2c97d3e55b
Add support for the WMI methods used to turn off and adjust the brightness of the secondary "screenpad" device found on some high-end ASUS laptops like the GX650P series and others. There are some small quirks with this device when considering only the raw WMI methods: 1. The Off method can only switch the device off 2. Changing the brightness turns the device back on 3. To turn the device back on the brightness must be > 1 4. When the device is off the brightness can't be changed (so it is stored by the driver if device is off). 5. Booting with a value of 0 brightness (retained by bios) means the bios will set a value of >0 <15 6. When the device is off it is "unplugged" asus_wmi sets the minimum brightness as 20 in general use, and 60 for booting with values <= min. The ACPI methods are used in a new backlight device named asus_screenpad. Signed-off-by: Luke D. Jones <luke@ljones.dev> Link: https://lore.kernel.org/r/20230830032237.42987-2-luke@ljones.dev Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
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 Restructured Text 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.