Add DFSDM driver to handle PDM audio microphones. Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxx> --- drivers/iio/adc/Kconfig | 13 + drivers/iio/adc/Makefile | 1 + drivers/iio/adc/stm32-dfsdm-audio.c | 720 ++++++++++++++++++++++++++++++ include/linux/iio/adc/stm32-dfsdm-audio.h | 41 ++ 4 files changed, 775 insertions(+) create mode 100644 drivers/iio/adc/stm32-dfsdm-audio.c create mode 100644 include/linux/iio/adc/stm32-dfsdm-audio.h diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 3e0eb11..c108933 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -478,6 +478,19 @@ config STM32_DFSDM_ADC This driver can also be built as a module. If so, the module will be called stm32-dfsdm-adc. +config STM32_DFSDM_AUDIO + tristate "STMicroelectronics STM32 dfsdm audio + depends on (ARCH_STM32 && OF) || COMPILE_TEST + select STM32_DFSDM_CORE + select REGMAP_MMIO + select IIO_BUFFER_DMAENGINE + help + Select this option to support Audio PDM micophone for + STMicroelectronics STM32 digital filter for sigma delta converter. + + This driver can also be built as a module. If so, the module + will be called stm32-dfsdm-audio. + config STX104 tristate "Apex Embedded Systems STX104 driver" depends on X86 && ISA_BUS_API diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index 161f271..79f975d 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -44,6 +44,7 @@ obj-$(CONFIG_STX104) += stx104.o obj-$(CONFIG_STM32_ADC_CORE) += stm32-adc-core.o obj-$(CONFIG_STM32_ADC) += stm32-adc.o obj-$(CONFIG_STM32_DFSDM_ADC) += stm32-dfsdm-adc.o +obj-$(CONFIG_STM32_DFSDM_AUDIO) += stm32-dfsdm-audio.o obj-$(CONFIG_STM32_DFSDM_CORE) += stm32-dfsdm-core.o obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o diff --git a/drivers/iio/adc/stm32-dfsdm-audio.c b/drivers/iio/adc/stm32-dfsdm-audio.c new file mode 100644 index 0000000..115ef8f --- /dev/null +++ b/drivers/iio/adc/stm32-dfsdm-audio.c @@ -0,0 +1,720 @@ +/* + * This file is the ADC part of of the STM32 DFSDM driver + * + * Copyright (C) 2017, STMicroelectronics - All Rights Reserved + * Author: Arnaud Pouliquen <arnaud.pouliquen@xxxxxx>. + * + * License type: GPLv2 + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. + * See the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/slab.h> + +#include <linux/iio/buffer.h> +#include <linux/iio/hw_consumer.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/trigger.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> + +#include "stm32-dfsdm.h" + +#define DFSDM_DMA_BUFFER_SIZE (4 * PAGE_SIZE) + +struct stm32_dfsdm_audio { + struct stm32_dfsdm *dfsdm; + unsigned int fl_id; + unsigned int ch_id; + unsigned int spi_freq; /* SPI bus clock frequency */ + unsigned int sample_freq; /* Sample frequency after filter decimation */ + + 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; + + int (*cb)(const void *data, size_t size, void *cb_priv); + void *cb_priv; +}; + +const char *stm32_dfsdm_spi_trigger = DFSDM_SPI_TRIGGER_NAME; + +static ssize_t dfsdm_audio_get_rate(struct iio_dev *indio_dev, uintptr_t priv, + const struct iio_chan_spec *chan, char *buf) +{ + struct stm32_dfsdm_audio *pdmc = iio_priv(indio_dev); + + return snprintf(buf, PAGE_SIZE, "%d\n", pdmc->sample_freq); +} + +static ssize_t dfsdm_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_audio *pdmc = iio_priv(indio_dev); + struct stm32_dfsdm_filter *fl = &pdmc->dfsdm->fl_list[pdmc->fl_id]; + struct stm32_dfsdm_channel *ch = &pdmc->dfsdm->ch_list[pdmc->ch_id]; + unsigned int spi_freq = pdmc->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 = pdmc->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; + } + pdmc->sample_freq = sample_freq; + + return len; +} + +static ssize_t dfsdm_audio_get_spiclk(struct iio_dev *indio_dev, uintptr_t priv, + const struct iio_chan_spec *chan, + char *buf) +{ + struct stm32_dfsdm_audio *pdmc = iio_priv(indio_dev); + + return snprintf(buf, PAGE_SIZE, "%d\n", pdmc->spi_freq); +} + +static ssize_t dfsdm_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_audio *pdmc = iio_priv(indio_dev); + struct stm32_dfsdm_filter *fl = &pdmc->dfsdm->fl_list[pdmc->fl_id]; + struct stm32_dfsdm_channel *ch = &pdmc->dfsdm->ch_list[pdmc->ch_id]; + unsigned int sample_freq = pdmc->sample_freq; + unsigned int spi_freq; + int ret; + + /* 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; + + dev_dbg(&indio_dev->dev, "Requested frequency :%d\n", spi_freq); + 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; + } + } + pdmc->spi_freq = spi_freq; + + return len; +} + +/* + * 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_ext_info[] = { + /* filter oversampling: Post filter oversampling ratio */ + { + .name = "audio_sampling_rate", + .shared = IIO_SHARED_BY_TYPE, + .read = dfsdm_audio_get_rate, + .write = dfsdm_audio_set_rate, + }, + /* data_right_bit_shift : Filter output data shifting */ + { + .name = "spi_clk_freq", + .shared = IIO_SHARED_BY_TYPE, + .read = dfsdm_audio_get_spiclk, + .write = dfsdm_audio_set_spiclk, + }, + {}, +}; + +static int stm32_dfsdm_start_conv(struct stm32_dfsdm_audio *pdmc, bool single) +{ + struct regmap *regmap = pdmc->dfsdm->regmap; + int ret; + + ret = stm32_dfsdm_start_dfsdm(pdmc->dfsdm); + if (ret < 0) + return ret; + + ret = stm32_dfsdm_start_channel(pdmc->dfsdm, pdmc->ch_id); + if (ret < 0) + goto stop_dfsdm; + + ret = stm32_dfsdm_filter_configure(pdmc->dfsdm, pdmc->fl_id, + pdmc->ch_id); + if (ret < 0) + goto stop_channels; + + /* Enable DMA transfer*/ + ret = regmap_update_bits(regmap, DFSDM_CR1(pdmc->fl_id), + DFSDM_CR1_RDMAEN_MASK, DFSDM_CR1_RDMAEN(1)); + if (ret < 0) + return ret; + + /* Enable conversion triggered by SPI clock*/ + ret = regmap_update_bits(regmap, DFSDM_CR1(pdmc->fl_id), + DFSDM_CR1_RCONT_MASK, DFSDM_CR1_RCONT(1)); + if (ret < 0) + return ret; + + ret = stm32_dfsdm_start_filter(pdmc->dfsdm, pdmc->fl_id); + if (ret < 0) + goto stop_channels; + + return 0; + +stop_channels: + stm32_dfsdm_stop_channel(pdmc->dfsdm, pdmc->fl_id); +stop_dfsdm: + stm32_dfsdm_stop_dfsdm(pdmc->dfsdm); + + return ret; +} + +static void stm32_dfsdm_stop_conv(struct stm32_dfsdm_audio *pdmc) +{ + stm32_dfsdm_stop_filter(pdmc->dfsdm, pdmc->fl_id); + + stm32_dfsdm_stop_channel(pdmc->dfsdm, pdmc->ch_id); + + stm32_dfsdm_stop_dfsdm(pdmc->dfsdm); +} + +static int stm32_dfsdm_set_watermark(struct iio_dev *indio_dev, + unsigned int val) +{ + struct stm32_dfsdm_audio *pdmc = 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))); + pdmc->buf_sz = watermark * 2; + + return 0; +} + +int stm32_dfsdm_validate_trigger(struct iio_dev *indio_dev, + struct iio_trigger *trig) +{ + if (!strcmp(stm32_dfsdm_spi_trigger, trig->name)) + return 0; + + return -EINVAL; +} + +static const struct iio_info stm32_dfsdm_info_pdmc = { + .hwfifo_set_watermark = stm32_dfsdm_set_watermark, + .driver_module = THIS_MODULE, + .validate_trigger = stm32_dfsdm_validate_trigger, +}; + +static irqreturn_t stm32_dfsdm_irq(int irq, void *arg) +{ + struct stm32_dfsdm_audio *pdmc = arg; + struct iio_dev *indio_dev = iio_priv_to_dev(pdmc); + struct regmap *regmap = pdmc->dfsdm->regmap; + unsigned int status; + + regmap_read(regmap, DFSDM_ISR(pdmc->fl_id), &status); + + if (status & DFSDM_ISR_ROVRF_MASK) { + dev_err(&indio_dev->dev, "Unexpected