Re: [PATCH v6 2/3] dt-bindings: leds: Add multicolor PWM LED bindings

[Sven Schwermer <sven@xxxxxxxxxxxxxxxx>]

Hi Alex,

On 2/9/22 10:17, Alexander Dahl wrote:
> > +    rgb-led {
>
> I think this should be 'led-controller'. See
> Documentation/devicetree/bindings/leds/common.yaml for reference.

Sure, I don't have a preference.

> > +        multi-led {
> > +          color = <LED_COLOR_ID_RGB>;
> > +          function = LED_FUNCTION_INDICATOR;
> > +          max-brightness = <65535>;
> > +
> > +          led-red {
> > +              pwms = <&pwm1 0 1000000>;
> > +              color = <LED_COLOR_ID_RED>;
> > +          };
> > +
> > +          led-green {
> > +              pwms = <&pwm2 0 1000000>;
> > +              color = <LED_COLOR_ID_GREEN>;
> > +          };
> > +
> > +          led-blue {
> > +              pwms = <&pwm3 0 1000000>;
> > +              color = <LED_COLOR_ID_BLUE>;
> > +          };
>
> Not sure if those node names should be more generic like led-0, led-1
> etc.?  At least the color information is redundant here.  This would
> make it more similar to bindings of other LED drivers.

I don't see how naming them led-{0,1,2} would be better in any way, 
please elaborate.

> And how is it supposed to be named if you have multiple
> "multi-led"s, e.g. one on three PWM channels, and another one on three
> different PWM channels?

I'm not 100% sure what you mean. If you want multiple instances of these 
multi-color PWM LEDs, you'd do something like this:

indicator-led-controller {
    compatible = "pwm-leds-multicolor";
    multi-led {
      color = <LED_COLOR_ID_RGB>;
      function = LED_FUNCTION_INDICATOR;
      max-brightness = <65535>;
      led-red {
          pwms = <&pwm1 0 1000000>;
          color = <LED_COLOR_ID_RED>;
      };
      led-green {
          pwms = <&pwm2 0 1000000>;
          color = <LED_COLOR_ID_GREEN>;
      };
      led-blue {
          pwms = <&pwm3 0 1000000>;
          color = <LED_COLOR_ID_BLUE>;
      };
    };
};
status-led-controller {
    compatible = "pwm-leds-multicolor";
    multi-led {
      color = <LED_COLOR_ID_MULTI>;
      function = LED_FUNCTION_STATUS;
      max-brightness = <255>;
      led-red {
          pwms = <&pwm4 0 1000000>;
          color = <LED_COLOR_ID_RED>;
      };
      led-amber {
          pwms = <&pwm5 0 1000000>;
          color = <LED_COLOR_ID_AMBER>;
      };
    };
};