = enter_critical_section();
+
+ /* Stop timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PAUSE);
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ leave_critical_section(flags);
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_ioctl
+ *
+ * Description:
+ * Lower-half logic may support platform-specific ioctl commands
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * cmd - The ioctl command
+ * arg - The argument accompanying the ioctl command
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg)
+{
+#ifdef CONFIG_DEBUG_PWM_INFO
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+#endif
+
+ return -ENOTTY;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: esp32_ledc_init
+ *
+ * Description:
+ * Initialize one LEDC timer for use with the upper_level PWM driver.
+ *
+ * Input Parameters:
+ * timer - A number identifying the timer use.
+ *
+ * Returned Value:
+ * On success, a pointer to the ESP32 LEDC lower half PWM driver is
+ * returned. NULL is returned on any failure.
+ *
+ ****************************************************************************/
+
+struct pwm_lowerhalf_s *esp32_ledc_init(int timer)
+{
+ struct esp32_ledc_s *lower = NULL;
+
+ pwminfo("TIM%u\n", timer);
+
+ switch (timer)
+ {
+#ifdef CONFIG_ESP32_LEDC_TIM0
+ case 0:
+ {
+ lower = &g_pwm0dev;
+ break;
+ }
+#endif
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+ case 1:
+ {
Review comment:
```suggestion
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
+ " reload=%" PRIu32 "\n",
+ chan->num, chan->duty, (float)chan->duty / UINT16_MAX,
+ regval, priv->reload);
+
+ flags = enter_critical_section();
+
+ /* Reset config 0 & 1 registers */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF0_REG, 0);
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF1_REG, 0);
+
+ /* Set pulse phase 0 */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_HPOINT_REG, 0);
+
+ /* Duty register uses bits [18:4] */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_DUTY_REG, regval << 4);
+
+ /* Start GPIO output */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_SIG_OUT_EN_LSCH0);
+
+ /* Start Duty counter */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF1_REG, LEDC_DUTY_START_LSCH0);
+
+ /* Update duty and phase to hardware */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_PARA_UP_LSCH0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: pwm_setup
+ *
+ * Description:
+ * This method is called when the driver is opened. The lower half driver
+ * should configure and initialize the device so that it is ready for use.
+ * It should not, however, output pulses until the start method is called.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ ledc_enable_clk();
+
+ /* Setup channel GPIO pins */
+
+ for (int i = 0; i < priv->channels; i++)
+ {
+ pwminfo("channel%d --> pin%d\n", priv->chans[i].num,
+ priv->chans[i].pin);
+
+ esp32_configgpio(priv->chans[i].pin, OUTPUT | PULLUP);
+ esp32_gpio_matrix_out(priv->chans[i].pin,
+ LEDC_LS_SIG_OUT0_IDX + priv->chans[i].num,
+ 0, 0);
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_shutdown
+ *
+ * Description:
+ * This method is called when the driver is closed. The lower half driver
+ * stop pulsed output, free any resources, disable the timer hardware, and
+ * put the system into the lowest possible power usage state
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ /* Stop timer */
+
+ pwm_stop(dev);
+
+ /* Clear timer and channel configuration */
+
+ priv->frequency = 0;
+ priv->reload = 0;
+ for (int i = 0; i < channels; i++)
+ {
+ priv->chans[i].duty = 0;
+ }
+
+ ledc_disable_clk();
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_start
+ *
+ * Description:
+ * (Re-)initialize the timer resources and start the pulsed output
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * info - A reference to the characteristics of the pulsed output
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ /* Update timer with given PWM timer frequency */
+
+ if (priv->frequency != info->frequency)
+ {
+ priv->frequency = info->frequency;
+ setup_timer(priv);
+ }
+
+ /* Update timer with given PWM channel duty */
+
+ for (int i = 0; i < channels; i++)
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ if (priv->chans[i].duty != info->channels[i].duty)
+#else
+ if (priv->chans[i].duty != info[i].duty)
+#endif
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ priv->chans[i].duty = info->channels[i].duty;
+#else
+ priv->chans[i].duty = info[i].duty;
+#endif
+ setup_channel(priv, i);
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_stop
+ *
+ * Description:
+ * Stop the pulsed output and reset the timer resources.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_stop(struct pwm_lowerhalf_s *dev)
+{
+ irqstate_t flags;
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ flags = enter_critical_section();
+
+ /* Stop timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PAUSE);
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ leave_critical_section(flags);
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_ioctl
+ *
+ * Description:
+ * Lower-half logic may support platform-specific ioctl commands
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * cmd - The ioctl command
+ * arg - The argument accompanying the ioctl command
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg)
+{
+#ifdef CONFIG_DEBUG_PWM_INFO
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+#endif
+
+ return -ENOTTY;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: esp32_ledc_init
+ *
+ * Description:
+ * Initialize one LEDC timer for use with the upper_level PWM driver.
+ *
+ * Input Parameters:
+ * timer - A number identifying the timer use.
+ *
+ * Returned Value:
+ * On success, a pointer to the ESP32 LEDC lower half PWM driver is
+ * returned. NULL is returned on any failure.
+ *
+ ****************************************************************************/
+
+struct pwm_lowerhalf_s *esp32_ledc_init(int timer)
+{
+ struct esp32_ledc_s *lower = NULL;
+
+ pwminfo("TIM%u\n", timer);
+
+ switch (timer)
+ {
+#ifdef CONFIG_ESP32_LEDC_TIM0
+ case 0:
+ {
+ lower = &g_pwm0dev;
+ break;
+ }
+#endif
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+ case 1:
+ {
+ lower = &g_pwm1dev;
+ break;
+ }
+#endif
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+ case 2:
+ {
+ lower = &g_pwm2dev;
+ break;
+ }
Review comment:
```suggestion
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
+ " reload=%" PRIu32 "\n",
+ chan->num, chan->duty, (float)chan->duty / UINT16_MAX,
+ regval, priv->reload);
+
+ flags = enter_critical_section();
+
+ /* Reset config 0 & 1 registers */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF0_REG, 0);
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF1_REG, 0);
+
+ /* Set pulse phase 0 */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_HPOINT_REG, 0);
+
+ /* Duty register uses bits [18:4] */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_DUTY_REG, regval << 4);
+
+ /* Start GPIO output */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_SIG_OUT_EN_LSCH0);
+
+ /* Start Duty counter */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF1_REG, LEDC_DUTY_START_LSCH0);
+
+ /* Update duty and phase to hardware */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_PARA_UP_LSCH0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: pwm_setup
+ *
+ * Description:
+ * This method is called when the driver is opened. The lower half driver
+ * should configure and initialize the device so that it is ready for use.
+ * It should not, however, output pulses until the start method is called.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ ledc_enable_clk();
+
+ /* Setup channel GPIO pins */
+
+ for (int i = 0; i < priv->channels; i++)
+ {
+ pwminfo("channel%d --> pin%d\n", priv->chans[i].num,
+ priv->chans[i].pin);
+
+ esp32_configgpio(priv->chans[i].pin, OUTPUT | PULLUP);
+ esp32_gpio_matrix_out(priv->chans[i].pin,
+ LEDC_LS_SIG_OUT0_IDX + priv->chans[i].num,
+ 0, 0);
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_shutdown
+ *
+ * Description:
+ * This method is called when the driver is closed. The lower half driver
+ * stop pulsed output, free any resources, disable the timer hardware, and
+ * put the system into the lowest possible power usage state
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ /* Stop timer */
+
+ pwm_stop(dev);
+
+ /* Clear timer and channel configuration */
+
+ priv->frequency = 0;
+ priv->reload = 0;
+ for (int i = 0; i < channels; i++)
+ {
+ priv->chans[i].duty = 0;
+ }
+
+ ledc_disable_clk();
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_start
+ *
+ * Description:
+ * (Re-)initialize the timer resources and start the pulsed output
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * info - A reference to the characteristics of the pulsed output
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ /* Update timer with given PWM timer frequency */
+
+ if (priv->frequency != info->frequency)
+ {
+ priv->frequency = info->frequency;
+ setup_timer(priv);
+ }
+
+ /* Update timer with given PWM channel duty */
+
+ for (int i = 0; i < channels; i++)
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ if (priv->chans[i].duty != info->channels[i].duty)
+#else
+ if (priv->chans[i].duty != info[i].duty)
+#endif
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ priv->chans[i].duty = info->channels[i].duty;
+#else
+ priv->chans[i].duty = info[i].duty;
+#endif
+ setup_channel(priv, i);
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_stop
+ *
+ * Description:
+ * Stop the pulsed output and reset the timer resources.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_stop(struct pwm_lowerhalf_s *dev)
+{
+ irqstate_t flags;
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
Review comment:
```suggestion
pwminfo("PWM timer%u\n", priv->num);
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
+ " reload=%" PRIu32 "\n",
+ chan->num, chan->duty, (float)chan->duty / UINT16_MAX,
+ regval, priv->reload);
+
+ flags = enter_critical_section();
+
+ /* Reset config 0 & 1 registers */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF0_REG, 0);
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF1_REG, 0);
+
+ /* Set pulse phase 0 */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_HPOINT_REG, 0);
+
+ /* Duty register uses bits [18:4] */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_DUTY_REG, regval << 4);
+
+ /* Start GPIO output */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_SIG_OUT_EN_LSCH0);
+
+ /* Start Duty counter */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF1_REG, LEDC_DUTY_START_LSCH0);
+
+ /* Update duty and phase to hardware */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_PARA_UP_LSCH0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: pwm_setup
+ *
+ * Description:
+ * This method is called when the driver is opened. The lower half driver
+ * should configure and initialize the device so that it is ready for use.
