HID: detect Win 8 multitouch devices in core

Detecting Win 8 multitouch devices in core allows us to set quirks
before the device is parsed through hid_hw_start().
It also simplifies the detection of those devices in hid-multitouch and
makes the handling of those devices cleaner.

As Win 8 multitouch panels are in the group multitouch and rely on a
special feature to be detected, this patch adds a bitfield in the parser.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Henrik Rydberg <rydberg@euromail.se>
Tested-by: Srinivas Pandruvada<srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/include/linux/hid.h b/include/linux/hid.h
index 0c48991..cef1e9b 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -295,6 +295,7 @@
 #define HID_GROUP_GENERIC			0x0001
 #define HID_GROUP_MULTITOUCH			0x0002
 #define HID_GROUP_SENSOR_HUB			0x0003
+#define HID_GROUP_MULTITOUCH_WIN_8		0x0004
 
 /*
  * This is the global environment of the parser. This information is
@@ -532,6 +533,8 @@
 #define HID_GLOBAL_STACK_SIZE 4
 #define HID_COLLECTION_STACK_SIZE 4
 
+#define HID_SCAN_FLAG_MT_WIN_8			0x00000001
+
 struct hid_parser {
 	struct hid_global     global;
 	struct hid_global     global_stack[HID_GLOBAL_STACK_SIZE];
@@ -540,6 +543,7 @@
 	unsigned              collection_stack[HID_COLLECTION_STACK_SIZE];
 	unsigned              collection_stack_ptr;
 	struct hid_device    *device;
+	unsigned              scan_flags;
 };
 
 struct hid_class_descriptor {