[GitHub] [nuttx] pkarashchenko commented on a diff in pull request #10426: ioexpander: add support for ISO1H812G expander

["pkarashchenko (via GitHub)" <gi...@apache.org>]

pkarashchenko commented on code in PR #10426:
URL: https://github.com/apache/nuttx/pull/10426#discussion_r1307512794


##########
drivers/ioexpander/iso1h812g.c:
##########
@@ -0,0 +1,466 @@
+/****************************************************************************
+ * drivers/ioexpander/iso1h812g.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 <nuttx/config.h>
+
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+#include <sys/param.h>
+
+#include <nuttx/kmalloc.h>
+#include <nuttx/arch.h>
+#include <nuttx/spi/spi.h>
+#include <nuttx/ioexpander/ioexpander.h>
+#include <nuttx/ioexpander/iso1h812g.h>
+
+#include "iso1h812g.h"
+
+#ifdef CONFIG_IOEXPANDER_ISO1H812G
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+struct iso1h812g_dev_s
+{
+  struct ioexpander_dev_s dev;           /* Nested structure to allow casting as public gpio
+                                          * expander. */
+  FAR struct iso1h812g_config_s *config; /* Board configuration data */
+  FAR struct spi_dev_s *spi;             /* Saved SPI driver instance */
+  uint8_t outstate;
+  mutex_t lock;
+};
+
+/****************************************************************************
+ * Private Function Protototypes
+ ****************************************************************************/
+
+/* SPI helpers */
+
+static void iso1h812g_select(FAR struct spi_dev_s *spi,
+                             FAR struct iso1h812g_config_s *config,
+                             int bits);
+static void iso1h812g_deselect(FAR struct spi_dev_s *spi,
+                               FAR struct iso1h812g_config_s *config);
+
+/* I/O Expander Methods */
+
+static int iso1h812g_direction(FAR struct ioexpander_dev_s *dev, uint8_t pin,
+             int dir);
+static int iso1h812g_option(FAR struct ioexpander_dev_s *dev, uint8_t pin,
+             int opt, void *regval);
+static int iso1h812g_writepin(FAR struct ioexpander_dev_s *dev, uint8_t pin,
+             bool value);
+static int iso1h812g_readpin(FAR struct ioexpander_dev_s *dev, uint8_t pin,
+             FAR bool *value);
+#ifdef CONFIG_IOEXPANDER_MULTIPIN
+static int iso1h812g_multiwritepin(FAR struct ioexpander_dev_s *dev,
+             FAR const uint8_t *pins, FAR bool *values, int count);
+static int iso1h812g_multireadpin(FAR struct ioexpander_dev_s *dev,
+             FAR const uint8_t *pins, FAR bool *values, int count);
+#endif
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+#ifndef CONFIG_ISO1H812G_MULTIPLE
+/* If only a single device is supported, then the driver state structure may
+ * as well be pre-allocated.
+ */
+
+static struct iso1h812g_dev_s g_iso1h812g;
+#endif
+
+/* I/O expander vtable */
+
+static const struct ioexpander_ops_s g_iso1h812g_ops =
+{
+  iso1h812g_direction,
+  iso1h812g_option,
+  iso1h812g_writepin,
+  iso1h812g_readpin,
+  iso1h812g_readpin
+#ifdef CONFIG_IOEXPANDER_MULTIPIN
+  , iso1h812g_multiwritepin
+  , iso1h812g_multireadpin
+  , iso1h812g_multireadpin
+#endif
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: iso1h812g_select
+ *
+ * Description:
+ *   Select the SPI, locking and  re-configuring if necessary
+ *
+ * Input Parameters:
+ *   spi   - Reference to the SPI driver structure
+ *   bits  - Number of SPI bits
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+static void iso1h812g_select(FAR struct spi_dev_s *spi,
+                             FAR struct iso1h812g_config_s *config, int bits)
+{
+  /* Select ISO1H812G chip (locking the SPI bus in case there are multiple
+   * devices competing for the SPI bus
+   */
+
+  SPI_LOCK(spi, true);
+  SPI_SELECT(spi, SPIDEV_EXPANDER(config->id), true);
+
+  /* Now make sure that the SPI bus is configured for the ISO1H812G (it
+   * might have gotten configured for a different device while unlocked)
+   */
+
+  SPI_SETMODE(spi, config->mode);
+  SPI_SETBITS(spi, bits);
