ASoC: atmel-pdmic: add the Pulse Density Modulation Interface Controller

Add driver for the Pulse Density Modulation Interface
Controller. It comes with digitallly controlled gain,
a High-Pass and a SINCC filter.

Signed-off-by: Songjun Wu <songjun.wu@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

4 files changed, 829 insertions, 0 deletions

diff --git a/sound/soc/atmel/Kconfig b/sound/soc/atmel/Kconfig
index 2d30464b81ce..06e099e802df 100644
--- a/sound/soc/atmel/Kconfig
+++ b/sound/soc/atmel/Kconfig
@@ -68,4 +68,13 @@ config SND_ATMEL_SOC_CLASSD
 	help
 	  Say Y if you want to add support for Atmel ASoC driver for boards using
 	  CLASSD.
+
+config SND_ATMEL_SOC_PDMIC
+	tristate "Atmel ASoC driver for boards using PDMIC"
+	depends on OF && (ARCH_AT91 || COMPILE_TEST)
+	select SND_SOC_GENERIC_DMAENGINE_PCM
+	select REGMAP_MMIO
+	help
+	  Say Y if you want to add support for Atmel ASoC driver for boards using
+	  PDMIC.
 endif
diff --git a/sound/soc/atmel/Makefile b/sound/soc/atmel/Makefile
index f6f7db428216..a2b127bd9c87 100644
--- a/sound/soc/atmel/Makefile
+++ b/sound/soc/atmel/Makefile
@@ -12,8 +12,10 @@ snd-soc-sam9g20-wm8731-objs := sam9g20_wm8731.o
 snd-atmel-soc-wm8904-objs := atmel_wm8904.o
 snd-soc-sam9x5-wm8731-objs := sam9x5_wm8731.o
 snd-atmel-soc-classd-objs := atmel-classd.o
+snd-atmel-soc-pdmic-objs := atmel-pdmic.o
 
 obj-$(CONFIG_SND_AT91_SOC_SAM9G20_WM8731) += snd-soc-sam9g20-wm8731.o
 obj-$(CONFIG_SND_ATMEL_SOC_WM8904) += snd-atmel-soc-wm8904.o
 obj-$(CONFIG_SND_AT91_SOC_SAM9X5_WM8731) += snd-soc-sam9x5-wm8731.o
 obj-$(CONFIG_SND_ATMEL_SOC_CLASSD) += snd-atmel-soc-classd.o
+obj-$(CONFIG_SND_ATMEL_SOC_PDMIC) += snd-atmel-soc-pdmic.o
diff --git a/sound/soc/atmel/atmel-pdmic.c b/sound/soc/atmel/atmel-pdmic.c
new file mode 100644
index 000000000000..aee4787a0b89
--- /dev/null
+++ b/sound/soc/atmel/atmel-pdmic.c
@@ -0,0 +1,738 @@
+/* Atmel PDMIC driver
+ *
+ * Copyright (C) 2015 Atmel
+ *
+ * Author: Songjun Wu <songjun.wu@atmel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 or later
+ * as published by the Free Software Foundation.
+ */
+
+#include <linux/of.h>
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <sound/core.h>
+#include <sound/dmaengine_pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/tlv.h>
+#include "atmel-pdmic.h"
+
+struct atmel_pdmic_pdata {
+	u32 mic_min_freq;
+	u32 mic_max_freq;
+	s32 mic_offset;
+	const char *card_name;
+};
+
+struct atmel_pdmic {
+	dma_addr_t phy_base;
+	struct regmap *regmap;
+	struct clk *pclk;
+	struct clk *gclk;
+	int irq;
+	struct snd_pcm_substream *substream;
+	const struct atmel_pdmic_pdata *pdata;
+};
+
+static const struct of_device_id atmel_pdmic_of_match[] = {
+	{
+		.compatible = "atmel,sama5d2-pdmic",
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(of, atmel_pdmic_of_match);
+
+#define PDMIC_OFFSET_MAX_VAL	S16_MAX
+#define PDMIC_OFFSET_MIN_VAL	S16_MIN
+
+static struct atmel_pdmic_pdata *atmel_pdmic_dt_init(struct device *dev)
+{
+	struct device_node *np = dev->of_node;
+	struct atmel_pdmic_pdata *pdata;
+
+	if (!np) {
+		dev_err(dev, "device node not found\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return ERR_PTR(-ENOMEM);
+
+	if (of_property_read_string(np, "atmel,model", &pdata->card_name))
+		pdata->card_name = "PDMIC";
+
+	if (of_property_read_u32(np, "atmel,mic-min-freq",
+				 &pdata->mic_min_freq)) {
+		dev_err(dev, "failed to get mic-min-freq\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (of_property_read_u32(np, "atmel,mic-max-freq",
+				 &pdata->mic_max_freq)) {
+		dev_err(dev, "failed to get mic-max-freq\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (pdata->mic_max_freq < pdata->mic_min_freq) {
+		dev_err(dev,
+			"mic-max-freq should not less than mic-min-freq\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (of_property_read_s32(np, "atmel,mic-offset", &pdata->mic_offset))
+		pdata->mic_offset = 0;
+
+	if (pdata->mic_offset > PDMIC_OFFSET_MAX_VAL) {
+		dev_warn(dev,
+			 "mic-offset value %d is larger than the max value %d, the max value is specified\n",
+			 pdata->mic_offset, PDMIC_OFFSET_MAX_VAL);
+		pdata->mic_offset = PDMIC_OFFSET_MAX_VAL;
+	} else if (pdata->mic_offset < PDMIC_OFFSET_MIN_VAL) {
+		dev_warn(dev,
+			 "mic-offset value %d is less than the min value %d, the min value is specified\n",
+			 pdata->mic_offset, PDMIC_OFFSET_MIN_VAL);
+		pdata->mic_offset = PDMIC_OFFSET_MIN_VAL;
+	}
+
+	return pdata;
+}
+
+/* cpu dai component */
+static int atmel_pdmic_cpu_dai_startup(struct snd_pcm_substream *substream,
+					struct snd_soc_dai *cpu_dai)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct atmel_pdmic *dd = snd_soc_card_get_drvdata(rtd->card);
+	int ret;
+
+	ret = clk_prepare_enable(dd->gclk);
+	if (ret)
+		return ret;
+
+	ret =  clk_prepare_enable(dd->pclk);
+	if (ret)
+		return ret;
+
+	/* Clear all bits in the Control Register(PDMIC_CR) */
+	regmap_write(dd->regmap, PDMIC_CR, 0);
+
+	dd->substream = substream;
+
+	/* Enable the overrun error interrupt */
+	regmap_write(dd->regmap, PDMIC_IER, PDMIC_IER_OVRE);
+
+	return 0;
+}
+
+static void atmel_pdmic_cpu_dai_shutdown(struct snd_pcm_substream *substream,
+					struct snd_soc_dai *cpu_dai)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct atmel_pdmic *dd = snd_soc_card_get_drvdata(rtd->card);
+
+	/* Disable the overrun error interrupt */
+	regmap_write(dd->regmap, PDMIC_IDR, PDMIC_IDR_OVRE);
+
+	clk_disable_unprepare(dd->gclk);
+	clk_disable_unprepare(dd->pclk);
+}
+
+static int atmel_pdmic_cpu_dai_prepare(struct snd_pcm_substream *substream,
+					struct snd_soc_dai *cpu_dai)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct atmel_pdmic *dd = snd_soc_card_get_drvdata(rtd->card);
+	u32 val;
+
+	/* Clean the PDMIC Converted Data Register */
+	return regmap_read(dd->regmap, PDMIC_CDR, &val);
+}
+
+static const struct snd_soc_dai_ops atmel_pdmic_cpu_dai_ops = {
+	.startup	= atmel_pdmic_cpu_dai_startup,
+	.shutdown	= atmel_pdmic_cpu_dai_shutdown,
+	.prepare	= atmel_pdmic_cpu_dai_prepare,
+};
+
+#define ATMEL_PDMIC_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S32_LE)
+
+static struct snd_soc_dai_driver atmel_pdmic_cpu_dai = {
+	.capture = {
+		.channels_min	= 1,
+		.channels_max	= 1,
+		.rates		= SNDRV_PCM_RATE_KNOT,
+		.formats	= ATMEL_PDMIC_FORMATS,},
+	.ops = &atmel_pdmic_cpu_dai_ops,
+};
+
+static const struct snd_soc_component_driver atmel_pdmic_cpu_dai_component = {
