sudo touchpad-edge-detector /dev/input/event6  
Touchpad ETPS/2 Elantech Touchpad on /dev/input/event6
Move one finger around the touchpad to detect the actual edges
Kernel says:	x [0..2204], y [0..1160]
Touchpad sends:	x [19..2197], y [12..1144] \^C

Touchpad size as listed by the kernel: 71x37mm
Calculate resolution as:
	x axis: 2204/<width in mm>
	y axis: 1160/<height in mm>

Suggested udev rule:
# <Laptop model description goes here>
evdev:name:ETPS/2 Elantech Touchpad:dmi:bvnLENOVO:bvrG3ETA5WW(2.65):bd10/20/2015:svnLENOVO:pn2464A26:pvrThinkPadL430:rvnLENOVO:rn2464A26:rvrNotDefined:cvnLENOVO:ct10:cvrNotAvailable:*
 EVDEV_ABS_00=19:2197:<x resolution>
 EVDEV_ABS_01=12:1144:<y resolution>
 EVDEV_ABS_35=19:2197:<x resolution>
 EVDEV_ABS_36=12:1144:<y resolution>