diff mbox

[7/7] ASoC: add STM32 DFSDM support

Message ID 1485189145-29576-8-git-send-email-arnaud.pouliquen@st.com (mailing list archive)
State New, archived
Headers show

Commit Message

Arnaud POULIQUEN Jan. 23, 2017, 4:32 p.m. UTC
Add driver to handle PDM microphones connected to DFSDM IP.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
---
 sound/soc/Kconfig            |   1 +
 sound/soc/Makefile           |   1 +
 sound/soc/stm/Kconfig        |  10 +
 sound/soc/stm/Makefile       |   2 +
 sound/soc/stm/stm32_adfsdm.c | 686 +++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 700 insertions(+)
 create mode 100644 sound/soc/stm/Kconfig
 create mode 100644 sound/soc/stm/Makefile
 create mode 100644 sound/soc/stm/stm32_adfsdm.c
diff mbox

Patch

diff --git a/sound/soc/Kconfig b/sound/soc/Kconfig
index 182d92e..3836ebe 100644
--- a/sound/soc/Kconfig
+++ b/sound/soc/Kconfig
@@ -63,6 +63,7 @@  source "sound/soc/sh/Kconfig"
 source "sound/soc/sirf/Kconfig"
 source "sound/soc/spear/Kconfig"
 source "sound/soc/sti/Kconfig"
+source "sound/soc/stm/Kconfig"
 source "sound/soc/sunxi/Kconfig"
 source "sound/soc/tegra/Kconfig"
 source "sound/soc/txx9/Kconfig"
diff --git a/sound/soc/Makefile b/sound/soc/Makefile
index 9a30f21..5440cf7 100644
--- a/sound/soc/Makefile
+++ b/sound/soc/Makefile
@@ -43,6 +43,7 @@  obj-$(CONFIG_SND_SOC)	+= sh/
 obj-$(CONFIG_SND_SOC)	+= sirf/
 obj-$(CONFIG_SND_SOC)	+= spear/
 obj-$(CONFIG_SND_SOC)	+= sti/
+obj-$(CONFIG_SND_SOC)	+= stm/
 obj-$(CONFIG_SND_SOC)	+= sunxi/
 obj-$(CONFIG_SND_SOC)	+= tegra/
 obj-$(CONFIG_SND_SOC)	+= txx9/
diff --git a/sound/soc/stm/Kconfig b/sound/soc/stm/Kconfig
new file mode 100644
index 0000000..79aee4e
--- /dev/null
+++ b/sound/soc/stm/Kconfig
@@ -0,0 +1,10 @@ 
+menuconfig SND_SOC_STM32_DFSDM
+	tristate "SoC Audio support for STM32 DFSDM"
+	depends on (ARCH_STM32 && OF && MFD_STM32_DFSDM) || COMPILE_TEST
+	depends on SND_SOC
+	select SND_SOC_GENERIC_DMAENGINE_PCM
+	select SND_SOC_DMIC
+	help
+	  Select this option to enable the STM32 Digital Filter
+	  for Sigma Delta Modulators (DFSDM) driver used
+	  in various STM32 series for digital microphone capture.
\ No newline at end of file
diff --git a/sound/soc/stm/Makefile b/sound/soc/stm/Makefile
new file mode 100644
index 0000000..ea90240
--- /dev/null
+++ b/sound/soc/stm/Makefile
@@ -0,0 +1,2 @@ 
+#DFSDM
+obj-$(CONFIG_SND_SOC_STM32_DFSDM) += stm32_adfsdm.o
diff --git a/sound/soc/stm/stm32_adfsdm.c b/sound/soc/stm/stm32_adfsdm.c
new file mode 100644
index 0000000..9d34bb7
--- /dev/null
+++ b/sound/soc/stm/stm32_adfsdm.c
@@ -0,0 +1,686 @@ 
+/*
+ * This file is part of STM32 DFSDM ASoC DAI driver
+ *
+ * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
+ * Authors: Arnaud Pouliquen <arnaud.pouliquen@st.com>
+ *          Olivier Moysan <olivier.moysan@st.com>
+ *
+ * License type: GPLv2
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include <sound/dmaengine_pcm.h>
+
+#include <linux/mfd/stm32-dfsdm.h>
+
+/*
+ * Set data output resolution to 23 bits max to keep 1 extra bit for sign,
+ * as filter output is symmetric +/-2^(n-1).
+ */
+#define STM32_ADFSDM_DATA_RES BIT(23)
+#define STM32_ADFSDM_MAX_RES BIT(31)
+#define STM32_ADFSDM_DATAR_DATA_MASK	GENMASK(31, 8)
+
+struct stm32_adfsdm_data {
+	unsigned int rate;	/* SNDRV_PCM_RATE value */
+	unsigned int freq;	/* frequency in Hz */
+	unsigned int fosr;	/* filter over sampling ratio */
+	unsigned int iosr;	/* integrator over sampling ratio */
+	unsigned int fast;	/* filter fast mode */
+	unsigned long res;	/* output data resolution */
+	int shift;		/* shift on data output */
+	bool h_res_found;	/* preferred resolution higher than expected */
+};
+
+static const struct stm32_adfsdm_data stm32_dfsdm_filter[] = {
+	{ .rate = SNDRV_PCM_RATE_8000,  .freq = 8000 },
+	{ .rate = SNDRV_PCM_RATE_16000, .freq = 16000 },
+	{ .rate = SNDRV_PCM_RATE_32000, .freq = 32000 },
+};
+
+static const unsigned int stm32_dfsdm_sr_val[] = {
+	8000,
+	16000,
+	32000,
+};
+
+struct stm32_adfsdm_priv {
+	struct snd_soc_dai_driver dai;
+	struct snd_dmaengine_dai_dma_data dma_data;
+	struct snd_pcm_substream *substream;
+	struct stm32_dfsdm_sinc_filter fl;
+	struct stm32_dfsdm_channel channel;
+	struct stm32_dfsdm_ch_cfg ch_cfg;
+	struct stm32_dfsdm *dfsdm;
+	struct stm32_adfsdm_data *f_param;
+	struct device *dev;
+	struct snd_pcm_hw_constraint_list rates_const;
+	unsigned long dmic_clk;
+	unsigned int input_id;
+	unsigned int fl_id;
+	unsigned int order; /* filter order */
+	int synchro;
+};
+
+static const struct snd_pcm_hardware stm32_adfsdm_pcm_hw = {
+	.info = SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
+	    SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_MMAP |
+	    SNDRV_PCM_INFO_MMAP_VALID,
+	.formats = SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S32_LE,
+
+	.rate_min = 8000,
+	.rate_max = 48000,
+
+	.channels_min = 1,
+	.channels_max = 1,
+
+	.periods_min = 2,
+	.periods_max = 48,
+
+	.period_bytes_min = 40, /* 8 khz 5 ms */
+	.period_bytes_max = 4 * PAGE_SIZE,
+	.buffer_bytes_max = 16 * PAGE_SIZE
+};
+
+static inline void stm32_adfsdm_get_param(struct stm32_adfsdm_priv *priv,
+					  unsigned int rate,
+					  struct stm32_adfsdm_data **fparam)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(stm32_dfsdm_filter); i++) {
+		if (rate == priv->f_param[i].freq) {
+			*fparam = &priv->f_param[i];
+			break;
+		}
+	}
+}
+
+static int stm32_adfsdm_compute_shift(struct stm32_adfsdm_priv *priv,
+				      struct stm32_adfsdm_data *param)
+{
+	int shift = 0;
+	u32 r = param->res;
+
+	if (!r) {
+		dev_err(priv->dev, "%s: resolution undefined\n", __func__);
+		return -EINVAL;
+	}
+
+	/*
+	 * If filter resolution is higher than data output resolution
+	 * compute right shift required to match data resolution.
+	 * Otherwise compute left shift to align MSB on data resolution.
