From: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
To: Luca Ceresoli <luca.ceresoli@bootlin.com>,
Andy Shevchenko <andriy.shevchenko@intel.com>
Cc: linux-media@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org,
"Rob Herring" <robh+dt@kernel.org>,
"Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>,
"Wolfram Sang" <wsa@kernel.org>,
"Matti Vaittinen" <Matti.Vaittinen@fi.rohmeurope.com>,
"Laurent Pinchart" <laurent.pinchart+renesas@ideasonboard.com>,
"Mauro Carvalho Chehab" <mchehab@kernel.org>,
"Peter Rosin" <peda@axentia.se>,
"Liam Girdwood" <lgirdwood@gmail.com>,
"Mark Brown" <broonie@kernel.org>,
"Sakari Ailus" <sakari.ailus@linux.intel.com>,
"Michael Tretter" <m.tretter@pengutronix.de>,
"Shawn Tu" <shawnx.tu@intel.com>,
"Hans Verkuil" <hverkuil@xs4all.nl>,
"Mike Pagano" <mpagano@gentoo.org>,
"Krzysztof Hałasa" <khalasa@piap.pl>,
"Marek Vasut" <marex@denx.de>
Subject: Re: [PATCH v7 0/7] i2c-atr and FPDLink
Date: Fri, 20 Jan 2023 18:20:53 +0200 [thread overview]
Message-ID: <515a21fa-17f4-1f73-ed5c-adcc7f74ddb3@ideasonboard.com> (raw)
In-Reply-To: <20230120171718.3674af61@booty>
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
prev parent reply other threads:[~2023-01-20 16:21 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-18 12:40 [PATCH v7 0/7] i2c-atr and FPDLink Tomi Valkeinen
2023-01-18 12:40 ` [PATCH v7 1/7] i2c: add I2C Address Translator (ATR) support Tomi Valkeinen
2023-01-18 14:23 ` Andy Shevchenko
2023-01-18 17:17 ` Luca Ceresoli
2023-01-18 17:39 ` Andy Shevchenko
2023-01-19 8:21 ` Luca Ceresoli
2023-01-19 10:09 ` Tomi Valkeinen
2023-01-19 11:35 ` Luca Ceresoli
2023-01-19 12:22 ` Tomi Valkeinen
2023-01-19 13:00 ` Luca Ceresoli
2023-01-20 9:55 ` Laurent Pinchart
2023-01-20 13:58 ` Luca Ceresoli
2023-01-19 12:39 ` Tomi Valkeinen
2023-01-19 13:08 ` Luca Ceresoli
2023-01-19 10:01 ` Tomi Valkeinen
2023-01-20 15:58 ` Andy Shevchenko
2023-01-20 16:00 ` Tomi Valkeinen
2023-01-18 12:40 ` [PATCH v7 2/7] dt-bindings: media: add TI DS90UB913 FPD-Link III Serializer Tomi Valkeinen
2023-01-18 12:40 ` [PATCH v7 3/7] dt-bindings: media: add TI DS90UB953 " Tomi Valkeinen
2023-01-18 12:40 ` [PATCH v7 4/7] dt-bindings: media: add TI DS90UB960 FPD-Link III Deserializer Tomi Valkeinen
2023-01-19 23:24 ` Laurent Pinchart
2023-01-18 12:40 ` [PATCH v7 5/7] media: i2c: add DS90UB960 driver Tomi Valkeinen
2023-01-18 15:48 ` Andy Shevchenko
2023-01-19 16:27 ` Tomi Valkeinen
2023-01-19 23:19 ` Laurent Pinchart
2023-01-20 16:47 ` Andy Shevchenko
2023-01-25 11:15 ` Tomi Valkeinen
2023-01-25 12:10 ` Andy Shevchenko
2023-01-25 13:33 ` Tomi Valkeinen
2023-01-25 14:49 ` Andy Shevchenko
2023-01-25 15:14 ` Tomi Valkeinen
2023-01-25 15:27 ` Andy Shevchenko
2023-01-26 8:41 ` Tomi Valkeinen
2023-01-26 10:21 ` Andy Shevchenko
2023-01-26 10:51 ` Laurent Pinchart
2023-01-27 8:24 ` Tomi Valkeinen
2023-01-27 9:15 ` Andy Shevchenko
2023-02-08 15:10 ` Tomi Valkeinen
2023-02-09 10:54 ` Laurent Pinchart
2023-01-18 12:40 ` [PATCH v7 6/7] media: i2c: add DS90UB913 driver Tomi Valkeinen
2023-01-20 0:03 ` Laurent Pinchart
2023-01-20 7:04 ` Tomi Valkeinen
2023-01-20 9:06 ` Laurent Pinchart
2023-01-18 12:40 ` [PATCH v7 7/7] media: i2c: add DS90UB953 driver Tomi Valkeinen
2023-01-20 0:34 ` Laurent Pinchart
2023-01-20 8:13 ` Tomi Valkeinen
2023-01-20 9:23 ` Laurent Pinchart
2023-01-18 16:01 ` [PATCH v7 0/7] i2c-atr and FPDLink Andy Shevchenko
2023-01-18 17:28 ` Tomi Valkeinen
2023-01-18 17:43 ` Andy Shevchenko
2023-01-19 8:43 ` Luca Ceresoli
2023-01-19 12:40 ` Tomi Valkeinen
2023-01-19 13:19 ` Luca Ceresoli
2023-01-20 16:00 ` Andy Shevchenko
2023-01-20 16:17 ` Luca Ceresoli
2023-01-20 16:20 ` Tomi Valkeinen [this message]
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