For what it's worth, for the DEC FDDI adapters I choose a somehwat
different approach.

The bus independent files live at:

	dev/ic/pdq.c			hardware specific code
	dev/ic/pdq_ifsubr.c		BSD specific code (bus independent)

And then for each bus type, there's a different file which contains the
probe (aka match) and attach routines:

	dev/pci/if_fpa.c		PCI DEFPA probe/attach
	dev/eisa/if_fea.c		EISA DEFEA probe/attach
	dev/tc/if_fta.c			TC DEFTA probe/attach

if_fpa.c already exists, if_fea.c is almost done, if_fta.c is still under
contruction.

Eventually there could even be:

	dev/uba/if_fqa.c		Qbus DEFQA probe/attach
	dev/fbus/if_faa.c		Futurebus+ DEFAA probe/attach

if I ever really inspired and the either the VAX or PMAX ports adopt
the new bus code or the ALPHA port support the FB+ DEC 4000s.

However, unlike if_ed* each of these driver present a different name
to the user.  Also, each one has a separate cfdriver.  I prefer this since
it is very obvious that fpa0 is the DEFPA and fea0 is the DEFEA when
you have a system with multiple bus types (like the AlphaStation 600).
-- 
Matt Thomas               Internet:   matt@3am-software.com
3am Software Foundry      WWW URL:    http://www.3am-software.com/bio/matt.html
Westford, MA              Disclaimer: I disavow all knowledge of this message