HID: multitouch: fix protocol for Elo panels

The previous protocol was nearly working, but when several fingers were
present on the sensor, those that were not moving were not updated
in the next report, introducing a lot of releases.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>

Conflicts:
	drivers/hid/hid-multitouch.c
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-multitouch.c

@@ -116,6 +116,7 @@ struct mt_device {
 #define MT_CLS_INRANGE_CONTACTNUMBER		0x0009
 #define MT_CLS_ALWAYS_TRUE			0x000a
 #define MT_CLS_DUAL_CONTACT_NUMBER		0x0010
+#define MT_CLS_DUAL_CONTACT_ID			0x0011
 
 /* vendor specific classes */
 #define MT_CLS_3M				0x0101
@@ -183,6 +184,11 @@ static struct mt_class mt_classes[] = {
 			MT_QUIRK_CONTACT_CNT_ACCURATE |
 			MT_QUIRK_SLOT_IS_CONTACTNUMBER,
 		.maxcontacts = 2 },
+	{ .name = MT_CLS_DUAL_CONTACT_ID,
+		.quirks = MT_QUIRK_ALWAYS_VALID |
+			MT_QUIRK_CONTACT_CNT_ACCURATE |
+			MT_QUIRK_SLOT_IS_CONTACTID,
+		.maxcontacts = 2 },
 
 	/*
 	 * vendor specific classes
@@ -1040,7 +1046,7 @@ static const struct hid_device_id mt_devices[] = {
 			USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_72C4) },
 
 	/* Elo TouchSystems IntelliTouch Plus panel */
-	{ .driver_data = MT_CLS_DUAL_NSMU_CONTACTID,
+	{ .driver_data = MT_CLS_DUAL_CONTACT_ID,
 		MT_USB_DEVICE(USB_VENDOR_ID_ELO,
 			USB_DEVICE_ID_ELO_TS2515) },