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diff --git a/Documentation/input/elantech.txt b/Documentation/input/elantech.txt new file mode 100644 index 00000000000..a10c3b6ba7c --- /dev/null +++ b/Documentation/input/elantech.txt @@ -0,0 +1,405 @@ +Elantech Touchpad Driver +======================== + + Copyright (C) 2007-2008 Arjan Opmeer <arjan@opmeer.net> + + Extra information for hardware version 1 found and + provided by Steve Havelka + + Version 2 (EeePC) hardware support based on patches + received from Woody at Xandros and forwarded to me + by user StewieGriffin at the eeeuser.com forum + + +Contents +~~~~~~~~ + + 1. Introduction + 2. Extra knobs + 3. Hardware version 1 + 3.1 Registers + 3.2 Native relative mode 4 byte packet format + 3.3 Native absolute mode 4 byte packet format + 4. Hardware version 2 + 4.1 Registers + 4.2 Native absolute mode 6 byte packet format + 4.2.1 One finger touch + 4.2.2 Two finger touch + + + +1. Introduction + ~~~~~~~~~~~~ + +Currently the Linux Elantech touchpad driver is aware of two different +hardware versions unimaginatively called version 1 and version 2. Version 1 +is found in "older" laptops and uses 4 bytes per packet. Version 2 seems to +be introduced with the EeePC and uses 6 bytes per packet. + +The driver tries to support both hardware versions and should be compatible +with the Xorg Synaptics touchpad driver and its graphical configuration +utilities. + +Additionally the operation of the touchpad can be altered by adjusting the +contents of some of its internal registers. These registers are represented +by the driver as sysfs entries under /sys/bus/serio/drivers/psmouse/serio? +that can be read from and written to. + +Currently only the registers for hardware version 1 are somewhat understood. +Hardware version 2 seems to use some of the same registers but it is not +known whether the bits in the registers represent the same thing or might +have changed their meaning. + +On top of that, some register settings have effect only when the touchpad is +in relative mode and not in absolute mode. As the Linux Elantech touchpad +driver always puts the hardware into absolute mode not all information +mentioned below can be used immediately. But because there is no freely +available Elantech documentation the information is provided here anyway for +completeness sake. + + +///////////////////////////////////////////////////////////////////////////// + + +2. Extra knobs + ~~~~~~~~~~~ + +Currently the Linux Elantech touchpad driver provides two extra knobs under +/sys/bus/serio/drivers/psmouse/serio? for the user. + +* debug + + Turn different levels of debugging ON or OFF. + + By echoing "0" to this file all debugging will be turned OFF. + + Currently a value of "1" will turn on some basic debugging and a value of + "2" will turn on packet debugging. For hardware version 1 the default is + OFF. For version 2 the default is "1". + + Turning packet debugging on will make the driver dump every packet + received to the syslog before processing it. Be warned that this can + generate quite a lot of data! + +* paritycheck + + Turns parity checking ON or OFF. + + By echoing "0" to this file parity checking will be turned OFF. Any + non-zero value will turn it ON. For hardware version 1 the default is ON. + For version 2 the default it is OFF. + + Hardware version 1 provides basic data integrity verification by + calculating a parity bit for the last 3 bytes of each packet. The driver + can check these bits and reject any packet that appears corrupted. Using + this knob you can bypass that check. + + It is not known yet whether hardware version 2 provides the same parity + bits. Hence checking is disabled by default. Currently even turning it on + will do nothing. + + +///////////////////////////////////////////////////////////////////////////// + + +3. Hardware version 1 + ================== + +3.1 Registers + ~~~~~~~~~ + +By echoing a hexadecimal value to a register it contents can be altered. + +For example: + + echo -n 0x16 > reg_10 + +* reg_10 + + bit 7 6 5 4 3 2 1 0 + B C T D L A S E + + E: 1 = enable smart edges unconditionally + S: 1 = enable smart edges only when dragging + A: 1 = absolute mode (needs 4 byte packets, see reg_11) + L: 1 = enable drag lock (see reg_22) + D: 1 = disable dynamic resolution + T: 1 = disable tapping + C: 1 = enable corner tap + B: 1 = swap left and right button + +* reg_11 + + bit 7 6 5 4 3 2 1 0 + 1 0 0 H V 1 F P + + P: 1 = enable parity checking for relative mode + F: 1 = enable native 4 byte packet mode + V: 1 = enable vertical scroll area + H: 1 = enable horizontal scroll area + +* reg_20 + + single finger width? + +* reg_21 + + scroll area width (small: 0x40 ... wide: 0xff) + +* reg_22 + + drag lock