+	.name = "atmel-pdmic",
+};
+
+/* platform */
+#define ATMEL_PDMIC_MAX_BUF_SIZE  (64 * 1024)
+#define ATMEL_PDMIC_PREALLOC_BUF_SIZE  ATMEL_PDMIC_MAX_BUF_SIZE
+
+static const struct snd_pcm_hardware atmel_pdmic_hw = {
+	.info			= SNDRV_PCM_INFO_MMAP
+				| SNDRV_PCM_INFO_MMAP_VALID
+				| SNDRV_PCM_INFO_INTERLEAVED
+				| SNDRV_PCM_INFO_RESUME
+				| SNDRV_PCM_INFO_PAUSE,
+	.formats		= ATMEL_PDMIC_FORMATS,
+	.buffer_bytes_max	= ATMEL_PDMIC_MAX_BUF_SIZE,
+	.period_bytes_min	= 256,
+	.period_bytes_max	= 32 * 1024,
+	.periods_min		= 2,
+	.periods_max		= 256,
+};
+
+static int
+atmel_pdmic_platform_configure_dma(struct snd_pcm_substream *substream,
+				struct snd_pcm_hw_params *params,
+				struct dma_slave_config *slave_config)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct atmel_pdmic *dd = snd_soc_card_get_drvdata(rtd->card);
+	int ret;
+
+	ret = snd_hwparams_to_dma_slave_config(substream, params,
+					       slave_config);
+	if (ret) {
+		dev_err(rtd->platform->dev,
+			"hw params to dma slave configure failed\n");
+		return ret;
+	}
+
+	slave_config->src_addr		= dd->phy_base + PDMIC_CDR;
+	slave_config->src_maxburst	= 1;
+	slave_config->dst_maxburst	= 1;
+
+	return 0;
+}
+
+static const struct snd_dmaengine_pcm_config
+atmel_pdmic_dmaengine_pcm_config = {
+	.prepare_slave_config	= atmel_pdmic_platform_configure_dma,
+	.pcm_hardware		= &atmel_pdmic_hw,
+	.prealloc_buffer_size	= ATMEL_PDMIC_PREALLOC_BUF_SIZE,
+};
+
+/* codec */
+/* Mic Gain = dgain * 2^(-scale) */
+struct mic_gain {
+	unsigned int dgain;
+	unsigned int scale;
+};
+
+/* range from -90 dB to 90 dB */
+static const struct mic_gain mic_gain_table[] = {
+{    1, 15}, {    1, 14},                           /* -90, -84 dB */
+{    3, 15}, {    1, 13}, {    3, 14}, {    1, 12}, /* -81, -78, -75, -72 dB */
+{    5, 14}, {   13, 15},                           /* -70, -68 dB */
+{    9, 14}, {   21, 15}, {   23, 15}, {   13, 14}, /* -65 ~ -62 dB */
+{   29, 15}, {   33, 15}, {   37, 15}, {   41, 15}, /* -61 ~ -58 dB */
+{   23, 14}, {   13, 13}, {   58, 15}, {   65, 15}, /* -57 ~ -54 dB */
+{   73, 15}, {   41, 14}, {   23, 13}, {   13, 12}, /* -53 ~ -50 dB */
+{   29, 13}, {   65, 14}, {   73, 14}, {   41, 13}, /* -49 ~ -46 dB */
+{   23, 12}, {  207, 15}, {   29, 12}, {   65, 13}, /* -45 ~ -42 dB */
+{   73, 13}, {   41, 12}, {   23, 11}, {  413, 15}, /* -41 ~ -38 dB */
+{  463, 15}, {  519, 15}, {  583, 15}, {  327, 14}, /* -37 ~ -34 dB */
+{  367, 14}, {  823, 15}, {  231, 13}, { 1036, 15}, /* -33 ~ -30 dB */
+{ 1163, 15}, { 1305, 15}, {  183, 12}, { 1642, 15}, /* -29 ~ -26 dB */
+{ 1843, 15}, { 2068, 15}, {  145, 11}, { 2603, 15}, /* -25 ~ -22 dB */
+{  365, 12}, { 3277, 15}, { 3677, 15}, { 4125, 15}, /* -21 ~ -18 dB */
+{ 4629, 15}, { 5193, 15}, { 5827, 15}, { 3269, 14}, /* -17 ~ -14 dB */
+{  917, 12}, { 8231, 15}, { 9235, 15}, { 5181, 14}, /* -13 ~ -10 dB */
+{11627, 15}, {13045, 15}, {14637, 15}, {16423, 15}, /*  -9 ~ -6 dB */
+{18427, 15}, {20675, 15}, { 5799, 13}, {26029, 15}, /*  -5 ~ -2 dB */
+{ 7301, 13}, {    1,  0}, {18383, 14}, {10313, 13}, /*  -1 ~ 2 dB */
+{23143, 14}, {25967, 14}, {29135, 14}, {16345, 13}, /*   3 ~ 6 dB */
+{ 4585, 11}, {20577, 13}, { 1443,  9}, {25905, 13}, /*   7 ~ 10 dB */
