usb: typec: Bus type for alternate modes

Introducing a simple bus for the alternate modes. Bus allows
binding drivers to the discovered alternate modes the
partners support.

Signed-off-by: Heikki Krogerus <[e-mail]>
Tested-by: Hans de Goede <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/ABI/obsolete/sysfs-class-typec

···
+These files are deprecated and will be removed. The same files are available
+under /sys/bus/typec (see Documentation/ABI/testing/sysfs-bus-typec).
+
+What:		/sys/class/typec/<port|partner|cable>/<dev>/svid
+Date:		April 2017
+Contact:	Heikki Krogerus <[e-mail]>
+Description:
+		The SVID (Standard or Vendor ID) assigned by USB-IF for this
+		alternate mode.
+
+What:		/sys/class/typec/<port|partner|cable>/<dev>/mode<index>/
+Date:		April 2017
+Contact:	Heikki Krogerus <[e-mail]>
+Description:
+		Every supported mode will have its own directory. The name of
+		a mode will be "mode<index>" (for example mode1), where <index>
+		is the actual index to the mode VDO returned by Discover Modes
+		USB power delivery command.
+
+What:		/sys/class/typec/<port|partner|cable>/<dev>/mode<index>/description
+Date:		April 2017
+Contact:	Heikki Krogerus <[e-mail]>
+Description:
+		Shows description of the mode. The description is optional for
+		the drivers, just like with the Billboard Devices.
+
+What:		/sys/class/typec/<port|partner|cable>/<dev>/mode<index>/vdo
+Date:		April 2017
+Contact:	Heikki Krogerus <[e-mail]>
+Description:
+		Shows the VDO in hexadecimal returned by Discover Modes command
+		for this mode.
+
+What:		/sys/class/typec/<port|partner|cable>/<dev>/mode<index>/active
+Date:		April 2017
+Contact:	Heikki Krogerus <[e-mail]>
+Description:
+		Shows if the mode is active or not. The attribute can be used
+		for entering/exiting the mode with partners and cable plugs, and
+		with the port alternate modes it can be used for disabling
+		support for specific alternate modes. Entering/exiting modes is
+		supported as synchronous operation so write(2) to the attribute
+		does not return until the enter/exit mode operation has
+		finished. The attribute is notified when the mode is
+		entered/exited so poll(2) on the attribute wakes up.
+		Entering/exiting a mode will also generate uevent KOBJ_CHANGE.
+
+		Valid values: yes, no

Documentation/ABI/testing/sysfs-bus-typec

···
+What:		/sys/bus/typec/devices/.../active
+Date:		July 2018
+Contact:	Heikki Krogerus <[e-mail]>
+Description:
+		Shows if the mode is active or not. The attribute can be used
+		for entering/exiting the mode. Entering/exiting modes is
+		supported as synchronous operation so write(2) to the attribute
+		does not return until the enter/exit mode operation has
+		finished. The attribute is notified when the mode is
+		entered/exited so poll(2) on the attribute wakes up.
+		Entering/exiting a mode will also generate uevent KOBJ_CHANGE.
+
+		Valid values are boolean.
+
+What:		/sys/bus/typec/devices/.../description
+Date:		July 2018
+Contact:	Heikki Krogerus <[e-mail]>
+Description:
+		Shows description of the mode. The description is optional for
+		the drivers, just like with the Billboard Devices.
+
+What:		/sys/bus/typec/devices/.../mode
+Date:		July 2018
+Contact:	Heikki Krogerus <[e-mail]>
+Description:
+		The index number of the mode returned by Discover Modes USB
+		Power Delivery command. Depending on the alternate mode, the
+		mode index may be significant.
+
+		With some alternate modes (SVIDs), the mode index is assigned
+		for specific functionality in the specification for that
+		alternate mode.
+
+		With other alternate modes, the mode index values are not
+		assigned, and can not be therefore used for identification. When
+		the mode index is not assigned, identifying the alternate mode
+		must be done with either mode VDO or the description.
+
+What:		/sys/bus/typec/devices/.../svid
+Date:		July 2018
+Contact:	Heikki Krogerus <[e-mail]>
+Description:
+		The Standard or Vendor ID (SVID) assigned by USB-IF for this
+		alternate mode.
+
+What:		/sys/bus/typec/devices/.../vdo
+Date:		July 2018
+Contact:	Heikki Krogerus <[e-mail]>
+Description:
+		Shows the VDO in hexadecimal returned by Discover Modes command
+		for this mode.

Documentation/ABI/testing/sysfs-class-typec

···
 		available. The value can be polled.
 
 
-Alternate Mode devices.
+USB Type-C port alternate mode devices.
 
-The alternate modes will have Standard or Vendor ID (SVID) assigned by USB-IF.
-The ports, partners and cable plugs can have alternate modes. A supported SVID
-will consist of a set of modes. Every SVID a port/partner/plug supports will
-have a device created for it, and every supported mode for a supported SVID will
-have its own directory under that device. Below <dev> refers to the device for
-the alternate mode.
-
-What:		/sys/class/typec/<port|partner|cable>/<dev>/svid
-Date:		April 2017
-Contact:	Heikki Krogerus <[e-mail]>
-Description:
-		The SVID (Standard or Vendor ID) assigned by USB-IF for this
-		alternate mode.
-
-What:		/sys/class/typec/<port|partner|cable>/<dev>/mode<index>/
-Date:		April 2017
-Contact:	Heikki Krogerus <[e-mail]>
-Description:
-		Every supported mode will have its own directory. The name of
-		a mode will be "mode<index>" (for example mode1), where <index>
-		is the actual index to the mode VDO returned by Discover Modes
-		USB power delivery command.
-
-What:		/sys/class/typec/<port|partner|cable>/<dev>/mode<index>/description
-Date:		April 2017
-Contact:	Heikki Krogerus <[e-mail]>
-Description:
-		Shows description of the mode. The description is optional for
-		the drivers, just like with the Billboard Devices.
-
-What:		/sys/class/typec/<port|partner|cable>/<dev>/mode<index>/vdo
-Date:		April 2017
-Contact:	Heikki Krogerus <[e-mail]>
-Description:
-		Shows the VDO in hexadecimal returned by Discover Modes command
-		for this mode.
-
-What:		/sys/class/typec/<port|partner|cable>/<dev>/mode<index>/active
-Date:		April 2017
-Contact:	Heikki Krogerus <[e-mail]>
-Description:
-		Shows if the mode is active or not. The attribute can be used
-		for entering/exiting the mode with partners and cable plugs, and
-		with the port alternate modes it can be used for disabling
-		support for specific alternate modes. Entering/exiting modes is
-		supported as synchronous operation so write(2) to the attribute
-		does not return until the enter/exit mode operation has
-		finished. The attribute is notified when the mode is
-		entered/exited so poll(2) on the attribute wakes up.
-		Entering/exiting a mode will also generate uevent KOBJ_CHANGE.
-
-		Valid values: yes, no
-
-What:		/sys/class/typec/<port>/<dev>/mode<index>/supported_roles
+What:		/sys/class/typec/<port>/<alt mode>/supported_roles
 Date:		April 2017
 Contact:	Heikki Krogerus <[e-mail]>
 Description:
 		Space separated list of the supported roles.
-
-		This attribute is available for the devices describing the
-		alternate modes a port supports, and it will not be exposed with
-		the devices presenting the alternate modes the partners or cable
-		plugs support.
 
