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Unverified Commit 55da0948 authored by Arnaud Pouliquen's avatar Arnaud Pouliquen Committed by Mark Brown
Browse files

ASoC: stm32: add DFSDM DAI support 



Add driver to handle DAI interface for PDM microphones connected
to Digital Filter for Sigma Delta Modulators IP.

Signed-off-by: default avatarArnaud Pouliquen <arnaud.pouliquen@st.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent a7161579

sound/soc/stm/Kconfig

+11 −0
Original line number Diff line number Diff line
@@ -28,4 +28,15 @@ config SND_SOC_STM32_SPDIFRX 
	help

	  Say Y if you want to enable S/PDIF capture for STM32



config SND_SOC_STM32_DFSDM

	tristate "SoC Audio support for STM32 DFSDM"

	depends on (ARCH_STM32 && OF && STM32_DFSDM_ADC) || COMPILE_TEST

	depends on SND_SOC

	select SND_SOC_GENERIC_DMAENGINE_PCM

	select SND_SOC_DMIC

	select IIO_BUFFER_CB

	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.

endmenu

sound/soc/stm/Makefile

+3 −0
Original line number Diff line number Diff line
@@ -13,3 +13,6 @@ obj-$(CONFIG_SND_SOC_STM32_I2S) += snd-soc-stm32-i2s.o 
# SPDIFRX

snd-soc-stm32-spdifrx-objs := stm32_spdifrx.o

obj-$(CONFIG_SND_SOC_STM32_SPDIFRX) += snd-soc-stm32-spdifrx.o



#DFSDM

obj-$(CONFIG_SND_SOC_STM32_DFSDM) += stm32_adfsdm.o

sound/soc/stm/stm32_adfsdm.c

0 → 100644
+347 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * 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>

 */



#include <linux/clk.h>

#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/slab.h>



#include <linux/iio/iio.h>

#include <linux/iio/consumer.h>

#include <linux/iio/adc/stm32-dfsdm-adc.h>



#include <sound/pcm.h>

#include <sound/soc.h>



#define STM32_ADFSDM_DRV_NAME "stm32-adfsdm"



#define DFSDM_MAX_PERIOD_SIZE	(PAGE_SIZE / 2)

#define DFSDM_MAX_PERIODS	6



struct stm32_adfsdm_priv {

	struct snd_soc_dai_driver dai_drv;

	struct snd_pcm_substream *substream;

	struct device *dev;



	/* IIO */

	struct iio_channel *iio_ch;

	struct iio_cb_buffer *iio_cb;

	bool iio_active;



	/* PCM buffer */

	unsigned char *pcm_buff;

	unsigned int pos;

};



static const struct snd_pcm_hardware stm32_adfsdm_pcm_hw = {

	.info = SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |

	    SNDRV_PCM_INFO_PAUSE,

	.formats = SNDRV_PCM_FMTBIT_S32_LE,



	.rate_min = 8000,

	.rate_max = 32000,



	.channels_min = 1,

	.channels_max = 1,



	.periods_min = 2,

	.periods_max = DFSDM_MAX_PERIODS,



	.period_bytes_max = DFSDM_MAX_PERIOD_SIZE,

	.buffer_bytes_max = DFSDM_MAX_PERIODS * DFSDM_MAX_PERIOD_SIZE

};



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);



	if (priv->iio_active) {

		iio_channel_stop_all_cb(priv->iio_cb);

		priv->iio_active = false;

	}

}



static int stm32_adfsdm_dai_prepare(struct snd_pcm_substream *substream,

				    struct snd_soc_dai *dai)

{

	struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);

	int ret;



	ret = iio_write_channel_attribute(priv->iio_ch,

					  substream->runtime->rate, 0,

					  IIO_CHAN_INFO_SAMP_FREQ);

	if (ret < 0) {

		dev_err(dai->dev, "%s: Failed to set %d sampling rate\n",

			__func__, substream->runtime->rate);

		return ret;

	}



	if (!priv->iio_active) {

		ret = iio_channel_start_all_cb(priv->iio_cb);

		if (!ret)

			priv->iio_active = true;

		else

			dev_err(dai->dev, "%s: IIO channel start failed (%d)\n",

				__func__, ret);

	}



	return ret;

}



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);

	ssize_t size;

	char str_freq[10];



	dev_dbg(dai->dev, "%s: Enter for freq %d\n", __func__, freq);



