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 <[email protected]>
---
v1->v2:
s/factor/fs/g
---
 .../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..34d1b845edcc 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-fs            : 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..e5a3be97096c 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_fs;
        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_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 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-fs",
+                            &priv->mclk_fs);
+
        /* card name is created from CPU/CODEC dai name */
        dai_link = priv->snd_card.dai_link;
        if (!priv->snd_card.name)
-- 
2.0.0.rc0

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