Add driver to handle DAI interface for PDM microphones connected
to Digital Filter for Sigma Delta mModulators IP.
Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxx>
---
include/sound/stm32-adfsdm.h | 80 ++++++++++
sound/soc/Kconfig | 1 +
sound/soc/Makefile | 1 +
sound/soc/stm/Kconfig | 10 ++
sound/soc/stm/Makefile | 2 +
sound/soc/stm/stm32_adfsdm.c | 365 +++++++++++++++++++++++++++++++++++++++++++
6 files changed, 459 insertions(+)
create mode 100644 include/sound/stm32-adfsdm.h
create mode 100644 sound/soc/stm/Kconfig
create mode 100644 sound/soc/stm/Makefile
create mode 100644 sound/soc/stm/stm32_adfsdm.c
diff --git a/include/sound/stm32-adfsdm.h b/include/sound/stm32-adfsdm.h
new file mode 100644
index 0000000..ff5899d
--- /dev/null
+++ b/include/sound/stm32-adfsdm.h
@@ -0,0 +1,80 @@
+/*
+ * This file is part of STM32 DFSDM mfd driver API
+ *
+ * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
+ * Author(s): Arnaud Pouliquen <arnaud.pouliquen@xxxxxx>.
+ *
+ * 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.
+ */
+#ifndef STM32_ADFSDM_H
+#define STM32_ADFSDM_H
+
+struct stm32_dfsdm_adc;
+
+/**
+ * struct stm32_dfsdm_hw_param - stm32 audio hardware params
+ * @rate: sampling rate
+ * @sample_bits: sample size in bits
+ * @max_scaling: effective scaling in bit computed by iio driver
+ */
+struct stm32_dfsdm_hw_param {
+ unsigned int rate;
+ unsigned int sample_bits;
+ unsigned int *max_scaling;
+};
+
+/*
+ * Potential improvement:
+ * Following structure and functions could be generic and declared in
+ * an asoc-iio.h
+ */
+struct stm32_adfsdm_codec_ops {
+ /*
+ * Set the SPI or manchester input Frequency
+ * Optional: not use if DFSDM is master on SPI
+ */
+ void (*set_sysclk)(struct stm32_dfsdm_adc *adc, unsigned int freq);
+
+ /*
+ * Set expected audio sampling rate and format.
+ * Precision is returned to allow to rescale samples
+ */
+ int (*set_hwparam)(struct stm32_dfsdm_adc *adc,
+ struct stm32_dfsdm_hw_param *params);
+
+ /* Called when ASoC starts an audio stream setup. */
+ int (*audio_startup)(struct stm32_dfsdm_adc *adc);
+
+ /* Shuts down the audio stream. */
+ void (*audio_shutdown)(struct stm32_dfsdm_adc *adc);
+
+ /*
+ * Provides DMA source physicla addr to allow ALsa to handle DMA
+ * transfers.
+ */
+ dma_addr_t (*get_dma_source)(struct stm32_dfsdm_adc *adc);
+
+ /* Register callback to treat overrun issues */
+ void (*register_xrun_cb)(struct stm32_dfsdm_adc *adc,
+ void (*overrun_cb)(void *context),
+ void *context);
+
+};
+
+/* stm32 dfsdm initalization data */
+struct stm32_adfsdm_pdata {
+ const struct stm32_adfsdm_codec_ops *ops;
+ struct stm32_dfsdm_adc *adc;
+};
+
+#define STM32_ADFSDM_DRV_NAME "stm32-dfsdm-audio"
+#endif
diff --git a/sound/soc/Kconfig b/sound/soc/Kconfig
index 182d92e..3836ebe 100644
--- a/sound/soc/Kconfig
+++ b/sound/soc/Kconfig
@@ -63,6 +63,7 @@ source "sound/soc/sh/Kconfig"
source "sound/soc/sirf/Kconfig"
source "sound/soc/spear/Kconfig"
source "sound/soc/sti/Kconfig"
+source "sound/soc/stm/Kconfig"
source "sound/soc/sunxi/Kconfig"
source "sound/soc/tegra/Kconfig"
source "sound/soc/txx9/Kconfig"
diff --git a/sound/soc/Makefile b/sound/soc/Makefile
index 9a30f21..5440cf7 100644
--- a/sound/soc/Makefile
+++ b/sound/soc/Makefile
@@ -43,6 +43,7 @@ obj-$(CONFIG_SND_SOC) += sh/
obj-$(CONFIG_SND_SOC) += sirf/
obj-$(CONFIG_SND_SOC) += spear/
obj-$(CONFIG_SND_SOC) += sti/
+obj-$(CONFIG_SND_SOC) += stm/
obj-$(CONFIG_SND_SOC) += sunxi/
obj-$(CONFIG_SND_SOC) += tegra/
obj-$(CONFIG_SND_SOC) += txx9/
diff --git a/sound/soc/stm/Kconfig b/sound/soc/stm/Kconfig
new file mode 100644
index 0000000..041ddb9
--- /dev/null
+++ b/sound/soc/stm/Kconfig
@@ -0,0 +1,10 @@
+menuconfig 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
+ 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.
