| Message ID | 1510222354-15290-8-git-send-email-arnaud.pouliquen@st.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 9 Nov 2017 11:12:29 +0100 Arnaud Pouliquen <arnaud.pouliquen@st.com> wrote: > Add driver for stm32 DFSDM pheripheral. Its converts a sigma delta > stream in n bit samples through a low pass filter and an integrator. > stm32-dfsdm-core driver is the core part supporting the filter > instances dedicated to sigma-delta ADC or audio PDM microphone purpose. > > Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@st.com> Looks good to me.. Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> > --- > V3 -> V4 changes: > - Patch is split into 2 parts, one dedicated to the core part, another dedicated to > the ADC part. > - Filter and channel functions migrated to ADC driver. > > drivers/iio/adc/Kconfig | 12 ++ > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/stm32-dfsdm-core.c | 318 ++++++++++++++++++++++++++++++++++++ > drivers/iio/adc/stm32-dfsdm.h | 319 +++++++++++++++++++++++++++++++++++++ > 4 files changed, 650 insertions(+) > create mode 100644 drivers/iio/adc/stm32-dfsdm-core.c > create mode 100644 drivers/iio/adc/stm32-dfsdm.h > > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index c5db62f..b729ae0 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -665,6 +665,18 @@ config STM32_ADC > This driver can also be built as a module. If so, the module > will be called stm32-adc. > > +config STM32_DFSDM_CORE > + tristate "STMicroelectronics STM32 DFSDM core" > + depends on (ARCH_STM32 && OF) || COMPILE_TEST > + select REGMAP > + select REGMAP_MMIO > + help > + Select this option to enable the driver 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-core. > + > 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 d800325..b52d0a0 100644 > --- a/drivers/iio/adc/Makefile > +++ b/drivers/iio/adc/Makefile > @@ -63,6 +63,7 @@ obj-$(CONFIG_STX104) += stx104.o > obj-$(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_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-core.c b/drivers/iio/adc/stm32-dfsdm-core.c > new file mode 100644 > index 0000000..0be5155 > --- /dev/null > +++ b/drivers/iio/adc/stm32-dfsdm-core.c > @@ -0,0 +1,318 @@ > +/* > + * This file is part the core part STM32 DFSDM driver > + * > + * Copyright (C) 2017, STMicroelectronics - All Rights Reserved > + * Author(s): Arnaud Pouliquen <arnaud.pouliquen@st.com> for STMicroelectronics. > + * > + * 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. > + */ > + > +#include <linux/clk.h> > +#include <linux/iio/iio.h> > +#include <linux/iio/sysfs.h> > +#include <linux/interrupt.h> > +#include <linux/module.h> > +#include <linux/of_device.h> > +#include <linux/regmap.h> > +#include <linux/slab.h> > + > +#include "stm32-dfsdm.h" > + > +struct stm32_dfsdm_dev_data { > + unsigned int num_filters; > + unsigned int num_channels; > + const struct regmap_config *regmap_cfg; > +}; > + > +#define STM32H7_DFSDM_NUM_FILTERS 4 > +#define STM32H7_DFSDM_NUM_CHANNELS 8 > + > +static bool stm32_dfsdm_volatile_reg(struct device *dev, unsigned int reg) > +{ > + if (reg < DFSDM_FILTER_BASE_ADR) > + return false; > + > + /* > + * Mask is done on register to avoid to list registers of all > + * filter instances. > + */ > + switch (reg & DFSDM_FILTER_REG_MASK) { > + case