All of lore.kernel.org
 help / color / mirror / Atom feed
From: Arnaud Pouliquen <arnaud.pouliquen-qxv4g6HH51o@public.gmane.org>
To: Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>,
	Jonathan Cameron <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	Hartmut Knaack <knaack.h-Mmb7MZpHnFY@public.gmane.org>,
	Lars-Peter Clausen <lars-Qo5EllUWu/uELgA04lAiVw@public.gmane.org>,
	Peter Meerwald-Stadler
	<pmeerw-jW+XmwGofnusTnJN9+BGXg@public.gmane.org>,
	Jaroslav Kysela <perex-/Fr2/VpizcU@public.gmane.org>,
	Takashi Iwai <tiwai-IBi9RG/b67k@public.gmane.org>,
	Liam Girdwood <lgirdwood-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	alsa-devel-K7yf7f+aM1XWsZ/bQMPhNw@public.gmane.org,
	Maxime Coquelin
	<mcoquelin.stm32-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	Alexandre Torgue <alexandre.torgue-qxv4g6HH51o@public.gmane.org>,
	arnaud.pouliquen-qxv4g6HH51o@public.gmane.org
Subject: [PATCH v8 10/13] IIO: ADC: add stm32 DFSDM support for PDM microphone
Date: Mon, 11 Dec 2017 11:18:41 +0100	[thread overview]
Message-ID: <1512987524-2901-11-git-send-email-arnaud.pouliquen@st.com> (raw)
In-Reply-To: <1512987524-2901-1-git-send-email-arnaud.pouliquen-qxv4g6HH51o@public.gmane.org>

This code offers a way to handle PDM audio microphones in
ASOC framework. Audio driver should use consumer API.
A specific management is implemented for DMA, with a
callback, to allows to handle audio buffers efficiently.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen-qxv4g6HH51o@public.gmane.org>
---
 .../ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32      |  16 +
 drivers/iio/adc/stm32-dfsdm-adc.c                  | 508 ++++++++++++++++++++-
 include/linux/iio/adc/stm32-dfsdm-adc.h            |  18 +
 3 files changed, 534 insertions(+), 8 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32
 create mode 100644 include/linux/iio/adc/stm32-dfsdm-adc.h

diff --git a/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 b/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32
new file mode 100644
index 0000000..da98223
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32
@@ -0,0 +1,16 @@
+What:		/sys/bus/iio/devices/iio:deviceX/in_voltage_spi_clk_freq
+KernelVersion:	4.14
+Contact:	arnaud.pouliquen-qxv4g6HH51o@public.gmane.org
+Description:
+		For audio purpose only.
+		Used by audio driver to set/get the spi input frequency.
+		This is mandatory if DFSDM is slave on SPI bus, to
+		provide information on the SPI clock frequency during runtime
+		Notice that the SPI frequency should be a multiple of sample
+		frequency to ensure the precision.
+		if DFSDM input is SPI master
+			Reading  SPI clkout frequency,
+			error on writing
+		If DFSDM input is SPI Slave:
+			Reading returns value previously set.
+			Writing value before starting conversions.
\ No newline at end of file
diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
index 68b5920..2d6aed5 100644
--- a/drivers/iio/adc/stm32-dfsdm-adc.c
+++ b/drivers/iio/adc/stm32-dfsdm-adc.c
@@ -6,19 +6,25 @@
  * Author: Arnaud Pouliquen <arnaud.pouliquen-qxv4g6HH51o@public.gmane.org>.
  */
 
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
 #include <linux/interrupt.h>
 #include <linux/iio/buffer.h>
 #include <linux/iio/hw-consumer.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
 #include <linux/module.h>
-#include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
 
 #include "stm32-dfsdm.h"
 
+#define DFSDM_DMA_BUFFER_SIZE (4 * PAGE_SIZE)
+
 /* Conversion timeout */
 #define DFSDM_TIMEOUT_US 100000
 #define DFSDM_TIMEOUT (msecs_to_jiffies(DFSDM_TIMEOUT_US / 1000))
@@ -58,6 +64,18 @@ struct stm32_dfsdm_adc {
 	struct completion completion;
 	u32 *buffer;
 
+	/* Audio specific */
+	unsigned int spi_freq;  /* SPI bus clock frequency */
+	unsigned int sample_freq; /* Sample frequency after filter decimation */
+	int (*cb)(const void *data, size_t size, void *cb_priv);
+	void *cb_priv;
+
+	/* DMA */
+	u8 *rx_buf;
+	unsigned int bufi; /* Buffer current position */
+	unsigned int buf_sz; /* Buffer size */
+	struct dma_chan	*dma_chan;
+	dma_addr_t dma_buf;
 };
 
 struct stm32_dfsdm_str2field {
@@ -351,10 +369,63 @@ int stm32_dfsdm_channel_parse_of(struct stm32_dfsdm *dfsdm,
 	return 0;
 }
 
+static ssize_t dfsdm_adc_audio_get_spiclk(struct iio_dev *indio_dev,
+					  uintptr_t priv,
+					  const struct iio_chan_spec *chan,
+					  char *buf)
+{
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", adc->spi_freq);
+}
+
+static ssize_t dfsdm_adc_audio_set_spiclk(struct iio_dev *indio_dev,
+					  uintptr_t priv,
+					  const struct iio_chan_spec *chan,
+					  const char *buf, size_t len)
+{
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+	struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
+	struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[adc->ch_id];
+	unsigned int sample_freq = adc->sample_freq;
+	unsigned int spi_freq;
+	int ret;
+
+	dev_err(&indio_dev->dev, "enter %s\n", __func__);
+	/* If DFSDM is master on SPI, SPI freq can not be updated */
+	if (ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL)
+		return -EPERM;
+
+	ret = kstrtoint(buf, 0, &spi_freq);
+	if (ret)
+		return ret;
+
+	if (!spi_freq)
+		return -EINVAL;
+
+	if (sample_freq) {
+		if (spi_freq % sample_freq)
+			dev_warn(&indio_dev->dev,
+				 "Sampling rate not accurate (%d)\n",
+				 spi_freq / (spi_freq / sample_freq));
+
+		ret = stm32_dfsdm_set_osrs(fl, 0, (spi_freq / sample_freq));
+		if (ret < 0) {
+			dev_err(&indio_dev->dev,
+				"No filter parameters that match!\n");
+			return ret;
+		}
+	}
+	adc->spi_freq = spi_freq;
+
+	return len;
+}
+
 static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc, bool dma)
 {
 	struct regmap *regmap = adc->dfsdm->regmap;
 	int ret;
+	unsigned int dma_en = 0, cont_en = 0;
 
 	ret = stm32_dfsdm_start_channel(adc->dfsdm, adc->ch_id);
 	if (ret < 0)
@@ -365,6 +436,24 @@ static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc, bool dma)
 	if (ret < 0)
 		goto stop_channels;
 
+	if (dma) {
+		/* Enable DMA transfer*/
+		dma_en =  DFSDM_CR1_RDMAEN(1);
+		/* Enable conversion triggered by SPI clock*/
+		cont_en = DFSDM_CR1_RCONT(1);
+	}
+	/* Enable DMA transfer*/
+	ret = regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
+				 DFSDM_CR1_RDMAEN_MASK, dma_en);
+	if (ret < 0)
+		goto stop_channels;
+
+	/* Enable conversion triggered by SPI clock*/
+	ret = regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
+				 DFSDM_CR1_RCONT_MASK, cont_en);
+	if (ret < 0)
+		goto stop_channels;
+
 	ret = stm32_dfsdm_start_filter(adc->dfsdm, adc->fl_id);
 	if (ret < 0)
 		goto stop_channels;
@@ -398,6 +487,231 @@ static void stm32_dfsdm_stop_conv(struct stm32_dfsdm_adc *adc)
 	stm32_dfsdm_stop_channel(adc->dfsdm, adc->ch_id);
 }
 