 		Valid values: source, sink

Documentation/driver-api/usb/typec_bus.rst

···
+
+API for USB Type-C Alternate Mode drivers
+=========================================
+
+Introduction
+------------
+
+Alternate modes require communication with the partner using Vendor Defined
+Messages (VDM) as defined in USB Type-C and USB Power Delivery Specifications.
+The communication is SVID (Standard or Vendor ID) specific, i.e. specific for
+every alternate mode, so every alternate mode will need a custom driver.
+
+USB Type-C bus allows binding a driver to the discovered partner alternate
+modes by using the SVID and the mode number.
+
+USB Type-C Connector Class provides a device for every alternate mode a port
+supports, and separate device for every alternate mode the partner supports.
+The drivers for the alternate modes are bound to the partner alternate mode
+devices, and the port alternate mode devices must be handled by the port
+drivers.
+
+When a new partner alternate mode device is registered, it is linked to the
+alternate mode device of the port that the partner is attached to, that has
+matching SVID and mode. Communication between the port driver and alternate mode
+driver will happen using the same API.
+
+The port alternate mode devices are used as a proxy between the partner and the
+alternate mode drivers, so the port drivers are only expected to pass the SVID
+specific commands from the alternate mode drivers to the partner, and from the
+partners to the alternate mode drivers. No direct SVID specific communication is
+needed from the port drivers, but the port drivers need to provide the operation
+callbacks for the port alternate mode devices, just like the alternate mode
+drivers need to provide them for the partner alternate mode devices.
+
+Usage:
+------
+
+General
+~~~~~~~
+
+By default, the alternate mode drivers are responsible for entering the mode.
+It is also possible to leave the decision about entering the mode to the user
+space (See Documentation/ABI/testing/sysfs-class-typec). Port drivers should not
+enter any modes on their own.
+
+``->vdm`` is the most important callback in the operation callbacks vector. It
+will be used to deliver all the SVID specific commands from the partner to the
+alternate mode driver, and vice versa in case of port drivers. The drivers send
+the SVID specific commands to each other using :c:func:`typec_altmode_vmd()`.
+
+If the communication with the partner using the SVID specific commands results
+in need to reconfigure the pins on the connector, the alternate mode driver
+needs to notify the bus using :c:func:`typec_altmode_notify()`. The driver
+passes the negotiated SVID specific pin configuration value to the function as
+parameter. The bus driver will then configure the mux behind the connector using
+that value as the state value for the mux, and also call blocking notification
+chain to notify the external drivers about the state of the connector that need
+to know it.
+
+NOTE: The SVID specific pin configuration values must always start from
+``TYPEC_STATE_MODAL``. USB Type-C specification defines two default states for
+the connector: ``TYPEC_STATE_USB`` and ``TYPEC_STATE_SAFE``. These values are
+reserved by the bus as the first possible values for the state. When the
+alternate mode is entered, the bus will put the connector into
+``TYPEC_STATE_SAFE`` before sending Enter or Exit Mode command as defined in USB
+Type-C Specification, and also put the connector back to ``TYPEC_STATE_USB``
+after the mode has been exited.
+
+An example of working definitions for SVID specific pin configurations would
+look like this:
+
+enum {
+	ALTMODEX_CONF_A = TYPEC_STATE_MODAL,
+	ALTMODEX_CONF_B,
+	...
+};
+
+Helper macro ``TYPEC_MODAL_STATE()`` can also be used:
+
+#define ALTMODEX_CONF_A = TYPEC_MODAL_STATE(0);
+#define ALTMODEX_CONF_B = TYPEC_MODAL_STATE(1);
+
+Notification chain
+~~~~~~~~~~~~~~~~~~
+
+The drivers for the components that the alternate modes are designed for need to
+get details regarding the results of the negotiation with the partner, and the
+pin configuration of the connector. In case of DisplayPort alternate mode for
+example, the GPU drivers will need to know those details. In case of
+Thunderbolt alternate mode, the thunderbolt drivers will need to know them, and
+so on.
+
+The notification chain is designed for this purpose. The drivers can register
+notifiers with :c:func:`typec_altmode_register_notifier()`.
+
+Cable plug alternate modes
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The alternate mode drivers are not bound to cable plug alternate mode devices,
+only to the partner alternate mode devices. If the alternate mode supports, or
+requires, a cable that responds to SOP Prime, and optionally SOP Double Prime
+messages, the driver for that alternate mode must request handle to the cable
+plug alternate modes using :c:func:`typec_altmode_get_plug()`, and take over
+their control.
+
+Driver API
+----------
+
+Alternate mode driver registering/unregistering
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: drivers/usb/typec/bus.c
+   :functions: typec_altmode_register_driver typec_altmode_unregister_driver
+
+Alternate mode driver operations
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: drivers/usb/typec/bus.c
+   :functions: typec_altmode_enter typec_altmode_exit typec_altmode_attention typec_altmode_vdm typec_altmode_notify
+
+API for the port drivers
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: drivers/usb/typec/bus.c
+   :functions: typec_match_altmode
+
+Cable Plug operations
+~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: drivers/usb/typec/bus.c
+   :functions: typec_altmode_get_plug typec_altmode_put_plug
+
+Notifications
+~~~~~~~~~~~~~
+.. kernel-doc:: drivers/usb/typec/class.c
+   :functions: typec_altmode_register_notifier typec_altmode_unregister_notifier

MAINTAINERS

···
 S:	Maintained
 F:	drivers/usb/typec/mux/pi3usb30532.c
 
-USB TYPEC SUBSYSTEM
+USB TYPEC CLASS
 M:	Heikki Krogerus <[e-mail]>
 L:	[e-mail]
 S:	Maintained
···
 F:	Documentation/driver-api/usb/typec.rst
 F:	drivers/usb/typec/
 F:	include/linux/usb/typec.h
+
+USB TYPEC BUS FOR ALTERNATE MODES
+M:	Heikki Krogerus <[e-mail]>
+L:	[e-mail]
+S:	Maintained
+F:	Documentation/ABI/testing/sysfs-bus-typec
+F:	Documentation/driver-api/usb/typec_bus.rst
+F:	drivers/usb/typec/altmodes/
+F:	include/linux/usb/typec_altmode.h
 
