Input: atmel_mxt_ts - handle multiple input reports in one message

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
Acked-by: Benson Leung <bleung@chromium.org>
Acked-by: Yufeng Shen <miletus@chromium.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/touchscreen/atmel_mxt_ts.c

@@ -654,6 +654,12 @@ static void mxt_input_button(struct mxt_data *data, struct mxt_message *message)
 	}
 }
 
+static void mxt_input_sync(struct input_dev *input_dev)
+{
+	input_mt_report_pointer_emulation(input_dev, false);
+	input_sync(input_dev);
+}
+
 static void mxt_input_touchevent(struct mxt_data *data,
 				      struct mxt_message *message, int id)
 {
@@ -667,10 +673,12 @@ static void mxt_input_touchevent(struct mxt_data *data,
 
 	x = (message->message[1] << 4) | ((message->message[3] >> 4) & 0xf);
 	y = (message->message[2] << 4) | ((message->message[3] & 0xf));
+
+	/* Handle 10/12 bit switching */
 	if (data->max_x < 1024)
-		x = x >> 2;
+		x >>= 2;
 	if (data->max_y < 1024)
-		y = y >> 2;
+		y >>= 2;
 
 	area = message->message[4];
 	amplitude = message->message[5];
@@ -689,14 +697,28 @@ static void mxt_input_touchevent(struct mxt_data *data,
 		x, y, area, amplitude);
 
 	input_mt_slot(input_dev, id);
-	input_mt_report_slot_state(input_dev, MT_TOOL_FINGER,
-				   status & MXT_T9_DETECT);
 
 	if (status & MXT_T9_DETECT) {
+		/*
+		 * Multiple bits may be set if the host is slow to read
+		 * the status messages, indicating all the events that
+		 * have happened.
+		 */
+		if (status & MXT_T9_RELEASE) {
+			input_mt_report_slot_state(input_dev,
+						   MT_TOOL_FINGER, 0);
+			mxt_input_sync(input_dev);
+		}
+
+		/* Touch active */
+		input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, 1);
 		input_report_abs(input_dev, ABS_MT_POSITION_X, x);
 		input_report_abs(input_dev, ABS_MT_POSITION_Y, y);
 		input_report_abs(input_dev, ABS_MT_PRESSURE, amplitude);
 		input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR, area);
+	} else {
+		/* Touch no longer active, close out slot */
+		input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, 0);
 	}
 }
 
@@ -754,10 +776,8 @@ static irqreturn_t mxt_process_messages_until_invalid(struct mxt_data *data)
 		}
 	} while (reportid != 0xff);
 
-	if (update_input) {
-		input_mt_report_pointer_emulation(data->input_dev, false);
-		input_sync(data->input_dev);
-	}
+	if (update_input)
+		mxt_input_sync(data->input_dev);
 
 	return IRQ_HANDLED;
 }