.TH TOUCHPAD-EDGE-DETECTOR "1"
.SH NAME
touchpad-edge-detector \- print the axis ranges for a touchpad device
.SH SYNOPSIS
.B touchpad-edge-detector [--help] \fIWxH /dev/input/eventX\fR
.SH DESCRIPTION
.PP
The
.B touchpad-edge-detector
tool reads touchpad events from the kernel and records the minimum and
maximum coordinates based on user input. This is an interactive tool, the
user must move a finger around the touchpad, attempting to trigger an
event at all edges of the touchpad.
.PP
To terminate the event collection and print a summary, press Ctrl+C. It is
recommended that the tool is run several times to guarantee a reliable
result.
.SH OPTIONS
.TP 8
.I WxH
The width and height of the touchpad in mm. For a touchpad 100mm wide and
75mm high, the argument is thus \fI100x75\fR. This is a required argument.
.TP 8
.I /dev/input/eventX
The event node of the touchpad to read events from. A list of possible event
nodes can be obtained with either one of the following commands: \fBlibinput
record\fR, \fBevemu-record\fR, or \fBevtest\fR. Alternatively the event node
for a device is listed in the \fBHandlers=\fR line \fI/proc/bus/input/devices\fR.
This is a required argument.
.TP 8
.B --help
Print a short help description
.SH NOTES
.PP
On completion, this tool prints a summary of the collected events and a
suggested udev rule. Due to rounding errors it is rare to get an exact match
for the touchpad's dimensions, but any discrepancy of more than 5mm should
be corrected with the suggested udev rule.
.PP
The udev rule should be simplified and submitted as a pull request to the
system repository at \fIhttps://github.com/systemd/systemd\fR. For further
guidance, see the file \fI/usr/lib/udev/hwdb.d/60-evdev.hwdb\fR.
.SH SEE ALSO
udev(7)