DFSDM_CR1(0) & DFSDM_FILTER_REG_MASK: > + case DFSDM_ISR(0) & DFSDM_FILTER_REG_MASK: > + case DFSDM_JDATAR(0) & DFSDM_FILTER_REG_MASK: > + case DFSDM_RDATAR(0) & DFSDM_FILTER_REG_MASK: > + return true; > + } > + > + return false; > +} > + > +static const struct regmap_config stm32h7_dfsdm_regmap_cfg = { > + .reg_bits = 32, > + .val_bits = 32, > + .reg_stride = sizeof(u32), > + .max_register = 0x2B8, > + .volatile_reg = stm32_dfsdm_volatile_reg, > + .fast_io = true, > +}; > + > +static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_data = { > + .num_filters = STM32H7_DFSDM_NUM_FILTERS, > + .num_channels = STM32H7_DFSDM_NUM_CHANNELS, > + .regmap_cfg = &stm32h7_dfsdm_regmap_cfg, > +}; > + > +struct dfsdm_priv { > + struct platform_device *pdev; /* platform device */ > + > + struct stm32_dfsdm dfsdm; /* common data exported for all instances */ > + > + unsigned int spi_clk_out_div; /* SPI clkout divider value */ > + atomic_t n_active_ch; /* number of current active channels */ > + > + struct clk *clk; /* DFSDM clock */ > + struct clk *aclk; /* audio clock */ > +}; > + > +/** > + * stm32_dfsdm_start_dfsdm - start global dfsdm interface. > + * > + * Enable interface if n_active_ch is not null. > + * @dfsdm: Handle used to retrieve dfsdm context. > + */ > +int stm32_dfsdm_start_dfsdm(struct stm32_dfsdm *dfsdm) > +{ > + struct dfsdm_priv *priv = container_of(dfsdm, struct dfsdm_priv, dfsdm); > + struct device *dev = &priv->pdev->dev; > + unsigned int clk_div = priv->spi_clk_out_div; > + int ret; > + > + if (atomic_inc_return(&priv->n_active_ch) == 1) { > + ret = clk_prepare_enable(priv->clk); > + if (ret < 0) { > + dev_err(dev, "Failed to start clock\n"); > + goto error_ret; > + } > + if (priv->aclk) { > + ret = clk_prepare_enable(priv->aclk); > + if (ret < 0) { > + dev_err(dev, "Failed to start audio clock\n"); > + goto disable_clk; > + } > + } > + > + /* Output the SPI CLKOUT (if clk_div == 0 clock if OFF) */ > + ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0), > + DFSDM_CHCFGR1_CKOUTDIV_MASK, > + DFSDM_CHCFGR1_CKOUTDIV(clk_div)); > + if (ret < 0) > + goto disable_aclk; > + > + /* Global enable of DFSDM interface */ > + ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0), > + DFSDM_CHCFGR1_DFSDMEN_MASK, > + DFSDM_CHCFGR1_DFSDMEN(1)); > + if (ret < 0) > + goto disable_aclk; > + } > + > + dev_dbg(dev, "%s: n_active_ch %d\n", __func__, > + atomic_read(&priv->n_active_ch)); > + > + return 0; > + > +disable_aclk: > + clk_disable_unprepare(priv->aclk); > +disable_clk: > + clk_disable_unprepare(priv->clk); > + > +error_ret: > + atomic_dec(&priv->n_active_ch); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(stm32_dfsdm_start_dfsdm); > + > +/** > + * stm32_dfsdm_stop_dfsdm - stop global DFSDM interface. > + * > + * Disable interface if n_active_ch is null > + * @dfsdm: Handle used to retrieve dfsdm context. > + */ > +int stm32_dfsdm_stop_dfsdm(struct stm32_dfsdm *dfsdm) > +{ > + struct dfsdm_priv *priv = container_of(dfsdm, struct dfsdm_priv, dfsdm); > + int ret; > + > + if (atomic_dec_and_test(&priv->n_active_ch)) { > + /* Global disable of DFSDM interface */ > + ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0), > + DFSDM_CHCFGR1_DFSDMEN_MASK, > + DFSDM_CHCFGR1_DFSDMEN(0)); > + if (ret < 0) > + return ret; > + > + /* Stop SPI CLKOUT */ > + ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0), > + DFSDM_CHCFGR1_CKOUTDIV_MASK, > + DFSDM_CHCFGR1_CKOUTDIV(0)); > + if (ret < 0) > + return ret; > + > + clk_disable_unprepare(priv->clk); > + if (priv->aclk) > + clk_disable_unprepare(priv->aclk); > + } > + dev_dbg(&priv->pdev->dev, "%s: n_active_ch %d\n", __func__, > + atomic_read(&priv->n_active_ch)); > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(stm32_dfsdm_stop_dfsdm); > + > +static int stm32_dfsdm_parse_of(struct platform_device *pdev, > + struct dfsdm_priv *priv) > +{ > + struct device_node *node = pdev->dev.of_node; > + struct resource *res; > + unsigned long clk_freq; > + unsigned int spi_freq, rem; > + int ret; > + > + if (!node) > + return -EINVAL; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + if (!res) { > + dev_err(&pdev->dev, "Failed to get memory resource\n"); > + return -ENODEV; > + } > + priv->dfsdm.phys_base = res->start; > + priv->dfsdm.base = devm_ioremap_resource(&pdev->dev, res); > + > + /* > + * "dfsdm" clock is mandatory for DFSDM peripheral clocking. > + * "dfsdm" or "audio" clocks can be used as source clock for > + * the SPI clock out signal and internal processing, depending > + * on use case. > + */ > + priv->clk = devm_clk_get(&pdev->dev, "dfsdm"); > + if (IS_ERR(priv->clk)) { > + dev_err(&pdev->dev, "No stm32_dfsdm_clk clock found\n"); > + return -EINVAL; > + } > + > + priv->aclk = devm_clk_get(&pdev->dev, "audio"); > + if (IS_ERR(priv->aclk)) > + priv->aclk = NULL; > + > + if (priv->aclk) > + clk_freq = clk_get_rate(priv->aclk); > + else > + clk_freq = clk_get_rate(priv->clk); > + > + /* SPI clock out frequency */ > + ret = of_property_read_u32(pdev->dev.of_node, "spi-max-frequency", > + &spi_freq); > + if (ret < 0) { > + dev_err(&pdev->dev, "Failed to get spi-max-frequency\n"); > + return ret; > + } > + > + priv->spi_clk_out_div = div_u64_rem(clk_freq, spi_freq, &rem) - 1; > + priv->dfsdm.spi_master_freq = spi_freq; > + > + if (rem) { > + dev_warn(&pdev->dev, "SPI clock not accurate\n"); > + dev_warn(&pdev->dev, "%ld = %d * %d + %d\n", > + clk_freq, spi_freq, priv->spi_clk_out_div + 1, rem); > + } > + > + return 0; > +}; > + > +static const struct of_device_id stm32_dfsdm_of_match[] = { > + { > + .compatible = "st,stm32h7-dfsdm", > + .data = &stm32h7_dfsdm_data, > + }, > + {} > +}; > +MODULE_DEVICE_TABLE(of, stm32_dfsdm_of_match); > + > +static int stm32_dfsdm_probe(struct platform_device *pdev) > +{ > + struct dfsdm_priv *priv; > + struct device_node *pnode = pdev->dev.of_node; > + const struct of_device_id *of_id; > + const struct stm32_dfsdm_dev_data *dev_data; > + struct stm32_dfsdm *dfsdm; > + int ret; > + > + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + priv->pdev = pdev; > + > + of_id = of_match_node(stm32_dfsdm_of_match, pnode); > + 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; > + dfsdm = &priv->dfsdm; > + dfsdm->fl_list = devm_kcalloc(&pdev->dev, dev_data->num_filters, > + sizeof(*dfsdm->fl_list), GFP_KERNEL); > + if (!dfsdm->fl_list) > + return -ENOMEM; > + > + dfsdm->num_fls = dev_data->num_filters; > + dfsdm->ch_list = devm_kcalloc(&pdev->dev, dev_data->num_channels, > + sizeof(*dfsdm->ch_list), > + GFP_KERNEL); > + if (!dfsdm->ch_list) > + return -ENOMEM; > + dfsdm->num_chs = dev_data->num_channels; > + > + ret = stm32_dfsdm_parse_of(pdev, priv); > + if (ret < 0) > + return ret; > + > + dfsdm->regmap = devm_regmap_init_mmio(&pdev->dev, dfsdm->base, > + &stm32h7_dfsdm_regmap_cfg); > + if (IS_ERR(dfsdm->regmap)) { > + ret = PTR_ERR(dfsdm->regmap); > + dev_err(&pdev->dev, "%s: Failed to allocate regmap: %d\n", > + __func__, ret); > + return ret; > + } > + > + platform_set_drvdata(pdev, dfsdm); > + > + return devm_of_platform_populate(&pdev->dev); > +} > + > +static struct platform_driver stm32_dfsdm_driver = { > + .probe = stm32_dfsdm_probe, > + .driver = { > + .name = "stm32-dfsdm", > + .of_match_table = stm32_dfsdm_of_match, > + }, > +}; > + > +module_platform_driver(stm32_dfsdm_driver); > + > +MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>"); > +MODULE_DESCRIPTION("STMicroelectronics STM32 dfsdm driver"); > +MODULE_LICENSE("GPL v2"); > diff --git a/drivers/iio/adc/stm32-dfsdm.h b/drivers/iio/adc/stm32-dfsdm.h > new file mode 100644 > index 0000000..9990e8b > --- /dev/null > +++ b/drivers/iio/adc/stm32-dfsdm.h > @@ -0,0 +1,319 @@ > +/* > + * This file is part of STM32 DFSDM driver > + * > + * 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 MDF_STM32_DFSDM__H > +#define MDF_STM32_DFSDM__H > + > +#include <linux/bitfield.h> > + > +/* > + * STM32 DFSDM - global register map > + * ________________________________________________________ > + * | Offset | Registers block | > + * -------------------------------------------------------- > + * | 0x000 | CHANNEL 0 + COMMON CHANNEL FIELDS | > + * -------------------------------------------------------- > + * | 0x020 | CHANNEL 1 | > + * -------------------------------------------------------- > + * | ... | ..... | > + * -------------------------------------------------------- > + * | 0x0E0 | CHANNEL 7 | > + * -------------------------------------------------------- > + * | 0x100 | FILTER 0 + COMMON FILTER FIELDs | > + * -------------------------------------------------------- > + * | 0x200 | FILTER 1 | > + * -------------------------------------------------------- > + * | 0x300 | FILTER 2 | > + * -------------------------------------------------------- > + * | 0x400 | FILTER 3 | > + * -------------------------------------------------------- > + */ > + > +/* > + * Channels register definitions > + */ > +#define DFSDM_CHCFGR1(y) ((y) * 0x20 + 0x00) > +#define DFSDM_CHCFGR2(y) ((y) * 0x20 + 0x04) > +#define DFSDM_AWSCDR(y) ((y) * 0x20 + 0x08) > +#define DFSDM_CHWDATR(y) ((y) * 0x20 + 0x0C) > +#define DFSDM_CHDATINR(y) ((y) * 0x20 + 0x10) > + > +/* CHCFGR1: Channel configuration register 1 */ > +#define DFSDM_CHCFGR1_SITP_MASK GENMASK(1, 0) > +#define DFSDM_CHCFGR1_SITP(v) FIELD_PREP(DFSDM_CHCFGR1_SITP_MASK, v) > +#define DFSDM_CHCFGR1_SPICKSEL_MASK GENMASK(3, 2) > +#define DFSDM_CHCFGR1_SPICKSEL(v) FIELD_PREP(DFSDM_CHCFGR1_SPICKSEL_MASK, v) > +#define DFSDM_CHCFGR1_SCDEN_MASK BIT(5) > +#define DFSDM_CHCFGR1_SCDEN(v) FIELD_PREP(DFSDM_CHCFGR1_SCDEN_MASK, v) > +#define DFSDM_CHCFGR1_CKABEN_MASK BIT(6) > +#define DFSDM_CHCFGR1_CKABEN(v) FIELD_PREP(DFSDM_CHCFGR1_CKABEN_MASK, v) > +#define DFSDM_CHCFGR1_CHEN_MASK BIT(7) > +#define DFSDM_CHCFGR1_CHEN(v) FIELD_PREP(DFSDM_CHCFGR1_CHEN_MASK, v) > +#define DFSDM_CHCFGR1_CHINSEL_MASK BIT(8) > +#define DFSDM_CHCFGR1_CHINSEL(v) FIELD_PREP(DFSDM_CHCFGR1_CHINSEL_MASK, v) > +#define DFSDM_CHCFGR1_DATMPX_MASK GENMASK(13, 