Solved evdev under FreeBSD 11

Tried that, I've patched it into my 11.0-RC3 kernel and it applied cleanly (I guess we haven't diverged much yet). Everything boots alright but I was expecting to see something in /dev/input though, so far nothing. Maybe it's just not going to work on 11.0-RC3
I'm not sure I follow you, you have MFC'ed r305706 to 11-RC3? I remember using a previous evdev patch on my rpi, it was on 11 and it worked just fine.
Yeah, if I apply that patch as well, I see a device node under /dev/input when attaching a USB mouse. My keyboard (atkbd0) and touchpad (psm0) don't seem to do anything though. Understand it's early days - it's interesting to play with this stuff though.