+{14533, 12}, { 8153, 11}, { 2287,  9}, {20529, 12}, /*  11 ~ 14 dB */
+{11517, 11}, { 6461, 10}, {28997, 12}, { 4067,  9}, /*  15 ~ 18 dB */
+{18253, 11}, {   10,  0}, {22979, 11}, {25783, 11}, /*  19 ~ 22 dB */
+{28929, 11}, {32459, 11}, { 9105,  9}, {20431, 10}, /*  23 ~ 26 dB */
+{22925, 10}, {12861,  9}, { 7215,  8}, {16191,  9}, /*  27 ~ 30 dB */
+{ 9083,  8}, {20383,  9}, {11435,  8}, { 6145,  7}, /*  31 ~ 34 dB */
+{ 3599,  6}, {32305,  9}, {18123,  8}, {20335,  8}, /*  35 ~ 38 dB */
+{  713,  3}, {  100,  0}, { 7181,  6}, { 8057,  6}, /*  39 ~ 42 dB */
+{  565,  2}, {20287,  7}, {11381,  6}, {25539,  7}, /*  43 ~ 46 dB */
+{ 1791,  3}, { 4019,  4}, { 9019,  5}, {20239,  6}, /*  47 ~ 50 dB */
+{ 5677,  4}, {25479,  6}, { 7147,  4}, { 8019,  4}, /*  51 ~ 54 dB */
+{17995,  5}, {20191,  5}, {11327,  4}, {12709,  4}, /*  55 ~ 58 dB */
+{ 3565,  2}, { 1000,  0}, { 1122,  0}, { 1259,  0}, /*  59 ~ 62 dB */
+{ 2825,  1}, {12679,  3}, { 7113,  2}, { 7981,  2}, /*  63 ~ 66 dB */
+{ 8955,  2}, {20095,  3}, {22547,  3}, {12649,  2}, /*  67 ~ 70 dB */
+{28385,  3}, { 3981,  0}, {17867,  2}, {20047,  2}, /*  71 ~ 74 dB */
+{11247,  1}, {12619,  1}, {14159,  1}, {31773,  2}, /*  75 ~ 78 dB */
+{17825,  1}, {10000,  0}, {11220,  0}, {12589,  0}, /*  79 ~ 82 dB */
+{28251,  1}, {15849,  0}, {17783,  0}, {19953,  0}, /*  83 ~ 86 dB */
+{22387,  0}, {25119,  0}, {28184,  0}, {31623,  0}, /*  87 ~ 90 dB */
+};
+
+static const DECLARE_TLV_DB_RANGE(mic_gain_tlv,
+	0, 1, TLV_DB_SCALE_ITEM(-9000, 600, 0),
+	2, 5, TLV_DB_SCALE_ITEM(-8100, 300, 0),
+	6, 7, TLV_DB_SCALE_ITEM(-7000, 200, 0),
+	8, ARRAY_SIZE(mic_gain_table)-1, TLV_DB_SCALE_ITEM(-6500, 100, 0),
+);
+
+int pdmic_get_mic_volsw(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_codec *codec = snd_soc_kcontrol_codec(kcontrol);
+	unsigned int dgain_val, scale_val;
+	int i;
+
+	dgain_val = (snd_soc_read(codec, PDMIC_DSPR1) & PDMIC_DSPR1_DGAIN_MASK)
+		    >> PDMIC_DSPR1_DGAIN_SHIFT;
+
+	scale_val = (snd_soc_read(codec, PDMIC_DSPR0) & PDMIC_DSPR0_SCALE_MASK)
+		    >> PDMIC_DSPR0_SCALE_SHIFT;
+
+	for (i = 0; i < ARRAY_SIZE(mic_gain_table); i++) {
+		if ((mic_gain_table[i].dgain == dgain_val) &&
+		    (mic_gain_table[i].scale == scale_val))
+			ucontrol->value.integer.value[0] = i;
+	}
+
+	return 0;
+}
+
+static int pdmic_put_mic_volsw(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_value *ucontrol)
+{
+	struct soc_mixer_control *mc =
+		(struct soc_mixer_control *)kcontrol->private_value;
+	struct snd_soc_codec *codec = snd_soc_kcontrol_codec(kcontrol);
+	int max = mc->max;
+	unsigned int val;
+	int ret;
+
+	val = ucontrol->value.integer.value[0];
+
+	if (val > max)
+		return -EINVAL;
+
+	ret = snd_soc_update_bits(codec, PDMIC_DSPR1, PDMIC_DSPR1_DGAIN_MASK,
+			 mic_gain_table[val].dgain << PDMIC_DSPR1_DGAIN_SHIFT);
+	if (ret < 0)
+		return ret;
+
+	ret = snd_soc_update_bits(codec, PDMIC_DSPR0, PDMIC_DSPR0_SCALE_MASK,
+			 mic_gain_table[val].scale << PDMIC_DSPR0_SCALE_SHIFT);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static const struct snd_kcontrol_new atmel_pdmic_snd_controls[] = {
+SOC_SINGLE_EXT_TLV("Mic Capture Volume", PDMIC_DSPR1, PDMIC_DSPR1_DGAIN_SHIFT,
