Re: [PATCH v4 3/7] dt-bindings: leds: Add virtual LED group controller bindings

["Rob Herring (Arm)" <robh@kernel.org>]

On Tue, 30 Dec 2025 13:32:40 +1300, Jonathan Brophy wrote:
> From: Jonathan Brophy <professor_jonny@hotmail.com>
> 
> Add device tree bindings for the virtual LED group controller that
> provides priority-based arbitration for shared physical LEDs across
> multiple virtual LED instances.
> 
> Bindings for the virtual driver are not describing hardware LEDs they
> describe virtual devices made from groups of hardware LEDs created from an array
> of LED phandles.
> 
> Normally the device tree is used to describe hardware not virtual hardware
> but it is particularly useful in situations where you require an LED to be a
> specific color by mixing primary colors, such as multi element multi color LEDs
> to be operated from a device tree binding or a single trigger.
> 
> It also becomes useful with multiple LEDs operating the same indicator such as
> ring of light indicators, led rope where the LEDs are driven From different GPIO
> outputs unifying the control that can give basic indication during system startup,
> shutdown upgrade etc...
> The controller implements winner-takes-all arbitration where only the
> highest-priority active virtual LED controls the hardware at any given
> time. This enables multiple subsystems (boot, error, status indicators)
> to request LED control without explicit coordination.
> 
> Binding supports:
> - Multiple virtual LED children with independent priorities
> - GPIO, PWM, I2C, and SPI physical LED devices
> - Multicolor and standard (fixed-color) operating modes
> - Global ownership tracking to prevent conflicts
> 
> Example configurations include:
> - High-priority emergency/error RGB indicator
> - Medium-priority system state RGBW indicator
> - Low-priority warm white fixed-color indicator
> 
> Co-developed-by: Radoslav Tsvetkov <rtsvetkov@gradotech.eu>
> Signed-off-by: Radoslav Tsvetkov <rtsvetkov@gradotech.eu>
> Signed-off-by: Jonathan Brophy <professor_jonny@hotmail.com>
> ---
>  .../leds/leds-group-virtualcolor.yaml         | 170 ++++++++++++++++++
>  1 file changed, 170 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/leds/leds-group-virtualcolor.yaml
> 

My bot found errors running 'make dt_binding_check' on your patch:

yamllint warnings/errors:

dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/leds/leds-group-virtualcolor.example.dtb: pwm-led-controller (pwm-leds): 'led-pwm-blue', 'led-pwm-green', 'led-pwm-red' do not match any of the regexes: '^led(-[0-9a-f]+)?$', '^pinctrl-[0-9]+$'
	from schema $id: http://devicetree.org/schemas/leds/leds-pwm.yaml

doc reference errors (make refcheckdocs):

See https://patchwork.kernel.org/project/devicetree/patch/20251230003250.1197744-4-professorjonny98@gmail.com

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.