+	 */
+	if (r >= STM32_ADFSDM_DATA_RES)
+		while ((r >> -shift) >= STM32_ADFSDM_DATA_RES)
+			shift--;
+	else
+		while ((r << shift) < STM32_ADFSDM_DATA_RES)
+			shift++;
+
+	param->shift = shift;
+	dev_dbg(priv->dev, "%s: output shift: %d\n", __func__, shift);
+
+	return 0;
+}
+
+static int stm32_adfsdm_get_best_osr(struct stm32_adfsdm_priv *priv,
+				     unsigned int decim, bool fast,
+				     struct stm32_adfsdm_data *param)
+{
+	unsigned int i, d, fosr, iosr;
+	u64 res;
+	s64 delta;
+	unsigned int m = 1;	/* multiplication factor */
+	unsigned int p = priv->order;	/* filter order (ford) */
+
+	/*
+	 * Decimation d depends on the filter order and the oversampling ratios.
+	 * ford: filter order
+	 * fosr: filter over sampling ratio
+	 * iosr: integrator over sampling ratio
+	 */
+	dev_dbg(priv->dev, "%s: decim = %d fast = %d\n", __func__, decim, fast);
+	if (priv->order == DFSDM_FASTSINC_ORDER) {
+		m = 2;
+		p = 2;
+	}
+
+	/*
+	 * Looks for filter and integrator oversampling ratios which allow
+	 * to reach 24 bits data output resolution.
+	 * Leave at once if exact resolution if reached.
+	 * Otherwise the higher resolution below 32 bits is kept.
+	 */
+	for (fosr = 1; fosr <= DFSDM_MAX_FL_OVERSAMPLING; fosr++) {
+		for (iosr = 1; iosr <= DFSDM_MAX_INT_OVERSAMPLING; iosr++) {
+			if (fast)
+				d = fosr * iosr;
+			else if (priv->order == DFSDM_FASTSINC_ORDER)
+				d = fosr * (iosr + 3) + 2;
+			else
+				d = fosr * (iosr - 1 + p) + p;
+
+			if (d > decim)
+				break;
+			else if (d != decim)
+				continue;
+			/*
+			 * Check resolution (limited to signed 32 bits)
+			 *   res <= 2^31
+			 * Sincx filters:
+			 *   res = m * fosr^p x iosr (with m=1, p=ford)
+			 * FastSinc filter
+			 *   res = m * fosr^p x iosr (with m=2, p=2)
+			 */
+			res = fosr;
+			for (i = p - 1; i > 0; i--) {
+				res = res * (u64)fosr;
+				if (res > STM32_ADFSDM_MAX_RES)
+					break;
+			}
+			if (res > STM32_ADFSDM_MAX_RES)
+				continue;
+			res = res * (u64)m * (u64)iosr;
+			if (res > STM32_ADFSDM_MAX_RES)
+				continue;
+
+			delta = res - STM32_ADFSDM_DATA_RES;
+
+			if (res >= param->res) {
+				param->res = res;
+				param->fosr = fosr;
+				param->iosr = iosr;
+				param->fast = fast;
+			}
+
+			if (!delta)
+				return 0;
+		}
+	}
+
+	if (!param->fosr)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int stm32_adfsdm_get_supported_rates(struct stm32_adfsdm_priv *priv,
+					    unsigned int *rates)
+{
+	unsigned long fs = priv->dmic_clk;
+	unsigned int i, decim;
+	int ret;
+
+	*rates = 0;
+
+	for (i = 0; i < ARRAY_SIZE(stm32_dfsdm_filter); i++) {
+		/* check that clkout_freq is compatible */
+		if ((fs % priv->f_param[i].freq) != 0)
+			continue;
+
+		decim = fs / priv->f_param[i].freq;
+
+		/*
+		 * Try to find one solution for filter and integrator
+		 * oversampling ratio with fast mode ON or OFF.
+		 * Fast mode on is the preferred solution.
