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Message-Id: <20170522200542.27116-1-Badhri@google.com>
Date: Mon, 22 May 2017 13:05:42 -0700
From: Badhri Jagan Sridharan <badhri@...gle.com>
To: Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org,
Guenter Roeck <linux@...ck-us.net>,
Oliver Neukum <oneukum@...e.com>,
Badhri Jagan Sridharan <Badhri@...gle.com>
Subject: [PATCH] usb: typec: Add a sysfs node to manage port type
User space applications in some cases have the need to enforce a
specific port type(DFP/UFP/DRP). This change allows userspace to
attempt setting the desired port type. Low level drivers can
however reject the request if the specific port type is not supported.
Signed-off-by: Badhri Jagan Sridharan <Badhri@...gle.com>
---
Documentation/ABI/testing/sysfs-class-typec | 13 ++++++++++
drivers/usb/typec/typec.c | 40 +++++++++++++++++++++++++++++
include/linux/usb/typec.h | 4 +++
3 files changed, 57 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-class-typec b/Documentation/ABI/testing/sysfs-class-typec
index d4a3d23eb09c..853b2ef73641 100644
--- a/Documentation/ABI/testing/sysfs-class-typec
+++ b/Documentation/ABI/testing/sysfs-class-typec
@@ -73,6 +73,19 @@ Description:
Valid values: source, sink, none (to remove preference)
+What: /sys/class/typec/<port>/port_type
+Date: May 2017
+Description:
+ Indicates the type of the port. This attribute can be used for
+ requesting a change in the port type. Port type change is
+ supported as a synchronous operation, so write(2) to the
+ attribute will not return until the operation has finished.
+
+ Valid values:
+ - DRP
+ - DFP
+ - UFP
+
What: /sys/class/typec/<port>/supported_accessory_modes
Date: April 2017
Contact: Heikki Krogerus <heikki.krogerus@...ux.intel.com>
diff --git a/drivers/usb/typec/typec.c b/drivers/usb/typec/typec.c
index 89e540bb7ff3..684a13bb744d 100644
--- a/drivers/usb/typec/typec.c
+++ b/drivers/usb/typec/typec.c
@@ -789,6 +789,12 @@ static const char * const typec_data_roles[] = {
[TYPEC_HOST] = "host",
};
+static const char * const typec_port_types[] = {
+ [TYPEC_PORT_DFP] = "dfp",
+ [TYPEC_PORT_UFP] = "ufp",
+ [TYPEC_PORT_DRP] = "drp",
+};
+
static ssize_t
preferred_role_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t size)
@@ -926,6 +932,39 @@ static ssize_t power_role_show(struct device *dev,
}
static DEVICE_ATTR_RW(power_role);
+static ssize_t
+port_type_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ struct typec_port *port = to_typec_port(dev);
+ int ret;
+
+ if (!port->cap->port_type_set) {
+ dev_dbg(dev, "changing port type not supported\n");
+ return -EOPNOTSUPP;
+ }
+
+ ret = sysfs_match_string(typec_port_types, buf);
+ if (ret < 0)
+ return ret;
+
+ ret = port->cap->port_type_set(port->cap, ret);
+ if (ret)
+ return ret;
+
+ return size;
+}
+
+static ssize_t
+port_type_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct typec_port *port = to_typec_port(dev);
+
+ return sprintf(buf, "%s\n", typec_port_types[port->cap->type]);
+}
+static DEVICE_ATTR_RW(port_type);
+
static const char * const typec_pwr_opmodes[] = {
[TYPEC_PWR_MODE_USB] = "default",
[TYPEC_PWR_MODE_1_5A] = "1.5A",
@@ -1035,6 +1074,7 @@ static struct attribute *typec_attrs[] = {
&dev_attr_usb_power_delivery_revision.attr,
&dev_attr_usb_typec_revision.attr,
&dev_attr_vconn_source.attr,
+ &dev_attr_port_type.attr,
NULL,
};
ATTRIBUTE_GROUPS(typec);
diff --git a/include/linux/usb/typec.h b/include/linux/usb/typec.h
index ec78204964ab..5badf6f66479 100644
--- a/include/linux/usb/typec.h
+++ b/include/linux/usb/typec.h
@@ -190,6 +190,7 @@ struct typec_partner_desc {
* @pr_set: Set Power Role
* @vconn_set: Set VCONN Role
* @activate_mode: Enter/exit given Alternate Mode
+ * @port_type_set: Set port type
*
* Static capabilities of a single USB Type-C port.
*/
@@ -214,6 +215,9 @@ struct typec_capability {
int (*activate_mode)(const struct typec_capability *,
int mode, int activate);
+
+ int (*port_type_set)(const struct typec_capability *,
+ enum typec_port_type);
};
/* Specific to try_role(). Indicates the user want's to clear the preference. */
--
2.13.0.303.g4ebf302169-goog
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