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Date:   Thu, 27 Apr 2023 12:52:32 -0700
From:   Bjorn Andersson <quic_bjorande@quicinc.com>
To:     Bryan O'Donoghue <pure.logic@nexus-software.ie>
CC:     Vinod Koul <vkoul@kernel.org>,
        Kishon Vijay Abraham I <kishon@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Johan Hovold <johan@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        <linux-arm-msm@vger.kernel.org>, <linux-phy@lists.infradead.org>,
        <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/7] dt-bindings: phy: qcom,sc8280xp-qmp-usb43dp: Add
 ports and orientation-switch
Message-ID: <20230427195232.GB870858@hu-bjorande-lv.qualcomm.com>
References: <20230425034010.3789376-1-quic_bjorande@quicinc.com>
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 <CAJB8c06H+3pxoUGXWOXyCgtbOj6y0OhSxb9dvoTo1b6iChy7ng@mail.gmail.com>
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On Wed, Apr 26, 2023 at 11:21:29AM +0100, Bryan O'Donoghue wrote:
> On Tue, Apr 25, 2023 at 4:40 AM Bjorn Andersson
> <quic_bjorande@quicinc.com> wrote:
> >
> > The QMP combo phy can be connected to a TCPM, a USB controller and a
> > DisplayPort controller for handling USB Type-C orientation switching
> > and propagating HPD signals.
> >
> > Extend the binding to allow these connections to be described.
> >
> > Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
> > ---
> >  .../phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml    | 51 +++++++++++++++++++
> >  1 file changed, 51 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml b/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml
> > index 3cd5fc3e8fab..c037ac90ce7f 100644
> > --- a/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml
> > +++ b/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml
> > @@ -60,6 +60,26 @@ properties:
> >      description:
> >        See include/dt-bindings/dt-bindings/phy/phy-qcom-qmp.h
> >
> > +  orientation-switch:
> > +    description:
> > +      Flag the PHY as possible handler of USB Type-C orientation switching
> > +    type: boolean
> > +
> > +  ports:
> > +    $ref: /schemas/graph.yaml#/properties/ports
> > +    properties:
> > +      port@0:
> > +        $ref: /schemas/graph.yaml#/properties/port
> > +        description: Output endpoint of the PHY
> > +
> > +      port@1:
> > +        $ref: /schemas/graph.yaml#/$defs/port-base
> > +        description: Incoming endpoint from the USB controller
> 
> Do you really need this one ?
> 
> The controller doesn't process orientation switching.
> 

I don't have a need for it, as we can deal with role switching by
connecting connector/port@0 to the dwc3.

But if we ever have a need to describe the dwc3 -> QMP -> connector path
in the of_graph I think it would look prettier to have USB input as
port@1 and DP input as port@2...

Do you have a concern with keeping it around in the DT (the
implementation doesn't need to care)?

Regards,
Bjorn