\ No newline at end of file
diff --git a/sound/soc/stm/Makefile b/sound/soc/stm/Makefile
new file mode 100644
index 0000000..ea90240
--- /dev/null
+++ b/sound/soc/stm/Makefile
@@ -0,0 +1,2 @@
+#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..4488461
--- /dev/null
+++ b/sound/soc/stm/stm32_adfsdm.c
@@ -0,0 +1,365 @@
+/*
+ * This file is part of STM32 DFSDM ASoC DAI driver
+ *
+ * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
+ * Authors: Arnaud Pouliquen <arnaud.pouliquen@xxxxxx>
+ * Olivier Moysan <olivier.moysan@xxxxxx>
+ *
+ * License type: GPLv2
+ *
+ * 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 <sound/dmaengine_pcm.h>
+#include <sound/stm32-adfsdm.h>
+
+#define STM32_ADFSDM_DATA_MASK GENMASK(31, 8)
+
+struct stm32_adfsdm_priv {
+ struct snd_soc_dai_driver dai_drv;
+ struct stm32_adfsdm_pdata *pdata; /* platform data set by IIO driver */
+ struct snd_dmaengine_dai_dma_data dma_data; /* dma config */
+ struct snd_pcm_substream *substream;
+ struct snd_pcm_hw_constraint_list rates_const;
+ unsigned long dmic_clk; /* SPI or manchester input clock frequency */
+ unsigned int fl_id; /* filter instance ID */
+ unsigned int order; /* filter order */
+ unsigned int max_scaling; /* max scaling for audio samples */
+};
+
+struct stm32_adfsdm_data {
+ unsigned int rate; /* SNDRV_PCM_RATE value */
+ unsigned int freq; /* frequency in Hz */
+};
+
+static const struct stm32_adfsdm_data stm32_dfsdm_filter[] = {
+ { .rate = SNDRV_PCM_RATE_8000, .freq = 8000 },
+ { .rate = SNDRV_PCM_RATE_16000, .freq = 16000 },
+ { .rate = SNDRV_PCM_RATE_32000, .freq = 32000 },
+};
+
+static const struct snd_pcm_hardware stm32_adfsdm_pcm_hw = {
+ .info = SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
+ SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_MMAP |
+ SNDRV_PCM_INFO_MMAP_VALID,
+ .formats = SNDRV_PCM_FMTBIT_S24_LE,
+
+ .rate_min = 8000,
+ .rate_max = 32000,
+
+ .channels_min = 1,
+ .channels_max = 1,
+
+ .periods_min = 2,
+ .periods_max = 48,
+
+ .period_bytes_min = 40, /* 8 khz 5 ms */
+ .period_bytes_max = 4 * PAGE_SIZE,
+ .buffer_bytes_max = 16 * PAGE_SIZE
+};
+
+static int stm32_adfsdm_get_supported_rates(struct snd_soc_dai *dai,
+ unsigned int *rates)
+{
+ struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
+ struct stm32_adfsdm_pdata *pdata = priv->pdata;
+ struct stm32_dfsdm_hw_param params;
+ unsigned int max_scaling, i;
+ int ret;
+
+ *rates = 0;
+
+ for (i = 0; i < ARRAY_SIZE(stm32_dfsdm_filter); i++) {
+ /*
+ * Check that clkout_freq is compatible
+ * Try to find one solution for filter and integrator
+ * oversampling ratio.