+		 */
+		ret = stm32_adfsdm_get_best_osr(priv, decim, 0,
+						&priv->f_param[i]);
+		ret &= stm32_adfsdm_get_best_osr(priv, decim, 1,
+						 &priv->f_param[i]);
+		if (!ret) {
+			ret = stm32_adfsdm_compute_shift(priv,
+							 &priv->f_param[i]);
+			if (ret)
+				continue;
+
+			*rates |= 1 << i;
+			dev_dbg(priv->dev, "%s: %d rate supported\n", __func__,
+				priv->f_param[i].freq);
+		}
+	}
+
+	if (!*rates) {
+		dev_err(priv->dev, "%s: no matched rate found\n", __func__);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void stm32_dfsdm_xrun(struct stm32_dfsdm *dfsdm, int flt_id,
+			     enum stm32_dfsdm_events ev, unsigned int param,
+			     void *context)
+{
+	struct stm32_adfsdm_priv *priv = context;
+
+	snd_pcm_stream_lock(priv->substream);
+	dev_err(priv->dev, "%s:unexpected underrun\n", __func__);
+	/* Stop the player */
+	stm32_dfsdm_unregister_fl_event(priv->dfsdm, priv->fl_id,
+					DFSDM_EVENT_REG_XRUN, 0);
+	snd_pcm_stop(priv->substream, SNDRV_PCM_STATE_XRUN);
+	snd_pcm_stream_unlock(priv->substream);
+}
+
+static int stm32_adfsdm_copy(struct snd_pcm_substream *substream, int channel,
+			     snd_pcm_uframes_t pos,
+			     void __user *buf, snd_pcm_uframes_t count)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(rtd->cpu_dai);
+	struct stm32_adfsdm_data *f_param;
+	int *ptr = (int *)(runtime->dma_area + frames_to_bytes(runtime, pos));
+	char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, pos);
+	ssize_t bytes = frames_to_bytes(runtime, count);
+	ssize_t sample_cnt = bytes_to_samples(runtime, bytes);
+
+	stm32_adfsdm_get_param(priv, runtime->rate, &f_param);
+
+	/*
+	 * Audio samples are available on 24 MSBs of the DFSDM DATAR register.
+	 * We need to mask 8 LSB control bits...
+	 * Additionnaly precision depends on decimation and can need shift
+	 * to be aligned on 32-bit word MSB.
+	 */
+	if (f_param->shift > 0) {
+		do {
+			*ptr <<= f_param->shift & STM32_ADFSDM_DATAR_DATA_MASK;
+			ptr++;
+		} while (--sample_cnt);
+	} else {
+		do {
+			*ptr &= STM32_ADFSDM_DATAR_DATA_MASK;
+			ptr++;
+		} while (--sample_cnt);
+	}
+
+	return copy_to_user(buf, hwbuf, bytes);
+}
+
+static int stm32_adfsdm_startup(struct snd_pcm_substream *substream,
+				struct snd_soc_dai *dai)
+{
+	struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
+
+	priv->substream = substream;
+
+	/* Fix available rate depending on CLKOUT or CKIN value */
+	return snd_pcm_hw_constraint_list(substream->runtime, 0,
+					  SNDRV_PCM_HW_PARAM_RATE,
+					  &priv->rates_const);
+}
+
+static void stm32_adfsdm_shutdown(struct snd_pcm_substream *substream,
+				  struct snd_soc_dai *dai)
+{
+	struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
+
+	priv->substream = NULL;
+}
+
+static int stm32_adfsdm_dai_hw_params(struct snd_pcm_substream *substream,
+				      struct snd_pcm_hw_params *params,
+				      struct snd_soc_dai *dai)
+{
+	struct snd_dmaengine_dai_dma_data *dma_data;
+
+	dev_dbg(dai->dev, "%s: enter\n", __func__);
+	dma_data = snd_soc_dai_get_dma_data(dai, substream);
+	dma_data->maxburst = 1;
+
+	return 0;
+}
+
+static int stm32_adfsdm_prepare(struct snd_pcm_substream *substream,
+				struct snd_soc_dai *dai)
+{
+	struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct stm32_adfsdm_data *f_param;
+	struct stm32_dfsdm_filter filter;
+	struct stm32_dfsdm_regular params;
+	int ret;
+
+	dev_dbg(dai->dev, "%s: enter\n", __func__);
+
+	stm32_adfsdm_get_param(priv, runtime->rate, &f_param);
+
+	memset(&filter, 0, sizeof(filter));
+	memset(&params, 0, sizeof(params));
+
+	params.ch_src = priv->channel.id;
+	params.dma_mode = 1;
+	params.cont_mode = 1;
+	params.fast_mode = f_param->fast;
+	params.sync_mode = priv->synchro ?