+static int stm32_dfsdm_set_watermark(struct iio_dev *indio_dev,
+				     unsigned int val)
+{
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+	unsigned int watermark = DFSDM_DMA_BUFFER_SIZE / 2;
+
+	/*
+	 * DMA cyclic transfers are used, buffer is split into two periods.
+	 * There should be :
+	 * - always one buffer (period) DMA is working on
+	 * - one buffer (period) driver pushed to ASoC side.
+	 */
+	watermark = min(watermark, val * (unsigned int)(sizeof(u32)));
+	adc->buf_sz = watermark * 2;
+
+	return 0;
+}
+
+static unsigned int stm32_dfsdm_adc_dma_residue(struct stm32_dfsdm_adc *adc)
+{
+	struct dma_tx_state state;
+	enum dma_status status;
+
+	status = dmaengine_tx_status(adc->dma_chan,
+				     adc->dma_chan->cookie,
+				     &state);
+	if (status == DMA_IN_PROGRESS) {
+		/* Residue is size in bytes from end of buffer */
+		unsigned int i = adc->buf_sz - state.residue;
+		unsigned int size;
+
+		/* Return available bytes */
+		if (i >= adc->bufi)
+			size = i - adc->bufi;
+		else
+			size = adc->buf_sz + i - adc->bufi;
+
+		return size;
+	}
+
+	return 0;
+}
+
+static void stm32_dfsdm_audio_dma_buffer_done(void *data)
+{
+	struct iio_dev *indio_dev = data;
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+	int available = stm32_dfsdm_adc_dma_residue(adc);
+	size_t old_pos;
+
+	/*
+	 * FIXME: In Kernel interface does not support cyclic DMA buffer,and
+	 * offers only an interface to push data samples per samples.
+	 * For this reason IIO buffer interface is not used and interface is
+	 * bypassed using a private callback registered by ASoC.
+	 * This should be a temporary solution waiting a cyclic DMA engine
+	 * support in IIO.
+	 */
+
+	dev_dbg(&indio_dev->dev, "%s: pos = %d, available = %d\n", __func__,
+		adc->bufi, available);
+	old_pos = adc->bufi;
+
+	while (available >= indio_dev->scan_bytes) {
+		u32 *buffer = (u32 *)&adc->rx_buf[adc->bufi];
+
+		/* Mask 8 LSB that contains the channel ID */
+		*buffer = (*buffer & 0xFFFFFF00) << 8;
+		available -= indio_dev->scan_bytes;
+		adc->bufi += indio_dev->scan_bytes;
+		if (adc->bufi >= adc->buf_sz) {
+			if (adc->cb)
+				adc->cb(&adc->rx_buf[old_pos],
+					 adc->buf_sz - old_pos, adc->cb_priv);
+			adc->bufi = 0;
+			old_pos = 0;
+		}
+	}
+	if (adc->cb)
+		adc->cb(&adc->rx_buf[old_pos], adc->bufi - old_pos,
+			adc->cb_priv);
+}
+
+static int stm32_dfsdm_adc_dma_start(struct iio_dev *indio_dev)
+{
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+	struct dma_async_tx_descriptor *desc;
+	dma_cookie_t cookie;
+	int ret;
+
+	if (!adc->dma_chan)
+		return -EINVAL;
+
+	dev_dbg(&indio_dev->dev, "%s size=%d watermark=%d\n", __func__,
+		adc->buf_sz, adc->buf_sz / 2);
+
+	/* Prepare a DMA cyclic transaction */
+	desc = dmaengine_prep_dma_cyclic(adc->dma_chan,
+					 adc->dma_buf,
+					 adc->buf_sz, adc->buf_sz / 2,
+					 DMA_DEV_TO_MEM,
+					 DMA_PREP_INTERRUPT);
+	if (!desc)
+		return -EBUSY;
+
+	desc->callback = stm32_dfsdm_audio_dma_buffer_done;
+	desc->callback_param = indio_dev;
+
+	cookie = dmaengine_submit(desc);
+	ret = dma_submit_error(cookie);
+	if (ret) {
+		dmaengine_terminate_all(adc->dma_chan);
+		return ret;
+	}
+
+	/* Issue pending DMA requests */
+	dma_async_issue_pending(adc->dma_chan);
+
+	return 0;
+}
+
+static int stm32_dfsdm_postenable(struct iio_dev *indio_dev)
+{
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+	int ret;
+
+	/* Reset adc buffer index */
+	adc->bufi = 0;
+
+	ret = stm32_dfsdm_start_dfsdm(adc->dfsdm);
+	if (ret < 0)
+		return ret;
+
+	ret = stm32_dfsdm_start_conv(adc, true);
+	if (ret) {
+		dev_err(&indio_dev->dev, "Can't start conversion\n");
+		goto stop_dfsdm;
+	}
+
+	if (adc->dma_chan) {
+		ret = stm32_dfsdm_adc_dma_start(indio_dev);
+		if (ret) {
+			dev_err(&indio_dev->dev, "Can't start DMA\n");
+			goto err_stop_conv;
+		}
+	}
+
+	return 0;
+
+err_stop_conv:
+	stm32_dfsdm_stop_conv(adc);
+stop_dfsdm:
+	stm32_dfsdm_stop_dfsdm(adc->dfsdm);
+
+	return ret;
+}
+
+static int stm32_dfsdm_predisable(struct iio_dev *indio_dev)
+{
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+
+	if (adc->dma_chan)
+		dmaengine_terminate_all(adc->dma_chan);
+
+	stm32_dfsdm_stop_conv(adc);
+
+	stm32_dfsdm_stop_dfsdm(adc->dfsdm);
+
+	return 0;
+}
+
+static const struct iio_buffer_setup_ops stm32_dfsdm_buffer_setup_ops = {
+	.postenable = &stm32_dfsdm_postenable,
+	.predisable = &stm32_dfsdm_predisable,
+};
+
+/**
+ * stm32_dfsdm_get_buff_cb() - register a callback that will be called when
+ *                             DMA transfer period is achieved.
+ *
+ * @iio_dev: Handle to IIO device.
+ * @cb: Pointer to callback function:
+ *      - data: pointer to data buffer
+ *      - size: size in byte of the data buffer
+ *      - private: pointer to consumer private structure.
+ * @private: Pointer to consumer private structure.
+ */
+int stm32_dfsdm_get_buff_cb(struct iio_dev *iio_dev,
+			    int (*cb)(const void *data, size_t size,
+				      void *private),
+			    void *private)
+{
+	struct stm32_dfsdm_adc *adc;
+
+	if (!iio_dev)
+		return -EINVAL;
+	adc = iio_priv(iio_dev);
+
+	adc->cb = cb;
+	adc->cb_priv = private;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(stm32_dfsdm_get_buff_cb);
+
+/**
+ * stm32_dfsdm_release_buff_cb - unregister buffer callback
+ *
+ * @iio_dev: Handle to IIO device.
+ */
+int stm32_dfsdm_release_buff_cb(struct iio_dev *iio_dev)
+{
+	struct stm32_dfsdm_adc *adc;
+
+	if (!iio_dev)
+		return -EINVAL;
+	adc = iio_priv(iio_dev);
+
+	adc->cb = NULL;
+	adc->cb_priv = NULL;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(stm32_dfsdm_release_buff_cb);
+
 static int stm32_dfsdm_single_conv(struct iio_dev *indio_dev,
 				   const struct iio_chan_spec *chan, int *res)
 {
@@ -453,15 +767,41 @@ static int stm32_dfsdm_write_raw(struct iio_dev *indio_dev,
 {
 	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 	struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
+	struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[adc->ch_id];
+	unsigned int spi_freq = adc->spi_freq;
 	int ret = -EINVAL;
 
-	if (mask == IIO_CHAN_INFO_OVERSAMPLING_RATIO) {
+	switch (mask) {
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 		ret = stm32_dfsdm_set_osrs(fl, 0, val);
 		if (!ret)
 			adc->oversamp = val;
+
+		return ret;
+
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		if (!val)
+			return -EINVAL;
+		if (ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL)
+			spi_freq = adc->dfsdm->spi_master_freq;
+
+		if (spi_freq % val)
+			dev_warn(&indio_dev->dev,
+				 "Sampling rate not accurate (%d)\n",
+				 spi_freq / (spi_freq / val));
+
+		ret = stm32_dfsdm_set_osrs(fl, 0, (spi_freq / val));
+		if (ret < 0) {
+			dev_err(&indio_dev->dev,
+				"Not able to find parameter that match!\n");
+			return ret;
+		}
+		adc->sample_freq = val;
+
+		return 0;
 	}
 
-	return ret;
+	return -EINVAL;
 }
 
 static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev,
@@ -494,11 +834,22 @@ static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev,
 		*val = adc->oversamp;
 
 		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*val = adc->sample_freq;
+
+		return IIO_VAL_INT;
 	}
 
 	return -EINVAL;
 }
 
+static const struct iio_info stm32_dfsdm_info_audio = {
+	.hwfifo_set_watermark = stm32_dfsdm_set_watermark,
+	.read_raw = stm32_dfsdm_read_raw,
+	.write_raw = stm32_dfsdm_write_raw,
+};
+
 static const struct iio_info stm32_dfsdm_info_adc = {
 	.read_raw = stm32_dfsdm_read_raw,
 	.write_raw = stm32_dfsdm_write_raw,
@@ -531,6 +882,60 @@ static irqreturn_t stm32_dfsdm_irq(int irq, void *arg)
 	return IRQ_HANDLED;
 }
 
+/*
+ * Define external info for SPI Frequency and audio sampling rate that can be
+ * configured by ASoC driver through consumer.h API
+ */
+static const struct iio_chan_spec_ext_info dfsdm_adc_audio_ext_info[] = {
+	/* spi_clk_freq : clock freq on SPI/manchester bus used by channel */
+	{
+		.name = "spi_clk_freq",
+		.shared = IIO_SHARED_BY_TYPE,
+		.read = dfsdm_adc_audio_get_spiclk,
+		.write = dfsdm_adc_audio_set_spiclk,
+	},
+	{},
+};
+
+static int stm32_dfsdm_dma_request(struct iio_dev *indio_dev)
+{
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+	struct dma_slave_config config;
+	int ret;
+
+	adc->dma_chan = dma_request_slave_channel(&indio_dev->dev, "rx");
+	if (!adc->dma_chan)
+		return -EINVAL;
+
+	adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev,
+					 DFSDM_DMA_BUFFER_SIZE,
+					 &adc->dma_buf, GFP_KERNEL);
+	if (!adc->rx_buf) {
+		ret = -ENOMEM;
+		goto err_release;
+	}
+
+	/* Configure DMA channel to read data register */
+	memset(&config, 0, sizeof(config));
+	config.src_addr = (dma_addr_t)adc->dfsdm->phys_base;
+	config.src_addr += DFSDM_RDATAR(adc->fl_id);
+	config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+
+	ret = dmaengine_slave_config(adc->dma_chan, &config);
+	if (ret)
+		goto err_free;
+
+	return 0;
+
+err_free:
+	dma_free_coherent(adc->dma_chan->device->dev, DFSDM_DMA_BUFFER_SIZE,
+			  adc->rx_buf, adc->dma_buf);
+err_release:
+	dma_release_channel(adc->dma_chan);
+
+	return ret;
+}
+
 static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev,
 					 struct iio_chan_spec *ch)
 {
@@ -551,7 +956,12 @@ static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev,
 	ch->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
 	ch->info_mask_shared_by_all = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO);
 
-	ch->scan_type.sign = 'u';
+	if (adc->dev_data->type == DFSDM_AUDIO) {
+		ch->scan_type.sign = 's';
+		ch->ext_info = dfsdm_adc_audio_ext_info;
+	} else {
+		ch->scan_type.sign = 'u';
+	}
 	ch->scan_type.realbits = 24;
 	ch->scan_type.storagebits = 32;
 	adc->ch_id = ch->channel;
@@ -560,6 +970,64 @@ static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev,
 					  &adc->dfsdm->ch_list[ch->channel]);
 }
 