+		   ARRAY_SIZE(mic_gain_table)-1, 0,
+		   pdmic_get_mic_volsw, pdmic_put_mic_volsw, mic_gain_tlv),
+
+SOC_SINGLE("High Pass Filter Switch", PDMIC_DSPR0,
+	   PDMIC_DSPR0_HPFBYP_SHIFT, 1, 1),
+
+SOC_SINGLE("SINCC Filter Switch", PDMIC_DSPR0, PDMIC_DSPR0_SINBYP_SHIFT, 1, 1),
+};
+
+static int atmel_pdmic_codec_probe(struct snd_soc_codec *codec)
+{
+	struct snd_soc_card *card = snd_soc_codec_get_drvdata(codec);
+	struct atmel_pdmic *dd = snd_soc_card_get_drvdata(card);
+
+	snd_soc_update_bits(codec, PDMIC_DSPR1, PDMIC_DSPR1_OFFSET_MASK,
+		     (u32)(dd->pdata->mic_offset << PDMIC_DSPR1_OFFSET_SHIFT));
+
+	return 0;
+}
+
+static struct snd_soc_codec_driver soc_codec_dev_pdmic = {
+	.probe		= atmel_pdmic_codec_probe,
+	.controls	= atmel_pdmic_snd_controls,
+	.num_controls	= ARRAY_SIZE(atmel_pdmic_snd_controls),
+};
+
+/* codec dai component */
+#define PDMIC_MR_PRESCAL_MAX_VAL 127
+
+static int
+atmel_pdmic_codec_dai_hw_params(struct snd_pcm_substream *substream,
+			    struct snd_pcm_hw_params *params,
+			    struct snd_soc_dai *codec_dai)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct atmel_pdmic *dd = snd_soc_card_get_drvdata(rtd->card);
+	struct snd_soc_codec *codec = codec_dai->codec;
+	unsigned int rate_min = substream->runtime->hw.rate_min;
+	unsigned int rate_max = substream->runtime->hw.rate_max;
+	int fs = params_rate(params);
+	int bits = params_width(params);
+	unsigned long pclk_rate, gclk_rate;
+	unsigned int f_pdmic;
+	u32 mr_val, dspr0_val, pclk_prescal, gclk_prescal;
+
+	if (params_channels(params) != 1) {
+		dev_err(codec->dev,
+			"only supports one channel\n");
+		return -EINVAL;
+	}
+
+	if ((fs < rate_min) || (fs > rate_max)) {
+		dev_err(codec->dev,
+			"sample rate is %dHz, min rate is %dHz, max rate is %dHz\n",
+			fs, rate_min, rate_max);
+
+		return -EINVAL;
+	}
+
+	switch (bits) {
+	case 16:
+		dspr0_val = (PDMIC_DSPR0_SIZE_16_BITS
+			     << PDMIC_DSPR0_SIZE_SHIFT);
+		break;
+	case 32:
+		dspr0_val = (PDMIC_DSPR0_SIZE_32_BITS
+			     << PDMIC_DSPR0_SIZE_SHIFT);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if ((fs << 7) > (rate_max << 6)) {
+		f_pdmic = fs << 6;
+		dspr0_val |= PDMIC_DSPR0_OSR_64 << PDMIC_DSPR0_OSR_SHIFT;
+	} else {
+		f_pdmic = fs << 7;
+		dspr0_val |= PDMIC_DSPR0_OSR_128 << PDMIC_DSPR0_OSR_SHIFT;
+	}
+
+	pclk_rate = clk_get_rate(dd->pclk);
+	gclk_rate = clk_get_rate(dd->gclk);
+
+	/* PRESCAL = SELCK/(2*f_pdmic) - 1*/
+	pclk_prescal = (u32)(pclk_rate/(f_pdmic << 1)) - 1;
+	gclk_prescal = (u32)(gclk_rate/(f_pdmic << 1)) - 1;
+
+	if ((pclk_prescal > PDMIC_MR_PRESCAL_MAX_VAL) ||
+	    (gclk_rate/((gclk_prescal + 1) << 1) <
+	     pclk_rate/((pclk_prescal + 1) << 1))) {
+		mr_val = gclk_prescal << PDMIC_MR_PRESCAL_SHIFT;
+		mr_val |= PDMIC_MR_CLKS_GCK << PDMIC_MR_CLKS_SHIFT;
+	} else {
+		mr_val = pclk_prescal << PDMIC_MR_PRESCAL_SHIFT;
+		mr_val |= PDMIC_MR_CLKS_PCK << PDMIC_MR_CLKS_SHIFT;
+	}
+
+	snd_soc_update_bits(codec, PDMIC_MR,
+		PDMIC_MR_PRESCAL_MASK | PDMIC_MR_CLKS_MASK, mr_val);
+
+	snd_soc_update_bits(codec, PDMIC_DSPR0,
+		PDMIC_DSPR0_OSR_MASK | PDMIC_DSPR0_SIZE_MASK, dspr0_val);
+
+	return 0;
+}
+
+static int atmel_pdmic_codec_dai_prepare(struct snd_pcm_substream *substream,