+	    DFSDM_FILTER_RSYNC_ON : DFSDM_FILTER_RSYNC_OFF;
+	filter.reg_params = &params;
+	filter.sinc_params.order = priv->order;
+	filter.sinc_params.oversampling = f_param->fosr;
+	filter.int_oversampling = f_param->iosr;
+
+	filter.event.cb = stm32_dfsdm_xrun;
+	filter.event.context = priv;
+
+	ret = stm32_dfsdm_configure_filter(priv->dfsdm, priv->fl_id, &filter);
+	if (ret < 0)
+		return ret;
+
+	ret = stm32_dfsdm_register_fl_event(priv->dfsdm, priv->fl_id,
+					    DFSDM_EVENT_REG_XRUN, 0);
+	if (ret < 0)
+		dev_err(priv->dev, "Failed to register xrun event\n");
+
+	return ret;
+}
+
+static int stm32_adfsdm_start(struct snd_pcm_substream *substream,
+			      struct snd_soc_dai *dai)
+{
+	struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct stm32_adfsdm_data *f_param;
+	int ret;
+
+	dev_dbg(dai->dev, "%s: enter\n", __func__);
+
+	stm32_adfsdm_get_param(priv, runtime->rate, &f_param);
+	if (f_param->shift < 0)
+		priv->ch_cfg.right_bit_shift = -f_param->shift;
+
+	ret = stm32_dfsdm_start_channel(priv->dfsdm, priv->channel.id,
+					&priv->ch_cfg);
+	if (ret < 0)
+		return ret;
+
+	stm32_dfsdm_start_filter(priv->dfsdm, priv->fl_id,
+				 DFSDM_FILTER_REG_CONV);
+
+	return 0;
+}
+
+static void stm32_adfsdm_stop(struct snd_pcm_substream *substream,
+			      struct snd_soc_dai *dai)
+{
+	struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
+
+	dev_dbg(dai->dev, "%s: enter\n", __func__);
+
+	stm32_dfsdm_unregister_fl_event(priv->dfsdm, priv->fl_id,
+					DFSDM_EVENT_REG_XRUN, 0);
+	stm32_dfsdm_stop_filter(priv->dfsdm, priv->fl_id);
+	stm32_dfsdm_stop_channel(priv->dfsdm, priv->channel.id);
+}
+
+static int stm32_adfsdm_trigger(struct snd_pcm_substream *substream, int cmd,
+				struct snd_soc_dai *dai)
+{
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+		return stm32_adfsdm_start(substream, dai);
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_STOP:
+		stm32_adfsdm_stop(substream, dai);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int stm32_adfsdm_set_dai_fmt(struct snd_soc_dai *dai, unsigned int fmt)
+{
+	struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
+	unsigned int inv = fmt & SND_SOC_DAIFMT_INV_MASK;
+	unsigned int cb = fmt & SND_SOC_DAIFMT_MASTER_MASK;
+	int ret;
+
+	dev_dbg(dai->dev, "%s: enter\n", __func__);
+
+	/* DAI clock strobing */
+	if ((inv == SND_SOC_DAIFMT_IB_NF) || (inv == SND_SOC_DAIFMT_IB_IF)) {
+		priv->channel.serial_if.type = DFSDM_CHANNEL_SPI_FALLING;
+		priv->channel.serial_if.pins = DFSDM_CHANNEL_NEXT_CHANNEL_PINS;
+		/*
+		 * if data on falling egde SPI connected to channel n - 1.
+		 * if data on rising egde  SPI connected to channel n.
