Input: elantech - add v4 hardware support
v4 hardware is a true multitouch capable touchpad (up to 5 fingers).
The packet format is quite complex, please see protocol document for
reference.
Signed-off-by: JJ Ding <jj_ding@emc.com.tw>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/Documentation/input/elantech.txt b/Documentation/input/elantech.txt
index cee08ee..5602eb7 100644
--- a/Documentation/input/elantech.txt
+++ b/Documentation/input/elantech.txt
@@ -32,6 +32,12 @@
6.2 Native absolute mode 6 byte packet format
6.2.1 One/Three finger touch
6.2.2 Two finger touch
+ 7. Hardware version 4
+ 7.1 Registers
+ 7.2 Native absolute mode 6 byte packet format
+ 7.2.1 Status packet
+ 7.2.2 Head packet
+ 7.2.3 Motion packet
@@ -573,3 +579,167 @@
sends two 6 byte packets. The first packet contains data for the first finger,
the second packet has data for the second finger. So for two finger touch a
total of 12 bytes are sent.
+
+/////////////////////////////////////////////////////////////////////////////
+
+7. Hardware version 4
+ ==================
+
+7.1 Registers
+ ~~~~~~~~~
+* reg_07
+
+ bit 7 6 5 4 3 2 1 0
+ 0 0 0 0 0 0 0 A
+
+ A: 1 = enable absolute tracking
+
+7.2 Native absolute mode 6 byte packet format
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+v4 hardware is a true multitouch touchpad, capable of tracking up to 5 fingers.
+Unfortunately, due to PS/2's limited bandwidth, its packet format is rather
+complex.
+
+Whenever the numbers or identities of the fingers changes, the hardware sends a
+status packet to indicate how many and which fingers is on touchpad, followed by
+head packets or motion packets. A head packet contains data of finger id, finger
+position (absolute x, y values), width, and pressure. A motion packet contains
+two fingers' position delta.
+
+For example, when status packet tells there are 2 fingers on touchpad, then we
+can expect two following head packets. If the finger status doesn't change,
+the following packets would be motion packets, only sending delta of finger
+position, until we receive a status packet.
+
+One exception is one finger touch. when a status packet tells us there is only
+one finger, the hardware would just send head packets afterwards.
+
+7.2.1 Status packet
+ ~~~~~~~~~~~~~
+
+byte 0:
+
+ bit 7 6 5 4 3 2 1 0
+ . . . . 0 1 R L
+
+ L, R = 1 when Left, Right mouse button pressed
+
+byte 1:
+
+ bit 7 6 5 4 3 2 1 0
+ . . . ft4 ft3 ft2 ft1 ft0
+
+ ft4 ft3 ft2 ft1 ft0 ftn = 1 when finger n is on touchpad
+
+byte 2: not used
+
+byte 3:
+
+ bit 7 6 5 4 3 2 1 0
+ . . . 1 0 0 0 0
+
+ constant bits
+
+byte 4:
+
+ bit 7 6 5 4 3 2 1 0
+ p . . . . . . .
+
+ p = 1 for palm
+
+byte 5: not used
+
+7.2.2 Head packet
+ ~~~~~~~~~~~
+
+byte 0:
+
+ bit 7 6 5 4 3 2 1 0
+ w3 w2 w1 w0 0 1 R L
+
+ L, R = 1 when Left, Right mouse button pressed
+ w3..w0 = finger width (spans how many trace lines)
+
+byte 1:
+
+ bit 7 6 5 4 3 2 1 0
+ p7 p6 p5 p4 x11 x10 x9 x8
+
+byte 2:
+
+ bit 7 6 5 4 3 2 1 0
+ x7 x6 x5 x4 x3 x2 x1 x0
+
+ x11..x0 = absolute x value (horizontal)
+
+byte 3:
+
+ bit 7 6 5 4 3 2 1 0
+ id2 id1 id0 1 0 0 0 1
+
+ id2..id0 = finger id
+
+byte 4:
+
+ bit 7 6 5 4 3 2 1 0
+ p3 p1 p2 p0 y11 y10 y9 y8
+
+ p7..p0 = pressure
+
+byte 5:
+
+ bit 7 6 5 4 3 2 1 0
+ y7 y6 y5 y4 y3 y2 y1 y0
+
+ y11..y0 = absolute y value (vertical)
+
+7.2.3 Motion packet
+ ~~~~~~~~~~~~~
+
+byte 0:
+
+ bit 7 6 5 4 3 2 1 0
+ id2 id1 id0 w 0 1 R L
+
+ L, R = 1 when Left, Right mouse button pressed
+ id2..id0 = finger id
+ w = 1 when delta overflows (> 127 or < -128), in this case
+ firmware sends us (delta x / 5) and (delta y / 5)
+
+byte 1:
+
+ bit 7 6 5 4 3 2 1 0
+ x7 x6 x5 x4 x3 x2 x1 x0
+
+ x7..x0 = delta x (two's complement)
+
+byte 2:
+
+ bit 7 6 5 4 3 2 1 0
+ y7 y6 y5 y4 y3 y2 y1 y0
+
+ y7..y0 = delta y (two's complement)
+
+byte 3:
+
+ bit 7 6 5 4 3 2 1 0
+ id2 id1 id0 1 0 0 1 0
+
+ id2..id0 = finger id
+
+byte 4:
+
+ bit 7 6 5 4 3 2 1 0
+ x7 x6 x5 x4 x3 x2 x1 x0
+
+ x7..x0 = delta x (two's complement)
+
+byte 5:
+
+ bit 7 6 5 4 3 2 1 0
+ y7 y6 y5 y4 y3 y2 y1 y0
+
+ y7..y0 = delta y (two's complement)
+
+ byte 0 ~ 2 for one finger
+ byte 3 ~ 5 for another