+					struct snd_soc_dai *codec_dai)
+{
+	struct snd_soc_codec *codec = codec_dai->codec;
+
+	snd_soc_update_bits(codec, PDMIC_CR, PDMIC_CR_ENPDM_MASK,
+			    PDMIC_CR_ENPDM_DIS << PDMIC_CR_ENPDM_SHIFT);
+
+	return 0;
+}
+
+static int atmel_pdmic_codec_dai_trigger(struct snd_pcm_substream *substream,
+					int cmd, struct snd_soc_dai *codec_dai)
+{
+	struct snd_soc_codec *codec = codec_dai->codec;
+	u32 val;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		val = PDMIC_CR_ENPDM_EN << PDMIC_CR_ENPDM_SHIFT;
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		val = PDMIC_CR_ENPDM_DIS << PDMIC_CR_ENPDM_SHIFT;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	snd_soc_update_bits(codec, PDMIC_CR, PDMIC_CR_ENPDM_MASK, val);
+
+	return 0;
+}
+
+static const struct snd_soc_dai_ops atmel_pdmic_codec_dai_ops = {
+	.hw_params	= atmel_pdmic_codec_dai_hw_params,
+	.prepare	= atmel_pdmic_codec_dai_prepare,
+	.trigger	= atmel_pdmic_codec_dai_trigger,
+};
+
+#define ATMEL_PDMIC_CODEC_DAI_NAME  "atmel-pdmic-hifi"
+
+static struct snd_soc_dai_driver atmel_pdmic_codec_dai = {
+	.name = ATMEL_PDMIC_CODEC_DAI_NAME,
+	.capture = {
+		.stream_name	= "Capture",
+		.channels_min	= 1,
+		.channels_max	= 1,
+		.rates		= SNDRV_PCM_RATE_KNOT,
+		.formats	= ATMEL_PDMIC_FORMATS,
+	},
+	.ops = &atmel_pdmic_codec_dai_ops,
+};
+
+/* ASoC sound card */
+static int atmel_pdmic_asoc_card_init(struct device *dev,
+				struct snd_soc_card *card)
+{
+	struct snd_soc_dai_link *dai_link;
+	struct atmel_pdmic *dd = snd_soc_card_get_drvdata(card);
+
+	dai_link = devm_kzalloc(dev, sizeof(*dai_link), GFP_KERNEL);
+	if (!dai_link)
+		return -ENOMEM;
+
+	dai_link->name			= "PDMIC";
+	dai_link->stream_name		= "PDMIC PCM";
+	dai_link->codec_dai_name	= ATMEL_PDMIC_CODEC_DAI_NAME;
+	dai_link->cpu_dai_name		= dev_name(dev);
+	dai_link->codec_name		= dev_name(dev);
+	dai_link->platform_name		= dev_name(dev);
+
+	card->dai_link	= dai_link;
+	card->num_links	= 1;
+	card->name	= dd->pdata->card_name;
+	card->dev	= dev;
+
+	return 0;
+}
+
+static void atmel_pdmic_get_sample_rate(struct atmel_pdmic *dd,
+	unsigned int *rate_min, unsigned int *rate_max)
+{
+	u32 mic_min_freq = dd->pdata->mic_min_freq;
+	u32 mic_max_freq = dd->pdata->mic_max_freq;
+	u32 clk_max_rate = (u32)(clk_get_rate(dd->pclk) >> 1);
+	u32 clk_min_rate = (u32)(clk_get_rate(dd->gclk) >> 8);
+
+	if (mic_max_freq > clk_max_rate)
+		mic_max_freq = clk_max_rate;
+
+	if (mic_min_freq < clk_min_rate)
+		mic_min_freq = clk_min_rate;
+
+	*rate_min = DIV_ROUND_CLOSEST(mic_min_freq, 128);
+	*rate_max = mic_max_freq >> 6;
+}
+
+/* PDMIC interrupt handler */
+static irqreturn_t atmel_pdmic_interrupt(int irq, void *dev_id)
+{
+	struct atmel_pdmic *dd = (struct atmel_pdmic *)dev_id;
+	u32 pdmic_isr;
+	irqreturn_t ret = IRQ_NONE;
+
+	regmap_read(dd->regmap, PDMIC_ISR, &pdmic_isr);
+
+	if (pdmic_isr & PDMIC_ISR_OVRE) {
+		regmap_update_bits(dd->regmap, PDMIC_CR, PDMIC_CR_ENPDM_MASK,
+				   PDMIC_CR_ENPDM_DIS << PDMIC_CR_ENPDM_SHIFT);
+
+		snd_pcm_stop_xrun(dd->substream);
+
+		ret = IRQ_HANDLED;
+	}
+
+	return ret;
+}
+
+/* regmap configuration */
+#define ATMEL_PDMIC_REG_MAX    0x124
+static const struct regmap_config atmel_pdmic_regmap_config = {
+	.reg_bits	= 32,
