| Elantech Touchpad Driver |
| ======================== |
| |
| Copyright (C) 2007-2008 Arjan Opmeer <[email protected]> |
| |
| 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 |
| . . . . . x10 x9 x8 |
| |
| byte 2: |
| |
| bit 7 6 5 4 3 2 1 0 |
| x7 x6 x5 x4 x4 x2 x1 x0 |
| |
| x10..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 |
| . . . . . . y9 y8 |
| |
| byte 5: |
| |
| bit 7 6 5 4 3 2 1 0 |
| y7 y6 y5 y4 y3 y2 y1 y0 |
| |
| y9..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 |
