Subject: Re: [alsa-devel] [PATCH v5 1/2] ASoC: fsl: Add S/PDIF CPU DAI driver

From: Mark Brown <[email-masked]>
Date: Sat, 24 Aug 2013 01:20:00 +0100

On Fri, Aug 23, 2013 at 02:41:44PM -0700, Mike Turquette wrote:

> Seems like the regulator framework is solving this with the new
> regulator_get_optional() call. This leaves the
> optional-versus-not-optional logic up to the driver.

That is possibly for a slightly different case but perhaps not...

The problem we've got with the regulator API is that an awful lot of
regulators are always on and people generally don't want to go and hook
everything up, especially when drivers don't yet have regulator support.
This means that we end up with lots of complaints about having to add
regultors and lots of pain adding regulator support to widely used
devices, or drivers that just ignore errors which is not awesome.

We don't want to provide dummies since if the driver genuinely does have
optional regulators they tend to break them so we're adding that call to
allow the core to know if it can just provide a stub and assume the
board data was lazy.

My impression with clocks on most platforms is that there are fewer of
this sort of always on clock, though that said I know there has been a
bit of an issue with some of the IP clocks when IPs are used in SoCs
from less power sensitive environments that don't bother implementing
gating even in hardware.