[GitHub] kasjer commented on a change in pull request #1575: hw/bus: Add I2C bus driver for nRF52xxx TWIM (DMA)

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kasjer commented on a change in pull request #1575: hw/bus: Add I2C bus driver for nRF52xxx TWIM (DMA)
URL: https://github.com/apache/mynewt-core/pull/1575#discussion_r246342800
 
 

 ##########
 File path: hw/bus/drivers/i2c_nrf52_twim/src/i2c_nrf52_twim.c
 ##########
 @@ -0,0 +1,659 @@
+/*
+ * 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.
+ */
+
+#include <assert.h>
+#include "defs/error.h"
+#include "hal/hal_gpio.h"
+#include "bus/bus.h"
+#include "bus/bus_debug.h"
+#include "bus/bus_driver.h"
+#include "bus/drivers/i2c_common.h"
+#include "mcu/nrf52_hal.h"
+#include "nrfx.h"
+
+#define TWIM_GPIO_PIN_CNF \
+    ((GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos) |  \
+     (GPIO_PIN_CNF_DRIVE_S0D1 << GPIO_PIN_CNF_DRIVE_Pos) |      \
+     (GPIO_PIN_CNF_PULL_Pullup << GPIO_PIN_CNF_PULL_Pos) |      \
+     (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos) |   \
+     (GPIO_PIN_CNF_DIR_Input << GPIO_PIN_CNF_DIR_Pos))
+
+#if MYNEWT_VAL(I2C_NRF52_TWIM_STAT)
+STATS_SECT_START(twim_stats_section)
+    STATS_SECT_ENTRY(sda_lo_err)        /* SDA pulled low on r/w */
+    STATS_SECT_ENTRY(sda_lo_err_nrecov) /* SDA pulled low on r/w (not recovered)*/
+    STATS_SECT_ENTRY(scl_hi_err)        /* SCL unresponsive */
+    STATS_SECT_ENTRY(scl_hi_err_nrecov) /* SCL unresponsive (not recovered)*/
+STATS_SECT_END
+
+STATS_NAME_START(twim_stats_section)
+    STATS_NAME(twim_stats_section, sda_lo_err)
+    STATS_NAME(twim_stats_section, sda_lo_err_nrecov)
+    STATS_NAME(twim_stats_section, scl_hi_err)
+    STATS_NAME(twim_stats_section, scl_hi_err_nrecov)
+STATS_NAME_END(twim_stats_section)
+#endif
+
+struct twim {
+    NRF_TWIM_Type *nrf_twim;
+    int irqn;
+    void (* isr)(void);
+};
+
+static void twim0_irq_handler(void);
+static void twim1_irq_handler(void);
+
+static const struct twim twims[TWIM_COUNT] = {
+    {
+        .nrf_twim = NRF_TWIM0,
+        .irqn = SPIM0_SPIS0_TWIM0_TWIS0_SPI0_TWI0_IRQn,
+        .isr = twim0_irq_handler,
+    },
+    {
+        .nrf_twim = NRF_TWIM1,
+        .irqn = SPIM1_SPIS1_TWIM1_TWIS1_SPI1_TWI1_IRQn,
+        .isr = twim1_irq_handler,
+    },
+};
+
+struct twim_dev_data {
+    struct os_sem sem;
+    uint32_t errorsrc;
+    bool suspended;
+
+#if MYNEWT_VAL(I2C_NRF52_TWIM_STAT)
+    STATS_SECT_DECL(twim_stats_section) stats;
+#endif
+};
+
+static struct bus_i2c_dev *twim_devs[TWIM_COUNT];
+static struct twim_dev_data twim_devs_data[TWIM_COUNT];
+
+static void
+twim_irq_handler(struct bus_i2c_dev *dev)
+{
+    NRF_TWIM_Type *nrf_twim = twims[dev->cfg.i2c_num].nrf_twim;
+    struct twim_dev_data *dd = &twim_devs_data[dev->cfg.i2c_num];
+
+    nrf_twim->INTEN = 0;
+
+    if (nrf_twim->EVENTS_STOPPED) {
+        nrf_twim->EVENTS_STOPPED = 0;
+    }
+
+    if (nrf_twim->EVENTS_SUSPENDED) {
+        nrf_twim->EVENTS_SUSPENDED = 0;
+    }
+
+    if (nrf_twim->EVENTS_ERROR) {
+        nrf_twim->EVENTS_ERROR = 0;
+    }
+
+    dd->errorsrc = nrf_twim->ERRORSRC;
+    nrf_twim->ERRORSRC = dd->errorsrc;
+
+    os_sem_release(&twim_devs_data[dev->cfg.i2c_num].sem);
 
 Review comment:
   dd could be used instead of array access

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