+ * It should not, however, output pulses until the start method is called.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
Review comment:
```suggestion
pwminfo("PWM timer%u\n", priv->num);
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
Review comment:
```suggestion
pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
+ " reload=%" PRIu32 "\n",
+ chan->num, chan->duty, (float)chan->duty / UINT16_MAX,
+ regval, priv->reload);
+
+ flags = enter_critical_section();
+
+ /* Reset config 0 & 1 registers */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF0_REG, 0);
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF1_REG, 0);
+
+ /* Set pulse phase 0 */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_HPOINT_REG, 0);
+
+ /* Duty register uses bits [18:4] */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_DUTY_REG, regval << 4);
+
+ /* Start GPIO output */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_SIG_OUT_EN_LSCH0);
+
+ /* Start Duty counter */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF1_REG, LEDC_DUTY_START_LSCH0);
+
+ /* Update duty and phase to hardware */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_PARA_UP_LSCH0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: pwm_setup
+ *
+ * Description:
+ * This method is called when the driver is opened. The lower half driver
+ * should configure and initialize the device so that it is ready for use.
+ * It should not, however, output pulses until the start method is called.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ ledc_enable_clk();
+
+ /* Setup channel GPIO pins */
+
+ for (int i = 0; i < priv->channels; i++)
+ {
+ pwminfo("channel%d --> pin%d\n", priv->chans[i].num,
+ priv->chans[i].pin);
+
+ esp32_configgpio(priv->chans[i].pin, OUTPUT | PULLUP);
+ esp32_gpio_matrix_out(priv->chans[i].pin,
+ LEDC_LS_SIG_OUT0_IDX + priv->chans[i].num,
+ 0, 0);
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_shutdown
+ *
+ * Description:
+ * This method is called when the driver is closed. The lower half driver
+ * stop pulsed output, free any resources, disable the timer hardware, and
+ * put the system into the lowest possible power usage state
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ /* Stop timer */
+
+ pwm_stop(dev);
+
+ /* Clear timer and channel configuration */
+
+ priv->frequency = 0;
+ priv->reload = 0;
+ for (int i = 0; i < channels; i++)
+ {
+ priv->chans[i].duty = 0;
+ }
+
+ ledc_disable_clk();
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_start
+ *
+ * Description:
+ * (Re-)initialize the timer resources and start the pulsed output
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * info - A reference to the characteristics of the pulsed output
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ /* Update timer with given PWM timer frequency */
+
+ if (priv->frequency != info->frequency)
+ {
+ priv->frequency = info->frequency;
+ setup_timer(priv);
+ }
+
+ /* Update timer with given PWM channel duty */
+
+ for (int i = 0; i < channels; i++)
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ if (priv->chans[i].duty != info->channels[i].duty)
+#else
+ if (priv->chans[i].duty != info[i].duty)
+#endif
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ priv->chans[i].duty = info->channels[i].duty;
+#else
+ priv->chans[i].duty = info[i].duty;
+#endif
+ setup_channel(priv, i);
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_stop
+ *
+ * Description:
+ * Stop the pulsed output and reset the timer resources.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_stop(struct pwm_lowerhalf_s *dev)
+{
+ irqstate_t flags;
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ flags = enter_critical_section();
+
+ /* Stop timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PAUSE);
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ leave_critical_section(flags);
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_ioctl
+ *
+ * Description:
+ * Lower-half logic may support platform-specific ioctl commands
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * cmd - The ioctl command
+ * arg - The argument accompanying the ioctl command
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg)
+{
+#ifdef CONFIG_DEBUG_PWM_INFO
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+#endif
+
+ return -ENOTTY;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: esp32_ledc_init
+ *
+ * Description:
+ * Initialize one LEDC timer for use with the upper_level PWM driver.
+ *
+ * Input Parameters:
+ * timer - A number identifying the timer use.
+ *
+ * Returned Value:
+ * On success, a pointer to the ESP32 LEDC lower half PWM driver is
+ * returned. NULL is returned on any failure.
+ *
+ ****************************************************************************/
+
+struct pwm_lowerhalf_s *esp32_ledc_init(int timer)
+{
+ struct esp32_ledc_s *lower = NULL;
+
+ pwminfo("TIM%u\n", timer);
+
+ switch (timer)
+ {
+#ifdef CONFIG_ESP32_LEDC_TIM0
+ case 0:
+ {
+ lower = &g_pwm0dev;
+ break;
+ }
+#endif
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+ case 1:
+ {
+ lower = &g_pwm1dev;
+ break;
+ }
+#endif
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+ case 2:
+ {
+ lower = &g_pwm2dev;
+ break;
+ }
+#endif
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+ case 3:
+ {
Review comment:
```suggestion
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
Review comment:
```suggestion
pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%"
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
+ " reload=%" PRIu32 "\n",
+ chan->num, chan->duty, (float)chan->duty / UINT16_MAX,
+ regval, priv->reload);
+
+ flags = enter_critical_section();
+
+ /* Reset config 0 & 1 registers */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF0_REG, 0);
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF1_REG, 0);
+
+ /* Set pulse phase 0 */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_HPOINT_REG, 0);
+
+ /* Duty register uses bits [18:4] */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_DUTY_REG, regval << 4);
+
+ /* Start GPIO output */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_SIG_OUT_EN_LSCH0);
+
+ /* Start Duty counter */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF1_REG, LEDC_DUTY_START_LSCH0);
+
+ /* Update duty and phase to hardware */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_PARA_UP_LSCH0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: pwm_setup
+ *
+ * Description:
+ * This method is called when the driver is opened. The lower half driver
+ * should configure and initialize the device so that it is ready for use.
+ * It should not, however, output pulses until the start method is called.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ ledc_enable_clk();
+
+ /* Setup channel GPIO pins */
+
+ for (int i = 0; i < priv->channels; i++)
+ {
+ pwminfo("channel%d --> pin%d\n", priv->chans[i].num,
+ priv->chans[i].pin);
+
+ esp32_configgpio(priv->chans[i].pin, OUTPUT | PULLUP);
+ esp32_gpio_matrix_out(priv->chans[i].pin,
+ LEDC_LS_SIG_OUT0_IDX + priv->chans[i].num,
+ 0, 0);
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_shutdown
+ *
+ * Description:
+ * This method is called when the driver is closed. The lower half driver
+ * stop pulsed output, free any resources, disable the timer hardware, and
+ * put the system into the lowest possible power usage state
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ /* Stop timer */
+
+ pwm_stop(dev);
+
+ /* Clear timer and channel configuration */
+
+ priv->frequency = 0;
+ priv->reload = 0;
+ for (int i = 0; i < channels; i++)
+ {
+ priv->chans[i].duty = 0;
+ }
+
+ ledc_disable_clk();
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_start
+ *
+ * Description:
+ * (Re-)initialize the timer resources and start the pulsed output
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * info - A reference to the characteristics of the pulsed output
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ /* Update timer with given PWM timer frequency */
+
+ if (priv->frequency != info->frequency)
+ {
+ priv->frequency = info->frequency;
+ setup_timer(priv);
+ }
+
+ /* Update timer with given PWM channel duty */
+
+ for (int i = 0; i < channels; i++)
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ if (priv->chans[i].duty != info->channels[i].duty)
+#else
+ if (priv->chans[i].duty != info[i].duty)
+#endif
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ priv->chans[i].duty = info->channels[i].duty;
+#else
+ priv->chans[i].duty = info[i].duty;
+#endif
+ setup_channel(priv, i);
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_stop
+ *
+ * Description:
+ * Stop the pulsed output and reset the timer resources.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_stop(struct pwm_lowerhalf_s *dev)
+{
+ irqstate_t flags;
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ flags = enter_critical_section();
+
+ /* Stop timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PAUSE);
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ leave_critical_section(flags);
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_ioctl
+ *
+ * Description:
+ * Lower-half logic may support platform-specific ioctl commands
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * cmd - The ioctl command
+ * arg - The argument accompanying the ioctl command
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg)
+{
+#ifdef CONFIG_DEBUG_PWM_INFO
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+#endif
+
+ return -ENOTTY;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: esp32_ledc_init
+ *
+ * Description:
+ * Initialize one LEDC timer for use with the upper_level PWM driver.
