Subject: [PATCH v9 13/13] ASoC: stm32: add DFSDM DAI support

From: [email-masked] (Jonathan Cameron)
Date: Sun, 17 Dec 2017 12:59:01 +0000

On Thu, 14 Dec 2017 09:58:05 +0100
Arnaud Pouliquen <[email-masked]> wrote:

> Add driver to handle DAI interface for PDM microphones connected
> to Digital Filter for Sigma Delta Modulators IP.
> 
> Signed-off-by: Arnaud Pouliquen <[email-masked]>

For the IIO parts (I'm not knowledgeable enough about the sound side to
offer a proper review!)
Reviewed-by: Jonathan Cameron <[email-masked]>

So Mark, over to you.  I'm happy if you want to do the immutable branch
once any issue you find are fixed, or I can do it.  I'm just looking
for acks or a pull request now.

Jonathan

> ---
>  sound/soc/stm/Kconfig        |  11 ++
>  sound/soc/stm/Makefile       |   3 +
>  sound/soc/stm/stm32_adfsdm.c | 347 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 361 insertions(+)
>  create mode 100644 sound/soc/stm/stm32_adfsdm.c
> 
> diff --git a/sound/soc/stm/Kconfig b/sound/soc/stm/Kconfig
> index 3398e6c..a78f770 100644
> --- a/sound/soc/stm/Kconfig
> +++ b/sound/soc/stm/Kconfig
> @@ -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
> diff --git a/sound/soc/stm/Makefile b/sound/soc/stm/Makefile
> index 4ed22e6..53e90e6 100644
> --- a/sound/soc/stm/Makefile
> +++ b/sound/soc/stm/Makefile
> @@ -12,3 +12,6 @@ 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
> diff --git a/sound/soc/stm/stm32_adfsdm.c b/sound/soc/stm/stm32_adfsdm.c
> new file mode 100644
> index 0000000..af50891
> --- /dev/null
> +++ b/sound/soc/stm/stm32_adfsdm.c
> @@ -0,0 +1,347 @@
> +// 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 <[email-masked]>
> + *          Olivier Moysan <[email-masked]>
> + */
> +
> +#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 <[email-masked]>");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:" STM32_ADFSDM_DRV_NAME);