Re: [PATCH RFC] eeprom: at24: extend driver to plug into the NVMEM framework

[Srinivas Kandagatla]

On 17/08/15 16:25, Andrew Lunn wrote:
> On Mon, Aug 17, 2015 at 03:59:23PM +0100, Srinivas Kandagatla wrote:
> > On 17/08/15 14:09, Andrew Lunn wrote:
> > > On Mon, Aug 17, 2015 at 02:01:24PM +0100, Srinivas Kandagatla wrote:
> > > > +Adding Maxime in the loop
> > > >
> > > > On 16/08/15 16:37, Stefan Wahren wrote:
> > > > > > > Another question which spring to mind is, do we want the eeprom to be
> > > > > > > in /sys twice, the old and the new way? Backwards compatibility says
> > > > > > > the old must stay. Do we want a way to suppress the new? Or should we
> > > > > > > be going as far as refractoring the code into a core library, and two
> > > > > > > wrapper drivers, old and new?
> > > > > I think these are questions for the framework maintainers.
> > > > One of the reasons for the NVMEM framework is to remove that
> > > > duplicate code in the every driver.  There was no framework/ABI
> > > > which was guiding such old eeprom sysfs entry in first place, so I
> > > > dont see an issue in removing it for good. Correct me if am wrong.
> > >
> > > The reason for keeping it is backwards compatibility. Having the
> > > contents of the EEPROM as a file in /sys via this driver is now a part
> > > of the Linux ABI. You cannot argue it is not an ABI, just because
> > > there is no framework. Userspace will be assuming it exists at the
> > > specified location. So we cannot remove it, for existing uses of the
> > > driver.
> > Am Ok as long as someone is happy to maintain it.
>
> Wolfram Sang has been maintaining the AT24 driver since 2008. We need
> his ACK to this change, and since this is an i2c driver, he is also
> probably the path into mainline for this change.
>
> But we should also look at the bigger picture. The AT25, MAX6875 and
> sunxi_sid drivers also have a binary file in /sys. It would be good to
> have some sort of plan what to do with these drivers, even if at the
> moment only AT24 is under discussion.#

+1


>         Andrew
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