12) > +#define DFSDM_CHCFGR1_DATMPX(v) FIELD_PREP(DFSDM_CHCFGR1_DATMPX_MASK, v) > +#define DFSDM_CHCFGR1_DATPACK_MASK GENMASK(15, 14) > +#define DFSDM_CHCFGR1_DATPACK(v) FIELD_PREP(DFSDM_CHCFGR1_DATPACK_MASK, v) > +#define DFSDM_CHCFGR1_CKOUTDIV_MASK GENMASK(23, 16) > +#define DFSDM_CHCFGR1_CKOUTDIV(v) FIELD_PREP(DFSDM_CHCFGR1_CKOUTDIV_MASK, v) > +#define DFSDM_CHCFGR1_CKOUTSRC_MASK BIT(30) > +#define DFSDM_CHCFGR1_CKOUTSRC(v) FIELD_PREP(DFSDM_CHCFGR1_CKOUTSRC_MASK, v) > +#define DFSDM_CHCFGR1_DFSDMEN_MASK BIT(31) > +#define DFSDM_CHCFGR1_DFSDMEN(v) FIELD_PREP(DFSDM_CHCFGR1_DFSDMEN_MASK, v) > + > +/* CHCFGR2: Channel configuration register 2 */ > +#define DFSDM_CHCFGR2_DTRBS_MASK GENMASK(7, 3) > +#define DFSDM_CHCFGR2_DTRBS(v) FIELD_PREP(DFSDM_CHCFGR2_DTRBS_MASK, v) > +#define DFSDM_CHCFGR2_OFFSET_MASK GENMASK(31, 8) > +#define DFSDM_CHCFGR2_OFFSET(v) FIELD_PREP(DFSDM_CHCFGR2_OFFSET_MASK, v) > + > +/* AWSCDR: Channel analog watchdog and short circuit detector */ > +#define DFSDM_AWSCDR_SCDT_MASK GENMASK(7, 0) > +#define DFSDM_AWSCDR_SCDT(v) FIELD_PREP(DFSDM_AWSCDR_SCDT_MASK, v) > +#define DFSDM_AWSCDR_BKSCD_MASK GENMASK(15, 12) > +#define DFSDM_AWSCDR_BKSCD(v) FIELD_PREP(DFSDM_AWSCDR_BKSCD_MASK, v) > +#define DFSDM_AWSCDR_AWFOSR_MASK GENMASK(20, 16) > +#define DFSDM_AWSCDR_AWFOSR(v) FIELD_PREP(DFSDM_AWSCDR_AWFOSR_MASK, v) > +#define DFSDM_AWSCDR_AWFORD_MASK GENMASK(23, 22) > +#define DFSDM_AWSCDR_AWFORD(v) FIELD_PREP(DFSDM_AWSCDR_AWFORD_MASK, v) > + > +/* > + * Filters register definitions > + */ > +#define DFSDM_FILTER_BASE_ADR 0x100 > +#define DFSDM_FILTER_REG_MASK 0x7F > +#define DFSDM_FILTER_X_BASE_ADR(x) ((x) * 0x80 + DFSDM_FILTER_BASE_ADR) > + > +#define DFSDM_CR1(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x00) > +#define DFSDM_CR2(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x04) > +#define DFSDM_ISR(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x08) > +#define DFSDM_ICR(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x0C) > +#define DFSDM_JCHGR(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x10) > +#define DFSDM_FCR(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x14) > +#define DFSDM_JDATAR(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x18) > +#define DFSDM_RDATAR(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x1C) > +#define DFSDM_AWHTR(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x20) > +#define DFSDM_AWLTR(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x24) > +#define DFSDM_AWSR(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x28) > +#define DFSDM_AWCFR(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x2C) > +#define DFSDM_EXMAX(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x30) > +#define DFSDM_EXMIN(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x34) > +#define DFSDM_CNVTIMR(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x38) > + > +/* CR1 Control register 1 */ > +#define DFSDM_CR1_DFEN_MASK BIT(0) > +#define DFSDM_CR1_DFEN(v) FIELD_PREP(DFSDM_CR1_DFEN_MASK, v) > +#define DFSDM_CR1_JSWSTART_MASK BIT(1) > +#define DFSDM_CR1_JSWSTART(v) FIELD_PREP(DFSDM_CR1_JSWSTART_MASK, v) > +#define DFSDM_CR1_JSYNC_MASK BIT(3) > +#define DFSDM_CR1_JSYNC(v) FIELD_PREP(DFSDM_CR1_JSYNC_MASK, v) > +#define DFSDM_CR1_JSCAN_MASK BIT(4) > +#define