Some platforms require that the codecs mclk is a fixed multiplication
factor of the audio stream rate. Add a optional property to the
binding to hold this factor and implement a hw_params() function to
make use of it.
Signed-off-by: Andrew Lunn <andrew@xxxxxxx>
---
.../devicetree/bindings/sound/simple-card.txt | 2 ++
sound/soc/generic/simple-card.c | 28 ++++++++++++++++++++++
2 files changed, 30 insertions(+)
diff --git a/Documentation/devicetree/bindings/sound/simple-card.txt b/Documentation/devicetree/bindings/sound/simple-card.txt
index 131aa2ad7f1a..c4379c9f9f03 100644
--- a/Documentation/devicetree/bindings/sound/simple-card.txt
+++ b/Documentation/devicetree/bindings/sound/simple-card.txt
@@ -18,6 +18,8 @@ Optional properties:
Each entry is a pair of strings, the first being the
connection's sink, the second being the connection's
source.
+- simple-audio-card,mclk-factor : Multiplication factor between stream rate and codec
+ mclk.
- dai-tdm-slot-num : Please refer to tdm-slot.txt.
- dai-tdm-slot-width : Please refer to tdm-slot.txt.
diff --git a/sound/soc/generic/simple-card.c b/sound/soc/generic/simple-card.c
index 21f1ccbdf582..5ecaf57ab712 100644
--- a/sound/soc/generic/simple-card.c
+++ b/sound/soc/generic/simple-card.c
@@ -24,6 +24,7 @@ struct simple_card_data {
struct asoc_simple_dai cpu_dai;
struct asoc_simple_dai codec_dai;
} *dai_props;
+ unsigned int mclk_factor;
struct snd_soc_dai_link dai_link[]; /* dynamically allocated */
};
@@ -151,6 +152,28 @@ asoc_simple_card_sub_parse_of(struct device_node *np,
return 0;
}
+static int simple_card_hw_params(struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params)
+{
+ struct snd_soc_pcm_runtime *rtd = substream->private_data;
+ struct snd_soc_dai *codec_dai = rtd->codec_dai;
+ struct simple_card_data *priv = snd_soc_card_get_drvdata(rtd->card);
+ unsigned int mclk;
+ int ret = 0;
+
+ if (priv->mclk_factor) {
+ mclk = params_rate(params) * priv->mclk_factor;
+ ret = snd_soc_dai_set_sysclk(codec_dai, 0, mclk,
+ SND_SOC_CLOCK_IN);
+ }
+
+ return ret;
+}
+
+static struct snd_soc_ops simple_card_ops = {
+ .hw_params = simple_card_hw_params,
+};
+
static int simple_card_cpu_codec_of(struct device_node *node,
int daifmt,
struct snd_soc_dai_link *dai_link,
@@ -255,6 +278,7 @@ static int asoc_simple_card_parse_of(struct device_node *node,
sprintf(name, "%s-%s", dai_link->cpu_dai_name,
dai_link->codec_dai_name);
dai_link->name = dai_link->stream_name = name;
+ dai_link->ops = &simple_card_ops;
if (!multi)
break;
@@ -263,6 +287,10 @@ static int asoc_simple_card_parse_of(struct device_node *node,
dai_props++;
}
+ /* Factor to mclk, used in hw_params() */
+ of_property_read_u32(node, "simple-audio-card,mclk-factor",
+ &priv->mclk_factor);
+
/* card name is created from CPU/CODEC dai name */
dai_link = priv->snd_card.dai_link;
if (!priv->snd_card.name)
--
1.9.2
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