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

[Peter Chen <hzpeterchen@gmail.com>]

On Wed, Oct 29, 2025 at 6:32 PM Chaoyi Chen <chaoyi.chen@rock-chips.com> wrote:
>
> On 10/29/2025 6:21 PM, Chaoyi Chen wrote:
>
> > Hi Peter,
> >
> > On 10/29/2025 5:45 PM, Peter Chen wrote:
> >>> +&i2c4 {
> >>> +       i2c-scl-rising-time-ns = <475>;
> >>> +       i2c-scl-falling-time-ns = <26>;
> >>> +       status = "okay";
> >>> +
> >>> +       usbc0: typec-portc@22 {
> >>> +               compatible = "fcs,fusb302";
> >>> +               reg = <0x22>;
> >>> +               interrupt-parent = <&gpio1>;
> >>> +               interrupts = <RK_PA2 IRQ_TYPE_LEVEL_LOW>;
> >>> +               pinctrl-names = "default";
> >>> +               pinctrl-0 = <&usbc0_int>;
> >>> +               vbus-supply = <&vbus_typec>;
> >>> +
> >>> +               usb_con: connector {
> >>> +                       compatible = "usb-c-connector";
> >>> +                       label = "USB-C";
> >>> +                       data-role = "dual";
> >>> +                       power-role = "dual";
> >>> +                       try-power-role = "sink";
> >>> +                       op-sink-microwatt = <1000000>;
> >>> +                       sink-pdos =
> >>> +                               <PDO_FIXED(5000, 2500, PDO_FIXED_USB_COMM)>;
> >>> +                       source-pdos =
> >>> +                               <PDO_FIXED(5000, 1500, PDO_FIXED_USB_COMM)>;
> >>> +
> >>> +                       altmodes {
> >>> +                               displayport {
> >>> +                                       svid = /bits/ 16 <0xff01>;
> >>> +                                       vdo = <0x00001c46>;
> >>> +                               };
> >>> +                       };
> >>> +
> >>> +                       ports {
> >>> +                               #address-cells = <1>;
> >>> +                               #size-cells = <0>;
> >>> +
> >>> +                               port@0 {
> >>> +                                       reg = <0>;
> >>> +
> >>> +                                       usbc_hs: endpoint {
> >>> + remote-endpoint = <&u2phy0_typec_hs>;
> >>> +                                       };
> >>> +                               };
> >>> +
> >> Why USB2 PHY needs to be notified for Type-C connection?
> >
> > I think the USB-connector binding require a port@0 for High Speed.  So I filled in USB2 PHY here. And I have looked up boards with the same usage, and some of the results are as follows:
> >
> > - rk3399-firefly.dts
> >
> > - rk3399-pinebook-pro.dts
> >
> > - rk3399-eaidk-610.dts
> >

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?

> >
> >>
> >>> +                               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