+	.reg_stride	= 4,
+	.val_bits	= 32,
+	.max_register	= ATMEL_PDMIC_REG_MAX,
+};
+
+static int atmel_pdmic_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct atmel_pdmic *dd;
+	struct resource *res;
+	void __iomem *io_base;
+	const struct atmel_pdmic_pdata *pdata;
+	struct snd_soc_card *card;
+	unsigned int rate_min, rate_max;
+	int ret;
+
+	pdata = atmel_pdmic_dt_init(dev);
+	if (IS_ERR(pdata))
+		return PTR_ERR(pdata);
+
+	dd = devm_kzalloc(dev, sizeof(*dd), GFP_KERNEL);
+	if (!dd)
+		return -ENOMEM;
+
+	dd->pdata = pdata;
+
+	dd->irq = platform_get_irq(pdev, 0);
+	if (dd->irq < 0) {
+		ret = dd->irq;
+		dev_err(dev, "failed to could not get irq: %d\n", ret);
+		return ret;
+	}
+
+	dd->pclk = devm_clk_get(dev, "pclk");
+	if (IS_ERR(dd->pclk)) {
+		ret = PTR_ERR(dd->pclk);
+		dev_err(dev, "failed to get peripheral clock: %d\n", ret);
+		return ret;
+	}
+
+	dd->gclk = devm_clk_get(dev, "gclk");
+	if (IS_ERR(dd->gclk)) {
+		ret = PTR_ERR(dd->gclk);
+		dev_err(dev, "failed to get GCK: %d\n", ret);
+		return ret;
+	}
+
+	/* The gclk clock frequency must always be tree times
+	 * lower than the pclk clock frequency
+	 */
+	ret = clk_set_rate(dd->gclk, clk_get_rate(dd->pclk)/3);
+	if (ret) {
+		dev_err(dev, "failed to set GCK clock rate: %d\n", ret);
+		return ret;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "no memory resource\n");
+		return -ENXIO;
+	}
+
+	io_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(io_base)) {
+		ret = PTR_ERR(io_base);
+		dev_err(dev, "failed to remap register memory: %d\n", ret);
+		return ret;
+	}
+
+	dd->phy_base = res->start;
+
+	dd->regmap = devm_regmap_init_mmio(dev, io_base,
+					   &atmel_pdmic_regmap_config);
+	if (IS_ERR(dd->regmap)) {
+		ret = PTR_ERR(dd->regmap);
+		dev_err(dev, "failed to init register map: %d\n", ret);
+		return ret;
+	}
+
+	ret =  devm_request_irq(dev, dd->irq, atmel_pdmic_interrupt, 0,
+				"PDMIC", (void *)dd);
+	if (ret < 0) {
+		dev_err(dev, "can't register ISR for IRQ %u (ret=%i)\n",
+			dd->irq, ret);
+		return ret;
+	}
+
+	/* Get the minimal and maximal sample rate that micphone supports */
+	atmel_pdmic_get_sample_rate(dd, &rate_min, &rate_max);
+
+	/* register cpu dai */
+	atmel_pdmic_cpu_dai.capture.rate_min = rate_min;
+	atmel_pdmic_cpu_dai.capture.rate_max = rate_max;
+	ret = devm_snd_soc_register_component(dev,
+					      &atmel_pdmic_cpu_dai_component,
+					      &atmel_pdmic_cpu_dai, 1);
+	if (ret) {
+		dev_err(dev, "could not register CPU DAI: %d\n", ret);
+		return ret;
+	}
+
+	/* register platform */
+	ret = devm_snd_dmaengine_pcm_register(dev,
+					     &atmel_pdmic_dmaengine_pcm_config,
+					     0);
+	if (ret) {
+		dev_err(dev, "could not register platform: %d\n", ret);
+		return ret;
+	}
+
+	/* register codec and codec dai */
+	atmel_pdmic_codec_dai.capture.rate_min = rate_min;
+	atmel_pdmic_codec_dai.capture.rate_max = rate_max;
+	ret = snd_soc_register_codec(dev, &soc_codec_dev_pdmic,
+				     &atmel_pdmic_codec_dai, 1);
+	if (ret) {
+		dev_err(dev, "could not register codec: %d\n", ret);
+		return ret;
+	}
+
+	/* register sound card */
+	card = devm_kzalloc(dev, sizeof(*card), GFP_KERNEL);
+	if (!card) {
+		ret = -ENOMEM;
+		goto unregister_codec;
