Add DFSDM driver to handle sigma delta ADC.

Signed-off-by: Arnaud Pouliquen arnaud.pouliquen@st.com --- drivers/iio/adc/Kconfig | 13 + drivers/iio/adc/Makefile | 1 + drivers/iio/adc/stm32-dfsdm-adc.c | 741 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 755 insertions(+) create mode 100644 drivers/iio/adc/stm32-dfsdm-adc.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index b729ae0..98ca30b 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -677,6 +677,19 @@ config STM32_DFSDM_CORE This driver can also be built as a module. If so, the module will be called stm32-dfsdm-core.

+config STM32_DFSDM_ADC + tristate "STMicroelectronics STM32 dfsdm adc" + depends on (ARCH_STM32 && OF) || COMPILE_TEST + select STM32_DFSDM_CORE + select REGMAP_MMIO + select IIO_BUFFER_HW_CONSUMER + help + Select this option to support ADCSigma delta modulator 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-adc. + config STX104 tristate "Apex Embedded Systems STX104 driver" depends on PC104 && X86 && ISA_BUS_API diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index b52d0a0..c4f5d15 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -64,6 +64,7 @@ obj-$(CONFIG_SUN4I_GPADC) += sun4i-gpadc-iio.o obj-$(CONFIG_STM32_ADC_CORE) += stm32-adc-core.o obj-$(CONFIG_STM32_ADC) += stm32-adc.o obj-$(CONFIG_STM32_DFSDM_CORE) += stm32-dfsdm-core.o +obj-$(CONFIG_STM32_DFSDM_ADC) += stm32-dfsdm-adc.o obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o obj-$(CONFIG_TI_ADC084S021) += ti-adc084s021.o diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c new file mode 100644 index 0000000..f9419ab --- /dev/null +++ b/drivers/iio/adc/stm32-dfsdm-adc.c @@ -0,0 +1,741 @@ +/* + * This file is the ADC part of the STM32 DFSDM driver + * + * Copyright (C) 2017, STMicroelectronics - All Rights Reserved + * Author: Arnaud Pouliquen arnaud.pouliquen@st.com. + * + * License type: 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. + * + * 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/interrupt.h> +#include <linux/iio/buffer.h> +#include <linux/iio/hw-consumer.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/slab.h> + +#include "stm32-dfsdm.h" + +/* Conversion timeout */ +#define DFSDM_TIMEOUT_US 100000 +#define DFSDM_TIMEOUT (msecs_to_jiffies(DFSDM_TIMEOUT_US / 1000)) + +/* Oversampling attribute default */ +#define DFSDM_DEFAULT_OVERSAMPLING 100 + +/* Oversampling max values */ +#define DFSDM_MAX_INT_OVERSAMPLING 256 +#define DFSDM_MAX_FL_OVERSAMPLING 1024 + +/* Max sample resolutions */ +#define DFSDM_MAX_RES BIT(31) +#define DFSDM_DATA_RES BIT(23) + +enum sd_converter_type { + DFSDM_AUDIO, + DFSDM_IIO, +}; + +struct stm32_dfsdm_dev_data { + int type; + int (*init)(struct iio_dev *indio_dev); + unsigned int num_channels; + const struct regmap_config *regmap_cfg; +}; + +struct stm32_dfsdm_adc { + struct stm32_dfsdm *dfsdm; + const struct stm32_dfsdm_dev_data *dev_data; + unsigned int fl_id; + unsigned int ch_id; + + /* ADC specific */ + unsigned int oversamp; + struct iio_hw_consumer *hwc; + struct completion completion; + u32 *buffer; + +}; + +struct stm32_dfsdm_str2field { + const char *name; + unsigned int val; +}; + +/* DFSDM channel serial interface type */ +static const struct stm32_dfsdm_str2field stm32_dfsdm_chan_type[] = { + { "SPI_R", 0 }, /* SPI with data on rising edge */ + { "SPI_F", 1 }, /* SPI with data on falling edge */ + { "MANCH_R", 2 }, /* Manchester codec, rising edge = logic 0 */ + { "MANCH_F", 3 }, /* Manchester codec, falling edge = logic 1 */ + {}, +}; + +/* DFSDM channel clock source */ +static const struct stm32_dfsdm_str2field stm32_dfsdm_chan_src[] = { + /* External SPI clock (CLKIN x) */ + { "CLKIN", DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL }, + /* Internal SPI clock (CLKOUT) */ + { "CLKOUT", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL }, + /* Internal SPI clock divided by 2 (falling edge) */ + { "CLKOUT_F", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_FALLING }, + /* Internal SPI clock divided by 2 (falling edge) */ + { "CLKOUT_R", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_RISING }, + {}, +}; + +static int stm32_dfsdm_str2val(const char *str, + const struct stm32_dfsdm_str2field *list) +{ + const struct stm32_dfsdm_str2field *p = list; + + for (p = list; p && p->name; p++) + if (!strcmp(p->name, str)) + return p->val; + + return -EINVAL; +} + +static int stm32_dfsdm_set_osrs(struct stm32_dfsdm_filter *fl, + unsigned int fast, unsigned int oversamp) +{ + unsigned int i, d, fosr, iosr; + u64 res; + s64 delta; + unsigned int m = 1; /* multiplication factor */ + unsigned int p = fl->ford; /* filter order (ford) */ + + pr_debug("%s: Requested oversampling: %d\n", __func__, oversamp); + /* + * This function tries to compute filter oversampling and integrator + * oversampling, base on oversampling ratio requested by user. + * + * Decimation d depends on the filter order and the oversampling ratios. + * ford: filter order + * fosr: filter over sampling ratio + * iosr: integrator over sampling ratio + */ + if (fl->ford == DFSDM_FASTSINC_ORDER) { + m = 2; + p = 2; + } + + /* + * Look for filter and integrator oversampling ratios which allows + * to reach 24 bits data output resolution. + * Leave as soon as if exact resolution if reached. + * Otherwise the higher resolution below 32 bits is kept. + */ + for (fosr = 1; fosr <= DFSDM_MAX_FL_OVERSAMPLING; fosr++) { + for (iosr = 1; iosr <= DFSDM_MAX_INT_OVERSAMPLING; iosr++) { + if (fast) + d = fosr * iosr; + else if (fl->ford == DFSDM_FASTSINC_ORDER) + d = fosr * (iosr + 3) + 2; + else + d = fosr * (iosr - 1 + p) + p; + + if (d > oversamp) + break; + else if (d != oversamp) + continue; + /* + * Check resolution (limited to signed 32 bits) + * res <= 2^31 + * Sincx filters: + * res = m * fosr^p x iosr (with m=1, p=ford) + * FastSinc filter + * res = m * fosr^p x iosr (with m=2, p=2) + */ + res = fosr; + for (i = p - 1; i > 0; i--) { + res = res * (u64)fosr; + if (res > DFSDM_MAX_RES) + break; + } + if (res > DFSDM_MAX_RES) + continue; + res = res * (u64)m * (u64)iosr; + if (res > DFSDM_MAX_RES) + continue; + + delta = res - DFSDM_DATA_RES; + + if (res >= fl->res) { + fl->res = res; + fl->fosr = fosr; + fl->iosr = iosr; + fl->fast = fast; + pr_debug("%s: fosr = %d, iosr = %d\n", + __func__, fl->fosr, fl->iosr); + } + + if (!delta) + return 0; + } + } + + if (!fl->fosr) + return -EINVAL; + + return 0; +} + +static int stm32_dfsdm_start_channel(struct