Re: [PATCH v3 1/6] dt-bindings: arm: qcom: Document qcs8550 SoC and board

[Krzysztof Kozlowski <krzk@kernel.org>]

On 19/12/2023 10:45, Aiqun Yu (Maria) wrote:
>>> +      - items:
>>> +          - enum:
>>> +              - qcom,qcs8550-aim300-aiot
>>> +          - const: qcom,qcs8550-aim300
>>> +          - const: qcom,qcs8550
> Need to add below line here, right?
> +          - const: qcom,sm8550

Yes.

>>
>> Missing compatible. Please read previous discussions.
> The previous comments was missed. Just double confirm here for 
> "fallback" meaning here.
> 
> Could you pls also double confirm for my understandings for the 
> compatible rules?

Compatible rules were expressed in Devicetree specification and also
writing-bindings document.

> As long as sm8550 was designed "hardware compatible"(pin-to-pin 
> compatible) and "software firmware compatible"(firmware also support 
> sm8550) to qcs8550, it is request to add compatible sm8550 to current 
> compatible sequence like: board/SOM/soc/base soc.

I understood before that firmware is not compatible. Are there any
changes now?

The understanding was that your new SoC is stripped down SM8550, thus
you will be using almost all of the SM8550 DTSI. If you use all of
device nodes, the devices are compatible, aren't they? If they are
compatible, then the writing-bindings document asks you to do add
specific compatible.

Please reach internally within Qualcomm for some initial guidance how
DTS and DTSI looks like, so reviewers on mailing list won't need to
explain it.

This week it is third comment like this on mailing lists for three
different patchsets. It is great that you send code upstream. Big
companies however are expected to do some internal work first, instead
of relying on the community.

> 
> Note that, we don't really have hardware like "sm8550 inside aim300".

I really don't know what do you have and I did not find any explanation
of QCS8550 in this commit msg which brings new compatible.

Best regards,
Krzysztof