Re: [PATCH RFC 1/2] dt-bindings: leds-group-multicolor: Introduce default-intensity

[Stefan Wahren <wahrenst@gmx.net>]

Hi all,

Am 09.07.26 um 20:03 schrieb Conor Dooley:
> On Thu, Jul 09, 2026 at 12:46:51AM +0200, Stefan Wahren wrote:
>> Currently it's not possible to specify the initial color of a LED group
>> during boot. So introduce a new property similar to default-brightness,
>> which specifies the intensity of each LED in the group.
>>
>> Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
>> ---
>>   .../devicetree/bindings/leds/leds-group-multicolor.yaml    | 7 +++++++
>>   1 file changed, 7 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/leds/leds-group-multicolor.yaml b/Documentation/devicetree/bindings/leds/leds-group-multicolor.yaml
>> index 5c9cfa39396b..18b722b807ba 100644
>> --- a/Documentation/devicetree/bindings/leds/leds-group-multicolor.yaml
>> +++ b/Documentation/devicetree/bindings/leds/leds-group-multicolor.yaml
>> @@ -19,6 +19,12 @@ properties:
>>   
>>     leds: true
>>   
>> +  default-intensity:
>> +    description:
>> +      Intensity to be set for each individual LED. Used only during
>> +      initialization. If the property is not set then max intensity is used.
>> +    $ref: /schemas/types.yaml#/definitions/uint32-array
> Hmm, there's already a property proposed and applied for this:
> https://lore.kernel.org/linux-leds/20260605-multicolor-default-v2-1-ed07271df6b0@pengutronix.de/
sorry, I missed this. Thanks for pointing to this patch. In general i'm 
fine with this approach, but there is something which confuses me.
Looking at the description, there is the statement: [default-intensity] 
"Defaults to 0".
This seems to be correct for the Linux implementation of 
leds-pwm-multicolor, but is this really an expectation along all (multi 
color) LEDs (at least for Linux)?

E.g. leds-group-multicolor init the intensity with the maximum. So all 
users of leds-group-multicolor should specify default-intensity for each 
sub LED to achieve a defined behavior without breaking existing behavior.

Best regards

> It only supports a single value, I suspect you'll have to rework this so
> as not to conflict with existing property?
> leds-group-multicolour imports the common leds properties after all.
> Probably the one in common.yaml needs to become an array?
>
>> +
>>   required:
>>     - leds
>>   
>> @@ -56,6 +62,7 @@ examples:
>>           color = <LED_COLOR_ID_RGB>;
>>           function = LED_FUNCTION_INDICATOR;
>>           leds = <&led0>, <&led1>, <&led2>;
>> +        default-intensity = <1 0 0>;
>>       };
>>   
>>   ...
>> -- 
>> 2.43.0
>>