linux-toradex.git/include/linux/backlight.h, branch v6.16-rc6 Linux kernel for Apalis and Colibri modules backlight: Replace fb events with a dedicated function call 2025-04-10T09:39:03+00:00 Thomas Zimmermann tzimmermann@suse.de 2025-03-21T09:53:59+00:00 b01beb2f1f6bcda17634a5b529865ffc5a9b795f 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 <tzimmermann@suse.de> Acked-by: Simona Vetter <simona.vetter@ffwll.ch> Reviewed-by: "Daniel Thompson (RISCstar)" <danielt@kernel.org> Link: https://lore.kernel.org/r/20250321095517.313713-7-tzimmermann@suse.de Signed-off-by: Lee Jones <lee@kernel.org> 
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 <tzimmermann@suse.de>
Acked-by: Simona Vetter <simona.vetter@ffwll.ch>
Reviewed-by: "Daniel Thompson (RISCstar)" <danielt@kernel.org>
Link: https://lore.kernel.org/r/20250321095517.313713-7-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>
backlight: Implement fbdev tracking with blank state from event 2025-04-10T09:39:00+00:00 Thomas Zimmermann tzimmermann@suse.de 2025-03-21T09:53:57+00:00 726491f2038ec71122d45700f3abf36fdb277aaa 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 <tzimmermann@suse.de> Reviewed-by: "Daniel Thompson (RISCstar)" <danielt@kernel.org> Acked-by: Simona Vetter <simona.vetter@ffwll.ch> Link: https://lore.kernel.org/r/20250321095517.313713-5-tzimmermann@suse.de Signed-off-by: Lee Jones <lee@kernel.org> 
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 <tzimmermann@suse.de>
Reviewed-by: "Daniel Thompson (RISCstar)" <danielt@kernel.org>
Acked-by: Simona Vetter <simona.vetter@ffwll.ch>
Link: https://lore.kernel.org/r/20250321095517.313713-5-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>
backlight: Remove notifier 2024-10-09T14:42:48+00:00 Dr. David Alan Gilbert linux@treblig.org 2024-09-19T23:27:58+00:00 5461f3fd74a89757f95f351eb0bc26aafc2a2e91 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 <linux@treblig.org> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Reviewed-by: Simona Vetter <simona.vetter@ffwll.ch> Link: https://lore.kernel.org/r/20240919232758.639925-1-linux@treblig.org Signed-off-by: Lee Jones <lee@kernel.org> 
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 <linux@treblig.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Simona Vetter <simona.vetter@ffwll.ch>
Link: https://lore.kernel.org/r/20240919232758.639925-1-linux@treblig.org
Signed-off-by: Lee Jones <lee@kernel.org>
backlight: Add BACKLIGHT_POWER_ constants for power states 2024-07-04T15:45:25+00:00 Thomas Zimmermann tzimmermann@suse.de 2024-06-24T15:19:56+00:00 a1cacb8a8e70c38ec0c78910c668abda99fcb780 Duplicate FB_BLANK_ constants as BACKLIGHT_POWER__ constants in the backlight header file. Allows backlight drivers to avoid including the fbdev header file and removes a compile-time dependency between the two subsystems. The new BACKLIGHT_POWER_ constants have the same values as their FB_BLANK_ counterparts. Hence UAPI and internal semantics do not change. The backlight drivers can be converted one by one. Each instance of FB_BLANK_UNBLANK becomes BACKLIGHT_POWER_ON, each of FB_BLANK_POWERDOWN becomes BACKLIGHT_POWER_OFF, and FB_BLANK_NORMAL becomes BACKLIGHT_POWER_REDUCED. Backlight code or drivers do not use FB_BLANK_VSYNC_SUSPEND and FB_BLANK_HSYNC_SUSPEND, so no new constants for these are being added. The semantics of FB_BLANK_NORMAL appear inconsistent. In fbdev, NORMAL means display off with sync enabled. In backlight code, this translates to turn the backlight off, but some drivers interpret it as backlight on. So we keep the current code as is, but mark BACKLIGHT_POWER_REDUCED as deprecated. Drivers should be fixed and the constant removed. This affects ams369fg06 and a few DRM panel drivers. v2: - rename BL_CORE_ power constants to BACKLIGHT_POWER_ (Sam) - fix documentation Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Link: https://lore.kernel.org/r/20240624152033.25016-2-tzimmermann@suse.de Signed-off-by: Lee Jones <lee@kernel.org> 
Duplicate FB_BLANK_ constants as BACKLIGHT_POWER__ constants in the
backlight header file. Allows backlight drivers to avoid including
the fbdev header file and removes a compile-time dependency between
the two subsystems.

