Re: [PATCH 2/4] dt-bindings: display/msm/gpu: document using the amd,imageon adreno too

[Dmitry Baryshkov <dmitry.baryshkov@linaro.org>]

On 06/07/2022 18:50, Krzysztof Kozlowski wrote:
> On 06/07/2022 16:52, Dmitry Baryshkov wrote:
>> The DT binding desribes using amd,imageon only for Imageon 2xx GPUs. We
>> have been using amd,imageon with newer (Adreno) GPUs to describe the
>> headless setup, when the platform does not (yet) have the display DT
> 
> Does not have "yet"? So later it will have and you drop a compatible?

Yes. For example see the arch/arm64/boot/dts/qcom/8150.dtsi, which 
currently has only GPU node. Once we add MDSS/DPU/DSI/etc. nodes, we are 
going to drop the compat string.

> 
>> nodes (and no display support). Document this trick in the schema.
>>
>> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>> ---
>>   Documentation/devicetree/bindings/display/msm/gpu.yaml | 6 ++++++
>>   1 file changed, 6 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/display/msm/gpu.yaml b/Documentation/devicetree/bindings/display/msm/gpu.yaml
>> index 346aabdccf7b..e006da95462c 100644
>> --- a/Documentation/devicetree/bindings/display/msm/gpu.yaml
>> +++ b/Documentation/devicetree/bindings/display/msm/gpu.yaml
>> @@ -16,9 +16,13 @@ properties:
>>         - description: |
>>             The driver is parsing the compat string for Adreno to
>>             figure out the gpu-id and patch level.
>> +          Optional amd,imageon compatibility string enables using Adreno
>> +          without the display node.
>>           items:
>>             - pattern: '^qcom,adreno-[3-6][0-9][0-9]\.[0-9]$'
>>             - const: qcom,adreno
>> +          - const: amd,imageon
>> +        minItems: 2
> 
> This is too unspecific. You allow any device to be and not to be
> compatible with amd,imageon.

Yes, this is expected (kind of). Would you have any 
alternatives/suggestions?

> 
>>         - description: |
>>             The driver is parsing the compat string for Imageon to
>>             figure out the gpu-id and patch level.
>> @@ -148,6 +152,8 @@ allOf:
>>                   description: GPU 3D engine clock
>>                 - const: rbbmtimer
>>                   description: GPU RBBM Timer for Adreno 5xx series
>> +              - const: rbcpr
>> +                description: GPU RB CPR clock
>>             minItems: 2
>>             maxItems: 7
> 
> Do 8 items work with maxItems:7?

You would have guessed, yes, they do.

-- 
With best wishes
Dmitry