stm32_dfsdm *dfsdm, + unsigned int ch_id) +{ + return regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(ch_id), + DFSDM_CHCFGR1_CHEN_MASK, + DFSDM_CHCFGR1_CHEN(1)); +} + +static void stm32_dfsdm_stop_channel(struct stm32_dfsdm *dfsdm, + unsigned int ch_id) +{ + regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(ch_id), + DFSDM_CHCFGR1_CHEN_MASK, DFSDM_CHCFGR1_CHEN(0)); +} + +static int stm32_dfsdm_chan_configure(struct stm32_dfsdm *dfsdm, + struct stm32_dfsdm_channel *ch) +{ + unsigned int id = ch->id; + struct regmap *regmap = dfsdm->regmap; + int ret; + + ret = regmap_update_bits(regmap, DFSDM_CHCFGR1(id), + DFSDM_CHCFGR1_SITP_MASK, + DFSDM_CHCFGR1_SITP(ch->type)); + if (ret < 0) + return ret; + ret = regmap_update_bits(regmap, DFSDM_CHCFGR1(id), + DFSDM_CHCFGR1_SPICKSEL_MASK, + DFSDM_CHCFGR1_SPICKSEL(ch->src)); + if (ret < 0) + return ret; + return regmap_update_bits(regmap, DFSDM_CHCFGR1(id), + DFSDM_CHCFGR1_CHINSEL_MASK, + DFSDM_CHCFGR1_CHINSEL(ch->alt_si)); +} + +static int stm32_dfsdm_start_filter(struct stm32_dfsdm *dfsdm, + unsigned int fl_id) +{ + int ret; + + /* Enable filter */ + ret = regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id), + DFSDM_CR1_DFEN_MASK, DFSDM_CR1_DFEN(1)); + if (ret < 0) + return ret; + + /* Start conversion */ + return regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id), + DFSDM_CR1_RSWSTART_MASK, + DFSDM_CR1_RSWSTART(1)); +} + +void stm32_dfsdm_stop_filter(struct stm32_dfsdm *dfsdm, unsigned int fl_id) +{ + /* Disable conversion */ + regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id), + DFSDM_CR1_DFEN_MASK, DFSDM_CR1_DFEN(0)); +} + +static int stm32_dfsdm_filter_configure(struct stm32_dfsdm *dfsdm, + unsigned int fl_id, unsigned int ch_id) +{ + struct regmap *regmap = dfsdm->regmap; + struct stm32_dfsdm_filter *fl = &dfsdm->fl_list[fl_id]; + int ret; + + /* Average integrator oversampling */ + ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_IOSR_MASK, + DFSDM_FCR_IOSR(fl->iosr - 1)); + if (ret) + return ret; + + /* Filter order and Oversampling */ + ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_FOSR_MASK, + DFSDM_FCR_FOSR(fl->fosr - 1)); + if (ret) + return ret; + + ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_FORD_MASK, + DFSDM_FCR_FORD(fl->ford)); + if (ret) + return ret; + + /* No scan mode supported for the moment */ + ret = regmap_update_bits(regmap, DFSDM_CR1(fl_id), DFSDM_CR1_RCH_MASK, + DFSDM_CR1_RCH(ch_id)); + if (ret) + return ret; + + return regmap_update_bits(regmap, DFSDM_CR1(fl_id), + DFSDM_CR1_RSYNC_MASK, + DFSDM_CR1_RSYNC(fl->sync_mode)); +} + +int stm32_dfsdm_channel_parse_of(struct stm32_dfsdm *dfsdm, + struct iio_dev *indio_dev, + struct iio_chan_spec *ch) +{ + struct stm32_dfsdm_channel *df_ch; + const char *of_str; + int chan_idx = ch->scan_index; + int ret, val; + + ret = of_property_read_u32_index(indio_dev->dev.of_node, + "st,adc-channels", chan_idx, + &ch->channel); + if (ret < 0) { + dev_err(&indio_dev->dev, + " Error parsing 'st,adc-channels' for idx %d\n", + chan_idx); + return ret; + } + if (ch->channel >= dfsdm->num_chs) { + dev_err(&indio_dev->dev, + " Error bad channel number %d (max = %d)\n", + ch->channel, dfsdm->num_chs); + return -EINVAL; + } + + ret = of_property_read_string_index(indio_dev->dev.of_node, + "st,adc-channel-names", chan_idx, + &ch->datasheet_name); + if (ret < 0) { + dev_err(&indio_dev->dev, + " Error parsing 'st,adc-channel-names' for idx %d\n", + chan_idx); + return ret; + } + + df_ch = &dfsdm->ch_list[ch->channel]; + df_ch->id = ch->channel; + + ret = of_property_read_string_index(indio_dev->dev.of_node, + "st,adc-channel-types", chan_idx, + &of_str); + if (!ret) { + val = stm32_dfsdm_str2val(of_str, stm32_dfsdm_chan_type); + if (val < 0) + return val; + } else { + val = 0; + } + df_ch->type = val; + + ret = of_property_read_string_index(indio_dev->dev.of_node, + "st,adc-channel-clk-src", chan_idx, + &of_str); + if (!ret) { + val = stm32_dfsdm_str2val(of_str, stm32_dfsdm_chan_src); + if (val < 0) + return val; + } else { + val = 0; + } + df_ch->src = val; + + ret = of_property_read_u32_index(indio_dev->dev.of_node, + "st,adc-alt-channel", chan_idx, + &df_ch->alt_si); + if (ret < 0) + df_ch->alt_si = 0; + + return 0; +} + +static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc, bool dma) +{ + struct regmap *regmap = adc->dfsdm->regmap; + int ret; + + ret = stm32_dfsdm_start_channel(adc->dfsdm, adc->ch_id); + if (ret < 0) + return ret; + + ret = stm32_dfsdm_filter_configure(adc->dfsdm, adc->fl_id, + adc->ch_id); + if (ret < 0) + goto stop_channels; + + ret = stm32_dfsdm_start_filter(adc->dfsdm, adc->fl_id); + if (ret < 0) + goto stop_channels; + + return 0; + +stop_channels: + regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id), + DFSDM_CR1_RDMAEN_MASK, 0); + + regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id), + DFSDM_CR1_RCONT_MASK, 0); + stm32_dfsdm_stop_channel(adc->dfsdm, adc->fl_id); + + return ret; +} + +static void stm32_dfsdm_stop_conv(struct stm32_dfsdm_adc *adc) +{ + struct regmap *regmap = adc->dfsdm->regmap; + + stm32_dfsdm_stop_filter(adc->dfsdm, adc->fl_id); + + /* Clean conversion options */ + regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id), + DFSDM_CR1_RDMAEN_MASK, 0); + + regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id), + DFSDM_CR1_RCONT_MASK, 0); + + stm32_dfsdm_stop_channel(adc->dfsdm, adc->ch_id); +} + +static int stm32_dfsdm_single_conv(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, int *res) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + long timeout; + int ret; + + reinit_completion(&adc->completion); + + adc->buffer = res; + + ret = stm32_dfsdm_start_dfsdm(adc->dfsdm); + if (ret < 0) + return ret; + + ret = regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id), + DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(1)); + if (ret < 0) + goto stop_dfsdm; + + ret = stm32_dfsdm_start_conv(adc, false); + if (ret < 0) { + regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id), + DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(0)); + goto stop_dfsdm; + } + + timeout = wait_for_completion_interruptible_timeout(&adc->completion, + DFSDM_TIMEOUT); + + /* Mask IRQ for regular conversion achievement*/ + regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id), + DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(0)); + + if (timeout == 0) + ret = -ETIMEDOUT; + else if (timeout < 0) + ret = timeout; + else + ret = IIO_VAL_INT; + + stm32_dfsdm_stop_conv(adc); + +stop_dfsdm: + stm32_dfsdm_stop_dfsdm(adc->dfsdm); + + return ret; +} + +static int stm32_dfsdm_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id]; + int ret = -EINVAL; + + if (mask == IIO_CHAN_INFO_OVERSAMPLING_RATIO) { + ret = stm32_dfsdm_set_osrs(fl, 0, val); + if (!ret) + adc->oversamp = val; + } + + return ret; +} + +static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val, + int *val2, long mask) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = iio_hw_consumer_enable(adc->hwc); + if (ret < 0) { + dev_err(&indio_dev->dev, + "%s: IIO enable failed (channel %d)\n", + __func__, chan->channel); + return ret; + } + ret = stm32_dfsdm_single_conv(indio_dev, chan, val); + iio_hw_consumer_disable(adc->hwc); + if (ret < 0) { + dev_err(&indio_dev->dev, + "%s: Conversion failed (channel %d)\n", + __func__, chan->channel); + return ret; + } + return IIO_VAL_INT; + + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + *val = adc->oversamp; + + return IIO_VAL_INT; + } + + return -EINVAL; +} + +static const struct iio_info stm32_dfsdm_info_adc = { + .read_raw = stm32_dfsdm_read_raw, + .write_raw = stm32_dfsdm_write_raw, +}; + +static irqreturn_t stm32_dfsdm_irq(int irq, void *arg) +{ + struct stm32_dfsdm_adc *adc = arg; + struct iio_dev *indio_dev = iio_priv_to_dev(adc); + struct regmap *regmap = adc->dfsdm->regmap; + unsigned int status, int_en; + + regmap_read(regmap, DFSDM_ISR(adc->fl_id), &status); + regmap_read(regmap, DFSDM_CR2(adc->fl_id), &int_en); + + if (status & DFSDM_ISR_REOCF_MASK) { + /* Read the data register clean the IRQ status */ + regmap_read(regmap, DFSDM_RDATAR(adc->fl_id), adc->buffer); + complete(&adc->completion); + } + + if (status & DFSDM_ISR_ROVRF_MASK) { + if (int_en & DFSDM_CR2_ROVRIE_MASK) + dev_warn(&indio_dev->dev, "Overrun detected\n"); + regmap_update_bits(regmap, DFSDM_ICR(adc->fl_id), + DFSDM_ICR_CLRROVRF_MASK, + DFSDM_ICR_CLRROVRF_MASK); + } + + return IRQ_HANDLED; +} + +static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev, + struct iio_chan_spec *ch) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + int ret; + + ret = stm32_dfsdm_channel_parse_of(adc->dfsdm, indio_dev, ch); + if (ret < 0) + return ret; + + ch->type = IIO_VOLTAGE; + ch->indexed = 1; + + /* + * IIO_CHAN_INFO_RAW: used to compute regular conversion + * IIO_CHAN_INFO_OVERSAMPLING_RATIO: used to set oversampling + */ + 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'; + ch->scan_type.realbits = 24; + ch->scan_type.storagebits = 32; + adc->ch_id = ch->channel; + + return stm32_dfsdm_chan_configure(adc->dfsdm, + &adc->dfsdm->ch_list[ch->channel]); +} + +static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev) +{ + struct iio_chan_spec *ch; + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + int num_ch; + int ret, chan_idx; + + adc->oversamp = DFSDM_DEFAULT_OVERSAMPLING; + ret = stm32_dfsdm_set_osrs(&adc->dfsdm->fl_list[adc->fl_id], 0, + adc->oversamp); + if (ret < 0) + return ret; + + num_ch = of_property_count_u32_elems(indio_dev->dev.of_node, + "st,adc-channels"); + if (num_ch < 0 || num_ch > adc->dfsdm->num_chs) { + dev_err(&indio_dev->dev, "Bad st,adc-channels\n"); + return num_ch < 0 ? num_ch : -EINVAL; + } + + /* Bind to SD modulator IIO device */ + adc->hwc = devm_iio_hw_consumer_alloc(&indio_dev->dev); + if (IS_ERR(adc->hwc)) + return -EPROBE_DEFER; + + ch = devm_kcalloc(&indio_dev->dev, num_ch, sizeof(*ch), + GFP_KERNEL); + if (!ch) + return -ENOMEM; + + for (chan_idx = 0; chan_idx < num_ch; chan_idx++) { + ch->scan_index = chan_idx; + ret = stm32_dfsdm_adc_chan_init_one(indio_dev, ch); + if (ret < 0) { + dev_err(&indio_dev->dev, "Channels init failed\n"); + return ret; + } + } + + indio_dev->num_channels = num_ch; + indio_dev->channels = ch; + + init_completion(&adc->completion); + + return 0; +} + +static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_adc_data = { + .type = DFSDM_IIO, + .init = stm32_dfsdm_adc_init, +}; + +static const struct of_device_id stm32_dfsdm_adc_match[] = { + { .compatible = "st,stm32-dfsdm-adc", + .data = &stm32h7_dfsdm_adc_data, + }, + {} +}; + +static int stm32_dfsdm_adc_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct stm32_dfsdm_adc *adc; + struct device_node *np = dev->of_node; + const struct stm32_dfsdm_dev_data *dev_data; + struct iio_dev *iio; + const struct of_device_id *of_id; + char *name; + int ret, irq, val; + + of_id = of_match_node(stm32_dfsdm_adc_match, np); + if (!of_id->data) { + dev_err(&pdev->dev, "Data associated to device is missing\n"); + return -EINVAL; + } + + dev_data = (const struct stm32_dfsdm_dev_data *)of_id->data; + + iio = devm_iio_device_alloc(dev, sizeof(*adc)); + if (IS_ERR(iio)) { + dev_err(dev, "%s: Failed to allocate IIO\n", __func__); + return PTR_ERR(iio); + } + + adc = iio_priv(iio); + if (IS_ERR(adc)) { + dev_err(dev, "%s: Failed to allocate ADC\n", __func__); + return PTR_ERR(adc); + } + adc->dfsdm = dev_get_drvdata(dev->parent); + + iio->dev.parent = dev; + iio->dev.of_node = np; + iio->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE; + + platform_set_drvdata(pdev, adc); + + ret = of_property_read_u32(dev->of_node, "reg", &adc->fl_id); + if (ret != 0) { + dev_err(dev, "Missing reg property\n"); + return -EINVAL; + } + + 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); + 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, adc); + 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; + } + + adc->dfsdm->fl_list[adc->fl_id].ford = val; + + ret = of_property_read_u32(dev->of_node, "st,filter0-sync", &val); + if (!ret) + adc->dfsdm->fl_list[adc->fl_id].sync_mode = val; + + adc->dev_data = dev_data; + ret = dev_data->init(iio); + if (ret < 0) + return ret; + + return iio_device_register(iio); +} + +static int stm32_dfsdm_adc_remove(struct platform_device *pdev) +{ + struct stm32_dfsdm_adc *adc = platform_get_drvdata(pdev); + struct iio_dev *indio_dev = iio_priv_to_dev(adc); + + iio_device_unregister(indio_dev); + + return 0; +} + +static struct platform_driver stm32_dfsdm_adc_driver = { + .driver = { + .name = "stm32-dfsdm-adc", + .of_match_table = stm32_dfsdm_adc_match, + }, + .probe = stm32_dfsdm_adc_probe, + .remove = stm32_dfsdm_adc_remove, + +}; +module_platform_driver(stm32_dfsdm_adc_driver); + +MODULE_DESCRIPTION("STM32 sigma delta ADC"); +MODULE_AUTHOR("Arnaud Pouliquen arnaud.pouliquen@st.com"); +MODULE_LICENSE("GPL v2");

