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From:   Puma Hsu <pumahsu@google.com>
Date:   Wed, 23 Oct 2019 21:53:32 +0800
Message-ID: <CAGCq0La+sM2wtgVzj3WWq0yPUeX1irWY=LpSf7ny71HY3_T23A@mail.gmail.com>
Subject: Re: [PATCH V2] usb: typec: Add sysfs node to show connector orientation
To:     Guenter Roeck <linux@roeck-us.net>
Cc:     Heikki Krogerus <heikki.krogerus@linux.intel.com>,
        gregkh@linuxfoundation.org,
        Badhri Jagan Sridharan <badhri@google.com>,
        Kyle Tso <kyletso@google.com>,
        Albert Wang <albertccwang@google.com>,
        Chien Kun Niu <rickyniu@google.com>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
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Sender: linux-kernel-owner@vger.kernel.org
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Hi Guenter,

I think "unknown" here means that the USB port is disconnected in real usage.

Thanks in advance.
Puma Hsu


On Wed, Oct 23, 2019 at 9:44 PM Guenter Roeck <linux@roeck-us.net> 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 ?
>
> Guenter
>
> >>   USB Type-C partner devices (eg. /sys/class/typec/port0-partner/)
> >>
> >> diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
> >> index 94a3eda62add..911d06676aeb 100644
> >> --- a/drivers/usb/typec/class.c
> >> +++ b/drivers/usb/typec/class.c >> @@ -1245,6 +1245,23 @@ static ssize_t usb_power_delivery_revision_show(struct device *dev,
> >>   }
> >>   static DEVICE_ATTR_RO(usb_power_delivery_revision);
> >>
> >> +static const char * const typec_connector_orientation[] = {
> >> +    [TYPEC_ORIENTATION_NONE]                = "unknown",
> >> +    [TYPEC_ORIENTATION_NORMAL]              = "normal",
> >> +    [TYPEC_ORIENTATION_REVERSE]             = "reversed",
> >> +};
> >> +
> >> +static ssize_t connector_orientation_show(struct device *dev,
> >> +                                            struct device_attribute *attr,
> >> +                                            char *buf)
> >> +{
> >> +    struct typec_port *p = to_typec_port(dev);
> >> +
> >> +    return sprintf(buf, "%s\n",
> >> +                   typec_connector_orientation[p->orientation]);
> >> +}
> >> +static DEVICE_ATTR_RO(connector_orientation);
> >> +
> >>   static struct attribute *typec_attrs[] = {
> >>      &dev_attr_data_role.attr,
> >>      &dev_attr_power_operation_mode.attr,
> >> @@ -1255,6 +1272,7 @@ static struct attribute *typec_attrs[] = {
> >>      &dev_attr_usb_typec_revision.attr,
> >>      &dev_attr_vconn_source.attr,
> >>      &dev_attr_port_type.attr,
> >> +    &dev_attr_connector_orientation.attr,
> >>      NULL,
> >>   };
> >>   ATTRIBUTE_GROUPS(typec);
> >
> > thanks,
> >
>