int mpt_register (MPT_CALLBACK cbfunc, MPT_DRIVER_CLASS dclass);
This routine is called by a protocol-specific driver (SCSI host, LAN, SCSI target) to register it's reply callback routine. Each protocol-specific driver must do this before it will be able to use any IOC resources, such as obtaining request frames.
The SCSI protocol driver currently calls this routine thrice in order to register separate callbacks; one for ``normal'' SCSI IO; one for MptScsiTaskMgmt requests; one for Scan/DV requests.
Returns a positive integer valued ``handle'' in the range (and S.O.D. order) {N,...,7,6,5,...,1} if successful. Any non-positive return value (including zero!) should be considered an error by the caller.