Date:	Tue,  9 Feb 2016 01:44:11 +0530
From:	Amit Pundir <amit.pundir@...aro.org>
To:	linux-kernel@...r.kernel.org, linux-usb@...r.kernel.org
Cc:	Badhri Jagan Sridharan <Badhri@...gle.com>,
	Felipe Balbi <balbi@...nel.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Android Kernel Team <kernel-team@...roid.com>,
	John Stultz <john.stultz@...aro.org>,
	Sumit Semwal <sumit.semwal@...aro.org>
Subject: [RFC][PATCH] usb: phy: Dual role sysfs class definition

From: Badhri Jagan Sridharan <Badhri@...gle.com>

This CL adds a new class to monitor and change
dual role usb ports from userspace. The usb
phy drivers can register to the dual_role_usb
class and expose the capabilities of the ports.
The phy drivers can decide on whether a specific
attribute can be changed from userspace by
choosing to implement the appropriate callback.

Cc: Felipe Balbi <balbi@...nel.org>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: Android Kernel Team <kernel-team@...roid.com>
Cc: John Stultz <john.stultz@...aro.org>
Cc: Sumit Semwal <sumit.semwal@...aro.org>
Signed-off-by: Badhri Jagan Sridharan <Badhri@...gle.com>
[pundir: cherry-picked this patch from AOSP experimental/android-4.4 tree.]
Signed-off-by: Amit Pundir <amit.pundir@...aro.org>
---
Cherry-picked this patch from AOSP common/experimental/android-4.4 tree.
I could not find upstream submission history for this patch, so my
apologies in advance if this has already been NACKed before.

 .../ABI/testing/sysfs-class-dual-role-usb          |  71 +++
 drivers/usb/phy/Kconfig                            |   9 +
 drivers/usb/phy/Makefile                           |   1 +
 drivers/usb/phy/class-dual-role.c                  | 529 +++++++++++++++++++++
 include/linux/usb/class-dual-role.h                | 128 +++++
 5 files changed, 738 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-class-dual-role-usb
 create mode 100644 drivers/usb/phy/class-dual-role.c
 create mode 100644 include/linux/usb/class-dual-role.h

diff --git a/Documentation/ABI/testing/sysfs-class-dual-role-usb b/Documentation/ABI/testing/sysfs-class-dual-role-usb
new file mode 100644
index 0000000..a900fd7
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-dual-role-usb
@@ -0,0 +1,71 @@
+What:		/sys/class/dual_role_usb/.../
+Date:		June 2015
+Contact:	Badhri Jagan Sridharan<badhri@...gle.com>
+Description:
+		Provide a generic interface to monitor and change
+		the state of dual role usb ports. The name here
+		refers to the name mentioned in the
+		dual_role_phy_desc that is passed while registering
+		the dual_role_phy_intstance through
+		devm_dual_role_instance_register.
+
+What:           /sys/class/dual_role_usb/.../supported_modes
+Date:           June 2015
+Contact:        Badhri Jagan Sridharan<badhri@...gle.com>
+Description:
+		This is a static node, once initialized this
+		is not expected to change during runtime. "dfp"
+		refers to "downstream facing port" i.e. port can
+		only act as host. "ufp" refers to "upstream
+		facing port" i.e. port can only act as device.
+		"dfp ufp" refers to "dual role port" i.e. the port
+		can either be a host port or a device port.
+
+What:		/sys/class/dual_role_usb/.../mode
+Date:		June 2015
+Contact:	Badhri Jagan Sridharan<badhri@...gle.com>
+Description:
+		The mode node refers to the current mode in which the
+		port is operating. "dfp" for host ports. "ufp" for device
+		ports and "none" when cable is not connected.
+
+		On devices where the USB mode is software-controllable,
+		userspace can change the mode by writing "dfp" or "ufp".
+		On devices where the USB mode is fixed in hardware,
+		this attribute is read-only.
+
+What:		/sys/class/dual_role_usb/.../power_role
+Date:		June 2015
+Contact:	Badhri Jagan Sridharan<badhri@...gle.com>
+Description:
+		The power_role node mentions whether the port
+		is "sink"ing or "source"ing power. "none" if
+		they are not connected.
