Re: [PATCH] dt-bindings: display: panel: use spi-peripheral-props.yaml

[Krzysztof Kozlowski]

On 04/10/2022 15:17, Laurent Pinchart wrote:
> Hi Krzysztof,
> 
> On Tue, Oct 04, 2022 at 03:10:29PM +0200, Krzysztof Kozlowski wrote:
>> On 04/10/2022 15:03, Laurent Pinchart wrote:
>>> On Tue, Oct 04, 2022 at 02:09:07PM +0200, Krzysztof Kozlowski wrote:
>>>> For devices connectable by SPI bus (e.g. already using
>>>> "spi-max-frequency" property), reference the "spi-peripheral-props.yaml"
>>>> schema to allow using all SPI device properties, even these which device
>>>> bindings author did not tried yet.
>>>
>>> Isn't this done implicitly by spi-controller.yaml ? SPI devices that are
>>> children of an SPI controller should match the patternProperties
>>> "^.*@[0-9a-f]+$" in that file, which has a $ref: spi-peripheral-props.yaml.
>>> Is there something I'm missing ?
>>
>> You are correct about one side of this - SPI controller bindings.
>> However these schemas here have clear: additional/unevaluatedProperties:
>> false, thus when they find DTS like:
>> panel@xxx {
>>   compatible = "one of these spi panels";
>>   ...
>>   spi-cs-high;
>>   spi-rx-delay-us = <50>;
>>   ... and some more from specific controllers
>> }
>>
>> you will get errors, because the panel schema does not allow them.
>>
>> The bindings were done (some time ago) in such way, that they require
>> that both SPI controller and SPI device reference spi-props.
> 
> You're absolutely right that additionalProperties needs to be replaced
> by unevaluatedProperties. Can the additions of $ref be dropped, or is
> that needed too ?

I just wrote above  - you need to reference the spi-props. Otherwise all
the SPI-related properties will be unknown/unevaluated.

Best regards,
Krzysztof