Re: [PATCH 1/2] dt-bindings: usb: Introduce GPIO-based SBU mux

Prashant Malani
2022-08-23T19:31:45Z

On Fri, Aug 19, 2022 at 9:04 PM Bjorn Andersson
<bjorn.andersson@linaro.org> wrote:
>
> On Fri 19 Aug 17:18 CDT 2022, Prashant Malani wrote:
>
> > On Fri, Aug 19, 2022 at 2:39 PM Bjorn Andersson
> > <bjorn.andersson@linaro.org> wrote:
>
> Are you saying that two of your SS-lanes in connector A are connected to
> directly to the QMP PHY at the same time as two SS-lanes from connector
> B are connected to the same two pads on the QMP PHY - without any
> mux etc inbetween?
>
> I.e. that there are a set of pins in connector A which is directly
> connected to a set of pins in connector B?
>
>
> I was under the impression that in your hardware there's some component
> muxing the single DP output to one of the connectors. If so there should
> be no graph-link directly connecting the two usb-c-connectors and the
> one QMP PHY.
>
> Is this not the case?

I can't speak to the QMP PHY specifically (since I'm not using that hardware),
but your impression is right.
There is a component (anx7625) muxing the single DP output to the 2
usb-c-connectors
(specifically, 2 lanes each from the 2 usb-c-connectors).
The other 2 lanes (from the 2 USB-C-connectors) go to a USB3 hub; hence the need
for 2 endpoints for each usb-c-connector).

So, the anx7625 should register the mode switches and it needs the
graph connections
from 2 usb-c-connectors

BR,

-Prashant