Messages in this thread | | | Date | Mon, 9 Jan 2023 16:52:34 +0000 | From | Lee Jones <> | Subject | Re: [PATCH v4 2/3] dt-bindings: leds: add worldsemi,ws2812b |
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On Sat, 24 Dec 2022, Krzysztof Kozlowski wrote:
> On 23/12/2022 18:19, Pavel Machek wrote: > > Hi! > > > >>> 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:
Why "index"?
Isn't it just an array of colours rather than an index into something?
> >>> + description: | > >>> + A 3-item array specifying color of each components in this LED. It
Why are you forcing this to 3?
Surely there are multi-colour LEDs containing more or less colours?
> >>> + should be one of the LED_COLOR_ID_* prefixed definitions from the > >>> + header include/dt-bindings/leds/common.h. Defaults to
Isn't "include" a Linuxisum?
> >>> + <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? > > > > This really needs to mention the name this hardware is known as -- I > > believe it is NeoPixel. > > We wait here for feedback on colors... The binding is re-implementing > color, just because of combinations GRB/RBG/GBR, which could be achieved > with new color defines.
Sure, but where does that end?
How many permutations are there likely to be?
An unlimited array has more of a chance of standing the test of time.
-- Lee Jones [李琼斯]
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