HID: wacom: Bluetooth IRQ for Intuos Pro should handle prox/range

The prox/range bits included in the Bluetooth reports from the Intuos Pro
were being ignored, leading to two issues. Firstly, the pen would never
announce a BTN_TOOL_PEN event with value 0, leaving userspace to believe
the pen was always active. Secondly, the driver would continue to send
events for data while the packet's "prox" bit was clear. This can lead
to sudden incorrect pointer jumps if the pen is slowly moved away from
the tablet surface.
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Reviewed-by: Ping Cheng <ping.cheng@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/wacom_wac.c

@@ -1211,29 +1211,34 @@ static void wacom_intuos_pro2_bt_pen(struct wacom_wac *wacom)
 
 	for (i = 0; i < pen_frames; i++) {
 		unsigned char *frame = &data[i*pen_frame_len + 1];
+		bool valid = frame[0] & 0x80;
+		bool prox = frame[0] & 0x40;
+		bool range = frame[0] & 0x20;
 
-		if (!(frame[0] & 0x80))
+		if (!valid)
 			continue;
 
+		if (range) {
 			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_PRESSURE, get_unaligned_le16(&frame[5]));
 			input_report_abs(pen_input, ABS_TILT_X, frame[7]);
 			input_report_abs(pen_input, ABS_TILT_Y, frame[8]);
 			input_report_abs(pen_input, ABS_Z, get_unaligned_le16(&frame[9]));
 			input_report_abs(pen_input, ABS_WHEEL, get_unaligned_le16(&frame[11]));
-		input_report_abs(pen_input, ABS_DISTANCE, frame[13]);
+		}
+		input_report_abs(pen_input, ABS_PRESSURE, get_unaligned_le16(&frame[5]));
+		input_report_abs(pen_input, ABS_DISTANCE, range ? frame[13] : wacom->features.distance_max);
 
 		input_report_key(pen_input, BTN_TOUCH, frame[0] & 0x01);
 		input_report_key(pen_input, BTN_STYLUS, frame[0] & 0x02);
 		input_report_key(pen_input, BTN_STYLUS2, frame[0] & 0x04);
 
-		input_report_key(pen_input, wacom->tool[0], 1);
+		input_report_key(pen_input, wacom->tool[0], prox);
 		input_event(pen_input, EV_MSC, MSC_SERIAL, wacom->serial[0]);
 		input_report_abs(pen_input, ABS_MISC,
 				 wacom_intuos_id_mangle(wacom->id[0])); /* report tool id */
 
-		wacom->shared->stylus_in_proximity = frame[0] & 0x40;
+		wacom->shared->stylus_in_proximity = prox;
 
 		input_sync(pen_input);
 	}