linux-kernel - Re: [PATCH v3 1/2] ASoC: codecs: add TA5720 digital amplifier DT bindings

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Date:	Tue, 26 Apr 2016 11:14:25 -0500
From:	Andreas Dannenberg <dannenberg@...com>
To:	Mark Brown <broonie@...nel.org>
CC:	<alsa-devel@...a-project.org>, <devicetree@...r.kernel.org>,
	Liam Girdwood <lgirdwood@...il.com>,
	Jaroslav Kysela <perex@...ex.cz>,
	Takashi Iwai <tiwai@...e.com>,
	Rob Herring <robh+dt@...nel.org>,
	Pawel Moll <pawel.moll@....com>,
	Mark Rutland <mark.rutland@....com>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Kumar Gala <galak@...eaurora.org>,
	<linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3 1/2] ASoC: codecs: add TA5720 digital amplifier DT
 bindings

On Tue, Apr 26, 2016 at 04:37:07PM +0100, Mark Brown wrote:
> On Mon, Apr 25, 2016 at 03:17:35PM -0500, Andreas Dannenberg wrote:
> 
> > +Optional properties:
> > +
> > +- dvdd-supply : phandle to a 3.3-V supply for the digital circuitry
> > +- pvdd-supply : phandle to a supply used for the Class-D amp and the analog
> 
> This suggests that the device doesn't need power...  

Hi Mark,
no power, now that would be nice! :)  What this was supposed to mean is
that the properties are optional, the power of course is not. The DT has
really no control over how I wire up my HW and I'd argue most folks just
permanently power the TAS5720 since the shutdown current is just a few
uAs IIRC in order to save some BOM cost. But I suppose the DT description
is such that the Kernel can more intelligently handle things based on
what the driver is doing if somebody choses and implements additional
regulator/power switch HW. Or did I misunderstand your point?

Thanks,
Andreas