The new BACKLIGHT_POWER_ constants have the same values as their
FB_BLANK_ counterparts. Hence UAPI and internal semantics do not
change. The backlight drivers can be converted one by one. Each
instance of FB_BLANK_UNBLANK becomes BACKLIGHT_POWER_ON, each of
FB_BLANK_POWERDOWN becomes BACKLIGHT_POWER_OFF, and FB_BLANK_NORMAL
becomes BACKLIGHT_POWER_REDUCED.

Backlight code or drivers do not use FB_BLANK_VSYNC_SUSPEND and
FB_BLANK_HSYNC_SUSPEND, so no new constants for these are being
added.

The semantics of FB_BLANK_NORMAL appear inconsistent. In fbdev,
NORMAL means display off with sync enabled. In backlight code,
this translates to turn the backlight off, but some drivers
interpret it as backlight on. So we keep the current code as is,
but mark BACKLIGHT_POWER_REDUCED as deprecated. Drivers should be
fixed and the constant removed. This affects ams369fg06 and a few
DRM panel drivers.

v2:
- rename BL_CORE_ power constants to BACKLIGHT_POWER_ (Sam)
- fix documentation

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20240624152033.25016-2-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>
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 Lee Jones lee@kernel.org 2024-05-10T14:43:31+00:00 13cb61bed54d12cd67450ad4612ce0978f9329cb 






backlight: Remove fb_blank from struct backlight_properties
2024-03-28T10:16:26+00:00

Thomas Zimmermann
tzimmermann@suse.de

2024-03-19T09:37:25+00:00

4551978bb50a8d59b49629deebacd73478a8b1e1

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 <tzimmermann@suse.de>
Cc: Flavio Suligoi <f.suligoi@asem.it>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Claudiu Beznea <claudiu.beznea@tuxon.dev>
Tested-by: Flavio Suligoi <f.suligoi@asem.it>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/20240319093915.31778-7-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>





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 <tzimmermann@suse.de>
Cc: Flavio Suligoi <f.suligoi@asem.it>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Claudiu Beznea <claudiu.beznea@tuxon.dev>
Tested-by: Flavio Suligoi <f.suligoi@asem.it>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/20240319093915.31778-7-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>







backlight: Add controls_device callback to struct backlight_ops
2024-03-28T10:09:06+00:00

Thomas Zimmermann
tzimmermann@suse.de

2024-03-05T16:22:43+00:00

0a4be7263749945a3882f7a0e2e5b1c45c31064e

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 <tzimmermann@suse.de>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20240305162425.23845-11-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>





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 <tzimmermann@suse.de>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20240305162425.23845-11-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>







backlight: backlight: Make of_find_backlight static
2020-07-20T09:27:11+00:00

Sam Ravnborg
sam@ravnborg.org

2020-07-19T08:07:43+00:00

b6539a11e807c531e51ff7ad9a25c3a1b6ff7340

There are no external users of of_find_backlight, as they have all
changed to use the managed version. Make of_find_backlight static to
prevent new external users.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>





There are no external users of of_find_backlight, as they have all
changed to use the managed version. Make of_find_backlight static to
prevent new external users.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>







backlight: backlight: Drop backlight_put()
2020-07-20T09:27:09+00:00

Sam Ravnborg
sam@ravnborg.org

2020-07-19T08:07:42+00:00

0f6a3256fd810eeca9c56cccafee46359d995138

There are no external users of backlight_put(). Drop it and open code
the two users in backlight.c.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>





There are no external users of backlight_put(). Drop it and open code
the two users in backlight.c.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>







backlight: backlight: Introduce backlight_get_brightness()
2020-07-20T09:27:02+00:00

Sam Ravnborg
sam@ravnborg.org

2020-07-19T08:07:36+00:00

2144d00ed0db28c764513080f95e4c49ea9133b0

Based on an idea from Emil Velikov, add a helper that checks
backlight_is_blank() and return 0 as brightness if display is blank or
the property value if not.

This allows us to simplify the update_status() implementation
in most of the backlight drivers.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>





Based on an idea from Emil Velikov, add a helper that checks
backlight_is_blank() and return 0 as brightness if display is blank or
the property value if not.

This allows us to simplify the update_status() implementation
in most of the backlight drivers.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>