USB HID: Add ID for eGalax Multitouch used in JooJoo tablet

The JooJoo tablet (http://thejoojoo.com/) contains an "eGalax Inc. USB
TouchController", and this patch hooks it up to the egalax-touch driver.
Without the patch we don't get any cursor motion, since it comes through
Z/RX rather than X/Y.

(The egalax-touch driver does not yet generate a correct event sequence
for the "serial" protocol used by this device, though -- see the note
added to the code, which comes from research by Stéphane Chatty.)

Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Stéphane Chatty <chatty@enac.fr>
Signed-off-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-core.c

@@ -1299,6 +1299,7 @@ static const struct hid_device_id hid_blacklist[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_CYPRESS, USB_DEVICE_ID_CYPRESS_MOUSE) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_DRAGONRISE, 0x0006) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_DWAV, USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_DWAV, USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH1) },
 	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_BM084) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_EZKEY, USB_DEVICE_ID_BTC_8193) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_GAMERON, USB_DEVICE_ID_GAMERON_DUAL_PSX_ADAPTOR) },

drivers/hid/hid-egalax.c

@@ -159,6 +159,13 @@ static int egalax_event(struct hid_device *hid, struct hid_field *field,
 {
 	struct egalax_data *td = hid_get_drvdata(hid);
 
+	/* Note, eGalax has two product lines: the first is resistive and
+	 * uses a standard parallel multitouch protocol (product ID ==
+	 * 48xx).  The second is capacitive and uses an unusual "serial"
+	 * protocol with a different message for each multitouch finger
+	 * (product ID == 72xx).  We do not yet generate a correct event
+	 * sequence for the capacitive/serial protocol.
+	 */
 	if (hid->claimed & HID_CLAIMED_INPUT) {
 		struct input_dev *input = field->hidinput->input;
 
@@ -246,6 +253,8 @@ static void egalax_remove(struct hid_device *hdev)
 static const struct hid_device_id egalax_devices[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 			USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
+			USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH1) },
 	{ }
 };
 MODULE_DEVICE_TABLE(hid, egalax_devices);

drivers/hid/hid-ids.h

@@ -188,6 +188,7 @@
 #define USB_VENDOR_ID_DWAV		0x0eef
 #define USB_DEVICE_ID_EGALAX_TOUCHCONTROLLER	0x0001
 #define USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH	0x480d
+#define USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH1	0x720c
 
 #define USB_VENDOR_ID_ELECOM		0x056e
 #define USB_DEVICE_ID_ELECOM_BM084	0x0061