gpio: of: Improve kerneldoc

Add descriptions for missing fields and fix up some parameter references
to match the code.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 8cde02e..bfcd206 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -273,14 +273,13 @@
 }
 
 /**
- * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags
+ * of_gpio_simple_xlate - translate gpiospec to the GPIO number and flags
  * @gc:		pointer to the gpio_chip structure
- * @np:		device node of the GPIO chip
- * @gpio_spec:	gpio specifier as found in the device tree
+ * @gpiospec:	GPIO specifier as found in the device tree
  * @flags:	a flags pointer to fill in
  *
  * This is simple translation function, suitable for the most 1:1 mapped
- * gpio chips. This function performs only one sanity check: whether gpio
+ * GPIO chips. This function performs only one sanity check: whether GPIO
  * is less than ngpios (that is specified in the gpio_chip).
  */
 int of_gpio_simple_xlate(struct gpio_chip *gc,
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index ad4150d..fe66c93 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -180,8 +180,27 @@
 	 * If CONFIG_OF is enabled, then all GPIO controllers described in the
 	 * device tree automatically may have an OF translation
 	 */
+
+	/**
+	 * @of_node:
+	 *
+	 * Pointer to a device tree node representing this GPIO controller.
+	 */
 	struct device_node *of_node;
+
+	/**
+	 * @of_gpio_n_cells:
+	 *
+	 * Number of cells used to form the GPIO specifier.
+	 */
 	int of_gpio_n_cells;
+
+	/**
+	 * @of_xlate:
+	 *
+	 * Callback to translate a device tree GPIO specifier into a chip-
+	 * relative GPIO number and flags.
+	 */
 	int (*of_xlate)(struct gpio_chip *gc,
 			const struct of_phandle_args *gpiospec, u32 *flags);
 #endif