The role of the FCP device driver is to pass information between the operating system and the FCP adapter device driver by accepting I/O requests and passing these requests to the FCP adapter device driver. The device driver should accept either character or block I/O requests, build the necessary FCP commands, and then issue these commands to the device through the FCP adapter device driver.
The FCP device driver should also process the various required reservations and releases needed for the device. The device driver is notified through the iodone kernel service once the adapter has completed the processing of the command. The device driver should then notify its calling process that the request has completed processing through the iodone kernel service.
The FCP Adapter Device Driver Overview discusses overview information about the adapter device driver. Specific information about interfaces to the adapter driver and the device driver is available in FCP Adapter/Device Interface.