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Commit d4b347b2 authored by Seth Forshee's avatar Seth Forshee Committed by Dmitry Torokhov
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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: default avatarSeth Forshee <seth.forshee@canonical.com>
Acked-by: default avatarChase Douglas <chase.douglas@canonical.com>
Signed-off-by: default avatarDmitry Torokhov <dtor@mail.ru>
parent 5a6c865d

Documentation/input/alps.txt

0 → 100644
+75 −0
Original line number Diff line number Diff line 
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

drivers/input/mouse/alps.c

+1 −36
Original line number Diff line number Diff line
@@ -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)