New OMNIKEY CardMan 4040 driver - review request

[Daniel Roethlisberger]

I've written a driver for the OMNIKEY CardMan 4040 pccard smartcard
reader using the vendor's Linux driver as a reference.  My driver seems
to work for me.  However, since this is my first attempt at writing a
FreeBSD device driver, I guess I'm bound to have missed some issues.

I would be grateful if some more experienced driver hackers could take a
look at it and let me know about whatever can be improved in some way.
Especially I'd like comments about callout / locking interaction in this
driver.

Here is a diff against RELENG_6_1:

   http://dragon.roe.ch/~roe/cmx/cmx-6.1-20070124.diff.gz

There's no manual page yet, but other than that, the driver should be
complete.

-Dan

-- 
Daniel Roethlisberger <daniel at roe.ch>