[PATCHv2] usb: typec: Add type sysfs attribute file for partners

diff --git a/Documentation/ABI/testing/sysfs-class-typec b/Documentation/ABI/testing/sysfs-class-typec
index 619c4c67432b9..8eab41e79ce68 100644
--- a/Documentation/ABI/testing/sysfs-class-typec
+++ b/Documentation/ABI/testing/sysfs-class-typec
@@ -147,6 +147,52 @@  Description:
 		during Power Delivery discovery. This file remains hidden until a value
 		greater than or equal to 0 is set by Type C port driver.
 
+What:		/sys/class/typec/<port>-partner/type
+Date:		December 2020
+Contact:	Heikki Krogerus <heikki.krogerus@linux.intel.com>
+Description:	USB Power Delivery Specification defines a set of product types
+		for the partner devices. This file will show the product type of
+		the partner if it is known. Dual-role capable partners will have
+		both UFP and DFP product types defined, but only one that
+		matches the current role will be active at the time. If the
+		product type of the partner is not visible to the device driver,
+		this file will not exist.
+
+		When the partner product type is detected, or changed with role
+		swap, uvevent is also raised that contains PRODUCT_TYPE=<product
+		type> (for example PRODUCT_TYPE=hub).
+
+		Valid values:
+
+		UFP / device role
+		======================  ==========================
+		undefined		-
+		hub			PDUSB Hub
+		peripheral		PDUSB Peripheral
+		psd			Power Bank
+		ama			Alternate Mode Adapter
+		======================  ==========================
+
+		DFP / host role
+		======================  ==========================
+		undefined		-
+		hub			PDUSB Hub
+		host			PDUSB Host
+		power_brick		Power Brick
+		amc			Alternate Mode Controller
+		======================  ==========================
+
+What:		/sys/class/typec/<port>-partner>/identity/
+Date:		April 2017
+Contact:	Heikki Krogerus <heikki.krogerus@linux.intel.com>
+Description:
+		This directory appears only if the port device driver is capable
+		of showing the result of Discover Identity USB power delivery
+		command. That will not always be possible even when USB power
+		delivery is supported, for example when USB power delivery
+		communication for the port is mostly handled in firmware. If the
+		directory exists, it will have an attribute file for every VDO
+		in Discover Identity command result.
 
 USB Type-C cable devices (eg. /sys/class/typec/port0-cable/)
 
@@ -159,9 +205,21 @@  described in USB Type-C and USB Power Delivery specifications.
 What:		/sys/class/typec/<port>-cable/type
 Date:		April 2017
 Contact:	Heikki Krogerus <heikki.krogerus@linux.intel.com>
-Description:
-		Shows if the cable is active.
-		Valid values: active, passive
+Description:	USB Power Delivery Specification defines a set of product types
+		for the cables. This file will show the product type of the
+		cable if it is known. If the product type of the cable is not
+		visible to the device driver, this file will not exist.
+
+		When the cable product type is detected, uvevent is also raised
+		with PRODUCT_TYPE showing the product type of the cable.
+
+		Valid values:
+
+		======================  ==========================
+		undefined		-
+		active			Active Cable
+		passive			Passive Cable
+		======================  ==========================
 
 What:		/sys/class/typec/<port>-cable/plug_type
 Date:		April 2017
diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
index 8f40093c20449..4f6e58dfb81d5 100644
--- a/drivers/usb/typec/class.c
+++ b/drivers/usb/typec/class.c
@@ -11,6 +11,7 @@ 
 #include <linux/mutex.h>
 #include <linux/property.h>
 #include <linux/slab.h>
+#include <linux/usb/pd_vdo.h>
 
 #include "bus.h"
 
@@ -83,6 +84,29 @@  static const char * const typec_accessory_modes[] = {
 	[TYPEC_ACCESSORY_DEBUG]		= "debug",
 };
 
+/* Product types defined in USB PD Specification R3.0 V2.0 */
+static const char * const product_type_ufp[8] = {
+	[IDH_PTYPE_UNDEF]		= "undefined",
+	[IDH_PTYPE_HUB]			= "hub",
+	[IDH_PTYPE_PERIPH]		= "peripheral",
+	[IDH_PTYPE_PSD]			= "psd",
+	[IDH_PTYPE_AMA]			= "ama",
+};
+
+static const char * const product_type_dfp[8] = {
+	[IDH_PTYPE_DFP_UNDEF]		= "undefined",
+	[IDH_PTYPE_DFP_HUB]		= "hub",
+	[IDH_PTYPE_DFP_HOST]		= "host",
+	[IDH_PTYPE_DFP_PB]		= "power_brick",
+	[IDH_PTYPE_DFP_AMC]		= "amc",
+};
+
+static const char * const product_type_cable[8] = {
+	[IDH_PTYPE_UNDEF]		= "undefined",
+	[IDH_PTYPE_PCABLE]		= "passive",
+	[IDH_PTYPE_ACABLE]		= "active",
+};
+
 static struct usb_pd_identity *get_pd_identity(struct device *dev)
 {
 	if (is_typec_partner(dev)) {
@@ -97,6 +121,32 @@  static struct usb_pd_identity *get_pd_identity(struct device *dev)
 	return NULL;
 }
 
