ASoC: simple-card-utils: share dummy DAI and reduce memory

Current simple-card / audio-graph creates 1xCPU + 1xCodec + 1xPlatform
for all dai_link, but some of them is not needed.
For example Platform is not needed for DPCM BE case.
Moreover, we can share snd-soc-dummy DAI for CPU-dummy / dummy-Codec
in DPCM.

This patch adds dummy DAI and share it when DPCM case,
I beliave it can contribute to reduce memory.

By this patch, CPU-dummy / dummy-CPU are set at asoc_simple_init_priv(),
thus, its settings are no longer needed at DPCM detecting timing
on simple-card / audio-graph.
Moreover, we can remove triky Platform settings code for DPCM BE,
because un-needed Platform is not created.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87tuoqod22.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>

include/sound/simple_card_utils.h

@@ -62,6 +62,7 @@ struct asoc_simple_priv {
 	struct snd_soc_dai_link *dai_link;
 	struct asoc_simple_dai *dais;
 	struct snd_soc_dai_link_component *dlcs;
+	struct snd_soc_dai_link_component dummy;
 	struct snd_soc_codec_conf *codec_conf;
 	struct gpio_desc *pa_gpio;
 	const struct snd_soc_ops *ops;

sound/soc/generic/audio-graph-card.c

@@ -240,9 +240,6 @@ static int graph_dai_link_of_dpcm(struct asoc_simple_priv *priv,
 		int is_single_links = 0;
 
 		/* Codec is dummy */
-		codecs->of_node		= NULL;
-		codecs->dai_name	= "snd-soc-dummy-dai";
-		codecs->name		= "snd-soc-dummy";
 
 		/* FE settings */
 		dai_link->dynamic		= 1;
@@ -281,13 +278,11 @@ static int graph_dai_link_of_dpcm(struct asoc_simple_priv *priv,
 
 		/* card->num_links includes Codec */
 		asoc_simple_canonicalize_cpu(dai_link, is_single_links);
+		asoc_simple_canonicalize_platform(dai_link);
 	} else {
 		struct snd_soc_codec_conf *cconf;
 
 		/* CPU is dummy */
-		cpus->of_node		= NULL;
-		cpus->dai_name		= "snd-soc-dummy-dai";
-		cpus->name		= "snd-soc-dummy";
 
 		/* BE settings */
 		dai_link->no_pcm		= 1;
@@ -328,8 +323,6 @@ static int graph_dai_link_of_dpcm(struct asoc_simple_priv *priv,
 	graph_parse_convert(dev, ep, &dai_props->adata);
 	graph_parse_mclk_fs(top, ep, dai_props);
 
-	asoc_simple_canonicalize_platform(dai_link);
-
 	ret = asoc_simple_parse_tdm(ep, dai);
 	if (ret)
 		goto out_put_node;
@@ -659,15 +652,12 @@ static int graph_count_dpcm(struct asoc_simple_priv *priv,
 
 	if (li->cpu) {
 		li->num[li->link].cpus		= 1;
-		li->num[li->link].codecs	= 1;
 		li->num[li->link].platforms	= 1;
 
 		li->link++; /* 1xCPU-dummy */
 		li->dais++; /* 1xCPU */
 	} else {
-		li->num[li->link].cpus		= 1;
 		li->num[li->link].codecs	= 1;
-		li->num[li->link].platforms	= 1;
 
 		li->link++; /* 1xdummy-Codec */
 		li->conf++; /* 1xdummy-Codec */

sound/soc/generic/simple-card-utils.c

@@ -404,13 +404,6 @@ void asoc_simple_canonicalize_platform(struct snd_soc_dai_link *dai_link)
 	/* Assumes platform == cpu */
 	if (!dai_link->platforms->of_node)
 		dai_link->platforms->of_node = dai_link->cpus->of_node;
-
-	/*
-	 * DPCM BE can be no platform.
-	 * Alloced memory will be waste, but not leak.
-	 */
-	if (!dai_link->platforms->of_node)
-		dai_link->num_platforms = 0;
 }
 EXPORT_SYMBOL_GPL(asoc_simple_canonicalize_platform);
 