+		 */
+		if (priv->input_id)
+			priv->channel.id = priv->input_id - 1;
+		else
+			priv->channel.id = priv->dfsdm->max_channels - 1;
+	} else {
+		priv->channel.serial_if.type = DFSDM_CHANNEL_SPI_RISING;
+		priv->channel.serial_if.pins = DFSDM_CHANNEL_SAME_CHANNEL_PINS;
+		priv->channel.id = priv->input_id;
+	}
+
+	dev_dbg(dai->dev, "%s: channel %d on input %d\n", __func__,
+		priv->channel.id, priv->input_id);
+
+	if ((cb == SND_SOC_DAIFMT_CBS_CFM) || (cb == SND_SOC_DAIFMT_CBS_CFS)) {
+		/* Digital microphone is clocked by CLKOUT */
+		stm32_dfsdm_get_clk_out_rate(priv->dfsdm, &priv->dmic_clk);
+	} else {
+		/* Digital microphone is clocked by external clock */
+		if (!priv->dmic_clk) {
+			dev_err(priv->dev,
+				"system-clock-frequency not defined\n");
+			return -EINVAL;
+		}
+	}
+
+	priv->rates_const.count = ARRAY_SIZE(stm32_dfsdm_sr_val);
+	priv->rates_const.list = stm32_dfsdm_sr_val;
+	ret = stm32_adfsdm_get_supported_rates(priv, &priv->rates_const.mask);
+	if (ret < 0)
+		return ret;
+
+	return stm32_dfsdm_get_channel(priv->dfsdm, &priv->channel);
+}
+
+static int stm32_adfsdm_set_sysclk(struct snd_soc_dai *dai, int clk_id,
+				   unsigned int freq, int dir)
+{
+	struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
+
+	dev_dbg(dai->dev, "%s: enter for dai %d\n", __func__, dai->id);
+	if (dir == SND_SOC_CLOCK_IN)
+		priv->dmic_clk = freq;
+
+	return 0;
+}
+
+static const struct snd_soc_dai_ops stm32_adfsdm_dai_ops = {
+	.startup = stm32_adfsdm_startup,
+	.shutdown = stm32_adfsdm_shutdown,
+	.hw_params = stm32_adfsdm_dai_hw_params,
+	.set_fmt = stm32_adfsdm_set_dai_fmt,
+	.set_sysclk = stm32_adfsdm_set_sysclk,
+	.prepare = stm32_adfsdm_prepare,
+	.trigger = stm32_adfsdm_trigger,
+};
+
+static int stm32_adfsdm_dai_probe(struct snd_soc_dai *dai)
+{
+	struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
+	struct snd_dmaengine_dai_dma_data *dma = &priv->dma_data;
+	int ret;
+
+	dev_dbg(dai->dev, "%s: enter for dai %d\n", __func__, dai->id);
+
+	/* filter settings */
+	ret = stm32_dfsdm_get_filter(priv->dfsdm, priv->fl_id);
+	if (ret < 0)
+		return -EBUSY;
+
+	/* DMA settings */
+	snd_soc_dai_init_dma_data(dai, NULL, dma);
+	dma->addr = stm32_dfsdm_get_filter_dma_phy_addr(priv->dfsdm,
+							priv->fl_id,
+							DFSDM_FILTER_REG_CONV);
+	dma->addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+
+	return 0;
+}
+
+static int stm32_adfsdm_dai_remove(struct snd_soc_dai *dai)
+{
+	struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
+
+	dev_dbg(dai->dev, "%s: enter for dai %d\n", __func__, dai->id);
+
+	stm32_dfsdm_release_filter(priv->dfsdm, priv->fl_id);
+	stm32_dfsdm_release_channel(priv->dfsdm, priv->channel.id);
+
+	return 0;
+}
+
+static const struct snd_soc_dai_driver stm32_adfsdm_dai = {
+	.capture = {
+		    .channels_min = 1,
+		    .channels_max = 1,
+		    .formats = SNDRV_PCM_FMTBIT_S24_LE |
+			       SNDRV_PCM_FMTBIT_S32_LE,
+		    .rates = SNDRV_PCM_RATE_8000_48000,
+		    },
+	.probe = stm32_adfsdm_dai_probe,
+	.remove = stm32_adfsdm_dai_remove,
+	.ops = &stm32_adfsdm_dai_ops,
+};
+
