I was not able to get the touchpad working using any of the typical solutions. What I found was disabling i2c_hid fixed the issue, but doing the actual disabling didn’t work. Adding an option in /etc/modprobe.d/blacklist.conf did not work. The real trick for this system was to add a kernel boot line in /etc/default/grub like so:
Add that do the this line as one of the option (there are probably several options in there for Centos7):
modprobe.blacklist=i2c_hid rhgb quiet"
Then , because this is EFI system you need to update grub using this:
grub2-mkconfig -o /boot/efi/EFI/centos/grub.cfg
Then after a reboot the touchpad finally worked in Gnome.
PS. I found out that disabling actually works because I could run “rmmod i2c_hid” and it was removed from the “lsmod” listing. Immediately the touchpad started working. I also had one of the grub options set, which did not seem to make any difference: i8042.nopnp.