[PATCH 1/1] pinctrl: handle dummy state in core

[s.hauer@pengutronix.de (Sascha Hauer)]

On Wed, Apr 18, 2012 at 03:52:23PM +0200, Linus Walleij wrote:
> On Wed, Apr 18, 2012 at 2:28 PM, Sascha Hauer <s.hauer@pengutronix.de> wrote:
> 
> > Currently Dong Aisheng is working on i.MX6, we have i.MX31, i.MX35,
> > i.MX51 and i.MX53 enabled in the same defconfig. Waiting for all
> > machines turn over at once to pinctrl is illusionary. We have to make
> > drivers work with and without pinctrl. We have a bunch of bad choices:
> >
> > - create a dummy pinctrl for all boards which do not have real pinmux
> > ?support
> 
> Viable compromise.
> 
> > - ignore pinctrl_request errors in drivers.
> 
> Ugh. Not good.
> 
> > - generate and return a dummy pinctrl in the core if no real pinctrl is
> > ?found.
> >
> > (replace pinctrl with regulators or clocks, it's the same situation, and
> > it's not only i.MX specific)
> 
> Since we have dummy regulators, we should not break the design
> pattern creating more confusion.
> 
> Stephen can you live with dummy pinctrl handles emitted by the
> core, if explictly enabled by a Kconfig option?

I'd rather not make it a Kconfig option but a runtime option. With a
Kconfig option we can only chose in the defconfigs whether it won't
work on some boards or it will hide pinctrl errors on all other boards.

Create a pinctrl_provide_dummies() functions which boards can call when
they do not have pinctrl support.

Sascha

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