ASoC: audio-graph-card: tidyup prefix for snd_soc_codec_conf

Current audio-graph-card is handling "prefix" by many ways.
But, it is not useful and readable.
We want to do is that allow having it everywere.
This patch supports it.
It will be overwrote if lower node has it.

	sound {
		prefix = "xxx"; // initial
	};

	codec {
		audio-graph-card,prefix = "xxx"; // overwrite
		ports {
			prefix = "xxx"; // overwrite
			port {
				prefix = "xxx"; // overwrite
			};
		};
	};

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

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

@@ -179,12 +179,12 @@ static int asoc_graph_card_dai_link_of_dpcm(struct device_node *top,
 	struct device *dev = graph_priv_to_dev(priv);
 	struct snd_soc_dai_link *dai_link = graph_priv_to_link(priv, link_idx);
 	struct graph_dai_props *dai_props = graph_priv_to_props(priv, link_idx);
-	struct snd_soc_card *card = graph_priv_to_card(priv);
 	struct device_node *ep = is_cpu ? cpu_ep : codec_ep;
 	struct device_node *port = of_get_parent(ep);
 	struct device_node *ports = of_get_parent(port);
 	struct device_node *node = of_graph_get_port_parent(ep);
 	struct asoc_simple_dai *dai;
+	struct snd_soc_dai_link_component *codecs = dai_link->codecs;
 	int ret;
 
 	dev_dbg(dev, "link_of DPCM (for %s)\n", is_cpu ? "CPU" : "Codec");
@@ -204,10 +204,8 @@ static int asoc_graph_card_dai_link_of_dpcm(struct device_node *top,
 	of_node_put(port);
 
 	if (is_cpu) {
-		struct snd_soc_dai_link_component *codecs;
 
 		/* BE is dummy */
-		codecs			= dai_link->codecs;
 		codecs->of_node		= NULL;
 		codecs->dai_name	= "snd-soc-dummy-dai";
 		codecs->name		= "snd-soc-dummy";
@@ -264,19 +262,19 @@ static int asoc_graph_card_dai_link_of_dpcm(struct device_node *top,
 
 		ret = asoc_simple_card_set_dailink_name(dev, dai_link,
 							"be.%s",
-							dai_link->codecs->dai_name);
+							codecs->dai_name);
 		if (ret < 0)
 			return ret;
 
 		/* check "prefix" from top node */
-		snd_soc_of_parse_audio_prefix(card, cconf,
-					      dai_link->codecs->of_node,
+		snd_soc_of_parse_node_prefix(top, cconf, codecs->of_node,
 					      "prefix");
-		/* check "prefix" from each node if top doesn't have */
-		if (!cconf->of_node)
-			snd_soc_of_parse_node_prefix(node, cconf,
-						     dai_link->codecs->of_node,
-						     PREFIX "prefix");
+		snd_soc_of_parse_node_prefix(node, cconf, codecs->of_node,
+					     PREFIX "prefix");
+		snd_soc_of_parse_node_prefix(ports, cconf, codecs->of_node,
+					     "prefix");
+		snd_soc_of_parse_node_prefix(port, cconf, codecs->of_node,
+					     "prefix");
 	}
 
 	ret = asoc_simple_card_of_parse_tdm(ep, dai);