TODOs prior to this driver moving out of staging
------------------------------------------------
1. Implement retries for RCODE_BUSY, RCODE_NO_ACK and RCODE_SEND_ERROR
   - I/O is handled asynchronously which presents some issues when error
     conditions occur.
2. Implement _robust_ console on top of this. The existing prototype console
   driver is not ready for the big leagues yet.
3. Expose means of controlling attach/detach of peers via sysfs. Include
   GUID-to-port matching/whitelist/blacklist.

-- Issues with firewire stack --
1. This driver uses the same unregistered vendor id that the firewire core does
     (0xd00d1e). Perhaps this could be exposed as a define in
     firewire.h?
3. Maybe device_max_receive() and link_speed_to_max_payload() should be
     taken up by the firewire core?

-- Issues with TTY core --
  1. Hack for alternate device name scheme
     - because udev no longer allows device renaming, devices should have
       their proper names on creation. This is an issue for creating the
       fwloop<n> device with the fwtty<n> devices because although duplicating
       roughly the same operations as tty_port_register_device() isn't difficult,
       access to the tty_class & tty_fops is restricted in scope.

       This is currently being worked around in create_loop_device() by
       extracting the tty_class ptr and tty_fops ptr from the previously created
       tty devices. Perhaps an add'l api can be added -- eg.,
       tty_{port_}register_named_device().