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

Andy Shevchenko
2023-01-20T16:00:15Z

On Thu, Jan 19, 2023 at 09:43:58AM +0100, Luca Ceresoli wrote:
> On Wed, 18 Jan 2023 19:43:23 +0200
> Andy Shevchenko <andriy.shevchenko@intel.com> 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:

...

> > > 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?
>
> > It might be that I didn't get how hw exactly functioning on this
> > level and why we need those callbacks.
>
> As far as "how hw exactly works", in case you haven't seen that, the
> best explanation I was able to give is in my ELCE 2019 talk, at minute
> ~22. It's a 2-3 minute watch. The slides have pointers to other talks
> and discussion.

Probably I have missed the URL in the discussion, care to resend?

--
With Best Regards,
Andy Shevchenko