Add a device configuration about trackpoint in X.org.
Step:
1. Create a directory under /etc/X11
>> mkdir /etc/X11/xorg.conf.d
2. Create configuration
>> touch /etc/X11/xorg.conf.d/20-thinkpad.conf
3. Add description for Trackpoint device
/etc/X11/xorg.conf.d/20-thinkpad.conf
Section "InputClass"
Identifier "Trackpoint Wheel Emulation"
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"
MatchDevicePath "/dev/input/event*"
Option "EmulateWheel" "true"
Option "EmulateWheelButton" "2"
Option "Emulate3Buttons" "false"
Option "XAxisMapping" "6 7"
Option "YAxisMapping" "4 5"
EndSection
Reference: