Re: [PATCH v2] arm64: dts: qcom: hamoa-iot-evk: switch typec0 to PS8830 retimer

Xin Liu <[email protected]> Tue, 4 Aug 2026 15:04:58 +0800
Newsgroups org.kernel.vger.linux-arm-msm,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
On 8/4/2026 3:35 AM, Dmitry Baryshkov wrote:
> On Mon, Aug 03, 2026 at 06:27:47AM -0700, Xin Liu wrote:
>> The Hamoa IoT EVK hardware design uses a Parade PS8830 retimer on
>> I2C3 for USB Type-C port 0. Describe the retimer and route typec0
>> through it to enable USB 3.0 SuperSpeed and DisplayPort Alt Mode.
>>
>> Supply the PS8830 from the existing vreg_rtmr0_* rails and remove
>> their stale "Left unused" annotation.
>>
>> The FSUSB42 SBU mux chip is present on the PCB but with all signal
>> lines unconnected (NC), so remove the fsusb42 node and its pinctrl
>> group.
> Why is it still present on the PCB?

The FSUSB42 is retained on the PCB as a fallback for the PS8830's SBU 
mux function.

Should the PS8830's SBU path encounter any issues, the FSUSB42 can 
be activated

with a simple rework to quickly switch to a discrete solution, avoiding 
a full board respin.


Thanks,
Xin

>> Tested on the Hamoa IoT EVK:
>>
>> USB 3.0 SuperSpeed at 5 Gbps on typec0
>> DisplayPort Alt Mode on typec0
>>
>> Signed-off-by: Guodong Xu <[email protected]>
>> Signed-off-by: Xin Liu <[email protected]>
> Reviewed-by: Dmitry Baryshkov <[email protected]>
>
>