USB: g_multi: Multifunction Composite Gadget added

The Multifunction Composite Gadget has two configurations
consisting of Ethernet (RNDIS in first and CDC Ethernet in
second configuration), CDC Serial and File-backed Storage
functions.

When connected to a Windows host, the first configuration
is chosen thus gadget provides RNDIS Ethernet, serial and
mass storage whereas when connected to Linux host, second
configuration is chosen thus providing CDC Ethernet,
serial and mass storage.

Which configurations are built can be configured via
KConfig options.

Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/Kconfig

@@ -812,6 +812,48 @@ config USB_CDC_COMPOSITE
 	  Say "y" to link the driver statically, or "m" to build a
 	  dynamically linked module.
 
+config USB_G_MULTI
+	tristate "Multifunction Composite Gadget (EXPERIMENTAL)"
+	help
+	  The Multifunction Composite Gadget provides Ethernet (RNDIS
+	  and/or CDC Ethernet), mass storage and ACM serial link
+	  interfaces.
+
+	  You will be asked too choose which of the two configurations are
+	  to be available in the gadget.  At least one configuration must
+	  be choosen to make gadget usable.  Selecting more then one
+	  configuration will prevent Windows from automatically detecting
+	  the gadget as a composite gadget an INF file will be needed to
+	  use the gadget.
+
+	  Say "y" to link the driver statically, or "m" to build a
+	  dynamically linked module called "g_multi".
+
+config USB_G_MULTI_RNDIS
+	bool "RNDIS + CDC Serial + Storage configuration"
+	depends on USB_G_MULTI
+	default y
+	help
+	  This option enables a configuration with RNDIS, CDC Serial and
+	  Mass Storage functions available in the Multifunction Composite
+	  Gadget.  This is configuration dedicated for Windows since RNDIS
+	  is Microsfot's protocol.
+
+	  If unsure, say "y".
+
+config USB_G_MULTI_CDC
+	bool "CDC Ethernet + CDC Serial + Storage configuration"
+	depends on USB_G_MULTI
+	default n
+	help
+	  This option enables a configuration with CDC Ethernet (ECM), CDC
+	  Serial and Mass Storage functions available in the Multifunction
+	  Composite Gadget.  This is configuration dedicated for Windows
+	  since RNDIS is Microsfot's protocol.
+
+	  If unsure, say "y".
+
+
 # put drivers that need isochronous transfer support (for audio
 # or video class gadget drivers), or specific hardware, here.
 

drivers/usb/gadget/Makefile

@@ -42,6 +42,7 @@ g_file_storage-objs		:= file_storage.o
 g_mass_storage-objs		:= mass_storage.o
 g_printer-objs			:= printer.o
 g_cdc-objs			:= cdc2.o
+g_multi-objs			:= multi.o
 
 obj-$(CONFIG_USB_ZERO)		+= g_zero.o
 obj-$(CONFIG_USB_AUDIO)		+= g_audio.o
@@ -53,4 +54,5 @@ obj-$(CONFIG_USB_G_SERIAL)	+= g_serial.o
 obj-$(CONFIG_USB_G_PRINTER)	+= g_printer.o
 obj-$(CONFIG_USB_MIDI_GADGET)	+= g_midi.o
 obj-$(CONFIG_USB_CDC_COMPOSITE) += g_cdc.o
+obj-$(CONFIG_USB_G_MULTI)	+= g_multi.o