ASoC: apple: mca: Factor out mca_be_get_fe

This is a function that we also want to use from within mca_be_shutdown,
so factor it out.

Signed-off-by: Martin Povišer <povik+lin@cutebit.org>

Author: povik

sound/soc/apple/mca.c

@@ -696,30 +696,35 @@ static bool mca_be_clk_started(struct mca_cluster *cl)
 	return false;
 }
 
-static int mca_be_startup(struct snd_pcm_substream *substream,
-			  struct snd_soc_dai *dai)
+static struct snd_soc_pcm_runtime *mca_be_get_fe(struct snd_soc_pcm_runtime *be,
+						 int stream)
 {
-	struct snd_soc_pcm_runtime *be = snd_soc_substream_to_rtd(substream);
-	struct snd_soc_pcm_runtime *fe;
-	struct mca_cluster *cl = mca_dai_to_cluster(dai);
-	struct mca_cluster *fe_cl;
-	struct mca_data *mca = cl->host;
+	struct snd_soc_pcm_runtime *fe = NULL;
 	struct snd_soc_dpcm *dpcm;
 
-	fe = NULL;
-
-	for_each_dpcm_fe(be, substream->stream, dpcm) {
+	for_each_dpcm_fe(be, stream, dpcm) {
 		if (fe && dpcm->fe != fe) {
-			dev_err(mca->dev, "many FE per one BE unsupported\n");
-			return -EINVAL;
+			dev_err(be->dev, "many FE per one BE unsupported\n");
+			return NULL;
 		}
 
 		fe = dpcm->fe;
 	}
 
+	return fe;
+}
+
+static int mca_be_startup(struct snd_pcm_substream *substream,
+			  struct snd_soc_dai *dai)
+{
+	struct snd_soc_pcm_runtime *be = snd_soc_substream_to_rtd(substream);
+	struct snd_soc_pcm_runtime *fe = mca_be_get_fe(be, substream->stream);
+	struct mca_cluster *cl = mca_dai_to_cluster(dai);
+	struct mca_cluster *fe_cl;
+	struct mca_data *mca = cl->host;
+
 	if (!fe)
 		return -EINVAL;
-
 	fe_cl = mca_dai_to_cluster(snd_soc_rtd_to_cpu(fe, 0));
 
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {