[PATCH v2 3/4] ASoC: core: add optional pcm_new callback for DAI driver

[Arnaud Pouliquen]

During probe, DAIs can need to perform some actions that requests
the knowledge of the pcm runtime handle.
The callback is called during DAIs linking, after PCM device creation.
For instance this can be used to add relation ship between a DAI pcm
control and the pcm device.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen at st.com>
---
 include/sound/soc-dai.h |  3 +++
 sound/soc/soc-core.c    | 28 ++++++++++++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/include/sound/soc-dai.h b/include/sound/soc-dai.h
index 964b7de..960990e 100644
--- a/include/sound/soc-dai.h
+++ b/include/sound/soc-dai.h
@@ -231,6 +231,9 @@ struct snd_soc_dai_driver {
 	int (*resume)(struct snd_soc_dai *dai);
 	/* compress dai */
 	int (*compress_new)(struct snd_soc_pcm_runtime *rtd, int num);
+	/* Optional Callback used at pcm creation*/
+	int (*pcm_new)(struct snd_soc_pcm_runtime *rtd,
+		       struct snd_soc_dai *dai);
 	/* DAI is also used for the control bus */
 	bool bus_control;
 
diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 4afa8db..d3a6c22 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -1552,6 +1552,27 @@ static int soc_probe_dai(struct snd_soc_dai *dai, int order)
 	return 0;
 }
 
+static int soc_link_dai_pcm_new(struct snd_soc_dai **dais, int num_dais,
+				struct snd_soc_pcm_runtime *rtd)
+{
+	int i, ret = 0;
+
+	for (i = 0; i < num_dais; ++i) {
+		struct snd_soc_dai_driver *drv = dais[i]->driver;
+
+		if (!rtd->dai_link->no_pcm && drv->pcm_new)
+			ret = drv->pcm_new(rtd, dais[i]);
+		if (ret < 0) {
+			dev_err(dais[i]->dev,
+				"ASoC: Failed to bind %s with pcm device\n",
+				dais[i]->name);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
 static int soc_link_dai_widgets(struct snd_soc_card *card,
 				struct snd_soc_dai_link *dai_link,
 				struct snd_soc_pcm_runtime *rtd)
@@ -1663,6 +1684,13 @@ static int soc_probe_link_dais(struct snd_soc_card *card,
 				       dai_link->stream_name, ret);
 				return ret;
 			}
+			ret = soc_link_dai_pcm_new(&cpu_dai, 1, rtd);
+			if (ret < 0)
+				return ret;
+			ret = soc_link_dai_pcm_new(rtd->codec_dais,
+						   rtd->num_codecs, rtd);
+			if (ret < 0)
+				return ret;
 		} else {
 			INIT_DELAYED_WORK(&rtd->delayed_work,
 						codec2codec_close_delayed_work);
-- 
1.9.1