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

[Chuanhong Guo]

Hi!

On Wed, Nov 30, 2022 at 5:08 PM Krzysztof Kozlowski
<krzysztof.kozlowski@xxxxxxxxxx> wrote:
> And that's exactly what I said - the compatibles should not include bus
> information. The bus information comes from... the bus!

Oh. I thought there will be a conflict if there is a SPI driver and
, say, an I2C driver with the same compatible string.

> [...]
> >>
> >> Why unit address is optional?
> >
> > It isn't. I copy-pasted it from led-class-multicolor.yaml and
> > didn't check the exact regex.
> > I'll fix it in the next version.
>
> Make it required and matching your case.

Got it.

> [...]
> >>> +      default-intensity:
> >>> +        description: |
> >>> +          An array of 3 integer specifying the default intensity of each color
> >>> +          components in this LED. <255 255 255> if unspecified.
> >>> +        $ref: /schemas/types.yaml#/definitions/uint32-array
> >>> +        minItems: 3
> [...]
> So this is brightness of each color...

I don't think so.
See the kernel doc for multicolor LED:
https://docs.kernel.org/leds/leds-class-multicolor.html
This property sets the sysfs file multi_intensity while the
actual LED brightness is controlled with another sysfs
file called 'brightness'.
Setting multi_intensity alone doesn't change the LED
brightness at all.

-- 
Regards,
Chuanhong Guo