+  SPI_SETFREQUENCY(spi, config->frequency);
+}
+
+/****************************************************************************
+ * Name: iso1h812g_deselect
+ *
+ * Description:
+ *   De-select the SPI
+ *
+ * Input Parameters:
+ *   spi  - Reference to the SPI driver structure
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+static void iso1h812g_deselect(FAR struct spi_dev_s *spi,
+                               FAR struct iso1h812g_config_s *config)
+{
+  /* De-select ISO1H812G chip and relinquish the SPI bus. */
+
+  SPI_SELECT(spi, SPIDEV_EXPANDER(config->id), false);
+  SPI_LOCK(spi, false);
+}
+
+/****************************************************************************
+ * Name: iso1h812g_direction
+ *
+ * Description:
+ *   ISO1H812G is only input pin. However interface is provided in order
+ *   to avoid system falls if called.
+ *
+ * Input Parameters:
+ *   dev - Device-specific state data
+ *   pin - The index of the pin to alter in this call
+ *   dir - One of the IOEXPANDER_DIRECTION_ macros
+ *
+ * Returned Value:
+ *   0 on success, else a negative error code
+ *
+ ****************************************************************************/
+
+static int iso1h812g_direction(FAR struct ioexpander_dev_s *dev,
+                               uint8_t pin, int direction)
+{
+  FAR struct iso1h812g_dev_s *priv = (FAR struct iso1h812g_dev_s *)dev;
+
+  DEBUGASSERT(priv != NULL && priv->config != NULL);
+
+  gpiowarn("WARNING: ISO1H812G is only input expander!\n");
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: iso1h812g_option
+ *
+ * Description:
+ *   Set pin options. Required.
+ *   Since all IO expanders have various pin options, this API allows setting
+ *     pin options in a flexible way.
+ *
+ * Input Parameters:
+ *   dev - Device-specific state data
+ *   pin - The index of the pin to alter in this call
+ *   opt - One of the IOEXPANDER_OPTION_ macros
+ *   val - The option's value
+ *
+ * Returned Value:
+ *   0 on success, else a negative error code
+ *
+ ****************************************************************************/
+
+static int iso1h812g_option(FAR struct ioexpander_dev_s *dev, uint8_t pin,
+                            int opt, FAR void *value)
+{
+  gpiowarn("WARNING: ISO1H812G does not have options!\n");
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: iso1h812g_writepin
+ *
+ * Description:
+ *   Set the pin level. Required.
+ *
+ * Input Parameters:
+ *   dev - Device-specific state data
+ *   pin - The index of the pin to alter in this call
+ *   val - The pin level. Usually TRUE will set the pin high,
+ *         except if OPTION_INVERT has been set on this pin.
+ *
+ * Returned Value:
+ *   0 on success, else a negative error code
+ *
+ ****************************************************************************/
+
+static int iso1h812g_writepin(FAR struct ioexpander_dev_s *dev, uint8_t pin,
+                              bool value)
+{
+  FAR struct iso1h812g_dev_s *priv = (FAR struct iso1h812g_dev_s *)dev;
+  int ret;
+
+  if (pin > 7)
+    {
+      return -ENXIO;
+    }
+
+  DEBUGASSERT(priv != NULL && priv->config != NULL);
+
+  gpioinfo("Expander id=%02x, pin=%u\n", priv->config->id, pin);
+
+  /* Get exclusive access to the I/O Expander */
+
+  ret = nxmutex_lock(&priv->lock);
+  if (ret < 0)
+    {
+      return ret;
+    }
+
+  /* Set/clear a bit in outstate. */
+
+  if (value)
+    {
+      priv->outstate |= (1 << pin);
+    }
+  else
+    {
+      priv->outstate &= ~(1 << pin);
+    }
+
+  iso1h812g_select(priv->spi, priv->config, 8);
+  SPI_SEND(priv->spi, priv->outstate);
+  iso1h812g_deselect(priv->spi, priv->config);
+
+  nxmutex_unlock(&priv->lock);
+  return ret;
+}
+
+/****************************************************************************
+ * Name: iso1h812g_readpin
+ *
+ * Description:
+ *   Read the actual PIN level. This can be different from the last value
+ *   written to this pin. Required.
+ *
+ * Input Parameters:
+ *   dev    - Device-specific state data
