Thinkpad Trackpoint (IBM/Lenovo)

Enable middle click scrolling with trackpoint (works both for horizontal and vertical scrolling).

Listing 1: /etc/X11/xorg.conf.d/50-trackpoint.conf

Section "InputClass"
    Identifier      "Trackpoint Wheel Emulation"
    MatchProduct    "TPPS/2 IBM TrackPoint|DualPoint Stick|Synaptics Inc. Composite TouchPad / TrackPoint|ThinkPad USB Keyboard with TrackPoint|USB Trackpoint pointing device|Composite TouchPad / TrackPoint"
    MatchDevicePath "/dev/input/event*"
    Option          "EmulateWheel"       "true"
    Option          "EmulateWheelButton" "2"
    Option          "Emulate3Buttons"    "false"
    Option          "XAxisMapping"       "6 7"
    Option          "YAxisMapping"       "4 5"
EndSection