Adding touchpad support to KDE
 

When I select system setting in KDE, then to input devices, there is nothing listed for touchpad. How can I add it so that I can tap to click and use vertical scrolling?

You need the kde-config-touchpad/synaptiks software.

Not sure on which it's called in Slack, should be the kde-config if you're running current since they changed the name quite some time ago.

Then rmmod psmouse and modprobe psmouse, or just reboot.

If your computer is using a synaptics touchpad (there are other companies who also make touchpads, so might want to check lspci to be sure), you can edit:

/usr/share/X11/xorg.conf.d/50-synaptics.conf

Look on Google and other resources to find the options desirable for what you want your touchpad to do. Good luck!

Thanks for answers, but still incomplete
 

I checked lspci and got a short list of items, but nothing about a trackpad. The computer is a Lenovo Thinkpad E520. Don't know if that will help identify it.

I ran a search on sbo for kde-config-touchpad, kde-config, and synaptiks. Nothing comes up. Synaptics pulls up two items, but the only item of the two that makes sense is kcm_touchpad. Don't suppose you could clue me in a bit better?

Edit: The file I mentioned works just fine. I spent some more time learning about it today.