On 03/25/2017 04:59 PM, Jonathan Cameron wrote: > On 20/03/17 11:29, Arnaud Pouliquen wrote: >> Please find my comments in-line >> >> Thanks and Regards, >> Arnaud >> >> On 03/19/2017 11:38 PM, Jonathan Cameron wrote: >>> On 17/03/17 14:08, Arnaud Pouliquen wrote: >>>> Add DFSDM driver to handle PDM audio microphones. >>>> >>>> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxx> >>> So key element here is that we really need to have a proper way of >>> doing DMA buffer consumers from IIO (as you said in your cover letter). >>> >>> Not entirely obvious how to do this. Would like some input from Lars >>> if possible. I'm afraid I don't have an suitable hardware to try anything >>> out on (or the time really!). This will obviously be quite different from >>> the single scan stuff you have seen is there at the moment. >> I saw 2 other drivers ti_am335x_adc.c and stm32_adc.c) that use cyclic >> DMA. I suppose that problematics are similar. Perhaps the extra >> constrains in DFSDM is the in-kernel API used to get the data. > Absolutely. Cyclic dma is becoming more and more common on SoC ADCs. > There are a few more fpga based ones in Analog devices tree as well - > most of those actually do the dma buffer route rather than pushing through > the normal buffer interface (kfifo effectively). Right now we just > don't have any means of accessing these dma buffers in kernel. > > Unlike the normal consumer interface, I doubt we'll want to do demuxing > of the stream for this sort of usecase - feels like exclusive use is more > likely. >> >>> >>> Whether this whole approach makes sense vs doing the dma in the alsa driver >>> isn't clear to me. >>> >>> On the plus side, presumably we'll get love dma ADC support for free >>> as part of doing it this way ;) >>> >>> It's been a while since I looked at the IIO dma buffer stuff at all. Will >>> try and refresh my memory sometime this week. >> >> Ok, i will wait your feedback (and Lars's one) before updating my code >> for next version. > It may well be the case that it will take us sometime (when I say us, I mean > you and Lars ;) to pin down how to do dma buffer consumers, so it may be > a case of taking the driver in a state close to the current one with the > intent to switch to a generic way of handling it later. I had a short discussion with Lars on IIO IRC, seems that he also does not see a straightforward solution for this IP. The Fact that audio part is in a separate file should help to rework it in a generic way. So i will propose a V4 for upstream, integrating discussed fixes. Thanks Arnaud > > As long as bindings and userspace don't change we can of course mess with > anything we like. > > Jonathan >>> >>> Jonathan >>>> --- >>>> 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); >>> This shouldn't be going through the trigger infrastructure at all really. >>> I'm not 100% sure what doing so is gaining you... >> Yes i will clean trigger part and call directly the ASoC callback here. >>>> +} >>>> + >>>> +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) >>>> +{ >>> OK. So now I kind of understand what the trigger provided in the adc driver >>> was about. hmm. Triggers are supposed to be per sample so this is indeed >>> a hack. We need fullblown DMA buffer consumers to do this right. >> Yes exactly. >>> >>> Probably best person to comment on that is Lars. >>>> + 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); >>> Same as in the other driver. Can just use the devm_iio_device_register >>> version and drop remove. >> oops missing the previous comment... sorry. >>>> + >>>> + 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 >>>> >>> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-iio" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
