| Message ID | 1510222354-15290-10-git-send-email-arnaud.pouliquen@st.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 9 Nov 2017 11:12:31 +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> A few minor points inline. I'm not sure I really 'like' the solution we've ended up with currently but if it works it will do just fine for now :) Jonathan > --- > V3 -> V4 changes: > - Merge audio implementation in stm32-dfsdm-adc.c instead of creating separate file > - Add sysfs document for exported attributes > > .../ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 | 22 + > drivers/iio/adc/stm32-dfsdm-adc.c | 517 ++++++++++++++++++++- > include/linux/iio/adc/stm32-dfsdm-adc.h | 27 ++ > 3 files changed, 562 insertions(+), 4 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..0ce5508 > --- /dev/null > +++ b/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 > @@ -0,0 +1,22 @@ > +What: /sys/bus/iio/devices/iio:deviceX/in_voltage_audio_sampling_rate > +KernelVersion: 4.14 > +Contact: arnaud.pouliquen@st.com > +Description: > + For audio purpose only. > + Used by audio driver to set/get the audio sampling rate. > + Reading returns current audio sample frequency. > + Writing value before starting conversions. I would like to see a note here on why sampling_frequency can't be used for this purpose. > + > +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 > + when DFSDM SPI input channel is in slave mode. > + if DFSDM input is SPI master > + Reading 0, > + error on writing > + If DFSDM input is SPI Slave: > + Reading returns value previously set. > + Writing value before starting conversions. I'd like a brief note here on why we might change this at runtime. > diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c > index f9419ab..f0952e26 100644 > --- a/drivers/iio/adc/stm32-dfsdm-adc.c > +++ b/drivers/iio/adc/stm32-dfsdm-adc.c > @@ -19,11 +19,15 @@ > * this program. If not, see <http://www.gnu.org/licenses/>. > */ > > +#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/platform_device.h> > @@ -32,6 +36,8 @@ > > #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)) > @@ -71,6 +77,18 @@ 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 { > @@ -364,10 +382,110 @@ int stm32_dfsdm_channel_parse_of(struct stm32_dfsdm *dfsdm, > return 0; > } > > +static ssize_t dfsdm_adc_audio_get_rate(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->sample_freq); > +} > + > +static ssize_t dfsdm_adc_audio_set_rate(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 spi_freq = adc->spi_freq; > + unsigned int sample_freq; > + int ret; > + > + ret = kstrtoint(buf, 0, &sample_freq); > + if (ret) > + return ret; > + dev_dbg(&indio_dev->dev, "Requested sample_freq :%d\n", sample_freq); > + > + if (!sample_freq) > + return -EINVAL; > + > + if (ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL) > + spi_freq = adc->dfsdm->spi_master_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, > + "Not able to find filter parameter that match!\n"); > + return ret; > + } > + adc->sample_freq = sample_freq; > + > + return len; > +} > + > +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; > +} blank line here please. > 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) > @@ -378,6 +496,24 @@ 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; > @@ -411,6 +547,241 @@ 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 const struct iio_info stm32_dfsdm_info_audio = { > + .hwfifo_set_watermark = stm32_dfsdm_set_watermark, > + .driver_module = THIS_MODULE, This has gone - now handled by macro magic... > +}; > + > +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: Buffer 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. More specifically the in kernel interfaces don't support dma cyclic buffers. We can already do them to userspace. Doesn't really matter though! > + */ > + > + 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. Please run kernel-doc over this file. I'm fairly sure this isn't quite meeting the spec... > + * > + * @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); > + > + if (iio_dev != iio_priv_to_dev(adc)) > + return -EINVAL; Same as for the case below.. > + > + 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); > + > + if (iio_dev != iio_priv_to_dev(adc)) > + return -EINVAL; I can't immediately spot why this could ever fail so we definitely need a comment here saying what it is protecting against! > + 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) > { > @@ -544,6 +915,67 @@ 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[] = { > + /* filter oversampling: Post filter oversampling ratio */ > + { > + .name = "audio_sampling_rate", > + .shared = IIO_SHARED_BY_TYPE, > + .read = dfsdm_adc_audio_get_rate, > + .write = dfsdm_adc_audio_set_rate, > + }, > + /* data_right_bit_shift : Filter output data shifting */ > + { > + .