On Fri, Oct 18, 2019 at 12:59 PM Hans de Goede <hdegoede@xxxxxxxxxx> wrote: > On 18-10-2019 21:53, John Stultz wrote: > > On Fri, Oct 18, 2019 at 12:30 PM Hans de Goede <hdegoede@xxxxxxxxxx> wrote: > >> Looking at drivers/usb/typec/tcpm/tcpci.c: tcpci_set_vconn I see that > >> there is a data struct with vendor specific callbacks and that the > >> drivers/usb/typec/tcpm/tcpci_rt1711h.c implements that. > >> > >> So you may want something similar here. But things are tricky here, > >> because when nothing is connected you want to provide Vbus for > >> the USB-A ports, which means that if someone then connects a > >> USB-A to C cable to connect the board to a PC (switching the port > >> to device mode) there will be a time when both sides are supplying > >> 5V if I remember the schedule correctly. > > > > Ok. Thanks for the pointer, I'll take a look at that to see if I can > > get it to work. > > > >> I think that the original hack might not be that bad, the whole hw > >> design seems so, erm, broken, that you probably cannot do proper > >> roleswapping anyways. So just tying Vbus to host mode might be > >> fine, the question then becomes again how can some other piece > >> of code listen to the role-switch events... > > > > So, at least in the current approach (see the v3 series), I've > > basically set the hub driver as an role-switch intermediary, sitting > > between the calls from the tcpm to the dwc3 driver. It actually works > > better then the earlier notifier method (which had some issues with > > reliably establishing the initial state on boot). Does that approach > > work for you? > > That sounds like it might be a nice solution. But I have not seen the > code, I think I was not Cc-ed on v3. Do you have a patchwork or > lore.kernel.org link for me? Oh! I think I had you on CC, maybe it got caught in your spam folder? My apologies either way! The thread is here: https://lore.kernel.org/lkml/20191016033340.1288-1-john.stultz@xxxxxxxxxx/ And the hub/role-switch-intermediary driver is here: https://lore.kernel.org/lkml/20191016033340.1288-12-john.stultz@xxxxxxxxxx/ thanks -john
