Input: alps - use standard contact tracking instead of DIY

When there are 2 fingers on the pad we don't know which one is which, so
use input_mt_assign_slots to make sure the right set of coordinates ends
up in the right slot.

Besides ensuring things end up in the right slot, this also results in a
nice cleanup, since sync_frame also handles non mt position and btn_touch
reporting.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/mouse/alps.c

@@ -419,25 +419,26 @@ static int alps_process_bitmap(struct alps_data *priv,
 	return fingers;
 }
 
-static void alps_set_slot(struct input_dev *dev, int slot, bool active,
-			  int x, int y)
+static void alps_set_slot(struct input_dev *dev, int slot, int x, int y)
 {
 	input_mt_slot(dev, slot);
-	input_mt_report_slot_state(dev, MT_TOOL_FINGER, active);
-	if (active) {
-		input_report_abs(dev, ABS_MT_POSITION_X, x);
-		input_report_abs(dev, ABS_MT_POSITION_Y, y);
-	}
+	input_mt_report_slot_state(dev, MT_TOOL_FINGER, true);
+	input_report_abs(dev, ABS_MT_POSITION_X, x);
+	input_report_abs(dev, ABS_MT_POSITION_Y, y);
 }
 
-static void alps_report_semi_mt_data(struct psmouse *psmouse, int num_fingers)
+static void alps_report_mt_data(struct psmouse *psmouse, int n)
 {
 	struct alps_data *priv = psmouse->private;
 	struct input_dev *dev = psmouse->dev;
 	struct alps_fields *f = &priv->f;
+	int i, slot[MAX_TOUCHES];
+
+	input_mt_assign_slots(dev, slot, f->mt, n);
+	for (i = 0; i < n; i++)
+		alps_set_slot(dev, slot[i], f->mt[i].x, f->mt[i].y);
 
-	alps_set_slot(dev, 0, num_fingers != 0, f->mt[0].x, f->mt[0].y);
-	alps_set_slot(dev, 1, num_fingers == 2, f->mt[1].x, f->mt[1].y);
+	input_mt_sync_frame(dev);
 }
 
 static void alps_process_trackstick_packet_v3(struct psmouse *psmouse)
@@ -674,12 +675,7 @@ static void alps_process_touchpad_packet_v3_v5(struct psmouse *psmouse)
 		fingers = f->pressure > 0 ? 1 : 0;
 	}
 
-	if (f->pressure >= 64)
-		input_report_key(dev, BTN_TOUCH, 1);
-	else
-		input_report_key(dev, BTN_TOUCH, 0);
-
-	alps_report_semi_mt_data(psmouse, fingers);
+	alps_report_mt_data(psmouse, (fingers <= 2) ? fingers : 1);
 
 	input_mt_report_finger_count(dev, fingers);
 
@@ -687,10 +683,6 @@ static void alps_process_touchpad_packet_v3_v5(struct psmouse *psmouse)
 	input_report_key(dev, BTN_RIGHT, f->right);
 	input_report_key(dev, BTN_MIDDLE, f->middle);
 
-	if (f->pressure > 0) {
-		input_report_abs(dev, ABS_X, f->st.x);
-		input_report_abs(dev, ABS_Y, f->st.y);
-	}
 	input_report_abs(dev, ABS_PRESSURE, f->pressure);
 
 	input_sync(dev);
@@ -853,22 +845,13 @@ static void alps_process_packet_v4(struct psmouse *psmouse)
 		fingers = f->fingers;
 	}
 
-	if (f->pressure >= 64)
-		input_report_key(dev, BTN_TOUCH, 1);
-	else
-		input_report_key(dev, BTN_TOUCH, 0);
-
-	alps_report_semi_mt_data(psmouse, fingers);
+	alps_report_mt_data(psmouse, (fingers <= 2) ? fingers : 1);
 
 	input_mt_report_finger_count(dev, fingers);
 
 	input_report_key(dev, BTN_LEFT, f->left);
 	input_report_key(dev, BTN_RIGHT, f->right);
 
-	if (f->pressure > 0) {
-		input_report_abs(dev, ABS_X, f->st.x);
-		input_report_abs(dev, ABS_Y, f->st.y);
-	}
 	input_report_abs(dev, ABS_PRESSURE, f->pressure);
 
 	input_sync(dev);
@@ -2003,17 +1986,14 @@ static void alps_set_abs_params_st(struct alps_data *priv,
 static void alps_set_abs_params_mt(struct alps_data *priv,
 				   struct input_dev *dev1)
 {
-	set_bit(INPUT_PROP_SEMI_MT, dev1->propbit);
-	input_mt_init_slots(dev1, 2, 0);
 	input_set_abs_params(dev1, ABS_MT_POSITION_X, 0, priv->x_max, 0, 0);
 	input_set_abs_params(dev1, ABS_MT_POSITION_Y, 0, priv->y_max, 0, 0);
 
-	set_bit(BTN_TOOL_DOUBLETAP, dev1->keybit);
+	input_mt_init_slots(dev1, MAX_TOUCHES, INPUT_MT_POINTER |
+		INPUT_MT_DROP_UNUSED | INPUT_MT_TRACK | INPUT_MT_SEMI_MT);
+
 	set_bit(BTN_TOOL_TRIPLETAP, dev1->keybit);
 	set_bit(BTN_TOOL_QUADTAP, dev1->keybit);
-
-	input_set_abs_params(dev1, ABS_X, 0, priv->x_max, 0, 0);
-	input_set_abs_params(dev1, ABS_Y, 0, priv->y_max, 0, 0);
 }
 
 int alps_init(struct psmouse *psmouse)