Messages in this thread | ![/](/images/icornerl.gif) | | Date | Fri, 20 Jan 2023 18:20:53 +0200 | Subject | Re: [PATCH v7 0/7] i2c-atr and FPDLink | From | Tomi Valkeinen <> |
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On 20/01/2023 18:17, Luca Ceresoli wrote: > Hi Andy, > > On Fri, 20 Jan 2023 18:00:02 +0200 > Andy Shevchenko <andriy.shevchenko@intel.com> wrote: > >> 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? > > I hadn't sent any URL :) > > Here's the shortcut to go straight to the ATR description: > https://youtu.be/7hLv6fYAW-E?t=1350 > > Slides: > https://elinux.org/images/f/fc/Ceresoli-elce2019-video-serdes-linux.pdf
A small note: the current implementation doesn't match the slides, as the adapter is now (at least kind of) in the serializer (the "ideal solution" in the slides.
Tomi
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