ioexpander/gpio:Add gpio_pin_register_byname

drivers/ioexpander/gpio.c

@@ -546,14 +546,57 @@ static int gpio_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
  *   Register GPIO pin device driver at /dev/gpioN, where N is the provided
  *   minor number.
  *
+ * Input Parameters:
+ *   dev    - A pointer to a gpio_dev_s
+ *   minor  - An integer value to be concatenated with '/dev/gpio'
+ *            to form the device name.
+ *
+ * Returned Value:
+ *   Zero on success; A negated errno value is returned on a failure
+ *   all error values returned by inode_reserve:
+ *
+ *   EINVAL - 'path' is invalid for this operation
+ *   EEXIST - An inode already exists at 'path'
+ *   ENOMEM - Failed to allocate in-memory resources for the operation
+ *
  ****************************************************************************/
 
 int gpio_pin_register(FAR struct gpio_dev_s *dev, int minor)
+{
+  char devname[32];
+
+  snprintf(devname, sizeof(devname), "gpio%u", (unsigned int)minor);
+  return gpio_pin_register_byname(dev, devname);
+}
+
+/****************************************************************************
+ * Name: gpio_pin_register_byname
+ *
+ * Description:
+ *   Register GPIO pin device driver with it's pin name.
+ *
+ * Input Parameters:
+ *   dev      - A pointer to a gpio_dev_s
+ *   pinname  - A pointer to the name to be concatenated with '/dev/'
+ *              to form the device name.
+ *
+ * Returned Value:
+ *   Zero on success; A negated errno value is returned on a failure
+ *   all error values returned by inode_reserve:
+ *
+ *   EINVAL - 'path' is invalid for this operation
+ *   EEXIST - An inode already exists at 'path'
+ *   ENOMEM - Failed to allocate in-memory resources for the operation
+ *
+ ****************************************************************************/
+
+int gpio_pin_register_byname(FAR struct gpio_dev_s *dev,
+                             FAR const char *pinname)
 {
   char devname[32];
   int ret;
 
-  DEBUGASSERT(dev != NULL && dev->gp_ops != NULL);
+  DEBUGASSERT(dev != NULL && dev->gp_ops != NULL && pinname != NULL);
 
   switch (dev->gp_pintype)
     {
@@ -590,7 +633,8 @@ int gpio_pin_register(FAR struct gpio_dev_s *dev, int minor)
         break;
     }
 
-  snprintf(devname, sizeof(devname), "/dev/gpio%u", (unsigned int)minor);
+  snprintf(devname, sizeof(devname), "/dev/%s", pinname);
+
   gpioinfo("Registering %s\n", devname);
 
   return register_driver(devname, &g_gpio_drvrops, 0666, dev);
@@ -603,13 +647,54 @@ int gpio_pin_register(FAR struct gpio_dev_s *dev, int minor)
  *   Unregister GPIO pin device driver at /dev/gpioN, where N is the provided
  *   minor number.
  *
+ * Input Parameters:
+ *   dev    - A pointer to a gpio_dev_s
+ *   minor  - An integer value to be concatenated with '/dev/gpio'
+ *            to form the device name.
+ *
+ * Returned Value:
+ *   Zero on success; A negated value is returned on a failure
+ *   (all error values returned by inode_remove):
+ *
+ *   ENOENT - path does not exist.
+ *   EBUSY  - Ref count is not 0;
+ *
  ****************************************************************************/
 
 int gpio_pin_unregister(FAR struct gpio_dev_s *dev, int minor)
 {
   char devname[32];
+  snprintf(devname, sizeof(devname), "gpio%u", (unsigned int)minor);
+  return gpio_pin_unregister_byname(dev, devname);
+}
+
+/****************************************************************************
+ * Name: gpio_pin_unregister_byname
+ *
+ * Description:
+ *   Unregister GPIO pin device driver at /dev/pinname.
+ *
+ * Input Parameters:
+ *   dev      - A pointer to a gpio_dev_s
+ *   pinname  - A pointer to the name to be concatenated with '/dev/'
+ *              to form the device name.
+ *
+ *
+ * Returned Value:
+ *   Zero on success; A negated value is returned on a failure
+ *   (all error values returned by inode_remove):
+ *
+ *   ENOENT - path does not exist.
+ *   EBUSY  - Ref count is not 0;
+ ****************************************************************************/
+
+int gpio_pin_unregister_byname(FAR struct gpio_dev_s *dev,
+                               FAR const char *pinname)
+{
+  char devname[32];
+
+  snprintf(devname, sizeof(devname), "/dev/%s", pinname);
 
