Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit c2adda27 authored by Meghana Madhyastha's avatar Meghana Madhyastha Committed by Sean Paul
Browse files

video: backlight: Add of_find_backlight helper in backlight.c 



Add of_find_backlight, a helper function which is a generic version
of tinydrm_of_find_backlight that can be used by other drivers to avoid
repetition of code and simplify things.

Acked-by: default avatarDaniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: default avatarNoralf Trønnes <noralf@tronnes.org>
Reviewed-by: default avatarSean Paul <seanpaul@chromium.org>
Reviewed-by: default avatarThierry Reding <treding@nvidia.com>
Signed-off-by: default avatarMeghana Madhyastha <meghana.madhyastha@gmail.com>
Signed-off-by: default avatarSean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/116d160ba78be2e6dcbdcb6855622bce67da9472.1516810725.git.meghana.madhyastha@gmail.com
parent 5b698be0

drivers/video/backlight/backlight.c

+43 −0
Original line number Diff line number Diff line
@@ -580,6 +580,49 @@ struct backlight_device *of_find_backlight_by_node(struct device_node *node) 
EXPORT_SYMBOL(of_find_backlight_by_node);

#endif



/**

 * of_find_backlight - Get backlight device

 * @dev: Device

 *

 * This function looks for a property named 'backlight' on the DT node

 * connected to @dev and looks up the backlight device.

 *

 * Call backlight_put() to drop the reference on the backlight device.

 *

 * Returns:

 * A pointer to the backlight device if found.

 * Error pointer -EPROBE_DEFER if the DT property is set, but no backlight

 * device is found.

 * NULL if there's no backlight property.

 */

struct backlight_device *of_find_backlight(struct device *dev)

{

	struct backlight_device *bd = NULL;

	struct device_node *np;



	if (!dev)

		return NULL;



	if (IS_ENABLED(CONFIG_OF) && dev->of_node) {

		np = of_parse_phandle(dev->of_node, "backlight", 0);

		if (np) {

			bd = of_find_backlight_by_node(np);

			of_node_put(np);

			if (!bd)

				return ERR_PTR(-EPROBE_DEFER);

			/*

			 * Note: gpio_backlight uses brightness as

			 * power state during probe

			 */

			if (!bd->props.brightness)

				bd->props.brightness = bd->props.max_brightness;

		}

	}



	return bd;

}

EXPORT_SYMBOL(of_find_backlight);



static void __exit backlight_class_exit(void)

{

	class_destroy(backlight_class);

include/linux/backlight.h

+19 −0
Original line number Diff line number Diff line
@@ -162,6 +162,16 @@ static inline int backlight_disable(struct backlight_device *bd) 
	return backlight_update_status(bd);

}



/**

 * backlight_put - Drop backlight reference

 * @bd: the backlight device to put

 */

static inline void backlight_put(struct backlight_device *bd)

{

	if (bd)

		put_device(&bd->dev);

}



extern struct backlight_device *backlight_device_register(const char *name,

	struct device *dev, void *devdata, const struct backlight_ops *ops,

	const struct backlight_properties *props);
@@ -205,4 +215,13 @@ of_find_backlight_by_node(struct device_node *node) 
}

#endif



#if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE)

struct backlight_device *of_find_backlight(struct device *dev);

#else

static inline struct backlight_device *of_find_backlight(struct device *dev)

{

	return NULL;

}

#endif



#endif