ASoC: simple-card-utils: add asoc_simple_card_of_parse_routing()

Current simple card drivers are parsing routing on each own driver.
Encapsulation is one of simple card util's purpose.
Let's add asoc_simple_card_of_parse_routing for it.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

include/sound/simple_card_utils.h

@@ -100,4 +100,8 @@ void asoc_simple_card_convert_fixup(struct asoc_simple_card_data *data,
 void asoc_simple_card_parse_convert(struct device *dev, char *prefix,
 				    struct asoc_simple_card_data *data);
 
+int asoc_simple_card_of_parse_routing(struct snd_soc_card *card,
+				      char *prefix,
+				      int optional);
+
 #endif /* __SIMPLE_CARD_UTILS_H */

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

@@ -375,6 +375,28 @@ int asoc_simple_card_clean_reference(struct snd_soc_card *card)
 }
 EXPORT_SYMBOL_GPL(asoc_simple_card_clean_reference);
 
+int asoc_simple_card_of_parse_routing(struct snd_soc_card *card,
+				      char *prefix,
+				      int optional)
+{
+	struct device_node *node = card->dev->of_node;
+	char prop[128];
+
+	if (!prefix)
+		prefix = "";
+
+	snprintf(prop, sizeof(prop), "%s%s", prefix, "routing");
+
+	if (!of_property_read_bool(node, prop)) {
+		if (optional)
+			return 0;
+		return -EINVAL;
+	}
+
+	return snd_soc_of_parse_audio_routing(card, prop);
+}
+EXPORT_SYMBOL_GPL(asoc_simple_card_of_parse_routing);
+
 /* Module information */
 MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");
 MODULE_DESCRIPTION("ALSA SoC Simple Card Utils");