DFSDM_CR1_JSCAN(v) FIELD_PREP(DFSDM_CR1_JSCAN_MASK, v) > +#define DFSDM_CR1_JDMAEN_MASK BIT(5) > +#define DFSDM_CR1_JDMAEN(v) FIELD_PREP(DFSDM_CR1_JDMAEN_MASK, v) > +#define DFSDM_CR1_JEXTSEL_MASK GENMASK(12, 8) > +#define DFSDM_CR1_JEXTSEL(v) FIELD_PREP(DFSDM_CR1_JEXTSEL_MASK, v) > +#define DFSDM_CR1_JEXTEN_MASK GENMASK(14, 13) > +#define DFSDM_CR1_JEXTEN(v) FIELD_PREP(DFSDM_CR1_JEXTEN_MASK, v) > +#define DFSDM_CR1_RSWSTART_MASK BIT(17) > +#define DFSDM_CR1_RSWSTART(v) FIELD_PREP(DFSDM_CR1_RSWSTART_MASK, v) > +#define DFSDM_CR1_RCONT_MASK BIT(18) > +#define DFSDM_CR1_RCONT(v) FIELD_PREP(DFSDM_CR1_RCONT_MASK, v) > +#define DFSDM_CR1_RSYNC_MASK BIT(19) > +#define DFSDM_CR1_RSYNC(v) FIELD_PREP(DFSDM_CR1_RSYNC_MASK, v) > +#define DFSDM_CR1_RDMAEN_MASK BIT(21) > +#define DFSDM_CR1_RDMAEN(v) FIELD_PREP(DFSDM_CR1_RDMAEN_MASK, v) > +#define DFSDM_CR1_RCH_MASK GENMASK(26, 24) > +#define DFSDM_CR1_RCH(v) FIELD_PREP(DFSDM_CR1_RCH_MASK, v) > +#define DFSDM_CR1_FAST_MASK BIT(29) > +#define DFSDM_CR1_FAST(v) FIELD_PREP(DFSDM_CR1_FAST_MASK, v) > +#define DFSDM_CR1_AWFSEL_MASK BIT(30) > +#define DFSDM_CR1_AWFSEL(v) FIELD_PREP(DFSDM_CR1_AWFSEL_MASK, v) > + > +/* CR2: Control register 2 */ > +#define DFSDM_CR2_IE_MASK GENMASK(6, 0) > +#define DFSDM_CR2_IE(v) FIELD_PREP(DFSDM_CR2_IE_MASK, v) > +#define DFSDM_CR2_JEOCIE_MASK BIT(0) > +#define DFSDM_CR2_JEOCIE(v) FIELD_PREP(DFSDM_CR2_JEOCIE_MASK, v) > +#define DFSDM_CR2_REOCIE_MASK BIT(1) > +#define DFSDM_CR2_REOCIE(v) FIELD_PREP(DFSDM_CR2_REOCIE_MASK, v) > +#define DFSDM_CR2_JOVRIE_MASK BIT(2) > +#define DFSDM_CR2_JOVRIE(v) FIELD_PREP(DFSDM_CR2_JOVRIE_MASK, v) > +#define DFSDM_CR2_ROVRIE_MASK BIT(3) > +#define DFSDM_CR2_ROVRIE(v) FIELD_PREP(DFSDM_CR2_ROVRIE_MASK, v) > +#define DFSDM_CR2_AWDIE_MASK BIT(4) > +#define DFSDM_CR2_AWDIE(v) FIELD_PREP(DFSDM_CR2_AWDIE_MASK, v) > +#define DFSDM_CR2_SCDIE_MASK BIT(5) > +#define DFSDM_CR2_SCDIE(v) FIELD_PREP(DFSDM_CR2_SCDIE_MASK, v) > +#define DFSDM_CR2_CKABIE_MASK BIT(6) > +#define DFSDM_CR2_CKABIE(v) FIELD_PREP(DFSDM_CR2_CKABIE_MASK, v) > +#define DFSDM_CR2_EXCH_MASK GENMASK(15, 8) > +#define DFSDM_CR2_EXCH(v) FIELD_PREP(DFSDM_CR2_EXCH_MASK, v) > +#define DFSDM_CR2_AWDCH_MASK GENMASK(23, 16) > +#define DFSDM_CR2_AWDCH(v) FIELD_PREP(DFSDM_CR2_AWDCH_MASK, v) > + > +/* ISR: Interrupt status register */ > +#define DFSDM_ISR_JEOCF_MASK BIT(0) > +#define DFSDM_ISR_JEOCF(v) FIELD_PREP(DFSDM_ISR_JEOCF_MASK, v) > +#define DFSDM_ISR_REOCF_MASK BIT(1) > +#define DFSDM_ISR_REOCF(v) FIELD_PREP(DFSDM_ISR_REOCF_MASK, v) > +#define DFSDM_ISR_JOVRF_MASK BIT(2) > +#define DFSDM_ISR_JOVRF(v) FIELD_PREP(DFSDM_ISR_JOVRF_MASK, v) > +#define DFSDM_ISR_ROVRF_MASK BIT(3) > +#define DFSDM_ISR_ROVRF(v) FIELD_PREP(DFSDM_ISR_ROVRF_MASK, v) > +#define DFSDM_ISR_AWDF_MASK BIT(4) > +#define DFSDM_ISR_AWDF(v) FIELD_PREP(DFSDM_ISR_AWDF_MASK, v) > +#define DFSDM_ISR_JCIP_MASK BIT(13) > +#define DFSDM_ISR_JCIP(v) FIELD_PREP(DFSDM_ISR_JCIP_MASK, v) > +#define DFSDM_ISR_RCIP_MASK BIT(14) > +#define DFSDM_ISR_RCIP(v) FIELD_PREP(DFSDM_ISR_RCIP, v) > +#define DFSDM_ISR_CKABF_MASK GENMASK(23, 16) > +#define DFSDM_ISR_CKABF(v) FIELD_PREP(DFSDM_ISR_CKABF_MASK, v) > +#define DFSDM_ISR_SCDF_MASK GENMASK(31, 24) > +#define DFSDM_ISR_SCDF(v) FIELD_PREP(DFSDM_ISR_SCDF_MASK, v) > + > +/* ICR: Interrupt flag clear register */ > +#define DFSDM_ICR_CLRJOVRF_MASK