The newly released HID protocol for win8 input devices is capable of
transmitting the same information found in the Apple HID and Linux MT
protocols. In addition, it includes an extension useful for touch
alignment. This patch completes the MT protocol with the
ABS_MT_APPROACH_X/Y events, and documents how to map win8 devices.

Signed-off-by: Henrik Rydberg <redacted>
---
Hi all,

In response to the win8 HID protocol and Benjamin's work on this, here
is a first draft of the needed extension to the MT protocol. I am
cc:ing the usual suspects, as this will affect userland. Comments and
criticism expected. :-)

Cheers,
Henrik

 Documentation/input/multi-touch-protocol.txt |   35 +++++++++++++++++++++++++-
 include/linux/input.h                        |    4 ++-
 2 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/Documentation/input/multi-touch-protocol.txt b/Documentation/input/multi-touch-protocol.txt
index 543101c..504ca6d 100644
--- a/Documentation/input/multi-touch-protocol.txt
+++ b/Documentation/input/multi-touch-protocol.txt

@@ -252,6 +254,9 @@ can distinguish between the two axis, but not (uniquely) any values in
 between. In such cases, the range of ABS_MT_ORIENTATION should be [0, 1]
 [4].
 
+For devices capable of 360 degree orientation, the reported orientation
+should be twice the given range.