Patch "HID: wacom: Correct coordinate system of touchring and pen twist" has been added to the 4.13-stable tree

@@ -1227,11 +1227,17 @@ static void wacom_intuos_pro2_bt_pen(str
 			continue;
 
 		if (range) {
+			/* Fix rotation alignment: userspace expects zero at left */
+			int16_t rotation = (int16_t)get_unaligned_le16(&frame[9]);
+			rotation += 1800/4;
+			if (rotation > 899)
+				rotation -= 1800;
+
 			input_report_abs(pen_input, ABS_X, get_unaligned_le16(&frame[1]));
 			input_report_abs(pen_input, ABS_Y, get_unaligned_le16(&frame[3]));
 			input_report_abs(pen_input, ABS_TILT_X, (char)frame[7]);
 			input_report_abs(pen_input, ABS_TILT_Y, (char)frame[8]);
-			input_report_abs(pen_input, ABS_Z, (int16_t)get_unaligned_le16(&frame[9]));
+			input_report_abs(pen_input, ABS_Z, rotation);
 			input_report_abs(pen_input, ABS_WHEEL, get_unaligned_le16(&frame[11]));
 		}
 		input_report_abs(pen_input, ABS_PRESSURE, get_unaligned_le16(&frame[5]));

@@ -1319,12 +1325,19 @@ static void wacom_intuos_pro2_bt_pad(str
 	unsigned char *data = wacom->data;
 
 	int buttons = (data[282] << 1) | ((data[281] >> 6) & 0x01);
-	int ring = data[285];
-	int prox = buttons | (ring & 0x80);
+	int ring = data[285] & 0x7F;
+	bool ringstatus = data[285] & 0x80;
+	bool prox = buttons || ringstatus;
+
+	/* Fix touchring data: userspace expects 0 at left and increasing clockwise */
+	ring = 71 - ring;
+	ring += 3*72/16;
+	if (ring > 71)
+		ring -= 72;
 
 	wacom_report_numbered_buttons(pad_input, 9, buttons);
 
-	input_report_abs(pad_input, ABS_WHEEL, (ring & 0x80) ? (ring & 0x7f) : 0);
+	input_report_abs(pad_input, ABS_WHEEL, ringstatus ? ring : 0);
 
 	input_report_key(pad_input, wacom->tool[1], prox ? 1 : 0);
 	input_report_abs(pad_input, ABS_MISC, prox ? PAD_DEVICE_ID : 0);

@@ -1616,6 +1629,20 @@ static int wacom_tpc_irq(struct wacom_wa
 	return 0;
 }
 
+static int wacom_offset_rotation(struct input_dev *input, struct hid_usage *usage,
+				 int value, int num, int denom)
+{
+	struct input_absinfo *abs = &input->absinfo[usage->code];
+	int range = (abs->maximum - abs->minimum + 1);
+
+	value += num*range/denom;
+	if (value > abs->maximum)
+		value -= range;
+	else if (value < abs->minimum)
+		value += range;
+	return value;
+}
+
 int wacom_equivalent_usage(int usage)
 {
 	if ((usage & HID_USAGE_PAGE) == WACOM_HID_UP_WACOMDIGITIZER) {

@@ -1898,6 +1925,7 @@ static void wacom_wac_pad_event(struct h
 	unsigned equivalent_usage = wacom_equivalent_usage(usage->hid);
 	int i;
 	bool is_touch_on = value;
+	bool do_report = false;
 
 	/*
 	 * Avoid reporting this event and setting inrange_state if this usage

@@ -1912,6 +1940,29 @@ static void wacom_wac_pad_event(struct h
 	}
 
 	switch (equivalent_usage) {
+	case WACOM_HID_WD_TOUCHRING:
+		/*
+		 * Userspace expects touchrings to increase in value with
+		 * clockwise gestures and have their zero point at the
+		 * tablet's left. HID events "should" be clockwise-
+		 * increasing and zero at top, though the MobileStudio
+		 * Pro and 2nd-gen Intuos Pro don't do this...
+		 */
+		if (hdev->vendor == 0x56a &&
+		    (hdev->product == 0x34d || hdev->product == 0x34e ||  /* MobileStudio Pro */
+		     hdev->product == 0x357 || hdev->product == 0x358)) { /* Intuos Pro 2 */
+			value = (field->logical_maximum - value);
+
+			if (hdev->product == 0x357 || hdev->product == 0x358)
+				value = wacom_offset_rotation(input, usage, value, 3, 16);
+			else if (hdev->product == 0x34d || hdev->product == 0x34e)
+				value = wacom_offset_rotation(input, usage, value, 1, 2);
+		}
+		else {
+			value = wacom_offset_rotation(input, usage, value, 1, 4);
+		}
+		do_report = true;
+		break;
 	case WACOM_HID_WD_TOUCHRINGSTATUS:
 		if (!value)
 			input_event(input, usage->type, usage->code, 0);

@@ -1945,10 +1996,14 @@ static void wacom_wac_pad_event(struct h
 					 value, i);
 		 /* fall through*/
 	default:
+		do_report = true;
+		break;
+	}
+
+	if (do_report) {
 		input_event(input, usage->type, usage->code, value);
 		if (value)
 			wacom_wac->hid_data.pad_input_event_flag = true;
-		break;
 	}
 }
 

@@ -2089,6 +2144,14 @@ static void wacom_wac_pen_event(struct h
 		wacom_wac->serial[0] = (wacom_wac->serial[0] & ~0xFFFFFFFFULL);
 		wacom_wac->serial[0] |= (__u32)value;
 		return;
+	case HID_DG_TWIST:
+		/*
+		 * Userspace expects pen twist to have its zero point when
+		 * the buttons/finger is on the tablet's left. HID values
+		 * are zero when buttons are toward the top.
+		 */
+		value = wacom_offset_rotation(input, usage, value, 1, 4);
+		break;
 	case WACOM_HID_WD_SENSE:
 		wacom_wac->hid_data.sense_state = value;
 		return;