Re: [PATCH] ASoC: core: Support INPUT and OUTPUT DAPM widgets in DT

[Ivaylo Dimitrov]

On 5.08.26 г. 20:23 ч., Mark Brown wrote:
> On Wed, Aug 05, 2026 at 08:16:10PM +0300, Ivaylo Dimitrov wrote:
>
> > I have an out-of-tree audio-graph-card2 based machine description for
> > Motorola OMAP4 devices using the CPCAP codec together with an external modem
> > codec. Without modelling the remote endpoint as a DAPM INPUT/OUTPUT widget,
> > the DAPM graph is incomplete and one side of the codec-to-codec link does
> > not become active as expected, so runtime PM does not resume one of the
> > devices in the link during a call.
>
> Why is it appropriate that the remote endpoint be a raw widget of this
> non-specific type?
>
> > I used INPUT/OUTPUT because they appear to be the generic DAPM endpoint
> > widgets for this type of digital connection. If there is a more appropriate
> > existing widget type for modelling such a remote DAI endpoint, I'd be happy
> > to use that instead.
>
> If it's a DAI to DAI link you need a custom machine driver, we don't
> have anything like the infrastructure to put DAI<->DAI links in DT.
> These should be using AIF widgets.

Thanks for the pointer. It turned out that everything needed was already 
there; I had simply misunderstood the codec2codec example (or perhaps it 
could be a bit clearer).

The missing piece was to route the modem DAI stream widgets to the CPCAP 
AIF widgets in the audio-graph-card2 routing:

/* codec2codec */
"Voice RX", "Voice Call Playback",
"Voice Call Capture", "Voice TX";

With that in place, the codec-to-codec DAPM graph is complete and voice 
calls work correctly, so there is no need for my DT parser patch after all.

I'm sending this follow-up mainly as a reference in case someone else 
runs into the same issue in the future.

Thanks again for pointing me in the right direction.

Best regards,
Ivo