On Thu, Sep 20, 2018 at 10:21:59AM +0200, Heiko Stuebner wrote: > Hi Guenter, > > Am Montag, 13. August 2018, 14:29:15 CEST schrieb Guenter Roeck: > > On 08/13/2018 03:36 AM, Heiko Stuebner wrote: > > > Hi, > > > > > > I'm currently trying to wrap my head around the new typec subsystem and > > > also how to do it correctly on Rockchip rk3399 devices. > > > > > > The issue (and Guenter might know quite a bit about that) is that on > > > ChromeOS devices the embedded controller hides the whole tcpm/vdm > > > logic from the operating system and just provides a custom interface to > > > query things like cable state, display-port hotplug status and so on. > > > > > > So right now the rk3399-typec-phy uses that extcon-based interface to > > > get all status changes but that of course leaves out all systems directly > > > talking to a fusb302. I did a small drawing to showcase that: > > > > > > ------------- ------------------ > > > | typec-phy |----| extcon-cros-ec |\ > > > ------------- ------------------ \ > > > | \ \ > > > ------------- \ ------------------ \ ----------- > > > | cdn-dp | \| ????? |-----| fusb302 | > > > ------------- ------------------ ----------- > > > > > > So to bring everything on the same page, I guess the cros-ec extcon > > > (drivers/extcon/extcon-usbc-cros-ec.c) should somehow use the typec > > > functions instead of implementing an extcon? But from reading into the > > > typec code, it somehow looks like the typec framework expects to be in > > > control of things like altmode negotiations, or am I misreading something? > > > > > I used to have a patch for the cros-ec extcon driver which ties it into the > > typec subsystem. Let me see if I can dig it up. > > were your archeological skills working in finding said old patch? > Not very well :-( Guenter