 USB UHCI DRIVER
 M:	Alan Stern <[e-mail]>

drivers/usb/typec/Makefile

···
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_TYPEC)		+= typec.o
-typec-y				:= class.o mux.o
+typec-y				:= class.o mux.o bus.o
 obj-$(CONFIG_TYPEC_TCPM)	+= tcpm.o
 obj-y				+= fusb302/
 obj-$(CONFIG_TYPEC_WCOVE)	+= typec_wcove.o

drivers/usb/typec/bus.c

···
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * Bus for USB Type-C Alternate Modes
+ *
+ * Copyright (C) 2018 Intel Corporation
+ * Author: Heikki Krogerus <[e-mail]>
+ */
+
+#include <linux/usb/pd_vdo.h>
+
+#include "bus.h"
+
+static inline int typec_altmode_set_mux(struct altmode *alt, u8 state)
+{
+	return alt->mux ? alt->mux->set(alt->mux, state) : 0;
+}
+
+static int typec_altmode_set_state(struct typec_altmode *adev, int state)
+{
+	bool is_port = is_typec_port(adev->dev.parent);
+	struct altmode *port_altmode;
+	int ret;
+
+	port_altmode = is_port ? to_altmode(adev) : to_altmode(adev)->partner;
+
+	ret = typec_altmode_set_mux(port_altmode, state);
+	if (ret)
+		return ret;
+
+	blocking_notifier_call_chain(&port_altmode->nh, state, NULL);
+
+	return 0;
+}
+
+/* -------------------------------------------------------------------------- */
+/* Common API */
+
+/**
+ * typec_altmode_notify - Communication between the OS and alternate mode driver
+ * @adev: Handle to the alternate mode
+ * @conf: Alternate mode specific configuration value
+ * @data: Alternate mode specific data
+ *
+ * The primary purpose for this function is to allow the alternate mode drivers
+ * to tell which pin configuration has been negotiated with the partner. That
+ * information will then be used for example to configure the muxes.
+ * Communication to the other direction is also possible, and low level device
+ * drivers can also send notifications to the alternate mode drivers. The actual
+ * communication will be specific for every SVID.
+ */
+int typec_altmode_notify(struct typec_altmode *adev,
+			 unsigned long conf, void *data)
+{
+	bool is_port = is_typec_port(adev->dev.parent);
+	struct altmode *altmode;
+	struct altmode *partner;
+	int ret;
+
+	if (!adev)
+		return 0;
+
+	altmode = to_altmode(adev);
+
+	if (!altmode->partner)
+		return -ENODEV;
+
+	partner = altmode->partner;
+
+	ret = typec_altmode_set_mux(is_port ? altmode : partner, (u8)conf);
+	if (ret)
+		return ret;
+
+	blocking_notifier_call_chain(is_port ? &altmode->nh : &partner->nh,
+				     conf, data);
+
+	if (partner->adev.ops && partner->adev.ops->notify)
+		return partner->adev.ops->notify(&partner->adev, conf, data);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(typec_altmode_notify);
+
+/**
+ * typec_altmode_enter - Enter Mode
+ * @adev: The alternate mode
+ *
+ * The alternate mode drivers use this function to enter mode. The port drivers
+ * use this to inform the alternate mode drivers that the partner has initiated
+ * Enter Mode command.
+ */
+int typec_altmode_enter(struct typec_altmode *adev)
+{
+	struct altmode *partner = to_altmode(adev)->partner;
+	struct typec_altmode *pdev = &partner->adev;
+	int ret;
+
+	if (!adev || adev->active)
+		return 0;
+
+	if (!pdev->ops || !pdev->ops->enter)
+		return -EOPNOTSUPP;
+
+	/* Moving to USB Safe State */
+	ret = typec_altmode_set_state(adev, TYPEC_STATE_SAFE);
+	if (ret)
+		return ret;
+
+	/* Enter Mode */
+	return pdev->ops->enter(pdev);
+}
+EXPORT_SYMBOL_GPL(typec_altmode_enter);
+
+/**
+ * typec_altmode_exit - Exit Mode
+ * @adev: The alternate mode
+ *
+ * The partner of @adev has initiated Exit Mode command.
+ */
+int typec_altmode_exit(struct typec_altmode *adev)
+{
+	struct altmode *partner = to_altmode(adev)->partner;
+	struct typec_altmode *pdev = &partner->adev;
+	int ret;
+
+	if (!adev || !adev->active)
+		return 0;
+
+	if (!pdev->ops || !pdev->ops->enter)
+		return -EOPNOTSUPP;
+
+	/* Moving to USB Safe State */
+	ret = typec_altmode_set_state(adev, TYPEC_STATE_SAFE);
+	if (ret)
+		return ret;
+
+	/* Exit Mode command */
+	return pdev->ops->exit(pdev);
+}
+EXPORT_SYMBOL_GPL(typec_altmode_exit);
+
+/**
+ * typec_altmode_attention - Attention command
+ * @adev: The alternate mode
+ * @vdo: VDO for the Attention command
+ *
+ * Notifies the partner of @adev about Attention command.
+ */
+void typec_altmode_attention(struct typec_altmode *adev, u32 vdo)
+{
+	struct typec_altmode *pdev = &to_altmode(adev)->partner->adev;
+
+	if (pdev->ops && pdev->ops->attention)
+		pdev->ops->attention(pdev, vdo);
+}
+EXPORT_SYMBOL_GPL(typec_altmode_attention);
+
+/**
+ * typec_altmode_vdm - Send Vendor Defined Messages (VDM) to the partner
+ * @adev: Alternate mode handle
+ * @header: VDM Header
+ * @vdo: Array of Vendor Defined Data Objects
+ * @count: Number of Data Objects
+ *
+ * The alternate mode drivers use this function for SVID specific communication
+ * with the partner. The port drivers use it to deliver the Structured VDMs
+ * received from the partners to the alternate mode drivers.
+ */
+int typec_altmode_vdm(struct typec_altmode *adev,
+		      const u32 header, const u32 *vdo, int count)
+{
+	struct typec_altmode *pdev;
+	struct altmode *altmode;
+
+	if (!adev)
+		return 0;
+
+	altmode = to_altmode(adev);
+
+	if (!altmode->partner)
+		return -ENODEV;
+
+	pdev = &altmode->partner->adev;
+
+	if (!pdev->ops || !pdev->ops->vdm)
+		return -EOPNOTSUPP;
+
+	return pdev->ops->vdm(pdev, header, vdo, count);
+}
+EXPORT_SYMBOL_GPL(typec_altmode_vdm);
+
+const struct typec_altmode *
+typec_altmode_get_partner(struct typec_altmode *adev)
+{
+	return &to_altmode(adev)->partner->adev;
+}
+EXPORT_SYMBOL_GPL(typec_altmode_get_partner);
+
+/* -------------------------------------------------------------------------- */
+/* API for the alternate mode drivers */
+
+/**
+ * typec_altmode_get_plug - Find cable plug alternate mode
+ * @adev: Handle to partner alternate mode
+ * @index: Cable plug index
+ *
+ * Increment reference count for cable plug alternate mode device. Returns
+ * handle to the cable plug alternate mode, or NULL if none is found.
+ */
+struct typec_altmode *typec_altmode_get_plug(struct typec_altmode *adev,
+					     enum typec_plug_index index)
+{
+	struct altmode *port = to_altmode(adev)->partner;
+
+	if (port->plug[index]) {
+		get_device(&port->plug[index]->adev.dev);
+		return &port->plug[index]->adev;
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(typec_altmode_get_plug);
+
+/**
+ * typec_altmode_put_plug - Decrement cable plug alternate mode reference count
+ * @plug: Handle to the cable plug alternate mode
+ */
+void typec_altmode_put_plug(struct typec_altmode *plug)
+{
+	if (plug)
+		put_device(&plug->dev);
+}
+EXPORT_SYMBOL_GPL(typec_altmode_put_plug);
+
+int __typec_altmode_register_driver(struct typec_altmode_driver *drv,
+				    struct module *module)
+{
+	if (!drv->probe)
+		return -EINVAL;
+
+	drv->driver.owner = module;
+	drv->driver.bus = &typec_bus;
+
+	return driver_register(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(__typec_altmode_register_driver);
+
+void typec_altmode_unregister_driver(struct typec_altmode_driver *drv)
+{
+	driver_unregister(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(typec_altmode_unregister_driver);
+
+/* -------------------------------------------------------------------------- */
+/* API for the port drivers */
+
+/**
+ * typec_match_altmode - Match SVID to an array of alternate modes
+ * @altmodes: Array of alternate modes
+ * @n: Number of elements in the array, or -1 for NULL termiated arrays
+ * @svid: Standard or Vendor ID to match with
+ *
+ * Return pointer to an alternate mode with SVID mathing @svid, or NULL when no
+ * match is found.
+ */
+struct typec_altmode *typec_match_altmode(struct typec_altmode **altmodes,
+					  size_t n, u16 svid, u8 mode)
+{
+	int i;
+
+	for (i = 0; i < n; i++) {
+		if (!altmodes[i])
+			break;
+		if (altmodes[i]->svid == svid && altmodes[i]->mode == mode)
+			return altmodes[i];
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(typec_match_altmode);
+
+/* -------------------------------------------------------------------------- */
+
+static ssize_t
+description_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct typec_altmode *alt = to_typec_altmode(dev);
+
+	return sprintf(buf, "%s\n", alt->desc ? alt->desc : "");
+}
+static DEVICE_ATTR_RO(description);
+
+static struct attribute *typec_attrs[] = {
+	&dev_attr_description.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(typec);
+
+static int typec_match(struct device *dev, struct device_driver *driver)
+{
+	struct typec_altmode_driver *drv = to_altmode_driver(driver);
+	struct typec_altmode *altmode = to_typec_altmode(dev);
+	const struct typec_device_id *id;
+
+	for (id = drv->id_table; id->svid; id++)
+		if (id->svid == altmode->svid &&
+		    (id->mode == TYPEC_ANY_MODE || id->mode == altmode->mode))
+			return 1;
+	return 0;
+}
+
+static int typec_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	struct typec_altmode *altmode = to_typec_altmode(dev);
+
+	if (add_uevent_var(env, "SVID=%04X", altmode->svid))
+		return -ENOMEM;
+
+	if (add_uevent_var(env, "MODE=%u", altmode->mode))
+		return -ENOMEM;
+
+	return add_uevent_var(env, "MODALIAS=typec:id%04Xm%02X",
+			      altmode->svid, altmode->mode);
+}
+
+static int typec_altmode_create_links(struct altmode *alt)
+{
+	struct device *port_dev = &alt->partner->adev.dev;
+	struct device *dev = &alt->adev.dev;
+	int err;
+
+	err = sysfs_create_link(&dev->kobj, &port_dev->kobj, "port");
+	if (err)
+		return err;
+
+	err = sysfs_create_link(&port_dev->kobj, &dev->kobj, "partner");
+	if (err)
+		sysfs_remove_link(&dev->kobj, "port");
+
+	return err;
+}
+
+static void typec_altmode_remove_links(struct altmode *alt)
+{
+	sysfs_remove_link(&alt->partner->adev.dev.kobj, "partner");
+	sysfs_remove_link(&alt->adev.dev.kobj, "port");
+}
+
+static int typec_probe(struct device *dev)
+{
+	struct typec_altmode_driver *drv = to_altmode_driver(dev->driver);
+	struct typec_altmode *adev = to_typec_altmode(dev);
+	struct altmode *altmode = to_altmode(adev);
+	int ret;
+
+	/* Fail if the port does not support the alternate mode */
+	if (!altmode->partner)
+		return -ENODEV;
+
+	ret = typec_altmode_create_links(altmode);
+	if (ret) {
+		dev_warn(dev, "failed to create symlinks\n");
+		return ret;
+	}
+
+	ret = drv->probe(adev);
+	if (ret)
+		typec_altmode_remove_links(altmode);
+
+	return ret;
+}
+
+static int typec_remove(struct device *dev)
+{
+	struct typec_altmode_driver *drv = to_altmode_driver(dev->driver);
+	struct typec_altmode *adev = to_typec_altmode(dev);
+	struct altmode *altmode = to_altmode(adev);
+
+	typec_altmode_remove_links(altmode);
+
+	if (drv->remove)
+		drv->remove(to_typec_altmode(dev));
+
+	if (adev->active) {
+		WARN_ON(typec_altmode_set_state(adev, TYPEC_STATE_SAFE));
+		typec_altmode_update_active(adev, false);
+	}
+
+	adev->desc = NULL;
+	adev->ops = NULL;
+
+	return 0;
+}
+
+struct bus_type typec_bus = {
+	.name = "typec",
+	.dev_groups = typec_groups,
+	.match = typec_match,
+	.uevent = typec_uevent,
+	.probe = typec_probe,
+	.remove = typec_remove,
+};

