Re: powerpc_flash_init(), wtf!?

David Gibson
2007-05-03T23:56:20Z

On Thu, May 03, 2007 at 08:07:27PM +0200, Segher Boessenkool wrote:
> >> Yeah, you're right here, and I've probably misunderstood what
> >> "memory" node was. In fact, the flash in my system resides on the
> >> same local bus as RAM, so the proper place would be behind the "lbc"
> >> (or whatever -- it doesn't exist as yet) node on the "soc" bus. Do
> >> you think I need to go and document it as well for such cause? :-]
> >
> > No, that probably won't do. MPC85xx SoC bus has ranges = <e0000000
> > 00100000> and the NOR flash is mapped at 0xff000000, so it seems that
> > it can't be located under the "soc" bus (unless that latter has
> > "ranges" prop extended?).
>
> If the RAM and/or ROM sit on the SoC bus, the "ranges"
> property in the SoC node should be able to translate
> their addresses, yes. You could opt for having the
> memory controller a separate device node, as a sibling
> of the "soc" node, if that agrees better with your
> SoC architecture. "It all depends".

But if the flash really is on an external bus controlled by a bus
controller on the SoC, it sounds like it should go under that bus
bridge. In which case the SoC would need another range in its ranges
property.

--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!