time out (short: 0x14 ... long: 0xfe; + 0xff = tap again to release) + +* reg_23 + + tap make timeout? + +* reg_24 + + tap release timeout? + +* reg_25 + + smart edge cursor speed (0x02 = slow, 0x03 = medium, 0x04 = fast) + +* reg_26 + + smart edge activation area width? + + +3.2 Native relative mode 4 byte packet format + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +byte 0: + bit 7 6 5 4 3 2 1 0 + c c p2 p1 1 M R L + + L, R, M = 1 when Left, Right, Middle mouse button pressed + some models have M as byte 3 odd parity bit + when parity checking is enabled (reg_11, P = 1): + p1..p2 = byte 1 and 2 odd parity bit + c = 1 when corner tap detected + +byte 1: + bit 7 6 5 4 3 2 1 0 + dx7 dx6 dx5 dx4 dx3 dx2 dx1 dx0 + + dx7..dx0 = x movement; positive = right, negative = left + byte 1 = 0xf0 when corner tap detected + +byte 2: + bit 7 6 5 4 3 2 1 0 + dy7 dy6 dy5 dy4 dy3 dy2 dy1 dy0 + + dy7..dy0 = y movement; positive = up, negative = down + +byte 3: + parity checking enabled (reg_11, P = 1): + + bit 7 6 5 4 3 2 1 0 + w h n1 n0 ds3 ds2 ds1 ds0 + + normally: + ds3..ds0 = scroll wheel amount and direction + positive = down or left + negative = up or right + when corner tap detected: + ds0 = 1 when top right corner tapped + ds1 = 1 when bottom right corner tapped + ds2 = 1 when bottom left corner tapped + ds3 = 1 when top left corner tapped + n1..n0 = number of fingers on touchpad + only models with firmware 2.x report this, models with + firmware 1.x seem to map one, two and three finger taps + directly to L, M and R mouse buttons + h = 1 when horizontal scroll action + w = 1 when wide finger touch? + + otherwise (reg_11, P = 0): + + bit 7 6 5 4 3 2 1 0 + ds7 ds6 ds5 ds4 ds3 ds2 ds1 ds0 + + ds7..ds0 = vertical scroll amount and direction + negative = up + positive = down + + +3.3 Native absolute mode 4 byte packet format + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +byte 0: + firmware version 1.x: + + bit 7 6 5 4 3 2 1 0 + D U p1 p2 1 p3 R L + + L, R = 1 when Left, Right mouse button pressed + p1..p3 = byte 1..3 odd parity bit + D, U = 1 when rocker switch pressed Up, Down + + firmware version 2.x: + + bit 7 6 5 4 3 2 1 0 + n1 n0 p2 p1 1 p3 R L + + L, R = 1 when Left, Right mouse button pressed + p1..p3 = byte 1..3 odd parity bit + n1..n0 = number of fingers on touchpad + +byte 1: + firmware version 1.x: + + bit 7 6 5 4 3 2 1 0 + f 0 th tw x9 x8 y9 y8 + + tw = 1 when two finger touch + th = 1 when three finger touch + f = 1 when finger touch + + firmware version 2.x: + + bit 7 6 5 4 3 2 1 0 + . . . . x9 x8 y9 y8 + +byte 2: + bit 7 6 5 4 3 2 1 0 + x7 x6 x5 x4 x3 x2 x1 x0 + + x9..x0 = absolute x value (horizontal) + +byte 3: + bit 7 6 5 4 3 2 1 0 + y7 y6 y5 y4 y3 y2 y1 y0 + + y9..y0 = absolute y value (vertical) + + +///////////////////////////////////////////////////////////////////////////// + + +4. Hardware version 2 + ================== + + +4.1 Registers + ~~~~~~~~~ + +By echoing a hexadecimal value to a register it contents can be altered. + +For example: + + echo -n 0x56 > reg_10 + +* reg_10 + + bit 7 6 5 4 3 2 1 0 + 0 1 0 1 0 1 D 0 + + D: 1 = enable drag and drop + +* reg_11 + + bit 7 6 5 4 3 2 1 0 + 1 0 0 0 S 0 1 0 + + S: 1 = enable vertical scroll + +* reg_21 + + unknown (0x00) + +* reg_22 + + drag and drop release time out (short: 0x70 ... long 0x7e; + 0x7f = never i.e. tap again to release) + + +4.2 Native absolute mode 6 byte packet format + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +4.2.1 One finger touch + ~~~~~~~~~~~~~~~~ + +byte 0: + + bit 7 6 5 4 3 2 1 0 + n1 n0 . . . . R L + + L, R = 1 when Left, Right mouse button pressed + n1..n0 = numbers of fingers on touchpad + +byte 1: + + bit 7 6 5 4 3 2 1 0 + x15 x14 x13 x12 x11 x10 x9 x8 + +byte 2: + + bit 7 6 5 4 3 2 1 0 + x7 x6 x5 x4 x4 x2 x1 x0 + + x15..x0 = absolute x value (horizontal) + +byte 3: + + bit 7 6 5 4 3 2 1 0 + . . . . . . . . + +byte 4: + + bit 7 6 5 4 3 2 1 0 + y15 y14 y13 y12 y11 y10 y8 y8 + +byte 5: + + bit 7 6 5 4 3 2 1 0 + y7 y6 y5 y4 y3 y2 y1 y0 + + y15..y0 = absolute y value (vertical) + + +4.2.2 Two finger touch + ~~~~~~~~~~~~~~~~ + +byte 0: + + bit 7 6 5 4 3 2 1 0 + n1 n0 ay8 ax8 . . R L + + L, R = 1 when Left, Right mouse button pressed + n1..n0 = numbers of fingers on touchpad + +byte 1: + + bit 7 6 5 4 3 2 1 0 + ax7 ax6 ax5 ax4 ax3 ax2 ax1 ax0 + + ax8..ax0 = first finger absolute x value + +byte 2: + + bit 7 6 5 4 3 2 1 0 + ay7 ay6 ay5 ay4 ay3 ay2 ay1 ay0 + + ay8..ay0 = first finger absolute y value + +byte 3: + + bit 7 6 5 4 3 2 1 0 + . . by8 bx8 . . . . + +byte 4: + + bit 7 6 5 4 3 2 1 0 + bx7 bx6 bx5 bx4 bx3 bx2 bx1 bx0 + + bx8..bx0 = second finger absolute x value + +byte 5: + + bit 7 6 5 4 3 2 1 0 + by7 by8 by5 by4 by3 by2 by1 by0 + + by8..by0 = second finger absolute y value |