[alsa-devel] [PATCH 1/2] ASoC: soc-pcm: Allow to specify unidirectional dai_link

[Fabio Estevam]

Add 'playback_only' and 'capture_only' fields that can be used for specifying
that a dai_link has a unidirectional capability.

The motivation for this is for the cases of systems, such as Freescale MX28,
that has two unidirectional DAIs.

Signed-off-by: Fabio Estevam <fabio.estevam at freescale.com>
---
 include/sound/soc.h |  4 ++++
 sound/soc/soc-pcm.c | 10 ++++++++++
 2 files changed, 14 insertions(+)

diff --git a/include/sound/soc.h b/include/sound/soc.h
index 8e2ad52..774d3be 100644
--- a/include/sound/soc.h
+++ b/include/sound/soc.h
@@ -934,6 +934,10 @@ struct snd_soc_dai_link {
 	/* machine stream operations */
 	const struct snd_soc_ops *ops;
 	const struct snd_soc_compr_ops *compr_ops;
+
+	/* For unidirectional dai links */
+	bool playback_only;
+	bool capture_only;
 };
 
 struct snd_soc_codec_conf {
diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c
index fb70fbe..5e44863 100644
--- a/sound/soc/soc-pcm.c
+++ b/sound/soc/soc-pcm.c
@@ -2020,6 +2020,16 @@ int soc_new_pcm(struct snd_soc_pcm_runtime *rtd, int num)
 			capture = 1;
 	}
 
+	if (rtd->dai_link->playback_only) {
+		playback = 1;
+		capture = 0;
+	}
+
+	if (rtd->dai_link->capture_only) {
+		playback = 0;
+		capture = 1;
+	}
+
 	/* create the PCM */
 	if (rtd->dai_link->no_pcm) {
 		snprintf(new_name, sizeof(new_name), "(%s)",
-- 
1.8.1.2