kernel/linux.git/drivers/video/backlight/lcd.c, branch v6.18.22

backlight: lcd: Replace fb events with a dedicated function call

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

Remove support for fb events from the lcd subsystem. Provide the helper lcd_notify_blank_all() instead. In fbdev, call lcd_notify_blank_all() to inform the lcd subsystem of changes to a display's blank state. Fbdev maintains a list of all installed notifiers. Instead of fbdev notifiers, maintain an internal list of lcd devices. v3: - export lcd_notify_mode_change_all() (kernel test robot) v2: - maintain global list of lcd devices - avoid IS_REACHABLE() in source file - use lock guards - initialize lcd list and list mutex Signed-off-by: Thomas Zimmermann Acked-by: Simona Vetter Reviewed-by: "Daniel Thompson (RISCstar)" Link: https://lore.kernel.org/r/20250321095517.313713-9-tzimmermann@suse.de Signed-off-by: Lee Jones

backlight: lcd: Move event handling into helpers

2025-04-10T09:39:09+00:00

Move the handling of display updates to separate helper functions. There is code for handling fbdev blank events and fbdev mode changes. The code currently runs from fbdev event notifiers, which will be replaced. Signed-off-by: Thomas Zimmermann Reviewed-by: "Daniel Thompson (RISCstar)" Acked-by: Simona Vetter Link: https://lore.kernel.org/r/20250321095517.313713-8-tzimmermann@suse.de Signed-off-by: Lee Jones

backlight: lcd: Remove struct fb_videomode from set_mode callback

2024-09-30T15:49:42+00:00

Implementations of struct lcd_ops.set_mode only require the resolution from struct fb_videomode. Pass the xres and yres fields, but remove the dependency on the fbdev data structure. Signed-off-by: Thomas Zimmermann Reviewed-by: Daniel Thompson Link: https://lore.kernel.org/r/20240906075439.98476-28-tzimmermann@suse.de Signed-off-by: Lee Jones

backlight: lcd: Replace check_fb with controls_device

2024-09-30T15:49:42+00:00

Rename check_fb in struct lcd_ops to controls_device. The callback is now independent from fbdev's struct fb_info and tests if an lcd device controls a hardware display device. The new naming and semantics follow similar functionality for backlight devices. v2: - fix typos in commit description (Daniel) Signed-off-by: Thomas Zimmermann Reviewed-by: Daniel Thompson Link: https://lore.kernel.org/r/20240906075439.98476-27-tzimmermann@suse.de Signed-off-by: Lee Jones

backlight: lcd: Add LCD_POWER_ constants for power states

2024-09-30T15:49:41+00:00

Duplicate FB_BLANK_ constants as LCD_POWER_ constants in the lcd header file. Allows lcd drivers to avoid including the fbdev header file and removes a compile-time dependency between the two subsystems. The new LCD_POWER_ constants have the same values as their FB_BLANK_ counterparts. Hence semantics does not change and the lcd drivers can be converted one by one. Each instance of FB_BLANK_UNBLANK becomes LCD_POWER_ON, each of FB_BLANK_POWERDOWN becomes LCD_POWER_OFF, FB_BLANK_NORMAL becomes LCD_POWER_REDUCED and FB_BLANK_VSYNC_SUSPEND becomes LCD_POWER_REDUCED_VSYNC_SUSPEND. Lcd code or drivers do not use FB_BLANK_HSYNC_SUSPEND, so no new constants for this is being added. The tokens LCD_POWER_REDUCED and LCD_POWER_REDUCED_VSYNC_SUSPEND are deprecated and drivers should replace them with LCD_POWER_ON and LCD_POWER_OFF. See also commit a1cacb8a8e70 ("backlight: Add BACKLIGHT_POWER_ constants for power states"), which added similar constants for backlight drivers. v2: - fix typo in commit description Signed-off-by: Thomas Zimmermann Reviewed-by: Daniel Thompson Link: https://lore.kernel.org/r/20240906075439.98476-4-tzimmermann@suse.de Signed-off-by: Lee Jones

backlight: lcd: Test against struct fb_info.lcd_dev

2024-09-30T15:49:41+00:00

Add struct fb_info.lcd_dev for fbdev drivers to store a reference to their lcd device. Update the lcd's fb_notifier_callback() to test for this field. The lcd module can now detect if an lcd device belongs to an fbdev device. This works similar to the bl_dev for backlights and will allow for the removal of the check_fb callback from several fbdev driver's lcd devices. Signed-off-by: Thomas Zimmermann Reviewed-by: Daniel Thompson Link: https://lore.kernel.org/r/20240906075439.98476-3-tzimmermann@suse.de Signed-off-by: Lee Jones

backlight: lcd: Rearrange code in fb_notifier_callback()

2024-09-30T15:49:41+00:00

First acquire the ops_lock and do all tests while holding it. Rearranges the code in lcd's fb_notifier_callback() to resemble the callback in the backlight module. This will simplify later changes to these tests. v2: - avoid gotos by using guard(mutex) (Daniel) - fix typos in commit description (Daniel) Signed-off-by: Thomas Zimmermann Reviewed-by: Daniel Thompson Link: https://lore.kernel.org/r/20240906075439.98476-2-tzimmermann@suse.de Signed-off-by: Lee Jones

backlight: lcd: Make lcd_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 lcd_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 Signed-off-by: Greg Kroah-Hartman Reviewed-by: Daniel Thompson Link: https://lore.kernel.org/r/2024032809-enchanted-conducive-3677@gregkh Signed-off-by: Lee Jones

backlight: lcd: Constify lcd_ops

2024-05-03T09:44:42+00:00

'struct lcd_ops' passed in lcd_device_register() is not modified by core backlight code, so it can be made const for code safety. This allows drivers to also define the structure as const. Signed-off-by: Krzysztof Kozlowski Reviewed-by: Daniel Thompson Link: https://lore.kernel.org/r/20240424-video-backlight-lcd-ops-v2-1-1aaa82b07bc6@kernel.org Signed-off-by: Lee Jones

driver core: class: remove module * from class_create()

2023-03-17T14:16:33+00:00

The module pointer in class_create() never actually did anything, and it shouldn't have been requred to be set as a parameter even if it did something. So just remove it and fix up all callers of the function in the kernel tree at the same time. Cc: "Rafael J. Wysocki" Acked-by: Benjamin Tissoires Link: https://lore.kernel.org/r/20230313181843.1207845-4-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman