HID: wacom: Add tilt reporting for Intuos4 WL

Tile is reported to input subsystem as reported by the device without
any modifications. It means that tilt X/Y range is 0 to 127 and it's
not centered on zero.

Signed-off-by: Przemo Firszt <przemo@firszt.eu>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-wacom.c

@@ -363,6 +363,7 @@ static void wacom_i4_parse_pen_report(struct wacom_data *wdata,
 {
 	__u16 x, y, pressure;
 	__u8 distance;
+	__u8 tilt_x, tilt_y;
 
 	switch (data[1]) {
 	case 0x80: /* Out of proximity report */
@@ -399,6 +400,8 @@ static void wacom_i4_parse_pen_report(struct wacom_data *wdata,
 		pressure = (data[6] << 3) | ((data[7] & 0xC0) >> 5)
 			| (data[1] & 0x01);
 		distance = (data[9] >> 2) & 0x3f;
+		tilt_x = ((data[7] << 1) & 0x7e) | (data[8] >> 7);
+		tilt_y = data[8] & 0x7f;
 
 		input_report_key(input, BTN_TOUCH, pressure > 1);
 
@@ -409,6 +412,8 @@ static void wacom_i4_parse_pen_report(struct wacom_data *wdata,
 		input_report_abs(input, ABS_Y, y);
 		input_report_abs(input, ABS_PRESSURE, pressure);
 		input_report_abs(input, ABS_DISTANCE, distance);
+		input_report_abs(input, ABS_TILT_X, tilt_x);
+		input_report_abs(input, ABS_TILT_Y, tilt_y);
 		input_report_abs(input, ABS_MISC, wdata->id);
 		input_event(input, EV_MSC, MSC_SERIAL, wdata->serial);
 		input_report_key(input, wdata->tool, 1);
@@ -548,6 +553,8 @@ static int wacom_input_mapped(struct hid_device *hdev, struct hid_input *hi,
 		input_set_abs_params(input, ABS_Y, 0, 25400, 4, 0);
 		input_set_abs_params(input, ABS_PRESSURE, 0, 2047, 0, 0);
 		input_set_abs_params(input, ABS_DISTANCE, 0, 63, 0, 0);
+		input_set_abs_params(input, ABS_TILT_X, 0, 127, 0, 0);
+		input_set_abs_params(input, ABS_TILT_Y, 0, 127, 0, 0);
 		break;
 	}