Conversion overflow\n"); + regmap_update_bits(regmap, DFSDM_ICR(pdmc->fl_id), + DFSDM_ICR_CLRROVRF_MASK, + DFSDM_ICR_CLRROVRF_MASK); + } + + return IRQ_HANDLED; +} + +static unsigned int stm32_dfsdm_audio_avail_data(struct stm32_dfsdm_audio *pdmc) +{ + struct dma_tx_state state; + enum dma_status status; + + status = dmaengine_tx_status(pdmc->dma_chan, + pdmc->dma_chan->cookie, + &state); + if (status == DMA_IN_PROGRESS) { + /* Residue is size in bytes from end of buffer */ + unsigned int i = pdmc->buf_sz - state.residue; + unsigned int size; + + /* Return available bytes */ + if (i >= pdmc->bufi) + size = i - pdmc->bufi; + else + size = pdmc->buf_sz + i - pdmc->bufi; + + return size; + } + + return 0; +} + +static void stm32_dfsdm_audio_dma_buffer_done(void *data) +{ + struct iio_dev *indio_dev = data; + + iio_trigger_poll_chained(indio_dev->trig); +} + +static int stm32_dfsdm_audio_dma_start(struct iio_dev *indio_dev) +{ + struct stm32_dfsdm_audio *pdmc = iio_priv(indio_dev); + struct dma_async_tx_descriptor *desc; + dma_cookie_t cookie; + int ret; + + if (!pdmc->dma_chan) + return -EINVAL; + + dev_dbg(&indio_dev->dev, "%s size=%d watermark=%d\n", __func__, + pdmc->buf_sz, pdmc->buf_sz / 2); + + /* Prepare a DMA cyclic transaction */ + desc = dmaengine_prep_dma_cyclic(pdmc->dma_chan, + pdmc->dma_buf, + pdmc->buf_sz, pdmc->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(pdmc->dma_chan); + return ret; + } + + /* Issue pending DMA requests */ + dma_async_issue_pending(pdmc->dma_chan); + + return 0; +} + +static int stm32_dfsdm_postenable(struct iio_dev *indio_dev) +{ + struct stm32_dfsdm_audio *pdmc = iio_priv(indio_dev); + int ret; + + dev_dbg(&indio_dev->dev, "%s\n", __func__); + /* Reset pdmc buffer index */ + pdmc->bufi = 0; + + ret = stm32_dfsdm_start_conv(pdmc, false); + if (ret) { + dev_err(&indio_dev->dev, "Can't start conversion\n"); + return ret; + } + + ret = stm32_dfsdm_audio_dma_start(indio_dev); + if (ret) { + dev_err(&indio_dev->dev, "Can't start DMA\n"); + goto err_stop_conv; + } + + ret = iio_triggered_buffer_postenable(indio_dev); + if (ret < 0) { + dev_err(&indio_dev->dev, "%s :%d\n", __func__, __LINE__); + goto err_stop_dma; + } + + return 0; + +err_stop_dma: + if (pdmc->dma_chan) + dmaengine_terminate_all(pdmc->dma_chan); +err_stop_conv: + stm32_dfsdm_stop_conv(pdmc); + + return ret; +} + +static int stm32_dfsdm_predisable(struct iio_dev *indio_dev) +{ + struct stm32_dfsdm_audio *pdmc = iio_priv(indio_dev); + int ret; + + dev_dbg(&indio_dev->dev, "%s\n", __func__); + ret = iio_triggered_buffer_predisable(indio_dev); + if (ret < 0) + dev_err(&indio_dev->dev, "Predisable failed\n"); + + if (pdmc->dma_chan) + dmaengine_terminate_all(pdmc->dma_chan); + + stm32_dfsdm_stop_conv(pdmc); + + return 0; +} + +static const struct iio_buffer_setup_ops stm32_dfsdm_buffer_setup_ops = { + .postenable = &stm32_dfsdm_postenable, + .predisable = &stm32_dfsdm_predisable, +}; + +static irqreturn_t stm32_dfsdm_audio_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct stm32_dfsdm_audio *pdmc = iio_priv(indio_dev); + size_t old_pos; + int available = stm32_dfsdm_audio_avail_data(pdmc); + + /* + * Buffer interface is not support cyclic DMA buffer,and offer only + * an interface to push data samples per samples. + * For this reason iio_push_to_buffers_with_timestamp in not used + * and interface is hacked 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__, + pdmc->bufi, available); + old_pos = pdmc->bufi; + while (available >= indio_dev->scan_bytes) { + u32 *buffer = (u32 *)&pdmc->rx_buf[pdmc->bufi]; + + /* Mask 8 LSB that contains the