Input: estimate number of events per packet

Calculate a default based on the number of ABS axes, REL axes,
and MT slots for the device during input device registration.

Signed-off-by: Jeff Brown <jeffbrown@android.com>
Reviewed-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/include/linux/input/mt.h b/include/linux/input/mt.h
index b3ac06a..318bb82 100644
--- a/include/linux/input/mt.h
+++ b/include/linux/input/mt.h
@@ -48,6 +48,12 @@
 	input_event(dev, EV_ABS, ABS_MT_SLOT, slot);
 }
 
+static inline bool input_is_mt_axis(int axis)
+{
+	return axis == ABS_MT_SLOT ||
+		(axis >= ABS_MT_FIRST && axis <= ABS_MT_LAST);
+}
+
 void input_mt_report_slot_state(struct input_dev *dev,
 				unsigned int tool_type, bool active);