Hi,

This diff: https://people.freebsd.org/~kevans/tn40xx-build.diff applied on top of what you have here should hook it up to the build properly-ish (sys/modules/Makefile should have a SUBDIR+= tn40xx line later, but needs testing first) -- you can add device tn40xx to your kernconf and get the driver built into the kernel, or walk into sys/modules/tn40xx and make the kmod manually.

You should also go ahead and remove the .depend.* files from the patch when you re-roll.

I'll look more closely at the code, but the first thing that stands out is that this driver lacks a basic man page.

This driver lacks a man page.