Re: [PATCH] dt-bindings: leds: Allow differently named multicolor leds

["J. Neuschäfer" <j.ne@posteo.net>]

On Tue, Feb 11, 2025 at 02:43:00PM +0000, Lee Jones wrote:
> On Sun, 09 Feb 2025, J. Neuschäfer via B4 Relay wrote:
> 
> > From: "J. Neuschäfer" <j.ne@posteo.net>
> > 
> > In some cases, a board may have multiple multi-leds, which can't be
> > distinguished by unit address. In such cases it should be possible to
> > name them differently, for example multi-led-a and multi-led-b.
> > This patch adds another node name pattern to leds-class-multicolor.yaml
> > to allow such names.
> 
> Which H/W needs this?  Is it upstream?  Where is the doc / usage?

I encountered this situation while upstreaming the LANCOM NWAPP2 board,
which has multiple LED-group-based multicolor LEDs:

  https://lore.kernel.org/lkml/20250102-mpc83xx-v1-16-86f78ba2a7af@posteo.net/

Since they are based on leds-group-multicolor, they don't have a unit
address, but there is more than one on the same level (as direct
sub-nodes of the DT root node).

I can add a comment about node names, if that's desired, e.g.:

  If multiple multi-color LEDs exist on the same level, they can be
  differentiated by unit-address (e.g. multi-led@abc0) or name
  (e.g. multi-led-power).

Such as a comment doesn't exist currently either; the existing
"^multi-led(@[0-9a-f])?$" pattern is not documented in prose.


Best regards,
J. Neuschäfer


> 
> > Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
> > ---
> >  Documentation/devicetree/bindings/leds/leds-class-multicolor.yaml | 4 +++-
[...]
> > +      - pattern: "^multi-led(@[0-9a-f])?$"
> > +      - pattern: "^multi-led-.*$"