Re: [PATCH v2 1/4] devicetree: bindings: Properly document micrel ks8851 SPI chips

On Tue, May 27, 2014 at 02:40:15PM -0700, Stephen Boyd wrote:

On 05/24/14 05:48, Mark Brown wrote:

quoted

That said it looks like this is intended to be a supply for an external
PHY rather than the device itself, but even so my original question
about it being able to operate without power still applies.  Looking at
the code it's certainly not doing any of the handling of a missing
supply that I would associate with using _optional().

I agree, both supplies don't look optional. Unfortunately
efm32gg-dk3750.dts doesn't look to be listing any supply, and this
driver only recently got support for the VDD_A3.3 supply that the omap
board uses (adding Uwe for any comments on efm setup). I presume on
these boards VDD_IO is tied to some always on power source that software
doesn't want to deal with. Nishant, what's VDD_IO connected to on omap?

What's the proper solution here? Should we use regulator_get() and check
for EPROBE_DEFER and ignore other errors?

As an implementation extension if no supply is specified at all the
regulator API will happily substitute in a dummy if the board is using
DT or ACPI, or if it has specified full constraints.

Should the get_optional() variant just drop the "Other consumers will
be... " part and should the get_exclusive() variant say "obtain this
regulator while this reference is held" ?

Yes.

From: Stephen Boyd <redacted>
Subject: [PATCH] regulator: Fix regulator_get_{optional,exclusive}()
 documentation

Documentation/SubmittingPatches.