On Thu, Dec 15, 2011 at 08:59:28AM +0000, Dong Aisheng-B29396 wrote:

quoted

-----Original Message-----
From: Linus Walleij [mailto:linus.walleij at linaro.org]
Sent: Thursday, December 15, 2011 4:27 PM
To: Guo Shawn-R65073
Cc: Sascha Hauer; Dong Aisheng-B29396; linus.walleij at stericsson.com;
linux-kernel at vger.kernel.org; rob.herring at calxeda.com;
grant.likely at secretlab.ca; linux-arm-kernel at lists.infradead.org;
kernel at pengutronix.de
Subject: Re: [RFC PATCH v2 4/4] mmc: sdhci-esdhc-imx: using pinmux
subsystem
Importance: High

On Thu, Dec 15, 2011 at 8:05 AM, Shawn Guo [off-list ref]
wrote:

quoted

[Me]

quoted

So if you want to do this for i.MX you need something like selectable
dummy pinmuxes, i.e. pinmux_get() to return something that just say
"OK" to everything like the dummy regulators.

Shall I try to create something like that?

Isn't the empty functions defined in include/linux/pinctrl/pinmux.h
for this purpose?

No, these are for compiling it *out*, dummy pinmuxes would be if you
compile it *in*, but don't find an apropriate pinmux, you still get
something that does nothing and still works.

Dummy regulators work exactly this way.

I did not read the dummy regulator code too much.
But does it mean that the dummy regulator or dummy pinmux will also hide the
Real errors since it will always get a available one?
How do we distinguish between the two case(real error and fake error)?

We don't :(

That's the problem with the dummy regulator.

Sascha

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