Re: powerpc_flash_init(), wtf!?
From: Sergei Shtylyov <hidden>
Date: 2007-05-05 17:35:03
Hello. David Gibson wrote:
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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? :-]
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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?).
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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.
Erm, how multiple memory ranges are supposed to work? Aren't the addresses
in the "reg" property of subnodes relative to the "ranges" property?
WBR, Sergei