+ *
+ * Input Parameters:
+ * timer - A number identifying the timer use.
+ *
+ * Returned Value:
+ * On success, a pointer to the ESP32 LEDC lower half PWM driver is
+ * returned. NULL is returned on any failure.
+ *
+ ****************************************************************************/
+
+struct pwm_lowerhalf_s *esp32_ledc_init(int timer)
+{
+ struct esp32_ledc_s *lower = NULL;
+
+ pwminfo("TIM%u\n", timer);
+
+ switch (timer)
+ {
+#ifdef CONFIG_ESP32_LEDC_TIM0
+ case 0:
+ {
+ lower = &g_pwm0dev;
+ break;
+ }
+#endif
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+ case 1:
+ {
+ lower = &g_pwm1dev;
+ break;
+ }
+#endif
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+ case 2:
+ {
+ lower = &g_pwm2dev;
+ break;
+ }
+#endif
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+ case 3:
+ {
+ lower = &g_pwm3dev;
+ break;
+ }
Review comment:
```suggestion
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
+ " reload=%" PRIu32 "\n",
+ chan->num, chan->duty, (float)chan->duty / UINT16_MAX,
+ regval, priv->reload);
+
+ flags = enter_critical_section();
+
+ /* Reset config 0 & 1 registers */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF0_REG, 0);
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF1_REG, 0);
+
+ /* Set pulse phase 0 */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_HPOINT_REG, 0);
+
+ /* Duty register uses bits [18:4] */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_DUTY_REG, regval << 4);
+
+ /* Start GPIO output */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_SIG_OUT_EN_LSCH0);
+
+ /* Start Duty counter */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF1_REG, LEDC_DUTY_START_LSCH0);
+
+ /* Update duty and phase to hardware */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_PARA_UP_LSCH0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: pwm_setup
+ *
+ * Description:
+ * This method is called when the driver is opened. The lower half driver
+ * should configure and initialize the device so that it is ready for use.
+ * It should not, however, output pulses until the start method is called.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ ledc_enable_clk();
+
+ /* Setup channel GPIO pins */
+
+ for (int i = 0; i < priv->channels; i++)
+ {
+ pwminfo("channel%d --> pin%d\n", priv->chans[i].num,
+ priv->chans[i].pin);
+
+ esp32_configgpio(priv->chans[i].pin, OUTPUT | PULLUP);
+ esp32_gpio_matrix_out(priv->chans[i].pin,
+ LEDC_LS_SIG_OUT0_IDX + priv->chans[i].num,
+ 0, 0);
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_shutdown
+ *
+ * Description:
+ * This method is called when the driver is closed. The lower half driver
+ * stop pulsed output, free any resources, disable the timer hardware, and
+ * put the system into the lowest possible power usage state
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ /* Stop timer */
+
+ pwm_stop(dev);
+
+ /* Clear timer and channel configuration */
+
+ priv->frequency = 0;
+ priv->reload = 0;
+ for (int i = 0; i < channels; i++)
+ {
+ priv->chans[i].duty = 0;
+ }
+
+ ledc_disable_clk();
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_start
+ *
+ * Description:
+ * (Re-)initialize the timer resources and start the pulsed output
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * info - A reference to the characteristics of the pulsed output
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ /* Update timer with given PWM timer frequency */
+
+ if (priv->frequency != info->frequency)
+ {
+ priv->frequency = info->frequency;
+ setup_timer(priv);
+ }
+
+ /* Update timer with given PWM channel duty */
+
+ for (int i = 0; i < channels; i++)
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ if (priv->chans[i].duty != info->channels[i].duty)
+#else
+ if (priv->chans[i].duty != info[i].duty)
+#endif
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ priv->chans[i].duty = info->channels[i].duty;
+#else
+ priv->chans[i].duty = info[i].duty;
+#endif
+ setup_channel(priv, i);
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_stop
+ *
+ * Description:
+ * Stop the pulsed output and reset the timer resources.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_stop(struct pwm_lowerhalf_s *dev)
+{
+ irqstate_t flags;
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ flags = enter_critical_section();
+
+ /* Stop timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PAUSE);
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ leave_critical_section(flags);
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_ioctl
+ *
+ * Description:
+ * Lower-half logic may support platform-specific ioctl commands
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * cmd - The ioctl command
+ * arg - The argument accompanying the ioctl command
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg)
+{
+#ifdef CONFIG_DEBUG_PWM_INFO
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+#endif
+
+ return -ENOTTY;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: esp32_ledc_init
+ *
+ * Description:
+ * Initialize one LEDC timer for use with the upper_level PWM driver.
+ *
+ * Input Parameters:
+ * timer - A number identifying the timer use.
+ *
+ * Returned Value:
+ * On success, a pointer to the ESP32 LEDC lower half PWM driver is
+ * returned. NULL is returned on any failure.
+ *
+ ****************************************************************************/
+
+struct pwm_lowerhalf_s *esp32_ledc_init(int timer)
+{
+ struct esp32_ledc_s *lower = NULL;
+
+ pwminfo("TIM%u\n", timer);
+
+ switch (timer)
+ {
+#ifdef CONFIG_ESP32_LEDC_TIM0
+ case 0:
+ {
+ lower = &g_pwm0dev;
+ break;
+ }
+#endif
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+ case 1:
+ {
+ lower = &g_pwm1dev;
+ break;
+ }
+#endif
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+ case 2:
+ {
+ lower = &g_pwm2dev;
+ break;
+ }
+#endif
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+ case 3:
+ {
+ lower = &g_pwm3dev;
+ break;
+ }
+#endif
+
+ default:
+ {
Review comment:
```suggestion
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
+ " reload=%" PRIu32 "\n",
+ chan->num, chan->duty, (float)chan->duty / UINT16_MAX,
+ regval, priv->reload);
+
+ flags = enter_critical_section();
+
+ /* Reset config 0 & 1 registers */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF0_REG, 0);
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF1_REG, 0);
+
+ /* Set pulse phase 0 */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_HPOINT_REG, 0);
+
+ /* Duty register uses bits [18:4] */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_DUTY_REG, regval << 4);
+
+ /* Start GPIO output */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_SIG_OUT_EN_LSCH0);
+
+ /* Start Duty counter */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF1_REG, LEDC_DUTY_START_LSCH0);
+
+ /* Update duty and phase to hardware */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_PARA_UP_LSCH0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: pwm_setup
+ *
+ * Description:
+ * This method is called when the driver is opened. The lower half driver
+ * should configure and initialize the device so that it is ready for use.
+ * It should not, however, output pulses until the start method is called.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ ledc_enable_clk();
+
+ /* Setup channel GPIO pins */
+
+ for (int i = 0; i < priv->channels; i++)
+ {
+ pwminfo("channel%d --> pin%d\n", priv->chans[i].num,
+ priv->chans[i].pin);
+
+ esp32_configgpio(priv->chans[i].pin, OUTPUT | PULLUP);
+ esp32_gpio_matrix_out(priv->chans[i].pin,
+ LEDC_LS_SIG_OUT0_IDX + priv->chans[i].num,
+ 0, 0);
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_shutdown
+ *
+ * Description:
+ * This method is called when the driver is closed. The lower half driver
+ * stop pulsed output, free any resources, disable the timer hardware, and
+ * put the system into the lowest possible power usage state
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ /* Stop timer */
+
+ pwm_stop(dev);
+
+ /* Clear timer and channel configuration */
+
+ priv->frequency = 0;
+ priv->reload = 0;
+ for (int i = 0; i < channels; i++)
+ {
+ priv->chans[i].duty = 0;
+ }
+
+ ledc_disable_clk();
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_start
+ *
+ * Description:
+ * (Re-)initialize the timer resources and start the pulsed output
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * info - A reference to the characteristics of the pulsed output
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ /* Update timer with given PWM timer frequency */
+
+ if (priv->frequency != info->frequency)
+ {
+ priv->frequency = info->frequency;
+ setup_timer(priv);
+ }
+
+ /* Update timer with given PWM channel duty */
+
+ for (int i = 0; i < channels; i++)
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ if (priv->chans[i].duty != info->channels[i].duty)
+#else
+ if (priv->chans[i].duty != info[i].duty)
+#endif
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ priv->chans[i].duty = info->channels[i].duty;
+#else
+ priv->chans[i].duty = info[i].duty;
+#endif
+ setup_channel(priv, i);
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_stop
+ *
+ * Description:
+ * Stop the pulsed output and reset the timer resources.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_stop(struct pwm_lowerhalf_s *dev)
+{
+ irqstate_t flags;
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ flags = enter_critical_section();
+
+ /* Stop timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PAUSE);
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ leave_critical_section(flags);
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_ioctl
+ *
+ * Description:
+ * Lower-half logic may support platform-specific ioctl commands
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * cmd - The ioctl command
+ * arg - The argument accompanying the ioctl command
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg)
+{
+#ifdef CONFIG_DEBUG_PWM_INFO
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+#endif
+
+ return -ENOTTY;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: esp32_ledc_init
+ *
+ * Description:
+ * Initialize one LEDC timer for use with the upper_level PWM driver.