+
+		On devices implementing USB Power Delivery,
+		userspace can control the power role by writing "sink" or
+		"source". On devices without USB-PD, this attribute is
+		read-only.
+
+What:		/sys/class/dual_role_usb/.../data_role
+Date:		June 2015
+Contact:	Badhri Jagan Sridharan<badhri@...gle.com>
+Description:
+		The data_role node mentions whether the port
+		is acting as "host" or "device" for USB data connection.
+		"none" if there is no active data link.
+
+		On devices implementing USB Power Delivery, userspace
+		can control the data role by writing "host" or "device".
+		On devices without USB-PD, this attribute is read-only
+
+What:		/sys/class/dual_role_usb/.../powers_vconn
+Date:		June 2015
+Contact:	Badhri Jagan Sridharan<badhri@...gle.com>
+Description:
+		The powers_vconn node mentions whether the port
+		is supplying power for VCONN pin.
+
+		On devices with software control of VCONN,
+		userspace can disable the power supply to VCONN by writing "n",
+		or enable the power supply by writing "y".
diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
index c690474..24e307b 100644
--- a/drivers/usb/phy/Kconfig
+++ b/drivers/usb/phy/Kconfig
@@ -201,4 +201,13 @@ config USB_ULPI_VIEWPORT
 	  Provides read/write operations to the ULPI phy register set for
 	  controllers with a viewport register (e.g. Chipidea/ARC controllers).
 
+config DUAL_ROLE_USB_INTF
+	bool "Generic DUAL ROLE sysfs interface"
+	depends on SYSFS && USB_PHY
+	help
+	  A generic sysfs interface to track and change the state of
+	  dual role usb phys. The usb phy drivers can register to
+	  this interface to expose it capabilities to the userspace
+	  and thereby allowing userspace to change the port mode.
+
 endmenu
diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
index b433e5d..925ff2d 100644
--- a/drivers/usb/phy/Makefile
+++ b/drivers/usb/phy/Makefile
@@ -3,6 +3,7 @@
 #
 obj-$(CONFIG_USB_PHY)			+= phy.o
 obj-$(CONFIG_OF)			+= of.o
+obj-$(CONFIG_DUAL_ROLE_USB_INTF)	+= class-dual-role.o
 
 # transceiver drivers, keep the list sorted
 
diff --git a/drivers/usb/phy/class-dual-role.c b/drivers/usb/phy/class-dual-role.c
new file mode 100644
index 0000000..e922df5
--- /dev/null
+++ b/drivers/usb/phy/class-dual-role.c
@@ -0,0 +1,529 @@
+/*
+ * class-dual-role.c
+ *
+ * Copyright (C) 2015 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/ctype.h>
+#include <linux/device.h>
+#include <linux/usb/class-dual-role.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/stat.h>
+#include <linux/types.h>
+
+#define DUAL_ROLE_NOTIFICATION_TIMEOUT 2000
+
+static ssize_t dual_role_store_property(struct device *dev,
+					struct device_attribute *attr,
+					const char *buf, size_t count);
+static ssize_t dual_role_show_property(struct device *dev,
+				       struct device_attribute *attr,
+				       char *buf);
+
+#define DUAL_ROLE_ATTR(_name)				\
+{							\
+	.attr = { .name = #_name },			\
+	.show = dual_role_show_property,		\
+	.store = dual_role_store_property,		\
+}
+
+static struct device_attribute dual_role_attrs[] = {
+	DUAL_ROLE_ATTR(supported_modes),
+	DUAL_ROLE_ATTR(mode),
+	DUAL_ROLE_ATTR(power_role),
+	DUAL_ROLE_ATTR(data_role),
