MLK-17600: ASoC: imx-ak5558: Set MCLK as a function of fs

MCLK frequency is determined based on LRCK frequency, according
to the operation mode. Because AK5558 runs in Auto Mode, we use
table 5 from datasheet to set the correct MCLK.

Multiplier must be set twice as value shown in RM because SAI
MCLK must be at least double the BCLK.

Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
Reviewed-by: Cosmin Samoila <cosmin.samoila@nxp.com>

1 files changed, 66 insertions, 0 deletions

diff --git a/sound/soc/fsl/imx-ak5558.c b/sound/soc/fsl/imx-ak5558.c
index 2c5bfcf512b8..eb6f505df88b 100644
--- a/sound/soc/fsl/imx-ak5558.c
+++ b/sound/soc/fsl/imx-ak5558.c
@@ -10,6 +10,7 @@
  * http://www.gnu.org/copyleft/gpl.html
  */
 
+#include <linux/clk.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/slab.h>
@@ -20,12 +21,40 @@
 #include <sound/pcm.h>
 #include <sound/soc-dapm.h>
 
+#include "fsl_sai.h"
 #include "../codecs/ak5558.h"
 
 
 struct imx_ak5558_data {
 	struct snd_soc_card card;
 	bool tdm_mode;
+	unsigned long freq;
+	unsigned long slots;
+	unsigned long slot_width;
+};
+
+/*
+ * imx_ack5558_fs_mul - sampling frequency multiplier
+ *
+ * min <= fs <= max, MCLK = mul * LRCK
+ */
+struct imx_ak5558_fs_mul {
+	unsigned int min;
+	unsigned int max;
+	unsigned int mul;
+};
+
+/*
+ * Auto MCLK selection based on LRCK for Normal Mode
+ * (Table 4 from datasheet)
+ */
+static const struct imx_ak5558_fs_mul fs_mul[] = {
+	{ .min = 8000,   .max = 32000,  .mul = 1024 },
+	{ .min = 48000,  .max = 48000,  .mul = 512  },
+	{ .min = 96000,  .max = 96000,  .mul = 256  },
+	{ .min = 192000, .max = 192000, .mul = 128  },
+	{ .min = 384000, .max = 384000, .mul = 64  },
+	{ .min = 768000, .max = 768000, .mul = 32   },
 };
 
 static struct snd_soc_dapm_widget imx_ak5558_dapm_widgets[] = {
@@ -47,6 +76,25 @@ static const u32 ak5558_channels[] = {
 	1, 2, 4, 6, 8,
 };
 
+static unsigned long ak5558_get_mclk_rate(struct snd_pcm_substream *substream,
+					  struct snd_pcm_hw_params *params)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct imx_ak5558_data *data = snd_soc_card_get_drvdata(rtd->card);
+	unsigned int rate = params_rate(params);
+	unsigned int freq = data->freq;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(fs_mul); i++) {
+		if (rate < fs_mul[i].min || rate > fs_mul[i].max)
+			continue;
+		freq = rate * fs_mul[i].mul;
+		break;
+	}
+
+	return freq;
+}
+
 static int imx_aif_hw_params(struct snd_pcm_substream *substream,
 				struct snd_pcm_hw_params *params)
 {
@@ -57,6 +105,7 @@ static int imx_aif_hw_params(struct snd_pcm_substream *substream,
 	struct device *dev = card->dev;
 	struct imx_ak5558_data *data = snd_soc_card_get_drvdata(card);
 	unsigned int channels = params_channels(params);
+	unsigned long mclk_freq;
 	unsigned int fmt;
 	int ret;
 
@@ -105,6 +154,13 @@ static int imx_aif_hw_params(struct snd_pcm_substream *substream,
 		}
 	}
 
+	mclk_freq = ak5558_get_mclk_rate(substream, params);
+	ret = snd_soc_dai_set_sysclk(cpu_dai, FSL_SAI_CLK_MAST1, mclk_freq,
+				     SND_SOC_CLOCK_OUT);
+	if (ret < 0)
+		dev_err(dev, "failed to set cpu_dai mclk1 rate %lu\n",
+			mclk_freq);
+
 	return ret;
 }
 
@@ -160,6 +216,7 @@ static int imx_ak5558_probe(struct platform_device *pdev)
 	struct imx_ak5558_data *priv;
 	struct device_node *cpu_np, *codec_np = NULL;
 	struct platform_device *cpu_pdev;
+	struct clk *mclk;
 	int ret;
 
 
@@ -203,6 +260,15 @@ static int imx_ak5558_probe(struct platform_device *pdev)
 	priv->card.dapm_widgets = imx_ak5558_dapm_widgets;
 	priv->card.num_dapm_widgets = ARRAY_SIZE(imx_ak5558_dapm_widgets);
 
+	mclk = devm_clk_get(&cpu_pdev->dev, "mclk1");
+	if (IS_ERR(mclk)) {
+		ret = PTR_ERR(mclk);
+		dev_err(&pdev->dev, "failed to get DAI mclk1: %d\n", ret);
+		return -EINVAL;
+	}
+
+	priv->freq = clk_get_rate(mclk);
+
 	ret = snd_soc_of_parse_card_name(&priv->card, "model");
 	if (ret)
 		goto fail;