+static int stm32_dfsdm_audio_init(struct iio_dev *indio_dev)
+{
+	struct iio_chan_spec *ch;
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+	struct stm32_dfsdm_channel *d_ch;
+	int ret;
+
+	ret = stm32_dfsdm_dma_request(indio_dev);
+	if (ret) {
+		dev_err(&indio_dev->dev, "DMA request failed\n");
+		return ret;
+	}
+
+	indio_dev->modes |= INDIO_BUFFER_SOFTWARE;
+
+	ret = iio_triggered_buffer_setup(indio_dev,
+					 &iio_pollfunc_store_time,
+					 NULL,
+					 &stm32_dfsdm_buffer_setup_ops);
+	if (ret) {
+		dev_err(&indio_dev->dev, "Buffer setup failed\n");
+		goto err_dma_disable;
+	}
+
+	ch = devm_kzalloc(&indio_dev->dev, sizeof(*ch), GFP_KERNEL);
+	if (!ch)
+		return -ENOMEM;
+
+	ch->scan_index = 0;
+	ret = stm32_dfsdm_adc_chan_init_one(indio_dev, ch);
+	if (ret < 0) {
+		dev_err(&indio_dev->dev, "channels init failed\n");
+		goto err_buffer_cleanup;
+	}
+	ch->info_mask_separate = BIT(IIO_CHAN_INFO_SAMP_FREQ);
+
+	d_ch = &adc->dfsdm->ch_list[adc->ch_id];
+	if (d_ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL)
+		adc->spi_freq = adc->dfsdm->spi_master_freq;
+
+	indio_dev->num_channels = 1;
+	indio_dev->channels = ch;
+
+	return 0;
+
+err_buffer_cleanup:
+	iio_triggered_buffer_cleanup(indio_dev);
+
+err_dma_disable:
+	if (adc->dma_chan) {
+		dma_free_coherent(adc->dma_chan->device->dev,
+				  DFSDM_DMA_BUFFER_SIZE,
+				  adc->rx_buf, adc->dma_buf);
+		dma_release_channel(adc->dma_chan);
+	}
+	return ret;
+}
+
 static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev)
 {
 	struct iio_chan_spec *ch;
@@ -612,11 +1080,20 @@ static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_adc_data = {
 	.init = stm32_dfsdm_adc_init,
 };
 
+static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_audio_data = {
+	.type = DFSDM_AUDIO,
+	.init = stm32_dfsdm_audio_init,
+};
+
 static const struct of_device_id stm32_dfsdm_adc_match[] = {
 	{
 		.compatible = "st,stm32-dfsdm-adc",
 		.data = &stm32h7_dfsdm_adc_data,
 	},
+	{
+		.compatible = "st,stm32-dfsdm-dmic",
+		.data = &stm32h7_dfsdm_audio_data,
+	},
 	{}
 };
 
@@ -667,8 +1144,13 @@ static int stm32_dfsdm_adc_probe(struct platform_device *pdev)
 	name = devm_kzalloc(dev, sizeof("dfsdm-adc0"), GFP_KERNEL);
 	if (!name)
 		return -ENOMEM;
-	iio->info = &stm32_dfsdm_info_adc;
-	snprintf(name, sizeof("dfsdm-adc0"), "dfsdm-adc%d", adc->fl_id);
+	if (dev_data->type == DFSDM_AUDIO) {
+		iio->info = &stm32_dfsdm_info_audio;
+		snprintf(name, sizeof("dfsdm-pdm0"), "dfsdm-pdm%d", adc->fl_id);
+	} else {
+		iio->info = &stm32_dfsdm_info_adc;
+		snprintf(name, sizeof("dfsdm-adc0"), "dfsdm-adc%d", adc->fl_id);
+	}
 	iio->name = name;
 
 	/*
@@ -700,7 +1182,10 @@ static int stm32_dfsdm_adc_probe(struct platform_device *pdev)
 	if (ret < 0)
 		return ret;
 
-	return iio_device_register(iio);
+	iio_device_register(iio);
+	if (dev_data->type == DFSDM_AUDIO)
+		return devm_of_platform_populate(&pdev->dev);
+	return 0;
 }
 
 static int stm32_dfsdm_adc_remove(struct platform_device *pdev)
@@ -709,7 +1194,14 @@ static int stm32_dfsdm_adc_remove(struct platform_device *pdev)
 	struct iio_dev *indio_dev = iio_priv_to_dev(adc);
 
 	iio_device_unregister(indio_dev);
-
+	if (indio_dev->pollfunc)
+		iio_triggered_buffer_cleanup(indio_dev);
+	if (adc->dma_chan) {
+		dma_free_coherent(adc->dma_chan->device->dev,
+				  DFSDM_DMA_BUFFER_SIZE,
+				  adc->rx_buf, adc->dma_buf);
+		dma_release_channel(adc->dma_chan);
+	}
 	return 0;
 }
 
diff --git a/include/linux/iio/adc/stm32-dfsdm-adc.h b/include/linux/iio/adc/stm32-dfsdm-adc.h
new file mode 100644
index 0000000..e7dc7a5
--- /dev/null
+++ b/include/linux/iio/adc/stm32-dfsdm-adc.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * This file discribe the STM32 DFSDM IIO driver API for audio part
+ *
+ * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
+ * Author(s): Arnaud Pouliquen <arnaud.pouliquen-qxv4g6HH51o@public.gmane.org>.
+ */
+
+#ifndef STM32_DFSDM_ADC_H
+#define STM32_DFSDM_ADC_H
+
+int stm32_dfsdm_get_buff_cb(struct iio_dev *iio_dev,
+			    int (*cb)(const void *data, size_t size,
+				      void *private),
+			    void *private);
+int stm32_dfsdm_release_buff_cb(struct iio_dev *iio_dev);
+
+#endif
-- 
2.7.4

WARNING: multiple messages have this Message-ID (diff)
From: Arnaud Pouliquen <arnaud.pouliquen@st.com>
To: Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Jonathan Cameron <jic23@kernel.org>,
	Hartmut Knaack <knaack.h@gmx.de>,
	Lars-Peter Clausen <lars@metafoo.de>,
	Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
	Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>,
	Liam Girdwood <lgirdwood@gmail.com>,
	Mark Brown <broonie@kernel.org>
Cc: <devicetree@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-iio@vger.kernel.org>, <alsa-devel@alsa-project.org>,
	Maxime Coquelin <mcoquelin.stm32@gmail.com>,
	Alexandre Torgue <alexandre.torgue@st.com>,
	<arnaud.pouliquen@st.com>
Subject: [PATCH v8 10/13] IIO: ADC: add stm32 DFSDM support for PDM microphone
Date: Mon, 11 Dec 2017 11:18:41 +0100	[thread overview]
Message-ID: <1512987524-2901-11-git-send-email-arnaud.pouliquen@st.com> (raw)
In-Reply-To: <1512987524-2901-1-git-send-email-arnaud.pouliquen@st.com>

This code offers a way to handle PDM audio microphones in
ASOC framework. Audio driver should use consumer API.
A specific management is implemented for DMA, with a
callback, to allows to handle audio buffers efficiently.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
---
 .../ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32      |  16 +
 drivers/iio/adc/stm32-dfsdm-adc.c                  | 508 ++++++++++++++++++++-
 include/linux/iio/adc/stm32-dfsdm-adc.h            |  18 +
 3 files changed, 534 insertions(+), 8 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32
 create mode 100644 include/linux/iio/adc/stm32-dfsdm-adc.h

diff --git a/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 b/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32
new file mode 100644
index 0000000..da98223
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32
@@ -0,0 +1,16 @@
+What:		/sys/bus/iio/devices/iio:deviceX/in_voltage_spi_clk_freq
+KernelVersion:	4.14
+Contact:	arnaud.pouliquen@st.com
+Description:
+		For audio purpose only.
+		Used by audio driver to set/get the spi input frequency.
+		This is mandatory if DFSDM is slave on SPI bus, to
+		provide information on the SPI clock frequency during runtime
+		Notice that the SPI frequency should be a multiple of sample
+		frequency to ensure the precision.
+		if DFSDM input is SPI master
+			Reading  SPI clkout frequency,
+			error on writing
+		If DFSDM input is SPI Slave:
+			Reading returns value previously set.
+			Writing value before starting conversions.
\ No newline at end of file
diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
index 68b5920..2d6aed5 100644
--- a/drivers/iio/adc/stm32-dfsdm-adc.c
+++ b/drivers/iio/adc/stm32-dfsdm-adc.c
@@ -6,19 +6,25 @@
  * Author: Arnaud Pouliquen <arnaud.pouliquen@st.com>.
  */
 
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
 #include <linux/interrupt.h>
 #include <linux/iio/buffer.h>
 #include <linux/iio/hw-consumer.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
 #include <linux/module.h>
-#include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
 
 #include "stm32-dfsdm.h"
 
+#define DFSDM_DMA_BUFFER_SIZE (4 * PAGE_SIZE)
+
 /* Conversion timeout */
 #define DFSDM_TIMEOUT_US 100000
 #define DFSDM_TIMEOUT (msecs_to_jiffies(DFSDM_TIMEOUT_US / 1000))
@@ -58,6 +64,18 @@ struct stm32_dfsdm_adc {
 	struct completion completion;
 	u32 *buffer;
 
+	/* Audio specific */
+	unsigned int spi_freq;  /* SPI bus clock frequency */
+	unsigned int sample_freq; /* Sample frequency after filter decimation */
+	int (*cb)(const void *data, size_t size, void *cb_priv);
+	void *cb_priv;
+
+	/* DMA */
+	u8 *rx_buf;
+	unsigned int bufi; /* Buffer current position */
+	unsigned int buf_sz; /* Buffer size */
+	struct dma_chan	*dma_chan;
+	dma_addr_t dma_buf;
 };
 
 struct stm32_dfsdm_str2field {
@@ -351,10 +369,63 @@ int stm32_dfsdm_channel_parse_of(struct stm32_dfsdm *dfsdm,
 	return 0;
 }
 