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 --- .../ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 | 16 + drivers/iio/adc/stm32-dfsdm-adc.c | 507 ++++++++++++++++++++- include/linux/iio/adc/stm32-dfsdm-adc.h | 28 ++ 3 files changed, 543 insertions(+), 8 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 create mode 100644 include/linux/iio/adc/stm32-dfsdm-adc.h

diff --git a/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 b/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 new file mode 100644 index 0000000..da98223 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 @@ -0,0 +1,16 @@ +What: /sys/bus/iio/devices/iio:deviceX/in_voltage_spi_clk_freq +KernelVersion: 4.14 +Contact: arnaud.pouliquen@st.com +Description: + For audio purpose only. + Used by audio driver to set/get the spi input frequency. + This is mandatory if DFSDM is slave on SPI bus, to + provide information on the SPI clock frequency during runtime + Notice that the SPI frequency should be a multiple of sample + frequency to ensure the precision. + if DFSDM input is SPI master + Reading SPI clkout frequency, + error on writing + If DFSDM input is SPI Slave: + Reading returns value previously set. + Writing value before starting conversions. \ No newline at end of file diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c index f9419ab..80b0ca7 100644 --- a/drivers/iio/adc/stm32-dfsdm-adc.c +++ b/drivers/iio/adc/stm32-dfsdm-adc.c @@ -19,19 +19,25 @@ * 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/of_device.h> #include <linux/platform_device.h> #include <linux/regmap.h> #include <linux/slab.h>

#include "stm32-dfsdm.h"

+#define DFSDM_DMA_BUFFER_SIZE (4 * PAGE_SIZE) + /* Conversion timeout */ #define DFSDM_TIMEOUT_US 100000 #define DFSDM_TIMEOUT (msecs_to_jiffies(DFSDM_TIMEOUT_US / 1000)) @@ -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 +382,63 @@ int stm32_dfsdm_channel_parse_of(struct stm32_dfsdm *dfsdm, return 0; }

+static ssize_t dfsdm_adc_audio_get_spiclk(struct iio_dev *indio_dev, + uintptr_t priv, + const struct iio_chan_spec *chan, + char *buf) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + + return snprintf(buf, PAGE_SIZE, "%d\n", adc->spi_freq); +} + +static ssize_t dfsdm_adc_audio_set_spiclk(struct iio_dev *indio_dev, + uintptr_t priv, + const struct iio_chan_spec *chan, + const char *buf, size_t len) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id]; + struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[adc->ch_id]; + unsigned int sample_freq = adc->sample_freq; + unsigned int spi_freq; + int ret; + + dev_err(&indio_dev->dev, "enter %s\n", __func__); + /* If DFSDM is master on SPI, SPI freq can not be updated */ + if (ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL) + return -EPERM; + + ret = kstrtoint(buf, 0, &spi_freq); + if (ret) + return ret; + + if (!spi_freq) + return -EINVAL; + + if (sample_freq) { + if (spi_freq % sample_freq) + dev_warn(&indio_dev->dev, + "Sampling rate not accurate (%d)\n", + spi_freq / (spi_freq / sample_freq)); + + ret = stm32_dfsdm_set_osrs(fl, 0, (spi_freq / sample_freq)); + if (ret < 0) { + dev_err(&indio_dev->dev, + "No filter parameters that match!\n"); + return ret; + } + } + adc->spi_freq = spi_freq; + + return len; +} + static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc, bool dma) { struct regmap *regmap = adc->dfsdm->regmap; int ret; + unsigned int dma_en = 0, cont_en = 0;

ret = stm32_dfsdm_start_channel(adc->dfsdm, adc->ch_id); if (ret < 0) @@ -378,6 +449,24 @@ 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 +500,231 @@ static void stm32_dfsdm_stop_conv(struct stm32_dfsdm_adc *adc) stm32_dfsdm_stop_channel(adc->dfsdm, adc->ch_id); }

