Re: [alsa-devel] [PATCH v7 13/13] ASoC: stm32: add DFSDM DAI support

On Fri, 8 Dec 2017 15:49:26 +0100 Arnaud Pouliquen arnaud.pouliquen@st.com wrote:

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

Signed-off-by: Arnaud Pouliquen arnaud.pouliquen@st.com

I don't know nearly enough about the sound side to comment on the details in here, but a few nitpicks inline I saw whilst glancing through it.

Thanks,

Jonathan

---

V6 to V7 updates:

• SPDX-Licensing.
• Supress workaround in stm32_adfsdm_pcm_new as issue fixed in generic code in recent kernel version.
• Fix kbuild report issue on a log parameter type.
• Suppress test in stm32_adfsdm_set_sysclk on clock direction.

sound/soc/stm/Kconfig | 11 ++ sound/soc/stm/Makefile | 3 + sound/soc/stm/stm32_adfsdm.c | 351 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 365 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..eef725e --- /dev/null +++ b/sound/soc/stm/stm32_adfsdm.c @@ -0,0 +1,351 @@ +// 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*/

Space before */

• 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);
  

• 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;
• ret = snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,

• 				    priv->dev, size, size);
  

• return ret;

nitpick. Nicer as return snd_pcm_lib_preallocate_pages_for_all(..

+}

+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);