As far as I now you don't need drivers, on Linux.
You just hook up your keyboard to your pc. Then you start LMMS, and go to the midi tab of an instrument.
You should be able to select your piano there.
Click on the small piano keyboard icon, then you see a list and your Yamaha keyboard should be there.
Does this help ?
https://www.youtube.com/watch?v=p42P4d5 ... Occhipinti