Re: Proposal: Add color_temperature support

[Pavel Machek <pavel@ucw.cz>]

[-- Attachment #1: Type: text/plain, Size: 1461 bytes --]

Hi!

> > > On the device Logitech Litra Glow it is possible to set not only the
> > > brightness but also the color temperature (both via usb as well as via
> > > hardware).
> > > I am currently trying to add support for the device - and expose it
> > > via LED - into the kernel.
> > > So to support all device capabilities I am proposing to extend LEDs by
> > > color temperature:
> > > And initial patch for the headers:
> >
> > Internally, the litra glow is something like RGB LED, right? Can we
> > support it as a multicolor LED?
> The litra glow has 2 control dimensions - brightness and color temperature.
> Both dimensions can be controlled in something of a continuous range
> (not sure whether these are strictly linear or not).
> Thus mapping to RGB would look like more of a very sparse array.
> Also, not sure which exact RGB value you would map a color temperature
> to anyway.
> So at first glance supporting it as a multicolor LED does not seem a
> good match to me.

Hmm, and there are likely to be more lights like this, right? OTOH it
is not really an indicator LED -- using capslock trigger makes little
sense with this one.

I guess it makes sense to support this in LED subsystem. I believe it
should be only supported for "white" LEDs. I believe first step is
defining an userspace API in Documentation.

Best regards,
								Pavel
-- 
People of Russia, stop Putin before his war on Ukraine escalates.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 195 bytes --]