	/* Set IIO frequency if CODEC is master as clock comes from SPI_IN */



	snprintf(str_freq, sizeof(str_freq), "%d\n", freq);

	size = iio_write_channel_ext_info(priv->iio_ch, "spi_clk_freq",

					  str_freq, sizeof(str_freq));

	if (size != sizeof(str_freq)) {

		dev_err(dai->dev, "%s: Failed to set SPI clock\n",

			__func__);

		return -EINVAL;

	}

	return 0;

}



static const struct snd_soc_dai_ops stm32_adfsdm_dai_ops = {

	.shutdown = stm32_adfsdm_shutdown,

	.prepare = stm32_adfsdm_dai_prepare,

	.set_sysclk = stm32_adfsdm_set_sysclk,

};



static const struct snd_soc_dai_driver stm32_adfsdm_dai = {

	.capture = {

		    .channels_min = 1,

		    .channels_max = 1,

		    .formats = SNDRV_PCM_FMTBIT_S32_LE,

		    .rates = (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_16000 |

			      SNDRV_PCM_RATE_32000),

		    },

	.ops = &stm32_adfsdm_dai_ops,

};



static const struct snd_soc_component_driver stm32_adfsdm_dai_component = {

	.name = "stm32_dfsdm_audio",

};



static int stm32_afsdm_pcm_cb(const void *data, size_t size, void *private)

{

	struct stm32_adfsdm_priv *priv = private;

	struct snd_soc_pcm_runtime *rtd = priv->substream->private_data;

	u8 *pcm_buff = priv->pcm_buff;

	u8 *src_buff = (u8 *)data;

	unsigned int buff_size = snd_pcm_lib_buffer_bytes(priv->substream);

	unsigned int period_size = snd_pcm_lib_period_bytes(priv->substream);

	unsigned int old_pos = priv->pos;

	unsigned int cur_size = size;



	dev_dbg(rtd->dev, "%s: buff_add :%p, pos = %d, size = %zu\n",

		__func__, &pcm_buff[priv->pos], priv->pos, size);



	if ((priv->pos + size) > buff_size) {

		memcpy(&pcm_buff[priv->pos], src_buff, buff_size - priv->pos);

		cur_size -= buff_size - priv->pos;

		priv->pos = 0;

	}



	memcpy(&pcm_buff[priv->pos], &src_buff[size - cur_size], cur_size);

	priv->pos = (priv->pos + cur_size) % buff_size;



	if (cur_size != size || (old_pos && (old_pos % period_size < size)))

		snd_pcm_period_elapsed(priv->substream);



	return 0;

}



static int stm32_adfsdm_trigger(struct snd_pcm_substream *substream, int cmd)

{

	struct snd_soc_pcm_runtime *rtd = substream->private_data;

	struct stm32_adfsdm_priv *priv =

		snd_soc_dai_get_drvdata(rtd->cpu_dai);



	switch (cmd) {

	case SNDRV_PCM_TRIGGER_START:

	case SNDRV_PCM_TRIGGER_RESUME:

		priv->pos = 0;

		return stm32_dfsdm_get_buff_cb(priv->iio_ch->indio_dev,

					       stm32_afsdm_pcm_cb, priv);

	case SNDRV_PCM_TRIGGER_SUSPEND:

	case SNDRV_PCM_TRIGGER_STOP:

		return stm32_dfsdm_release_buff_cb(priv->iio_ch->indio_dev);

	}



	return -EINVAL;

}



static int stm32_adfsdm_pcm_open(struct snd_pcm_substream *substream)

{

	struct snd_soc_pcm_runtime *rtd = substream->private_data;

	struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(rtd->cpu_dai);

	int ret;



	ret =  snd_soc_set_runtime_hwparams(substream, &stm32_adfsdm_pcm_hw);

	if (!ret)

		priv->substream = substream;



	return ret;

}



static int stm32_adfsdm_pcm_close(struct snd_pcm_substream *substream)

{

	struct snd_soc_pcm_runtime *rtd = substream->private_data;

	struct stm32_adfsdm_priv *priv =

		snd_soc_dai_get_drvdata(rtd->cpu_dai);



	snd_pcm_lib_free_pages(substream);

	priv->substream = NULL;



	return 0;

}



static snd_pcm_uframes_t stm32_adfsdm_pcm_pointer(

					    struct snd_pcm_substream *substream)