+static ssize_t dfsdm_adc_audio_get_spiclk(struct iio_dev *indio_dev,
+					  uintptr_t priv,
+					  const struct iio_chan_spec *chan,
+					  char *buf)
+{
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", adc->spi_freq);
+}
+
+static ssize_t dfsdm_adc_audio_set_spiclk(struct iio_dev *indio_dev,
+					  uintptr_t priv,
+					  const struct iio_chan_spec *chan,
+					  const char *buf, size_t len)
+{
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+	struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
+	struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[adc->ch_id];
+	unsigned int sample_freq = adc->sample_freq;
+	unsigned int spi_freq;
+	int ret;
+
+	dev_err(&indio_dev->dev, "enter %s\n", __func__);
+	/* If DFSDM is master on SPI, SPI freq can not be updated */
+	if (ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL)
+		return -EPERM;
+
+	ret = kstrtoint(buf, 0, &spi_freq);
+	if (ret)
+		return ret;
+
+	if (!spi_freq)
+		return -EINVAL;
+
+	if (sample_freq) {
+		if (spi_freq % sample_freq)
+			dev_warn(&indio_dev->dev,
+				 "Sampling rate not accurate (%d)\n",
+				 spi_freq / (spi_freq / sample_freq));
+
+		ret = stm32_dfsdm_set_osrs(fl, 0, (spi_freq / sample_freq));
+		if (ret < 0) {
+			dev_err(&indio_dev->dev,
+				"No filter parameters that match!\n");
+			return ret;
+		}
+	}
+	adc->spi_freq = spi_freq;
+
+	return len;
+}
+
 static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc, bool dma)
 {
 	struct regmap *regmap = adc->dfsdm->regmap;
 	int ret;
+	unsigned int dma_en = 0, cont_en = 0;
 
 	ret = stm32_dfsdm_start_channel(adc->dfsdm, adc->ch_id);
 	if (ret < 0)
@@ -365,6 +436,24 @@ static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc, bool dma)
 	if (ret < 0)
 		goto stop_channels;
 
+	if (dma) {
+		/* Enable DMA transfer*/
+		dma_en =  DFSDM_CR1_RDMAEN(1);
+		/* Enable conversion triggered by SPI clock*/
+		cont_en = DFSDM_CR1_RCONT(1);
+	}
+	/* Enable DMA transfer*/
+	ret = regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
+				 DFSDM_CR1_RDMAEN_MASK, dma_en);
+	if (ret < 0)
+		goto stop_channels;
+
+	/* Enable conversion triggered by SPI clock*/
+	ret = regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
+				 DFSDM_CR1_RCONT_MASK, cont_en);
+	if (ret < 0)
+		goto stop_channels;
+
 	ret = stm32_dfsdm_start_filter(adc->dfsdm, adc->fl_id);
 	if (ret < 0)
 		goto stop_channels;
@@ -398,6 +487,231 @@ static void stm32_dfsdm_stop_conv(struct stm32_dfsdm_adc *adc)
 	stm32_dfsdm_stop_channel(adc->dfsdm, adc->ch_id);
 }
 
+static int stm32_dfsdm_set_watermark(struct iio_dev *indio_dev,
+				     unsigned int val)
+{
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+	unsigned int watermark = DFSDM_DMA_BUFFER_SIZE / 2;
+
+	/*
+	 * DMA cyclic transfers are used, buffer is split into two periods.
+	 * There should be :
+	 * - always one buffer (period) DMA is working on
+	 * - one buffer (period) driver pushed to ASoC side.
+	 */
+	watermark = min(watermark, val * (unsigned int)(sizeof(u32)));
+	adc->buf_sz = watermark * 2;
+
+	return 0;
+}
+
+static unsigned int stm32_dfsdm_adc_dma_residue(struct stm32_dfsdm_adc *adc)
+{
+	struct dma_tx_state state;
+	enum dma_status status;
+
+	status = dmaengine_tx_status(adc->dma_chan,
+				     adc->dma_chan->cookie,
+				     &state);
+	if (status == DMA_IN_PROGRESS) {
+		/* Residue is size in bytes from end of buffer */
+		unsigned int i = adc->buf_sz - state.residue;
+		unsigned int size;
+
+		/* Return available bytes */
+		if (i >= adc->bufi)
+			size = i - adc->bufi;
+		else
+			size = adc->buf_sz + i - adc->bufi;
+
+		return size;
+	}
+
+	return 0;
+}
+
+static void stm32_dfsdm_audio_dma_buffer_done(void *data)
+{
+	struct iio_dev *indio_dev = data;
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+	int available = stm32_dfsdm_adc_dma_residue(adc);
+	size_t old_pos;
+
+	/*
+	 * FIXME: In Kernel interface does not support cyclic DMA buffer,and
+	 * offers only an interface to push data samples per samples.
+	 * For this reason IIO buffer interface is not used and interface is
+	 * bypassed using a private callback registered by ASoC.
+	 * This should be a temporary solution waiting a cyclic DMA engine
+	 * support in IIO.
+	 */
+
+	dev_dbg(&indio_dev->dev, "%s: pos = %d, available = %d\n", __func__,
+		adc->bufi, available);
+	old_pos = adc->bufi;
+
+	while (available >= indio_dev->scan_bytes) {
+		u32 *buffer = (u32 *)&adc->rx_buf[adc->bufi];
+
+		/* Mask 8 LSB that contains the channel ID */
+		*buffer = (*buffer & 0xFFFFFF00) << 8;
+		available -= indio_dev->scan_bytes;
+		adc->bufi += indio_dev->scan_bytes;
+		if (adc->bufi >= adc->buf_sz) {
+			if (adc->cb)
+				adc->cb(&adc->rx_buf[old_pos],
+					 adc->buf_sz - old_pos, adc->cb_priv);
+			adc->bufi = 0;
+			old_pos = 0;
+		}
+	}
+	if (adc->cb)
+		adc->cb(&adc->rx_buf[old_pos], adc->bufi - old_pos,
+			adc->cb_priv);
+}
+
+static int stm32_dfsdm_adc_dma_start(struct iio_dev *indio_dev)
+{
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+	struct dma_async_tx_descriptor *desc;
+	dma_cookie_t cookie;
+	int ret;
+
+	if (!adc->dma_chan)
+		return -EINVAL;
+
+	dev_dbg(&indio_dev->dev, "%s size=%d watermark=%d\n", __func__,
+		adc->buf_sz, adc->buf_sz / 2);
+
+	/* Prepare a DMA cyclic transaction */
+	desc = dmaengine_prep_dma_cyclic(adc->dma_chan,
+					 adc->dma_buf,
+					 adc->buf_sz, adc->buf_sz / 2,
+					 DMA_DEV_TO_MEM,
+					 DMA_PREP_INTERRUPT);
+	if (!desc)
+		return -EBUSY;
+
+	desc->callback = stm32_dfsdm_audio_dma_buffer_done;
+	desc->callback_param = indio_dev;
+
+	cookie = dmaengine_submit(desc);
+	ret = dma_submit_error(cookie);
+	if (ret) {
+		dmaengine_terminate_all(adc->dma_chan);
+		return ret;
+	}
+
+	/* Issue pending DMA requests */
+	dma_async_issue_pending(adc->dma_chan);
+
+	return 0;
+}
+
+static int stm32_dfsdm_postenable(struct iio_dev *indio_dev)
+{
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+	int ret;
+
+	/* Reset adc buffer index */
+	adc->bufi = 0;
+
+	ret = stm32_dfsdm_start_dfsdm(adc->dfsdm);
+	if (ret < 0)
+		return ret;
+
+	ret = stm32_dfsdm_start_conv(adc, true);
+	if (ret) {
+		dev_err(&indio_dev->dev, "Can't start conversion\n");
+		goto stop_dfsdm;
+	}
+
+	if (adc->dma_chan) {
+		ret = stm32_dfsdm_adc_dma_start(indio_dev);
+		if (ret) {
+			dev_err(&indio_dev->dev, "Can't start DMA\n");
+			goto err_stop_conv;
+		}
+	}
+
+	return 0;
+
+err_stop_conv:
+	stm32_dfsdm_stop_conv(adc);
+stop_dfsdm:
+	stm32_dfsdm_stop_dfsdm(adc->dfsdm);
+
+	return ret;
+}
+
+static int stm32_dfsdm_predisable(struct iio_dev *indio_dev)
+{
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+
+	if (adc->dma_chan)
+		dmaengine_terminate_all(adc->dma_chan);
+
+	stm32_dfsdm_stop_conv(adc);
+
+	stm32_dfsdm_stop_dfsdm(adc->dfsdm);
+
+	return 0;
+}
+
+static const struct iio_buffer_setup_ops stm32_dfsdm_buffer_setup_ops = {
+	.postenable = &stm32_dfsdm_postenable,
+	.predisable = &stm32_dfsdm_predisable,
+};
+
+/**
+ * stm32_dfsdm_get_buff_cb() - register a callback that will be called when
+ *                             DMA transfer period is achieved.
+ *
+ * @iio_dev: Handle to IIO device.
+ * @cb: Pointer to callback function:
+ *      - data: pointer to data buffer
+ *      - size: size in byte of the data buffer
+ *      - private: pointer to consumer private structure.
+ * @private: Pointer to consumer private structure.
+ */
+int stm32_dfsdm_get_buff_cb(struct iio_dev *iio_dev,
+			    int (*cb)(const void *data, size_t size,
+				      void *private),
+			    void *private)
+{
+	struct stm32_dfsdm_adc *adc;
+
+	if (!iio_dev)
+		return -EINVAL;
+	adc = iio_priv(iio_dev);
+
+	adc->cb = cb;
+	adc->cb_priv = private;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(stm32_dfsdm_get_buff_cb);
+
+/**
+ * stm32_dfsdm_release_buff_cb - unregister buffer callback
+ *
+ * @iio_dev: Handle to IIO device.
+ */
+int stm32_dfsdm_release_buff_cb(struct iio_dev *iio_dev)
+{
+	struct stm32_dfsdm_adc *adc;
+
+	if (!iio_dev)
+		return -EINVAL;
+	adc = iio_priv(iio_dev);
+
+	adc->cb = NULL;
+	adc->cb_priv = NULL;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(stm32_dfsdm_release_buff_cb);
+
 static int stm32_dfsdm_single_conv(struct iio_dev *indio_dev,
 				   const struct iio_chan_spec *chan, int *res)
 {
@@ -453,15 +767,41 @@ static int stm32_dfsdm_write_raw(struct iio_dev *indio_dev,
 {
 	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 	struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
+	struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[adc->ch_id];
+	unsigned int spi_freq = adc->spi_freq;
 	int ret = -EINVAL;
 
