Re: [PATCH v2 1/3] dt-bindings: clock: qcom: Add SM8750 GPU clocks

From: Krzysztof Kozlowski
Date: Thu Jul 24 2025 - 10:42:57 EST


On 24/07/2025 12:53, Konrad Dybcio wrote:
> On 7/24/25 10:18 AM, Krzysztof Kozlowski wrote:
>> On Wed, Jul 23, 2025 at 10:38:48PM +0200, Konrad Dybcio wrote:
>>> From: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>
>>>
>>> The SM8750 features a "traditional" GPU_CC block, much of which is
>>> controlled through the GMU microcontroller. Additionally, there's
>>> an separate GX_CC block, where the GX GDSC is moved.
>>>
>>> Add bindings to accommodate for that.
>>>
>>> Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>
>>> ---
>
> [...]
>
>>> +title: Qualcomm Graphics Clock & Reset Controller on SM8750
>>
>> There is no clocks nor resets here. Only power domains.
>
> There are clocks and resets in this IP block (inside the register
> space mentioned in the dt patch/example), but the OS is not supposed
> to poke at them (it can in theory, but we have a uC - the GMU -
> doing the same thing so it would be stepping on one another's toes..).
> Not sure how to express that.
>
> I could for example add #define indices in include/dt-bindings, listing
> out the clocks and never consume them. Does that sound fair?

Explain that in the binding description.

>
>>
>>> +
>>> +maintainers:
>>> + - Konrad Dybcio <konradybcio@xxxxxxxxxx>
>>> +
>>> +description: |
>>> + Qualcomm graphics clock control module provides the clocks, resets and power
>>
>> Also confusing.
>>
>>> + domains on Qualcomm SoCs.
>>> +
>>> + See also:
>>> + include/dt-bindings/reset/qcom,sm8750-gpucc.h
>>
>> reset or clock path?
>
> Ugh, clock
>
>>
>>> +
>>> +properties:
>>> + compatible:
>>> + enum:
>>> + - qcom,sm8750-gxcc
>>> +
>>> + reg:
>>> + maxItems: 1
>>> +
>>> + power-domains:
>>> + items:
>>> + - description: GFX voltage rail
>>> + - description: MX_COLLAPSIBLE voltage rail
>>> + - description: GPU_CC_CX GDSC
>>> +
>>> + '#power-domain-cells':
>>> + const: 1
>>> +
>>> +required:
>>> + - compatible
>>> + - power-domains
>>> + - '#power-domain-cells'
>>> +
>>
>> You miss ref... or this is a bit confusing.
> ref to what? qcom,gcc? I specifically omitted it, as that adds
> requirements which you stated above.

Yes, qcom,gcc. If that was missing intentionally, it is fine assuming
you implement the rest of comments.


Best regards,
Krzysztof