Re: [PATCH 0/3] usb: USB Type-C Class and driver for UCSI

[Guenter Roeck]

On 05/06/2016 01:08 AM, Heikki Krogerus wrote:
> Hi,
>
> On Wed, May 04, 2016 at 08:05:44PM -0700, Guenter Roeck wrote:
> > On Tue, Feb 09, 2016 at 07:01:20PM +0200, Heikki Krogerus wrote:
> > > Hi,
> > >
> > > The OS, or more precisely the user space, needs to be able to control
> > > a few things regarding USB Type-C ports. The first thing that must be
> > > allowed to be controlled is the data role. USB Type-C ports will
> > > select the data role randomly with DRP ports. When USB PD is
> > > supported, also independent (from data role) power role swapping can
> > > be supported together with Alternate Mode control.
> > >
> > > I'm proposing with this set a Class for the Type-C connectors that
> > > gives the user space control over those things on top of getting basic
> > > details about the USB Type-C connectors and also partners. The details
> > > include the capabilities of the port, the supported data and power
> > > roles, supported accessories (audio and debug), supported Alternate
> > > Modes, USB PD support and of course the type of the partner (USB, Alt
> > > Mode, Accessory or Charger), and more or less the same details about
> > > the partner.
> > >
> > > I'm not considering cables with this Class, and I have deliberately
> > > left out some more technical details, like cable orientation, firstly
> > > because I did not see much use for the user space from knowing that
> > > an secondly because that kind of details are not always available for
> > > example with UCSI.
> > >
> > > So the interface to the user space is kept as simple as I dared to
> > > make it.
> > >
> > > NOTE: In case there is somebody wondering, this is not adding USB PD
> > > support to Linux kernel. This is just about USB Type-C.
> >
> > Hello Heikki,
> >
> > we have implemented a prototype TCPM (USB Type-C Protocol Manager)
> > software on top of your patch set. It will support TCPCI as well
> > as other USB-C controllers such as FUSB302. The plan is to use
> > this software in systems where no separate controller is available.
>
> Interesting. So I'm guessing TCPM is actually an implementation USB PD
> software stack, no? AFAIK FUSB302 has USB PD transceiver, right?
Yes, both correct.

> > Is there any chance to advance this patch set ? It would be instrumental
> > to get a unified interface to user space.
>
> I don't have not made any new code for the class driver yet, but I'm
> attempting to prepare v2 next week.

Excellent! Please cc me - either this e-mail address or groeck@xxxxxxxxxxxxx

Thanks,
Guenter