Input: Break out MT data

Move all MT-related things to a separate place. This saves some
bytes for non-mt input devices, and prepares for new MT features.

Reviewed-and-tested-by: Benjamin Tissoires <benjamin.tissoires@enac.fr>
Tested-by: Ping Cheng <pingc@wacom.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

1 files changed, 16 insertions, 2 deletions

diff --git a/include/linux/input/mt.h b/include/linux/input/mt.h
index f86737586e1..63458bced77 100644
--- a/include/linux/input/mt.h
+++ b/include/linux/input/mt.h
@@ -23,6 +23,20 @@ struct input_mt_slot {
         int abs[ABS_MT_LAST - ABS_MT_FIRST + 1];
 };
 
+/**
+ * struct input_mt - state of tracked contacts
+ * @trkid: stores MT tracking ID for the next contact
+ * @num_slots: number of MT slots the device uses
+ * @slot: MT slot currently being transmitted
+ * @slots: array of slots holding current values of tracked contacts
+ */
+struct input_mt {
+        int trkid;
+        int num_slots;
+        int slot;
+        struct input_mt_slot slots[];
+};
+
 static inline void input_mt_set_value(struct input_mt_slot *slot,
                                       unsigned code, int value)
 {
@@ -38,9 +52,9 @@ static inline int input_mt_get_value(const struct input_mt_slot *slot,
 int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots);
 void input_mt_destroy_slots(struct input_dev *dev);
 
-static inline int input_mt_new_trkid(struct input_dev *dev)
+static inline int input_mt_new_trkid(struct input_mt *mt)
 {
-        return dev->trkid++ & TRKID_MAX;
+        return mt->trkid++ & TRKID_MAX;
 }
 
 static inline void input_mt_slot(struct input_dev *dev, int slot)