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Message-ID: <f0820464-16d6-47fd-90bc-cf80b5d76058@quicinc.com>
Date:   Fri, 3 Nov 2023 11:04:59 +0530
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Subject: Re: [RFC 1/8] dt-bindings: usb: qcom,dwc3: Add bindings to enable
 runtime
To:     Caleb Connolly <caleb.connolly@linaro.org>,
        Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
        Bjorn Andersson <andersson@kernel.org>,
        "Konrad Dybcio" <konrad.dybcio@linaro.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
CC:     <quic_wcheng@quicinc.com>, <linux-usb@vger.kernel.org>,
        Conor Dooley <conor+dt@kernel.org>,
        <linux-kernel@vger.kernel.org>, <linux-arm-msm@vger.kernel.org>,
        Andy Gross <agross@kernel.org>,
        "Philipp Zabel" <p.zabel@pengutronix.de>,
        Rob Herring <robh+dt@kernel.org>,
        "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
        <devicetree@vger.kernel.org>, <quic_ppratap@quicinc.com>,
        <quic_jackp@quicinc.com>
References: <20231017131851.8299-1-quic_kriskura@quicinc.com>
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 <dbf4a48e-c808-4611-96b1-563ece1e451a@linaro.org>
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From:   Krishna Kurapati PSSNV <quic_kriskura@quicinc.com>
In-Reply-To: <dbf4a48e-c808-4611-96b1-563ece1e451a@linaro.org>
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On 11/3/2023 12:10 AM, Caleb Connolly wrote:
>> Hi Caleb,
>>
>>    There are two types of platforms, some use extcon and some use 
>> role-switch to deliver vbus/id notifications. Extcon targets already 
>> have this qscratch modifications present today in vbus and id 
>> handlers. But for role-switch based targets we don't have any way to 
>> get this notification to dwc3-qcom. In this implementation, I wanted 
>> to get those notications from core to glue and for this we implenented 
>> vendor hooks.
>>
>> The property added has been used to do two things:
>>
>> 1. Register glue's vendor hooks to core driver
>> 2. Do runtime_allow for glue (and by default for core as the dt is not 
>> flattened)
>>
>> In case of extcon, we don't want to register vendor hooks as 
>> notifications are not necessary.
> 
> Could it just be enabled when role_switch is present then?
>>

So we would register vendor hooks when usb-role-switch is present but 
don't do runtime allow, and leave that option to user space right ?
I think it would work and we can do away with the binding completely.

Will wait for comments from other folks as well on this approach.

Thanks for the review,
Krishna,