Re: [PATCH] input: Add new keyboard backlight control keys to match modern notebooks

[Werner Sembach]

Am 30.05.23 um 13:05 schrieb Werner Sembach:
> The old three KEY_KBDILLUM* keycodes don't reflect the current situation
> modern notebooks anymore. Especially the ones with RGB keyboards.
>
> e.g.
> - Clevo NL50NU has a toggle, an up, a down and a color-cycle key
> - TongFang PH4ARX1 doesn't have a toggle key, but one that cycles through
>    off, half-brightness, and full-brightness.
>
> Also, on some devices these keys are already implemented in firmware. It
> would still be nice if there is a way to let userspace know when one of
> these keys is pressed to display the OSD, but don't advice it to actually
> do anything. This is the intended purpose of the KEY_KBDILLUMCHANGE define.
Nevermind the KEY_KBDILLUMCHANGE. I just found out there is already a way to 
communicate this from kernel to userspace via sysfs 
https://docs.kernel.org/leds/leds-class.html#led-registration-api -> 
brightness_hw_changed
> Signed-off-by: Werner Sembach <wse@xxxxxxxxxxxxxxxxxxx>
> ---
>   include/uapi/linux/input-event-codes.h | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/include/uapi/linux/input-event-codes.h b/include/uapi/linux/input-event-codes.h
> index 022a520e31fc2..05287bf9a77f7 100644
> --- a/include/uapi/linux/input-event-codes.h
> +++ b/include/uapi/linux/input-event-codes.h
> @@ -803,6 +803,10 @@
>   #define BTN_TRIGGER_HAPPY39		0x2e6
>   #define BTN_TRIGGER_HAPPY40		0x2e7
>   
> +#define KEY_KBDILLUMCYCLE		0x2e8
> +#define KEY_KBDILLUMCOLORCYCLE		0x2e9
> +#define KEY_KBDILLUMCHANGE		0x2ea
> +
>   /* We avoid low common keys in module aliases so they don't get huge. */
>   #define KEY_MIN_INTERESTING	KEY_MUTE
>   #define KEY_MAX			0x2ff