drivers/usb/typec/bus.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __USB_TYPEC_ALTMODE_H__
+#define __USB_TYPEC_ALTMODE_H__
+
+#include <linux/usb/typec_altmode.h>
+#include <linux/usb/typec_mux.h>
+
+struct bus_type;
+
+struct altmode {
+	unsigned int			id;
+	struct typec_altmode		adev;
+	struct typec_mux		*mux;
+
+	enum typec_port_data		roles;
+
+	struct attribute		*attrs[5];
+	char				group_name[6];
+	struct attribute_group		group;
+	const struct attribute_group	*groups[2];
+
+	struct altmode			*partner;
+	struct altmode			*plug[2];
+
+	struct blocking_notifier_head	nh;
+};
+
+#define to_altmode(d) container_of(d, struct altmode, adev)
+
+extern struct bus_type typec_bus;
+extern const struct device_type typec_altmode_dev_type;
+extern const struct device_type typec_port_dev_type;
+
+#define is_typec_altmode(_dev_) (_dev_->type == &typec_altmode_dev_type)
+#define is_typec_port(_dev_) (_dev_->type == &typec_port_dev_type)
+
+#endif /* __USB_TYPEC_ALTMODE_H__ */

drivers/usb/typec/class.c

···
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
-#include <linux/usb/typec.h>
-#include <linux/usb/typec_mux.h>
 
-struct typec_altmode {
-	struct device			dev;
-	u16				svid;
-	u8				mode;
-
-	u32				vdo;
-	char				*desc;
-	enum typec_port_type		roles;
-	unsigned int			active:1;
-
-	struct attribute		*attrs[5];
-	char				group_name[6];
-	struct attribute_group		group;
-	const struct attribute_group	*groups[2];
-};
+#include "bus.h"
 
 struct typec_plug {
 	struct device			dev;
 	enum typec_plug_index		index;
+	struct ida			mode_ids;
 };
 
 struct typec_cable {
···
 	unsigned int			usb_pd:1;
 	struct usb_pd_identity		*identity;
 	enum typec_accessory		accessory;
+	struct ida			mode_ids;
 };
 
 struct typec_port {
 	unsigned int			id;
 	struct device			dev;
+	struct ida			mode_ids;
 
 	int				prefer_role;
 	enum typec_data_role		data_role;
···
 #define to_typec_plug(_dev_) container_of(_dev_, struct typec_plug, dev)
 #define to_typec_cable(_dev_) container_of(_dev_, struct typec_cable, dev)
 #define to_typec_partner(_dev_) container_of(_dev_, struct typec_partner, dev)
-#define to_altmode(_dev_) container_of(_dev_, struct typec_altmode, dev)
 
 static const struct device_type typec_partner_dev_type;
 static const struct device_type typec_cable_dev_type;
 static const struct device_type typec_plug_dev_type;
-static const struct device_type typec_port_dev_type;
 
