Commit e389240a authored by Jean-Jacques Hiblot's avatar Jean-Jacques Hiblot Committed by Pavel
Browse files

leds: Add managed API to get a LED from a device driver 



If the LED is acquired by a consumer device with devm_led_get(), it is
automatically released when the device is detached.

Signed-off-by: default avatarJean-Jacques Hiblot <jjhiblot@ti.com>
Acked-by: default avatarPavel Machek <pavel@ucw.cz>
Signed-off-by: default avatarPavel Machek <pavel@ucw.cz>
parent 699a8c7c

drivers/leds/led-class.c

+49 −0
Original line number Diff line number Diff line
@@ -258,6 +258,55 @@ void led_put(struct led_classdev *led_cdev) 
}

EXPORT_SYMBOL_GPL(led_put);



static void devm_led_release(struct device *dev, void *res)

{

	struct led_classdev **p = res;



	led_put(*p);

}



/**

 * devm_of_led_get - Resource-managed request of a LED device

 * @dev:	LED consumer

 * @index:	index of the LED to obtain in the consumer

 *

 * The device node of the device is parse to find the request LED device.

 * The LED device returned from this function is automatically released

 * on driver detach.

 *

 * @return a pointer to a LED device or ERR_PTR(errno) on failure.

 */

struct led_classdev *__must_check devm_of_led_get(struct device *dev,

						  int index)

{

	struct led_classdev *led;

	struct led_classdev **dr;



	if (!dev)

		return ERR_PTR(-EINVAL);



	/* Not using device tree? */

	if (!IS_ENABLED(CONFIG_OF) || !dev->of_node)

		return ERR_PTR(-ENOTSUPP);



	led = of_led_get(dev->of_node, index);

	if (IS_ERR(led))

		return led;



	dr = devres_alloc(devm_led_release, sizeof(struct led_classdev *),

			  GFP_KERNEL);

	if (!dr) {

		led_put(led);

		return ERR_PTR(-ENOMEM);

	}



	*dr = led;

	devres_add(dev, dr);



	return led;

}

EXPORT_SYMBOL_GPL(devm_of_led_get);



static int led_classdev_next_name(const char *init_name, char *name,

				  size_t len)

{

include/linux/leds.h

+2 −0
Original line number Diff line number Diff line
@@ -199,6 +199,8 @@ void led_classdev_resume(struct led_classdev *led_cdev); 


extern struct led_classdev *of_led_get(struct device_node *np, int index);

extern void led_put(struct led_classdev *led_cdev);

struct led_classdev *__must_check devm_of_led_get(struct device *dev,

						  int index);



/**

 * led_blink_set - set blinking with software fallback