[alsa-devel] [PATCH 00/14] SPDIF support

[Lars-Peter Clausen]

On 08/31/2013 02:34 PM, Russell King - ARM Linux wrote:
[...]
> The same conditions apply as per my previous posting - the DAI link
> needs to be setup and the associated DAPM routes to tell the CPU DAI
> which outputs are in use, like this:
> 
> DAI link:
>                 .name = "S/PDIF1",
>                 .stream_name = "IEC958 Playback",
>                 .platform_name = "mvebu-audio.1",
>                 .cpu_dai_name = "mvebu-audio.1",
>                 .codec_dai_name = "dit-hifi",
>                 .codec_name = "spdif-dit",
> 
> static const struct snd_soc_dapm_route routes[] = {
>         { "Playback", NULL, "spdifdo" },
> };

This is still not exactly the right way to implement this though. Add a
second DAI to your CPU driver, like this:

static struct snd_soc_dai_driver kirkwood_mvebu_dais[] = {
	{
		.id = 0,
		.probe = kirkwood_i2s_probe,
    		.playback = {
			.stream_name = "I2S Capture",
			...
		},
		.capture = {
			.stream_name = "I2S Playback",
			...
		},
		.ops = &kirkwood_i2s_dai_ops,
	}, {
		.id = 1,
		.probe = kirkwood_i2s_probe,
    		.playback = {
			.stream_name = "SPDIF Capture",
			...
		},
		.capture = {
			.stream_name = "SPDIF Playback",
			...
		},
		.ops = &kirkwood_i2s_dai_ops,
	},
};

Then connect the SPDIF AIF widgets to the SPDIF streams and the I2S AIF
widgets to the I2S streams. In your machine driver setup the link config to
use DAI 0 if the board uses I2S and DAI 1 if the board uses SPDIF. The ASoC
framework will then create the necessary routes all by itself. Of course
this won't work on a platform where both the SPDIF and I2S controller are
used at the same time, but neither does your current solution.

- Lars