 #define is_typec_partner(_dev_) (_dev_->type == &typec_partner_dev_type)
 #define is_typec_cable(_dev_) (_dev_->type == &typec_cable_dev_type)
 #define is_typec_plug(_dev_) (_dev_->type == &typec_plug_dev_type)
-#define is_typec_port(_dev_) (_dev_->type == &typec_port_dev_type)
 
 static DEFINE_IDA(typec_index_ida);
 static struct class *typec_class;
···
 /* ------------------------------------------------------------------------- */
 /* Alternate Modes */
 
+static int altmode_match(struct device *dev, void *data)
+{
+	struct typec_altmode *adev = to_typec_altmode(dev);
+	struct typec_device_id *id = data;
+
+	if (!is_typec_altmode(dev))
+		return 0;
+
+	return ((adev->svid == id->svid) && (adev->mode == id->mode));
+}
+
+static void typec_altmode_set_partner(struct altmode *altmode)
+{
+	struct typec_altmode *adev = &altmode->adev;
+	struct typec_device_id id = { adev->svid, adev->mode, };
+	struct typec_port *port = typec_altmode2port(adev);
+	struct altmode *partner;
+	struct device *dev;
+
+	dev = device_find_child(&port->dev, &id, altmode_match);
+	if (!dev)
+		return;
+
+	/* Bind the port alt mode to the partner/plug alt mode. */
+	partner = to_altmode(to_typec_altmode(dev));
+	altmode->partner = partner;
+
+	/* Bind the partner/plug alt mode to the port alt mode. */
+	if (is_typec_plug(adev->dev.parent)) {
+		struct typec_plug *plug = to_typec_plug(adev->dev.parent);
+
+		partner->plug[plug->index] = altmode;
+	} else {
+		partner->partner = altmode;
+	}
+}
+
+static void typec_altmode_put_partner(struct altmode *altmode)
+{
+	struct altmode *partner = altmode->partner;
+	struct typec_altmode *adev;
+
+	if (!partner)
+		return;
+
+	adev = &partner->adev;
+
+	if (is_typec_plug(adev->dev.parent)) {
+		struct typec_plug *plug = to_typec_plug(adev->dev.parent);
+
+		partner->plug[plug->index] = NULL;
+	} else {
+		partner->partner = NULL;
+	}
+	put_device(&adev->dev);
+}
+
+static int __typec_port_match(struct device *dev, const void *name)
+{
+	return !strcmp((const char *)name, dev_name(dev));
+}
+
+static void *typec_port_match(struct device_connection *con, int ep, void *data)
+{
+	return class_find_device(typec_class, NULL, con->endpoint[ep],
+				 __typec_port_match);
+}
+
+struct typec_altmode *
+typec_altmode_register_notifier(struct device *dev, u16 svid, u8 mode,
+				struct notifier_block *nb)
+{
+	struct typec_device_id id = { svid, mode, };
+	struct device *altmode_dev;
+	struct device *port_dev;
+	struct altmode *altmode;
+	int ret;
+
+	/* Find the port linked to the caller */
+	port_dev = device_connection_find_match(dev, NULL, NULL,
+						typec_port_match);
+	if (IS_ERR_OR_NULL(port_dev))
+		return port_dev ? ERR_CAST(port_dev) : ERR_PTR(-ENODEV);
+
+	/* Find the altmode with matching svid */
+	altmode_dev = device_find_child(port_dev, &id, altmode_match);
+
+	put_device(port_dev);
+
+	if (!altmode_dev)
+		return ERR_PTR(-ENODEV);
+
+	altmode = to_altmode(to_typec_altmode(altmode_dev));
+
+	/* Register notifier */
+	ret = blocking_notifier_chain_register(&altmode->nh, nb);
+	if (ret) {
+		put_device(altmode_dev);
+		return ERR_PTR(ret);
+	}
+
+	return &altmode->adev;
+}
+EXPORT_SYMBOL_GPL(typec_altmode_register_notifier);
+
+void typec_altmode_unregister_notifier(struct typec_altmode *adev,
+				       struct notifier_block *nb)
+{
+	struct altmode *altmode = to_altmode(adev);
+
+	blocking_notifier_chain_unregister(&altmode->nh, nb);
+	put_device(&adev->dev);
+}
+EXPORT_SYMBOL_GPL(typec_altmode_unregister_notifier);
+
 /**
  * typec_altmode_update_active - Report Enter/Exit mode
- * @alt: Handle to the alternate mode
+ * @adev: Handle to the alternate mode
  * @active: True when the mode has been entered
  *
  * If a partner or cable plug executes Enter/Exit Mode command successfully, the
  * drivers use this routine to report the updated state of the mode.
  */
-void typec_altmode_update_active(struct typec_altmode *alt, bool active)
+void typec_altmode_update_active(struct typec_altmode *adev, bool active)
 {
 	char dir[6];
 
-	if (alt->active == active)
+	if (adev->active == active)
 		return;
 
-	alt->active = active;
-	snprintf(dir, sizeof(dir), "mode%d", alt->mode);
-	sysfs_notify(&alt->dev.kobj, dir, "active");
-	kobject_uevent(&alt->dev.kobj, KOBJ_CHANGE);
+	if (!is_typec_port(adev->dev.parent)) {
+		if (!active)
+			module_put(adev->dev.driver->owner);
+		else
+			WARN_ON(!try_module_get(adev->dev.driver->owner));
+	}
+
+	adev->active = active;
+	snprintf(dir, sizeof(dir), "mode%d", adev->mode);
+	sysfs_notify(&adev->dev.kobj, dir, "active");
+	sysfs_notify(&adev->dev.kobj, NULL, "active");
+	kobject_uevent(&adev->dev.kobj, KOBJ_CHANGE);
 }
 EXPORT_SYMBOL_GPL(typec_altmode_update_active);
 
···
 static ssize_t
 vdo_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
-	struct typec_altmode *alt = to_altmode(dev);
+	struct typec_altmode *alt = to_typec_altmode(dev);
 
 	return sprintf(buf, "0x%08x\n", alt->vdo);
 }
···
 static ssize_t
 description_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
-	struct typec_altmode *alt = to_altmode(dev);
+	struct typec_altmode *alt = to_typec_altmode(dev);
 
 	return sprintf(buf, "%s\n", alt->desc ? alt->desc : "");
 }
···
 static ssize_t
 active_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
-	struct typec_altmode *alt = to_altmode(dev);
+	struct typec_altmode *alt = to_typec_altmode(dev);
 
 	return sprintf(buf, "%s\n", alt->active ? "yes" : "no");
 }
···
 static ssize_t active_store(struct device *dev, struct device_attribute *attr,
 			    const char *buf, size_t size)
 {
-	struct typec_altmode *alt = to_altmode(dev);
-	struct typec_port *port = typec_altmode2port(alt);
-	bool activate;
+	struct typec_altmode *adev = to_typec_altmode(dev);
+	struct altmode *altmode = to_altmode(adev);
+	bool enter;
 	int ret;
 