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) > { > @@ -564,7 +996,12 @@ 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; > @@ -573,6 +1010,58 @@ 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); > + 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; > + } > + > + 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; > @@ -625,10 +1114,18 @@ 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, > + }, > {} > }; > > @@ -679,8 +1176,13 @@ 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; > > /* > @@ -721,7 +1223,14 @@ 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..6885645 > --- /dev/null > +++ b/include/linux/iio/adc/stm32-dfsdm-adc.h > @@ -0,0 +1,27 @@ > +/* > + * 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>. > + * > + * License terms: GPL V2.0. > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms of the GNU General Public License version 2 as published by > + * the Free Software Foundation. > + * > + * This program is distributed in the hope that it will be useful, but > + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more > + * details. > + */ > +#ifndef STM32_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
On 11/19/2017 03:18 PM, Jonathan Cameron wrote: > On Thu, 9 Nov 2017 11:12:31 +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> > > A few minor points inline. I'm not sure I really 'like' the > solution we've ended up with currently but if it works it will > do just fine for now :) > > Jonathan > > >> --- >> V3 -> V4 changes: >> - Merge audio implementation in stm32-dfsdm-adc.c instead of creating separate file >> - Add sysfs document for exported attributes >> >> .../ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 | 22 + >> drivers/iio/adc/stm32-dfsdm-adc.c | 517 ++++++++++++++++++++- >> include/linux/iio/adc/stm32-dfsdm-adc.h | 27 ++ >> 3 files changed, 562 insertions(+), 4 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..0ce5508 >> --- /dev/null >> +++ b/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 >> @@ -0,0 +1,22 @@ >> +What: /sys/bus/iio/devices/iio:deviceX/in_voltage_audio_sampling_rate >> +KernelVersion: 4.14 >> +Contact: arnaud.pouliquen@st.com >> +Description: >> + For audio purpose only. >> + Used by audio driver to set/get the audio sampling rate. >> + Reading returns current audio sample frequency. >> + Writing value before starting conversions. > > I would like to see a note here on why sampling_frequency can't be used for > this purpose. The IIO_CHAN_INFO_SAMP_FREQ can not be used because consumer API allows only to access to ext_info attributes. An alternate is to export channel attribute functions the consumer API. - iio_read_channel_attribute (already exist) - iio_write_channel_attribute Please, tell me your preference. > >> + >> +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 >> + when DFSDM SPI input channel is in slave mode. >> + if DFSDM input is SPI master >> + Reading 0, >> + error on writing >> + If DFSDM input is SPI Slave: >> + Reading returns value previously set. >> + Writing value before starting conversions. > > I'd like a brief note here on why we might change this at runtime. Sure, i will add it, output audio sample frequency is computed from the SPI_clock bus. User can need to change it depending on the Audio frequency configured for the audio card. This configuration occurs after audio driver probing. > >> diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c >> index f9419ab..f0952e26 100644 >> --- a/drivers/iio/adc/stm32-dfsdm-adc.c >> +++ b/drivers/iio/adc/stm32-dfsdm-adc.c >> @@ -19,11 +19,15 @@ >> * this program. If not, see <http://www.gnu.org/licenses/>. >> */ >> >> +#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/platform_device.h> >> @@ -32,6 +36,8 @@ >> >> #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)) >> @@ -71,6 +77,18 @@ 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 { >> @@ -364,10 +382,110 @@ int stm32_dfsdm_channel_parse_of(struct stm32_dfsdm *dfsdm, >> return 0; >> } >> >> +static ssize_t dfsdm_adc_audio_get_rate(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->sample_freq); >> +} >> + >> +static ssize_t dfsdm_adc_audio_set_rate(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 spi_freq = adc->spi_freq; >> + unsigned int sample_freq; >> + int ret; >> + >> + ret = kstrtoint(buf, 0, &sample_freq); >> + if (ret) >> + return ret; >> + dev_dbg(&indio_dev->dev, "Requested sample_freq :%d\n", sample_freq); >> + >> + if (!sample_freq) >> + return -EINVAL; >> + >> + if (ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL) >> + spi_freq = adc->dfsdm->spi_master_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, >> + "Not able to find filter parameter that match!