Writing drivers that will work with FreeBSD

[jekillen]

Hello;
Is there a one stop location where I can get info on writing
device drivers that will work with FreeBSD (v6+)? There is
a book out called Linux Device Drivers (perhaps I shouldn't
mention the publisher). I would be mostly a beginner
and presume that some assembler knowledge would be needed.
Is there an 'API' type of approach to this?
I'm trying to estimate the feasibility of writing a driver for a
MIDI interface (I don't know which yet, it would depend on
how much data a particular manufacture makes available
about a particular device).
Thanks in advance
JK