-	if (!port->cap->activate_mode)
-		return -EOPNOTSUPP;
-
-	ret = kstrtobool(buf, &activate);
+	ret = kstrtobool(buf, &enter);
 	if (ret)
 		return ret;
 
-	ret = port->cap->activate_mode(port->cap, alt->mode, activate);
-	if (ret)
-		return ret;
+	if (adev->active == enter)
+		return size;
+
+	if (is_typec_port(adev->dev.parent)) {
+		typec_altmode_update_active(adev, enter);
+
+		/* Make sure that the partner exits the mode before disabling */
+		if (altmode->partner && !enter && altmode->partner->adev.active)
+			typec_altmode_exit(&altmode->partner->adev);
+	} else if (altmode->partner) {
+		if (enter && !altmode->partner->adev.active) {
+			dev_warn(dev, "port has the mode disabled\n");
+			return -EPERM;
+		}
+	}
+
+	/* Note: If there is no driver, the mode will not be entered */
+	if (adev->ops && adev->ops->activate) {
+		ret = adev->ops->activate(adev, enter);
+		if (ret)
+			return ret;
+	}
 
 	return size;
 }
···
 supported_roles_show(struct device *dev, struct device_attribute *attr,
 		     char *buf)
 {
-	struct typec_altmode *alt = to_altmode(dev);
+	struct altmode *alt = to_altmode(to_typec_altmode(dev));
 	ssize_t ret;
 
 	switch (alt->roles) {
···
 }
 static DEVICE_ATTR_RO(supported_roles);
 
-static void typec_altmode_release(struct device *dev)
+static ssize_t
+mode_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
-	struct typec_altmode *alt = to_altmode(dev);
+	struct typec_altmode *adev = to_typec_altmode(dev);
 
-	kfree(alt);
+	return sprintf(buf, "%u\n", adev->mode);
 }
+static DEVICE_ATTR_RO(mode);
 
-static ssize_t svid_show(struct device *dev, struct device_attribute *attr,
-			 char *buf)
+static ssize_t
+svid_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
-	struct typec_altmode *alt = to_altmode(dev);
+	struct typec_altmode *adev = to_typec_altmode(dev);
 
-	return sprintf(buf, "%04x\n", alt->svid);
+	return sprintf(buf, "%04x\n", adev->svid);
 }
 static DEVICE_ATTR_RO(svid);
 
 static struct attribute *typec_altmode_attrs[] = {
+	&dev_attr_active.attr,
+	&dev_attr_mode.attr,
 	&dev_attr_svid.attr,
+	&dev_attr_vdo.attr,
 	NULL
 };
 ATTRIBUTE_GROUPS(typec_altmode);
 
-static const struct device_type typec_altmode_dev_type = {
+static int altmode_id_get(struct device *dev)
+{
+	struct ida *ids;
+
+	if (is_typec_partner(dev))
+		ids = &to_typec_partner(dev)->mode_ids;
+	else if (is_typec_plug(dev))
+		ids = &to_typec_plug(dev)->mode_ids;
+	else
+		ids = &to_typec_port(dev)->mode_ids;
+
+	return ida_simple_get(ids, 0, 0, GFP_KERNEL);
+}
+
+static void altmode_id_remove(struct device *dev, int id)
+{
+	struct ida *ids;
+
+	if (is_typec_partner(dev))
+		ids = &to_typec_partner(dev)->mode_ids;
+	else if (is_typec_plug(dev))
+		ids = &to_typec_plug(dev)->mode_ids;
+	else
+		ids = &to_typec_port(dev)->mode_ids;
+
+	ida_simple_remove(ids, id);
+}
+
+static void typec_altmode_release(struct device *dev)
+{
+	struct altmode *alt = to_altmode(to_typec_altmode(dev));
+
+	typec_altmode_put_partner(alt);
+
+	altmode_id_remove(alt->adev.dev.parent, alt->id);
+	kfree(alt);
+}
+
+const struct device_type typec_altmode_dev_type = {
 	.name = "typec_alternate_mode",
 	.groups = typec_altmode_groups,
 	.release = typec_altmode_release,
···
 typec_register_altmode(struct device *parent,
 		       const struct typec_altmode_desc *desc)
 {
-	struct typec_altmode *alt;
+	unsigned int id = altmode_id_get(parent);
+	bool is_port = is_typec_port(parent);
+	struct altmode *alt;
 	int ret;
 
 	alt = kzalloc(sizeof(*alt), GFP_KERNEL);
 	if (!alt)
 		return ERR_PTR(-ENOMEM);
 
-	alt->svid = desc->svid;
-	alt->mode = desc->mode;
-	alt->vdo = desc->vdo;
+	alt->adev.svid = desc->svid;
+	alt->adev.mode = desc->mode;
+	alt->adev.vdo = desc->vdo;
 	alt->roles = desc->roles;
+	alt->id = id;
 
 	alt->attrs[0] = &dev_attr_vdo.attr;
 	alt->attrs[1] = &dev_attr_description.attr;
 	alt->attrs[2] = &dev_attr_active.attr;
 
-	if (is_typec_port(parent))
+	if (is_port) {
 		alt->attrs[3] = &dev_attr_supported_roles.attr;
+		alt->adev.active = true; /* Enabled by default */
+	}
 
 	sprintf(alt->group_name, "mode%d", desc->mode);
 	alt->group.name = alt->group_name;
 	alt->group.attrs = alt->attrs;
 	alt->groups[0] = &alt->group;
 
-	alt->dev.parent = parent;
-	alt->dev.groups = alt->groups;
-	alt->dev.type = &typec_altmode_dev_type;
-	dev_set_name(&alt->dev, "%s-%04x:%u", dev_name(parent),
-		     alt->svid, alt->mode);
+	alt->adev.dev.parent = parent;
+	alt->adev.dev.groups = alt->groups;
+	alt->adev.dev.type = &typec_altmode_dev_type;
+	dev_set_name(&alt->adev.dev, "%s.%u", dev_name(parent), id);
 
-	ret = device_register(&alt->dev);
+	/* Link partners and plugs with the ports */
+	if (is_port)
+		BLOCKING_INIT_NOTIFIER_HEAD(&alt->nh);
+	else
+		typec_altmode_set_partner(alt);
+
+	/* The partners are bind to drivers */
+	if (is_typec_partner(parent))
+		alt->adev.dev.bus = &typec_bus;
+
+	ret = device_register(&alt->adev.dev);
 	if (ret) {
 		dev_err(parent, "failed to register alternate mode (%d)\n",
 			ret);
-		put_device(&alt->dev);
+		put_device(&alt->adev.dev);
 		return ERR_PTR(ret);
 	}
 
