video: backlight: Add of_find_backlight helper in backlight.c (c2adda27) · Commits · 戴 / test

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);

+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