ASoC: rt5640: add master clock handling for rt5640

enable/disable master clock when codec is active or not.

Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

3 files changed, 36 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/sound/rt5640.txt b/Documentation/devicetree/bindings/sound/rt5640.txt
index 9e62f6eb348f..57fe64643050 100644
--- a/Documentation/devicetree/bindings/sound/rt5640.txt
+++ b/Documentation/devicetree/bindings/sound/rt5640.txt
@@ -12,6 +12,9 @@ Required properties:
 
 Optional properties:
 
+- clocks: The phandle of the master clock to the CODEC
+- clock-names: Should be "mclk"
+
 - realtek,in1-differential
 - realtek,in2-differential
 - realtek,in3-differential
diff --git a/sound/soc/codecs/rt5640.c b/sound/soc/codecs/rt5640.c
index 11d032cdc658..6cd84fb2196a 100644
--- a/sound/soc/codecs/rt5640.c
+++ b/sound/soc/codecs/rt5640.c
@@ -1949,7 +1949,33 @@ static int rt5640_set_dai_pll(struct snd_soc_dai *dai, int pll_id, int source,
 static int rt5640_set_bias_level(struct snd_soc_codec *codec,
                         enum snd_soc_bias_level level)
 {
+        struct rt5640_priv *rt5640 = snd_soc_codec_get_drvdata(codec);
+        int ret;
+
         switch (level) {
+        case SND_SOC_BIAS_ON:
+                break;
+
+        case SND_SOC_BIAS_PREPARE:
+                /*
+                 * SND_SOC_BIAS_PREPARE is called while preparing for a
+                 * transition to ON or away from ON. If current bias_level
+                 * is SND_SOC_BIAS_ON, then it is preparing for a transition
+                 * away from ON. Disable the clock in that case, otherwise
+                 * enable it.
+                 */
+                if (IS_ERR(rt5640->mclk))
+                        break;
+
+                if (snd_soc_codec_get_bias_level(codec) == SND_SOC_BIAS_ON) {
+                        clk_disable_unprepare(rt5640->mclk);
+                } else {
+                        ret = clk_prepare_enable(rt5640->mclk);
+                        if (ret)
+                                return ret;
+                }
+                break;
+
         case SND_SOC_BIAS_STANDBY:
                 if (SND_SOC_BIAS_OFF == snd_soc_codec_get_bias_level(codec)) {
                         snd_soc_update_bits(codec, RT5640_PWR_ANLG1,
@@ -2088,6 +2114,11 @@ static int rt5640_probe(struct snd_soc_codec *codec)
         struct snd_soc_dapm_context *dapm = snd_soc_codec_get_dapm(codec);
         struct rt5640_priv *rt5640 = snd_soc_codec_get_drvdata(codec);
 
+        /* Check if MCLK provided */
+        rt5640->mclk = devm_clk_get(codec->dev, "mclk");
+        if (PTR_ERR(rt5640->mclk) == -EPROBE_DEFER)
+                return -EPROBE_DEFER;
+
         rt5640->codec = codec;
 
         snd_soc_codec_force_bias_level(codec, SND_SOC_BIAS_OFF);
diff --git a/sound/soc/codecs/rt5640.h b/sound/soc/codecs/rt5640.h
index 83a7150ddc24..1761c3a98b76 100644
--- a/sound/soc/codecs/rt5640.h
+++ b/sound/soc/codecs/rt5640.h
@@ -12,6 +12,7 @@
 #ifndef _RT5640_H
 #define _RT5640_H
 
+#include <linux/clk.h>
 #include <sound/rt5640.h>
 
 /* Info */
@@ -2097,6 +2098,7 @@ struct rt5640_priv {
         struct snd_soc_codec *codec;
         struct rt5640_platform_data pdata;
         struct regmap *regmap;
+        struct clk *mclk;
 
         int sysclk;
         int sysclk_src;