Re: [PATCH v4 2/3] dt-bindings: leds: add worldsemi,ws2812b

Krzysztof Kozlowski
2022-12-12T08:57:05Z

On 12/12/2022 05:55, Chuanhong Guo wrote:
> Add dt binding schema for WorldSemi WS2812B driven using SPI
> bus.
>
> Signed-off-by: Chuanhong Guo <gch981213@gmail.com>
> ---
> Changes since v1:
> remove linux driver reference from description
> remove some obvious descriptions
> fix unit address regex in multi-led property
> drop various minItems
> add maxItems = 1 to reg
> fix node names and property orders in binding example
> drop -spi from compatible string
> add default-brightness
>
> Change since v2:
> drop "this patch" from commit message
> rename leds to led-controller
> drop default-brightness and default-intensity
>
> Change since v3:
> reword commit title
>
> .../bindings/leds/worldsemi,ws2812b.yaml | 116 ++++++++++++++++++
> 1 file changed, 116 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/leds/worldsemi,ws2812b.yaml
>
> diff --git a/Documentation/devicetree/bindings/leds/worldsemi,ws2812b.yaml b/Documentation/devicetree/bindings/leds/worldsemi,ws2812b.yaml
> new file mode 100644
> index 000000000000..548c05ac3d31
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/worldsemi,ws2812b.yaml
> @@ -0,0 +1,116 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/leds/worldsemi,ws2812b.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: WS2812B LEDs driven using SPI
> +
> +maintainers:
> + - Chuanhong Guo <gch981213@gmail.com>
> +
> +description: |
> + WorldSemi WS2812B is a individually addressable LED chip that can be chained
> + together and controlled individually using a single wire.
> + This binding describes a chain of WS2812B LEDs connected to the SPI MOSI pin.
> + Typical setups includes connecting the data pin of the LED chain to MOSI as
> + the only device or using CS and MOSI with a tri-state voltage-level shifter
> + for the data pin.
> + The SPI frequency needs to be 2.105MHz~2.85MHz for the timing to be correct
> + and the controller needs to send all the bytes continuously.
> +
> +allOf:
> + - $ref: /schemas/spi/spi-peripheral-props.yaml#
> +
> +properties:
> + compatible:
> + const: worldsemi,ws2812b
> +
> + reg:
> + maxItems: 1
> +
> + spi-max-frequency:
> + minimum: 2105000
> + maximum: 2850000
> +
> + "#address-cells":
> + const: 1
> +
> + "#size-cells":
> + const: 0
> +
> +patternProperties:
> + "^multi-led@[0-9a-f]+$":
> + type: object
> + $ref: leds-class-multicolor.yaml#
> + unevaluatedProperties: false
> +
> + properties:
> + color-index:
> + description: |
> + A 3-item array specifying color of each components in this LED. It
> + should be one of the LED_COLOR_ID_* prefixed definitions from the
> + header include/dt-bindings/leds/common.h. Defaults to
> + <LED_COLOR_ID_GREEN LED_COLOR_ID_RED LED_COLOR_ID_BLUE>
> + if unspecified.
> + $ref: /schemas/types.yaml#/definitions/uint32-array
> + maxItems: 3

In general I am fine with it, although there is still question for
adding more multi-color defines in binding headers to replace this
property - GRB/RBG/GBR and even more for RGBW.

Pavel, Lee, any thoughts from your side?

Best regards,
Krzysztof