Re: [PATCH RFC leds-next] leds: initial support for Turris Omnia LEDs

Jacek Anaszewski
2020-03-28T13:01:53Z

Hi Marek,

On 3/28/20 1:36 PM, Marek Behun wrote:
>> This was only RFC, please do not merge.
>
> Jacek, Pavel,
>
> I decided to abandon the microcontroller driver path.
> But nonetheless there is still one thing I would like to solve.
>
> The front button on Omnia is used to control the global brightness of
> the RGB LEDs, so that user can change it if the LEDs glow too much.
> The microcontroller does this as such: there is another PWM on top of
> all the LED PWMs, and this value can be manipulated via the same i2c
> interface as the LEDs, but via another command.
>
> The thing is that I would like to somehow export this global brightness
> setting to userspace, because otherwise it gets reset after reboot, and
> I want the user to be able to set this global brightness by software,
> so that they won't have to change it after every reboot manually by
> pressing the front button.
>
> I am wondering how to do this. Last year I proposed this by adding a
> sysfs attribute file to the device which is parent to the LEDs, but you
> did not agree :(

I already proposed adding a "luma" LED class device for similar
case [0], but didn't here any feedback from Pavel so far.

[0]
https://lore.kernel.org/linux-leds/1583502010-16210-1-git-send-email-nbelin@baylibre.com/T/#mf52c8d4f68260a445223c26957c61e6267e0932d

--
Best regards,
Jacek Anaszewski