[PATCH 05/14] at91: use structure to store the current soc

[plagnioj@jcrosoft.com (Jean-Christophe PLAGNIOL-VILLARD)]

On 00:16 Tue 03 May     , Russell King - ARM Linux wrote:
> On Tue, May 03, 2011 at 09:27:12AM +1200, Ryan Mallon wrote:
> > Russell, what is your opinion on this? Should we use individual
> > mach-types for the above boards and have them explicitly specify their
> > cpu/soc type, or should we be aiming to have a single mach-type for all
> > of them and determine the cpu/soc type in code?
> 
> I don't like answering these questions because it requires understanding
> the differences between the various individual SoCs to determine what's
> possible.
> 
> You are correct that CPU type is determined at run-time by the kernel,
> and whether its an 920T or 926T CPU is neither here or there to the
> kernel.  It's really the SoC type that's the problem, and we don't have
> a very good way of specifying that (partly as there is no standard way
> to tell what sort of SoC we have.)
> 
> So, really, it's a platform specific question.  If there is some way
> that the SoC type can be detected from the hardware, that may be an
> appropriate way to deal with that issue.  If not, then the mach-type
> approach (which I assume is what AT91 currently does) is probably as
> good as any other until we have something like DT.
Except we have Russell it's we need to read 2 registers differents

which is 0x0 if does not containt a cpu id
or or the cpu id of the current chip

So I do not see the big deal

Best Regards,
J.