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Message-ID: <a8012b92-6072-406d-8aab-ecb167ea44d2@quicinc.com>
Date: Thu, 4 Jan 2024 18:40:53 +0800
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Subject: Re: [PATCH] arm64: dts: qcom: ipq6018: add #power-domain-cells for
 gcc node
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To: Robert Marko <robimarko@gmail.com>,
        Konrad Dybcio
	<konrad.dybcio@linaro.org>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        <quic_tdas@quicinc.com>, <quic_aiquny@quicinc.com>
CC: <kernel@quicinc.com>, Andy Gross <agross@kernel.org>,
        Bjorn Andersson
	<andersson@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski
	<krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>, <linux-arm-msm@vger.kernel.org>,
        <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>
References: <20240104-gcc-docs-update-v1-1-127e4816b798@quicinc.com>
 <CAA8EJprsGke9zZBy_x=YSxz7R1aSpx8r3ndjjXVVKhjKBxd=QQ@mail.gmail.com>
 <724f608a-cbfe-48f6-a1f7-59b961a7d724@quicinc.com>
 <56ee556d-ec31-4553-bce3-0c1e12c111ed@linaro.org>
 <685f45d9-48e8-49c6-9de0-6771777ba62e@gmail.com>
From: Fenglin Wu <quic_fenglinw@quicinc.com>
In-Reply-To: <685f45d9-48e8-49c6-9de0-6771777ba62e@gmail.com>
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On 1/4/2024 6:32 PM, Robert Marko wrote:
> 
> On 04. 01. 2024. 11:16, Konrad Dybcio wrote:
>> On 4.01.2024 11:13, Fenglin Wu wrote:
>>>
>>> On 1/4/2024 5:53 PM, Dmitry Baryshkov wrote:
>>>> On Thu, 4 Jan 2024 at 10:06, Fenglin Wu via B4 Relay
>>>> <devnull+quic_fenglinw.quicinc.com@kernel.org> wrote:
>>>>> From: Fenglin Wu <quic_fenglinw@quicinc.com>
>>>>>
>>>>> Property '#power-domain-cells' is required as per defined in 
>>>>> qcom,gcc.yaml
>>>>> so add it for ipq6018 gcc device node to eliminate following 
>>>>> warning in
>>>>> dtbs_check:
>>>>>
>>>>> arch/arm64/boot/dts/qcom/ipq6018-cp01-c1.dtb: gcc@1800000:
>>>>>           '#power-domain-cells' is a required property
>>>>> from schema $id: 
>>>>> http://devicetree.org/schemas/clock/qcom,gcc-ipq6018.yaml#
>>>> But ipq6018 doesn't implement GDSC support. So for the sake of fixing
>>>> the warning you are adding a bogus property.
>>>>
>>> I agree. However, there are also some gcc drivers not implementing 
>>> GDSC support but the bindings are adding '#power-domain-cells' in the 
>>> DT example, such as: qcom,gcc-apq8064.yaml, qcom,gcc-ipq4019.yaml, 
>>> qcom,gcc-ipq6018.yaml, qcom,gcc-ipq8064.yaml, qcom,gcc-msm8660.yaml.
>>>
>>> Actually I thought that maybe we should do a clean up by removing 
>>> '#power-domain-cells' out of the qcom,gcc.yaml binding and only 
>>> adding it into individual qcom,gcc-xxx.yaml for the driver which has 
>>> implemented GDSC support. I checked this with Taniya offline, but she 
>>> prefers only fixing it in ipq6018.dtsi as it doesn't hurt anything by 
>>> adding the property, and she expects the GDSC support should be 
>>> existing in most of qcom,gcc drivers especially the newer Qcom chipsets.
>> Before we start changing anything, we should assess whether these
>> platforms actually have GDSCs within this clock controller block,
>> even if they are (currently) not described in the clk driver.
> Hi,
> IPQ6018 has GDSC-s, at least for the USB-s.
> I tried configuring them a while ago, but the USB2.0 GDSC seems to 
> either have a HW bug or
> it uses some special configuration as its status bits never show that 
> its ON [1].
> 
> [1] 
> https://patchwork.kernel.org/project/linux-arm-msm/patch/20231025104457.628109-2-robimarko@gmail.com/
> 
Thanks for the link! I checked the spec internal, and I did see GDSC 
device for USB0/USB1 controller is present in GCC clock controller.
So considering there is a patch ongoing to add GDSC device for ipq6018 
gcc driver, can the DT commit which adds '#power-domain-cells' be accepted?

> Regards,
> Robert
> 
>>
>> Konrad