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Message-ID: <c70c1a4d-50c5-2b50-18c9-7c46c3803cd4@linaro.org>
Date:   Tue, 11 Apr 2023 13:27:17 +0200
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Subject: Re: [PATCH 2/3] dt-bindings: clock: qcom,gcc-sc7180: document CX
 power domain
Content-Language: en-US
To:     Rajendra Nayak <quic_rjendra@quicinc.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Taniya Das <tdas@codeaurora.org>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        linux-arm-msm@vger.kernel.org, linux-clk@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20230408134820.76050-1-krzysztof.kozlowski@linaro.org>
 <20230408134820.76050-2-krzysztof.kozlowski@linaro.org>
 <4757c33c-7e71-262d-a51a-c5f9fb53ff41@linaro.org>
 <d4a8054c-443e-d9ba-9641-ff721254d254@quicinc.com>
From:   Konrad Dybcio <konrad.dybcio@linaro.org>
In-Reply-To: <d4a8054c-443e-d9ba-9641-ff721254d254@quicinc.com>
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On 11.04.2023 06:56, Rajendra Nayak wrote:
> 
> 
> On 4/8/2023 7:33 PM, Konrad Dybcio wrote:
>>
>>
>> On 8.04.2023 15:48, Krzysztof Kozlowski wrote:
>>> The GCC clock controller needs CX power domain, at least according to
>>> DTS:
>>>
>>>    sc7180-trogdor-pompom-r3.dtb: clock-controller@100000: Unevaluated properties are not allowed ('power-domains' was unexpected)
>>>
>>> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
>>> ---
>> +CC Rajendra (author of 5d6fc6321db1 ("arm64: dts: qcom:
>> sc7180: Add required-opps for USB"))
>>
>> Rajendra, shouldn't SC7180 GCC have PM ops to make sure a vote
>> is only there when AP is active?
So IIUC, CX is never supposed to be shut down?

Konrad
> 
> hmm, I am not quite sure why we would want the performance votes
> from peripherals dropped when CPUs go down in idle?
> 
>> Are all GDSCs powered by CX?
>> If not, wouldn't this also need power-domain-names to
>> facilitate e.g. potential MX-powered ones?
> 
> For sc7180 GCC, yes.
> 
>>
>> Konrad
>>>   .../devicetree/bindings/clock/qcom,gcc-sc7180.yaml         | 7 +++++++
>>>   1 file changed, 7 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/clock/qcom,gcc-sc7180.yaml b/Documentation/devicetree/bindings/clock/qcom,gcc-sc7180.yaml
>>> index 06dce0c6b7d0..8bf9b6f49550 100644
>>> --- a/Documentation/devicetree/bindings/clock/qcom,gcc-sc7180.yaml
>>> +++ b/Documentation/devicetree/bindings/clock/qcom,gcc-sc7180.yaml
>>> @@ -32,6 +32,10 @@ properties:
>>>         - const: bi_tcxo_ao
>>>         - const: sleep_clk
>>>   +  power-domains:
>>> +    items:
>>> +      - description: CX domain
>>> +
>>>   required:
>>>     - compatible
>>>     - clocks
>>> @@ -45,6 +49,8 @@ unevaluatedProperties: false
>>>   examples:
>>>     - |
>>>       #include <dt-bindings/clock/qcom,rpmh.h>
>>> +    #include <dt-bindings/power/qcom-rpmpd.h>
>>> +
>>>       clock-controller@100000 {
>>>         compatible = "qcom,gcc-sc7180";
>>>         reg = <0x00100000 0x1f0000>;
>>> @@ -52,6 +58,7 @@ examples:
>>>                  <&rpmhcc RPMH_CXO_CLK_A>,
>>>                  <&sleep_clk>;
>>>         clock-names = "bi_tcxo", "bi_tcxo_ao", "sleep_clk";
>>> +      power-domains = <&rpmhpd SC7180_CX>;
>>>         #clock-cells = <1>;
>>>         #reset-cells = <1>;
>>>         #power-domain-cells = <1>;