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

[Alexander Dahl <ada@thorsis.com>]

Hello Sven,

Am Tue, Feb 08, 2022 at 08:12:35PM +0100 schrieb sven@svenschwermer.de:
> From: Sven Schwermer <sven.schwermer@disruptive-technologies.com>
> 
> This allows to group multiple PWM-connected monochrome LEDs into
> multicolor LEDs, e.g. RGB LEDs.
> 
> Signed-off-by: Sven Schwermer <sven.schwermer@disruptive-technologies.com>
> ---
> 
> Notes:
>     Changes in v6:
>     * Fix device tree binding schema
>     
>     Changes in v5:
>     * (no changes)
>     
>     Changes in v4:
>     * (no changes)
>     
>     Changes in v3:
>     * Remove multi-led unit name
> 
>  .../bindings/leds/leds-pwm-multicolor.yaml    | 69 +++++++++++++++++++
>  1 file changed, 69 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/leds/leds-pwm-multicolor.yaml
> 
> diff --git a/Documentation/devicetree/bindings/leds/leds-pwm-multicolor.yaml b/Documentation/devicetree/bindings/leds/leds-pwm-multicolor.yaml
> new file mode 100644
> index 000000000000..f7ce29c8ae63
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/leds-pwm-multicolor.yaml
> @@ -0,0 +1,69 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/leds/leds-pwm-multicolor.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Multi-color LEDs connected to PWM
> +
> +maintainers:
> +  - Sven Schwermer <sven.schwermer@disruptive-technologies.com>
> +
> +description: |
> +  This driver combines several monochrome PWM LEDs into one multi-color
> +  LED using the multicolor LED class.
> +
> +properties:
> +  compatible:
> +    const: pwm-leds-multicolor
> +  multi-led:
> +    type: object
> +    patternProperties:
> +      "^led-[0-9a-z]+$":
> +        type: object
> +        $ref: common.yaml#
> +        properties:
> +          pwms:
> +            maxItems: 1
> +          pwm-names: true
> +          color: true
> +        required:
> +          - pwms
> +          - color
> +        additionalProperties: false
> +required:
> +  - compatible
> +allOf:
> +  - $ref: leds-class-multicolor.yaml#
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/leds/common.h>
> +
> +    rgb-led {

I think this should be 'led-controller'. See
Documentation/devicetree/bindings/leds/common.yaml for reference.

> +        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>;
> +          };

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.

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?

Greets
Alex

> +        };
> +    };
> +
> +...
> -- 
> 2.35.1
>