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| author | Seth Forshee <seth.forshee@canonical.com> | 2011-11-07 19:53:15 -0800 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2011-11-07 22:22:09 -0800 |
| commit | d4b347b29b4d14647c7394f7167bf6785dc98e50 (patch) | |
| tree | 82f8e1c35bba7f2ba2b6ad0b930a2dea70d009a8 /Documentation/input | |
| parent | 5a6c865d9861efdd066db1b5da491ebc2ff5926d (diff) | |
| download | lwn-d4b347b29b4d14647c7394f7167bf6785dc98e50.tar.gz lwn-d4b347b29b4d14647c7394f7167bf6785dc98e50.zip | |
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>
Diffstat (limited to 'Documentation/input')
| -rw-r--r-- | Documentation/input/alps.txt | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/Documentation/input/alps.txt b/Documentation/input/alps.txt new file mode 100644 index 000000000000..ab5478f92a2b --- /dev/null +++ b/Documentation/input/alps.txt @@ -0,0 +1,75 @@ +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 |