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

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

On Thu, 5 Jun 2008 10:45:42 +0200
Stefan Roese <sr@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.

josh