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From: Arnd Bergmann <arnd@arndb.de>
To: Linus Walleij <linus.walleij@linaro.org>
Subject: Re: [PATCH 02/12] pinctrl: basic Nomadik pinctrl interface
Date: Thu, 10 May 2012 15:57:12 +0000
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On Thursday 10 May 2012, Arnd Bergmann wrote:
> > >
> > > Arnd, what is your preferred design pattern of:
> > >
> > > A) sub-drivers that register one struct platform_driver per
> > >  variant, then calls into a shared core driver, or
> > >
> > > B) a shared core driver registering one platform_driver
> > >  with several struct platform_device_id that then call
> > >  sub-drivers depending on which one is found
> > >
> > > Either way is actually OK for me, but I was thinking if one
> > > is preferred over the other.
> 
> Out of those two, I'd always pick B.
> 
> In cases where the variants are different enough that you want to
> put them into separate files, I'd do
> 
> C) Make the common code one module that just exports symbols but
> registers no platform_driver at all, then put each variant into
> its own module that binds to one ID and calls the exported
> functions from the common module.
> 

Sorry, I guess A and C are actually the same and I just misread the
question.

So I'd use A for things that are different enough to put them
into separate files, and B for things where I'd always build
all variants in the same driver module anyway, e.g. when only
a few parameters are different.

	Arnd