I2C eeprom compatibles? (was Re: [PATCH/RFC 03/19] ARM: shmobile: gose: add i2c2 bus to device tree)

[Simon Horman]

On Fri, Dec 18, 2015 at 11:32:15AM +0100, Wolfram Sang wrote:
> On Fri, Dec 18, 2015 at 10:06:48AM +0100, Arnd Bergmann wrote:
> > On Friday 18 December 2015 08:35:32 Wolfram Sang wrote:
> > > > 
> > > > It seems to me that we have some consensus around:
> > > > 
> > > >       compatible = "renesas,r1ex24002", "24c02";
> > > 
> > > Thinking again, "generic,24c02" or "generic-24c02" could also be an
> > > option.
> > > 
> > > > Should this be added to Documentation/devicetree/bindings/eeprom/eeprom.txt ?
> > > > Or documented elsewhere?
> > > 
> > > Probably we need a DT maintainers advice here? I don't mind vendor
> > > specific compatibles being documented, but I'm reluctant to add all
> > > these compatibles for the myriads of I2C eeproms to the at24 driver. 99%
> > > are covered by the generic case.
> > > 
> > > Adding DT to CC.
> > 
> > I'd rather use some vendor string in addition to 24c02. Isn't this originally
> > an Atmel part? In that case, using "atmel,24c02" as the most generic string
> > would be appropriate,
> 
> Yeah, the at24 driver is named after Atmel chips AFAIR. Having "atmel,*"
> as the generic fallback sounds like a good solution to me, too.
> 
> > and IIRC the i2c framework will just match that with
> > the "24c02" entry in the i2c_device_id list.
> 
> True, although this behaviour is often complained about. There have been
> attempts to make i2c/spi behave like the rest of the DT world and to
> deprecate the current way. It didn't happen because of lots gory details,
> however :/

My reading of the above is that we are currently leaning towards:

	compatible = "renesas,r1ex24002", "atmel,24c02";

And we are unsure what to do about the documentation.