Touchpad not working on Gnome 17.04 (it worked on Unity 17.04)

Question

I just did a clean reinstall of Ubuntu to migrate from Unity to Gnome.

However, a lot of drivers that were present in 17.04 are missing in Gnome 17.04

less /proc/bus/input/devices

Doesn't show my touchpad.

I am using Dell 7559.

How do I properly fix everything?

(There's also other stuff missing, such as function keys not working, no display brightness controls, but I suppose I should create new threads for those? Everything was working properly and out of the box on 16.04 -> 16.10 and 17.04, except for GPU drivers. Sorry for this clutter, I am new here.)

Solution

After following this answer to get my function keys working, my touchpad is fine again.