As previously discussed on this list, I would like to see support for
multiple bus instances implemented differently. Rather than storing
the spi_master instances in an array in the pci device private data,
the pci device should register a separate platform_device for each spi
bus instance, and each of those bus instances should get bound to a
topcliff_spi_bus driver which doesn't need to have any special
knowledge about how many spi_master instances actually exist.
Basically, the way it is implemented in this patch isn't taking
advantage of the infrastructure and instance management provided by
the driver model.