Re: [PATCH RFC] arm64: dts: allwinner: a64: teres-i: Enable audio

Maxime Ripard
2019-02-12T08:39:03Z

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On Mon, Feb 11, 2019 at 08:32:35PM +0100, Harald Geyer wrote:
> > We want to model this properly. I guess using a pinctrl driver
> > controlled through GPIO (similar to what regulator-gpio is) would be a
> > good first step.
>
> I considered this too, but didn't like it:
>
> 1) Seems like a bit of overkill.
>
> 2) The HW at hand is a rather different kind of multiplexer than
> what pinctrl assumes. We don't want two mutually exclusive devices,
> (Ie don't make the kernel unbind /dev/console for the sake of audio.)
> but we want switch the jack between two devices, that might both be
> active at the same time. This looks more like the channel multiplexers
> used with many ADCs and such. I guess, I could start a new subsystem
> around this. Seems like even more overkill.

I'm not quite sure about how that's different from what pinctrl
assumes. pinctrl assumes to handle devices that have multiple signals
as input, and one as output. Isn't that exactly what you have?

And pinctrl can be used dynamically as well if you need to

> Instead I just got the original patch working, by implementing
> "output-high" DT property in sunxi-pinctrl. I'll send a patch for
> review soon.

What do you want to do with output-high exactly?

Maxime

--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

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