+ *
+ * Input Parameters:
+ * timer - A number identifying the timer use.
+ *
+ * Returned Value:
+ * On success, a pointer to the ESP32 LEDC lower half PWM driver is
+ * returned. NULL is returned on any failure.
+ *
+ ****************************************************************************/
+
+struct pwm_lowerhalf_s *esp32_ledc_init(int timer)
+{
+ struct esp32_ledc_s *lower = NULL;
+
+ pwminfo("TIM%u\n", timer);
+
+ switch (timer)
+ {
+#ifdef CONFIG_ESP32_LEDC_TIM0
+ case 0:
+ {
+ lower = &g_pwm0dev;
+ break;
+ }
+#endif
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+ case 1:
+ {
+ lower = &g_pwm1dev;
+ break;
+ }
+#endif
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+ case 2:
+ {
+ lower = &g_pwm2dev;
+ break;
+ }
+#endif
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+ case 3:
+ {
+ lower = &g_pwm3dev;
+ break;
+ }
+#endif
+
+ default:
+ {
+ pwmerr("ERROR: No such timer configured %d\n", timer);
+ lower = NULL;
+ break;
+ }
Review comment:
```suggestion
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
+ " reload=%" PRIu32 "\n",
+ chan->num, chan->duty, (float)chan->duty / UINT16_MAX,
+ regval, priv->reload);
+
+ flags = enter_critical_section();
+
+ /* Reset config 0 & 1 registers */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF0_REG, 0);
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF1_REG, 0);
+
+ /* Set pulse phase 0 */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_HPOINT_REG, 0);
+
+ /* Duty register uses bits [18:4] */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_DUTY_REG, regval << 4);
+
+ /* Start GPIO output */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_SIG_OUT_EN_LSCH0);
+
+ /* Start Duty counter */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF1_REG, LEDC_DUTY_START_LSCH0);
+
+ /* Update duty and phase to hardware */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_PARA_UP_LSCH0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: pwm_setup
+ *
+ * Description:
+ * This method is called when the driver is opened. The lower half driver
+ * should configure and initialize the device so that it is ready for use.
+ * It should not, however, output pulses until the start method is called.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ ledc_enable_clk();
+
+ /* Setup channel GPIO pins */
+
+ for (int i = 0; i < priv->channels; i++)
+ {
+ pwminfo("channel%d --> pin%d\n", priv->chans[i].num,
+ priv->chans[i].pin);
+
+ esp32_configgpio(priv->chans[i].pin, OUTPUT | PULLUP);
+ esp32_gpio_matrix_out(priv->chans[i].pin,
+ LEDC_LS_SIG_OUT0_IDX + priv->chans[i].num,
+ 0, 0);
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_shutdown
+ *
+ * Description:
+ * This method is called when the driver is closed. The lower half driver
+ * stop pulsed output, free any resources, disable the timer hardware, and
+ * put the system into the lowest possible power usage state
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ /* Stop timer */
+
+ pwm_stop(dev);
+
+ /* Clear timer and channel configuration */
+
+ priv->frequency = 0;
+ priv->reload = 0;
+ for (int i = 0; i < channels; i++)
+ {
+ priv->chans[i].duty = 0;
+ }
+
+ ledc_disable_clk();
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_start
+ *
+ * Description:
+ * (Re-)initialize the timer resources and start the pulsed output
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * info - A reference to the characteristics of the pulsed output
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ /* Update timer with given PWM timer frequency */
+
+ if (priv->frequency != info->frequency)
+ {
+ priv->frequency = info->frequency;
+ setup_timer(priv);
+ }
+
+ /* Update timer with given PWM channel duty */
+
+ for (int i = 0; i < channels; i++)
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ if (priv->chans[i].duty != info->channels[i].duty)
+#else
+ if (priv->chans[i].duty != info[i].duty)
+#endif
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ priv->chans[i].duty = info->channels[i].duty;
+#else
+ priv->chans[i].duty = info[i].duty;
+#endif
+ setup_channel(priv, i);
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_stop
+ *
+ * Description:
+ * Stop the pulsed output and reset the timer resources.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_stop(struct pwm_lowerhalf_s *dev)
+{
+ irqstate_t flags;
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ flags = enter_critical_section();
+
+ /* Stop timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PAUSE);
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ leave_critical_section(flags);
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_ioctl
+ *
+ * Description:
+ * Lower-half logic may support platform-specific ioctl commands
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * cmd - The ioctl command
+ * arg - The argument accompanying the ioctl command
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg)
+{
+#ifdef CONFIG_DEBUG_PWM_INFO
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+#endif
+
+ return -ENOTTY;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: esp32_ledc_init
+ *
+ * Description:
+ * Initialize one LEDC timer for use with the upper_level PWM driver.
+ *
+ * Input Parameters:
+ * timer - A number identifying the timer use.
+ *
+ * Returned Value:
+ * On success, a pointer to the ESP32 LEDC lower half PWM driver is
+ * returned. NULL is returned on any failure.
+ *
+ ****************************************************************************/
+
+struct pwm_lowerhalf_s *esp32_ledc_init(int timer)
+{
+ struct esp32_ledc_s *lower = NULL;
+
+ pwminfo("TIM%u\n", timer);
+
+ switch (timer)
+ {
+#ifdef CONFIG_ESP32_LEDC_TIM0
+ case 0:
+ {
+ lower = &g_pwm0dev;
+ break;
+ }
Review comment:
```suggestion
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
+ " reload=%" PRIu32 "\n",
+ chan->num, chan->duty, (float)chan->duty / UINT16_MAX,
+ regval, priv->reload);
+
+ flags = enter_critical_section();
+
+ /* Reset config 0 & 1 registers */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF0_REG, 0);
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF1_REG, 0);
+
+ /* Set pulse phase 0 */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_HPOINT_REG, 0);
+
+ /* Duty register uses bits [18:4] */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_DUTY_REG, regval << 4);
+
+ /* Start GPIO output */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_SIG_OUT_EN_LSCH0);
+
+ /* Start Duty counter */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF1_REG, LEDC_DUTY_START_LSCH0);
+
+ /* Update duty and phase to hardware */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_PARA_UP_LSCH0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: pwm_setup
+ *
+ * Description:
+ * This method is called when the driver is opened. The lower half driver
+ * should configure and initialize the device so that it is ready for use.