-	if (mask == IIO_CHAN_INFO_OVERSAMPLING_RATIO) {
+	switch (mask) {
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 		ret = stm32_dfsdm_set_osrs(fl, 0, val);
 		if (!ret)
 			adc->oversamp = val;
+
+		return ret;
+
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		if (!val)
+			return -EINVAL;
+		if (ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL)
+			spi_freq = adc->dfsdm->spi_master_freq;
+
+		if (spi_freq % val)
+			dev_warn(&indio_dev->dev,
+				 "Sampling rate not accurate (%d)\n",
+				 spi_freq / (spi_freq / val));
+
+		ret = stm32_dfsdm_set_osrs(fl, 0, (spi_freq / val));
+		if (ret < 0) {
+			dev_err(&indio_dev->dev,
+				"Not able to find parameter that match!\n");
+			return ret;
+		}
+		adc->sample_freq = val;
+
+		return 0;
 	}
 
-	return ret;
+	return -EINVAL;
 }
 
 static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev,
@@ -494,11 +834,22 @@ static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev,
 		*val = adc->oversamp;
 
 		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*val = adc->sample_freq;
+
+		return IIO_VAL_INT;
 	}
 
 	return -EINVAL;
 }
 
+static const struct iio_info stm32_dfsdm_info_audio = {
+	.hwfifo_set_watermark = stm32_dfsdm_set_watermark,
+	.read_raw = stm32_dfsdm_read_raw,
+	.write_raw = stm32_dfsdm_write_raw,
+};
+
 static const struct iio_info stm32_dfsdm_info_adc = {
 	.read_raw = stm32_dfsdm_read_raw,
 	.write_raw = stm32_dfsdm_write_raw,
@@ -531,6 +882,60 @@ static irqreturn_t stm32_dfsdm_irq(int irq, void *arg)
 	return IRQ_HANDLED;
 }
 
+/*
+ * Define external info for SPI Frequency and audio sampling rate that can be
+ * configured by ASoC driver through consumer.h API
+ */
+static const struct iio_chan_spec_ext_info dfsdm_adc_audio_ext_info[] = {
+	/* spi_clk_freq : clock freq on SPI/manchester bus used by channel */
+	{
+		.name = "spi_clk_freq",
+		.shared = IIO_SHARED_BY_TYPE,
+		.read = dfsdm_adc_audio_get_spiclk,
+		.write = dfsdm_adc_audio_set_spiclk,
+	},
+	{},
+};
+
+static int stm32_dfsdm_dma_request(struct iio_dev *indio_dev)
+{
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+	struct dma_slave_config config;
+	int ret;
+
+	adc->dma_chan = dma_request_slave_channel(&indio_dev->dev, "rx");
+	if (!adc->dma_chan)
+		return -EINVAL;
+
+	adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev,
+					 DFSDM_DMA_BUFFER_SIZE,
+					 &adc->dma_buf, GFP_KERNEL);
+	if (!adc->rx_buf) {
+		ret = -ENOMEM;
+		goto err_release;
+	}
+
+	/* Configure DMA channel to read data register */
+	memset(&config, 0, sizeof(config));
+	config.src_addr = (dma_addr_t)adc->dfsdm->phys_base;
+	config.src_addr += DFSDM_RDATAR(adc->fl_id);
+	config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+
+	ret = dmaengine_slave_config(adc->dma_chan, &config);
+	if (ret)
+		goto err_free;
+
+	return 0;
+
+err_free:
+	dma_free_coherent(adc->dma_chan->device->dev, DFSDM_DMA_BUFFER_SIZE,
+			  adc->rx_buf, adc->dma_buf);
+err_release:
+	dma_release_channel(adc->dma_chan);
+
+	return ret;
+}
+
 static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev,
 					 struct iio_chan_spec *ch)
 {
@@ -551,7 +956,12 @@ static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev,
 	ch->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
 	ch->info_mask_shared_by_all = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO);
 
-	ch->scan_type.sign = 'u';
+	if (adc->dev_data->type == DFSDM_AUDIO) {
+		ch->scan_type.sign = 's';
+		ch->ext_info = dfsdm_adc_audio_ext_info;
+	} else {
+		ch->scan_type.sign = 'u';
+	}
 	ch->scan_type.realbits = 24;
 	ch->scan_type.storagebits = 32;
 	adc->ch_id = ch->channel;
@@ -560,6 +970,64 @@ static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev,
 					  &adc->dfsdm->ch_list[ch->channel]);
 }
 
+static int stm32_dfsdm_audio_init(struct iio_dev *indio_dev)
+{
+	struct iio_chan_spec *ch;
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+	struct stm32_dfsdm_channel *d_ch;
+	int ret;
+
+	ret = stm32_dfsdm_dma_request(indio_dev);
+	if (ret) {
+		dev_err(&indio_dev->dev, "DMA request failed\n");
+		return ret;
+	}
+
+	indio_dev->modes |= INDIO_BUFFER_SOFTWARE;
+
+	ret = iio_triggered_buffer_setup(indio_dev,
+					 &iio_pollfunc_store_time,
+					 NULL,
+					 &stm32_dfsdm_buffer_setup_ops);
+	if (ret) {
+		dev_err(&indio_dev->dev, "Buffer setup failed\n");
+		goto err_dma_disable;
+	}
+
+	ch = devm_kzalloc(&indio_dev->dev, sizeof(*ch), GFP_KERNEL);
+	if (!ch)
+		return -ENOMEM;
+
+	ch->scan_index = 0;
+	ret = stm32_dfsdm_adc_chan_init_one(indio_dev, ch);
+	if (ret < 0) {
+		dev_err(&indio_dev->dev, "channels init failed\n");
+		goto err_buffer_cleanup;
+	}
+	ch->info_mask_separate = BIT(IIO_CHAN_INFO_SAMP_FREQ);
+
+	d_ch = &adc->dfsdm->ch_list[adc->ch_id];
+	if (d_ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL)
+		adc->spi_freq = adc->dfsdm->spi_master_freq;
+
+	indio_dev->num_channels = 1;
+	indio_dev->channels = ch;
+
+	return 0;
+
+err_buffer_cleanup:
+	iio_triggered_buffer_cleanup(indio_dev);
+
+err_dma_disable:
+	if (adc->dma_chan) {
+		dma_free_coherent(adc->dma_chan->device->dev,
+				  DFSDM_DMA_BUFFER_SIZE,
+				  adc->rx_buf, adc->dma_buf);
+		dma_release_channel(adc->dma_chan);
+	}
+	return ret;
+}
+
 static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev)
 {
 	struct iio_chan_spec *ch;
@@ -612,11 +1080,20 @@ static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_adc_data = {
 	.init = stm32_dfsdm_adc_init,
 };
 
+static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_audio_data = {
+	.type = DFSDM_AUDIO,
+	.init = stm32_dfsdm_audio_init,
+};
+
 static const struct of_device_id stm32_dfsdm_adc_match[] = {
 	{
 		.compatible = "st,stm32-dfsdm-adc",
 		.data = &stm32h7_dfsdm_adc_data,
 	},
+	{
+		.compatible = "st,stm32-dfsdm-dmic",
+		.data = &stm32h7_dfsdm_audio_data,
+	},
 	{}
 };
 
@@ -667,8 +1144,13 @@ static int stm32_dfsdm_adc_probe(struct platform_device *pdev)
 	name = devm_kzalloc(dev, sizeof("dfsdm-adc0"), GFP_KERNEL);
 	if (!name)
 		return -ENOMEM;
-	iio->info = &stm32_dfsdm_info_adc;
-	snprintf(name, sizeof("dfsdm-adc0"), "dfsdm-adc%d", adc->fl_id);
+	if (dev_data->type == DFSDM_AUDIO) {
+		iio->info = &stm32_dfsdm_info_audio;
+		snprintf(name, sizeof("dfsdm-pdm0"), "dfsdm-pdm%d", adc->fl_id);
+	} else {
+		iio->info = &stm32_dfsdm_info_adc;
+		snprintf(name, sizeof("dfsdm-adc0"), "dfsdm-adc%d", adc->fl_id);
+	}
 	iio->name = name;
 
 	/*
@@ -700,7 +1182,10 @@ static int stm32_dfsdm_adc_probe(struct platform_device *pdev)
 	if (ret < 0)
 		return ret;
 
-	return iio_device_register(iio);
+	iio_device_register(iio);
+	if (dev_data->type == DFSDM_AUDIO)
+		return devm_of_platform_populate(&pdev->dev);
+	return 0;
 }
 
 static int stm32_dfsdm_adc_remove(struct platform_device *pdev)
@@ -709,7 +1194,14 @@ static int stm32_dfsdm_adc_remove(struct platform_device *pdev)
 	struct iio_dev *indio_dev = iio_priv_to_dev(adc);
 
 	iio_device_unregister(indio_dev);
-
+	if (indio_dev->pollfunc)
+		iio_triggered_buffer_cleanup(indio_dev);
+	if (adc->dma_chan) {
+		dma_free_coherent(adc->dma_chan->device->dev,
+				  DFSDM_DMA_BUFFER_SIZE,
+				  adc->rx_buf, adc->dma_buf);
+		dma_release_channel(adc->dma_chan);
+	}
 	return 0;
 }
 
diff --git a/include/linux/iio/adc/stm32-dfsdm-adc.h b/include/linux/iio/adc/stm32-dfsdm-adc.h
new file mode 100644
index 0000000..e7dc7a5
--- /dev/null
+++ b/include/linux/iio/adc/stm32-dfsdm-adc.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * This file discribe the STM32 DFSDM IIO driver API for audio part
+ *
+ * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
+ * Author(s): Arnaud Pouliquen <arnaud.pouliquen@st.com>.
+ */
+
+#ifndef STM32_DFSDM_ADC_H
+#define STM32_DFSDM_ADC_H
+
+int stm32_dfsdm_get_buff_cb(struct iio_dev *iio_dev,
+			    int (*cb)(const void *data, size_t size,
+				      void *private),
+			    void *private);
+int stm32_dfsdm_release_buff_cb(struct iio_dev *iio_dev);
+
+#endif
-- 
2.7.4


