ASoC: soc-component: add snd_soc_component_prepare()

Current ALSA SoC is directly using component->driver->ops->xxx,
thus, it is deep nested, and makes code difficult to read,
and is not good for encapsulation.
This patch adds new snd_soc_component_prepare() and use it.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87d0hx5rnm.wl-kuninori.morimoto.gx@renesas.comSigned-off-by: Mark Brown <broonie@kernel.org>

include/sound/soc-component.h

@@ -343,5 +343,7 @@ int snd_soc_component_open(struct snd_soc_component *component,
 			   struct snd_pcm_substream *substream);
 int snd_soc_component_close(struct snd_soc_component *component,
 			    struct snd_pcm_substream *substream);
+int snd_soc_component_prepare(struct snd_soc_component *component,
+			      struct snd_pcm_substream *substream);
 
 #endif /* __SOC_COMPONENT_H */

sound/soc/soc-component.c

@@ -305,3 +305,13 @@ int snd_soc_component_close(struct snd_soc_component *component,
 
 	return 0;
 }
+
+int snd_soc_component_prepare(struct snd_soc_component *component,
+			      struct snd_pcm_substream *substream)
+{
+	if (component->driver->ops &&
+	    component->driver->ops->prepare)
+		return component->driver->ops->prepare(substream);
+
+	return 0;
+}

sound/soc/soc-pcm.c

@@ -785,11 +785,7 @@ static int soc_pcm_prepare(struct snd_pcm_substream *substream)
 	for_each_rtdcom(rtd, rtdcom) {
 		component = rtdcom->component;
 
-		if (!component->driver->ops ||
-		    !component->driver->ops->prepare)
-			continue;
-
-		ret = component->driver->ops->prepare(substream);
+		ret = snd_soc_component_prepare(component, substream);
 		if (ret < 0) {
 			dev_err(component->dev,
 				"ASoC: platform prepare error: %d\n", ret);