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

[Heikki Krogerus]

Hi Rajaram,

On Thu, Feb 18, 2016 at 01:04:48AM +0530, Rajaram R wrote:
> On Tue, Feb 9, 2016 at 10:31 PM, Heikki Krogerus
> <heikki.krogerus@xxxxxxxxxxxxxxx> 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
> 
> Since we have capability details of ports in user space, I believe
> cable capability is also necessary for policy decision(power, alt
> mode). Is that something we are cautiously leaving out ? pls explain

Adding the cable control to this interface will make it more complex
from users perspective. However, nothing forces the user to control
also the cable.

I already decided to add vconn_swap support, so I'll try to add cable
alt mode control and capabilities as well.


Thanks,

-- 
heikki