+	DUAL_ROLE_ATTR(powers_vconn),
+};
+
+struct class *dual_role_class;
+EXPORT_SYMBOL_GPL(dual_role_class);
+
+static struct device_type dual_role_dev_type;
+
+static char *kstrdupcase(const char *str, gfp_t gfp, bool to_upper)
+{
+	char *ret, *ustr;
+
+	ustr = ret = kmalloc(strlen(str) + 1, gfp);
+
+	if (!ret)
+		return NULL;
+
+	while (*str)
+		*ustr++ = to_upper ? toupper(*str++) : tolower(*str++);
+
+	*ustr = 0;
+
+	return ret;
+}
+
+static void dual_role_changed_work(struct work_struct *work)
+{
+	struct dual_role_phy_instance *dual_role =
+	    container_of(work, struct dual_role_phy_instance,
+			 changed_work);
+
+	dev_dbg(&dual_role->dev, "%s\n", __func__);
+	kobject_uevent(&dual_role->dev.kobj, KOBJ_CHANGE);
+}
+
+void dual_role_instance_changed(struct dual_role_phy_instance *dual_role)
+{
+	dev_dbg(&dual_role->dev, "%s\n", __func__);
+	pm_wakeup_event(&dual_role->dev, DUAL_ROLE_NOTIFICATION_TIMEOUT);
+	schedule_work(&dual_role->changed_work);
+}
+EXPORT_SYMBOL_GPL(dual_role_instance_changed);
+
+int dual_role_get_property(struct dual_role_phy_instance *dual_role,
+			   enum dual_role_property prop,
+			   unsigned int *val)
+{
+	return dual_role->desc->get_property(dual_role, prop, val);
+}
+EXPORT_SYMBOL_GPL(dual_role_get_property);
+
+int dual_role_set_property(struct dual_role_phy_instance *dual_role,
+			   enum dual_role_property prop,
+			   const unsigned int *val)
+{
+	if (!dual_role->desc->set_property)
+		return -ENODEV;
+
+	return dual_role->desc->set_property(dual_role, prop, val);
+}
+EXPORT_SYMBOL_GPL(dual_role_set_property);
+
+int dual_role_property_is_writeable(struct dual_role_phy_instance *dual_role,
+				    enum dual_role_property prop)
+{
+	if (!dual_role->desc->property_is_writeable)
+		return -ENODEV;
+
+	return dual_role->desc->property_is_writeable(dual_role, prop);
+}
+EXPORT_SYMBOL_GPL(dual_role_property_is_writeable);
+
+static void dual_role_dev_release(struct device *dev)
+{
+	struct dual_role_phy_instance *dual_role =
+	    container_of(dev, struct dual_role_phy_instance, dev);
+	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
+	kfree(dual_role);
+}
+
+static struct dual_role_phy_instance *__must_check
+__dual_role_register(struct device *parent,
+		     const struct dual_role_phy_desc *desc)
+{
+	struct device *dev;
+	struct dual_role_phy_instance *dual_role;
+	int rc;
+
+	dual_role = kzalloc(sizeof(*dual_role), GFP_KERNEL);
+	if (!dual_role)
+		return ERR_PTR(-ENOMEM);
+
+	dev = &dual_role->dev;
+
+	device_initialize(dev);
+
+	dev->class = dual_role_class;
+	dev->type = &dual_role_dev_type;
+	dev->parent = parent;
+	dev->release = dual_role_dev_release;
+	dev_set_drvdata(dev, dual_role);
+	dual_role->desc = desc;
+
+	rc = dev_set_name(dev, "%s", desc->name);
+	if (rc)
+		goto dev_set_name_failed;
+
+	INIT_WORK(&dual_role->changed_work, dual_role_changed_work);
+
+	rc = device_init_wakeup(dev, true);
+	if (rc)
+		goto wakeup_init_failed;
+
+	rc = device_add(dev);
+	if (rc)
+		goto device_add_failed;
+
+	dual_role_instance_changed(dual_role);
+
+	return dual_role;
+
+device_add_failed:
+	device_init_wakeup(dev, false);
+wakeup_init_failed:
+dev_set_name_failed:
+	put_device(dev);
