Re: [PATCH 3/4] dt-bindings: leds: Add binding for a multicolor group of LEDs

[Jean-Jacques Hiblot]

On 28/06/2022 00:12, Rob Herring wrote:
> On Wed, Jun 15, 2022 at 05:49:17PM +0200, Jean-Jacques Hiblot wrote:
> > This allows to group multiple monochromatic LEDs into a multicolor
> > LED, e.g. RGB LEDs.
> >
> > Signed-off-by: Jean-Jacques Hiblot <jjhiblot@xxxxxxxxxxxxxxx>
> > ---
> >   .../bindings/leds/leds-group-multicolor.yaml  | 94 +++++++++++++++++++
> >   1 file changed, 94 insertions(+)
> >   create mode 100644 Documentation/devicetree/bindings/leds/leds-group-multicolor.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/leds/leds-group-multicolor.yaml b/Documentation/devicetree/bindings/leds/leds-group-multicolor.yaml
> > new file mode 100644
> > index 000000000000..30a67985ae33
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/leds/leds-group-multicolor.yaml
> > @@ -0,0 +1,94 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/leds/leds-group-multicolor.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Multi-color LED built with monochromatic LEDs
> > +
> > +maintainers:
> > +  - Jean-Jacques Hiblot <jjhiblot@xxxxxxxxxxxxxxx>
> > +
> > +description: |
> > +  This driver combines several monochromatic LEDs into one multi-color
> > +  LED using the multicolor LED class.
> > +
> > +properties:
> > +  compatible:
> > +    const: leds-group-multicolor
> > +
> > +  multi-led:
> > +    type: object
> > +
> > +    patternProperties:
> > +      "^led-[0-9a-z]+$":
> > +        type: object
> > +        $ref: common.yaml#
> > +
> > +        additionalProperties: false
> > +
> > +        properties:
> > +          leds:
> Not a standard property. What is the type?
That would be a reference to the node of a LED
> Really, just do a GPIO multi-color LED binding similar to the PWM one
> rather than adding this layer. I suppose you could combine LEDs from all
> different controllers, but that seems somewhat unlikely to me.

I'm not using gpio leds, rather leds driven by two TLC5925.

I agree that combining from different model of controller is unlikely. 
However from 2 separate chips of the same model is not (ex: driving 5 
RGB LEDs with two 8-output chips)

In the case of the TLC5925, that is not really a problem because as long 
as the chips are on the same CS, they are considered as a single entity 
by the driver. But for I2C chips at least that would be a problem.


JJ

> Rob