"cell-index" vs. "index" vs. no index in I2C device nodes

[David Gibson]

On Thu, Jun 05, 2008 at 06:52:25AM -0500, Josh Boyer wrote:
> On Thu, 5 Jun 2008 10:45:42 +0200
> Stefan Roese <sr at denx.de> wrote:
> 
> > On Thursday 05 June 2008, Jean Delvare wrote:
> > > > > Maybe it is time to remove the index, or maybe we should go back to
> > > > > using both a static and the index. But at the time we decided to
> > > > > enforce an index.
> > > >
> > > > So what should we do now? Currently I2C doesn't work at all on 4xx since
> > > > the driver expects the "index" property and no dts sets this property.
> > > > Personally I would like to move to using cell-index here, since this
> > > > seems to be more common. But I could also life with removing the index
> > > > property and using the "static index" if this is preferred and/or
> > > > acceptable.
> > > >
> > > > Please advise. Thanks.
> > >
> > > As far as I am concerned, it's really up to the maintainers and users
> > > of this platform. All I am asking for is that you do not call
> > > i2c_add_numbered_adapter() on an adapter with an automatically
> > > generated number. This function must only be used for adapter's those
> > > number is well defined. If an adapter doesn't have a well-defined
> > > number then use i2c_add_adapter() (but then you can no longer declare
> > > your I2C devices as part of the platform data.)
> > 
> > Full ack from me. So I suggest to use "cell-index" if available and otherwise 
> > use an incremented number, same as the FSL i2c driver does now:
> > 
> > http://ozlabs.org/pipermail/linuxppc-dev/2008-June/057254.html
> > 
> > If nobody objects I'll send a patch to add the cell-index to all 4xx dts files 
> > in a short while.
> 
> I have no large objections.  Though as Scott pointed out, this isn't
> really a proper use of "cell-index".  Something like:
> 
> "linux,i2c-index"
> 
> seems to be a more distinct definition of what this is.  But I have no
> idea how well that would go over, and it would probably need to be
> changed in all the fsl boards as well.

Don't do that.  Use aliases, that's what they're for.

-- 
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_!
http://www.ozlabs.org/~dgibson