[PATCH 04/14] bus: mvebu-mbus: Add static window allocation to the DT binding

Ezequiel Garcia
2013-06-12T21:12:22Z

On Wed, Jun 12, 2013 at 10:45:55PM +0200, Arnd Bergmann wrote:
> On Wednesday 12 June 2013, Grant Likely wrote:
> > I think we should have almost everything needed already to do this.
> > of_bus allows arbitrary mapping code to be used at any stage in the
> > translation. We might need to add some glue so that of_busses[] can
> > be assembled by the linker to allow an mbus of_bus stanza to live
> > outside of drivers/of/address.c
> >
>
> Actually, the best thing about this solution is that we don't even
> have to bother setting up the mappings when loading the mbus driver:
> We don't need any ranges (other than internal-regs) in DT, and we
> don't need complex logic to search through the child devices to
> figure out what the mappings should be. The only thing one needs
> to do here is check if a mapping already exists when we get into the
> of_bus handler and create one for the device being translated if
> there isn't one!
>

This departs considerably from what I'm aiming right now.

Are you suggesting to not put *any* mapping in the mbus 'ranges' node in
the DT (other than internal-regs)?

In that case, can you explain a bit further how the mbus would
decide a base address for each window? I guess you're thinking
in a first-fit algorithm, right?

--
Ezequiel Garc?a, Free Electrons
Embedded Linux, Kernel and Android Engineering