🚀 go-pugleaf

I am considering making a Widget that would interface to the SCSI bus.
This device would do block mode transfers (like a disk) when accessed
thru one device address, and character like transfers when accessed 
at a different device address. Although designing  the hardware
play on the SCSI bus seems very straightforward, getting a user written
program to access this device thru a standard SCSI port is not
so straightforward.  My user program should be able to:

           dma_read(staring_block,buffer_address,byte_count,&stat)
           dma_write(staring_block,buffer_address,byte_count,&stat)
           char_read(buffer_address,byte_count,&stat)
           char_write(buffer_address,byte_count,&stat)

In addition, each call should be able to set up a function address, so
that the specified function could be called when the operation is
finished.

Is this functionality available without writing a device driver?