+ * It should not, however, output pulses until the start method is called.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ ledc_enable_clk();
+
+ /* Setup channel GPIO pins */
+
+ for (int i = 0; i < priv->channels; i++)
+ {
+ pwminfo("channel%d --> pin%d\n", priv->chans[i].num,
+ priv->chans[i].pin);
+
+ esp32_configgpio(priv->chans[i].pin, OUTPUT | PULLUP);
+ esp32_gpio_matrix_out(priv->chans[i].pin,
+ LEDC_LS_SIG_OUT0_IDX + priv->chans[i].num,
+ 0, 0);
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_shutdown
+ *
+ * Description:
+ * This method is called when the driver is closed. The lower half driver
+ * stop pulsed output, free any resources, disable the timer hardware, and
+ * put the system into the lowest possible power usage state
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ /* Stop timer */
+
+ pwm_stop(dev);
+
+ /* Clear timer and channel configuration */
+
+ priv->frequency = 0;
+ priv->reload = 0;
+ for (int i = 0; i < channels; i++)
+ {
+ priv->chans[i].duty = 0;
+ }
+
+ ledc_disable_clk();
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_start
+ *
+ * Description:
+ * (Re-)initialize the timer resources and start the pulsed output
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * info - A reference to the characteristics of the pulsed output
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ /* Update timer with given PWM timer frequency */
+
+ if (priv->frequency != info->frequency)
+ {
+ priv->frequency = info->frequency;
+ setup_timer(priv);
+ }
+
+ /* Update timer with given PWM channel duty */
+
+ for (int i = 0; i < channels; i++)
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ if (priv->chans[i].duty != info->channels[i].duty)
+#else
+ if (priv->chans[i].duty != info[i].duty)
+#endif
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ priv->chans[i].duty = info->channels[i].duty;
+#else
+ priv->chans[i].duty = info[i].duty;
+#endif
+ setup_channel(priv, i);
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_stop
+ *
+ * Description:
+ * Stop the pulsed output and reset the timer resources.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_stop(struct pwm_lowerhalf_s *dev)
+{
+ irqstate_t flags;
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ flags = enter_critical_section();
+
+ /* Stop timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PAUSE);
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ leave_critical_section(flags);
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_ioctl
+ *
+ * Description:
+ * Lower-half logic may support platform-specific ioctl commands
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * cmd - The ioctl command
+ * arg - The argument accompanying the ioctl command
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg)
+{
+#ifdef CONFIG_DEBUG_PWM_INFO
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
Review comment:
```suggestion
pwminfo("PWM timer%u\n", priv->num);
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
+ " reload=%" PRIu32 "\n",
+ chan->num, chan->duty, (float)chan->duty / UINT16_MAX,
+ regval, priv->reload);
+
+ flags = enter_critical_section();
+
+ /* Reset config 0 & 1 registers */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF0_REG, 0);
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF1_REG, 0);
+
+ /* Set pulse phase 0 */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_HPOINT_REG, 0);
+
+ /* Duty register uses bits [18:4] */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_DUTY_REG, regval << 4);
+
+ /* Start GPIO output */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_SIG_OUT_EN_LSCH0);
+
+ /* Start Duty counter */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF1_REG, LEDC_DUTY_START_LSCH0);
+
+ /* Update duty and phase to hardware */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_PARA_UP_LSCH0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: pwm_setup
+ *
+ * Description:
+ * This method is called when the driver is opened. The lower half driver
+ * should configure and initialize the device so that it is ready for use.
+ * It should not, however, output pulses until the start method is called.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ ledc_enable_clk();
+
+ /* Setup channel GPIO pins */
+
+ for (int i = 0; i < priv->channels; i++)
+ {
+ pwminfo("channel%d --> pin%d\n", priv->chans[i].num,
+ priv->chans[i].pin);
+
+ esp32_configgpio(priv->chans[i].pin, OUTPUT | PULLUP);
+ esp32_gpio_matrix_out(priv->chans[i].pin,
+ LEDC_LS_SIG_OUT0_IDX + priv->chans[i].num,
+ 0, 0);
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_shutdown
+ *
+ * Description:
+ * This method is called when the driver is closed. The lower half driver
+ * stop pulsed output, free any resources, disable the timer hardware, and
+ * put the system into the lowest possible power usage state
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ /* Stop timer */
+
+ pwm_stop(dev);
+
+ /* Clear timer and channel configuration */
+
+ priv->frequency = 0;
+ priv->reload = 0;
+ for (int i = 0; i < channels; i++)
+ {
+ priv->chans[i].duty = 0;
+ }
+
+ ledc_disable_clk();
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_start
+ *
+ * Description:
+ * (Re-)initialize the timer resources and start the pulsed output
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * info - A reference to the characteristics of the pulsed output
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ /* Update timer with given PWM timer frequency */
+
+ if (priv->frequency != info->frequency)
+ {
+ priv->frequency = info->frequency;
+ setup_timer(priv);
+ }
+
+ /* Update timer with given PWM channel duty */
+
+ for (int i = 0; i < channels; i++)
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ if (priv->chans[i].duty != info->channels[i].duty)
+#else
+ if (priv->chans[i].duty != info[i].duty)
+#endif
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ priv->chans[i].duty = info->channels[i].duty;
+#else
+ priv->chans[i].duty = info[i].duty;
+#endif
+ setup_channel(priv, i);
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_stop
+ *
+ * Description:
+ * Stop the pulsed output and reset the timer resources.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_stop(struct pwm_lowerhalf_s *dev)
+{
+ irqstate_t flags;
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ flags = enter_critical_section();
+
+ /* Stop timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PAUSE);
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ leave_critical_section(flags);
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_ioctl
+ *
+ * Description:
+ * Lower-half logic may support platform-specific ioctl commands
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * cmd - The ioctl command
+ * arg - The argument accompanying the ioctl command
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg)
+{
+#ifdef CONFIG_DEBUG_PWM_INFO
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+#endif
+
+ return -ENOTTY;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: esp32_ledc_init
+ *
+ * Description:
+ * Initialize one LEDC timer for use with the upper_level PWM driver.
+ *
+ * Input Parameters:
+ * timer - A number identifying the timer use.
+ *
+ * Returned Value:
+ * On success, a pointer to the ESP32 LEDC lower half PWM driver is
+ * returned. NULL is returned on any failure.
+ *
+ ****************************************************************************/
+
+struct pwm_lowerhalf_s *esp32_ledc_init(int timer)
+{
+ struct esp32_ledc_s *lower = NULL;
+
+ pwminfo("TIM%u\n", timer);
Review comment:
```suggestion
pwminfo("TIM%d\n", timer);
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
Review comment:
```suggestion
* None
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
Review comment:
```suggestion
* None
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
+ " reload=%" PRIu32 "\n",
+ chan->num, chan->duty, (float)chan->duty / UINT16_MAX,
+ regval, priv->reload);
+
+ flags = enter_critical_section();
+
+ /* Reset config 0 & 1 registers */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF0_REG, 0);
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF1_REG, 0);
+
+ /* Set pulse phase 0 */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_HPOINT_REG, 0);
+
+ /* Duty register uses bits [18:4] */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_DUTY_REG, regval << 4);
+
+ /* Start GPIO output */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_SIG_OUT_EN_LSCH0);
+
+ /* Start Duty counter */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF1_REG, LEDC_DUTY_START_LSCH0);
+
+ /* Update duty and phase to hardware */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_PARA_UP_LSCH0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: pwm_setup
+ *
+ * Description:
+ * This method is called when the driver is opened. The lower half driver
+ * should configure and initialize the device so that it is ready for use.
+ * It should not, however, output pulses until the start method is called.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ ledc_enable_clk();
+
+ /* Setup channel GPIO pins */
+
+ for (int i = 0; i < priv->channels; i++)
+ {
+ pwminfo("channel%d --> pin%d\n", priv->chans[i].num,
+ priv->chans[i].pin);
+
+ esp32_configgpio(priv->chans[i].pin, OUTPUT | PULLUP);
+ esp32_gpio_matrix_out(priv->chans[i].pin,
+ LEDC_LS_SIG_OUT0_IDX + priv->chans[i].num,
+ 0, 0);
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_shutdown
+ *
+ * Description:
+ * This method is called when the driver is closed. The lower half driver
+ * stop pulsed output, free any resources, disable the timer hardware, and
+ * put the system into the lowest possible power usage state
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ /* Stop timer */
+
+ pwm_stop(dev);
+
+ /* Clear timer and channel configuration */
+
+ priv->frequency = 0;
+ priv->reload = 0;
+ for (int i = 0; i < channels; i++)
+ {
+ priv->chans[i].duty = 0;
+ }
+
+ ledc_disable_clk();
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_start
+ *
+ * Description:
+ * (Re-)initialize the timer resources and start the pulsed output
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * info - A reference to the characteristics of the pulsed output
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ pwminfo("PWM timer%d\n", priv->num);
Review comment:
```suggestion
pwminfo("PWM timer%u\n", priv->num);
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
+ " reload=%" PRIu32 "\n",
+ chan->num, chan->duty, (float)chan->duty / UINT16_MAX,
+ regval, priv->reload);
+
+ flags = enter_critical_section();
+
+ /* Reset config 0 & 1 registers */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF0_REG, 0);
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF1_REG, 0);
+
+ /* Set pulse phase 0 */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_HPOINT_REG, 0);
+
+ /* Duty register uses bits [18:4] */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_DUTY_REG, regval << 4);
+
+ /* Start GPIO output */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_SIG_OUT_EN_LSCH0);
+
+ /* Start Duty counter */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF1_REG, LEDC_DUTY_START_LSCH0);
+
+ /* Update duty and phase to hardware */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_PARA_UP_LSCH0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: pwm_setup
+ *
+ * Description:
+ * This method is called when the driver is opened. The lower half driver
+ * should configure and initialize the device so that it is ready for use.
