Input Devices

This page is for covering alternate input devices, like touch screens and tablets.

-- JimMcQuillan - 08 Mar 2005

Wacom Tablets

Wacom support is included as a module in the LTSP kernel. Here is how to get a USB Wacom tablet working with LTSP's 2.6.9 kernel and Xorg.

In order to activate it you need to modify your lts.conf file, normally located at /opt/ltsp[version]/i386/etc/lts.conf.

Add the following lines:

        HOTPLUG            = Y
        MODULE_01          = uhci-hcd
        MODULE_02          = usbhid
        MODULE_03          = wacom
        X_MOUSE_PROTOCOL   = "imps/2"
        X_MOUSE_DEVICE     = "/dev/input/mouse0"
        X4_MODULE_01       = wacom

Of course you might have other modules in your lts.conf file so adjust accordingly. My file includes lines for a USB mouse, note that if you intend to use a USB Wacom tablet with a USB mouse don't set the mouse for /dev/input/mice or it will conflict with the Wacom mouse.

Next, /opt/ltsp/i386/etc/build_x4_cfg needs some modifications.

Add the wacom specific input devices in the server layout:Section

"ServerLayout"
        Identifier "XFree86 Configured"
        Screen      0   "Screen0" 0 0
        InputDevice     "Keyboard0" "CoreKeyboard"
        InputDevice     "Mouse0" "CorePointer"
        InputDevice     "Mouse1" "AlwaysCore"
        InputDevice     "cursor" "SendCoreEvents"
        InputDevice     "stylus" "SendCoreEvents"
        InputDevice     "eraser" "SendCoreEvents"

Modify the mouse input device section:

Section "InputDevice"
       Identifier  "Mouse1"
       Driver      "mouse"
       Option      "Device" "${X_USBMOUSE_DEVICE:-"/dev/input/mouse0"}"
       Option      "Protocol"        "${X_USBMOUSE_PROTOCOL:-"PS/2"}"
       Option      "BaudRate"        "${X_USBMOUSE_BAUD}"
       Option      "Resolution"      "${X_USBMOUSE_RESOLUTION}"
       Option      "Emulate3Buttons" "${USBEMULATE_3_BUTTONS:-"off"}"
       Option      "ZAxisMapping"    "4 5"
       Option      "Buttons"         "${X_USBMOUSE_BUTTONS:-"3"}"
EndSection

Again, make sure to change from "/dev/input/mice" to "/dev/input/mouse0" for the same reasons as stated above.

Finally--Add the wacom input devices to build_x4_cfg right after Mouse1:

Section "InputDevice"
        Driver      "wacom"
        Identifier  "cursor"
        Option      "Device" "/dev/input/event2"
        Option      "Type" "cursor"
        Option      "Mode" "relative"
        Option      "Suppress" "2"
        Option      "USB" "on"
        Option      "ZAxisMapping"    "5 4"
EndSection

Section "InputDevice"
        Driver      "wacom"
        Identifier  "stylus"
        Option      "Device" "/dev/input/event2"
        Option      "Type" "stylus"
        Option      "Mode" "absolute"
        Option      "USB" "on"
        Option      "Tilt" "on"
        Option      "Threshold" "20"
        Option      "HistorySize" "200"
EndSection

Section "InputDevice"
        Driver      "wacom"
        Identifier  "eraser"
        Option      "Device" "/dev/input/event2"
        Option      "Type" "eraser"
        Option      "Mode" "absolute"
        Option      "USB" "on"
        Option      "Tilt" "on"
        Option      "Threshold" "20"
        Option      "HistorySize" "200"
EndSection

Note that my configuration uses /dev/input/event2 for the Wacom tablet. That may not be the case on your system. To find out, open a console on the client and cat /dev/input/event[x] and draw on the tablet to see if that's where it is seeing the tablet.

Hint: put this in your lts.conf and you can switch to a console with a Control + Alt + F2.

 SCREEN_01          = startx
 SCREEN_02          = shell

I've got a client that will switch from event2 to event1 or event0 depending if the system was booted up with the tablet plugged in or plugged in after boot up and which USB port is used.

This worked great until I got a brand new Wacom Intuos3 tablet. Intuos3 support wasn't added to the kernel until 2.6.12. I was able to build a 2.6.12 kernel in LBE, but it doesn't have supermount and may be pushing the envelope a bit too far. However, it was rather easy to get some new components from the the linux-wacom project, http://linuxwacom.sourceforge.net/ and make a patch that works for the LTSP 2.6.9 kernel. You can do it yourself in LBE or if you just want to get your tablet working simply get the Wacom-kit I included here and copy the modules in there proper location.

There is still some more work to be done. I'd like the X configuration to skip the Wacom sections is there is no tablet attached and to make a wacom link in /dev/input. This will be much easier once LTSP switches over from devfs to udev.

One more thing--Intuos3 has a "pad" feature that can be added to the X configuration but I haven't figured that one out yet.

Clearly this tip can use some improvement so please, feel free to edit this.

-- DanielFort - 29 Aug 2005

If you want to try building a 2.6.12 kernel in LBE, posted is the kernel-src that worked for me. Note that I took out the 2.4 kernel and supermount but I did apply the 2.6.12.5 kernel patch. Simply replace the kernel-src directory with this one and it should work.

-- DanielFort - 22 Sep 2005