+static const char *get_pd_product_type(struct device *dev)
+{
+	struct typec_port *port = to_typec_port(dev->parent);
+	struct usb_pd_identity *id = get_pd_identity(dev);
+	const char *ptype = NULL;
+
+	if (is_typec_partner(dev)) {
+		if (!id)
+			return NULL;
+
+		if (port->data_role == TYPEC_HOST)
+			ptype = product_type_ufp[PD_IDH_PTYPE(id->id_header)];
+		else
+			ptype = product_type_dfp[PD_IDH_DFP_PTYPE(id->id_header)];
+	} else if (is_typec_cable(dev)) {
+		if (id)
+			ptype = product_type_cable[PD_IDH_PTYPE(id->id_header)];
+		else
+			ptype = to_typec_cable(dev)->active ?
+				product_type_cable[IDH_PTYPE_ACABLE] :
+				product_type_cable[IDH_PTYPE_PCABLE];
+	}
+
+	return ptype;
+}
+
 static ssize_t id_header_show(struct device *dev, struct device_attribute *attr,
 			      char *buf)
 {
@@ -171,6 +221,25 @@  static const struct attribute_group *usb_pd_id_groups[] = {
 	NULL,
 };
 
+static void typec_product_type_notify(struct device *dev)
+{
+	char *envp[2] = { };
+	const char *ptype;
+
+	ptype = get_pd_product_type(dev);
+	if (!ptype)
+		return;
+
+	sysfs_notify(&dev->kobj, NULL, "type");
+
+	envp[0] = kasprintf(GFP_KERNEL, "PRODUCT_TYPE=%s", ptype);
+	if (!envp[0])
+		return;
+
+	kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
+	kfree(envp[0]);
+}
+
 static void typec_report_identity(struct device *dev)
 {
 	sysfs_notify(&dev->kobj, "identity", "id_header");
@@ -179,7 +248,21 @@  static void typec_report_identity(struct device *dev)
 	sysfs_notify(&dev->kobj, "identity", "product_type_vdo1");
 	sysfs_notify(&dev->kobj, "identity", "product_type_vdo2");
 	sysfs_notify(&dev->kobj, "identity", "product_type_vdo3");
+	typec_product_type_notify(dev);
+}
+
+static ssize_t
+type_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	const char *ptype;
+
+	ptype = get_pd_product_type(dev);
+	if (!ptype)
+		return 0;
+
+	return sysfs_emit(buf, "%s\n", ptype);
 }
+static DEVICE_ATTR_RO(type);
 
 /* ------------------------------------------------------------------------- */
 /* Alternate Modes */
@@ -592,6 +675,7 @@  static struct attribute *typec_partner_attrs[] = {
 	&dev_attr_accessory_mode.attr,
 	&dev_attr_supports_usb_power_delivery.attr,
 	&dev_attr_number_of_alternate_modes.attr,
+	&dev_attr_type.attr,
 	NULL
 };
 
@@ -604,6 +688,10 @@  static umode_t typec_partner_attr_is_visible(struct kobject *kobj, struct attrib
 			return 0;
 	}
 
+	if (attr == &dev_attr_type.attr)
+		if (!get_pd_product_type(kobj_to_dev(kobj)))
+			return 0;
+
 	return attr->mode;
 }
 
@@ -914,15 +1002,6 @@  EXPORT_SYMBOL_GPL(typec_unregister_plug);
 
 /* Type-C Cables */
 
-static ssize_t
-type_show(struct device *dev, struct device_attribute *attr, char *buf)
-{
-	struct typec_cable *cable = to_typec_cable(dev);
-
-	return sprintf(buf, "%s\n", cable->active ? "active" : "passive");
-}
-static DEVICE_ATTR_RO(type);
-
 static const char * const typec_plug_types[] = {
 	[USB_PLUG_NONE]		= "unknown",
 	[USB_PLUG_TYPE_A]	= "type-a",
@@ -1522,6 +1601,11 @@  const struct device_type typec_port_dev_type = {
 /* --------------------------------------- */
 /* Driver callbacks to report role updates */
 
+static int partner_match(struct device *dev, void *data)
+{
+	return is_typec_partner(dev);
+}
+
 /**
  * typec_set_data_role - Report data role change
  * @port: The USB Type-C Port where the role was changed
@@ -1531,12 +1615,23 @@  const struct device_type typec_port_dev_type = {
  */
 void typec_set_data_role(struct typec_port *port, enum typec_data_role role)
 {
+	struct device *partner_dev;
+
 	if (port->data_role == role)
 		return;
 
 	port->data_role = role;
 	sysfs_notify(&port->dev.kobj, NULL, "data_role");
 	kobject_uevent(&port->dev.kobj, KOBJ_CHANGE);
+
+	partner_dev = device_find_child(&port->dev, NULL, partner_match);
+	if (!partner_dev)
+		return;
+
+	if (to_typec_partner(partner_dev)->identity)
+		typec_product_type_notify(partner_dev);
+
+	put_device(partner_dev);
 }
 EXPORT_SYMBOL_GPL(typec_set_data_role);
 
@@ -1577,11 +1672,6 @@  void typec_set_vconn_role(struct typec_port *port, enum typec_role role)
 }
 EXPORT_SYMBOL_GPL(typec_set_vconn_role);
 
-static int partner_match(struct device *dev, void *data)
-{
-	return is_typec_partner(dev);
-}
-
 /**
  * typec_set_pwr_opmode - Report changed power operation mode
  * @port: The USB Type-C Port where the mode was changed