input/devices/alps.rst

8 ALPS touchpads, called versions 1, 2, 3, 4, 5, 6, 7 and 8.
11 integrated into a variety of laptops and netbooks.  These new touchpads
23 (Compatibility ID) definition as a way to uniquely identify the
24 different ALPS variants but there did not appear to be a 1:1 mapping.
32 E8-E6-E6-E6-E9. An ALPS touchpad should respond with either 00-00-0A or
45 The new ALPS touchpads have an E7 signature of 73-03-50 or 73-03-0A but
51 Protocol versions 3 and 4 have a command mode that is used to read and write
52 one-byte device registers in a 16-bit address space. The command sequence
54 with 88-07 followed by a third byte. This third byte can be used to determine
59 While in command mode, register addresses can be set by first sending a
61 address is sent one nibble at a time, where each nibble is encoded as a
68 register. Registers are written by writing the value one nibble at a time
87 extra buttons, stick buttons on a dualpoint, etc.
114  byte 5:  0   z6   z5   z4   z3   z2   z1   z0
126  byte 5:  0   z6   z5   z4   z3   z2   z1   z0
144  byte 5:   Y7   Y6   Y5   Y4   Y3   Y2   Y1   Y0
168  byte 5:    0   z6   z5   z4   z3   z2   z1   z0
174 bitmaps a given bit is set if there is a finger covering that position on the
184  byte 5:    0    1    ?    ?    ?    ?   f1   f0
186 This packet only appears after a position packet with the mt bit set, and
188 occasionally it's seen with only a single contact).
197  byte 5:    0    0    1    1    1    1    1    1
212  byte 5:    0   z6   z5   z4   z3   z2   z1   z0
216 The last two bytes represent a partial bitmap packet, with 3 full packets
217 required to construct a complete bitmap packet.  Once assembled, the 6-byte
225  byte 5:    0    0    0    0    0    0    0  y10
229  1) In the bitmap data, bit 6 of byte 0 serves as a sync byte to
230     identify the first fragment of a bitmap packet.
235  3) There doesn't seem to be a count of the contact points anywhere in the v4
236     protocol packets. Deriving a count of contact points must be done by
239  4) There is a 3 to 1 ratio of position packets to bitmap packets. Therefore
246 ALPS Absolute Mode - Protocol Version 5
249 decode.  It uses the same alps_process_touchpad_packet_v3 call with a
260  byte 5:    0   z6   z5   z4   z3   z2   z1   z0
269  byte 5:    0  x16  x15   x14 x13  x12  x11   x10
281  byte 5:    0    1    1    1    1    1    1    1
290  byte 5:   z7   z6   z5   z4   z3   z2   z1   z0
304  byte 5:  T&P    0   Z5   Z4   Z3   Z2   Z1   Z0
310  byte 0: NEW             L      1   X1-5      1      1   Y0-2   Y0-1   Y0-0
311  byte 1:             Y0-10   Y0-9   Y0-8   Y0-7   Y0-6   Y0-5   Y0-4   Y0-3
312  byte 2:             X0-11      1  X0-10   X0-9   X0-8   X0-7   X0-6   X0-5
314  byte 4: TWO         X1-10    TWO   X1-9   X1-8   X1-7   X1-6   X1-5   X1-4
315  byte 4: MULTI       X1-10    TWO   X1-9   X1-8   X1-7   X1-6   Y1-5      1
317  byte 5: TWO & NEW   Y1-10      0   Y1-9   Y1-8   Y1-7   Y1-6   Y1-5   Y1-4
318  byte 5: MULTI       Y1-10      0   Y1-9   Y1-8   Y1-7   Y1-6    F-1    F-0
327             so if a TWO packet is received and R = 1 then there are
329  TWO:       1: Two touches present, byte 0/4/5 are in TWO fmt
330             0: If byte 4 bit 0 is 1, then byte 0/4/5 are in MULTI fmt
331                otherwise byte 0 bit 4 must be set and byte 0/4/5 are
341 The packet type is given by the APD field, bits 4-5 of byte 3.
351  byte 5:    0    0    0    0    0    0    0    0
363  byte 5:  Zv6  Zv5  Zv4    0  Zv3  Zv2  Zv1  Zv0
376  byte 5: BY11 BY10  BY9    0  BY8  BY7  BY5  BY5
378 CONT: A 3-or-4 Finger packet is to follow
388  byte 5: BY11 BY10  BY9    0  BY8  BY7  BY5  BY5
390 OVF: 5th finger detected