[PATCH 2/6] PowerPC 440EPx: Sequoia DTS
Segher Boessenkool
segher at kernel.crashing.org
Tue Aug 7 07:03:41 EST 2007
>> "bit-swizzling" or something which can be defined to describe some odd
>> connections. If absent we'd default to direct mapping. Segher, is
>> that idea going to cause you to scream?
>
> Actually, checking for the presence of all possible perverted
> mapping
> props doesn't seem a good idea -- it's simpler to check for the
> presence of
> one prop (like "direct-mapped" I was thinking about, or maybe
> "simple-map").
There shouldn't be many "perverted" properties -- really weird
mappings can just do a special "compatible" value, the standard
kernel driver can't handle them either, anyway.
A few extra property lookups are dirt cheap. This isn't
speed-critical code anyway.
>> Well, now you do. I believe USB usually uses that format, too.
>
> USB what, hosts or devices?
The unit-address of a device is specified in its parent's
address space. USB hosts don't typically have a USB bus as
parent ;-) (but they can still have a comma in the unit
address. Confused? Don't be :-) ).
> Hm, right... the option here would be to always have at least one
> partition and no "reg" property in the MTD node itself... or have
> "reg" with
> no partition and "ranges" if partitions are there... :-)
No way. "reg" is needed *no matter what* -- I'll not list the
other problems with that proposal.
Segher
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