Re: [PATCH V2] usb: typec: Add sysfs node to show connector orientation

[Heikki Krogerus <heikki.krogerus@linux.intel.com>]

On Wed, Oct 23, 2019 at 06:44:39AM -0700, Guenter Roeck wrote:
> On 10/23/19 1:32 AM, Heikki Krogerus wrote:
> > +Guenter
> > 
> > On Tue, Oct 22, 2019 at 04:59:24PM +0800, Puma Hsu wrote:
> > > Export the Type-C connector orientation so that user space
> > > can get this information.
> > > 
> > > Signed-off-by: Puma Hsu <pumahsu@google.com>
> > > ---
> > >   Documentation/ABI/testing/sysfs-class-typec | 11 +++++++++++
> > >   drivers/usb/typec/class.c                   | 18 ++++++++++++++++++
> > >   2 files changed, 29 insertions(+)
> > > 
> > > diff --git a/Documentation/ABI/testing/sysfs-class-typec b/Documentation/ABI/testing/sysfs-class-typec
> > > index d7647b258c3c..b22f71801671 100644
> > > --- a/Documentation/ABI/testing/sysfs-class-typec
> > > +++ b/Documentation/ABI/testing/sysfs-class-typec
> > > @@ -108,6 +108,17 @@ Contact:	Heikki Krogerus <heikki.krogerus@linux.intel.com>
> > >   Description:
> > >   		Revision number of the supported USB Type-C specification.
> > > +What:		/sys/class/typec/<port>/connector_orientation
> > > +Date:		October 2019
> > > +Contact:	Puma Hsu <pumahsu@google.com>
> > > +Description:
> > > +		Indicates which typec connector orientation is configured now.
> > > +		cc1 is defined as "normal" and cc2 is defined as "reversed".
> > > +
> > > +		Valid value:
> > > +		- unknown (nothing configured)
> > 
> > "unknown" means we do not know the orientation.
> > 
> > > +		- normal (configured in cc1 side)
> > > +		- reversed (configured in cc2 side)
> > 
> > Guenter, do you think "connector_orientation" OK. I proposed it, but
> > I'm now wondering if something like "polarity" would be better?
> > 
> 
> Yes, or just "orientation". I don't see the value in the "connector_" prefix.
> I also wonder if "unknown" is really correct. Is it really unknown, or
> does it mean that the port is disconnected ?

Unknown means we don't know the orientation. We don't always have that
information available to us. With UCSI we simply do not know it.

I think this file needs to be hidden after all if we don't know the
cable plug orientation.

How about empty string instead of "unknown"?

thanks,

-- 
heikki