Re: [PATCH] powerpc: add of_find_next_property andof_get_aliased_index

[Josh Boyer <jwboyer@linux.vnet.ibm.com>]

On Thu, 26 Jun 2008 20:41:12 +0200
Stefan Roese <sr@denx.de> wrote:

> On Thursday 26 June 2008, Sean MacLennan wrote:
> > > Well, there's a lot of disagreement on this subject.  Not only do we
> > > not agree on a method of enumerating devices, a lot of people have a
> > > problem with the concept of enumerating them in the first place!
> >
> > An interesting point is that I enforced an index in the i2c-ibm_iic
> > driver with no disagreement at all ;)
> 
> You have been lucky I suppose. :)
> 
> I could easily just have used this existing "index" property for the other 4xx 
> boards, but expected NAK's for this. That and because FSL uses "cell-index" 
> is why I asked prior to sending patches.
> 
> Now I have no idea how to support I2C on the other 4xx boards. Perhaps Josh 
> could advise how this should be done?

As David said elsewhere, cell-index is fine for figuring out how to
access the CPM registers, etc.  But it's not good for enumerating
across the whole system.

For I2C specifically, I think Sean already has a patch to switch the
4xx driver to not use the numbered functions, which eliminates the need
for the enumeration all together.  That seems like the right approach
to me.

josh