On Fri, 12 Mar 2021 04:48:52 +0000
Hermes Zhang <[email protected]> wrote:
> >
> > Sorry, leds-regulator has only a binary state LED.
> >
> > Maybe you could extend leds-regulator to be able to use all regulator
> > states?
> >
> > Or you can extend leds-gpio driver to support N states via log N gpios,
> > instead of adding new driver.
>
> It seems a good idea to extend leds-gpio, so in my case, I should have such
> dts:
>
> 63 leds {
> 64 compatible = "gpio-leds";
> 65
> 66 recording_front {
> 67 label = "recording_front:red";
> 68 gpios = <&gpio 130 GPIO_ACTIVE_HIGH>, <&gpio 129
> GPIO_ACTIVE_HIGH>;
> 69 default-state = "off";
> 70 };
> 71 };
>
> For my case, two leds is enough, but it sill easy to extend the support
> number bigger than two. And the length of gpios array is not fixed, so it
> could compatible with exist "gpio-leds" dts, right?
>
> If this idea work, should I create a new commit or still in this track (V2)?
However you want :)
Look at the states property of gpio regulator:
https://www.kernel.org/doc/Documentation/devicetree/bindings/regulator/gpio-regulator.yaml
It is possible to have a multi-GPIO LED which brightness is set via N
GPIOs and it has 2^N brightness states encoded by binary values of
those GPIOs, but it is entirely possible to have less than 2^N states,
or that the states are encoded in a different way.
In the first version though imlpemenent just the simplest case: N GPIOs
with 2^N states.
Marek