+	kfree(dual_role);
+
+	return ERR_PTR(rc);
+}
+
+static void dual_role_instance_unregister(struct dual_role_phy_instance
+					  *dual_role)
+{
+	cancel_work_sync(&dual_role->changed_work);
+	device_init_wakeup(&dual_role->dev, false);
+	device_unregister(&dual_role->dev);
+}
+
+static void devm_dual_role_release(struct device *dev, void *res)
+{
+	struct dual_role_phy_instance **dual_role = res;
+
+	dual_role_instance_unregister(*dual_role);
+}
+
+struct dual_role_phy_instance *__must_check
+devm_dual_role_instance_register(struct device *parent,
+				 const struct dual_role_phy_desc *desc)
+{
+	struct dual_role_phy_instance **ptr, *dual_role;
+
+	ptr = devres_alloc(devm_dual_role_release, sizeof(*ptr), GFP_KERNEL);
+
+	if (!ptr)
+		return ERR_PTR(-ENOMEM);
+	dual_role = __dual_role_register(parent, desc);
+	if (IS_ERR(dual_role)) {
+		devres_free(ptr);
+	} else {
+		*ptr = dual_role;
+		devres_add(parent, ptr);
+	}
+	return dual_role;
+}
+EXPORT_SYMBOL_GPL(devm_dual_role_instance_register);
+
+static int devm_dual_role_match(struct device *dev, void *res, void *data)
+{
+	struct dual_role_phy_instance **r = res;
+
+	if (WARN_ON(!r || !*r))
+		return 0;
+
+	return *r == data;
+}
+
+void devm_dual_role_instance_unregister(struct device *dev,
+					struct dual_role_phy_instance
+					*dual_role)
+{
+	int rc;
+
+	rc = devres_release(dev, devm_dual_role_release,
+			    devm_dual_role_match, dual_role);
+	WARN_ON(rc);
+}
+EXPORT_SYMBOL_GPL(devm_dual_role_instance_unregister);
+
+void *dual_role_get_drvdata(struct dual_role_phy_instance *dual_role)
+{
+	return dual_role->drv_data;
+}
+EXPORT_SYMBOL_GPL(dual_role_get_drvdata);
+
+/***************** Device attribute functions **************************/
+
+/* port type */
+static char *supported_modes_text[] = {
+	"ufp dfp", "dfp", "ufp"
+};
+
+/* current mode */
+static char *mode_text[] = {
+	"ufp", "dfp", "none"
+};
+
+/* Power role */
+static char *pr_text[] = {
+	"source", "sink", "none"
+};
+
+/* Data role */
+static char *dr_text[] = {
+	"host", "device", "none"
+};
+
+/* Vconn supply */
+static char *vconn_supply_text[] = {
+	"n", "y"
+};
+
+static ssize_t dual_role_show_property(struct device *dev,
+				       struct device_attribute *attr, char *buf)
+{
+	ssize_t ret = 0;
+	struct dual_role_phy_instance *dual_role = dev_get_drvdata(dev);
+	const ptrdiff_t off = attr - dual_role_attrs;
+	unsigned int value;
+
+	if (off == DUAL_ROLE_PROP_SUPPORTED_MODES) {
+		value = dual_role->desc->supported_modes;
+	} else {
+		ret = dual_role_get_property(dual_role, off, &value);
+
+		if (ret < 0) {
+			if (ret == -ENODATA)
+				dev_dbg(dev,
+					"driver has no data for `%s' property\n",
+					attr->attr.name);
+			else if (ret != -ENODEV)
+				dev_err(dev,
+					"driver failed to report `%s' property: %zd\n",
+					attr->attr.name, ret);
+			return ret;
+		}
+	}
+
+	if (off == DUAL_ROLE_PROP_SUPPORTED_MODES) {
+		BUILD_BUG_ON(DUAL_ROLE_PROP_SUPPORTED_MODES_TOTAL !=
+			ARRAY_SIZE(supported_modes_text));
+		if (value < DUAL_ROLE_PROP_SUPPORTED_MODES_TOTAL)
+			return snprintf(buf, PAGE_SIZE, "%s\n",
+					supported_modes_text[value]);
+		else
+			return -EIO;
+	} else if (off == DUAL_ROLE_PROP_MODE) {