+ */
+
+ params.rate = stm32_dfsdm_filter[i].freq;
+ params.sample_bits = 24;
+ params.max_scaling = &max_scaling;
+
+ ret = pdata->ops->set_hwparam(pdata->adc, ¶ms);
+ if (!ret) {
+ *rates |= 1 << i;
+ dev_err(dai->dev, "%s: %d rate supported\n", __func__,
+ stm32_dfsdm_filter[i].freq);
+ }
+ }
+
+ if (!*rates) {
+ dev_err(dai->dev, "%s: no matched rate found\n", __func__);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int stm32_adfsdm_copy(struct snd_pcm_substream *substream, int channel,
+ snd_pcm_uframes_t pos,
+ void __user *buf, snd_pcm_uframes_t count)
+{
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct snd_soc_pcm_runtime *rtd = substream->private_data;
+ struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(rtd->cpu_dai);
+ int *ptr = (int *)(runtime->dma_area + frames_to_bytes(runtime, pos));
+ char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, pos);
+ ssize_t bytes = frames_to_bytes(runtime, count);
+ ssize_t sample_cnt = bytes_to_samples(runtime, bytes);
+ unsigned int shift = 24 -priv->max_scaling;
+
+ /*
+ * Audio samples are available on 24 MSBs of the DFSDM DATAR register.
+ * We need to mask 8 LSB control bits...
+ * Additionnaly sample scaling depends on decimation and can need shift
+ * to be aligned on 32-bit word MSB.
+ */
+ if (shift > 0) {
+ do {
+ *ptr <<= shift & STM32_ADFSDM_DATA_MASK;
+ ptr++;
+ } while (--sample_cnt);
+ } else {
+ do {
+ *ptr &= STM32_ADFSDM_DATA_MASK;
+ ptr++;
+ } while (--sample_cnt);
+ }
+
+ return copy_to_user(buf, hwbuf, bytes);
+}
+
+static void stm32_dfsdm_xrun(void *context)
+{
+ struct snd_soc_dai *dai = context;
+ struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
+
+ snd_pcm_stream_lock(priv->substream);
+ dev_dbg(dai->dev, "%s:unexpected overrun\n", __func__);
+ /* Stop the player */
+ snd_pcm_stop(priv->substream, SNDRV_PCM_STATE_XRUN);
+ snd_pcm_stream_unlock(priv->substream);
+}
+
+static int stm32_adfsdm_startup(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
+
+ priv->substream = substream;
+
+ dev_dbg(dai->dev, "%s: enter\n", __func__);
+ return 0;
+ return snd_pcm_hw_constraint_list(substream->runtime, 0,
+ SNDRV_PCM_HW_PARAM_RATE,
+ &priv->rates_const);
+}
+
+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);
+
+ dev_dbg(dai->dev, "%s: enter\n", __func__);
+ priv->substream = NULL;
+}
+
+static int stm32_adfsdm_dai_hw_params(struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params,
+ struct snd_soc_dai *dai)
+{
+ struct snd_dmaengine_dai_dma_data *dma_data;
+ struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
+ struct stm32_adfsdm_pdata *pdata = priv->pdata;
+ struct stm32_dfsdm_hw_param df_params;
+
+ dev_dbg(dai->dev, "%s: enter\n", __func__);
+ dma_data = snd_soc_dai_get_dma_data(dai, substream);
+ dma_data->maxburst = 1;
+
+ df_params.rate = substream->runtime->rate;
+ df_params.sample_bits = substream->runtime->sample_bits;
+ df_params.max_scaling = &priv->max_scaling;
+
+ return pdata->ops->set_hwparam(pdata->adc, &df_params);
+}
+
+static int stm32_adfsdm_trigger(struct snd_pcm_substream *substream, int cmd,
+ struct snd_soc_dai *dai)
+{
+ struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
+ struct stm32_adfsdm_pdata *pdata = priv->pdata;
+
+ dev_dbg(dai->dev, "%s: enter\n", __func__);
+
+ switch (cmd) {
+ case SNDRV_PCM_TRIGGER_START:
+ case SNDRV_PCM_TRIGGER_RESUME:
+ return pdata->ops->audio_startup(pdata->adc);
+ case SNDRV_PCM_TRIGGER_SUSPEND:
+ case SNDRV_PCM_TRIGGER_STOP:
+ pdata->ops->audio_shutdown(pdata->adc);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int stm32_adfsdm_set_dai_fmt(struct snd_soc_dai *dai, unsigned int fmt)
+{
+ struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
