usb gadget: cdc obex glue

The following patch introduces a new f_obex.c function driver.
It allows userspace obex servers to use usb as transport layer
for their messages.

[ dbrownell@users.sourceforge.net: various fixes and cleanups ]
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Documentation/DocBook/gadget.tmpl

@@ -557,6 +557,9 @@ Near-term plans include converting all of them, except for "gadgetfs".
 </para>
 
 !Edrivers/usb/gadget/f_acm.c
+!Edrivers/usb/gadget/f_ecm.c
+!Edrivers/usb/gadget/f_subset.c
+!Edrivers/usb/gadget/f_obex.c
 !Edrivers/usb/gadget/f_serial.c
 
 </sect1>

drivers/usb/gadget/Kconfig

@@ -576,19 +576,23 @@ config USB_FILE_STORAGE_TEST
 	  normal operation.
 
 config USB_G_SERIAL
-	tristate "Serial Gadget (with CDC ACM support)"
+	tristate "Serial Gadget (with CDC ACM and CDC OBEX support)"
 	help
 	  The Serial Gadget talks to the Linux-USB generic serial driver.
 	  This driver supports a CDC-ACM module option, which can be used
 	  to interoperate with MS-Windows hosts or with the Linux-USB
 	  "cdc-acm" driver.
 
+	  This driver also supports a CDC-OBEX option.  You will need a
+	  user space OBEX server talking to /dev/ttyGS*, since the kernel
+	  itself doesn't implement the OBEX protocol.
+
 	  Say "y" to link the driver statically, or "m" to build a
 	  dynamically linked module called "g_serial".
 
 	  For more information, see Documentation/usb/gadget_serial.txt
 	  which includes instructions and a "driver info file" needed to
-	  make MS-Windows work with this driver.
+	  make MS-Windows work with CDC ACM.
 
 config USB_MIDI_GADGET
 	tristate "MIDI Gadget (EXPERIMENTAL)"

drivers/usb/gadget/serial.c

@@ -43,6 +43,7 @@
 #include "epautoconf.c"
 
 #include "f_acm.c"
+#include "f_obex.c"
 #include "f_serial.c"
 #include "u_serial.c"
 
@@ -56,6 +57,7 @@
 #define GS_VENDOR_ID			0x0525	/* NetChip */
 #define GS_PRODUCT_ID			0xa4a6	/* Linux-USB Serial Gadget */
 #define GS_CDC_PRODUCT_ID		0xa4a7	/* ... as CDC-ACM */
+#define GS_CDC_OBEX_PRODUCT_ID		0xa4a9	/* ... as CDC-OBEX */
 
 /* string IDs are assigned dynamically */
 
@@ -125,6 +127,10 @@ static int use_acm = true;
 module_param(use_acm, bool, 0);
 MODULE_PARM_DESC(use_acm, "Use CDC ACM, default=yes");
 
+static int use_obex = false;
+module_param(use_obex, bool, 0);
+MODULE_PARM_DESC(use_obex, "Use CDC OBEX, default=no");
+
 static unsigned n_ports = 1;
 module_param(n_ports, uint, 0);
 MODULE_PARM_DESC(n_ports, "number of ports to create, default=1");
@@ -139,6 +145,8 @@ static int __init serial_bind_config(struct usb_configuration *c)
 	for (i = 0; i < n_ports && status == 0; i++) {
 		if (use_acm)
 			status = acm_bind_config(c, i);
+		else if (use_obex)
+			status = obex_bind_config(c, i);
 		else
 			status = gser_bind_config(c, i);
 	}
@@ -249,6 +257,12 @@ static int __init init(void)
 		device_desc.bDeviceClass = USB_CLASS_COMM;
 		device_desc.idProduct =
 				__constant_cpu_to_le16(GS_CDC_PRODUCT_ID);
+	} else if (use_obex) {
+		serial_config_driver.label = "CDC OBEX config";
+		serial_config_driver.bConfigurationValue = 3;
+		device_desc.bDeviceClass = USB_CLASS_COMM;
+		device_desc.idProduct =
+			__constant_cpu_to_le16(GS_CDC_OBEX_PRODUCT_ID);
 	} else {
 		serial_config_driver.label = "Generic Serial config";
 		serial_config_driver.bConfigurationValue = 1;

drivers/usb/gadget/u_serial.h

@@ -62,5 +62,6 @@ void gserial_disconnect(struct gserial *);
 /* functions are bound to configurations by a config or gadget driver */
 int acm_bind_config(struct usb_configuration *c, u8 port_num);
 int gser_bind_config(struct usb_configuration *c, u8 port_num);
+int obex_bind_config(struct usb_configuration *c, u8 port_num);
 
 #endif /* __U_SERIAL_H */

include/linux/usb/cdc.h

@@ -160,6 +160,15 @@ struct usb_cdc_mdlm_detail_desc {
 	__u8	bDetailData[0];
 } __attribute__ ((packed));
 
+/* "OBEX Control Model Functional Descriptor" */
+struct usb_cdc_obex_desc {
+	__u8	bLength;
+	__u8	bDescriptorType;
+	__u8	bDescriptorSubType;
+
+	__le16	bcdVersion;
+} __attribute__ ((packed));
+
 /*-------------------------------------------------------------------------*/
 
 /*