\n"); >> + return ret; >> + } >> + adc->sample_freq = sample_freq; >> + >> + return len; >> +} >> + >> +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; >> +} > blank line here please. > >> 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) >> @@ -378,6 +496,24 @@ 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; >> @@ -411,6 +547,241 @@ 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 const struct iio_info stm32_dfsdm_info_audio = { >> + .hwfifo_set_watermark = stm32_dfsdm_set_watermark, >> + .driver_module = THIS_MODULE, > > This has gone - now handled by macro magic... > >> +}; >> + >> +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: Buffer 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. > More specifically the in kernel interfaces don't support dma cyclic > buffers. We can already do them to userspace. Doesn't really matter > though! Ok I will change comment > >> + */ >> + >> + 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. > Please run kernel-doc over this file. I'm fairly sure this isn't > quite meeting the spec... Sorry it is not crystal clear for me, could you detail what you would mean by "I'm fairly sure this isn't quite meeting the spec.."? > >> + * >> + * @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); >> + >> + if (iio_dev != iio_priv_to_dev(adc)) >> + return -EINVAL; > Same as for the case below.. > >> + >> + 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); >> + >> + if (iio_dev != iio_priv_to_dev(adc)) >> + return -EINVAL; > I can't immediately spot why this could ever fail so we definitely > need a comment here saying what it is protecting against! You're right , it is over-protection, i will suppress it Thanks Arnaud > >> + 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) >> { >> @@ -544,6 +915,67 @@ 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[] = { >> + /* filter oversampling: Post filter oversampling ratio */ >> + { >> + .name = "audio_sampling_rate", >> + .shared = IIO_SHARED_BY_TYPE, >> + .read = dfsdm_adc_audio_get_rate, >> + .write = dfsdm_adc_audio_set_rate, >> + }, >> + /* data_right_bit_shift : Filter output data shifting */ >> + { >> + .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) >> { >> @@ -564,7 +996,12 @@ 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; >> @@ -573,6 +1010,58 @@ 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); >> + 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; >> + } >> + >> + 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; >> @@ -625,10 +1114,18 @@ 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, >> + }, >> {} >> }; >> >> @@ -679,8 +1176,13 @@ 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; >> >> /* >> @@ -721,7 +1223,14 @@ 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..6885645 >> --- /dev/null >> +++ b/include/linux/iio/adc/stm32-dfsdm-adc.h >> @@ -0,0 +1,27 @@ >> +/* >> + * 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>. >> + * >> + * License terms: GPL V2.0. >> + * >> + * This program is free software; you can redistribute it and/or modify it >> + * under the terms of the GNU General Public License version 2 as published by >> + * the Free Software Foundation. >> + * >> + * This program is distributed in the hope that it will be useful, but >> + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or >> + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more >> + * details. >> + */ >> +#ifndef STM32_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 >
On Fri, 24 Nov 2017 15:52:26 +0100 Arnaud Pouliquen <arnaud.pouliquen@st.com> wrote: > On 11/19/2017 03:18 PM, Jonathan Cameron wrote: > > On Thu, 9 Nov 2017 11:12:31 +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> > > > > A few minor points inline. I'm not sure I really 'like' the > > solution we've ended up with currently but if it works it will > > do just fine for now :) > > > > Jonathan > > > > > >> --- > >> V3 -> V4 changes: > >> - Merge audio implementation in stm32-dfsdm-adc.c instead of creating separate file > >> - Add sysfs document for exported attributes > >> > >> .../ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 | 22 + > >> drivers/iio/adc/stm32-dfsdm-adc.c | 517 ++++++++++++++++++++- > >> include/linux/iio/adc/stm32-dfsdm-adc.h | 27 ++ > >> 3 files changed, 562 insertions(+), 4 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..0ce5508 > >> --- /dev/null > >> +++ b/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 > >> @@ -0,0 +1,22 @@ > >> +What: /sys/bus/iio/devices/iio:deviceX/in_voltage_audio_sampling_rate > >> +KernelVersion: 4.14 > >> +Contact: arnaud.pouliquen@st.com > >> +Description: > >> + For audio purpose only. > >> + Used by audio driver to set/get the audio sampling rate. > >> + Reading returns current audio sample frequency. > >> + Writing value before starting conversions. > > > > I would like to see a note here on why sampling_frequency can't be used for > > this purpose. > The IIO_CHAN_INFO_SAMP_FREQ can not be used because consumer API allows > only to access to ext_info attributes. > An alternate is to export channel attribute functions the consumer API. > - iio_read_channel_attribute (already exist) > - iio_write_channel_attribute Yes - add these please. Just not been a usecase before for the general write. > > Please, tell me your preference. <snip> > >> +/** > >> + * stm32_dfsdm_get_buff_cb - register a callback > >> + * that will be called when DMA transfer period is achieved. > > Please run kernel-doc over this file. I'm fairly sure this isn't > > quite meeting the spec... > Sorry it is not crystal clear for me, could you detail what you would > mean by > "I'm fairly sure this isn't quite meeting the spec.."? I don't think it lets you have multiple lines for the short description IIRC. Not sure about the indented function parameters.. Might be new since I last looked! > > > > >> + * > >> + * @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 > >> + */
