PCM devices are created for FE dai links with 'no-pcm' flag as '0'.
Such DAI links have CPU component which implement either pcm_construct()
or pcm_new() at component or dai level respectively. Based on this,
current patch exposes a helper function to identify such components
and populate 'no_pcm' flag for DPCM DAI link.
This helps to have BE<->BE component links where PCM devices need
not be created for CPU component involved in such links.
Signed-off-by: Sameer Pujar <spu...@nvidia.com>
---
sound/soc/generic/audio-graph-card.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/sound/soc/generic/audio-graph-card.c
b/sound/soc/generic/audio-graph-card.c
index 1e20562..93bddf6 100644
--- a/sound/soc/generic/audio-graph-card.c
+++ b/sound/soc/generic/audio-graph-card.c
@@ -111,6 +111,17 @@ static int graph_get_dai_id(struct device_node *ep)
return id;
}
+static bool soc_component_is_pcm(struct snd_soc_dai_link_component *dlc)
+{
+ struct snd_soc_dai *dai = snd_soc_find_dai(dlc);
+
+ if (dai && (dai->component->driver->pcm_construct ||
+ dai->driver->pcm_new))
+ return true;
+
+ return false;
+}
+
static int asoc_simple_parse_dai(struct device_node *ep,
struct snd_soc_dai_link_component *dlc,
int *is_single_link)
@@ -259,6 +270,16 @@ static int graph_dai_link_of_dpcm(struct asoc_simple_priv
*priv,
if (ret < 0)
goto out_put_node;
+ /*
+ * In BE<->BE connections it is not required to create
+ * PCM devices at CPU end of the dai link and thus 'no_pcm'
+ * flag needs to be set. It is useful when there are many
+ * BE components and some of these have to be connected to
+ * form a valid audio path.
+ */
+ if (!soc_component_is_pcm(cpus))
+ dai_link->no_pcm = 1;
+
/* card->num_links includes Codec */
asoc_simple_canonicalize_cpu(dai_link, is_single_links);
} else {
--
2.7.4
