USB: add gadget serial driver from Al Borchers

drivers/usb/gadget/Kconfig

@@ -177,6 +177,27 @@ config USB_GADGETFS_PXA2XX
 	depends on USB_GADGETFS && USB_PXA2XX
 	default y
 
+config USB_G_SERIAL
+	tristate "serial Gadget"
+	depends on USB_GADGET && (USB_DUMMY_HCD || USB_NET2280 || USB_PXA2XX || USB_SA1100)
+
+config USB_G_SERIAL_NET2280
+	bool
+	# for now, treat the "dummy" hcd as if it were a net2280
+	depends on USB_G_SERIAL && (USB_NET2280 || USB_DUMMY_HCD)
+	default y
+
+config USB_G_SERIAL_PXA2XX
+	bool
+	depends on USB_G_SERIAL && USB_PXA2XX
+	default y
+
+config USB_G_SERIAL_SA1100
+	bool
+	depends on USB_G_SERIAL && USB_SA1100
+	default y
+
+
 endchoice
 
 # endmenuconfig

drivers/usb/gadget/Makefile

@@ -8,9 +8,10 @@ obj-$(CONFIG_USB_NET2280)	+= net2280.o
 #
 g_zero-objs			:= zero.o usbstring.o
 g_ether-objs			:= ether.o usbstring.o
+g_serial-objs			:= serial.o usbstring.o
 gadgetfs-objs			:= inode.o usbstring.o
  
 obj-$(CONFIG_USB_ZERO)		+= g_zero.o
 obj-$(CONFIG_USB_ETH)		+= g_ether.o
 obj-$(CONFIG_USB_GADGETFS)	+= gadgetfs.o
-
+obj-$(CONFIG_USB_G_SERIAL)	+= g_serial.o