Hey Guys,
apparently the hdaps driver isnt loaded correctly on bootup, as there is no interface in sysfs and no output in dmesg. If I load the module directly via "sudo make load HDAPS=1" it works fine. I installed the driver via "sudo make install HDAPS=1", as the readme stated.
My Device is a Lenovo Thinkpad x220T, running the latest Ubuntu 18.10 minimal with i3wm