[RESPONDED] Controlling the keyboard backlight through /sys

Hi, I was looking into setting the keyboard backlight brightness automatically with brightnessctl but it doesn’t look like the LED is recognized by Linux. The arch wiki page on the subject says the LED should be available under /sys/class/leds, but I can only see the *lock keys LEDs, this is what I get:


I’m not sure what phy0-led is, but I tried setting it on and off and it doesn’t affect the keyboard backlights.

Is there some kernel setting I can turn on to get the keyboard backlight to show up on /sys or is it not implemented?

The question I have to ask is this - this is under Arch or Ubuntu, Fedora, or?

Right now, the keyboard backlight is handled entirely by the embedded controller. It’s not accessible via sysfs, since there is no driver that enumerates LEDs hanging off the EC.

I’ve been (slowly :frowning_face:) working on a driver that exposes the backlight via the LED subsystem and the charge limit via a battery hook. While it works, it’s not really “production-quality” and not ready to be submitted upstream to the kernel.


@DHowett is this something that you could make public while still working on it?