+static const struct snd_soc_component_driver stm32_adfsdm_dai_component = {
+	.name = "sti_cpu_dai",
+};
+
+static const struct snd_dmaengine_pcm_config dmaengine_pcm_config = {
+	.pcm_hardware = &stm32_adfsdm_pcm_hw,
+	.prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
+	.copy = stm32_adfsdm_copy,
+};
+
+static int stm32_adfsdm_probe(struct platform_device *pdev)
+{
+	struct stm32_adfsdm_priv *priv;
+	struct device_node *np = pdev->dev.of_node;
+	char *_name;
+	int ret;
+
+	dev_dbg(&pdev->dev, "%s: enter for node %s\n", __func__,
+		np->name);
+
+	if (!np) {
+		dev_err(&pdev->dev, "No DT found\n");
+		return -EINVAL;
+	}
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->dev = &pdev->dev;
+	priv->dfsdm = dev_get_drvdata(pdev->dev.parent);
+
+	if (of_property_read_u32(np, "reg", &priv->fl_id)) {
+		dev_err(&pdev->dev, "missing reg property\n");
+		return -EINVAL;
+	}
+
+	ret = of_property_read_u32(np, "st,dai-filter-order", &priv->order);
+	if (ret < 0) {
+		dev_warn(&pdev->dev, "Default filter order selected\n");
+		priv->order = DFSDM_SINC5_ORDER;
+	}
+
+	ret = of_property_read_u32(np, "st,input-id", &priv->input_id);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "st,input-id property missing\n");
+		return ret;
+	}
+
+	ret = of_property_read_u32(np, "st,dai0-synchronized", &priv->synchro);
+	if (ret < 0)
+		/* default case if property not defined */
+		priv->synchro = 0;
+
+	priv->channel.type.DataPacking = DFSDM_CHANNEL_STANDARD_MODE;
+	priv->channel.type.source = DFSDM_CHANNEL_EXTERNAL_INPUTS;
+	priv->channel.serial_if.spi_clk = DFSDM_CHANNEL_SPI_CLOCK_INTERNAL;
+
+	/* DAI settings */
+	_name = devm_kzalloc(&pdev->dev, sizeof("dfsdm_pdm_0"), GFP_KERNEL);
+	if (!_name)
+		return -ENOMEM;
+
+	priv->dai = stm32_adfsdm_dai;
+
+	priv->f_param = devm_kcalloc(&pdev->dev,
+				     ARRAY_SIZE(stm32_dfsdm_filter),
+				     sizeof(stm32_dfsdm_filter[0]), GFP_KERNEL);
+	if (!priv->f_param)
+		return -ENOMEM;
+
+	memcpy(priv->f_param, stm32_dfsdm_filter,
+	       ARRAY_SIZE(stm32_dfsdm_filter) * sizeof(stm32_dfsdm_filter[0]));
+
+	snprintf(_name, sizeof("dfsdm_pdm_0"), "dfsdm_pdm_%i", priv->fl_id);
+	priv->dai.name = _name;
+	priv->dai.capture.stream_name = _name;
+
+	dev_set_drvdata(&pdev->dev, priv);
+
+	ret = devm_snd_soc_register_component(&pdev->dev,
+					      &stm32_adfsdm_dai_component,
+					      &priv->dai, 1);
+	if (ret < 0)
+		return ret;
+
+	ret = devm_snd_dmaengine_pcm_register(&pdev->dev,
+					      &dmaengine_pcm_config, 0);
+	if (ret < 0)
+		dev_err(&pdev->dev, "failed to register dma pcm config\n");
+
+	return ret;
+}
+
+static const struct of_device_id snd_soc_dfsdm_match[] = {
+	{.compatible = "st,stm32-dfsdm-audio"},
+	{},
+};
+
+static struct platform_driver stm32_adfsdm_driver = {
+	.driver = {
+		   .name = "stm32-dfsdm-audio",
+		   .of_match_table = snd_soc_dfsdm_match,
+		   },
+	.probe = stm32_adfsdm_probe,
+};
+
+module_platform_driver(stm32_adfsdm_driver);
+
+MODULE_DESCRIPTION("stm32 DFSDM DAI driver");
+MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
+MODULE_LICENSE("GPL v2");