+		BUILD_BUG_ON(DUAL_ROLE_PROP_MODE_TOTAL !=
+			ARRAY_SIZE(mode_text));
+		if (value < DUAL_ROLE_PROP_MODE_TOTAL)
+			return snprintf(buf, PAGE_SIZE, "%s\n",
+					mode_text[value]);
+		else
+			return -EIO;
+	} else if (off == DUAL_ROLE_PROP_PR) {
+		BUILD_BUG_ON(ARRAY_SIZE(pr_text) != DUAL_ROLE_PROP_PR_TOTAL);
+		if (value < DUAL_ROLE_PROP_PR_TOTAL)
+			return snprintf(buf, PAGE_SIZE, "%s\n",
+					pr_text[value]);
+		else
+			return -EIO;
+	} else if (off == DUAL_ROLE_PROP_DR) {
+		BUILD_BUG_ON(ARRAY_SIZE(dr_text) != DUAL_ROLE_PROP_DR_TOTAL);
+		if (value < DUAL_ROLE_PROP_DR_TOTAL)
+			return snprintf(buf, PAGE_SIZE, "%s\n",
+					dr_text[value]);
+		else
+			return -EIO;
+	} else if (off == DUAL_ROLE_PROP_VCONN_SUPPLY) {
+		BUILD_BUG_ON(DUAL_ROLE_PROP_VCONN_SUPPLY_TOTAL !=
+				ARRAY_SIZE(vconn_supply_text));
+		if (value < DUAL_ROLE_PROP_VCONN_SUPPLY_TOTAL)
+			return snprintf(buf, PAGE_SIZE, "%s\n",
+					vconn_supply_text[value]);
+		else
+			return -EIO;
+	} else
+		return -EIO;
+}
+
+static ssize_t dual_role_store_property(struct device *dev,
+					struct device_attribute *attr,
+					const char *buf, size_t count)
+{
+	ssize_t ret;
+	struct dual_role_phy_instance *dual_role = dev_get_drvdata(dev);
+	const ptrdiff_t off = attr - dual_role_attrs;
+	unsigned int value;
+	int total, i;
+	char *dup_buf, **text_array;
+	bool result = false;
+
+	dup_buf = kstrdupcase(buf, GFP_KERNEL, false);
+	switch (off) {
+	case DUAL_ROLE_PROP_MODE:
+		total = DUAL_ROLE_PROP_MODE_TOTAL;
+		text_array = mode_text;
+		break;
+	case DUAL_ROLE_PROP_PR:
+		total = DUAL_ROLE_PROP_PR_TOTAL;
+		text_array = pr_text;
+		break;
+	case DUAL_ROLE_PROP_DR:
+		total = DUAL_ROLE_PROP_DR_TOTAL;
+		text_array = dr_text;
+		break;
+	case DUAL_ROLE_PROP_VCONN_SUPPLY:
+		ret = strtobool(dup_buf, &result);
+		value = result;
+		if (!ret)
+			goto setprop;
+	default:
+		ret = -EINVAL;
+		goto error;
+	}
+
+	for (i = 0; i <= total; i++) {
+		if (i == total) {
+			ret = -ENOTSUPP;
+			goto error;
+		}
+		if (!strncmp(*(text_array + i), dup_buf,
+			     strlen(*(text_array + i)))) {
+			value = i;
+			break;
+		}
+	}
+
+setprop:
+	ret = dual_role->desc->set_property(dual_role, off, &value);
+
+error:
+	kfree(dup_buf);
+
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static umode_t dual_role_attr_is_visible(struct kobject *kobj,
+					 struct attribute *attr, int attrno)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct dual_role_phy_instance *dual_role = dev_get_drvdata(dev);
+	umode_t mode = S_IRUSR | S_IRGRP | S_IROTH;
+	int i;
+
+	if (attrno == DUAL_ROLE_PROP_SUPPORTED_MODES)
+		return mode;
+
+	for (i = 0; i < dual_role->desc->num_properties; i++) {
+		int property = dual_role->desc->properties[i];
+
+		if (property == attrno) {
+			if (dual_role->desc->property_is_writeable &&
+			    dual_role_property_is_writeable(dual_role, property)
+			    > 0)
+				mode |= S_IWUSR;
+
+			return mode;
+		}
+	}
+
+	return 0;
+}
+
+static struct attribute *__dual_role_attrs[ARRAY_SIZE(dual_role_attrs) + 1];
+
+static struct attribute_group dual_role_attr_group = {
+	.attrs = __dual_role_attrs,
+	.is_visible = dual_role_attr_is_visible,
+};
+
