Messages in this thread | | | Subject | Re: [PATCH v2 2/2] leds: lp50xx: Add the LP50XX family of the RGB LED driver | From | Vesa Jääskeläinen <> | Date | Sun, 20 Jan 2019 08:51:48 +0200 |
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Hi Pavel,
On 19/01/2019 23.46, Pavel Machek wrote: > Hi! > >>> Moreover, I think that RGB LED class with configurable >>> brightness-model, and with possible color range adjustments via >>> icc-profiles or something similar, is the best solution that has been >>> proposed so far. It is just flexible. >>> >>> I'd like to capitalize on the ideas shared in this thread and have >>> finally LED RGB class materialized. >>> >> >> I have now updated my github code with my understanding of the discussion: >> https://github.com/vesajaaskelainen/linux/tree/wip-multi-color-led >> >> Commits: >> - dt-bindings: leds: Introduce linux,default-brightness-model for all leds >> https://github.com/vesajaaskelainen/linux/commit/4ffb21d644056686096226bbede7c8c78b0254c2 >> - drivers: leds: Add core support for multi color element LEDs >> https://github.com/vesajaaskelainen/linux/commit/627f38bb78cebc694b8e6d735fb088c87925435d >> - dt-bindings: leds: leds-pwm: Introduce multi color element leds support >> https://github.com/vesajaaskelainen/linux/commit/ef6c5730d621e79ea0b02470caa83bc39439536a >> - WIP: drivers: leds: leds-pwm: Add multi color element LED support. >> https://github.com/vesajaaskelainen/linux/commit/0430a27823d9162926424b32c23be1c53eb9cbe2 >> >> First two commits are common and could be taken before I am happy with the >> pwm led driver changes. This new conditional feature flag makes it a bit >> harder. Of course one option would be to require it to be enabled. >> >> Current set of concepts: >> - brightness-model: hardware, onoff, linear >> - could be extended in future with other modes like hsv if wanted > > Would it be enough to tell userspace what is relation between values > it writes and output power? > > Onoff is subset of linear, I guess. We already have max_brightness in > the API.
Btw. there is slight problem with led trigger framework which is kinda visible with "onoff" vs "linear" settings.
If you configure color like:
echo onoff > brightness_model echo 32 0 32 255 > color
You get not so bright pink color. And if you then enable blinking:
echo heartbeat > trigger
Then it blinks with not so bright pink color as expected.
However if you do it:
echo linear > brightness_model echo 255 0 255 32 > color
You once again you get not so bright pink color. However when you enable blinking:
echo heartbeat > trigger
Then it blinks with very bright pink color.
Reason I believe is because trigger uses either values 0 or 255 for brightness when controlling. To fix the issue I believe trigger mechanism should be adjusted to allowing one to control ON brightness level.
I would recommend fixing this trigger problem with future patches for it.
Thanks, Vesa Jääskeläinen
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