WARNING: multiple messages have this Message-ID (diff)
From: arnaud.pouliquen@st.com (Arnaud Pouliquen)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v8 10/13] IIO: ADC: add stm32 DFSDM support for PDM microphone
Date: Mon, 11 Dec 2017 11:18:41 +0100	[thread overview]
Message-ID: <1512987524-2901-11-git-send-email-arnaud.pouliquen@st.com> (raw)
In-Reply-To: <1512987524-2901-1-git-send-email-arnaud.pouliquen@st.com>

This code offers a way to handle PDM audio microphones in
ASOC framework. Audio driver should use consumer API.
A specific management is implemented for DMA, with a
callback, to allows to handle audio buffers efficiently.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
---
 .../ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32      |  16 +
 drivers/iio/adc/stm32-dfsdm-adc.c                  | 508 ++++++++++++++++++++-
 include/linux/iio/adc/stm32-dfsdm-adc.h            |  18 +
 3 files changed, 534 insertions(+), 8 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32
 create mode 100644 include/linux/iio/adc/stm32-dfsdm-adc.h

diff --git a/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 b/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32
new file mode 100644
index 0000000..da98223
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32
@@ -0,0 +1,16 @@
+What:		/sys/bus/iio/devices/iio:deviceX/in_voltage_spi_clk_freq
+KernelVersion:	4.14
+Contact:	arnaud.pouliquen at st.com
+Description:
+		For audio purpose only.
+		Used by audio driver to set/get the spi input frequency.
+		This is mandatory if DFSDM is slave on SPI bus, to
+		provide information on the SPI clock frequency during runtime
+		Notice that the SPI frequency should be a multiple of sample
+		frequency to ensure the precision.
+		if DFSDM input is SPI master
+			Reading  SPI clkout frequency,
+			error on writing
+		If DFSDM input is SPI Slave:
+			Reading returns value previously set.
+			Writing value before starting conversions.
\ No newline at end of file
diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
index 68b5920..2d6aed5 100644
--- a/drivers/iio/adc/stm32-dfsdm-adc.c
+++ b/drivers/iio/adc/stm32-dfsdm-adc.c
@@ -6,19 +6,25 @@
  * Author: Arnaud Pouliquen <arnaud.pouliquen@st.com>.
  */
 
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
 #include <linux/interrupt.h>
 #include <linux/iio/buffer.h>
 #include <linux/iio/hw-consumer.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
 #include <linux/module.h>
-#include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
 
 #include "stm32-dfsdm.h"
 
+#define DFSDM_DMA_BUFFER_SIZE (4 * PAGE_SIZE)
+
 /* Conversion timeout */
 #define DFSDM_TIMEOUT_US 100000
 #define DFSDM_TIMEOUT (msecs_to_jiffies(DFSDM_TIMEOUT_US / 1000))
@@ -58,6 +64,18 @@ struct stm32_dfsdm_adc {
 	struct completion completion;
 	u32 *buffer;
 
+	/* Audio specific */
+	unsigned int spi_freq;  /* SPI bus clock frequency */
+	unsigned int sample_freq; /* Sample frequency after filter decimation */
+	int (*cb)(const void *data, size_t size, void *cb_priv);
+	void *cb_priv;
+
+	/* DMA */
+	u8 *rx_buf;
+	unsigned int bufi; /* Buffer current position */
+	unsigned int buf_sz; /* Buffer size */
+	struct dma_chan	*dma_chan;
+	dma_addr_t dma_buf;
 };
 
 struct stm32_dfsdm_str2field {
@@ -351,10 +369,63 @@ int stm32_dfsdm_channel_parse_of(struct stm32_dfsdm *dfsdm,
 	return 0;
 }
 
+static ssize_t dfsdm_adc_audio_get_spiclk(struct iio_dev *indio_dev,
+					  uintptr_t priv,
+					  const struct iio_chan_spec *chan,
+					  char *buf)
+{
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", adc->spi_freq);
+}
+
+static ssize_t dfsdm_adc_audio_set_spiclk(struct iio_dev *indio_dev,
+					  uintptr_t priv,
+					  const struct iio_chan_spec *chan,
+					  const char *buf, size_t len)
+{
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+	struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
+	struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[adc->ch_id];
+	unsigned int sample_freq = adc->sample_freq;
+	unsigned int spi_freq;
+	int ret;
+
+	dev_err(&indio_dev->dev, "enter %s\n", __func__);
+	/* If DFSDM is master on SPI, SPI freq can not be updated */
+	if (ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL)
+		return -EPERM;
+
+	ret = kstrtoint(buf, 0, &spi_freq);
+	if (ret)
+		return ret;
+
+	if (!spi_freq)
+		return -EINVAL;
+
+	if (sample_freq) {
+		if (spi_freq % sample_freq)
+			dev_warn(&indio_dev->dev,
+				 "Sampling rate not accurate (%d)\n",
+				 spi_freq / (spi_freq / sample_freq));
+
+		ret = stm32_dfsdm_set_osrs(fl, 0, (spi_freq / sample_freq));
+		if (ret < 0) {
+			dev_err(&indio_dev->dev,
+				"No filter parameters that match!\n");
+			return ret;
+		}
+	}
+	adc->spi_freq = spi_freq;
+
+	return len;
+}
+
 static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc, bool dma)
 {
 	struct regmap *regmap = adc->dfsdm->regmap;
 	int ret;
+	unsigned int dma_en = 0, cont_en = 0;
 
 	ret = stm32_dfsdm_start_channel(adc->dfsdm, adc->ch_id);
 	if (ret < 0)
@@ -365,6 +436,24 @@ static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc, bool dma)
 	if (ret < 0)
 		goto stop_channels;
 
+	if (dma) {
+		/* Enable DMA transfer*/
+		dma_en =  DFSDM_CR1_RDMAEN(1);
+		/* Enable conversion triggered by SPI clock*/
+		cont_en = DFSDM_CR1_RCONT(1);
+	}
+	/* Enable DMA transfer*/
+	ret = regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
+				 DFSDM_CR1_RDMAEN_MASK, dma_en);
+	if (ret < 0)
+		goto stop_channels;
+
+	/* Enable conversion triggered by SPI clock*/
+	ret = regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
+				 DFSDM_CR1_RCONT_MASK, cont_en);
+	if (ret < 0)
+		goto stop_channels;
+
 	ret = stm32_dfsdm_start_filter(adc->dfsdm, adc->fl_id);
 	if (ret < 0)
 		goto stop_channels;
@@ -398,6 +487,231 @@ static void stm32_dfsdm_stop_conv(struct stm32_dfsdm_adc *adc)
 	stm32_dfsdm_stop_channel(adc->dfsdm, adc->ch_id);
 }
 
