Commit Graph

3 Commits

Author SHA1 Message Date
Thomas Zimmermann
7e3711eb87 fbdev: Track display blanking state
Store the display's blank status in struct fb_info.blank and track
it in fb_blank(). As an extra, the status is now available from the
sysfs blank attribute.

Support for blanking is optional. Therefore framebuffer_alloc()
initializes the state to FB_BLANK_UNBLANK (i.e., the display is
on). If the fb_blank callback has been set, register_framebuffer()
sets the state to FB_BLANK_POWERDOWN. On the first modeset, the
call to fb_blank() will update it to _UNBLANK. This is important,
as listeners to FB_EVENT_BLANK will now see the display being
switched on.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Simona Vetter <simona.vetter@ffwll.ch>
Link: https://lore.kernel.org/r/20250321095517.313713-3-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>
2025-04-10 10:38:57 +01:00
Thomas Zimmermann
c07e1f20dc fbdev: Document that framebuffer_alloc() returns zero'ed data
Most fbdev drivers depend on framebuffer_alloc() to initialize the
allocated memory to 0. Document this guarantee.

v3:
	* slightly reword the sentence (Miguel)

Suggested-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Sui Jingfeng <suijingfeng@loongson.cn>
Cc: Helge Deller <deller@gmx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230715185343.7193-19-tzimmermann@suse.de
2023-07-24 16:50:39 +02:00
Thomas Zimmermann
f0f6839be4 fbdev/core: Move framebuffer and backlight helpers into separate files
Move framebuffer and backlight helpers into separate files. Leave
fbsysfs.c to sysfs-related code. No functional changes.

The framebuffer helpers are not in fbmem.c because they are under
GPL-2.0-or-later copyright, while fbmem.c is GPL-2.0.

v2:
	* include <linux/mutex.h> (Sam)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230613110953.24176-34-tzimmermann@suse.de
2023-06-27 09:58:51 +02:00