Received-SPF: pass (google.com: domain of linux-kernel+bounces-57395-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
Message-ID: <fd4f4cc8-3366-485b-b540-b05ef59dd5d4@quicinc.com>
Date: Thu, 8 Feb 2024 08:10:10 +0530
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH 2/3] arm64: dts: qcom: sa8295p: Enable tertiary controller
 and its 4 USB ports
To: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        Krzysztof Kozlowski
	<krzysztof.kozlowski+dt@linaro.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>
CC: Rob Herring <robh+dt@kernel.org>, Bjorn Andersson <andersson@kernel.org>,
        Conor Dooley <conor+dt@kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-arm-msm@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <quic_ppratap@quicinc.com>, <quic_jackp@quicinc.com>
References: <20240206114745.1388491-1-quic_kriskura@quicinc.com>
 <20240206114745.1388491-3-quic_kriskura@quicinc.com>
 <CAA8EJpoed-hu4hPXAcwQxmJAaNRwJ2y5q9qybWaPP8bdMnz_oA@mail.gmail.com>
 <0470a930-d629-4467-b619-58d3e76f59a7@quicinc.com>
 <CAA8EJppJAdHXoVs_2VqQf=_Wk_LoEcNMY2H-Xzqu8KzeaN8i0g@mail.gmail.com>
Content-Language: en-US
From: Krishna Kurapati PSSNV <quic_kriskura@quicinc.com>
In-Reply-To: <CAA8EJppJAdHXoVs_2VqQf=_Wk_LoEcNMY2H-Xzqu8KzeaN8i0g@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 7bit


On 2/6/2024 6:54 PM, Dmitry Baryshkov wrote:
> On Tue, 6 Feb 2024 at 14:28, Krishna Kurapati PSSNV
> <quic_kriskura@quicinc.com> wrote:
>>
>>
>>
>> On 2/6/2024 5:43 PM, Dmitry Baryshkov wrote:
>>> On Tue, 6 Feb 2024 at 14:03, Krishna Kurapati <quic_kriskura@quicinc.com> wrote:
>>>>
>>>> Enable tertiary controller for SA8295P (based on SC8280XP).
>>>> Add pinctrl support for usb ports to provide VBUS to connected peripherals.
>>>
>>> These are not just pinctrl entries. They hide VBUS regulators. Please
>>> implement them properly as corresponding vbus regulators.
>>>
>>
>> Hi Dmitry. Apologies, can you elaborate on your comment. I thought this
>> implementation was fine as Konrad reviewed it in v13 [1]. I removed his
>> RB tag as I made one change of dropping "_state" in labels.
> 
> My comment is pretty simple: if I'm not mistaken, your DT doesn't
> reflect your hardware design.
> You have actual VBUS regulators driven by these GPIO pins. Is this correct?
> If so, you should describe them properly in the device tree rather
> than describing them just as USB host's pinctrl state.
> 

Hi Dmitry,

  I have very little idea about the gpio controller regulators. I will 
go through it and see how I can implement it. I just found this : 
https://www.kernel.org/doc/Documentation/devicetree/bindings/regulator/gpio-regulator.txt

One query. If we model it as a regulator, do we need to add it as a 
supply and call regulator_enable in dwc3_qcom probe again ?

Regards,
Krishna,