Re: [PATCH 1/2] dt-bindings: arm-smmu: Document SM61[12]5 GPU SMMU

From: Konrad Dybcio
Date: Thu Mar 16 2023 - 18:00:02 EST




On 16.03.2023 20:29, Krzysztof Kozlowski wrote:
> On 15/03/2023 11:52, Konrad Dybcio wrote:
>> Both of these SoCs have a Qualcomm MMU500 implementation of SMMU
>> in front of their GPUs that expect 3 clocks. Both of them also have
>> an APPS SMMU that expects no clocks. Remove qcom,sm61[12]5-smmu-500
>> from the "no clocks" list (intentionally 'breaking' the schema checks
>> of APPS SMMU, as now it *can* accept clocks - with the current
>> structure of this file it would have taken a wastefully-long time to
>> sort this out properly..) and add necessary yaml to describe the
>> clocks required by the GPU SMMUs.
>
>
>> + properties:
>> + compatible:
>> + items:
>> + - enum:
>> + - qcom,sm6115-smmu-500
>> + - qcom,sm6125-smmu-500
>> + - const: qcom,adreno-smmu
>> + - const: qcom,smmu-500
>> + - const: arm,mmu-500
>
> If you drop the hunk later (from allOf:if), then what clocks do you
> expect for non-GPU SMMU?
Both 6115 and 6125 require no clocks under the APPS (non-GPU) SMMU.
However, the list below uses a `contains:` which means I'd have
to add a whole another hunk like

- items:
- enum:
- qcom,sm6115-smmu-500
- qcom,sm6125-smmu-500
- const: qcom,smmu-500
- const: arm,mmu-500

and add another level of indentation to the previous one

I figured skipping that was less messy (I think we discussed this
once as well), but if you prefer to keep it strict, I can.

Konrad

>
>> + then:
>> + properties:
>> + clock-names:
>> + items:
>> + - const: mem
>> + - const: hlos
>> + - const: iface
>> +
>> + clocks:
>> + items:
>> + - description: GPU memory bus clock
>> + - description: Voter clock required for HLOS SMMU access
>> + - description: Interface clock required for register access
>> +
>> # Disallow clocks for all other platforms with specific compatibles
>> - if:
>> properties:
>> @@ -394,8 +420,6 @@ allOf:
>> - qcom,sdm845-smmu-500
>> - qcom,sdx55-smmu-500
>> - qcom,sdx65-smmu-500
>> - - qcom,sm6115-smmu-500
>> - - qcom,sm6125-smmu-500
>> - qcom,sm6350-smmu-500
>> - qcom,sm6375-smmu-500
>> - qcom,sm8350-smmu-500
>>
>
> Best regards,
> Krzysztof
>