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

From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
To: Felipe Balbi <balbi@kernel.org>
Cc: Guenter Roeck <linux@roeck-us.net>,
	Greg KH <gregkh@linuxfoundation.org>,
	linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
	Mathias Nyman <mathias.nyman@linux.intel.com>
Subject: Re: [PATCH 0/3] usb: USB Type-C Class and driver for UCSI
Date: Fri, 6 May 2016 11:23:47 +0300	[thread overview]
Message-ID: <20160506082347.GC29820@kuha.fi.intel.com> (raw)
In-Reply-To: <87h9ebistj.fsf@intel.com>

On Fri, May 06, 2016 at 09:50:00AM +0300, Felipe Balbi wrote:
> 
> Hi Guenter,
> 
> Guenter Roeck <linux@roeck-us.net> writes:
> > 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.
> >
> > Is there any chance to advance this patch set ? It would be instrumental
> > to get a unified interface to user space.
> 
> A newer version of $subject is already in Greg's queue [1]
> 
> [1] https://git.kernel.org/cgit/linux/kernel/git/gregkh/usb.git/commit/?h=usb-next&id=0c1849a8c7af652c92ad0265a7ca5934fd773c69

No that only has the separated UCSI driver, not the class.

-- 
heikki