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>
This commit is contained in:
Seth Forshee 2011-11-07 19:53:15 -08:00 committed by Dmitry Torokhov
parent 5a6c865d98
commit d4b347b29b
2 changed files with 76 additions and 36 deletions

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@ -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

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@ -67,42 +67,7 @@ static const struct alps_model_info alps_model_data[] = {
* isn't valid per PS/2 spec.
*/
/*
* 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 - 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
*
* CAPITALS = stick, miniscules = touchpad
*
* ?'s can have different meanings on different models,
* such as wheel rotation, extra buttons, stick buttons
* on a dualpoint, etc.
*/
/* Packet formats are described in Documentation/input/alps.txt */
static bool alps_is_valid_first_byte(const struct alps_model_info *model,
unsigned char data)