+static const struct attribute_group *dual_role_attr_groups[] = {
+	&dual_role_attr_group,
+	NULL,
+};
+
+void dual_role_init_attrs(struct device_type *dev_type)
+{
+	int i;
+
+	dev_type->groups = dual_role_attr_groups;
+
+	for (i = 0; i < ARRAY_SIZE(dual_role_attrs); i++)
+		__dual_role_attrs[i] = &dual_role_attrs[i].attr;
+}
+
+int dual_role_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	struct dual_role_phy_instance *dual_role = dev_get_drvdata(dev);
+	int ret = 0, j;
+	char *prop_buf;
+	char *attrname;
+
+	dev_dbg(dev, "uevent\n");
+
+	if (!dual_role || !dual_role->desc) {
+		dev_dbg(dev, "No dual_role phy yet\n");
+		return ret;
+	}
+
+	dev_dbg(dev, "DUAL_ROLE_NAME=%s\n", dual_role->desc->name);
+
+	ret = add_uevent_var(env, "DUAL_ROLE_NAME=%s", dual_role->desc->name);
+	if (ret)
+		return ret;
+
+	prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
+	if (!prop_buf)
+		return -ENOMEM;
+
+	for (j = 0; j < dual_role->desc->num_properties; j++) {
+		struct device_attribute *attr;
+		char *line;
+
+		attr = &dual_role_attrs[dual_role->desc->properties[j]];
+
+		ret = dual_role_show_property(dev, attr, prop_buf);
+		if (ret == -ENODEV || ret == -ENODATA) {
+			ret = 0;
+			continue;
+		}
+
+		if (ret < 0)
+			goto out;
+		line = strnchr(prop_buf, PAGE_SIZE, '\n');
+		if (line)
+			*line = 0;
+
+		attrname = kstrdupcase(attr->attr.name, GFP_KERNEL, true);
+		if (!attrname)
+			ret = -ENOMEM;
+
+		dev_dbg(dev, "prop %s=%s\n", attrname, prop_buf);
+
+		ret = add_uevent_var(env, "DUAL_ROLE_%s=%s", attrname,
+				     prop_buf);
+		kfree(attrname);
+		if (ret)
+			goto out;
+	}
+
+out:
+	free_page((unsigned long)prop_buf);
+
+	return ret;
+}
+
+/******************* Module Init ***********************************/
+
+static int __init dual_role_class_init(void)
+{
+	dual_role_class = class_create(THIS_MODULE, "dual_role_usb");
+
+	if (IS_ERR(dual_role_class))
+		return PTR_ERR(dual_role_class);
+
+	dual_role_class->dev_uevent = dual_role_uevent;
+	dual_role_init_attrs(&dual_role_dev_type);
+
+	return 0;
+}
+
+static void __exit dual_role_class_exit(void)
+{
+	class_destroy(dual_role_class);
+}
+
+subsys_initcall(dual_role_class_init);
+module_exit(dual_role_class_exit);
diff --git a/include/linux/usb/class-dual-role.h b/include/linux/usb/class-dual-role.h
new file mode 100644
index 0000000..b0c859c
--- /dev/null
+++ b/include/linux/usb/class-dual-role.h
@@ -0,0 +1,128 @@
+#ifndef __LINUX_CLASS_DUAL_ROLE_H__
+#define __LINUX_CLASS_DUAL_ROLE_H__
+
+#include <linux/workqueue.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+
+struct device;
+
+enum dual_role_supported_modes {
+	DUAL_ROLE_SUPPORTED_MODES_DFP_AND_UFP = 0,
+	DUAL_ROLE_SUPPORTED_MODES_DFP,
+	DUAL_ROLE_SUPPORTED_MODES_UFP,
+/*The following should be the last element*/
+	DUAL_ROLE_PROP_SUPPORTED_MODES_TOTAL,
+};
+
+enum {
+	DUAL_ROLE_PROP_MODE_UFP = 0,
+	DUAL_ROLE_PROP_MODE_DFP,
+	DUAL_ROLE_PROP_MODE_NONE,
+/*The following should be the last element*/
+	DUAL_ROLE_PROP_MODE_TOTAL,
+};
+
+enum {
+	DUAL_ROLE_PROP_PR_SRC = 0,
+	DUAL_ROLE_PROP_PR_SNK,
+	DUAL_ROLE_PROP_PR_NONE,
+/*The following should be the last element*/
+	DUAL_ROLE_PROP_PR_TOTAL,
+
+};
+
+enum {