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..0ce5508 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 @@ -0,0 +1,22 @@ +What: /sys/bus/iio/devices/iio:deviceX/in_voltage_audio_sampling_rate +KernelVersion: 4.14 +Contact: arnaud.pouliquen@st.com +Description: + For audio purpose only. + Used by audio driver to set/get the audio sampling rate. + Reading returns current audio sample frequency. + Writing value before starting conversions. + +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 + when DFSDM SPI input channel is in slave mode. + if DFSDM input is SPI master + Reading 0, + error on writing + If DFSDM input is SPI Slave: + Reading returns value previously set. + Writing value before starting conversions. diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c index f9419ab..f0952e26 100644 --- a/drivers/iio/adc/stm32-dfsdm-adc.c +++ b/drivers/iio/adc/stm32-dfsdm-adc.c @@ -19,11 +19,15 @@ * this program. If not, see <http://www.gnu.org/licenses/>. */ +#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/platform_device.h> @@ -32,6 +36,8 @@ #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)) @@ -71,6 +77,18 @@ 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 { @@ -364,10 +382,110 @@ int stm32_dfsdm_channel_parse_of(struct stm32_dfsdm *dfsdm, return 0; } +static ssize_t dfsdm_adc_audio_get_rate(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->sample_freq); +} + +static ssize_t dfsdm_adc_audio_set_rate(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 spi_freq = adc->spi_freq; + unsigned int sample_freq; + int ret; + + ret = kstrtoint(buf, 0, &sample_freq); + if (ret) + return ret; + dev_dbg(&indio_dev->dev, "Requested sample_freq :%d\n", sample_freq); + + if (!sample_freq) + return -EINVAL; + + if (ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL) + spi_freq = adc->dfsdm->spi_master_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, + "Not able to find filter parameter that match!\n"); + return ret; + } + adc->sample_freq = sample_freq; + + return len; +} + +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) @@ -378,6 +496,24 @@ 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; @@ -411,6 +547,241 @@ 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 const struct iio_info stm32_dfsdm_info_audio = { + .hwfifo_set_watermark = stm32_dfsdm_set_watermark, + .driver_module = THIS_MODULE, +}; + +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: Buffer 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); + + if (iio_dev != iio_priv_to_dev(adc)) + return -EINVAL; + + 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); + + if (iio_dev != iio_priv_to_dev(adc)) + return -EINVAL; + 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) { @@ -544,6 +915,67 @@ 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[] = { + /* filter oversampling: Post filter oversampling ratio */ + { + .name = "audio_sampling_rate", + .shared = IIO_SHARED_BY_TYPE, + .read = dfsdm_adc_audio_get_rate, + .write = dfsdm_adc_audio_set_rate, + }, + /* data_right_bit_shift : Filter output data shifting */ + { + .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) { @@ -564,7 +996,12 @@ 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; @@ -573,6 +1010,58 @@ 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); + 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; + } + + 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; @@ -625,10 +1114,18 @@ 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, + }, {} }; @@ -679,8 +1176,13 @@ 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; /* @@ -721,7 +1223,14 @@ 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..6885645 --- /dev/null +++ b/include/linux/iio/adc/stm32-dfsdm-adc.h @@ -0,0 +1,27 @@ +/* + * 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>. + * + * License terms: GPL V2.0. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more + * details. + */ +#ifndef STM32_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> --- V3 -> V4 changes: - Merge audio implementation in stm32-dfsdm-adc.c instead of creating separate file - Add sysfs document for exported attributes .../ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 | 22 + drivers/iio/adc/stm32-dfsdm-adc.c | 517 ++++++++++++++++++++- include/linux/iio/adc/stm32-dfsdm-adc.h | 27 ++ 3 files changed, 562 insertions(+), 4 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 create mode 100644 include/linux/iio/adc/stm32-dfsdm-adc.h