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

From: Rajaram R <rajaram.officemail@gmail.com>
To: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Greg KH <gregkh@linuxfoundation.org>,
	"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
	linux-kernel@vger.kernel.org,
	Mathias Nyman <mathias.nyman@linux.intel.com>,
	Felipe Balbi <balbi@kernel.org>
Subject: Re: [PATCH 0/3] usb: USB Type-C Class and driver for UCSI
Date: Thu, 18 Feb 2016 01:04:48 +0530	[thread overview]
Message-ID: <CAOiXha+Cj4vioeoHt=t0rO1CsLHecn++rBfdXXJBb+Wsi53L+Q@mail.gmail.com> (raw)
In-Reply-To: <1455037283-106479-1-git-send-email-heikki.krogerus@linux.intel.com>

On Tue, Feb 9, 2016 at 10:31 PM, Heikki Krogerus
<heikki.krogerus@linux.intel.com> 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

> 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.
>
>
> Heikki Krogerus (3):
>   usb: USB Type-C Connector Class
>   usb: type-c: USB Type-C Connector System Software Interface
>   usb: type-c: UCSI ACPI driver
>
>  drivers/usb/Kconfig            |   2 +
>  drivers/usb/Makefile           |   2 +
>  drivers/usb/type-c/Kconfig     |  25 +++
>  drivers/usb/type-c/Makefile    |   3 +
>  drivers/usb/type-c/typec.c     | 446 ++++++++++++++++++++++++++++++++++++++++
>  drivers/usb/type-c/ucsi.c      | 450 +++++++++++++++++++++++++++++++++++++++++
>  drivers/usb/type-c/ucsi.h      | 219 ++++++++++++++++++++
>  drivers/usb/type-c/ucsi_acpi.c | 133 ++++++++++++
>  include/linux/usb/typec.h      | 114 +++++++++++
>  9 files changed, 1394 insertions(+)
>  create mode 100644 drivers/usb/type-c/Kconfig
>  create mode 100644 drivers/usb/type-c/Makefile
>  create mode 100644 drivers/usb/type-c/typec.c
>  create mode 100644 drivers/usb/type-c/ucsi.c
>  create mode 100644 drivers/usb/type-c/ucsi.h
>  create mode 100644 drivers/usb/type-c/ucsi_acpi.c
>  create mode 100644 include/linux/usb/typec.h
>
> --
> 2.7.0
>
> --
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