+ * It should not, however, output pulses until the start method is called.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ ledc_enable_clk();
+
+ /* Setup channel GPIO pins */
+
+ for (int i = 0; i < priv->channels; i++)
+ {
+ pwminfo("channel%d --> pin%d\n", priv->chans[i].num,
Review comment:
```suggestion
pwminfo("channel%u --> pin%u\n", priv->chans[i].num,
```
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[GitHub] [incubator-nuttx] acassis commented on a change in pull request #5187: esp32: Add PWM support using the LEDC peripheral
Posted by GitBox <gi...@apache.org>.
acassis commented on a change in pull request #5187:
URL: https://github.com/apache/incubator-nuttx/pull/5187#discussion_r780233682
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,812 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
Review comment:
Unfortunately we cannot remove this defined(CONFIG_PWM_NCHANNELS), otherwise it will generate a warning when PWM_NCHANNELS is not used:
```
chip/esp32_ledc.c:52:5: warning: "CONFIG_PWM_NCHANNELS" is not defined, evaluates to 0 [-Wundef]
#if CONFIG_PWM_NCHANNELS > 1
^~~~~~~~~~~~~~~~~~~~
```
When "#if defined(CONFIG_PWM_NCHANNELS) && ..." is present the second part is not tested and the warning doesn't show up!
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[GitHub] [incubator-nuttx] pkarashchenko commented on a change in pull request #5187: esp32: Add PWM support using the LEDC peripheral
Posted by GitBox <gi...@apache.org>.
pkarashchenko commented on a change in pull request #5187:
URL: https://github.com/apache/incubator-nuttx/pull/5187#discussion_r780111691
##########
File path: arch/xtensa/src/esp32/Kconfig
##########
@@ -1282,6 +1283,91 @@ config ESP32_FREERUN
endmenu # Timer/counter Configuration
endif # ESP32_TIMER
+menu "LEDC configuration"
+ depends on ESP32_LEDC
Review comment:
```suggestion
depends on ESP32_LEDC
```
##########
File path: arch/xtensa/src/esp32/Kconfig
##########
@@ -1282,6 +1283,91 @@ config ESP32_FREERUN
endmenu # Timer/counter Configuration
endif # ESP32_TIMER
+menu "LEDC configuration"
+ depends on ESP32_LEDC
+
+menuconfig ESP32_LEDC_TIM0
+ bool "Timer 0"
+ default n
Review comment:
```suggestion
bool "Timer 0"
default n
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,812 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
Review comment:
I think that next code should be enough
```suggestion
# if CONFIG_PWM_NCHANNELS > 1
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
+ " reload=%" PRIu32 "\n",
+ chan->num, chan->duty, (float)chan->duty / UINT16_MAX,
+ regval, priv->reload);
+
+ flags = enter_critical_section();
+
+ /* Reset config 0 & 1 registers */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF0_REG, 0);
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF1_REG, 0);
+
+ /* Set pulse phase 0 */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_HPOINT_REG, 0);
+
+ /* Duty register uses bits [18:4] */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_DUTY_REG, regval << 4);
+
+ /* Start GPIO output */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_SIG_OUT_EN_LSCH0);
+
+ /* Start Duty counter */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF1_REG, LEDC_DUTY_START_LSCH0);
+
+ /* Update duty and phase to hardware */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_PARA_UP_LSCH0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: pwm_setup
+ *
+ * Description:
+ * This method is called when the driver is opened. The lower half driver
+ * should configure and initialize the device so that it is ready for use.
+ * It should not, however, output pulses until the start method is called.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ ledc_enable_clk();
+
+ /* Setup channel GPIO pins */
+
+ for (int i = 0; i < priv->channels; i++)
+ {
+ pwminfo("channel%d --> pin%d\n", priv->chans[i].num,
Review comment:
@acassis do you plan to integrate this change?
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
+ " reload=%" PRIu32 "\n",
+ chan->num, chan->duty, (float)chan->duty / UINT16_MAX,
+ regval, priv->reload);
+
+ flags = enter_critical_section();
+
+ /* Reset config 0 & 1 registers */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF0_REG, 0);
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF1_REG, 0);
+
+ /* Set pulse phase 0 */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_HPOINT_REG, 0);
+
+ /* Duty register uses bits [18:4] */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_DUTY_REG, regval << 4);
+
+ /* Start GPIO output */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_SIG_OUT_EN_LSCH0);
+
+ /* Start Duty counter */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF1_REG, LEDC_DUTY_START_LSCH0);
+
+ /* Update duty and phase to hardware */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_PARA_UP_LSCH0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: pwm_setup
+ *
+ * Description:
+ * This method is called when the driver is opened. The lower half driver
+ * should configure and initialize the device so that it is ready for use.
+ * It should not, however, output pulses until the start method is called.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ ledc_enable_clk();
+
+ /* Setup channel GPIO pins */
+
+ for (int i = 0; i < priv->channels; i++)
+ {
+ pwminfo("channel%d --> pin%d\n", priv->chans[i].num,
+ priv->chans[i].pin);
+
+ esp32_configgpio(priv->chans[i].pin, OUTPUT | PULLUP);
+ esp32_gpio_matrix_out(priv->chans[i].pin,
+ LEDC_LS_SIG_OUT0_IDX + priv->chans[i].num,
+ 0, 0);
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_shutdown
+ *
+ * Description:
+ * This method is called when the driver is closed. The lower half driver
+ * stop pulsed output, free any resources, disable the timer hardware, and
+ * put the system into the lowest possible power usage state
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ /* Stop timer */
+
+ pwm_stop(dev);
+
+ /* Clear timer and channel configuration */
+
+ priv->frequency = 0;
+ priv->reload = 0;
+ for (int i = 0; i < channels; i++)
+ {
+ priv->chans[i].duty = 0;
+ }
+
+ ledc_disable_clk();
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_start
+ *
+ * Description:
+ * (Re-)initialize the timer resources and start the pulsed output
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * info - A reference to the characteristics of the pulsed output
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ pwminfo("PWM timer%d\n", priv->num);
Review comment:
@acassis do you plan to integrate this change?
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
+ " reload=%" PRIu32 "\n",
+ chan->num, chan->duty, (float)chan->duty / UINT16_MAX,
+ regval, priv->reload);
+
+ flags = enter_critical_section();
+
+ /* Reset config 0 & 1 registers */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF0_REG, 0);
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF1_REG, 0);
+
+ /* Set pulse phase 0 */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_HPOINT_REG, 0);
+
+ /* Duty register uses bits [18:4] */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_DUTY_REG, regval << 4);
+
+ /* Start GPIO output */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_SIG_OUT_EN_LSCH0);
+
+ /* Start Duty counter */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF1_REG, LEDC_DUTY_START_LSCH0);
+
+ /* Update duty and phase to hardware */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_PARA_UP_LSCH0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: pwm_setup
+ *
+ * Description:
+ * This method is called when the driver is opened. The lower half driver
+ * should configure and initialize the device so that it is ready for use.
+ * It should not, however, output pulses until the start method is called.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ ledc_enable_clk();
+
+ /* Setup channel GPIO pins */
+
+ for (int i = 0; i < priv->channels; i++)
+ {
+ pwminfo("channel%d --> pin%d\n", priv->chans[i].num,
+ priv->chans[i].pin);
+
+ esp32_configgpio(priv->chans[i].pin, OUTPUT | PULLUP);
+ esp32_gpio_matrix_out(priv->chans[i].pin,
+ LEDC_LS_SIG_OUT0_IDX + priv->chans[i].num,
+ 0, 0);
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_shutdown
+ *
+ * Description:
+ * This method is called when the driver is closed. The lower half driver
+ * stop pulsed output, free any resources, disable the timer hardware, and
+ * put the system into the lowest possible power usage state
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ /* Stop timer */
+
+ pwm_stop(dev);
+
+ /* Clear timer and channel configuration */
+
+ priv->frequency = 0;
+ priv->reload = 0;
+ for (int i = 0; i < channels; i++)
+ {
+ priv->chans[i].duty = 0;
+ }
+
+ ledc_disable_clk();
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_start
+ *
+ * Description:
+ * (Re-)initialize the timer resources and start the pulsed output
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ * info - A reference to the characteristics of the pulsed output
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+#ifdef CONFIG_PWM_NCHANNELS
+ int channels = MIN(priv->channels, CONFIG_PWM_NCHANNELS);
+#else
+ int channels = 1;
+#endif
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ /* Update timer with given PWM timer frequency */
+
+ if (priv->frequency != info->frequency)
+ {
+ priv->frequency = info->frequency;
+ setup_timer(priv);
+ }
+
+ /* Update timer with given PWM channel duty */
+
+ for (int i = 0; i < channels; i++)
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ if (priv->chans[i].duty != info->channels[i].duty)
+#else
+ if (priv->chans[i].duty != info[i].duty)
+#endif
+ {
+#ifdef CONFIG_PWM_NCHANNELS
+ priv->chans[i].duty = info->channels[i].duty;
+#else
+ priv->chans[i].duty = info[i].duty;
+#endif
+ setup_channel(priv, i);
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ * Name: pwm_stop
+ *
+ * Description:
+ * Stop the pulsed output and reset the timer resources.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_stop(struct pwm_lowerhalf_s *dev)
+{
+ irqstate_t flags;
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
Review comment:
@acassis do you plan to integrate this change?
