ASoC: soc-utils: add snd_soc_dlc_is_dummy()

We have snd_soc_xxx_is_dummy() functions, but not for dlc.
Let's add it.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://patch.msgid.link/87cydc8vup.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: morimoto

include/sound/soc.h

@@ -935,7 +935,7 @@ snd_soc_link_to_platform(struct snd_soc_dai_link *link, int n) {
 
 extern struct snd_soc_dai_link_component null_dailink_component[0];
 extern struct snd_soc_dai_link_component snd_soc_dummy_dlc;
-
+int snd_soc_dlc_is_dummy(struct snd_soc_dai_link_component *dlc);
 
 struct snd_soc_codec_conf {
 	/*

sound/soc/soc-utils.c

@@ -262,6 +262,19 @@ struct snd_soc_dai_link_component snd_soc_dummy_dlc = {
 };
 EXPORT_SYMBOL_GPL(snd_soc_dummy_dlc);
 
+int snd_soc_dlc_is_dummy(struct snd_soc_dai_link_component *dlc)
+{
+	if (dlc == &snd_soc_dummy_dlc)
+		return true;
+
+	if (strcmp(dlc->name,	  snd_soc_dummy_dlc.name)	== 0 ||
+	    strcmp(dlc->dai_name, snd_soc_dummy_dlc.dai_name)	== 0)
+		return true;
+
+	return false;
+}
+EXPORT_SYMBOL_GPL(snd_soc_dlc_is_dummy);
+
 static int snd_soc_dummy_probe(struct faux_device *fdev)
 {
 	int ret;