Re: Re[8]: [PATCH v3] mfd: syscon: Add non-DT support

From: Arnd Bergmann <arnd@arndb.de>
To: Dong Aisheng <dong.aisheng@linaro.org>
Cc: Alexander Shiyan <shc_work@mail.ru>,
	linux-kernel@vger.kernel.org,
	Samuel Ortiz <sameo@linux.intel.com>,
	Mark Brown <broonie@opensource.wolfsonmicro.com>
Subject: Re: Re[8]: [PATCH v3] mfd: syscon: Add non-DT support
Date: Wed, 20 Feb 2013 11:14:49 +0000	[thread overview]
Message-ID: <201302201114.49304.arnd@arndb.de> (raw)
In-Reply-To: <CAP1dx+xj3+PVu98pRBAOhLxvOzhwE7VNShMLmqk-jy_CgXh8GA@mail.gmail.com>

On Wednesday 20 February 2013, Dong Aisheng wrote:
> On 20 February 2013 18:06, Arnd Bergmann <arnd@arndb.de> wrote:
> > I would first like to get an answer to the question I asked in my first mail,
> > which is what the use case of non-DT support in this driver is. If this
> > is used only by a new platform that has to use DT anyway, or by an existing
> > platform that is easy enough to convert, we probably shouldn't do all this
> > at all.
> >
> 
> If the platform can convert to dt, then we do not have such issue.
> The question is do we allow the existing non-dt platforms to use it
> before converting?

I think the answer to that is "it depends". It's basically a question of
how much work it would be to convert the platforms that need it over to
DT, and how much of the interface it actually needs. E.g. if there is
only one in-tree platform that needs to use syscon but can't easily be
moved over to DT, but that platform can only have a single syscon device,
then we don't need any of the matching support but could simply return
the first regmap area we have in the list.

Of course, if the platform in question is out of tree, I would argue
that the whatever patches are needed by that platform should also
remain out of tree.

	Arnd