+static int stm32_dfsdm_set_watermark(struct iio_dev *indio_dev,
+				     unsigned int val)
+{
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+	unsigned int watermark = DFSDM_DMA_BUFFER_SIZE / 2;
+
+	/*
+	 * DMA cyclic transfers are used, buffer is split into two periods.
+	 * There should be :
+	 * - always one buffer (period) DMA is working on
+	 * - one buffer (period) driver pushed to ASoC side.
+	 */
+	watermark = min(watermark, val * (unsigned int)(sizeof(u32)));
+	adc->buf_sz = watermark * 2;
+
+	return 0;
+}
+
+static unsigned int stm32_dfsdm_adc_dma_residue(struct stm32_dfsdm_adc *adc)
+{
+	struct dma_tx_state state;
+	enum dma_status status;
+
+	status = dmaengine_tx_status(adc->dma_chan,
+				     adc->dma_chan->cookie,
+				     &state);
+	if (status == DMA_IN_PROGRESS) {
+		/* Residue is size in bytes from end of buffer */
+		unsigned int i = adc->buf_sz - state.residue;
+		unsigned int size;
+
+		/* Return available bytes */
+		if (i >= adc->bufi)
+			size = i - adc->bufi;
+		else
+			size = adc->buf_sz + i - adc->bufi;
+
+		return size;
+	}
+
+	return 0;
+}
+
+static void stm32_dfsdm_audio_dma_buffer_done(void *data)
+{
+	struct iio_dev *indio_dev = data;
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+	int available = stm32_dfsdm_adc_dma_residue(adc);
+	size_t old_pos;
+
+	/*
+	 * FIXME: In Kernel interface does not support cyclic DMA buffer,and
+	 * offers only an interface to push data samples per samples.
+	 * For this reason IIO buffer interface is not used and interface is
+	 * bypassed using a private callback registered by ASoC.
+	 * This should be a temporary solution waiting a cyclic DMA engine
+	 * support in IIO.
+	 */
+
+	dev_dbg(&indio_dev->dev, "%s: pos = %d, available = %d\n", __func__,
+		adc->bufi, available);
+	old_pos = adc->bufi;
+
+	while (available >= indio_dev->scan_bytes) {
+		u32 *buffer = (u32 *)&adc->rx_buf[adc->bufi];
+
+		/* Mask 8 LSB that contains the channel ID */
+		*buffer = (*buffer & 0xFFFFFF00) << 8;
+		available -= indio_dev->scan_bytes;
+		adc->bufi += indio_dev->scan_bytes;
+		if (adc->bufi >= adc->buf_sz) {
+			if (adc->cb)
+				adc->cb(&adc->rx_buf[old_pos],
+					 adc->buf_sz - old_pos, adc->cb_priv);
+			adc->bufi = 0;
+			old_pos = 0;
+		}
+	}
+	if (adc->cb)
+		adc->cb(&adc->rx_buf[old_pos], adc->bufi - old_pos,
+			adc->cb_priv);
+}
+
+static int stm32_dfsdm_adc_dma_start(struct iio_dev *indio_dev)
+{
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+	struct dma_async_tx_descriptor *desc;
+	dma_cookie_t cookie;
+	int ret;
+
+	if (!adc->dma_chan)
+		return -EINVAL;
+
+	dev_dbg(&indio_dev->dev, "%s size=%d watermark=%d\n", __func__,
+		adc->buf_sz, adc->buf_sz / 2);
+
+	/* Prepare a DMA cyclic transaction */
+	desc = dmaengine_prep_dma_cyclic(adc->dma_chan,
+					 adc->dma_buf,
+					 adc->buf_sz, adc->buf_sz / 2,
+					 DMA_DEV_TO_MEM,
+					 DMA_PREP_INTERRUPT);
+	if (!desc)
+		return -EBUSY;
+
+	desc->callback = stm32_dfsdm_audio_dma_buffer_done;
+	desc->callback_param = indio_dev;
+
+	cookie = dmaengine_submit(desc);
+	ret = dma_submit_error(cookie);
+	if (ret) {
+		dmaengine_terminate_all(adc->dma_chan);
+		return ret;
+	}
+
+	/* Issue pending DMA requests */
+	dma_async_issue_pending(adc->dma_chan);
+
+	return 0;
+}
+
+static int stm32_dfsdm_postenable(struct iio_dev *indio_dev)
+{
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+	int ret;
+
+	/* Reset adc buffer index */
+	adc->bufi = 0;
+
+	ret = stm32_dfsdm_start_dfsdm(adc->dfsdm);
+	if (ret < 0)
+		return ret;
+
+	ret = stm32_dfsdm_start_conv(adc, true);
+	if (ret) {
+		dev_err(&indio_dev->dev, "Can't start conversion\n");
+		goto stop_dfsdm;
+	}
+
+	if (adc->dma_chan) {
+		ret = stm32_dfsdm_adc_dma_start(indio_dev);
+		if (ret) {
+			dev_err(&indio_dev->dev, "Can't start DMA\n");
+			goto err_stop_conv;
+		}
+	}
+
+	return 0;
+
+err_stop_conv:
+	stm32_dfsdm_stop_conv(adc);
+stop_dfsdm:
+	stm32_dfsdm_stop_dfsdm(adc->dfsdm);
+
+	return ret;
+}
+
+static int stm32_dfsdm_predisable(struct iio_dev *indio_dev)
+{
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+
+	if (adc->dma_chan)
+		dmaengine_terminate_all(adc->dma_chan);
+
+	stm32_dfsdm_stop_conv(adc);
+
+	stm32_dfsdm_stop_dfsdm(adc->dfsdm);
+
+	return 0;
+}
+
+static const struct iio_buffer_setup_ops stm32_dfsdm_buffer_setup_ops = {
+	.postenable = &stm32_dfsdm_postenable,
+	.predisable = &stm32_dfsdm_predisable,
+};
+
+/**
+ * stm32_dfsdm_get_buff_cb() - register a callback that will be called when
+ *                             DMA transfer period is achieved.
+ *
+ * @iio_dev: Handle to IIO device.
+ * @cb: Pointer to callback function:
+ *      - data: pointer to data buffer
+ *      - size: size in byte of the data buffer
+ *      - private: pointer to consumer private structure.
+ * @private: Pointer to consumer private structure.
+ */
+int stm32_dfsdm_get_buff_cb(struct iio_dev *iio_dev,
+			    int (*cb)(const void *data, size_t size,
+				      void *private),
+			    void *private)
+{
+	struct stm32_dfsdm_adc *adc;
+
+	if (!iio_dev)
+		return -EINVAL;
+	adc = iio_priv(iio_dev);
+
+	adc->cb = cb;
+	adc->cb_priv = private;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(stm32_dfsdm_get_buff_cb);
+
+/**
+ * stm32_dfsdm_release_buff_cb - unregister buffer callback
+ *
+ * @iio_dev: Handle to IIO device.
+ */
+int stm32_dfsdm_release_buff_cb(struct iio_dev *iio_dev)
+{
+	struct stm32_dfsdm_adc *adc;
+
+	if (!iio_dev)
+		return -EINVAL;
+	adc = iio_priv(iio_dev);
+
+	adc->cb = NULL;
+	adc->cb_priv = NULL;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(stm32_dfsdm_release_buff_cb);
+
 static int stm32_dfsdm_single_conv(struct iio_dev *indio_dev,
 				   const struct iio_chan_spec *chan, int *res)
 {
@@ -453,15 +767,41 @@ static int stm32_dfsdm_write_raw(struct iio_dev *indio_dev,
 {
 	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 	struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
+	struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[adc->ch_id];
+	unsigned int spi_freq = adc->spi_freq;
 	int ret = -EINVAL;
 
-	if (mask == IIO_CHAN_INFO_OVERSAMPLING_RATIO) {
+	switch (mask) {
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 		ret = stm32_dfsdm_set_osrs(fl, 0, val);
 		if (!ret)
 			adc->oversamp = val;
+
+		return ret;
+
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		if (!val)
+			return -EINVAL;
+		if (ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL)
+			spi_freq = adc->dfsdm->spi_master_freq;
+
+		if (spi_freq % val)
+			dev_warn(&indio_dev->dev,
+				 "Sampling rate not accurate (%d)\n",
+				 spi_freq / (spi_freq / val));
+
+		ret = stm32_dfsdm_set_osrs(fl, 0, (spi_freq / val));
+		if (ret < 0) {
+			dev_err(&indio_dev->dev,
+				"Not able to find parameter that match!\n");
+			return ret;
+		}
+		adc->sample_freq = val;
+
+		return 0;
 	}
 
-	return ret;
+	return -EINVAL;
 }
 
 static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev,
@@ -494,11 +834,22 @@ static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev,
 		*val = adc->oversamp;
 
 		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*val = adc->sample_freq;
+
+		return IIO_VAL_INT;
 	}
 
 	return -EINVAL;
 }
 
+static const struct iio_info stm32_dfsdm_info_audio = {
+	.hwfifo_set_watermark = stm32_dfsdm_set_watermark,
+	.read_raw = stm32_dfsdm_read_raw,
+	.write_raw = stm32_dfsdm_write_raw,
+};
+
 static const struct iio_info stm32_dfsdm_info_adc = {
 	.read_raw = stm32_dfsdm_read_raw,
 	.write_raw = stm32_dfsdm_write_raw,
@@ -531,6 +882,60 @@ static irqreturn_t stm32_dfsdm_irq(int irq, void *arg)
 	return IRQ_HANDLED;
 }
 
+/*
+ * Define external info for SPI Frequency and audio sampling rate that can be
+ * configured by ASoC driver through consumer.h API
+ */
+static const struct iio_chan_spec_ext_info dfsdm_adc_audio_ext_info[] = {
+	/* spi_clk_freq : clock freq on SPI/manchester bus used by channel */
+	{
+		.name = "spi_clk_freq",
+		.shared = IIO_SHARED_BY_TYPE,
+		.read = dfsdm_adc_audio_get_spiclk,
+		.write = dfsdm_adc_audio_set_spiclk,
+	},
+	{},
+};
+
+static int stm32_dfsdm_dma_request(struct iio_dev *indio_dev)
+{
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+	struct dma_slave_config config;
+	int ret;
+
+	adc->dma_chan = dma_request_slave_channel(&indio_dev->dev, "rx");
+	if (!adc->dma_chan)
+		return -EINVAL;
+
+	adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev,
+					 DFSDM_DMA_BUFFER_SIZE,
+					 &adc->dma_buf, GFP_KERNEL);
+	if (!adc->rx_buf) {
+		ret = -ENOMEM;
+		goto err_release;
+	}
+
+	/* Configure DMA channel to read data register */
+	memset(&config, 0, sizeof(config));
+	config.src_addr = (dma_addr_t)adc->dfsdm->phys_base;
+	config.src_addr += DFSDM_RDATAR(adc->fl_id);
+	config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+
+	ret = dmaengine_slave_config(adc->dma_chan, &config);
+	if (ret)
+		goto err_free;
+
+	return 0;
+
+err_free:
+	dma_free_coherent(adc->dma_chan->device->dev, DFSDM_DMA_BUFFER_SIZE,
+			  adc->rx_buf, adc->dma_buf);
+err_release:
+	dma_release_channel(adc->dma_chan);
+
+	return ret;
+}
+
 static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev,
 					 struct iio_chan_spec *ch)
 {
@@ -551,7 +956,12 @@ static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev,
 	ch->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
 	ch->info_mask_shared_by_all = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO);
 
-	ch->scan_type.sign = 'u';
+	if (adc->dev_data->type == DFSDM_AUDIO) {
+		ch->scan_type.sign = 's';
+		ch->ext_info = dfsdm_adc_audio_ext_info;
+	} else {
+		ch->scan_type.sign = 'u';
+	}
 	ch->scan_type.realbits = 24;
 	ch->scan_type.storagebits = 32;
 	adc->ch_id = ch->channel;
@@ -560,6 +970,64 @@ static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev,
 					  &adc->dfsdm->ch_list[ch->channel]);
 }
 
+static int stm32_dfsdm_audio_init(struct iio_dev *indio_dev)
+{
+	struct iio_chan_spec *ch;
+	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+	struct stm32_dfsdm_channel *d_ch;
+	int ret;
+
+	ret = stm32_dfsdm_dma_request(indio_dev);
+	if (ret) {
+		dev_err(&indio_dev->dev, "DMA request failed\n");
+		return ret;
+	}
+
+	indio_dev->modes |= INDIO_BUFFER_SOFTWARE;
+
+	ret = iio_triggered_buffer_setup(indio_dev,
+					 &iio_pollfunc_store_time,
+					 NULL,
+					 &stm32_dfsdm_buffer_setup_ops);
+	if (ret) {
+		dev_err(&indio_dev->dev, "Buffer setup failed\n");
+		goto err_dma_disable;
+	}
+
+	ch = devm_kzalloc(&indio_dev->dev, sizeof(*ch), GFP_KERNEL);
+	if (!ch)
+		return -ENOMEM;
+
+	ch->scan_index = 0;
+	ret = stm32_dfsdm_adc_chan_init_one(indio_dev, ch);
+	if (ret < 0) {
+		dev_err(&indio_dev->dev, "channels init failed\n");
+		goto err_buffer_cleanup;
+	}
+	ch->info_mask_separate = BIT(IIO_CHAN_INFO_SAMP_FREQ);
+
+	d_ch = &adc->dfsdm->ch_list[adc->ch_id];
+	if (d_ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL)
+		adc->spi_freq = adc->dfsdm->spi_master_freq;
+
+	indio_dev->num_channels = 1;
+	indio_dev->channels = ch;
+
+	return 0;
+
+err_buffer_cleanup:
+	iio_triggered_buffer_cleanup(indio_dev);
+
+err_dma_disable:
+	if (adc->dma_chan) {
+		dma_free_coherent(adc->dma_chan->device->dev,
+				  DFSDM_DMA_BUFFER_SIZE,
+				  adc->rx_buf, adc->dma_buf);
+		dma_release_channel(adc->dma_chan);
+	}
+	return ret;
+}
+
 static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev)
 {
 	struct iio_chan_spec *ch;
@@ -612,11 +1080,20 @@ static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_adc_data = {
 	.init = stm32_dfsdm_adc_init,
 };
 
