USB: allow match on bInterfaceNumber

Some composite USB devices provide multiple interfaces
with different functions, all using "vendor-specific"
for class/subclass/protocol.  Another OS use interface
numbers to match the driver and interface. It seems
these devices are designed with that in mind - using
static interface numbers for the different functions.

This adds support for matching against the
bInterfaceNumber, allowing such devices to be supported
without having to resort to testing against interface
number whitelists and/or blacklists in the probe.

Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index 5db9382..7771d45 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -78,6 +78,9 @@
  *	of a given interface; other interfaces may support other classes.
  * @bInterfaceSubClass: Subclass of interface; associated with bInterfaceClass.
  * @bInterfaceProtocol: Protocol of interface; associated with bInterfaceClass.
+ * @bInterfaceNumber: Number of interface; composite devices may use
+ *	fixed interface numbers to differentiate between vendor-specific
+ *	interfaces.
  * @driver_info: Holds information used by the driver.  Usually it holds
  *	a pointer to a descriptor understood by the driver, or perhaps
  *	device flags.
@@ -115,6 +118,9 @@
 	__u8		bInterfaceSubClass;
 	__u8		bInterfaceProtocol;
 
+	/* Used for vendor-specific interface matches */
+	__u8		bInterfaceNumber;
+
 	/* not matched against */
 	kernel_ulong_t	driver_info;
 };
@@ -130,6 +136,7 @@
 #define USB_DEVICE_ID_MATCH_INT_CLASS		0x0080
 #define USB_DEVICE_ID_MATCH_INT_SUBCLASS	0x0100
 #define USB_DEVICE_ID_MATCH_INT_PROTOCOL	0x0200
+#define USB_DEVICE_ID_MATCH_INT_NUMBER		0x0400
 
 #define HID_ANY_ID				(~0)
 #define HID_BUS_ANY				0xffff