@@ -633,6 +626,11 @@ int asoc_simple_init_priv(struct asoc_simple_priv *priv,
 			return -ENOMEM;
 	}
 
+	/* dummy CPU/Codec */
+	priv->dummy.of_node	= NULL;
+	priv->dummy.dai_name	= "snd-soc-dummy-dai";
+	priv->dummy.name	= "snd-soc-dummy";
+
 	priv->dai_props		= dai_props;
 	priv->dai_link		= dai_link;
 	priv->dais		= dais;
@@ -653,6 +651,12 @@ int asoc_simple_init_priv(struct asoc_simple_priv *priv,
 			dai_link[i].num_cpus	= li->num[i].cpus;
 
 			dlcs += li->num[i].cpus;
+		} else {
+			/* DPCM Be's CPU = dummy */
+			dai_props[i].cpus	=
+			dai_link[i].cpus	= &priv->dummy;
+			dai_props[i].num.cpus	=
+			dai_link[i].num_cpus	= 1;
 		}
 
 		if (li->num[i].codecs) {
@@ -663,6 +667,12 @@ int asoc_simple_init_priv(struct asoc_simple_priv *priv,
 			dai_link[i].num_codecs	= li->num[i].codecs;
 
 			dlcs += li->num[i].codecs;
+		} else {
+			/* DPCM Fe's Codec = dummy */
+			dai_props[i].codecs	=
+			dai_link[i].codecs	= &priv->dummy;
+			dai_props[i].num.codecs	=
+			dai_link[i].num_codecs	= 1;
 		}
 
 		if (li->num[i].platforms) {
@@ -673,6 +683,12 @@ int asoc_simple_init_priv(struct asoc_simple_priv *priv,
 			dai_link[i].num_platforms	= li->num[i].platforms;
 
 			dlcs += li->num[i].platforms;
+		} else {
+			/* Doesn't have Platform */
+			dai_props[i].platforms		=
+			dai_link[i].platforms		= NULL;
+			dai_props[i].num.platforms	=
+			dai_link[i].num_platforms	= 0;
 		}
 	}
 

sound/soc/generic/simple-card.c

@@ -141,9 +141,6 @@ static int simple_dai_link_of_dpcm(struct asoc_simple_priv *priv,
 		int is_single_links = 0;
 
 		/* Codec is dummy */
-		codecs->of_node		= NULL;
-		codecs->dai_name	= "snd-soc-dummy-dai";
-		codecs->name		= "snd-soc-dummy";
 
 		/* FE settings */
 		dai_link->dynamic		= 1;
@@ -167,13 +164,11 @@ static int simple_dai_link_of_dpcm(struct asoc_simple_priv *priv,
 			goto out_put_node;
 
 		asoc_simple_canonicalize_cpu(dai_link, is_single_links);
+		asoc_simple_canonicalize_platform(dai_link);
 	} else {
 		struct snd_soc_codec_conf *cconf;
 
 		/* CPU is dummy */
-		cpus->of_node		= NULL;
-		cpus->dai_name		= "snd-soc-dummy-dai";
-		cpus->name		= "snd-soc-dummy";
 
 		/* BE settings */
 		dai_link->no_pcm		= 1;
@@ -211,8 +206,6 @@ static int simple_dai_link_of_dpcm(struct asoc_simple_priv *priv,
 	simple_parse_convert(dev, np, &dai_props->adata);
 	simple_parse_mclk_fs(top, np, codec, dai_props, prefix);
 
-	asoc_simple_canonicalize_platform(dai_link);
-
 	ret = asoc_simple_parse_tdm(np, dai);
 	if (ret)
 		goto out_put_node;
@@ -530,15 +523,12 @@ static int simple_count_dpcm(struct asoc_simple_priv *priv,
 
 	if (li->cpu) {
 		li->num[li->link].cpus		= 1;
-		li->num[li->link].codecs	= 1;
 		li->num[li->link].platforms	= 1;
 
 		li->link++; /* CPU-dummy */
 		li->dais++;
 	} else {
-		li->num[li->link].cpus		= 1;
 		li->num[li->link].codecs	= 1;
-		li->num[li->link].platforms	= 1;
 
 		li->link++; /* dummy-Codec */
 		li->dais++;