input: add MT_TOOL_DIAL

A dial is a tool you place on a multitouch surface which reports its
orientation or a relative angle of rotation when rotating its knob.

Some examples are the Dell Totem (on the Canvas 27"), the Microsoft Dial,
or the Griffin Powermate, though the later can't be put on a touch surface.

We give some extra space to account for other types of fingers if we need
(MT_TOOL_THUMB)

Slightly change the documentation to not make it mandatory to update each
MT_TOOL we add.

Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 5 insertions, 4 deletions

diff --git a/include/uapi/linux/input.h b/include/uapi/linux/input.h
index 7288a7c573cc..fb78f6f500f3 100644
--- a/include/uapi/linux/input.h
+++ b/include/uapi/linux/input.h
@@ -270,10 +270,11 @@ struct input_mask {
 /*
  * MT_TOOL types
  */
-#define MT_TOOL_FINGER          0
-#define MT_TOOL_PEN             1
-#define MT_TOOL_PALM            2
-#define MT_TOOL_MAX             2
+#define MT_TOOL_FINGER          0x00
+#define MT_TOOL_PEN             0x01
+#define MT_TOOL_PALM            0x02
+#define MT_TOOL_DIAL            0x0a
+#define MT_TOOL_MAX             0x0f
 
 /*
  * Values describing the status of a force-feedback effect