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

From: Mark Brown
Date: Wed May 28 2014 - 05:45:32 EST


On Tue, May 27, 2014 at 02:40:15PM -0700, Stephen Boyd wrote:
> On 05/24/14 05:48, Mark Brown wrote:

> > 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 <sboyd@xxxxxxxxxxxxxx>
> Subject: [PATCH] regulator: Fix regulator_get_{optional,exclusive}()
> documentation

Documentation/SubmittingPatches.

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