greybus: usb: Create separate module

Create separate module for usb gpbridge driver.

Tested on EVT 1.5 by inserting GP test module, all the devices were
enumerated correctly.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
diff --git a/drivers/staging/greybus/Makefile b/drivers/staging/greybus/Makefile
index e99a9a8..592525c 100644
--- a/drivers/staging/greybus/Makefile
+++ b/drivers/staging/greybus/Makefile
@@ -14,8 +14,7 @@
 		operation.o	\
 		legacy.o
 
-gb-phy-y :=	gpbridge.o	\
-		usb.o
+gb-phy-y :=	gpbridge.o
 
 # Prefix all modules with gb-
 gb-vibrator-y := vibrator.o
@@ -40,6 +39,7 @@
 gb-pwm-y := pwm.o
 gb-gpio-y := gpio.o
 gb-i2c-y := i2c.o
+gb-usb-y := usb.o
 
 obj-m += greybus.o
 obj-m += gb-phy.o
@@ -68,6 +68,7 @@
 obj-m += gb-pwm.o
 obj-m += gb-gpio.o
 obj-m += gb-i2c.o
+obj-m += gb-usb.o
 
 KERNELVER		?= $(shell uname -r)
 KERNELDIR 		?= /lib/modules/$(KERNELVER)/build
diff --git a/drivers/staging/greybus/gpbridge.c b/drivers/staging/greybus/gpbridge.c
index 5a65564..67f18ac 100644
--- a/drivers/staging/greybus/gpbridge.c
+++ b/drivers/staging/greybus/gpbridge.c
@@ -317,15 +317,8 @@
 		goto error_gpbridge;
 	}
 
-	if (gb_usb_driver_init()) {
-		pr_err("error initializing usb driver\n");
-		goto error_usb;
-	}
-
 	return 0;
 
-error_usb:
-	greybus_deregister(&gb_gpbridge_driver);
 error_gpbridge:
 	bus_unregister(&gpbridge_bus_type);
 	ida_destroy(&gpbridge_id);
@@ -335,8 +328,6 @@
 
 static void __exit gpbridge_exit(void)
 {
-	gb_usb_driver_exit();
-
 	greybus_deregister(&gb_gpbridge_driver);
 	bus_unregister(&gpbridge_bus_type);
 	ida_destroy(&gpbridge_id);
diff --git a/drivers/staging/greybus/gpbridge.h b/drivers/staging/greybus/gpbridge.h
index 532dd56..d4339e6 100644
--- a/drivers/staging/greybus/gpbridge.h
+++ b/drivers/staging/greybus/gpbridge.h
@@ -66,9 +66,6 @@
 	gb_gpbridge_deregister(&__driver);			\
 }
 
-extern int gb_usb_driver_init(void);
-extern void gb_usb_driver_exit(void);
-
 /**
  * module_gpbridge_driver() - Helper macro for registering a gpbridge driver
  * @__gpbridge_driver: gpbridge_driver structure
diff --git a/drivers/staging/greybus/usb.c b/drivers/staging/greybus/usb.c
index 2b4789b..2f68a1b 100644
--- a/drivers/staging/greybus/usb.c
+++ b/drivers/staging/greybus/usb.c
@@ -242,6 +242,7 @@
 	{ GPBRIDGE_PROTOCOL(GREYBUS_PROTOCOL_USB) },
 	{ },
 };
+MODULE_DEVICE_TABLE(gpbridge, gb_usb_id_table);
 
 static struct gpbridge_driver usb_driver = {
 	.name		= "usb",
@@ -249,4 +250,6 @@
 	.remove		= gb_usb_remove,
 	.id_table	= gb_usb_id_table,
 };
-gb_gpbridge_builtin_driver(usb_driver);
+
+module_gpbridge_driver(usb_driver);
+MODULE_LICENSE("GPL v2");