+static int stm32_dfsdm_set_watermark(struct iio_dev *indio_dev, + unsigned int val) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + unsigned int watermark = DFSDM_DMA_BUFFER_SIZE / 2; + + /* + * DMA cyclic transfers are used, buffer is split into two periods. + * There should be : + * - always one buffer (period) DMA is working on + * - one buffer (period) driver pushed to ASoC side. + */ + watermark = min(watermark, val * (unsigned int)(sizeof(u32))); + adc->buf_sz = watermark * 2; + + return 0; +} + +static unsigned int stm32_dfsdm_adc_dma_residue(struct stm32_dfsdm_adc *adc) +{ + struct dma_tx_state state; + enum dma_status status; + + status = dmaengine_tx_status(adc->dma_chan, + adc->dma_chan->cookie, + &state); + if (status == DMA_IN_PROGRESS) { + /* Residue is size in bytes from end of buffer */ + unsigned int i = adc->buf_sz - state.residue; + unsigned int size; + + /* Return available bytes */ + if (i >= adc->bufi) + size = i - adc->bufi; + else + size = adc->buf_sz + i - adc->bufi; + + return size; + } + + return 0; +} + +static void stm32_dfsdm_audio_dma_buffer_done(void *data) +{ + struct iio_dev *indio_dev = data; + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + int available = stm32_dfsdm_adc_dma_residue(adc); + size_t old_pos; + + /* + * FIXME: In Kernel interface does not support cyclic DMA buffer,and + * offers only an interface to push data samples per samples. + * For this reason IIO buffer interface is not used and interface is + * bypassed using a private callback registered by ASoC. + * This should be a temporary solution waiting a cyclic DMA engine + * support in IIO. + */ + + dev_dbg(&indio_dev->dev, "%s: pos = %d, available = %d\n", __func__, + adc->bufi, available); + old_pos = adc->bufi; + + while (available >= indio_dev->scan_bytes) { + u32 *buffer = (u32 *)&adc->rx_buf[adc->bufi]; + + /* Mask 8 LSB that contains the channel ID */ + *buffer = (*buffer & 0xFFFFFF00) << 8; + available -= indio_dev->scan_bytes; + adc->bufi += indio_dev->scan_bytes; + if (adc->bufi >= adc->buf_sz) { + if (adc->cb) + adc->cb(&adc->rx_buf[old_pos], + adc->buf_sz - old_pos, adc->cb_priv); + adc->bufi = 0; + old_pos = 0; + } + } + if (adc->cb) + adc->cb(&adc->rx_buf[old_pos], adc->bufi - old_pos, + adc->cb_priv); +} + +static int stm32_dfsdm_adc_dma_start(struct iio_dev *indio_dev) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + struct dma_async_tx_descriptor *desc; + dma_cookie_t cookie; + int ret; + + if (!adc->dma_chan) + return -EINVAL; + + dev_dbg(&indio_dev->dev, "%s size=%d watermark=%d\n", __func__, + adc->buf_sz, adc->buf_sz / 2); + + /* Prepare a DMA cyclic transaction */ + desc = dmaengine_prep_dma_cyclic(adc->dma_chan, + adc->dma_buf, + adc->buf_sz, adc->buf_sz / 2, + DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT); + if (!desc) + return -EBUSY; + + desc->callback = stm32_dfsdm_audio_dma_buffer_done; + desc->callback_param = indio_dev; + + cookie = dmaengine_submit(desc); + ret = dma_submit_error(cookie); + if (ret) { + dmaengine_terminate_all(adc->dma_chan); + return ret; + } + + /* Issue pending DMA requests */ + dma_async_issue_pending(adc->dma_chan); + + return 0; +} + +static int stm32_dfsdm_postenable(struct iio_dev *indio_dev) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + int ret; + + /* Reset adc buffer index */ + adc->bufi = 0; + + ret = stm32_dfsdm_start_dfsdm(adc->dfsdm); + if (ret < 0) + return ret; + + ret = stm32_dfsdm_start_conv(adc, true); + if (ret) { + dev_err(&indio_dev->dev, "Can't start conversion\n"); + goto stop_dfsdm; + } + + if (adc->dma_chan) { + ret = stm32_dfsdm_adc_dma_start(indio_dev); + if (ret) { + dev_err(&indio_dev->dev, "Can't start DMA\n"); + goto err_stop_conv; + } + } + + return 0; + +err_stop_conv: + stm32_dfsdm_stop_conv(adc); +stop_dfsdm: + stm32_dfsdm_stop_dfsdm(adc->dfsdm); + + return ret; +} + +static int stm32_dfsdm_predisable(struct iio_dev *indio_dev) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + + if (adc->dma_chan) + dmaengine_terminate_all(adc->dma_chan); + + stm32_dfsdm_stop_conv(adc); + + stm32_dfsdm_stop_dfsdm(adc->dfsdm); + + return 0; +} + +static const struct iio_buffer_setup_ops stm32_dfsdm_buffer_setup_ops = { + .postenable = &stm32_dfsdm_postenable, + .predisable = &stm32_dfsdm_predisable, +}; + +/** + * stm32_dfsdm_get_buff_cb() - register a callback that will be called when + * DMA transfer period is achieved. + * + * @iio_dev: Handle to IIO device. + * @cb: Pointer to callback function: + * - data: pointer to data buffer + * - size: size in byte of the data buffer + * - private: pointer to consumer private structure. + * @private: Pointer to consumer private structure. + */ +int stm32_dfsdm_get_buff_cb(struct iio_dev *iio_dev, + int (*cb)(const void *data, size_t size, + void *private), + void *private) +{ + struct stm32_dfsdm_adc *adc; + + if (!iio_dev) + return -EINVAL; + adc = iio_priv(iio_dev); + + adc->cb = cb; + adc->cb_priv = private; + + return 0; +} +EXPORT_SYMBOL_GPL(stm32_dfsdm_get_buff_cb); + +/** + * stm32_dfsdm_release_buff_cb - unregister buffer callback + * + * @iio_dev: Handle to IIO device. + */ +int stm32_dfsdm_release_buff_cb(struct iio_dev *iio_dev) +{ + struct stm32_dfsdm_adc *adc; + + if (!iio_dev) + return -EINVAL; + adc = iio_priv(iio_dev); + + adc->cb = NULL; + adc->cb_priv = NULL; + + return 0; +} +EXPORT_SYMBOL_GPL(stm32_dfsdm_release_buff_cb); + static int stm32_dfsdm_single_conv(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, int *res) { @@ -466,15 +780,41 @@ static int stm32_dfsdm_write_raw(struct iio_dev *indio_dev, { struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id]; + struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[adc->ch_id]; + unsigned int spi_freq = adc->spi_freq; int ret = -EINVAL;

- if (mask == IIO_CHAN_INFO_OVERSAMPLING_RATIO) { + switch (mask) { + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: ret = stm32_dfsdm_set_osrs(fl, 0, val); if (!ret) adc->oversamp = val; + + return ret; + + case IIO_CHAN_INFO_SAMP_FREQ: + if (!val) + return -EINVAL; + if (ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL) + spi_freq = adc->dfsdm->spi_master_freq; + + if (spi_freq % val) + dev_warn(&indio_dev->dev, + "Sampling rate not accurate (%d)\n", + spi_freq / (spi_freq / val)); + + ret = stm32_dfsdm_set_osrs(fl, 0, (spi_freq / val)); + if (ret < 0) { + dev_err(&indio_dev->dev, + "Not able to find parameter that match!\n"); + return ret; + } + adc->sample_freq = val; + + return 0; }

