ASoC: simple-card: Support setting mclk via a fixed factor

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@lunn.ch>
Signed-off-by: Mark Brown <broonie@linaro.org>

1 files changed, 28 insertions, 0 deletions

diff --git a/sound/soc/generic/simple-card.c b/sound/soc/generic/simple-card.c
index 06fe0e22b267..03a7fdcdf114 100644
--- a/sound/soc/generic/simple-card.c
+++ b/sound/soc/generic/simple-card.c
@@ -24,9 +24,32 @@ struct simple_card_data {
                 struct asoc_simple_dai cpu_dai;
                 struct asoc_simple_dai codec_dai;
         } *dai_props;
+        unsigned int mclk_fs;
         struct snd_soc_dai_link dai_link[];     /* dynamically allocated */
 };
 
+static int asoc_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_fs) {
+                mclk = params_rate(params) * priv->mclk_fs;
+                ret = snd_soc_dai_set_sysclk(codec_dai, 0, mclk,
+                                             SND_SOC_CLOCK_IN);
+        }
+
+        return ret;
+}
+
+static struct snd_soc_ops asoc_simple_card_ops = {
+        .hw_params = asoc_simple_card_hw_params,
+};
+
 static int __asoc_simple_card_dai_init(struct snd_soc_dai *dai,
                                        struct asoc_simple_dai *set)
 {
@@ -251,6 +274,7 @@ static int simple_card_dai_link_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 = &asoc_simple_card_ops;
 
         dev_dbg(dev, "\tname : %s\n", dai_link->stream_name);
         dev_dbg(dev, "\tcpu : %s / %04x / %d\n",
@@ -300,6 +324,10 @@ static int asoc_simple_card_parse_of(struct device_node *node,
                         return ret;
         }
 
+        /* Factor to mclk, used in hw_params() */
+        of_property_read_u32(node, "simple-audio-card,mclk-fs",
+                             &priv->mclk_fs);
+
         dev_dbg(dev, "New simple-card: %s\n", priv->snd_card.name ?
                 priv->snd_card.name : "");