gpio/xilinx: Fix kernel-doc

Some documentation were not following the kernel-doc format.
Backporting patch from Xilinx git repository.

Suggested-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-xilinx.c

@@ -40,11 +40,11 @@
 
 /**
  * struct xgpio_instance - Stores information about GPIO device
- * struct of_mm_gpio_chip mmchip: OF GPIO chip for memory mapped banks
- * gpio_state: GPIO state shadow register
- * gpio_dir: GPIO direction shadow register
- * gpio_lock: Lock used for synchronization
- * inited: True if the port has been inited
+ * @mmchip: OF GPIO chip for memory mapped banks
+ * @gpio_state: GPIO state shadow register
+ * @gpio_dir: GPIO direction shadow register
+ * @gpio_lock: Lock used for synchronization
+ * @inited: True if the port has been inited
  */
 struct xgpio_instance {
 	struct of_mm_gpio_chip mmchip;
@@ -63,8 +63,11 @@ struct xgpio {
  * @gc:     Pointer to gpio_chip device structure.
  * @gpio:   GPIO signal number.
  *
- * This function reads the specified signal of the GPIO device. It returns 0 if
- * the signal clear, 1 if signal is set or negative value on error.
+ * This function reads the specified signal of the GPIO device.
+ *
+ * Return:
+ * 0 if direction of GPIO signals is set as input otherwise it
+ * returns negative error value.
  */
 static int xgpio_get(struct gpio_chip *gc, unsigned int gpio)
 {
@@ -107,9 +110,9 @@ static void xgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
  * @gc:     Pointer to gpio_chip device structure.
  * @gpio:   GPIO signal number.
  *
- * This function sets the direction of specified GPIO signal as input.
- * It returns 0 if direction of GPIO signals is set as input otherwise it
- * returns negative error value.
+ * Return:
+ * 0 - if direction of GPIO signals is set as input
+ * otherwise it returns negative error value.
  */
 static int xgpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
 {
@@ -135,8 +138,10 @@ static int xgpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
  * @gpio:   GPIO signal number.
  * @val:    Value to be written to specified signal.
  *
- * This function sets the direction of specified GPIO signal as output. If all
- * GPIO signals of GPIO chip is configured as input then it returns
+ * This function sets the direction of specified GPIO signal as output.
+ *
+ * Return:
+ * If all GPIO signals of GPIO chip is configured as input then it returns
  * error otherwise it returns 0.
  */
 static int xgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
@@ -166,7 +171,7 @@ static int xgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
 
 /**
  * xgpio_save_regs - Set initial values of GPIO pins
- * @mm_gc: pointer to memory mapped GPIO chip structure
+ * @mm_gc: Pointer to memory mapped GPIO chip structure
  */
 static void xgpio_save_regs(struct of_mm_gpio_chip *mm_gc)
 {
@@ -207,9 +212,9 @@ static int xgpio_remove(struct platform_device *pdev)
  * xgpio_of_probe - Probe method for the GPIO device.
  * @pdev: pointer to the platform device
  *
- * This function probes the GPIO device in the device tree. It initializes the
- * driver data structure. It returns 0, if the driver is bound to the GPIO
- * device, or a negative value if there is an error.
+ * Return:
+ * It returns 0, if the driver is bound to the GPIO device, or
+ * a negative value if there is an error.
  */
 static int xgpio_probe(struct platform_device *pdev)
 {