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[GitHub] [incubator-nuttx] acassis commented on a change in pull request #5187: esp32: Add PWM support using the LEDC peripheral
Posted by GitBox <gi...@apache.org>.
acassis commented on a change in pull request #5187:
URL: https://github.com/apache/incubator-nuttx/pull/5187#discussion_r780233682
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,812 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
Review comment:
Unfortunately we cannot remove this defined(CONFIG_PWM_NCHANNELS), otherwise it will generate a warning when PWM_NCHANNELS is not used:
```
chip/esp32_ledc.c:52:5: warning: "CONFIG_PWM_NCHANNELS" is not defined, evaluates to 0 [-Wundef]
#if CONFIG_PWM_NCHANNELS > 1
^~~~~~~~~~~~~~~~~~~~
```
When "#if defined(CONFIG_PWM_NCHANNELS) && ..." is present the send part is not tested and the warning doesn't show up!
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[GitHub] [incubator-nuttx] pkarashchenko merged pull request #5187: esp32: Add PWM support using the LEDC peripheral
Posted by GitBox <gi...@apache.org>.
pkarashchenko merged pull request #5187:
URL: https://github.com/apache/incubator-nuttx/pull/5187
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[GitHub] [incubator-nuttx] pkarashchenko commented on a change in pull request #5187: esp32: Add PWM support using the LEDC peripheral
Posted by GitBox <gi...@apache.org>.
pkarashchenko commented on a change in pull request #5187:
URL: https://github.com/apache/incubator-nuttx/pull/5187#discussion_r780111691
##########
File path: arch/xtensa/src/esp32/Kconfig
##########
@@ -1282,6 +1283,91 @@ config ESP32_FREERUN
endmenu # Timer/counter Configuration
endif # ESP32_TIMER
+menu "LEDC configuration"
+ depends on ESP32_LEDC
Review comment:
```suggestion
depends on ESP32_LEDC
```
##########
File path: arch/xtensa/src/esp32/Kconfig
##########
@@ -1282,6 +1283,91 @@ config ESP32_FREERUN
endmenu # Timer/counter Configuration
endif # ESP32_TIMER
+menu "LEDC configuration"
+ depends on ESP32_LEDC
+
+menuconfig ESP32_LEDC_TIM0
+ bool "Timer 0"
+ default n
Review comment:
```suggestion
bool "Timer 0"
default n
```
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,812 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
Review comment:
I think that next code should be enough
```suggestion
# if CONFIG_PWM_NCHANNELS > 1
```
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[GitHub] [incubator-nuttx] pkarashchenko commented on a change in pull request #5187: esp32: Add PWM support using the LEDC peripheral
Posted by GitBox <gi...@apache.org>.
pkarashchenko commented on a change in pull request #5187:
URL: https://github.com/apache/incubator-nuttx/pull/5187#discussion_r780244979
##########
File path: arch/xtensa/src/esp32/esp32_ledc.c
##########
@@ -0,0 +1,822 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32/esp32_ledc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "esp32_clockconfig.h"
+#include "esp32_gpio.h"
+#include "esp32_ledc.h"
+
+#include "xtensa.h"
+#include "hardware/esp32_ledc.h"
+#include "hardware/esp32_dport.h"
+#include "hardware/esp32_gpio_sigmap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* LEDC total timers */
+
+#define LEDC_TIMERS (4)
+
+/* LEDC total channels */
+
+#if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_CHANNELS (8)
+#else
+# define LEDC_CHANNELS (4)
+#endif
+
+/* LEDC timer0 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM0_CHANS CONFIG_ESP32_LEDC_TIM0_CHANNELS
+# else
+# define LEDC_TIM0_CHANS (1)
+# endif
+# define LEDC_TIM0_CHANS_OFF (0)
+#endif
+
+/* LEDC timer1 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM1_CHANS CONFIG_ESP32_LEDC_TIM1_CHANNELS
+# else
+# define LEDC_TIM1_CHANS (1)
+# endif
+# define LEDC_TIM1_CHANS_OFF (LEDC_TIM0_CHANS_OFF + LEDC_TIM0_CHANS)
+#endif
+
+/* LEDC timer2 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM2_CHANS CONFIG_ESP32_LEDC_TIM2_CHANNELS
+# else
+# define LEDC_TIM2_CHANS (1)
+# endif
+
+# define LEDC_TIM2_CHANS_OFF (LEDC_TIM1_CHANS_OFF + LEDC_TIM1_CHANS)
+#endif
+
+/* LEDC timer3 channels and offset */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+# if defined(CONFIG_PWM_NCHANNELS) && CONFIG_PWM_NCHANNELS > 1
+# define LEDC_TIM3_CHANS CONFIG_ESP32_LEDC_TIM3_CHANNELS
+# else
+# define LEDC_TIM3_CHANS (1)
+# endif
+
+# define LEDC_TIM3_CHANS_OFF (LEDC_TIM2_CHANS_OFF + LEDC_TIM2_CHANS)
+#endif
+
+/* LEDC clock resource */
+
+#define LEDC_CLK_RES (1) /* APB clock */
+
+/* LEDC timer max reload */
+
+#define LEDC_RELOAD_MAX (1048576) /* 2^20 */
+
+/* LEDC timer max clock divider parameter */
+
+#define LEDC_CLKDIV_MAX (1024) /* 2^10 */
+
+/* LEDC timer registers mapping */
+
+#define LEDC_TIMER_REG(r, n) ((r) + (n) * (LEDC_LSTIMER1_CONF_REG - \
+ LEDC_LSTIMER0_CONF_REG))
+
+/* LEDC timer channel registers mapping */
+
+#define setbits(bs, a) modifyreg32(a, 0, bs)
+#define resetbits(bs, a) modifyreg32(a, bs, 0)
+
+#define LEDC_CHAN_REG(r, n) ((r) + (n) * (LEDC_LSCH1_CONF0_REG - \
+ LEDC_LSCH0_CONF0_REG))
+
+#define SET_TIMER_BITS(t, r, b) setbits(b, LEDC_TIMER_REG(r, (t)->num));
+#define SET_TIMER_REG(t, r, v) putreg32(v, LEDC_TIMER_REG(r, (t)->num));
+
+#define SET_CHAN_BITS(c, r, b) setbits(b, LEDC_CHAN_REG(r, (c)->num));
+#define SET_CHAN_REG(c, r, v) putreg32(v, LEDC_CHAN_REG(r, (c)->num));
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* LEDC timer channel configuration */
+
+struct esp32_ledc_chan_s
+{
+ const uint8_t num; /* Timer channel ID */
+ const uint8_t pin; /* Timer channel GPIO pin number */
+
+ uint16_t duty; /* Timer channel current duty */
+};
+
+/* This structure represents the state of one LEDC timer */
+
+struct esp32_ledc_s
+{
+ const struct pwm_ops_s *ops; /* PWM operations */
+
+ const uint8_t num; /* Timer ID */
+
+ const uint8_t channels; /* Timer channels number */
+ struct esp32_ledc_chan_s *chans; /* Timer channels pointer */
+
+ uint32_t frequency; /* Timer current frequency */
+ uint32_t reload; /* Timer current reload */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev);
+static int pwm_shutdown(struct pwm_lowerhalf_s *dev);
+static int pwm_start(struct pwm_lowerhalf_s *dev,
+ const struct pwm_info_s *info);
+static int pwm_stop(struct pwm_lowerhalf_s *dev);
+static int pwm_ioctl(struct pwm_lowerhalf_s *dev, int cmd,
+ unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* LEDC PWM operations */
+
+static const struct pwm_ops_s g_pwmops =
+{
+ .setup = pwm_setup,
+ .shutdown = pwm_shutdown,
+ .start = pwm_start,
+ .stop = pwm_stop,
+ .ioctl = pwm_ioctl
+};
+
+/* LEDC channels table */
+
+static struct esp32_ledc_chan_s g_ledc_chans[LEDC_CHANNELS] =
+{
+ {
+ .num = 0,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL0_PIN
+ },
+
+ {
+ .num = 1,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL1_PIN
+ },
+
+ {
+ .num = 2,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL2_PIN
+ },
+
+ {
+ .num = 3,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL3_PIN
+ },
+
+#if LEDC_CHANNELS > 4
+ {
+ .num = 4,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL4_PIN
+ },
+
+ {
+ .num = 5,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL5_PIN
+ },
+
+ {
+ .num = 6,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL6_PIN
+ },
+
+ {
+ .num = 7,
+ .pin = CONFIG_ESP32_LEDC_CHANNEL7_PIN
+ }
+#endif
+};
+
+/* LEDC timer0 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM0
+static struct esp32_ledc_s g_pwm0dev =
+{
+ .ops = &g_pwmops,
+ .num = 0,
+ .channels = LEDC_TIM0_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM0_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM0 */
+
+/* LEDC timer1 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM1
+static struct esp32_ledc_s g_pwm1dev =
+{
+ .ops = &g_pwmops,
+ .num = 1,
+ .channels = LEDC_TIM1_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM1_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM1 */
+
+/* LEDC timer2 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM2
+static struct esp32_ledc_s g_pwm2dev =
+{
+ .ops = &g_pwmops,
+ .num = 2,
+ .channels = LEDC_TIM2_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM2_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM2 */
+
+/* LEDC timer3 private data */
+
+#ifdef CONFIG_ESP32_LEDC_TIM3
+static struct esp32_ledc_s g_pwm3dev =
+{
+ .ops = &g_pwmops,
+ .num = 3,
+ .channels = LEDC_TIM3_CHANS,
+ .chans = &g_ledc_chans[LEDC_TIM3_CHANS_OFF]
+};
+#endif /* CONFIG_ESP32_LEDC_TIM3 */
+
+/* Clock reference count */
+
+static uint32_t g_clk_ref;
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ledc_enable_clk
+ *
+ * Description:
+ * Enable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_enable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ if (!g_clk_ref)
+ {
+ setbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ resetbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+
+ putreg32(LEDC_CLK_RES, LEDC_CONF_REG);
+
+ pwminfo("Enable ledc clock\n");
+ }
+
+ g_clk_ref++;
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: ledc_disable_clk
+ *
+ * Description:
+ * Disable LEDC clock.
