lkml.org 
[lkml]   [2016]   [Aug]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCHv6 1/3] usb: USB Type-C connector class
Hi Vincent,

On Fri, Aug 26, 2016 at 03:16:16PM +0200, Vincent Palatin wrote:
> >> > +What: /sys/class/typec/<port>/current_vconn_role
> >> > +Date: June 2016
> >> > +Contact: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> >> > +Description:
> >> > + Shows the current VCONN role of the port. This attribute can be
> >> > + used to request VCONN role swap on the port when the port
> >> > + supports USB Power Delivery.
> >> > +
> >> > + Valid values are:
> >> > + - source
> >> > + - sink
> >>
> >>
> >> either we are currently sourcing vconn or not, but even if you are
> >> not, you are probably not a vconn sink either (ie only vconn-powered
> >> accessory are, your usual linux-powered laptop/phone is probably not)
> >
> > It's not relevant to know whether the vconn is being actually used or
> > not here. I'm not sure what's your point?
>
>
> My point was: saying we are a VCONN "sink" just because we are not
> currently sourcing vconn is usually not true.

OK, I understand your point now. You are correct. I think we need to
change this attribute and call it "vconn_source" that reports "1" or
"0".

I'll change that and send one more version of these on Monday
(hopefully the last one) unless somebody disagrees.

> >> > +What: /sys/class/typec/<port>-partner/type
> >> > +Date: June 2016
> >> > +Contact: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> >> > +Description:
> >> > + Shows the type of the partner. Can be one of the following:
> >> > + - USB - When the partner is normal USB host/peripheral.
> >> > + - Charger - When the partner has been identified as dedicated
> >> > + charger.
> >> > + - Alternate Mode - When the partner supports Alternate Modes.
> >> > + - Accessory - When the partner is one of the accessories with
> >> > + specific Accessory Mode defined in USB Type-C
> >> > + specification.
> >>
> >>
> >> where a dock would be classified ?
> >
> > A dock is just USB PD capable device with a bunch of alternate modes
> > that is attached to the port. There is no specific identifier for a
> > "dock".
>
> My remark was a bit too stern,
> I meant a dock might be 'USB' 'Charger' 'Alternate Mode' , all at the
> same time or alternately depending what you plug in.
> I don't really see those types as mutually exclusive.

So USB type means the partner does not have alternate modes (I'll
clear that in the documentation), Charger is a dedicated charger and
therefore can not be anything else (no USB, no alternate modes).

To answer your original question, a dock would be reported as
Alternate Mode.


Thanks,

--
heikki

\
 
 \ /
  Last update: 2016-09-17 09:57    [W:0.069 / U:1.352 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site