+	DUAL_ROLE_PROP_DR_HOST = 0,
+	DUAL_ROLE_PROP_DR_DEVICE,
+	DUAL_ROLE_PROP_DR_NONE,
+/*The following should be the last element*/
+	DUAL_ROLE_PROP_DR_TOTAL,
+};
+
+enum {
+	DUAL_ROLE_PROP_VCONN_SUPPLY_NO = 0,
+	DUAL_ROLE_PROP_VCONN_SUPPLY_YES,
+/*The following should be the last element*/
+	DUAL_ROLE_PROP_VCONN_SUPPLY_TOTAL,
+};
+
+enum dual_role_property {
+	DUAL_ROLE_PROP_SUPPORTED_MODES = 0,
+	DUAL_ROLE_PROP_MODE,
+	DUAL_ROLE_PROP_PR,
+	DUAL_ROLE_PROP_DR,
+	DUAL_ROLE_PROP_VCONN_SUPPLY,
+};
+
+struct dual_role_phy_instance;
+
+/* Description of typec port */
+struct dual_role_phy_desc {
+	/* /sys/class/dual_role_usb/<name>/ */
+	const char *name;
+	enum dual_role_supported_modes supported_modes;
+	enum dual_role_property *properties;
+	size_t num_properties;
+
+	/* Callback for "cat /sys/class/dual_role_usb/<name>/<property>" */
+	int (*get_property)(struct dual_role_phy_instance *dual_role,
+			     enum dual_role_property prop,
+			     unsigned int *val);
+	/* Callback for
+	 * "echo <value> > /sys/class/dual_role_usb/<name>/<property>"
+	 */
+	int (*set_property)(struct dual_role_phy_instance *dual_role,
+			     enum dual_role_property prop,
+			     const unsigned int *val);
+	/* Decides whether userspace can change a specific property */
+	int (*property_is_writeable)(struct dual_role_phy_instance *dual_role,
+				      enum dual_role_property prop);
+};
+
+struct dual_role_phy_instance {
+	const struct dual_role_phy_desc *desc;
+
+	/* Driver private data */
+	void *drv_data;
+
+	struct device dev;
+	struct work_struct changed_work;
+};
+
+#if IS_ENABLED(CONFIG_DUAL_ROLE_USB_INTF)
+extern void dual_role_instance_changed(struct dual_role_phy_instance
+				       *dual_role);
+extern struct dual_role_phy_instance *__must_check
+devm_dual_role_instance_register(struct device *parent,
+				 const struct dual_role_phy_desc *desc);
+extern void devm_dual_role_instance_unregister(struct device *dev,
+					       struct dual_role_phy_instance
+					       *dual_role);
+extern int dual_role_get_property(struct dual_role_phy_instance *dual_role,
+				  enum dual_role_property prop,
+				  unsigned int *val);
+extern int dual_role_set_property(struct dual_role_phy_instance *dual_role,
+				  enum dual_role_property prop,
+				  const unsigned int *val);
+extern int dual_role_property_is_writeable(struct dual_role_phy_instance
+					   *dual_role,
+					   enum dual_role_property prop);
+extern void *dual_role_get_drvdata(struct dual_role_phy_instance *dual_role);
+#else /* CONFIG_DUAL_ROLE_USB_INTF */
+static void dual_role_instance_changed(struct dual_role_phy_instance
+				       *dual_role){}
+static struct dual_role_phy_instance *__must_check
+devm_dual_role_instance_register(struct device *parent,
+				 const struct dual_role_phy_desc *desc)
+{
+	return ERR_PTR(-ENOSYS);
+}
+static void devm_dual_role_instance_unregister(struct device *dev,
+					       struct dual_role_phy_instance
+					       *dual_role){}
+static void *dual_role_get_drvdata(struct dual_role_phy_instance *dual_role)
+{
+	return ERR_PTR(-ENOSYS);
+}
+#endif /* CONFIG_DUAL_ROLE_USB_INTF */
-- 
1.9.1

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