Re: [PATCH v7 5/7] media: i2c: add DS90UB960 driver

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Andy Shevchenko <andriy.shevchenko@intel.com>
Cc: "Tomi Valkeinen" <tomi.valkeinen@ideasonboard.com>,
	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>,
	"Luca Ceresoli" <luca.ceresoli@bootlin.com>,
	"Matti Vaittinen" <Matti.Vaittinen@fi.rohmeurope.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 5/7] media: i2c: add DS90UB960 driver
Date: Thu, 26 Jan 2023 12:51:30 +0200	[thread overview]
Message-ID: <Y9JbMjPM3Ea3RVzH@pendragon.ideasonboard.com> (raw)
In-Reply-To: <Y9JUEv66Gze8FjMZ@smile.fi.intel.com>

On Thu, Jan 26, 2023 at 12:21:06PM +0200, Andy Shevchenko wrote:
> On Thu, Jan 26, 2023 at 10:41:47AM +0200, Tomi Valkeinen wrote:
> > On 25/01/2023 17:27, Andy Shevchenko wrote:
> 
> ...
> 
> > > But I probably don't understand the ATR structure and what exactly we need to
> > > pass to it, perhaps it also can be replaced with properties (note, that we have
> > > some interesting ones that called references, which is an alternative to DT
> > > phandle).
> > 
> > Well, maybe this needs a Linux bus implementation. I'm not that familiar
> > with implementing a bus, but I think that would make it easier to share data
> > between the deserializer and the serializer. A bus sounds a bit like an
> > overkill for a 1-to-1 connection, used by a few drivers, but maybe it
> > wouldn't be too much code.
> 
> Have you looked at auxiliary bus (appeared a few releases ago in kernel)?

As far as I understand, the auxiliary bus infrastructure is meant for
use cases where a single hardware device needs to be split into multiple
logical devices (as in struct device). Platform devices were
historically (ab)used for this, and the auxiliary bus is meant as a
cleaner solution. I'm not sure if it would be a good match here, or if
it would be considered an abuse of the auxiliary bus API.

-- 
Regards,

Laurent Pinchart