BIT(2) > +#define DFSDM_ICR_CLRJOVRF(v) FIELD_PREP(DFSDM_ICR_CLRJOVRF_MASK, v) > +#define DFSDM_ICR_CLRROVRF_MASK BIT(3) > +#define DFSDM_ICR_CLRROVRF(v) FIELD_PREP(DFSDM_ICR_CLRROVRF_MASK, v) > +#define DFSDM_ICR_CLRCKABF_MASK GENMASK(23, 16) > +#define DFSDM_ICR_CLRCKABF(v) FIELD_PREP(DFSDM_ICR_CLRCKABF_MASK, v) > +#define DFSDM_ICR_CLRCKABF_CH_MASK(y) BIT(16 + (y)) > +#define DFSDM_ICR_CLRCKABF_CH(v, y) \ > + (((v) << (16 + (y))) & DFSDM_ICR_CLRCKABF_CH_MASK(y)) > +#define DFSDM_ICR_CLRSCDF_MASK GENMASK(31, 24) > +#define DFSDM_ICR_CLRSCDF(v) FIELD_PREP(DFSDM_ICR_CLRSCDF_MASK, v) > +#define DFSDM_ICR_CLRSCDF_CH_MASK(y) BIT(24 + (y)) > +#define DFSDM_ICR_CLRSCDF_CH(v, y) \ > + (((v) << (24 + (y))) & DFSDM_ICR_CLRSCDF_MASK(y)) > + > +/* FCR: Filter control register */ > +#define DFSDM_FCR_IOSR_MASK GENMASK(7, 0) > +#define DFSDM_FCR_IOSR(v) FIELD_PREP(DFSDM_FCR_IOSR_MASK, v) > +#define DFSDM_FCR_FOSR_MASK GENMASK(25, 16) > +#define DFSDM_FCR_FOSR(v) FIELD_PREP(DFSDM_FCR_FOSR_MASK, v) > +#define DFSDM_FCR_FORD_MASK GENMASK(31, 29) > +#define DFSDM_FCR_FORD(v) FIELD_PREP(DFSDM_FCR_FORD_MASK, v) > + > +/* RDATAR: Filter data register for regular channel */ > +#define DFSDM_DATAR_CH_MASK GENMASK(2, 0) > +#define DFSDM_DATAR_DATA_OFFSET 8 > +#define DFSDM_DATAR_DATA_MASK GENMASK(31, DFSDM_DATAR_DATA_OFFSET) > + > +/* AWLTR: Filter analog watchdog low threshold register */ > +#define DFSDM_AWLTR_BKAWL_MASK GENMASK(3, 0) > +#define DFSDM_AWLTR_BKAWL(v) FIELD_PREP(DFSDM_AWLTR_BKAWL_MASK, v) > +#define DFSDM_AWLTR_AWLT_MASK GENMASK(31, 8) > +#define DFSDM_AWLTR_AWLT(v) FIELD_PREP(DFSDM_AWLTR_AWLT_MASK, v) > + > +/* AWHTR: Filter analog watchdog low threshold register */ > +#define DFSDM_AWHTR_BKAWH_MASK GENMASK(3, 0) > +#define DFSDM_AWHTR_BKAWH(v) FIELD_PREP(DFSDM_AWHTR_BKAWH_MASK, v) > +#define DFSDM_AWHTR_AWHT_MASK GENMASK(31, 8) > +#define DFSDM_AWHTR_AWHT(v) FIELD_PREP(DFSDM_AWHTR_AWHT_MASK, v) > + > +/* AWSR: Filter watchdog status register */ > +#define DFSDM_AWSR_AWLTF_MASK GENMASK(7, 0) > +#define DFSDM_AWSR_AWLTF(v) FIELD_PREP(DFSDM_AWSR_AWLTF_MASK, v) > +#define DFSDM_AWSR_AWHTF_MASK GENMASK(15, 8) > +#define DFSDM_AWSR_AWHTF(v) FIELD_PREP(DFSDM_AWSR_AWHTF_MASK, v) > + > +/* AWCFR: Filter watchdog status register */ > +#define DFSDM_AWCFR_AWLTF_MASK GENMASK(7, 0) > +#define DFSDM_AWCFR_AWLTF(v) FIELD_PREP(DFSDM_AWCFR_AWLTF_MASK, v) > +#define DFSDM_AWCFR_AWHTF_MASK GENMASK(15, 8) > +#define DFSDM_AWCFR_AWHTF(v) FIELD_PREP(DFSDM_AWCFR_AWHTF_MASK, v) > + > +/* DFSDM filter order */ > +enum stm32_dfsdm_sinc_order { > + DFSDM_FASTSINC_ORDER, /* FastSinc filter type */ > + DFSDM_SINC1_ORDER, /* Sinc 1 filter type */ > + DFSDM_SINC2_ORDER, /* Sinc 2 filter type */ > + DFSDM_SINC3_ORDER, /* Sinc 3 filter type */ > + DFSDM_SINC4_ORDER, /* Sinc 4 filter type (N.A. for watchdog) */ > + DFSDM_SINC5_ORDER, /* Sinc 5 filter type (N.A. for watchdog) */ > + DFSDM_NB_SINC_ORDER, > +}; > + > +/** > + * struct stm32_dfsdm_filter - structure relative to stm32 FDSDM filter > + * @iosr: integrator oversampling > + * @fosr: filter oversampling > + * @ford: filter order > + * @res: output sample resolution > + * @sync_mode: filter synchronized with filter 0 > + * @fast: filter fast mode > + */ > +struct stm32_dfsdm_filter { > + unsigned int iosr; > + unsigned int fosr; > + enum