+ *   pin    - The index of the pin
+ *   valptr - Pointer to a buffer where the pin level is stored. Usually TRUE
+ *            if the pin is high, except if OPTION_INVERT has been set on
+ *            this pin.
+ *
+ * Returned Value:
+ *   0 on success, else a negative error code
+ *
+ ****************************************************************************/
+
+static int iso1h812g_readpin(FAR struct ioexpander_dev_s *dev, uint8_t pin,
+                             FAR bool *value)
+{
+  gpiowarn("WARNING: ISO1H812G is only output expander!\n");
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: iso1h812g_multiwritepin
+ *
+ * Description:
+ *   Set the pin level for multiple pins. This routine may be faster than
+ *   individual pin accesses. Optional.
+ *
+ * Input Parameters:
+ *   dev - Device-specific state data
+ *   pins - The list of pin indexes to alter in this call
+ *   val - The list of pin levels.
+ *
+ * Returned Value:
+ *   0 on success, else a negative error code
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_IOEXPANDER_MULTIPIN
+static int iso1h812g_multiwritepin(FAR struct ioexpander_dev_s *dev,
+                                   FAR const uint8_t *pins, FAR bool *values,
+                                   int count)
+{
+  FAR struct iso1h812g_dev_s *priv = (FAR struct iso1h812g_dev_s *)dev;
+  int ret;
+  uint8_t pin;
+  int i;
+
+  DEBUGASSERT(priv != NULL && priv->config != NULL && values != NULL);
+
+  /* Get exclusive access to the I/O Expander */
+
+  ret = nxmutex_lock(&priv->lock);
+  if (ret < 0)
+    {
+      return ret;
+    }
+
+  /* Set/clear a bit in outstate. */
+
+  for (i = 0; i < count; i++)
+    {
+      pin = pins[i];
+      gpioinfo("Expander id=%02x, pin=%u\n", priv->config->id, pin);
+
+      if (pin > 7)
+        {
+          return -ENXIO;
+        }
+
+      if (values[i])
+        {
+          priv->outstate |= (1 << pin);
+        }
+      else
+        {
+          priv->outstate &= ~(1 << pin);
+        }
+    }
+
+  iso1h812g_select(priv->spi, priv->config, 8);
+  SPI_SEND(priv->spi, priv->outstate);
+  iso1h812g_deselect(priv->spi, priv->config);
+
+  nxmutex_unlock(&priv->lock);
+  return ret;
+}
+
+/****************************************************************************
+ * Name: iso1h812g_multireadpin
+ *
+ * Description:
+ *   Read the actual level for multiple pins. This routine may be faster than
+ *   individual pin accesses. Optional.
+ *
+ * Input Parameters:
+ *   dev    - Device-specific state data
+ *   pin    - The list of pin indexes to read
+ *   valptr - Pointer to a buffer where the pin levels are stored.
+ *
+ * Returned Value:
+ *   0 on success, else a negative error code
+ *
+ ****************************************************************************/
+
+static int iso1h812g_multireadpin(FAR struct ioexpander_dev_s *dev,
+                                  FAR const uint8_t *pins, FAR bool *values,
+                                  int count)
+{
+  gpiowarn("WARNING: ISO1H812G is only output expander!\n");
+
+  return OK;
+}
+#endif /* CONFIG_IOEXPANDER_MULTIPIN */
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: iso1h812g_initialize
+ *
+ * Description:
+ *   Instantiate and configure the ISO1H812Gxx device driver to use the
+ *   provided SPI device instance.
+ *
+ * Input Parameters:
+ *   spi     - A SPI driver instance
+ *   config  - Persistent board configuration data
+ *
+ * Returned Value:
+ *   an ioexpander_dev_s instance on success, NULL on failure.
+ *
+ ****************************************************************************/
+
+FAR struct ioexpander_dev_s *iso1h812g_initialize(FAR struct spi_dev_s *spi,
+                                      FAR struct iso1h812g_config_s *config)
+{
+  FAR struct iso1h812g_dev_s *priv;
+
+#ifdef CONFIG_ISO1H812G_MULTIPLE
+  /* Allocate the device state structure */
+
+  priv = (FAR struct iso1h812g_dev_s *)

Review Comment:
   I do not think we need a cast here



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