Rk3399 - Typec - Extcon

[Dragan Simic]

On 2023-12-08 05:18, Da Xue wrote:
> On Thu, Dec 7, 2023 at 7:07 PM Dragan Simic <dsimic at manjaro.org> wrote:
>> Hello Shantur,
>> 
>> On 2023-12-07 22:12, Shantur Rathore wrote:
>> > Hi Jagan,
>> >
>> > While trying to figure out issues with Typec AltMode + SuperSpeed on
>> > mainline for Rk3399 based RockPro64, I came across your proposed patch
>> > for TypeC Virtual PD Driver [0].
> 
> I went to the FUSB302/TCPM stack issues for ROC-RK3399-PC, see the
> patches needed here
> https://github.com/libre-computer-project/libretech-builder-simple/issues/2#issuecomment-1837269475
> 
> A major issue is the lack of a driver in u-boot which causes many
> non-conformant power supplies to time out causing error messages. The
> patches above do their best to keep the stack working despite this.

Huh, you made a good point, thanks!  That's something to think a lot 
about;  actually, a similar PD issue was discussed in the Pine64 
community chats a few times, while discussing some Pinebook Pro's 
power-related issues.

>> > Would you know if there's been any other development on supporting
>> > Rockchip-TypeC-Phy with FUSB302 boards like RockPro64 or PineBook Pro.
>> >
>> > [0] -
>> > https://lore.kernel.org/lkml/20200904191830.387296-3-jagan@amarulasolutions.com/T/#m7b5d674764379253568a4915f2f9988d74c86593
>> 
>> Basically, we need to get rid of the whole extcon hack, as described 
>> in
>> the thread linked above, which is a massive job that borders with a
>> complete rewrite.  I'll probably (and hopefully :) dive into all that 
>> in
>> the foreseeable future.
> 
> extcon is a dead end. Dmitri is using something else for Qualcomm but
> I'm not sure how much overlap there is with the standard TCPM.

AFAIK, some Qualcomm-based smartphones, e.g. OnePlus 6T, use some 
non-standard charger negotiation mechanism.  I could easily be wrong 
there, though.