usb: Bind devices to ACPI devices when possible

Built-in USB devices will typically have a representation in the system
ACPI tables. Add support for binding the two together so the USB code can
make use of the associated methods.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 0ce862b..7998a67 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -1015,6 +1015,9 @@
 	if (retval)
 		goto out;
 
+	retval = usb_acpi_register();
+	if (retval)
+		goto acpi_register_failed;
 	retval = bus_register(&usb_bus_type);
 	if (retval)
 		goto bus_register_failed;
@@ -1049,6 +1052,8 @@
 bus_notifier_failed:
 	bus_unregister(&usb_bus_type);
 bus_register_failed:
+	usb_acpi_unregister();
+acpi_register_failed:
 	usb_debugfs_cleanup();
 out:
 	return retval;
@@ -1070,6 +1075,7 @@
 	usb_hub_cleanup();
 	bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
 	bus_unregister(&usb_bus_type);
+	usb_acpi_unregister();
 	usb_debugfs_cleanup();
 }