Re: [PATCH v7 0/7] i2c-atr and FPDLink

[Tomi Valkeinen]

On 19/01/2023 10:43, Luca Ceresoli wrote:
> Hi Andy,
>
> On Wed, 18 Jan 2023 19:43:23 +0200
> Andy Shevchenko <andriy.shevchenko@xxxxxxxxx> wrote:
>
> > On Wed, Jan 18, 2023 at 07:28:20PM +0200, Tomi Valkeinen wrote:
> > > On 18/01/2023 18:01, Andy Shevchenko wrote:
> > > > On Wed, Jan 18, 2023 at 02:40:24PM +0200, Tomi Valkeinen wrote:
> > > > > Hi,
> > > > >
> > > > > You can find the v6 from:
> > > > >
> > > > > https://lore.kernel.org/all/20230105140307.272052-1-tomi.valkeinen@xxxxxxxxxxxxxxxx/
> > > > >
> > > > > Main changes:
> > > > >
> > > > > * i2c-atr: Use bus notifier. This allows us to drop the patch that adds
> > > > >     the attach_client/detach_client callbacks. On the downside, it removes
> > > > >     the option for error handling if the translation setup fails, and also
> > > > >     doesn't provide us the pointer to the i2c_board_info. I belive both
> > > > >     are acceptable downsides.
> > > > >
> > > > > * Use fwnode in the fpdlink drivers instead of OF
> > > > >
> > > > > * Addressed all the review comments (I hope)
> > > > >
> > > > > * Lots of cosmetic or minor fixes which I came up while doing the fwnode
> > > > >     change
> > > >
> > > > I believe my comments to the first driver applies to the next two, so please
> > > > address them whenever you are agree / it's possible / it makes sense.
> > > >
> > > > About ATR implementation. We have the i2c bus (Linux representation of
> > > > the driver model) and i2c_adapter and i2c_client objects there. Can't we
> > > > have an i2c_client_aliased in similar way and be transparent with users?
> >
> > > Can you clarify what you mean here?
> > >
> > > The i2c_clients are not aware of the i2c-atr. They are normal i2c clients.
> > > The FPD-Link drivers are aware of the ATR, as the FPD-Link hardware contains
> > > the ATR support.
> >
> > Can't that hardware be represented as I2C adapter? In such case the ATR specifics
> > can be hidden from the client (drivers).
> >
> > I'm worrying about code duplication and other things that leak into drivers as
> > ATR callbacks.
>
> Which callbacks do you refer to? i2c_atr_ops? I don't think we can do
> without the attach/detach_client ones, it's where the driver-specific
> implementation is hooked for the generic ATR infra to call it.
>
> However now I noticed the select/deselect ops are still there. IIRC
> they are not used by any driver and in the past the plan was to just
> remove them. Tomi, do you think there is a good reason to keep them?

I thought you had a reason to add them, so I didn't remove them =). I 
can drop them.

 Tomi