dm: gpio: Add dm_gpio_request() to manually request a GPIO

This function can be used for testing to manually request a GPIO for use,
without resorting to the legacy GPIO API.

Signed-off-by: Simon Glass <sjg@chromium.org>

drivers/gpio/gpio-uclass.c

@@ -127,7 +127,7 @@ static int gpio_find_and_xlate(struct gpio_desc *desc,
 	return ops->xlate ? ops->xlate(desc->dev, desc, args) : 0;
 }
 
-static int dm_gpio_request(struct gpio_desc *desc, const char *label)
+int dm_gpio_request(struct gpio_desc *desc, const char *label)
 {
 	struct udevice *dev = desc->dev;
 	struct gpio_dev_priv *uc_priv;

include/asm-generic/gpio.h

@@ -433,6 +433,18 @@ int gpio_request_list_by_name(struct udevice *dev, const char *list_name,
 			      struct gpio_desc *desc_list, int max_count,
 			      int flags);
 
+/**
+ * dm_gpio_request() - manually request a GPIO
+ *
+ * Note: This function should only be used for testing / debugging. Instead.
+ * use gpio_request_by_name() to pull GPIOs from the device tree.
+ *
+ * @desc:	GPIO description of GPIO to request (see dm_gpio_lookup_name())
+ * @label:	Label to attach to the GPIO while claimed
+ * @return 0 if OK, -ve on error
+ */
+int dm_gpio_request(struct gpio_desc *desc, const char *label);
+
 /**
  * gpio_get_list_count() - Returns the number of GPIOs in a list
  *