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@xxxxxx> --- 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@xxxxxx +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@xxxxxx +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@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_ADC_H +#define STM32_DFSDM_ADC_H + +int stm32_dfsdm_get_buff_cb(struct iio_dev *iio_dev, + int (*cb)(const void *data, size_t size, + void *private), + void *private); +int stm32_dfsdm_release_buff_cb(struct iio_dev *iio_dev); + +#endif -- 2.7.4 -- 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