+	}
+
+	snd_soc_card_set_drvdata(card, dd);
+	platform_set_drvdata(pdev, card);
+
+	ret = atmel_pdmic_asoc_card_init(dev, card);
+	if (ret) {
+		dev_err(dev, "failed to init sound card: %d\n", ret);
+		goto unregister_codec;
+	}
+
+	ret = devm_snd_soc_register_card(dev, card);
+	if (ret) {
+		dev_err(dev, "failed to register sound card: %d\n", ret);
+		goto unregister_codec;
+	}
+
+	return 0;
+
+unregister_codec:
+	snd_soc_unregister_codec(dev);
+	return ret;
+}
+
+static int atmel_pdmic_remove(struct platform_device *pdev)
+{
+	snd_soc_unregister_codec(&pdev->dev);
+	return 0;
+}
+
+static struct platform_driver atmel_pdmic_driver = {
+	.driver	= {
+		.name		= "atmel-pdmic",
+		.of_match_table	= of_match_ptr(atmel_pdmic_of_match),
+		.pm		= &snd_soc_pm_ops,
+	},
+	.probe	= atmel_pdmic_probe,
+	.remove	= atmel_pdmic_remove,
+};
+module_platform_driver(atmel_pdmic_driver);
+
+MODULE_DESCRIPTION("Atmel PDMIC driver under ALSA SoC architecture");
+MODULE_AUTHOR("Songjun Wu <songjun.wu@atmel.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/sound/soc/atmel/atmel-pdmic.h b/sound/soc/atmel/atmel-pdmic.h
new file mode 100644
index 000000000000..4527ac741919
--- /dev/null
+++ b/sound/soc/atmel/atmel-pdmic.h
@@ -0,0 +1,80 @@
+#ifndef __ATMEL_PDMIC_H_
+#define __ATMEL_PDMIC_H_
+
+#include <linux/bitops.h>
+
+#define PDMIC_CR	0x00000000
+
+#define PDMIC_CR_SWRST		0x1
+#define PDMIC_CR_SWRST_MASK	BIT(0)
+#define PDMIC_CR_SWRST_SHIFT	(0)
+
+#define PDMIC_CR_ENPDM_DIS	0x0
+#define PDMIC_CR_ENPDM_EN	0x1
+#define PDMIC_CR_ENPDM_MASK	BIT(4)
+#define PDMIC_CR_ENPDM_SHIFT	(4)
+
+#define PDMIC_MR	0x00000004
+
+#define PDMIC_MR_CLKS_PCK	0x0
+#define PDMIC_MR_CLKS_GCK	0x1
+#define PDMIC_MR_CLKS_MASK	BIT(4)
+#define PDMIC_MR_CLKS_SHIFT	(4)
+
+#define PDMIC_MR_PRESCAL_MASK	GENMASK(14, 8)
+#define PDMIC_MR_PRESCAL_SHIFT	(8)
+
+#define PDMIC_CDR	0x00000014
+
+#define PDMIC_IER	0x00000018
+#define PDMIC_IER_OVRE			BIT(25)
+
+#define PDMIC_IDR	0x0000001c
+#define PDMIC_IDR_OVRE			BIT(25)
+
+#define PDMIC_IMR	0x00000020
+
+#define PDMIC_ISR	0x00000024
+#define PDMIC_ISR_OVRE			BIT(25)
+
+#define PDMIC_DSPR0	0x00000058
+
+#define PDMIC_DSPR0_HPFBYP_DIS		0x1
+#define PDMIC_DSPR0_HPFBYP_EN		0x0
+#define PDMIC_DSPR0_HPFBYP_MASK		BIT(1)
+#define PDMIC_DSPR0_HPFBYP_SHIFT	(1)
+
+#define PDMIC_DSPR0_SINBYP_DIS		0x1
+#define PDMIC_DSPR0_SINBYP_EN		0x0
+#define PDMIC_DSPR0_SINBYP_MASK		BIT(2)
+#define PDMIC_DSPR0_SINBYP_SHIFT	(2)
+
+#define PDMIC_DSPR0_SIZE_16_BITS	0x0
+#define PDMIC_DSPR0_SIZE_32_BITS	0x1
+#define PDMIC_DSPR0_SIZE_MASK		BIT(3)
+#define PDMIC_DSPR0_SIZE_SHIFT		(3)
+
+#define PDMIC_DSPR0_OSR_128		0x0
+#define PDMIC_DSPR0_OSR_64		0x1
+#define PDMIC_DSPR0_OSR_MASK		GENMASK(6, 4)
+#define PDMIC_DSPR0_OSR_SHIFT		(4)
+
+#define PDMIC_DSPR0_SCALE_MASK		GENMASK(11, 8)
+#define PDMIC_DSPR0_SCALE_SHIFT		(8)
+
+#define PDMIC_DSPR0_SHIFT_MASK		GENMASK(15, 12)
+#define PDMIC_DSPR0_SHIFT_SHIFT		(12)
+
+#define PDMIC_DSPR1	0x0000005c
+
+#define PDMIC_DSPR1_DGAIN_MASK		GENMASK(14, 0)
+#define PDMIC_DSPR1_DGAIN_SHIFT		(0)
+
+#define PDMIC_DSPR1_OFFSET_MASK		GENMASK(31, 16)
+#define PDMIC_DSPR1_OFFSET_SHIFT	(16)
+
+#define PDMIC_WPMR	0x000000e4
+
+#define PDMIC_WPSR	0x000000e8
+
+#endif