HID: wacom: generic: Add support for vendor-defined "Fingerwheel" usage

The airbrush fingerwheel does not have a usage that corresponds cleanly
with a standard HID usage, so we add explicit support for it via its
vendor-defined usage.
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/wacom_wac.c

@@ -1539,6 +1539,9 @@ static void wacom_wac_pen_usage_mapping(struct hid_device *hdev,
 	case HID_DG_TOOLSERIALNUMBER:
 		wacom_map_usage(input, usage, field, EV_MSC, MSC_SERIAL, 0);
 		break;
+	case WACOM_HID_WD_FINGERWHEEL:
+		wacom_map_usage(input, usage, field, EV_ABS, ABS_WHEEL, 0);
+		break;
 	}
 }
 

drivers/hid/wacom_wac.h

@@ -89,6 +89,7 @@
 #define WACOM_HID_SP_DIGITIZERINFO      0x00100000
 #define WACOM_HID_WD_DIGITIZER          (WACOM_HID_UP_WACOMDIGITIZER | 0x01)
 #define WACOM_HID_WD_DISTANCE           (WACOM_HID_UP_WACOMDIGITIZER | 0x0132)
+#define WACOM_HID_WD_FINGERWHEEL        (WACOM_HID_UP_WACOMDIGITIZER | 0x0d03)
 #define WACOM_HID_WD_DATAMODE           (WACOM_HID_UP_WACOMDIGITIZER | 0x1002)
 #define WACOM_HID_UP_G9                 0xff090000
 #define WACOM_HID_G9_PEN                (WACOM_HID_UP_G9 | 0x02)