+ *
+ * Input Parameters:
+ * NOne
+ *
+ * Returned Value:
+ * None.
+ *
+ ****************************************************************************/
+
+static void ledc_disable_clk(void)
+{
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+
+ g_clk_ref--;
+
+ if (!g_clk_ref)
+ {
+ pwminfo("Disable ledc clock\n");
+
+ setbits(DPORT_LEDC_RST, DPORT_PERIP_RST_EN_REG);
+ resetbits(DPORT_LEDC_CLK_EN, DPORT_PERIP_CLK_EN_REG);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_timer
+ *
+ * Description:
+ * Setup LEDC timer frequency and reload.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_timer(struct esp32_ledc_s *priv)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ uint32_t reload;
+ uint32_t prescaler;
+ uint32_t shift = 1;
+ uint64_t pwmclk = esp_clk_apb_freq();
+
+ /* Reset timer */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_RST);
+
+ /* Calculate optimal values for the timer prescaler and for the timer
+ * modulo register. If' frequency' is the desired frequency, then
+ *
+ * tpmclk = pwmclk / presc
+ * frequency = tpmclk / reload
+ *
+ * ==>
+ *
+ * reload = pwmclk / presc / frequency
+ *
+ * In ESP32, there are 2 clock resources for PWM:
+ *
+ * 1. APB clock (80 MHz)
+ * 2. RTC clock (8 MHz)
+ *
+ * We mostly use APB clock generally.
+ *
+ * There are many solutions to this, but the best solution will be the one
+ * that has the largest reload value and the smallest prescaler value.
+ * That is the solution that should give us the most accuracy in the timer
+ * control. Subject to:
+ *
+ * 2 <= presc <= 2^20(1,048,576)
+ * 1 <= clkdiv <= 2^10
+ *
+ * clkdiv has 8-bit decimal precision, so
+ * clkdiv = pwmclk * 256 / 1048576 / frequency would be optimal.
+ *
+ * Example:
+ *
+ * pwmclk = 80 MHz
+ * frequency = 100 Hz
+ *
+ * presc = 80,000,000 * 256 / 16,384 / 100
+ * = 12,500
+ * timclk = 80,000,000 / (12,500 / 256)
+ * = 1,638,400
+ * counter = 1,638,400 / 100
+ * = 16,384
+ * = 2^14
+ * shift = 14
+ */
+
+ reload = (pwmclk * 256 / priv->frequency + LEDC_CLKDIV_MAX) /
+ LEDC_CLKDIV_MAX;
+ if (reload == 0)
+ {
+ reload = 1;
+ }
+ else if (reload > LEDC_RELOAD_MAX)
+ {
+ reload = LEDC_RELOAD_MAX;
+ }
+
+ for (int c = 2; c <= LEDC_RELOAD_MAX; c *= 2)
+ {
+ if (c * 2 > reload)
+ {
+ reload = c;
+ break;
+ }
+
+ shift++;
+ }
+
+ prescaler = pwmclk * 256 / reload / priv->frequency;
+
+ pwminfo("PWM timer%" PRIu8 " frequency=%0.4f reload=%" PRIu32 " shift=%" \
+ PRIu32 " prescaler=%0.4f\n",
+ priv->num, (float)pwmclk / reload / ((float)prescaler / 256),
+ reload, shift, (float)prescaler / 256);
+
+ /* Store reload for channel duty */
+
+ priv->reload = reload;
+
+ flags = enter_critical_section();
+
+ /* Set timer clock divide and reload */
+
+ regval = (shift << LEDC_LSTIMER0_DUTY_RES_S) |
+ (prescaler << LEDC_DIV_NUM_LSTIMER0_S);
+ SET_TIMER_REG(priv, LEDC_LSTIMER0_CONF_REG, regval);
+
+ /* Setup to timer to use APB clock (80MHz) */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_TICK_SEL_LSTIMER0);
+
+ /* Update clock divide and reload to hardware */
+
+ SET_TIMER_BITS(priv, LEDC_LSTIMER0_CONF_REG, LEDC_LSTIMER0_PARA_UP);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: setup_channel
+ *
+ * Description:
+ * Setup LEDC timer channel duty.
+ *
+ * Input Parameters:
+ * priv - A reference to the LEDC timer state structure
+ * cn - Timer channel number
+ *
+ * Returned Value:
+ * None
+ *
+ ****************************************************************************/
+
+static void setup_channel(struct esp32_ledc_s *priv, int cn)
+{
+ irqstate_t flags;
+ uint32_t regval;
+ struct esp32_ledc_chan_s *chan = &priv->chans[cn];
+
+ /* Duty cycle:
+ *
+ * duty cycle = duty / 65536 * reload (fractional value)
+ */
+
+ regval = b16toi(chan->duty * priv->reload + b16HALF);
+
+ pwminfo("channel=%" PRIu8 " duty=%" PRIu16 "(%0.4f) regval=%" PRIu32 \
+ " reload=%" PRIu32 "\n",
+ chan->num, chan->duty, (float)chan->duty / UINT16_MAX,
+ regval, priv->reload);
+
+ flags = enter_critical_section();
+
+ /* Reset config 0 & 1 registers */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF0_REG, 0);
+ SET_CHAN_REG(chan, LEDC_LSCH0_CONF1_REG, 0);
+
+ /* Set pulse phase 0 */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_HPOINT_REG, 0);
+
+ /* Duty register uses bits [18:4] */
+
+ SET_CHAN_REG(chan, LEDC_LSCH0_DUTY_REG, regval << 4);
+
+ /* Start GPIO output */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_SIG_OUT_EN_LSCH0);
+
+ /* Start Duty counter */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF1_REG, LEDC_DUTY_START_LSCH0);
+
+ /* Update duty and phase to hardware */
+
+ SET_CHAN_BITS(chan, LEDC_LSCH0_CONF0_REG, LEDC_PARA_UP_LSCH0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: pwm_setup
+ *
+ * Description:
+ * This method is called when the driver is opened. The lower half driver
+ * should configure and initialize the device so that it is ready for use.
+ * It should not, however, output pulses until the start method is called.
+ *
+ * Input Parameters:
+ * dev - A reference to the lower half PWM driver state structure
+ *
+ * Returned Value:
+ * Zero on success; a negated errno value on failure
+ *
+ ****************************************************************************/
+
+static int pwm_setup(struct pwm_lowerhalf_s *dev)
+{
+ struct esp32_ledc_s *priv = (struct esp32_ledc_s *)dev;
+
+ pwminfo("PWM timer%d\n", priv->num);
+
+ ledc_enable_clk();
+
+ /* Setup channel GPIO pins */
+
+ for (int i = 0; i < priv->channels; i++)
+ {
+ pwminfo("channel%d --> pin%d\n", priv->chans[i].num,
Review comment:
@acassis do you plan to integrate this change?
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