[PATCH v2 0/5] Convert m68k MVME147 WD33C93 SCSI driver to DMA API

[Michael Schmitz <schmitzmic@gmail.com>]

This series was precipitated by Arnd removing CONFIG_VIRT_TO_BUS. The
m68k WD33C93 still used virt_to_bus to convert virtual addresses to
physical addresses suitable for the DMA engines (note m68k does not
have an IOMMU and uses a direct mapping for DMA addresses). 

Arnd suggested to use dma_map_single() to set up dma mappings instead
of open-coding much the same in every driver dma_setup() function. An
earlier patch series has converted the three Amiga WD33C93 drivers,
this series now takes care of the sole remaining m68k WD33C93 driver.

The m68k VME mvme147 driver has no DMA addressing or alignment
restrictions and can be converted in the same way as the Amiga a3000
one in my previous series, but requires conversion to a platform
device driver first.

Changes from v1: 
- use of devm_platform_ioremap_resource() to convert phys. resource
to virtual address for chip registers.

Only compile tested so far, and hardware testing might be hard to do.
I'd appreciate someone giving this a thorough review.

Cheers,

   Michael