ASoC: soc-dai: add snd_soc_dai_prepare() and use it internally

Add a new snd_soc_dai_prepare() which can be used (in an upcoming patch)
by soc-dapm.c. Use this new function internally in
snd_soc_pcm_dai_prepare() to avoid duplicating code.

Suggested-by: Jerome Brunet <[email protected]>
Reviewed-by: Charles Keepax <[email protected]>
Reviewed-by: Jerome Brunet <[email protected]>
Signed-off-by: Martin Blumenstingl <[email protected]>
Acked-by: Kuninori Morimoto <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mark Brown <[email protected]>

Author: xdarklight

include/sound/soc-dai.h

@@ -193,6 +193,9 @@ int snd_soc_dai_set_channel_map(struct snd_soc_dai *dai,
 
 int snd_soc_dai_set_tristate(struct snd_soc_dai *dai, int tristate);
 
+int snd_soc_dai_prepare(struct snd_soc_dai *dai,
+			struct snd_pcm_substream *substream);
+
 /* Digital Audio Interface mute */
 int snd_soc_dai_digital_mute(struct snd_soc_dai *dai, int mute,
 			     int direction);

sound/soc/soc-dai.c

@@ -360,6 +360,22 @@ int snd_soc_dai_set_tristate(struct snd_soc_dai *dai, int tristate)
 }
 EXPORT_SYMBOL_GPL(snd_soc_dai_set_tristate);
 
+int snd_soc_dai_prepare(struct snd_soc_dai *dai,
+			struct snd_pcm_substream *substream)
+{
+	int ret = 0;
+
+	if (!snd_soc_dai_stream_valid(dai, substream->stream))
+		return 0;
+
+	if (dai->driver->ops &&
+	    dai->driver->ops->prepare)
+		ret = dai->driver->ops->prepare(substream, dai);
+
+	return soc_dai_ret(dai, ret);
+}
+EXPORT_SYMBOL_GPL(snd_soc_dai_prepare);
+
 /**
  * snd_soc_dai_digital_mute - configure DAI system or master clock.
  * @dai: DAI
@@ -577,14 +593,9 @@ int snd_soc_pcm_dai_prepare(struct snd_pcm_substream *substream)
 	int i, ret;
 
 	for_each_rtd_dais(rtd, i, dai) {
-		if (!snd_soc_dai_stream_valid(dai, substream->stream))
-			continue;
-		if (dai->driver->ops &&
-		    dai->driver->ops->prepare) {
-			ret = dai->driver->ops->prepare(substream, dai);
-			if (ret < 0)
-				return soc_dai_ret(dai, ret);
-		}
+		ret = snd_soc_dai_prepare(dai, substream);
+		if (ret < 0)
+			return ret;
 	}
 
 	return 0;