-	return alt;
+	return &alt->adev;
 }
 
 /**
  * typec_unregister_altmode - Unregister Alternate Mode
- * @alt: The alternate mode to be unregistered
+ * @adev: The alternate mode to be unregistered
  *
  * Unregister device created with typec_partner_register_altmode(),
  * typec_plug_register_altmode() or typec_port_register_altmode().
  */
-void typec_unregister_altmode(struct typec_altmode *alt)
+void typec_unregister_altmode(struct typec_altmode *adev)
 {
-	if (!IS_ERR_OR_NULL(alt))
-		device_unregister(&alt->dev);
+	if (IS_ERR_OR_NULL(adev))
+		return;
+	typec_mux_put(to_altmode(adev)->mux);
+	device_unregister(&adev->dev);
 }
 EXPORT_SYMBOL_GPL(typec_unregister_altmode);
 
···
 {
 	struct typec_partner *partner = to_typec_partner(dev);
 
+	ida_destroy(&partner->mode_ids);
 	kfree(partner);
 }
 
···
 	if (!partner)
 		return ERR_PTR(-ENOMEM);
 
+	ida_init(&partner->mode_ids);
 	partner->usb_pd = desc->usb_pd;
 	partner->accessory = desc->accessory;
 
···
 {
 	struct typec_plug *plug = to_typec_plug(dev);
 
+	ida_destroy(&plug->mode_ids);
 	kfree(plug);
 }
 
···
 
 	sprintf(name, "plug%d", desc->index);
 
+	ida_init(&plug->mode_ids);
 	plug->index = desc->index;
 	plug->dev.class = typec_class;
 	plug->dev.parent = &cable->dev;
···
 	struct typec_port *port = to_typec_port(dev);
 
 	ida_simple_remove(&typec_index_ida, port->id);
+	ida_destroy(&port->mode_ids);
 	typec_switch_put(port->sw);
 	typec_mux_put(port->mux);
 	kfree(port);
 }
 
-static const struct device_type typec_port_dev_type = {
+const struct device_type typec_port_dev_type = {
 	.name = "typec_port",
 	.groups = typec_groups,
 	.uevent = typec_uevent,
···
 
 /**
  * typec_set_mode - Set mode of operation for USB Type-C connector
- * @port: USB Type-C port for the connector
- * @mode: Operation mode for the connector
+ * @port: USB Type-C connector
+ * @mode: Accessory Mode, USB Operation or Safe State
  *
- * Set mode @mode for @port. This function will configure the muxes needed to
- * enter @mode.
+ * Configure @port for Accessory Mode @mode. This function will configure the
+ * muxes needed for @mode.
  */
 int typec_set_mode(struct typec_port *port, int mode)
 {
···
  * typec_port_register_altmode - Register USB Type-C Port Alternate Mode
  * @port: USB Type-C Port that supports the alternate mode
  * @desc: Description of the alternate mode
+ * @drvdata: Private pointer to driver specific info
  *
  * This routine is used to register an alternate mode that @port is capable of
  * supporting.
···
 typec_port_register_altmode(struct typec_port *port,
 			    const struct typec_altmode_desc *desc)
 {
-	return typec_register_altmode(&port->dev, desc);
+	struct typec_altmode *adev;
+	struct typec_mux *mux;
+	char id[10];
+
+	sprintf(id, "id%04xm%02x", desc->svid, desc->mode);
+
+	mux = typec_mux_get(port->dev.parent, id);
+	if (IS_ERR(mux))
+		return ERR_CAST(mux);
+
+	adev = typec_register_altmode(&port->dev, desc);
+	if (IS_ERR(adev))
+		typec_mux_put(mux);
+	else
+		to_altmode(adev)->mux = mux;
+
+	return adev;
 }
 EXPORT_SYMBOL_GPL(typec_port_register_altmode);
 
···
 		break;
 	}
 
+	ida_init(&port->mode_ids);
+	mutex_init(&port->port_type_lock);
+
 	port->id = id;
 	port->cap = cap;
 	port->port_type = cap->type;
-	mutex_init(&port->port_type_lock);
 	port->prefer_role = cap->prefer_role;
 
 	port->dev.class = typec_class;
···
 
 static int __init typec_init(void)
 {
+	int ret;
+
+	ret = bus_register(&typec_bus);
+	if (ret)
+		return ret;
+
 	typec_class = class_create(THIS_MODULE, "typec");
-	return PTR_ERR_OR_ZERO(typec_class);
+	if (IS_ERR(typec_class)) {
+		bus_unregister(&typec_bus);
+		return PTR_ERR(typec_class);
+	}
+
+	return 0;
 }
 subsys_initcall(typec_init);
 
···
 {
 	class_destroy(typec_class);
 	ida_destroy(&typec_index_ida);
+	bus_unregister(&typec_bus);
 }
 module_exit(typec_exit);
 

include/linux/mod_devicetable.h

···
 #define TBSVC_MATCH_PROTOCOL_VERSION	0x0004
 #define TBSVC_MATCH_PROTOCOL_REVISION	0x0008
 
+/* USB Type-C Alternate Modes */
+
+#define TYPEC_ANY_MODE	0x7
+
+/**
+ * struct typec_device_id - USB Type-C alternate mode identifiers
+ * @svid: Standard or Vendor ID
+ * @mode: Mode index
+ */
+struct typec_device_id {
+	__u16 svid;
+	__u8 mode;
+	kernel_ulong_t driver_data;
+};
+
 #endif /* LINUX_MOD_DEVICETABLE_H */

include/linux/usb/typec.h

···
 
 #include <linux/types.h>
 
-/* XXX: Once we have a header for USB Power Delivery, this belongs there */
-#define ALTMODE_MAX_MODES	6
-
 /* USB Type-C Specification releases */
 #define USB_TYPEC_REV_1_0	0x100 /* 1.0 */
 #define USB_TYPEC_REV_1_1	0x110 /* 1.1 */
 #define USB_TYPEC_REV_1_2	0x120 /* 1.2 */
 
-struct typec_altmode;
 struct typec_partner;
 struct typec_cable;
 struct typec_plug;
 struct typec_port;
 
 struct fwnode_handle;
+struct device;
 
 enum typec_port_type {
 	TYPEC_PORT_SRC,
···
 	u8			mode;
 	u32			vdo;
 	/* Only used with ports */
-	enum typec_port_type	roles;
+	enum typec_port_data	roles;
 };
 
 struct typec_altmode
···
  * @dr_set: Set Data Role
  * @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.
···
 				  enum typec_role);
 	int		(*vconn_set)(const struct typec_capability *,
 				     enum typec_role);
-
-	int		(*activate_mode)(const struct typec_capability *,
-					 int mode, int activate);
 	int		(*port_type_set)(const struct typec_capability *,
-					enum typec_port_type);
-
+					 enum typec_port_type);
 };
 
