Input: synaptics - report multi-taps only if supported by the device

According to Section 2.4.4 of the Synaptics TouchPad Interfacing
Guide, bit 2 specifies if multi-finger detection is provided by
the touchpad. Thus, only set BTN_TOOL_DOUBLETAP and
BTN_TOOL_TRIPLETAP if the device actually supports it.
Signed-off-by: Peter Hutterer <peter.hutterer@redhat.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/mouse/synaptics.c

@@ -445,12 +445,14 @@ static void synaptics_process_packet(struct psmouse *psmouse)
 
 	input_report_abs(dev, ABS_TOOL_WIDTH, finger_width);
 	input_report_key(dev, BTN_TOOL_FINGER, num_fingers == 1);
-	input_report_key(dev, BTN_TOOL_DOUBLETAP, num_fingers == 2);
-	input_report_key(dev, BTN_TOOL_TRIPLETAP, num_fingers == 3);
-
 	input_report_key(dev, BTN_LEFT, hw.left);
 	input_report_key(dev, BTN_RIGHT, hw.right);
 
+	if (SYN_CAP_MULTIFINGER(priv->capabilities)) {
+		input_report_key(dev, BTN_TOOL_DOUBLETAP, num_fingers == 2);
+		input_report_key(dev, BTN_TOOL_TRIPLETAP, num_fingers == 3);
+	}
+
 	if (SYN_CAP_MIDDLE_BUTTON(priv->capabilities))
 		input_report_key(dev, BTN_MIDDLE, hw.middle);
 
@@ -543,12 +545,14 @@ static void set_input_params(struct input_dev *dev, struct synaptics_data *priv)
 	set_bit(EV_KEY, dev->evbit);
 	set_bit(BTN_TOUCH, dev->keybit);
 	set_bit(BTN_TOOL_FINGER, dev->keybit);
-	set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
-	set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);
-
 	set_bit(BTN_LEFT, dev->keybit);
 	set_bit(BTN_RIGHT, dev->keybit);
 
+	if (SYN_CAP_MULTIFINGER(priv->capabilities)) {
+		set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
+		set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);
+	}
+
 	if (SYN_CAP_MIDDLE_BUTTON(priv->capabilities))
 		set_bit(BTN_MIDDLE, dev->keybit);