On Tue, Apr 28, 2020 at 03:49:49PM +0100, Robin Murphy wrote:

> For better or worse, the platform bus is the dumping ground for random crap,
> so we just have to deal with all the abstraction breakage that leaks out of
> that.

The reason we're using the platform bus for this is that historically
people were creating buses which were essentially carbon copies of the
platform bus with the name changed and it was felt that rather than
duplicate code it was better to just use platform devices with no MMIO
ranges defined.  If there's some assumptions about DMA for platform
devices floating about somewhere it might be reasonable to revisit this
and create a non-DMA variant of platform devices since there is a
meaningful difference.