[RFC PATCH 1/2] ASoC: simple-card: Introduce force-dpcm DT property

[Daniel Baluta]

Until now dai_link uses dynamic PCM in the following conditions:
	* it is dpcm_selectable (this means compatible string is simple-scu-card)
	* it has convert-xxx property
	* or it has more than one CPU DAIs

Our use case requires to be able to build a DPCM link with just 1 CPU.
Add force-dpcm DT property to realize this.

Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxx>
---
 include/sound/simple_card_utils.h     |  4 ++++
 sound/soc/generic/simple-card-utils.c | 17 +++++++++++++++++
 sound/soc/generic/simple-card.c       | 25 +++++++++++++++++++++++--
 3 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/include/sound/simple_card_utils.h b/include/sound/simple_card_utils.h
index 985a5f583de4..0578bbfa4a24 100644
--- a/include/sound/simple_card_utils.h
+++ b/include/sound/simple_card_utils.h
@@ -48,6 +48,7 @@ struct asoc_simple_priv {
 		struct asoc_simple_data adata;
 		struct snd_soc_codec_conf *codec_conf;
 		unsigned int mclk_fs;
+		unsigned int force_dpcm;
 	} *dai_props;
 	struct asoc_simple_jack hp_jack;
 	struct asoc_simple_jack mic_jack;
@@ -120,6 +121,9 @@ void asoc_simple_convert_fixup(struct asoc_simple_data *data,
 void asoc_simple_parse_convert(struct device *dev,
 			       struct device_node *np, char *prefix,
 			       struct asoc_simple_data *data);
+void asoc_simple_parse_force_dpcm(struct device *dev,
+				  struct device_node *np, char *prefix,
+				  unsigned int *force_dpcm);
 
 int asoc_simple_parse_routing(struct snd_soc_card *card,
 				      char *prefix);
diff --git a/sound/soc/generic/simple-card-utils.c b/sound/soc/generic/simple-card-utils.c
index 9b794775df53..2f03a73f8a8a 100644
--- a/sound/soc/generic/simple-card-utils.c
+++ b/sound/soc/generic/simple-card-utils.c
@@ -52,6 +52,23 @@ void asoc_simple_parse_convert(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(asoc_simple_parse_convert);
 
+void asoc_simple_parse_force_dpcm(struct device *dev,
+			       struct device_node *np,
+			       char *prefix,
+			       unsigned int *force_dpcm)
+{
+	char prop[128];
+
+	if (!prefix)
+		prefix = "";
+
+	/* dpcm property */
+	snprintf(prop, sizeof(prop), "%s%s", prefix, "force-dpcm");
+	if (of_find_property(np, prop, NULL))
+		*force_dpcm = 1;
+}
+EXPORT_SYMBOL_GPL(asoc_simple_parse_force_dpcm);
+
 int asoc_simple_parse_daifmt(struct device *dev,
 			     struct device_node *node,
 			     struct device_node *codec,
diff --git a/sound/soc/generic/simple-card.c b/sound/soc/generic/simple-card.c
index fc9c753db8dd..e40e22c8813b 100644
--- a/sound/soc/generic/simple-card.c
+++ b/sound/soc/generic/simple-card.c
@@ -92,6 +92,21 @@ static void simple_parse_convert(struct device *dev,
 	of_node_put(node);
 }
 
+static void simple_parse_force_dpcm(struct device *dev,
+				 struct device_node *np,
+				 unsigned int *force_dpcm)
+{
+	struct device_node *top = dev->of_node;
+	struct device_node *node = of_get_parent(np);
+
+	asoc_simple_parse_force_dpcm(dev, top,  PREFIX, force_dpcm);
+	asoc_simple_parse_force_dpcm(dev, node, PREFIX, force_dpcm);
+	asoc_simple_parse_force_dpcm(dev, node, NULL,   force_dpcm);
+	asoc_simple_parse_force_dpcm(dev, np,   NULL,   force_dpcm);
+
+	of_node_put(node);
+}
+
 static void simple_parse_mclk_fs(struct device_node *top,
 				 struct device_node *cpu,
 				 struct device_node *codec,
@@ -372,6 +387,7 @@ static int simple_for_each_link(struct asoc_simple_priv *priv,
 		struct asoc_simple_data adata;
 		struct device_node *codec;
 		struct device_node *np;
+		unsigned int force_dpcm = 0;
 		int num = of_get_child_count(node);
 
 		/* get codec */
@@ -387,15 +403,20 @@ static int simple_for_each_link(struct asoc_simple_priv *priv,
 		for_each_child_of_node(node, np)
 			simple_parse_convert(dev, np, &adata);
 
+		/* get force-dpcm property */
+		for_each_child_of_node(node, np)
+			simple_parse_force_dpcm(dev, np, &force_dpcm);
+
 		/* loop for all CPU/Codec node */
 		for_each_child_of_node(node, np) {
 			/*
 			 * It is DPCM
 			 * if it has many CPUs,
-			 * or has convert-xxx property
+			 * or it has convert-xxx property
+			 * or it has force-dpcm property
 			 */
 			if (dpcm_selectable &&
-			    (num > 2 ||
+			    (num > 2 || force_dpcm ||
 			     adata.convert_rate || adata.convert_channels))
 				ret = func_dpcm(priv, np, codec, li, is_top);
 			/* else normal sound */
-- 
2.17.1