kernel/linux.git/drivers/video/backlight/backlight.c, branch v6.19.11

backlight: Include

2025-09-16T16:05:19+00:00

Include to avoid dependency on backlight header to include it. Signed-off-by: Thomas Zimmermann Reviewed-by: "Daniel Thompson (RISCstar)" Link: https://lore.kernel.org/r/20250715122643.137027-7-tzimmermann@suse.de Signed-off-by: Lee Jones

backlight: Replace fb events with a dedicated function call

2025-04-10T09:39:03+00:00

Remove support for fb events from backlight subsystem. Provide the helper backlight_notify_blank_all() instead. Also export the existing helper backlight_notify_blank() to update a single backlight device. In fbdev, call either helper to inform the backlight subsystem of changes to a display's blank state. If the framebuffer device has a specific backlight, only update this one; otherwise update all. v4: - protect blacklight declarations with IS_REACHABLE() (kernel test robot) v3: - declare empty fb_bl_notify_blank() as static inline (kernel test robot) Signed-off-by: Thomas Zimmermann Acked-by: Simona Vetter Reviewed-by: "Daniel Thompson (RISCstar)" Link: https://lore.kernel.org/r/20250321095517.313713-7-tzimmermann@suse.de Signed-off-by: Lee Jones

backlight: Move blank-state handling into helper

2025-04-10T09:39:01+00:00

Move the handling of blank-state updates into a separate helper, so that is can be called without the fbdev event. No functional changes. As a minor improvement over the original code, the update replaces manual locking with a guard. Signed-off-by: Thomas Zimmermann Reviewed-by: "Daniel Thompson (RISCstar)" Acked-by: Simona Vetter Link: https://lore.kernel.org/r/20250321095517.313713-6-tzimmermann@suse.de Signed-off-by: Lee Jones

backlight: Implement fbdev tracking with blank state from event

2025-04-10T09:39:00+00:00

Look at the blank state provided by FB_EVENT_BLANK to determine whether to enable or disable a backlight. Remove the tracking fields from struct backlight_device. Tracking requires three variables, fb_on, prev_fb_on and the backlight's use_count. If fb_on is true, the display has been unblanked. The backlight needs to be enabled if the display was blanked before (i.e., prev_fb_on is false) or if use_count is still at 0. If fb_on is false, the display has been blanked. In this case, the backlight has to be disabled was unblanked before and the backlight's use_count is greater than 0. This change removes fbdev state tracking from blacklight. All the backlight requires it its own use counter and information about changes to the display. Removing fbdev internals makes backlight drivers easier to integrate into other display drivers, such as DRM. Signed-off-by: Thomas Zimmermann Reviewed-by: "Daniel Thompson (RISCstar)" Acked-by: Simona Vetter Link: https://lore.kernel.org/r/20250321095517.313713-5-tzimmermann@suse.de Signed-off-by: Lee Jones

backlight: Remove notifier

2024-10-09T14:42:48+00:00

backlight_register_notifier and backlight_unregister_notifier have been unused since commit 6cb634d0dc85 ("ACPI: video: Remove code to unregister acpi_video backlight when a native backlight registers") With those not being called, it means that the backlight_notifier list is always empty. Remove the functions, the list itself and the enum used in the notifications. Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Daniel Thompson Reviewed-by: Simona Vetter Link: https://lore.kernel.org/r/20240919232758.639925-1-linux@treblig.org Signed-off-by: Lee Jones

backlight: Make backlight_class constant

2024-05-10T14:44:28+00:00

Since commit 43a7206b0963 ("driver core: class: make class_register() take a const *"), the driver core allows for struct class to be in read-only memory, so move the backlight_class structure to be declared at build time placing it into read-only memory, instead of having to be dynamically allocated at boot time. Cc: Greg Kroah-Hartman Suggested-by: Greg Kroah-Hartman Signed-off-by: Ricardo B. Marliere Reviewed-by: Daniel Thompson Link: https://lore.kernel.org/r/20240305-class_cleanup-backlight-v1-1-c0e15cc25be1@marliere.net Signed-off-by: Lee Jones

Merge branches 'ib-backlight-auxdisplay-staging-omap-6.9', 'ib-backlight-auxdisplay-hid-fb-6.9' and 'ib-backlight-hid-fbdev-lcd-scripts-6.10' into ibs-for-backlight-merged

2024-05-10T14:43:31+00:00

backlight: Remove fb_blank from struct backlight_properties

2024-03-28T10:16:26+00:00

Remove the field fb_blank from struct backlight_properties and remove all code that still sets or reads it. Backlight blank status is now tracked exclusively in struct backlight_properties.state. The core backlight code keeps the fb_blank and state fields in sync, but doesn't do anything else with fb_blank. Several drivers initialize fb_blank to FB_BLANK_UNBLANK to enable the backlight. This is already the default for the state field. So we can delete the fb_blank code from core and drivers and rely on the state field. Signed-off-by: Thomas Zimmermann Cc: Flavio Suligoi Cc: Nicolas Ferre Cc: Alexandre Belloni Cc: Claudiu Beznea Tested-by: Flavio Suligoi Reviewed-by: Daniel Thompson Reviewed-by: Dan Carpenter Link: https://lore.kernel.org/r/20240319093915.31778-7-tzimmermann@suse.de Signed-off-by: Lee Jones

backlight: Add controls_device callback to struct backlight_ops

2024-03-28T10:09:06+00:00

Replace check_fb with controls_device in struct backlight_ops. The new callback interface takes a Linux device instead of a framebuffer. Resolves one of the dependencies of backlight.h on fb.h. The few drivers that had custom implementations of check_fb can easily use the framebuffer's Linux device instead. Update them accordingly. Signed-off-by: Thomas Zimmermann Reviewed-by: Daniel Thompson Reviewed-by: Javier Martinez Canillas Link: https://lore.kernel.org/r/20240305162425.23845-11-tzimmermann@suse.de Signed-off-by: Lee Jones

backlight: Match backlight device against struct fb_info.bl_dev

2024-03-28T10:08:47+00:00

Framebuffer drivers for devices with dedicated backlight are supposed to set struct fb_info.bl_dev to the backlight's respective device. Use the value to match backlight and framebuffer in the backlight core code. The code first tests against struct backlight_ops.check_ops. If this test succeeds, it performs the test against fbdev. So backlight drivers can override the later test as before. Fbdev's backlight support depends on CONFIG_FB_BACKLIGHT. To avoid ifdef in the code, the new helper fb_bl_device() returns the backlight device, or NULL if the config option has been disabled. The test in the backlight code will then do nothing. v4: * declare empty fb_bl_device() as static inline * export fb_bl_device() v3: * hide ifdef in fb_bl_device() (Lee) * no if-else blocks (Andy) Signed-off-by: Thomas Zimmermann Reviewed-by: Daniel Thompson Reviewed-by: Javier Martinez Canillas Link: https://lore.kernel.org/r/20240305162425.23845-2-tzimmermann@suse.de Signed-off-by: Lee Jones