channel ID */ + *buffer &= 0xFFFFFF00; + available -= indio_dev->scan_bytes; + pdmc->bufi += indio_dev->scan_bytes; + if (pdmc->bufi >= pdmc->buf_sz) { + if (pdmc->cb) + pdmc->cb(&pdmc->rx_buf[old_pos], + pdmc->buf_sz - old_pos, pdmc->cb_priv); + pdmc->bufi = 0; + old_pos = 0; + } + } + if (pdmc->cb) + pdmc->cb(&pdmc->rx_buf[old_pos], pdmc->bufi - old_pos, + pdmc->cb_priv); + + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + +/** + * 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_audio *pdmc; + + if (!iio_dev) + return -EINVAL; + pdmc = iio_priv(iio_dev); + + if (iio_dev != iio_priv_to_dev(pdmc)) + return -EINVAL; + + pdmc->cb = cb; + pdmc->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_audio *pdmc; + + if (!iio_dev) + return -EINVAL; + pdmc = iio_priv(iio_dev); + + if (iio_dev != iio_priv_to_dev(pdmc)) + return -EINVAL; + pdmc->cb = NULL; + pdmc->cb_priv = NULL; + + return 0; +} +EXPORT_SYMBOL_GPL(stm32_dfsdm_release_buff_cb); + +static int stm32_dfsdm_audio_chan_init(struct iio_dev *indio_dev) +{ + struct iio_chan_spec *ch; + struct stm32_dfsdm_audio *pdmc = iio_priv(indio_dev); + int ret; + + ch = devm_kzalloc(&indio_dev->dev, sizeof(*ch), GFP_KERNEL); + if (!ch) + return -ENOMEM; + + ret = stm32_dfsdm_channel_parse_of(pdmc->dfsdm, indio_dev, ch, 0); + if (ret < 0) + return ret; + + ch->type = IIO_VOLTAGE; + ch->indexed = 1; + ch->scan_index = 0; + ch->ext_info = dfsdm_adc_ext_info; + + ch->scan_type.sign = 's'; + ch->scan_type.realbits = 24; + ch->scan_type.storagebits = 32; + + pdmc->ch_id = ch->channel; + ret = stm32_dfsdm_chan_configure(pdmc->dfsdm, + &pdmc->dfsdm->ch_list[ch->channel]); + + indio_dev->num_channels = 1; + indio_dev->channels = ch; + + return ret; +} + +static const struct of_device_id stm32_dfsdm_audio_match[] = { + { .compatible = "st,stm32-dfsdm-audio"}, + {} +}; + +static int stm32_dfsdm_audio_dma_request(struct iio_dev *indio_dev) +{ + struct stm32_dfsdm_audio *pdmc = iio_priv(indio_dev); + struct dma_slave_config config; + int ret; + + pdmc->dma_chan = dma_request_slave_channel(&indio_dev->dev, "rx"); + if (!pdmc->dma_chan) + return -EINVAL; + + pdmc->rx_buf = dma_alloc_coherent(pdmc->dma_chan->device->dev, + DFSDM_DMA_BUFFER_SIZE, + &pdmc->dma_buf, GFP_KERNEL); + if (!pdmc->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)pdmc->dfsdm->phys_base; + config.src_addr += DFSDM_RDATAR(pdmc->fl_id); + config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; + + ret = dmaengine_slave_config(pdmc->dma_chan, &config); + if (ret) + goto err_free; + + return 0; + +err_free: + dma_free_coherent(pdmc->dma_chan->device->dev, DFSDM_DMA_BUFFER_SIZE, + pdmc->rx_buf, pdmc->dma_buf); +err_release: + dma_release_channel(pdmc->dma_chan); + + return ret; +} + +static int stm32_dfsdm_audio_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct stm32_dfsdm_audio *pdmc; + struct device_node *np = dev->of_node; + struct iio_dev *iio; + char *name; + int ret, irq, val; + + iio = devm_iio_device_alloc(dev, sizeof(*pdmc)); + if (IS_ERR(iio)) { + dev_err(dev, "%s: Failed to allocate IIO\n", __func__); + return PTR_ERR(iio); + } + + pdmc = iio_priv(iio); + if (IS_ERR(pdmc)) { + dev_err(dev, "%s: Failed to allocate ADC\n", __func__); + return PTR_ERR(pdmc); + } + pdmc->dfsdm = dev_get_drvdata(dev->parent); + + iio->name = np->name; + iio->dev.parent = dev; + iio->dev.of_node = np; + iio->info = &stm32_dfsdm_info_pdmc; + iio->modes = INDIO_DIRECT_MODE; + + platform_set_drvdata(pdev, pdmc); + + ret = of_property_read_u32(dev->of_node, "reg", &pdmc->fl_id); + if (ret != 0) { + dev_err(dev, "Missing reg property\n"); + return -EINVAL; + } + + name = kzalloc(sizeof("dfsdm-pdm0"), GFP_KERNEL); + if (!name) + return -ENOMEM; + snprintf(name, sizeof("dfsdm-pdm0"), "dfsdm-pdm%d", pdmc->fl_id); + iio->name = name; + + /* + * In a first step IRQs generated for channels are not treated. + * So IRQ associated to filter instance 0 is dedicated to the Filter 0. + */ + irq = platform_get_irq(pdev, 0); + ret = devm_request_irq(dev, irq, stm32_dfsdm_irq, + 0, pdev->name, pdmc); + if (ret < 0) { + dev_err(dev, "Failed to request IRQ\n"); + return ret; + } + + ret = of_property_read_u32(dev->of_node, "st,filter-order", &val); + if (ret < 0) { + dev_err(dev, "Failed to set filter order\n"); + return ret; + } + pdmc->dfsdm->fl_list[pdmc->fl_id].ford = val; + + ret = of_property_read_u32(dev->of_node, "st,filter0-sync", &val); + if (!ret) + pdmc->dfsdm->fl_list[pdmc->fl_id].sync_mode = val; + + ret = stm32_dfsdm_audio_chan_init(iio); + if (ret < 0) + return ret; + + ret = stm32_dfsdm_audio_dma_request(iio); + if (ret) { + dev_err(&pdev->dev, "DMA request failed\n"); + return ret; + } + + iio->modes |= INDIO_BUFFER_SOFTWARE; + + ret = iio_triggered_buffer_setup(iio, + &iio_pollfunc_store_time, + &stm32_dfsdm_audio_trigger_handler, + &stm32_dfsdm_buffer_setup_ops); + if (ret) { + dev_err(&pdev->dev, "Buffer setup failed\n"); + goto err_dma_disable; + } + + ret = iio_device_register(iio); + if (ret) { + dev_err(&pdev->dev, "IIO dev register failed\n"); + goto err_buffer_cleanup; + } + + return 0; + +err_buffer_cleanup: + iio_triggered_buffer_cleanup(iio); + +err_dma_disable: + if (pdmc->dma_chan) { + dma_free_coherent(pdmc->dma_chan->device->dev, + DFSDM_DMA_BUFFER_SIZE, + pdmc->rx_buf, pdmc->dma_buf); + dma_release_channel(pdmc->dma_chan); + } + + return ret; +} + +static int stm32_dfsdm_audio_remove(struct platform_device *pdev) +{ + struct stm32_dfsdm_audio *pdmc = platform_get_drvdata(pdev); + struct iio_dev *iio = iio_priv_to_dev(pdmc); + + iio_device_unregister(iio); + + return 0; +} + +static struct platform_driver stm32_dfsdm_audio_driver = { + .driver = { + .name = "stm32-dfsdm-audio", + .of_match_table = stm32_dfsdm_audio_match, + }, + .probe = stm32_dfsdm_audio_probe, + .remove = stm32_dfsdm_audio_remove, +}; +module_platform_driver(stm32_dfsdm_audio_driver); + +MODULE_DESCRIPTION("STM32 sigma delta converter for PDM microphone"); +MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@xxxxxx>"); +MODULE_LICENSE("GPL v2"); diff --git a/include/linux/iio/adc/stm32-dfsdm-audio.h b/include/linux/iio/adc/stm32-dfsdm-audio.h new file mode 100644 index 0000000..9b41b28 --- /dev/null +++ b/include/linux/iio/adc/stm32-dfsdm-audio.h @@ -0,0 +1,41 @@ +/* + * 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@xxxxxx>. + * + * License terms: GPL V2.0. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more + * details. + */ +#ifndef STM32_DFSDM_AUDIO_H +#define STM32_DFSDM_AUDIO_H + +/** + * stm32_dfsdm_get_buff_cb() - register callback for capture buffer period. + * @dev: Pointer to client device. + * @indio_dev: Device on which the channel exists. + * @cb: Callback function. + * @data: pointer to data buffer + * @size: size of the data buffer in bytes + * @private: Private data passed to callback. + * + */ +int stm32_dfsdm_get_buff_cb(struct iio_dev *iio_dev, + int (*cb)(const void *data, size_t size, + void *private), + void *private); +/** + * stm32_dfsdm_get_buff_cb() - release callback for capture buffer period. + * @indio_dev: Device on which the channel exists. + */ +int stm32_dfsdm_release_buff_cb(struct iio_dev *iio_dev); + +#endif -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
