mirror of
				https://github.com/torvalds/linux.git
				synced 2025-11-04 10:40:15 +02:00 
			
		
		
		
	IIO: ADC: add stm32 DFSDM support for PDM microphone
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> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
		
							parent
							
								
									e2e6771c64
								
							
						
					
					
						commit
						eca949800d
					
				
					 3 changed files with 529 additions and 7 deletions
				
			
		
							
								
								
									
										16
									
								
								Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32
									
									
									
									
									
										Normal file
									
								
							
							
						
						
									
										16
									
								
								Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32
									
									
									
									
									
										Normal file
									
								
							| 
						 | 
				
			
			@ -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.
 | 
			
		||||
| 
						 | 
				
			
			@ -6,19 +6,23 @@
 | 
			
		|||
 * 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/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 +62,18 @@ 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 +367,63 @@ 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 +434,24 @@ 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 +485,231 @@ 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 +765,41 @@ 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,
 | 
			
		||||
| 
						 | 
				
			
			@ -493,12 +831,23 @@ static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev,
 | 
			
		|||
	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 | 
			
		||||
		*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 +880,70 @@ 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 void stm32_dfsdm_dma_release(struct iio_dev *indio_dev)
 | 
			
		||||
{
 | 
			
		||||
	struct stm32_dfsdm_adc *adc = iio_priv(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);
 | 
			
		||||
	}
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
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 = {
 | 
			
		||||
		.src_addr = (dma_addr_t)adc->dfsdm->phys_base +
 | 
			
		||||
			DFSDM_RDATAR(adc->fl_id),
 | 
			
		||||
		.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
 | 
			
		||||
	};
 | 
			
		||||
	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;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	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 +964,12 @@ 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 +978,39 @@ 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;
 | 
			
		||||
 | 
			
		||||
	indio_dev->modes |= INDIO_BUFFER_SOFTWARE;
 | 
			
		||||
	indio_dev->setup_ops = &stm32_dfsdm_buffer_setup_ops;
 | 
			
		||||
 | 
			
		||||
	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");
 | 
			
		||||
		return ret;
 | 
			
		||||
	}
 | 
			
		||||
	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 stm32_dfsdm_dma_request(indio_dev);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev)
 | 
			
		||||
{
 | 
			
		||||
	struct iio_chan_spec *ch;
 | 
			
		||||
| 
						 | 
				
			
			@ -612,11 +1063,20 @@ 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 +1127,13 @@ 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 +1165,27 @@ static int stm32_dfsdm_adc_probe(struct platform_device *pdev)
 | 
			
		|||
	if (ret < 0)
 | 
			
		||||
		return ret;
 | 
			
		||||
 | 
			
		||||
	return iio_device_register(iio);
 | 
			
		||||
	ret = iio_device_register(iio);
 | 
			
		||||
	if (ret < 0)
 | 
			
		||||
		goto err_cleanup;
 | 
			
		||||
 | 
			
		||||
	dev_err(dev, "of_platform_populate\n");
 | 
			
		||||
	if (dev_data->type == DFSDM_AUDIO) {
 | 
			
		||||
		ret = of_platform_populate(np, NULL, NULL, dev);
 | 
			
		||||
		if (ret < 0) {
 | 
			
		||||
			dev_err(dev, "Failed to find an audio DAI\n");
 | 
			
		||||
			goto err_unregister;
 | 
			
		||||
		}
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	return 0;
 | 
			
		||||
 | 
			
		||||
err_unregister:
 | 
			
		||||
	iio_device_unregister(iio);
 | 
			
		||||
err_cleanup:
 | 
			
		||||
	stm32_dfsdm_dma_release(iio);
 | 
			
		||||
 | 
			
		||||
	return ret;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static int stm32_dfsdm_adc_remove(struct platform_device *pdev)
 | 
			
		||||
| 
						 | 
				
			
			@ -708,7 +1193,10 @@ static int stm32_dfsdm_adc_remove(struct platform_device *pdev)
 | 
			
		|||
	struct stm32_dfsdm_adc *adc = platform_get_drvdata(pdev);
 | 
			
		||||
	struct iio_dev *indio_dev = iio_priv_to_dev(adc);
 | 
			
		||||
 | 
			
		||||
	if (adc->dev_data->type == DFSDM_AUDIO)
 | 
			
		||||
		of_platform_depopulate(&pdev->dev);
 | 
			
		||||
	iio_device_unregister(indio_dev);
 | 
			
		||||
	stm32_dfsdm_dma_release(indio_dev);
 | 
			
		||||
 | 
			
		||||
	return 0;
 | 
			
		||||
}
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
							
								
								
									
										18
									
								
								include/linux/iio/adc/stm32-dfsdm-adc.h
									
									
									
									
									
										Normal file
									
								
							
							
						
						
									
										18
									
								
								include/linux/iio/adc/stm32-dfsdm-adc.h
									
									
									
									
									
										Normal file
									
								
							| 
						 | 
				
			
			@ -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
 | 
			
		||||
		Loading…
	
		Reference in a new issue