Re: [PATCH v2 08/20] dt-bindings: serial: samsung: Add google-gs101-uart compatible

[Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>]

On 11/10/2023 10:57, Greg KH wrote:
> On Wed, Oct 11, 2023 at 09:49:07AM +0100, Tudor Ambarus wrote:
>> Hi, Greg,
>>
>> On 10/11/23 08:48, Greg KH wrote:
>>> On Tue, Oct 10, 2023 at 11:49:16PM +0100, Peter Griffin wrote:
>>>> Add dedicated google-gs101-uart compatible to the dt-schema for
>>>> representing uart of the Google Tensor gs101 SoC.
>>>>
>>>> Signed-off-by: Peter Griffin <peter.griffin@xxxxxxxxxx>
>>>> ---
>>>>  Documentation/devicetree/bindings/serial/samsung_uart.yaml | 2 ++
>>>>  1 file changed, 2 insertions(+)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/serial/samsung_uart.yaml b/Documentation/devicetree/bindings/serial/samsung_uart.yaml
>>>> index 8bd88d5cbb11..72471ebe5734 100644
>>>> --- a/Documentation/devicetree/bindings/serial/samsung_uart.yaml
>>>> +++ b/Documentation/devicetree/bindings/serial/samsung_uart.yaml
>>>> @@ -19,11 +19,13 @@ properties:
>>>>    compatible:
>>>>      oneOf:
>>>>        - items:
>>>> +          - const: google,gs101-uart
>>>>            - const: samsung,exynosautov9-uart
>>>>            - const: samsung,exynos850-uart
>>>>        - enum:
>>>>            - apple,s5l-uart
>>>>            - axis,artpec8-uart
>>>> +          - google,gs101-uart
>>>
>>> These shouldn't be needed, just declare the device as the same as what
>>
>> We should have SoC specific compatibles so that any further quirks or
>> incompatibilities can be easily addressed.
> 
> "further" work on quirks or incompatibilities can be added when they are
> found and needed.  We don't add stuff for no good reason to the kernel.

With a Devicetree bindings maintainer hat:
We expect the device-specific compatible in all bindings, followed by
fallback. The fallback is used by the driver, the device-specific for
any future needs.

This is the practice we follow everywhere and recommend everywhere since
some time. It is also documented here:

https://elixir.bootlin.com/linux/v6.6-rc5/source/Documentation/devicetree/bindings/writing-bindings.rst#L42

Best regards,
Krzysztof