usb: roles: Allow the role switches to be named

The switch devices have been named by using the name of the
parent device as base for now, but if for example the
parent device controls multiple muxes, that will not work.

Adding an optional member "name" to the switch descriptor
that can be used for naming the switch during registration.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20200302135353.56659-7-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/roles/class.c

@@ -330,7 +330,8 @@ usb_role_switch_register(struct device *parent,
 	sw->dev.class = role_class;
 	sw->dev.type = &usb_role_dev_type;
 	dev_set_drvdata(&sw->dev, desc->driver_data);
-	dev_set_name(&sw->dev, "%s-role-switch", dev_name(parent));
+	dev_set_name(&sw->dev, "%s-role-switch",
+		     desc->name ? desc->name : dev_name(parent));
 
 	ret = device_register(&sw->dev);
 	if (ret) {

include/linux/usb/role.h

@@ -27,6 +27,7 @@ typedef enum usb_role (*usb_role_switch_get_t)(struct usb_role_switch *sw);
  * @get: Callback for getting the role (optional)
  * @allow_userspace_control: If true userspace may change the role through sysfs
  * @driver_data: Private data pointer
+ * @name: Name for the switch (optional)
  *
  * @usb2_port and @usb3_port will point to the USB host port and @udc to the USB
  * device controller behind the USB connector with the role switch. If
@@ -43,6 +44,7 @@ struct usb_role_switch_desc {
 	usb_role_switch_get_t get;
 	bool allow_userspace_control;
 	void *driver_data;
+	const char *name;
 };