[alsa-devel] Using simple-card to replace kirkwood-t5325.c

Andrew Lunn andrew at lunn.ch
Tue Apr 15 18:13:02 CEST 2014

Hi Folks

I'm an ALSA newbie, so if i say anything stupid, please let me know.

I'm trying to replace sound/soc/kirkwood/kirkwood-t5325.c with DT,
using simple-card. I can get near, but i'm missing two things:

There does not appear to be a way to represent this in DT:

static int t5325_dai_init(struct snd_soc_pcm_runtime *rtd)
	struct snd_soc_codec *codec = rtd->codec;
	struct snd_soc_dapm_context *dapm = &codec->dapm;

	snd_soc_dapm_enable_pin(dapm, "Mic Jack");
	snd_soc_dapm_enable_pin(dapm, "Headphone Jack");
	snd_soc_dapm_enable_pin(dapm, "Speaker");

	return 0;

It appears that quite a few drivers need to enable pins. It also seems
common to disable pins and to set them to NC. Is this a generic enough
feature it could be added to the DT binding?

The second thing i need is:

static int t5325_hw_params(struct snd_pcm_substream *substream,
       	   struct snd_pcm_hw_params *params)
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_soc_dai *codec_dai = rtd->codec_dai;
	unsigned int freq;

	freq = params_rate(params) * 256;

	return snd_soc_dai_set_sysclk(codec_dai, 0, freq, SND_SOC_CLOCK_IN);


static struct snd_soc_ops t5325_ops = {
       .hw_params = t5325_hw_params,

This seems a lot less common requirements. All the Marvell SoCs need
it, but not many others. So i don't think it makes sense to add it
directly to simple-card, otherwise simple-card quickly becomes
complex-card as everybody else wants there quirks adding.

Has there been any thoughts about turning simple-card.c into a
library, or adding hooks so that a driver can modify the created
dai_link structures to add in ops like this?


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