HID: multitouch: handle external buttons for Precision Touchpads
According to https://msdn.microsoft.com/en-us/library/windows/hardware/mt604195(v=vs.85).aspx
external buttons have some weird usage mapping:
- Button 2 Indicates Button State for external button for primary
(default left) clicking.
- Button 3 Indicates Button State for external button for secondary
(default right) clicking.
So in the current state, the buttons are mapped to right and middle.
Move the usage by one to correctly map the external buttons.
Tested-by: Chris Chiu <chiu@endlessm.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index fb6f1f4..a65a4c5 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -567,6 +567,14 @@
case HID_UP_BUTTON:
code = BTN_MOUSE + ((usage->hid - 1) & HID_USAGE);
+ /*
+ * MS PTP spec says that external buttons left and right have
+ * usages 2 and 3.
+ */
+ if (cls->name == MT_CLS_WIN_8 &&
+ field->application == HID_DG_TOUCHPAD &&
+ (usage->hid & HID_USAGE) > 1)
+ code--;
hid_map_usage(hi, usage, bit, max, EV_KEY, code);
input_set_capability(hi->input, EV_KEY, code);
return 1;