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

Arnaud Pouliquen
2017-12-01T17:40:20Z

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-qxv4g6HH51o@public.gmane.org>
---
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 <arnaud.pouliquen-qxv4g6HH51o@public.gmane.org>
+ * Olivier Moysan <olivier.moysan-qxv4g6HH51o@public.gmane.org>
+ *
+ * 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>
+#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 <arnaud.pouliquen-qxv4g6HH51o@public.gmane.org>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" STM32_ADFSDM_DRV_NAME);
--
2.7.4