backlight: backlight: Improve backlight_ops documentation (ca7c20b2) · Commits · 戴 / test

include/linux/backlight.h

+53 −6

Original line number	Diff line number	Diff line
		@@ -55,19 +55,66 @@ enum backlight_scale {
		struct backlight_device;
		struct fb_info;

		/**
		* struct backlight_ops - backlight operations
		*
		* The backlight operations are specified when the backlight device is registered.
		*/
		struct backlight_ops {
		/**
		* @options: Configure how operations are called from the core.
		*
		* The options parameter is used to adjust the behaviour of the core.
		* Set BL_CORE_SUSPENDRESUME to get the update_status() operation called
		* upon suspend and resume.
		*/
		unsigned int options;

		#define BL_CORE_SUSPENDRESUME (1 << 0)

		/* Notify the backlight driver some property has changed */
		/**
		* @update_status: Operation called when properties have changed.
		*
		* Notify the backlight driver some property has changed.
		* The update_status operation is protected by the update_lock.
		*
		* The backlight driver is expected to use backlight_is_blank()
		* to check if the display is blanked and set brightness accordingly.
		* update_status() is called when any of the properties has changed.
		*
		* RETURNS:
		*
		* 0 on success, negative error code if any failure occurred.
		*/
		int (update_status)(struct backlight_device );
		/* Return the current backlight brightness (accounting for power,
		fb_blank etc.) */

		/**
		* @get_brightness: Return the current backlight brightness.
		*
		* The driver may implement this as a readback from the HW.
		* This operation is optional and if not present then the current
		* brightness property value is used.
		*
		* RETURNS:
		*
		* A brightness value which is 0 or a positive number.
		* On failure a negative error code is returned.
		*/
		int (get_brightness)(struct backlight_device );
		/* Check if given framebuffer device is the one bound to this backlight;
		return 0 if not, !=0 if it is. If NULL, backlight always matches the fb. */
		int (check_fb)(struct backlight_device , struct fb_info *);

		/**
		* @check_fb: Check the framebuffer device.
		*
		* Check if given framebuffer device is the one bound to this backlight.
		* This operation is optional and if not implemented it is assumed that the
		* fbdev is always the one bound to the backlight.
		*
		* RETURNS:
		*
		* If info is NULL or the info matches the fbdev bound to the backlight return true.
		* If info does not match the fbdev bound to the backlight return false.
		*/
		int (check_fb)(struct backlight_device bd, struct fb_info *info);
		};

		/* This structure defines all the properties of a backlight */

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