- return ret; + return -EINVAL; }

static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev, @@ -507,11 +847,22 @@ static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev, *val = adc->oversamp;

return IIO_VAL_INT; + + case IIO_CHAN_INFO_SAMP_FREQ: + *val = adc->sample_freq; + + return IIO_VAL_INT; }

return -EINVAL; }

+static const struct iio_info stm32_dfsdm_info_audio = { + .hwfifo_set_watermark = stm32_dfsdm_set_watermark, + .read_raw = stm32_dfsdm_read_raw, + .write_raw = stm32_dfsdm_write_raw, +}; + static const struct iio_info stm32_dfsdm_info_adc = { .read_raw = stm32_dfsdm_read_raw, .write_raw = stm32_dfsdm_write_raw, @@ -544,6 +895,60 @@ static irqreturn_t stm32_dfsdm_irq(int irq, void *arg) return IRQ_HANDLED; }

+/* + * Define external info for SPI Frequency and audio sampling rate that can be + * configured by ASoC driver through consumer.h API + */ +static const struct iio_chan_spec_ext_info dfsdm_adc_audio_ext_info[] = { + /* spi_clk_freq : clock freq on SPI/manchester bus used by channel */ + { + .name = "spi_clk_freq", + .shared = IIO_SHARED_BY_TYPE, + .read = dfsdm_adc_audio_get_spiclk, + .write = dfsdm_adc_audio_set_spiclk, + }, + {}, +}; + +static 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 +969,12 @@ 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 +983,64 @@ static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev, &adc->dfsdm->ch_list[ch->channel]); }

+static int stm32_dfsdm_audio_init(struct iio_dev *indio_dev) +{ + struct iio_chan_spec *ch; + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + struct stm32_dfsdm_channel *d_ch; + int ret; + + 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; + } + ch->info_mask_separate = BIT(IIO_CHAN_INFO_SAMP_FREQ); + + d_ch = &adc->dfsdm->ch_list[adc->ch_id]; + if (d_ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL) + adc->spi_freq = adc->dfsdm->spi_master_freq; + + indio_dev->num_channels = 1; + indio_dev->channels = ch; + + return 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 +1093,18 @@ 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 +1155,13 @@ 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;

/* @@ -712,7 +1193,10 @@ static int stm32_dfsdm_adc_probe(struct platform_device *pdev) if (ret < 0) return ret;

- return iio_device_register(iio); + iio_device_register(iio); + if (dev_data->type == DFSDM_AUDIO) + return devm_of_platform_populate(&pdev->dev); + return 0; }

static int stm32_dfsdm_adc_remove(struct platform_device *pdev) @@ -721,7 +1205,14 @@ 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..cad7963 --- /dev/null +++ b/include/linux/iio/adc/stm32-dfsdm-adc.h @@ -0,0 +1,28 @@ +/* + * 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

Add bindings that describes audio settings to support Digital Filter for pulse density modulation(PDM) microphone.

Signed-off-by: Arnaud Pouliquen arnaud.pouliquen@st.com --- .../devicetree/bindings/sound/st,stm32-adfsdm.txt | 62 ++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100644 Documentation/devicetree/bindings/sound/st,stm32-adfsdm.txt

diff --git a/Documentation/devicetree/bindings/sound/st,stm32-adfsdm.txt b/Documentation/devicetree/bindings/sound/st,stm32-adfsdm.txt new file mode 100644 index 0000000..2782cda --- /dev/null +++ b/Documentation/devicetree/bindings/sound/st,stm32-adfsdm.txt @@ -0,0 +1,62 @@ +STMicroelectronics Audio Digital Filter Sigma Delta modulators(DFSDM) + +The DFSDM allows PDM microphones capture through SPI interface. The Audio +interface is seems as a sub block of the DFSDM device. +For details on DFSDM bindings refer to ../iio/adc/st,stm32-dfsdm-adc.txt + +Required properties: + - compatible: "st,stm32h7-dfsdm-dai". + + - #sound-dai-cells : Must be equal to 0 + + - io-channels : phandle to iio dfsdm instance node. + +Example of a sound card using audio DFSDM node. + + sound_card { + compatible = "audio-graph-card"; + + dais = <&cpu_port>; + }; + + dfsdm: dfsdm@40017000 { + compatible = "st,stm32h7-dfsdm"; + reg = <0x40017000 0x400>; + clocks = <&rcc DFSDM1_CK>; + clock-names = "dfsdm"; + #address-cells = <1>; + #size-cells = <0>; + + dfsdm_adc0: dfsdm-adc@0 { + compatible = "st,stm32-dfsdm-dmic"; + reg = <0>; + interrupts = <110>; + dmas = <&dmamux1 101 0x400 0x00>; + dma-names = "rx"; + st,adc-channels = <1>; + st,adc-channel-names = "dmic0"; + st,adc-channel-types = "SPI_R"; + st,adc-channel-clk-src = "CLKOUT"; + st,filter-order = <5>; + + dfsdm_dai0: dfsdm-dai { + compatible = "st,stm32h7-dfsdm-dai"; + #sound-dai-cells = <0>; + io-channels = <&dfsdm_adc0 0>; + cpu_port: port { + dfsdm_endpoint: endpoint { + remote-endpoint = <&dmic0_endpoint>; + }; + }; + }; + }; + + dmic0: dmic@0 { + compatible = "dmic-codec"; + #sound-dai-cells = <0>; + port { + dmic0_endpoint: endpoint { + remote-endpoint = <&dfsdm_endpoint>; + }; + }; + };

Add driver to handle DAI interface for PDM microphones connected to Digital Filter for Sigma Delta Modulators IP.