{

	struct snd_soc_pcm_runtime *rtd = substream->private_data;

	struct stm32_adfsdm_priv *priv =

		snd_soc_dai_get_drvdata(rtd->cpu_dai);



	return bytes_to_frames(substream->runtime, priv->pos);

}



static int stm32_adfsdm_pcm_hw_params(struct snd_pcm_substream *substream,

				      struct snd_pcm_hw_params *params)

{

	struct snd_soc_pcm_runtime *rtd = substream->private_data;

	struct stm32_adfsdm_priv *priv =

		snd_soc_dai_get_drvdata(rtd->cpu_dai);

	int ret;



	ret =  snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));

	if (ret < 0)

		return ret;

	priv->pcm_buff = substream->runtime->dma_area;



	return iio_channel_cb_set_buffer_watermark(priv->iio_cb,

						   params_period_size(params));

}



static int stm32_adfsdm_pcm_hw_free(struct snd_pcm_substream *substream)

{

	snd_pcm_lib_free_pages(substream);



	return 0;

}



static struct snd_pcm_ops stm32_adfsdm_pcm_ops = {

	.open		= stm32_adfsdm_pcm_open,

	.close		= stm32_adfsdm_pcm_close,

	.hw_params	= stm32_adfsdm_pcm_hw_params,

	.hw_free	= stm32_adfsdm_pcm_hw_free,

	.trigger	= stm32_adfsdm_trigger,

	.pointer	= stm32_adfsdm_pcm_pointer,

};



static int stm32_adfsdm_pcm_new(struct snd_soc_pcm_runtime *rtd)

{

	struct snd_pcm *pcm = rtd->pcm;

	struct stm32_adfsdm_priv *priv =

		snd_soc_dai_get_drvdata(rtd->cpu_dai);

	unsigned int size = DFSDM_MAX_PERIODS * DFSDM_MAX_PERIOD_SIZE;



	return snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,

						     priv->dev, size, size);

}



static void stm32_adfsdm_pcm_free(struct snd_pcm *pcm)

{

	struct snd_pcm_substream *substream;

	struct snd_soc_pcm_runtime *rtd;

	struct stm32_adfsdm_priv *priv;



	substream = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream;

	if (substream) {

		rtd = substream->private_data;

		priv = snd_soc_dai_get_drvdata(rtd->cpu_dai);



		snd_pcm_lib_preallocate_free_for_all(pcm);

	}

}



static struct snd_soc_platform_driver stm32_adfsdm_soc_platform = {

	.ops		= &stm32_adfsdm_pcm_ops,

	.pcm_new	= stm32_adfsdm_pcm_new,

	.pcm_free	= stm32_adfsdm_pcm_free,

};



static const struct of_device_id stm32_adfsdm_of_match[] = {

	{.compatible = "st,stm32h7-dfsdm-dai"},

	{}

};

MODULE_DEVICE_TABLE(of, stm32_adfsdm_of_match);



static int stm32_adfsdm_probe(struct platform_device *pdev)

{

	struct stm32_adfsdm_priv *priv;

	int ret;



	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);

	if (!priv)

		return -ENOMEM;



	priv->dev = &pdev->dev;

	priv->dai_drv = stm32_adfsdm_dai;



	dev_set_drvdata(&pdev->dev, priv);



	ret = devm_snd_soc_register_component(&pdev->dev,

					      &stm32_adfsdm_dai_component,

					      &priv->dai_drv, 1);

	if (ret < 0)

		return ret;



	/* Associate iio channel */

	priv->iio_ch  = devm_iio_channel_get_all(&pdev->dev);

	if (IS_ERR(priv->iio_ch))

		return PTR_ERR(priv->iio_ch);



	priv->iio_cb = iio_channel_get_all_cb(&pdev->dev, NULL, NULL);

	if (IS_ERR(priv->iio_cb))

		return PTR_ERR(priv->iio_ch);



	ret = devm_snd_soc_register_platform(&pdev->dev,

					     &stm32_adfsdm_soc_platform);

	if (ret < 0)

		dev_err(&pdev->dev, "%s: Failed to register PCM platform\n",

			__func__);



	return ret;

}



static struct platform_driver stm32_adfsdm_driver = {

	.driver = {

		   .name = STM32_ADFSDM_DRV_NAME,

		   .of_match_table = stm32_adfsdm_of_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");

MODULE_ALIAS("platform:" STM32_ADFSDM_DRV_NAME);