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authorSeth Forshee <seth.forshee@canonical.com>2011-11-07 19:53:15 -0800
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2011-11-07 22:22:09 -0800
commitd4b347b29b4d14647c7394f7167bf6785dc98e50 (patch)
tree82f8e1c35bba7f2ba2b6ad0b930a2dea70d009a8 /Documentation/input
parent5a6c865d9861efdd066db1b5da491ebc2ff5926d (diff)
downloadlinux-linaro-stable-d4b347b29b4d14647c7394f7167bf6785dc98e50.tar.gz
Input: ALPS - move protocol information to Documentation
In preparation for new protocol support, move the protocol information currently documented in alps.c to Documentation/input/alps.txt, where it can be expanded without cluttering up the driver. Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Acked-by: Chase Douglas <chase.douglas@canonical.com> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
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+ALPS Touchpad Protocol
+----------------------
+
+Introduction
+------------
+
+Currently the ALPS touchpad driver supports two protocol versions in use by
+ALPS touchpads, the "old" and "new" protocol versions. Fundamentally these
+differ only in the format of their event packets (in reality many features may
+be found on new protocol devices that aren't found on the old protocol
+devices, but these are handled transparently as feature differences rather
+than protocol differences).
+
+Detection
+---------
+
+All ALPS touchpads should respond to the "E6 report" command sequence:
+E8-E6-E6-E6-E9. An ALPS touchpad should respond with either 00-00-0A or
+00-00-64.
+
+If the E6 report is successful, the touchpad model is identified using the "E7
+report" sequence: E8-E7-E7-E7-E9. The response is the model signature and is
+matched against known models in the alps_model_data_array.
+
+Packet Format
+-------------
+
+In the following tables, the following notation us used.
+
+ CAPITALS = stick, miniscules = touchpad
+
+?'s can have different meanings on different models, such as wheel rotation,
+extra buttons, stick buttons on a dualpoint, etc.
+
+PS/2 packet format
+------------------
+
+ byte 0: 0 0 YSGN XSGN 1 M R L
+ byte 1: X7 X6 X5 X4 X3 X2 X1 X0
+ byte 2: Y7 Y6 Y5 Y4 Y3 Y2 Y1 Y0
+
+Note that the device never signals overflow condition.
+
+ALPS Absolute Mode - Old Format
+-------------------------------
+
+ byte 0: 1 0 0 0 1 x9 x8 x7
+ byte 1: 0 x6 x5 x4 x3 x2 x1 x0
+ byte 2: 0 ? ? l r ? fin ges
+ byte 3: 0 ? ? ? ? y9 y8 y7
+ byte 4: 0 y6 y5 y4 y3 y2 y1 y0
+ byte 5: 0 z6 z5 z4 z3 z2 z1 z0
+
+ALPS Absolute Mode - New Format
+-------------------------------
+
+ byte 0: 1 ? ? ? 1 ? ? ?
+ byte 1: 0 x6 x5 x4 x3 x2 x1 x0
+ byte 2: 0 x10 x9 x8 x7 ? fin ges
+ byte 3: 0 y9 y8 y7 1 M R L
+ byte 4: 0 y6 y5 y4 y3 y2 y1 y0
+ byte 5: 0 z6 z5 z4 z3 z2 z1 z0
+
+Dualpoint device -- interleaved packet format
+---------------------------------------------
+
+ byte 0: 1 1 0 0 1 1 1 1
+ byte 1: 0 x6 x5 x4 x3 x2 x1 x0
+ byte 2: 0 x10 x9 x8 x7 0 fin ges
+ byte 3: 0 0 YSGN XSGN 1 1 1 1
+ byte 4: X7 X6 X5 X4 X3 X2 X1 X0
+ byte 5: Y7 Y6 Y5 Y4 Y3 Y2 Y1 Y0
+ byte 6: 0 y9 y8 y7 1 m r l
+ byte 7: 0 y6 y5 y4 y3 y2 y1 y0
+ byte 8: 0 z6 z5 z4 z3 z2 z1 z0