usb: gadget: f_ncm: convert to new function interface with backward compatibility

Converting ncm to the new function interface requires converting
the USB ncm's function code and its users.

This patch converts the f_ncm.c to the new function interface.

The file is now compiled into a separate usb_f_ncm.ko module.

The old function interface is provided by means of a preprocessor
conditional directives. After all users are converted, the old interface
can be removed.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/Kconfig

@@ -511,6 +511,9 @@ config USB_F_SERIAL
 config USB_F_OBEX
 	tristate
 
+config USB_F_NCM
+	tristate
+
 choice
 	tristate "USB Gadget Drivers"
 	default USB_ETH

drivers/usb/gadget/Makefile

@@ -48,6 +48,8 @@ obj-$(CONFIG_USB_F_OBEX)	+= usb_f_obex.o
 obj-$(CONFIG_USB_U_ETHER)	+= u_ether.o
 u_rndis-y			:= rndis.o
 obj-$(CONFIG_USB_U_RNDIS)	+= u_rndis.o
+usb_f_ncm-y			:= f_ncm.o
+obj-$(CONFIG_USB_F_NCM)		+= usb_f_ncm.o
 
 #
 # USB gadget drivers

drivers/usb/gadget/ncm.c

@@ -36,6 +36,7 @@
  * the runtime footprint, and giving us at least some parts of what
  * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
  */
+#define USB_FNCM_INCLUDED
 #include "f_ncm.c"
 
 /*-------------------------------------------------------------------------*/

drivers/usb/gadget/u_ncm.h

+/*
+ * u_ncm.h
+ *
+ * Utility definitions for the ncm function
+ *
+ * Copyright (c) 2013 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * Author: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef U_NCM_H
+#define U_NCM_H
+
+#include <linux/usb/composite.h>
+
+struct f_ncm_opts {
+	struct usb_function_instance	func_inst;
+	struct net_device		*net;
+	bool				bound;
+};
+
+#endif /* U_NCM_H */