+ unsigned int cb = fmt & SND_SOC_DAIFMT_MASTER_MASK;
+
+ dev_dbg(dai->dev, "%s: enter\n", __func__);
+
+ if ((cb == SND_SOC_DAIFMT_CBM_CFM) || (cb == SND_SOC_DAIFMT_CBM_CFS)) {
+ /* Digital microphone is clocked by external clock */
+ if (!priv->dmic_clk) {
+ dev_err(dai->dev,
+ "system-clock-frequency not defined\n");
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+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);
+ struct stm32_adfsdm_pdata *pdata = priv->pdata;
+
+ dev_dbg(dai->dev, "%s: enter for dai %d\n", __func__, dai->id);
+ if (dir == SND_SOC_CLOCK_IN) {
+ pdata->ops->set_sysclk(pdata->adc, freq);
+ priv->dmic_clk = freq;
+ }
+
+ /* Determine supported rate which depends on SPI/manchester clock */
+ return stm32_adfsdm_get_supported_rates(dai, &priv->rates_const.mask);
+}
+
+static const struct snd_soc_dai_ops stm32_adfsdm_dai_ops = {
+ .startup = stm32_adfsdm_startup,
+ .shutdown = stm32_adfsdm_shutdown,
+ .hw_params = stm32_adfsdm_dai_hw_params,
+ .set_fmt = stm32_adfsdm_set_dai_fmt,
+ .set_sysclk = stm32_adfsdm_set_sysclk,
+ .trigger = stm32_adfsdm_trigger,
+};
+
+static int stm32_adfsdm_dai_probe(struct snd_soc_dai *dai)
+{
+ struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
+ struct snd_dmaengine_dai_dma_data *dma = &priv->dma_data;
+ struct stm32_adfsdm_pdata *pdata = priv->pdata;
+
+ dev_dbg(dai->dev, "%s: enter for dai %d\n", __func__, dai->id);
+
+ /* DMA settings */
+ snd_soc_dai_init_dma_data(dai, NULL, dma);
+ dma->addr = pdata->ops->get_dma_source(pdata->adc);
+ dma->addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+
+ pdata->ops->register_xrun_cb(priv->pdata->adc, stm32_dfsdm_xrun, dai);
+
+ return 0;
+}
+
+static int stm32_adfsdm_dai_remove(struct snd_soc_dai *dai)
+{
+ dev_dbg(dai->dev, "%s: enter for dai %d\n", __func__, dai->id);
+
+ return 0;
+}
+
+static const struct snd_soc_dai_driver stm32_adfsdm_dai = {
+ .capture = {
+ .channels_min = 1,
+ .channels_max = 1,
+ .formats = SNDRV_PCM_FMTBIT_S24_LE,
+ .rates = (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_16000 |
+ SNDRV_PCM_RATE_32000),
+ },
+ .probe = stm32_adfsdm_dai_probe,
+ .remove = stm32_adfsdm_dai_remove,
+ .ops = &stm32_adfsdm_dai_ops,
+};
+
+static const struct snd_soc_component_driver stm32_adfsdm_dai_component = {
+ .name = "sti_cpu_dai",
+};
+
+static const struct snd_dmaengine_pcm_config dmaengine_pcm_config = {
+ .pcm_hardware = &stm32_adfsdm_pcm_hw,
+ .prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
+ .copy = stm32_adfsdm_copy,
+};
+
+static int stm32_adfsdm_probe(struct platform_device *pdev)
+{
+ struct stm32_adfsdm_priv *priv;
+ struct stm32_adfsdm_pdata *pdata = pdev->dev.platform_data;
+ int ret;
+
+ dev_dbg(&pdev->dev, "%s: enter for node %p\n", __func__,
+ pdev->dev.parent->of_node->name);
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->pdata = pdata;
+
+ priv->dai_drv = stm32_adfsdm_dai;
+ priv->dai_drv.name = pdev->dev.parent->of_node->name;
+ priv->dai_drv.capture.stream_name = pdev->dev.parent->of_node->name;
+
+ 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;
+
+ ret = devm_snd_dmaengine_pcm_register(pdev->dev.parent,
+ &dmaengine_pcm_config, 0);
+ if (ret < 0)
+ dev_err(&pdev->dev, "failed to register dma pcm config\n");
+
+ return ret;
+}
+
+static struct platform_driver stm32_adfsdm_driver = {
+ .driver = {
+ .name = STM32_ADFSDM_DRV_NAME,
+ },
+ .probe = stm32_adfsdm_probe,
+};
+
+module_platform_driver(stm32_adfsdm_driver);
+
+MODULE_DESCRIPTION("stm32 DFSDM DAI driver");
+MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@xxxxxx>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" STM32_ADFSDM_DRV_NAME);
--
1.9.1
--
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