Signed-off-by: Arnaud Pouliquen arnaud.pouliquen@st.com --- V5 to V6 update: fix build warning

sound/soc/stm/Kconfig | 11 ++ sound/soc/stm/Makefile | 3 + sound/soc/stm/stm32_adfsdm.c | 386 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 400 insertions(+) create mode 100644 sound/soc/stm/stm32_adfsdm.c

diff --git a/sound/soc/stm/Kconfig b/sound/soc/stm/Kconfig index 3398e6c..a78f770 100644 --- a/sound/soc/stm/Kconfig +++ b/sound/soc/stm/Kconfig @@ -28,4 +28,15 @@ config SND_SOC_STM32_SPDIFRX help Say Y if you want to enable S/PDIF capture for STM32

+config SND_SOC_STM32_DFSDM + tristate "SoC Audio support for STM32 DFSDM" + depends on (ARCH_STM32 && OF && STM32_DFSDM_ADC) || COMPILE_TEST + depends on SND_SOC + select SND_SOC_GENERIC_DMAENGINE_PCM + select SND_SOC_DMIC + select IIO_BUFFER_CB + help + Select this option to enable the STM32 Digital Filter + for Sigma Delta Modulators (DFSDM) driver used + in various STM32 series for digital microphone capture. endmenu diff --git a/sound/soc/stm/Makefile b/sound/soc/stm/Makefile index 4ed22e6..53e90e6 100644 --- a/sound/soc/stm/Makefile +++ b/sound/soc/stm/Makefile @@ -12,3 +12,6 @@ obj-$(CONFIG_SND_SOC_STM32_I2S) += snd-soc-stm32-i2s.o # SPDIFRX snd-soc-stm32-spdifrx-objs := stm32_spdifrx.o obj-$(CONFIG_SND_SOC_STM32_SPDIFRX) += snd-soc-stm32-spdifrx.o + +#DFSDM +obj-$(CONFIG_SND_SOC_STM32_DFSDM) += stm32_adfsdm.o diff --git a/sound/soc/stm/stm32_adfsdm.c b/sound/soc/stm/stm32_adfsdm.c new file mode 100644 index 0000000..890ec24 --- /dev/null +++ b/sound/soc/stm/stm32_adfsdm.c @@ -0,0 +1,386 @@ +/* + * This file is part of STM32 DFSDM ASoC DAI driver + * + * Copyright (C) 2017, STMicroelectronics - All Rights Reserved + * Authors: Arnaud Pouliquen arnaud.pouliquen@st.com + * Olivier Moysan olivier.moysan@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. + * + * 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/clk.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +#include <linux/iio/iio.h> +#include <linux/iio/consumer.h> +#include <linux/iio/adc/stm32-dfsdm-adc.h> + +#include <sound/pcm.h> +#include <sound/soc.h> + +#define STM32_ADFSDM_DRV_NAME "stm32-adfsdm" + +#define DFSDM_MAX_PERIOD_SIZE (PAGE_SIZE / 2) +#define DFSDM_MAX_PERIODS 6 + +struct stm32_adfsdm_priv { + struct snd_soc_dai_driver dai_drv; + struct snd_pcm_substream *substream; + struct device *dev; + + /* IIO */ + struct iio_channel *iio_ch; + struct iio_cb_buffer *iio_cb; + bool iio_active; + + /* PCM buffer */ + unsigned char *pcm_buff; + unsigned int pos; + bool allocated; +}; + +struct stm32_adfsdm_data { + unsigned int rate; /* SNDRV_PCM_RATE value */ + unsigned int freq; /* frequency in Hz */ +}; + +static const struct snd_pcm_hardware stm32_adfsdm_pcm_hw = { + .info = SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER | + SNDRV_PCM_INFO_PAUSE, + .formats = SNDRV_PCM_FMTBIT_S32_LE, + + .rate_min = 8000, + .rate_max = 32000, + + .channels_min = 1, + .channels_max = 1, + + .periods_min = 2, + .periods_max = DFSDM_MAX_PERIODS, + + .period_bytes_max = DFSDM_MAX_PERIOD_SIZE, + .buffer_bytes_max = DFSDM_MAX_PERIODS * DFSDM_MAX_PERIOD_SIZE +}; + +static void stm32_adfsdm_shutdown(struct snd_pcm_substream *substream, + struct snd_soc_dai *dai) +{ + struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai); + + if (priv->iio_active) { + iio_channel_stop_all_cb(priv->iio_cb); + priv->iio_active = false; + } +} + +static int stm32_adfsdm_dai_prepare(struct snd_pcm_substream *substream, + struct snd_soc_dai *dai) +{ + struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai); + int ret; + + ret = iio_write_channel_attribute(priv->iio_ch, + substream->runtime->rate, 0, + IIO_CHAN_INFO_SAMP_FREQ); + if (ret < 0) { + dev_err(dai->dev, "%s: Failed to set %d sampling rate\n", + __func__, substream->runtime->rate); + return ret; + } + + if (!priv->iio_active) { + ret = iio_channel_start_all_cb(priv->iio_cb); + if (!ret) + priv->iio_active = true; + else + dev_err(dai->dev, "%s: IIO channel start failed (%d)\n", + __func__, ret); + } + + return ret; +} + +static int stm32_adfsdm_set_sysclk(struct snd_soc_dai *dai, int clk_id, + unsigned int freq, int dir) +{ + struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai); + ssize_t size; + + dev_dbg(dai->dev, "%s: Enter for freq %d\n", __func__, freq); + + /* Set IIO frequency if CODEC is master as clock comes from SPI_IN*/ + if (dir == SND_SOC_CLOCK_IN) { + char str_freq[10]; + + snprintf(str_freq, sizeof(str_freq), "%d\n", freq); + size = iio_write_channel_ext_info(priv->iio_ch, "spi_clk_freq", + str_freq, sizeof(str_freq)); + if (size != sizeof(str_freq)) { + dev_err(dai->dev, "%s: Failed to set SPI clock\n", + __func__); + return -EINVAL; + } + } + return 0; +} + +static const struct snd_soc_dai_ops stm32_adfsdm_dai_ops = { + .shutdown = stm32_adfsdm_shutdown, + .prepare = stm32_adfsdm_dai_prepare, + .set_sysclk = stm32_adfsdm_set_sysclk, +}; + +static const struct snd_soc_dai_driver stm32_adfsdm_dai = { + .capture = { + .channels_min = 1, + .channels_max = 1, + .formats = SNDRV_PCM_FMTBIT_S32_LE, + .rates = (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_16000 | + SNDRV_PCM_RATE_32000), + }, + .ops = &stm32_adfsdm_dai_ops, +}; + +static const struct snd_soc_component_driver stm32_adfsdm_dai_component = { + .name = "stm32_dfsdm_audio", +}; + +static int stm32_afsdm_pcm_cb(const void *data, size_t size, void *private) +{ + struct stm32_adfsdm_priv *priv = private; + struct snd_soc_pcm_runtime *rtd = priv->substream->private_data; + u8 *pcm_buff = priv->pcm_buff; + u8 *src_buff = (u8 *)data; + unsigned int buff_size = snd_pcm_lib_buffer_bytes(priv->substream); + unsigned int period_size = snd_pcm_lib_period_bytes(priv->substream); + unsigned int old_pos = priv->pos; + unsigned int cur_size = size; + + dev_dbg(rtd->dev, "%s: buff_add :%p, pos = %d, size = %lu\n", + __func__, &pcm_buff[priv->pos], priv->pos, size); + + if ((priv->pos + size) > buff_size) { + memcpy(&pcm_buff[priv->pos], src_buff, buff_size - priv->pos); + cur_size -= buff_size - priv->pos; + priv->pos = 0; + } + + memcpy(&pcm_buff[priv->pos], &src_buff[size - cur_size], cur_size); + priv->pos = (priv->pos + cur_size) % buff_size; + + if (cur_size != size || (old_pos && (old_pos % period_size < size))) + snd_pcm_period_elapsed(priv->substream); + + return 0; +} + +static int stm32_adfsdm_trigger(struct snd_pcm_substream *substream, int cmd) +{ + struct snd_soc_pcm_runtime *rtd = substream->private_data; + struct stm32_adfsdm_priv *priv = + snd_soc_dai_get_drvdata(rtd->cpu_dai); + + switch (cmd) { + case SNDRV_PCM_TRIGGER_START: + case SNDRV_PCM_TRIGGER_RESUME: + priv->pos = 0; + return stm32_dfsdm_get_buff_cb(priv->iio_ch->indio_dev, + stm32_afsdm_pcm_cb, priv); + case SNDRV_PCM_TRIGGER_SUSPEND: + case SNDRV_PCM_TRIGGER_STOP: + return stm32_dfsdm_release_buff_cb(priv->iio_ch->indio_dev); + default: + return -EINVAL; + } + + return 0; +} + +static int stm32_adfsdm_pcm_open(struct snd_pcm_substream *substream) +{ + struct snd_soc_pcm_runtime *rtd = substream->private_data; + struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(rtd->cpu_dai); + int ret; + + ret = snd_soc_set_runtime_hwparams(substream, &stm32_adfsdm_pcm_hw); + if (!ret) + priv->substream = substream; + + return ret; +} + +static int stm32_adfsdm_pcm_close(struct snd_pcm_substream *substream) +{ + struct snd_soc_pcm_runtime *rtd = substream->private_data; + struct stm32_adfsdm_priv *priv = + snd_soc_dai_get_drvdata(rtd->cpu_dai); + + snd_pcm_lib_free_pages(substream); + priv->substream = NULL; + + return 0; +} + +static snd_pcm_uframes_t stm32_adfsdm_pcm_pointer( + struct snd_pcm_substream *substream) +{ + struct snd_soc_pcm_runtime *rtd = substream->private_data; + struct stm32_adfsdm_priv *priv = + snd_soc_dai_get_drvdata(rtd->cpu_dai); + + return bytes_to_frames(substream->runtime, priv->pos); +} + +static int stm32_adfsdm_pcm_hw_params(struct snd_pcm_substream *substream, + struct snd_pcm_hw_params *params) +{ + struct snd_soc_pcm_runtime *rtd = substream->private_data; + struct stm32_adfsdm_priv *priv = + snd_soc_dai_get_drvdata(rtd->cpu_dai); + int ret; + + ret = snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params)); + if (ret < 0) + return ret; + priv->pcm_buff = substream->runtime->dma_area; + + return iio_channel_cb_set_buffer_watermark(priv->iio_cb, + params_period_size(params)); +} + +static int stm32_adfsdm_pcm_hw_free(struct snd_pcm_substream *substream) +{ + snd_pcm_lib_free_pages(substream); + + return 0; +} + +static struct snd_pcm_ops stm32_adfsdm_pcm_ops = { + .open = stm32_adfsdm_pcm_open, + .close = stm32_adfsdm_pcm_close, + .hw_params = stm32_adfsdm_pcm_hw_params, + .hw_free = stm32_adfsdm_pcm_hw_free, + .trigger = stm32_adfsdm_trigger, + .pointer = stm32_adfsdm_pcm_pointer, +}; + +static int stm32_adfsdm_pcm_new(struct snd_soc_pcm_runtime *rtd) +{ + struct snd_pcm *pcm = rtd->pcm; + struct stm32_adfsdm_priv *priv = + snd_soc_dai_get_drvdata(rtd->cpu_dai); + unsigned int size = DFSDM_MAX_PERIODS * DFSDM_MAX_PERIOD_SIZE; + int ret; + + /* + * FIXME : + * A platform as been registered per DAI. + * In soc_new_pcm function, pcm_new callback is called for each + * component of the sound card. So if n dai links are created this + * function is called n times. + */ + if (priv->allocated) + return 0; + + ret = snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV, + priv->dev, size, size); + if (!ret) + priv->allocated = true; + + return ret; +} + +static void stm32_adfsdm_pcm_free(struct snd_pcm *pcm) +{ + struct snd_pcm_substream *substream; + struct snd_soc_pcm_runtime *rtd; + struct stm32_adfsdm_priv *priv; + + substream = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream; + if (substream) { + rtd = substream->private_data; + priv = snd_soc_dai_get_drvdata(rtd->cpu_dai); + + snd_pcm_lib_preallocate_free_for_all(pcm); + priv->allocated = false; + } +} + +static struct snd_soc_platform_driver stm32_adfsdm_soc_platform = { + .ops = &stm32_adfsdm_pcm_ops, + .pcm_new = stm32_adfsdm_pcm_new, + .pcm_free = stm32_adfsdm_pcm_free, +}; + +static const struct of_device_id stm32_adfsdm_of_match[] = { + {.compatible = "st,stm32h7-dfsdm-dai"}, + {} +}; +MODULE_DEVICE_TABLE(of, stm32_adfsdm_of_match); + +static int stm32_adfsdm_probe(struct platform_device *pdev) +{ + struct stm32_adfsdm_priv *priv; + int ret; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->dev = &pdev->dev; + priv->dai_drv = stm32_adfsdm_dai; + + dev_set_drvdata(&pdev->dev, priv); + + ret = devm_snd_soc_register_component(&pdev->dev, + &stm32_adfsdm_dai_component, + &priv->dai_drv, 1); + if (ret < 0) + return ret; + + /* Associate iio channel */ + priv->iio_ch = devm_iio_channel_get_all(&pdev->dev); + if (IS_ERR(priv->iio_ch)) + return PTR_ERR(priv->iio_ch); + + priv->iio_cb = iio_channel_get_all_cb(&pdev->dev, NULL, NULL); + if (IS_ERR(priv->iio_cb)) + return PTR_ERR(priv->iio_ch); + + ret = devm_snd_soc_register_platform(&pdev->dev, + &stm32_adfsdm_soc_platform); + if (ret < 0) + dev_err(&pdev->dev, "%s: Failed to register PCM platform\n", + __func__); + + return ret; +} + +static struct platform_driver stm32_adfsdm_driver = { + .driver = { + .name = STM32_ADFSDM_DRV_NAME, + .of_match_table = stm32_adfsdm_of_match, + }, + .probe = stm32_adfsdm_probe, +}; + +module_platform_driver(stm32_adfsdm_driver); + +MODULE_DESCRIPTION("stm32 DFSDM DAI driver"); +MODULE_AUTHOR("Arnaud Pouliquen arnaud.pouliquen@st.com"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:" STM32_ADFSDM_DRV_NAME);