a1cacb8a8e
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>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.