Comment 307 for bug 1372609

I can tell you that it did not work without ppa. You can test it by uninstalling focaltech-dkms.
And xinput will show Focaltech in mouse emulation mode.

From kernel 4.0 this driver is in mainine kernel. I made this ppa to backport it for current Ubuntu users.
In Ubuntu 15.10 it will work out of the box.