[alsa-devel] [RFC 3/4] ASoC: Allow Aux Codecs to be specified using DT

[Sebastian Reichel]

This patch adds support for specifying auxiliary codecs and
codec configuration via device tree phandles.

This change adds new fields to snd_soc_aux_dev and snd_soc_codec_conf
and adds support for the changes to SoC core methods.

Signed-off-by: Sebastian Reichel <sre at debian.org>
---
 include/sound/soc.h  | 13 +++++++++-
 sound/soc/soc-core.c | 68 ++++++++++++++++++++++++++++++++++++----------------
 2 files changed, 59 insertions(+), 22 deletions(-)

diff --git a/include/sound/soc.h b/include/sound/soc.h
index d22cb0a..00b25a8 100644
--- a/include/sound/soc.h
+++ b/include/sound/soc.h
@@ -937,7 +937,12 @@ struct snd_soc_dai_link {
 };
 
 struct snd_soc_codec_conf {
+	/*
+	 * specify device either by device name, or by
+	 * DT/OF node, but not both.
+	 */
 	const char *dev_name;
+	const struct device_node *of_node;
 
 	/*
 	 * optional map of kcontrol, widget and path name prefixes that are
@@ -954,7 +959,13 @@ struct snd_soc_codec_conf {
 
 struct snd_soc_aux_dev {
 	const char *name;		/* Codec name */
-	const char *codec_name;		/* for multi-codec */
+
+	/*
+	 * specify multi-codec either by device name, or by
+	 * DT/OF node, but not both.
+	 */
+	const char *codec_name;
+	const struct device_node *codec_of_node;
 
 	/* codec/machine specific init - e.g. add machine controls */
 	int (*init)(struct snd_soc_dapm_context *dapm);
diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 1a38be0..392f479 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -1085,10 +1085,12 @@ static void soc_set_name_prefix(struct snd_soc_card *card,
 
 	for (i = 0; i < card->num_configs; i++) {
 		struct snd_soc_codec_conf *map = &card->codec_conf[i];
-		if (map->dev_name && !strcmp(codec->name, map->dev_name)) {
-			codec->name_prefix = map->name_prefix;
-			break;
-		}
+		if (map->of_node && codec->dev->of_node != map->of_node)
+			continue;
+		if (map->dev_name && strcmp(codec->name, map->dev_name))
+			continue;
+		codec->name_prefix = map->name_prefix;
+		break;
 	}
 }
 
@@ -1527,15 +1529,23 @@ static void soc_unregister_ac97_dai_link(struct snd_soc_codec *codec)
 static int soc_check_aux_dev(struct snd_soc_card *card, int num)
 {
 	struct snd_soc_aux_dev *aux_dev = &card->aux_dev[num];
+	const char *codecname = aux_dev->codec_name;
 	struct snd_soc_codec *codec;
 
 	/* find CODEC from registered CODECs*/
 	list_for_each_entry(codec, &codec_list, list) {
-		if (!strcmp(codec->name, aux_dev->codec_name))
+		if (aux_dev->codec_of_node &&
+				codec->dev->of_node == aux_dev->codec_of_node)
+			return 0;
+		if (aux_dev->codec_name &&
+				!strcmp(codec->name, aux_dev->codec_name))
 			return 0;
 	}
 
-	dev_err(card->dev, "ASoC: %s not registered\n", aux_dev->codec_name);
+	if (aux_dev->codec_of_node)
+		codecname = of_node_full_name(aux_dev->codec_of_node);
+
+	dev_err(card->dev, "ASoC: %s not registered\n", codecname);
 
 	return -EPROBE_DEFER;
 }
@@ -1544,22 +1554,31 @@ static int soc_probe_aux_dev(struct snd_soc_card *card, int num)
 {
 	struct snd_soc_aux_dev *aux_dev = &card->aux_dev[num];
 	struct snd_soc_codec *codec;
+	const char *codecname = aux_dev->codec_name;
 	int ret = -ENODEV;
 
 	/* find CODEC from registered CODECs*/
 	list_for_each_entry(codec, &codec_list, list) {
-		if (!strcmp(codec->name, aux_dev->codec_name)) {
-			if (codec->probed) {
-				dev_err(codec->dev,
-					"ASoC: codec already probed");
-				ret = -EBUSY;
-				goto out;
-			}
-			goto found;
+		if (aux_dev->codec_of_node &&
+				codec->dev->of_node != aux_dev->codec_of_node)
+			continue;
+		if (aux_dev->codec_name &&
+				strcmp(codec->name, aux_dev->codec_name))
+			continue;
+
+		if (codec->probed) {
+			dev_err(codec->dev, "ASoC: codec already probed");
+			ret = -EBUSY;
+			goto out;
 		}
+		goto found;
 	}
+
+	if (aux_dev->codec_of_node)
+		codecname = of_node_full_name(aux_dev->codec_of_node);
+
 	/* codec not found */
-	dev_err(card->dev, "ASoC: codec %s not found", aux_dev->codec_name);
+	dev_err(card->dev, "ASoC: codec %s not found", codecname);
 	return -EPROBE_DEFER;
 
 found:
@@ -1644,12 +1663,19 @@ static int snd_soc_instantiate_card(struct snd_soc_card *card)
 		/* check to see if we need to override the compress_type */
 		for (i = 0; i < card->num_configs; ++i) {
 			codec_conf = &card->codec_conf[i];
-			if (!strcmp(codec->name, codec_conf->dev_name)) {
-				compress_type = codec_conf->compress_type;
-				if (compress_type && compress_type
-				    != codec->compress_type)
-					break;
-			}
+
+			if (codec_conf->of_node &&
+				codec->dev->of_node != codec_conf->of_node)
+				continue;
+
+			if (codec_conf->dev_name &&
+				strcmp(codec->name, codec_conf->dev_name))
+				continue;
+
+			compress_type = codec_conf->compress_type;
+			if (compress_type && compress_type
+			    != codec->compress_type)
+				break;
 		}
 		ret = snd_soc_init_codec_cache(codec, compress_type);
 		if (ret < 0)
-- 
1.8.4.rc3