ASoC: rt5514: Add the MCLK handling

The patch adds the control of MCLK that depends on the status of DAPM.
Signed-off-by: NOder Chiou <oder_chiou@realtek.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/rt5514.txt

@@ -8,6 +8,11 @@ Required properties:
 
 - reg : The I2C address of the device.
 
+Optional properties:
+
+- clocks: The phandle of the master clock to the CODEC
+- clock-names: Should be "mclk"
+
 Pins on the device (for linking into audio routes) for RT5514:
 
   * DMIC1L

sound/soc/codecs/rt5514.c

@@ -799,10 +799,41 @@ static int rt5514_set_tdm_slot(struct snd_soc_dai *dai, unsigned int tx_mask,
 	return 0;
 }
 
+static int rt5514_set_bias_level(struct snd_soc_codec *codec,
+			enum snd_soc_bias_level level)
+{
+	struct rt5514_priv *rt5514 = snd_soc_codec_get_drvdata(codec);
+	int ret;
+
+	switch (level) {
+	case SND_SOC_BIAS_PREPARE:
+		if (IS_ERR(rt5514->mclk))
+			break;
+
+		if (snd_soc_codec_get_bias_level(codec) == SND_SOC_BIAS_ON) {
+			clk_disable_unprepare(rt5514->mclk);
+		} else {
+			ret = clk_prepare_enable(rt5514->mclk);
+			if (ret)
+				return ret;
+		}
+		break;
+
+	default:
+		break;
+	}
+
+	return 0;
+}
+
 static int rt5514_probe(struct snd_soc_codec *codec)
 {
 	struct rt5514_priv *rt5514 = snd_soc_codec_get_drvdata(codec);
 
+	rt5514->mclk = devm_clk_get(codec->dev, "mclk");
+	if (PTR_ERR(rt5514->mclk) == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+
 	rt5514->codec = codec;
 
 	return 0;
@@ -858,6 +889,7 @@ struct snd_soc_dai_driver rt5514_dai[] = {
 static struct snd_soc_codec_driver soc_codec_dev_rt5514 = {
 	.probe = rt5514_probe,
 	.idle_bias_off = true,
+	.set_bias_level = rt5514_set_bias_level,
 	.controls = rt5514_snd_controls,
 	.num_controls = ARRAY_SIZE(rt5514_snd_controls),
 	.dapm_widgets = rt5514_dapm_widgets,

sound/soc/codecs/rt5514.h

@@ -12,6 +12,8 @@
 #ifndef __RT5514_H__
 #define __RT5514_H__
 
+#include <linux/clk.h>
+
 #define RT5514_DEVICE_ID			0x10ec5514
 
 #define RT5514_RESET				0x2000
@@ -240,6 +242,7 @@ enum {
 struct rt5514_priv {
 	struct snd_soc_codec *codec;
 	struct regmap *i2c_regmap, *regmap;
+	struct clk *mclk;
 	int sysclk;
 	int sysclk_src;
 	int lrck;