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>
diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index c6fd580..4efda31 100644
--- a/drivers/gpio/gpio-uclass.c
+++ b/drivers/gpio/gpio-uclass.c
@@ -127,7 +127,7 @@
 	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;
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index b1cf95c..0af599f 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -434,6 +434,18 @@
 			      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
  *
  * Counts the GPIOs in a list. See gpio_request_by_name() for additional