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

[Chaoyi Chen <chaoyi.chen@rock-chips.com>]

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@airkyi.com/
>>
>> 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


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