| Message ID | 1513241885-32079-11-git-send-email-arnaud.pouliquen@st.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 14 Dec 2017 09:58:02 +0100 Arnaud Pouliquen <arnaud.pouliquen@st.com> wrote: > 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> Looks good ;) > --- > V8 to V9 > - Create stm32_dfsdm_dma_request > - Replace devm_of_platform_populate by of_platform_populate. > - Reorder probe and remove sequences. > > .../ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 | 16 + > drivers/iio/adc/stm32-dfsdm-adc.c | 502 ++++++++++++++++++++- > include/linux/iio/adc/stm32-dfsdm-adc.h | 18 + > 3 files changed, 529 insertions(+), 7 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..b03ca3f 100644 > --- a/drivers/iio/adc/stm32-dfsdm-adc.c > +++ b/drivers/iio/adc/stm32-dfsdm-adc.c > @@ -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, > @@ -494,11 +832,22 @@ 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 +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; > } > 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 -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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..b03ca3f 100644 --- a/drivers/iio/adc/stm32-dfsdm-adc.c +++ b/drivers/iio/adc/stm32-dfsdm-adc.c @@ -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, @@ -494,11 +832,22 @@ 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 +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; } 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
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> --- V8 to V9 - Create stm32_dfsdm_dma_request - Replace devm_of_platform_populate by of_platform_populate. - Reorder probe and remove sequences. .../ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 | 16 + drivers/iio/adc/stm32-dfsdm-adc.c | 502 ++++++++++++++++++++- include/linux/iio/adc/stm32-dfsdm-adc.h | 18 + 3 files changed, 529 insertions(+), 7 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 create mode 100644 include/linux/iio/adc/stm32-dfsdm-adc.h