+static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_audio_data = {
+	.type = DFSDM_AUDIO,
+	.init = stm32_dfsdm_audio_init,
+};
+
 static const struct of_device_id stm32_dfsdm_adc_match[] = {
 	{
 		.compatible = "st,stm32-dfsdm-adc",
 		.data = &stm32h7_dfsdm_adc_data,
 	},
+	{
+		.compatible = "st,stm32-dfsdm-dmic",
+		.data = &stm32h7_dfsdm_audio_data,
+	},
 	{}
 };
 
@@ -667,8 +1144,13 @@ static int stm32_dfsdm_adc_probe(struct platform_device *pdev)
 	name = devm_kzalloc(dev, sizeof("dfsdm-adc0"), GFP_KERNEL);
 	if (!name)
 		return -ENOMEM;
-	iio->info = &stm32_dfsdm_info_adc;
-	snprintf(name, sizeof("dfsdm-adc0"), "dfsdm-adc%d", adc->fl_id);
+	if (dev_data->type == DFSDM_AUDIO) {
+		iio->info = &stm32_dfsdm_info_audio;
+		snprintf(name, sizeof("dfsdm-pdm0"), "dfsdm-pdm%d", adc->fl_id);
+	} else {
+		iio->info = &stm32_dfsdm_info_adc;
+		snprintf(name, sizeof("dfsdm-adc0"), "dfsdm-adc%d", adc->fl_id);
+	}
 	iio->name = name;
 
 	/*
@@ -700,7 +1182,10 @@ static int stm32_dfsdm_adc_probe(struct platform_device *pdev)
 	if (ret < 0)
 		return ret;
 
-	return iio_device_register(iio);
+	iio_device_register(iio);
+	if (dev_data->type == DFSDM_AUDIO)
+		return devm_of_platform_populate(&pdev->dev);
+	return 0;
 }
 
 static int stm32_dfsdm_adc_remove(struct platform_device *pdev)
@@ -709,7 +1194,14 @@ static int stm32_dfsdm_adc_remove(struct platform_device *pdev)
 	struct iio_dev *indio_dev = iio_priv_to_dev(adc);
 
 	iio_device_unregister(indio_dev);
-
+	if (indio_dev->pollfunc)
+		iio_triggered_buffer_cleanup(indio_dev);
+	if (adc->dma_chan) {
+		dma_free_coherent(adc->dma_chan->device->dev,
+				  DFSDM_DMA_BUFFER_SIZE,
+				  adc->rx_buf, adc->dma_buf);
+		dma_release_channel(adc->dma_chan);
+	}
 	return 0;
 }
 
diff --git a/include/linux/iio/adc/stm32-dfsdm-adc.h b/include/linux/iio/adc/stm32-dfsdm-adc.h
new file mode 100644
index 0000000..e7dc7a5
--- /dev/null
+++ b/include/linux/iio/adc/stm32-dfsdm-adc.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * This file discribe the STM32 DFSDM IIO driver API for audio part
+ *
+ * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
+ * Author(s): Arnaud Pouliquen <arnaud.pouliquen@st.com>.
+ */
+
+#ifndef STM32_DFSDM_ADC_H
+#define STM32_DFSDM_ADC_H
+
+int stm32_dfsdm_get_buff_cb(struct iio_dev *iio_dev,
+			    int (*cb)(const void *data, size_t size,
+				      void *private),
+			    void *private);
+int stm32_dfsdm_release_buff_cb(struct iio_dev *iio_dev);
+
+#endif
-- 
2.7.4

  parent reply	other threads:[~2017-12-11 10:18 UTC|newest]

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-12-11 10:18 [PATCH v8 00/13] Add STM32 DFSDM support Arnaud Pouliquen
2017-12-11 10:18 ` Arnaud Pouliquen
2017-12-11 10:18 ` Arnaud Pouliquen
2017-12-11 10:18 ` [PATCH v8 01/13] iio: Add hardware consumer buffer support Arnaud Pouliquen
2017-12-11 10:18   ` Arnaud Pouliquen
2017-12-11 10:18   ` Arnaud Pouliquen
2017-12-11 10:18 ` [PATCH v8 02/13] docs: driver-api: add iio hw consumer section Arnaud Pouliquen
2017-12-11 10:18   ` Arnaud Pouliquen
2017-12-11 10:18   ` Arnaud Pouliquen
2017-12-11 10:18 ` [PATCH v8 05/13] IIO: Add DT bindings for sigma delta adc modulator Arnaud Pouliquen
2017-12-11 10:18   ` Arnaud Pouliquen
2017-12-11 10:18   ` Arnaud Pouliquen
2017-12-11 10:18 ` [PATCH v8 06/13] IIO: ADC: add sigma delta modulator support Arnaud Pouliquen
2017-12-11 10:18   ` Arnaud Pouliquen
2017-12-11 10:18   ` Arnaud Pouliquen
     [not found] ` <1512987524-2901-1-git-send-email-arnaud.pouliquen-qxv4g6HH51o@public.gmane.org>
2017-12-11 10:18   ` [PATCH v8 03/13] IIO: hw_consumer: add devm_iio_hw_consumer_alloc Arnaud Pouliquen
2017-12-11 10:18     ` Arnaud Pouliquen
2017-12-11 10:18     ` Arnaud Pouliquen
2017-12-11 10:18   ` [PATCH v8 04/13] IIO: inkern: API for manipulating channel attributes Arnaud Pouliquen
2017-12-11 10:18     ` Arnaud Pouliquen
2017-12-11 10:18     ` Arnaud Pouliquen
2017-12-11 10:18   ` [PATCH v8 07/13] IIO: add DT bindings for stm32 DFSDM filter Arnaud Pouliquen
2017-12-11 10:18     ` Arnaud Pouliquen
2017-12-11 10:18     ` Arnaud Pouliquen
2017-12-11 10:18   ` [PATCH v8 08/13] IIO: ADC: add stm32 DFSDM core support Arnaud Pouliquen
2017-12-11 10:18     ` Arnaud Pouliquen
2017-12-11 10:18     ` Arnaud Pouliquen
2017-12-11 10:18   ` [PATCH v8 09/13] IIO: ADC: add STM32 DFSDM sigma delta ADC support Arnaud Pouliquen
2017-12-11 10:18     ` Arnaud Pouliquen
2017-12-11 10:18     ` Arnaud Pouliquen
2017-12-11 10:18   ` Arnaud Pouliquen [this message]
2017-12-11 10:18     ` [PATCH v8 10/13] IIO: ADC: add stm32 DFSDM support for PDM microphone Arnaud Pouliquen
2017-12-11 10:18     ` Arnaud Pouliquen
     [not found]     ` <1512987524-2901-11-git-send-email-arnaud.pouliquen-qxv4g6HH51o@public.gmane.org>
2017-12-12 20:27       ` Jonathan Cameron
2017-12-12 20:27         ` Jonathan Cameron
2017-12-12 20:27         ` Jonathan Cameron
2017-12-13  8:42         ` Arnaud Pouliquen
2017-12-13  8:42           ` Arnaud Pouliquen
2017-12-13  8:42           ` Arnaud Pouliquen
2017-12-13  9:18           ` Jonathan Cameron
2017-12-11 10:18   ` [PATCH v8 11/13] IIO: consumer: allow to set buffer sizes Arnaud Pouliquen
2017-12-11 10:18     ` Arnaud Pouliquen
2017-12-11 10:18     ` Arnaud Pouliquen
2017-12-11 10:18   ` [PATCH v8 12/13] ASoC: add bindings for stm32 DFSDM filter Arnaud Pouliquen
2017-12-11 10:18     ` Arnaud Pouliquen
2017-12-11 10:18     ` Arnaud Pouliquen
2017-12-11 10:18 ` [PATCH v8 13/13] ASoC: stm32: add DFSDM DAI support Arnaud Pouliquen
2017-12-11 10:18   ` Arnaud Pouliquen
2017-12-11 10:18   ` Arnaud Pouliquen
     [not found]   ` <1512987524-2901-14-git-send-email-arnaud.pouliquen-qxv4g6HH51o@public.gmane.org>
2018-01-10 11:12     ` Applied "ASoC: stm32: add DFSDM DAI support" to the asoc tree Mark Brown
2018-01-10 11:12       ` Mark Brown
2018-01-10 11:12       ` Mark Brown

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1512987524-2901-11-git-send-email-arnaud.pouliquen@st.com \
    --to=arnaud.pouliquen-qxv4g6hh51o@public.gmane.org \
    --cc=alexandre.torgue-qxv4g6HH51o@public.gmane.org \
    --cc=alsa-devel-K7yf7f+aM1XWsZ/bQMPhNw@public.gmane.org \
    --cc=broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org \
    --cc=devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org \
    --cc=knaack.h-Mmb7MZpHnFY@public.gmane.org \
    --cc=lars-Qo5EllUWu/uELgA04lAiVw@public.gmane.org \
    --cc=lgirdwood-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org \
    --cc=linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org \
    --cc=linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=mark.rutland-5wv7dgnIgG8@public.gmane.org \
    --cc=mcoquelin.stm32-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org \
    --cc=perex-/Fr2/VpizcU@public.gmane.org \
    --cc=pmeerw-jW+XmwGofnusTnJN9+BGXg@public.gmane.org \
    --cc=robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org \
    --cc=tiwai-IBi9RG/b67k@public.gmane.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.