 /* Specific to try_role(). Indicates the user want's to clear the preference. */

include/linux/usb/typec_altmode.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __USB_TYPEC_ALTMODE_H
+#define __USB_TYPEC_ALTMODE_H
+
+#include <linux/mod_devicetable.h>
+#include <linux/usb/typec.h>
+#include <linux/device.h>
+
+#define MODE_DISCOVERY_MAX	6
+
+struct typec_altmode_ops;
+
+/**
+ * struct typec_altmode - USB Type-C alternate mode device
+ * @dev: Driver model's view of this device
+ * @svid: Standard or Vendor ID (SVID) of the alternate mode
+ * @mode: Index of the Mode
+ * @vdo: VDO returned by Discover Modes USB PD command
+ * @active: Tells has the mode been entered or not
+ * @desc: Optional human readable description of the mode
+ * @ops: Operations vector from the driver
+ */
+struct typec_altmode {
+	struct device			dev;
+	u16				svid;
+	int				mode;
+	u32				vdo;
+	unsigned int			active:1;
+
+	char				*desc;
+	const struct typec_altmode_ops	*ops;
+};
+
+#define to_typec_altmode(d) container_of(d, struct typec_altmode, dev)
+
+static inline void typec_altmode_set_drvdata(struct typec_altmode *altmode,
+					     void *data)
+{
+	dev_set_drvdata(&altmode->dev, data);
+}
+
+static inline void *typec_altmode_get_drvdata(struct typec_altmode *altmode)
+{
+	return dev_get_drvdata(&altmode->dev);
+}
+
+/**
+ * struct typec_altmode_ops - Alternate mode specific operations vector
+ * @enter: Operations to be executed with Enter Mode Command
+ * @exit: Operations to be executed with Exit Mode Command
+ * @attention: Callback for Attention Command
+ * @vdm: Callback for SVID specific commands
+ * @notify: Communication channel for platform and the alternate mode
+ * @activate: User callback for Enter/Exit Mode
+ */
+struct typec_altmode_ops {
+	int (*enter)(struct typec_altmode *altmode);
+	int (*exit)(struct typec_altmode *altmode);
+	void (*attention)(struct typec_altmode *altmode, u32 vdo);
+	int (*vdm)(struct typec_altmode *altmode, const u32 hdr,
+		   const u32 *vdo, int cnt);
+	int (*notify)(struct typec_altmode *altmode, unsigned long conf,
+		      void *data);
+	int (*activate)(struct typec_altmode *altmode, int activate);
+};
+
+int typec_altmode_enter(struct typec_altmode *altmode);
+int typec_altmode_exit(struct typec_altmode *altmode);
+void typec_altmode_attention(struct typec_altmode *altmode, u32 vdo);
+int typec_altmode_vdm(struct typec_altmode *altmode,
+		      const u32 header, const u32 *vdo, int count);
+int typec_altmode_notify(struct typec_altmode *altmode, unsigned long conf,
+			 void *data);
+const struct typec_altmode *
+typec_altmode_get_partner(struct typec_altmode *altmode);
+
+/*
+ * These are the connector states (USB, Safe and Alt Mode) defined in USB Type-C
+ * Specification. SVID specific connector states are expected to follow and
+ * start from the value TYPEC_STATE_MODAL.
+ */
+enum {
+	TYPEC_STATE_SAFE,	/* USB Safe State */
+	TYPEC_STATE_USB,	/* USB Operation */
+	TYPEC_STATE_MODAL,	/* Alternate Modes */
+};
+
+/*
+ * For the muxes there is no difference between Accessory Modes and Alternate
+ * Modes, so the Accessory Modes are supplied with specific modal state values
+ * here. Unlike with Alternate Modes, where the mux will be linked with the
+ * alternate mode device, the mux for Accessory Modes will be linked with the
+ * port device instead.
+ *
+ * Port drivers can use TYPEC_MODE_AUDIO and TYPEC_MODE_DEBUG as the mode
+ * value for typec_set_mode() when accessory modes are supported.
+ */
+enum {
+	TYPEC_MODE_AUDIO = TYPEC_STATE_MODAL,	/* Audio Accessory */
+	TYPEC_MODE_DEBUG,			/* Debug Accessory */
+};
+
+#define TYPEC_MODAL_STATE(_state_)	((_state_) + TYPEC_STATE_MODAL)
+
+struct typec_altmode *typec_altmode_get_plug(struct typec_altmode *altmode,
+					     enum typec_plug_index index);
+void typec_altmode_put_plug(struct typec_altmode *plug);
+
+struct typec_altmode *typec_match_altmode(struct typec_altmode **altmodes,
+					  size_t n, u16 svid, u8 mode);
+
+struct typec_altmode *
+typec_altmode_register_notifier(struct device *dev, u16 svid, u8 mode,
+				struct notifier_block *nb);
+
+void typec_altmode_unregister_notifier(struct typec_altmode *adev,
+				       struct notifier_block *nb);
+
+/**
+ * typec_altmode_get_orientation - Get cable plug orientation
+ * altmode: Handle to the alternate mode
+ */
+static inline enum typec_orientation
+typec_altmode_get_orientation(struct typec_altmode *altmode)
+{
+	return typec_get_orientation(typec_altmode2port(altmode));
+}
+
+/**
+ * struct typec_altmode_driver - USB Type-C alternate mode device driver
+ * @id_table: Null terminated array of SVIDs
+ * @probe: Callback for device binding
+ * @remove: Callback for device unbinding
+ * @driver: Device driver model driver
+ *
+ * These drivers will be bind to the partner alternate mode devices. They will
+ * handle all SVID specific communication.
+ */
+struct typec_altmode_driver {
+	const struct typec_device_id *id_table;
+	int (*probe)(struct typec_altmode *altmode);
+	void (*remove)(struct typec_altmode *altmode);
+	struct device_driver driver;
+};
+
+#define to_altmode_driver(d) container_of(d, struct typec_altmode_driver, \
+					  driver)
+
+#define typec_altmode_register_driver(drv) \
+		__typec_altmode_register_driver(drv, THIS_MODULE)
+int __typec_altmode_register_driver(struct typec_altmode_driver *drv,
+				    struct module *module);
+void typec_altmode_unregister_driver(struct typec_altmode_driver *drv);
+
+#define module_typec_altmode_driver(__typec_altmode_driver) \
+	module_driver(__typec_altmode_driver, typec_altmode_register_driver, \
+		      typec_altmode_unregister_driver)
+
+#endif /* __USB_TYPEC_ALTMODE_H */

scripts/mod/devicetable-offsets.c

···
 	DEVID_FIELD(tb_service_id, protocol_version);
 	DEVID_FIELD(tb_service_id, protocol_revision);
 
+	DEVID(typec_device_id);
+	DEVID_FIELD(typec_device_id, svid);
+	DEVID_FIELD(typec_device_id, mode);
+
 	return 0;
 }

scripts/mod/file2alias.c

···
 }
 ADD_TO_DEVTABLE("tbsvc", tb_service_id, do_tbsvc_entry);
 
+/* Looks like: typec:idNmN */
+static int do_typec_entry(const char *filename, void *symval, char *alias)
+{
+	DEF_FIELD(symval, typec_device_id, svid);
+	DEF_FIELD(symval, typec_device_id, mode);
+
+	sprintf(alias, "typec:id%04X", svid);
+	ADD(alias, "m", mode != TYPEC_ANY_MODE, mode);
+
+	return 1;
+}
+ADD_TO_DEVTABLE("typec", typec_device_id, do_typec_entry);
+
 /* Does namelen bytes of name exactly match the symbol? */
 static bool sym_is(const char *name, unsigned namelen, const char *symbol)
 {