Re: [PATCH v8 10/10] arm64: dts: rockchip: rk3399-evb-ind: Add support for DisplayPort

[Chaoyi Chen]

On 10/30/2025 10:50 AM, Peter Chen wrote:

> > > Okay.  My question is basic: USB2 PHY supplies DP/DM, and the DP/DM is
> > > short for Type-C connector,
> > > and no control is needed for Type-C application.
> > > Why is there a remote-endpoint connection between USB2 PHY and Type-C connector?
> >   From the perspective of Type-C, this should not be added.  Is the approach in v2 correct [0] ?
> Have you tried debugging based on upstream code?

Yes, I have tried both the v2 and v8 approaches, and both can work.


> v2 is correct, but the dts needs to improve.
> - There is a remote-endpoint connection for USB role switch between
> Type-C connector
> device and USB controller device
> - There is a remote-endpoint connection for orientation and lane configuration
> between Type-C connector device and USB/DP PHY device.

In v8 patch5, we implemented typec_mux and typec_switch in the USB/DP PHY.

I think the current remote-endpoint connections are all child node of the USB/DP PHY. That is:


&tcphy0_dp {
    mode-switch;
    ...
};


&tcphy0_usb3 {
    orientation-switch;
    ...
};


Does this still need to be improved? Thank you.


> Peter
>
> > [0]: https://lore.kernel.org/all/20250715112456.101-6-kernel@xxxxxxxxxx/
> >
> > Or is the following approach correct?
> >
> >
> > port@0 {
> >       reg = <0>;
> >
> >       usbc_hs: endpoint {
> >           remote-endpoint = <&tcphy0>;
> >       };
> > };
> >
> > port@1 {
> >       reg = <1>;
> >
> >       usbc_ss: endpoint {
> >           remote-endpoint = <&tcphy0>;
> >       };
> > };
> >
> > port@2 {
> >       reg = <2>;
> >
> >       usbc_dp: endpoint {
> >           remote-endpoint = <&tcphy0_typec_dp>;
> >       };
> > };
> >
> >
> > > > > > > +                               port@1 {
> > > > > > > +                                       reg = <1>;
> > > > > > > +
> > > > > > > +                                       usbc_ss: endpoint {
> > > > > > > + remote-endpoint = <&tcphy0_typec_ss>;
> > > > > > > +                                       };
> > > > > > > +                               };
> > > > > > > +
> > > > > > > +                               port@2 {
> > > > > > > +                                       reg = <2>;
> > > > > > > +
> > > > > > > +                                       usbc_dp: endpoint {
> > > > > > > + remote-endpoint = <&tcphy0_typec_dp>;
> > > > > > > +                                       };
> > > > > > > +                               };
> > > > > > > +                       };
> > > > > > > +               };
> > > > > > > +       };
> > > > > > > +};
> > > > > > > +
> > > > > > .....
> > > > > > >     &u2phy0 {
> > > > > > >            status = "okay";
> > > > > > > +
> > > > > > > +       port {
> > > > > > > +               u2phy0_typec_hs: endpoint {
> > > > > > > +                       remote-endpoint = <&usbc_hs>;
> > > > > > > +               };
> > > > > > > +       };
> > > > > > >     };
> > > > > > There is no switch and mux, how to co-work with Type-C?
> > > > > I checked the phy-rockchip-inno-usb2.c but did not find any switch or mux. Does this mean that we need to implement them? Thank you.
> > > > Wait a minute, actually we have multiple hardware interfaces, one of which is Type-C, eventually connected to USBDPPHY, and the other is micro-usb connected to U2PHY.
> > > I assume the Micro-USB connector does not use Type-C/PD IC, is it
> > > right? Does it relate to this patch?
> > >
> > > Best regards,
> > > Peter
--
Best,
Chaoyi