Subject: [PATCH v6 13/13] ASoC: stm32: add DFSDM DAI support

From: [email-masked] (Jonathan Cameron)
Date: Sat, 2 Dec 2017 15:09:52 +0000

On Fri, 1 Dec 2017 18:40:20 +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]>

include tied up with the move of that enum in the earlier patch.
Other than that the IIO stuff looks fine to me.

Mark, given this set is moderately invasive on the IIO side and
should just drop in cleanly on the sound side of things, either
I could take it via IIO or one of us can do an immutable branch
and we take it through both trees.

Don't mind which but if I'm either taking the series or doing
an immutable branch I'll obviously be waiting on your review!

Also need time for Rob to check the updating bindings.

Anyhow, it's coming together reasonably nicely in the end.
Good work Arnaud!

Jonathan
> ---
> V5 to V6 update:
>  fix build warning
>  
>  sound/soc/stm/Kconfig        |  11 ++
>  sound/soc/stm/Makefile       |   3 +
>  sound/soc/stm/stm32_adfsdm.c | 386 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 400 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..890ec24
> --- /dev/null
> +++ b/sound/soc/stm/stm32_adfsdm.c
> @@ -0,0 +1,386 @@
> +/*
> + * 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]>
> + *
> + * License terms: GPL V2.0.
> + *
> + * 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 <linux/iio/iio.h>

I missed this before but a consumer should not need to include iio.h.
I would guess it was about that enum that I want you to move to types.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;
> +	bool allocated;
> +};
> +
> +struct stm32_adfsdm_data {
> +	unsigned int rate;	/* SNDRV_PCM_RATE value */
> +	unsigned int freq;	/* frequency in Hz */
> +};
> +
> +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;
> +
> +	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*/
> +	if (dir == SND_SOC_CLOCK_IN) {
> +		char str_freq[10];
> +
> +		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 = %lu\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);
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +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;
> +	int ret;
> +
> +	/*
> +	 * FIXME :
> +	 * A platform as been registered per DAI.
> +	 * In soc_new_pcm function, pcm_new callback is called for each
> +	 * component of the sound card. So if n dai links are created this
> +	 * function is called n times.
> +	 */
> +	if (priv->allocated)
> +		return 0;
> +
> +	ret = snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
> +						    priv->dev, size, size);
> +	if (!ret)
> +		priv->allocated = true;
> +
> +	return ret;
> +}
> +
> +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);
> +		priv->allocated = false;
> +	}
> +}
> +
> +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);