Input: wacom_serial4 - add support for Wacom ArtPad II tablet

commit 44fc95e218a09d7966a9d448941fdb003f6bb69f upstream.

Tablet initially begins communicating at 9600 baud, so this command
should be used to connect to the device:

    $ inputattach --daemon --baud 9600 --wacom_iv /dev/ttyS0

https://github.com/linuxwacom/xf86-input-wacom/issues/40

Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/input/tablet/wacom_serial4.c

@@ -187,6 +187,7 @@ enum {
 	MODEL_DIGITIZER_II	= 0x5544, /* UD */
 	MODEL_GRAPHIRE		= 0x4554, /* ET */
 	MODEL_PENPARTNER	= 0x4354, /* CT */
+	MODEL_ARTPAD_II		= 0x4B54, /* KT */
 };
 
 static void wacom_handle_model_response(struct wacom *wacom)
@@ -245,6 +246,7 @@ static void wacom_handle_model_response(struct wacom *wacom)
 		wacom->flags = F_HAS_STYLUS2 | F_HAS_SCROLLWHEEL;
 		break;
 
+	case MODEL_ARTPAD_II:
 	case MODEL_DIGITIZER_II:
 		wacom->dev->name = "Wacom Digitizer II";
 		wacom->dev->id.version = MODEL_DIGITIZER_II;