-  snprintf(devname, sizeof(devname), "/dev/gpio%u", (unsigned int)minor);
   gpioinfo("Unregistering %s\n", devname);
 
   return unregister_driver(devname);

include/nuttx/ioexpander/gpio.h

@@ -184,10 +184,47 @@ extern "C"
  *   Register GPIO pin device driver at /dev/gpioN, where N is the provided
  *   minor number.
  *
+ * Input Parameters:
+ *   dev    - A pointer to a gpio_dev_s
+ *   minor  - An integer value to be concatenated with '/dev/gpio'
+ *            to form the device name.
+ *
+ * Returned Value:
+ *   Zero on success; A negated errno value is returned on a failure
+ *   all error values returned by inode_reserve:
+ *
+ *   EINVAL - 'path' is invalid for this operation
+ *   EEXIST - An inode already exists at 'path'
+ *   ENOMEM - Failed to allocate in-memory resources for the operation
+ *
  ****************************************************************************/
 
 int gpio_pin_register(FAR struct gpio_dev_s *dev, int minor);
 
+/****************************************************************************
+ * Name: gpio_pin_register_byname
+ *
+ * Description:
+ *   Register GPIO pin device driver with it's pin name.
+ *
+ * Input Parameters:
+ *   dev      - A pointer to a gpio_dev_s
+ *   pinname  - A pointer to the name to be concatenated with '/dev/'
+ *              to form the device name.
+ *
+ * Returned Value:
+ *   Zero on success; A negated errno value is returned on a failure
+ *   all error values returned by inode_reserve:
+ *
+ *   EINVAL - 'path' is invalid for this operation
+ *   EEXIST - An inode already exists at 'path'
+ *   ENOMEM - Failed to allocate in-memory resources for the operation
+ *
+ ****************************************************************************/
+
+int gpio_pin_register_byname(FAR struct gpio_dev_s *dev,
+                             FAR const char *pinname);
+
 /****************************************************************************
  * Name: gpio_pin_unregister
  *
@@ -195,10 +232,45 @@ int gpio_pin_register(FAR struct gpio_dev_s *dev, int minor);
  *   Unregister GPIO pin device driver at /dev/gpioN, where N is the provided
  *   minor number.
  *
+ * Input Parameters:
+ *   dev    - A pointer to a gpio_dev_s
+ *   minor  - An integer value to be concatenated with '/dev/gpio'
+ *            to form the device name.
+ *
+ * Returned Value:
+ *   Zero on success; A negated value is returned on a failure
+ *   (all error values returned by inode_remove):
+ *
+ *   ENOENT - path does not exist.
+ *   EBUSY  - Ref count is not 0;
+ *
  ****************************************************************************/
 
 int gpio_pin_unregister(FAR struct gpio_dev_s *dev, int minor);
 
+/****************************************************************************
+ * Name: gpio_pin_unregister_byname
+ *
+ * Description:
+ *   Unregister GPIO pin device driver at /dev/pinname.
+ *
+ * Input Parameters:
+ *   dev      - A pointer to a gpio_dev_s
+ *   pinname  - A pointer to the name to be concatenated with '/dev/'
+ *              to form the device name.
+ *
+ *
+ * Returned Value:
+ *   Zero on success; A negated value is returned on a failure
+ *   (all error values returned by inode_remove):
+ *
+ *   ENOENT - path does not exist.
+ *   EBUSY  - Ref count is not 0;
+ ****************************************************************************/
+
+int gpio_pin_unregister_byname(FAR struct gpio_dev_s *dev,
+                               FAR const char *pinname);
+
 /****************************************************************************
  * Name: gpio_lower_half
  *