Input: wacom - use only one interface with DTU-2231

The Wacom DTU-2231 tablet has two interfaces on its default configuration
and both have HID class, leading to the creation of two input devices
instead of one. Only the first one is used, so filter out the second.
Signed-off-by: Aristeu Rozanski <aris@redhat.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/tablet/wacom_wac.c

@@ -15,6 +15,7 @@
 #include "wacom_wac.h"
 #include "wacom.h"
 #include <linux/input/mt.h>
+#include <linux/hid.h>
 
 /* resolution for penabled devices */
 #define WACOM_PL_RES		20
@@ -1486,6 +1487,11 @@ static const struct wacom_features wacom_features_0x6004 =
 	USB_DEVICE(USB_VENDOR_ID_WACOM, prod),			\
 	.driver_info = (kernel_ulong_t)&wacom_features_##prod
 
+#define USB_DEVICE_DETAILED(prod, class, sub, proto)			\
+	USB_DEVICE_AND_INTERFACE_INFO(USB_VENDOR_ID_WACOM, prod, class,	\
+				      sub, proto),			\
+	.driver_info = (kernel_ulong_t)&wacom_features_##prod
+
 #define USB_DEVICE_LENOVO(prod)					\
 	USB_DEVICE(USB_VENDOR_ID_LENOVO, prod),			\
 	.driver_info = (kernel_ulong_t)&wacom_features_##prod
@@ -1548,7 +1554,13 @@ const struct usb_device_id wacom_ids[] = {
 	{ USB_DEVICE_WACOM(0xC5) },
 	{ USB_DEVICE_WACOM(0xC6) },
 	{ USB_DEVICE_WACOM(0xC7) },
-	{ USB_DEVICE_WACOM(0xCE) },
+	/*
+	 * DTU-2231 has two interfaces on the same configuration,
+	 * only one is used.
+	 */
+	{ USB_DEVICE_DETAILED(0xCE, USB_CLASS_HID,
+			      USB_INTERFACE_SUBCLASS_BOOT,
+			      USB_INTERFACE_PROTOCOL_MOUSE) },
 	{ USB_DEVICE_WACOM(0xD0) },
 	{ USB_DEVICE_WACOM(0xD1) },
 	{ USB_DEVICE_WACOM(0xD2) },