stm32_dfsdm_sinc_order ford; > + u64 res; > + unsigned int sync_mode; > + unsigned int fast; > +}; > + > +/** > + * struct stm32_dfsdm_channel - structure relative to stm32 FDSDM channel > + * @id: id of the channel > + * @type: interface type linked to stm32_dfsdm_chan_type > + * @src: interface type linked to stm32_dfsdm_chan_src > + * @alt_si: alternative serial input interface > + */ > +struct stm32_dfsdm_channel { > + unsigned int id; > + unsigned int type; > + unsigned int src; > + unsigned int alt_si; > +}; > + > +/** > + * struct stm32_dfsdm - stm32 FDSDM driver common data (for all instances) > + * @base: control registers base cpu addr > + * @phys_base: DFSDM IP register physical address > + * @regmap: regmap for register read/write > + * @fl_list: filter resources list > + * @num_fls: number of filter resources available > + * @ch_list: channel resources list > + * @num_chs: number of channel resources available > + * @spi_master_freq: SPI clock out frequency > + */ > +struct stm32_dfsdm { > + void __iomem *base; > + phys_addr_t phys_base; > + struct regmap *regmap; > + struct stm32_dfsdm_filter *fl_list; > + unsigned int num_fls; > + struct stm32_dfsdm_channel *ch_list; > + unsigned int num_chs; > + unsigned int spi_master_freq; > +}; > + > +/* DFSDM channel serial spi clock source */ > +enum stm32_dfsdm_spi_clk_src { > + DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL, > + DFSDM_CHANNEL_SPI_CLOCK_INTERNAL, > + DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_FALLING, > + DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_RISING > +}; > + > +int stm32_dfsdm_start_dfsdm(struct stm32_dfsdm *dfsdm); > +int stm32_dfsdm_stop_dfsdm(struct stm32_dfsdm *dfsdm); > + > +#endif -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index c5db62f..b729ae0 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -665,6 +665,18 @@ config STM32_ADC This driver can also be built as a module. If so, the module will be called stm32-adc. +config STM32_DFSDM_CORE + tristate "STMicroelectronics STM32 DFSDM core" + depends on (ARCH_STM32 && OF) || COMPILE_TEST + select REGMAP + select REGMAP_MMIO + help + Select this option to enable the driver 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-core. + 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 d800325..b52d0a0 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -63,6 +63,7 @@ obj-$(CONFIG_STX104) += stx104.o obj-$(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_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-core.c b/drivers/iio/adc/stm32-dfsdm-core.c new file mode 100644 index 0000000..0be5155 --- /dev/null +++ b/drivers/iio/adc/stm32-dfsdm-core.c @@ -0,0 +1,318 @@ +/* + * This file is part the core part STM32 DFSDM driver + * + * Copyright (C) 2017, STMicroelectronics - All Rights Reserved + * Author(s): Arnaud Pouliquen <arnaud.pouliquen@st.com> for STMicroelectronics. + * + * 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. + */ + +#include <linux/clk.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/regmap.h> +#include <linux/slab.h> + +#include "stm32-dfsdm.h" + +struct stm32_dfsdm_dev_data { + unsigned int num_filters; + unsigned int num_channels; + const struct regmap_config *regmap_cfg; +}; + +#define STM32H7_DFSDM_NUM_FILTERS 4 +#define STM32H7_DFSDM_NUM_CHANNELS 8 + +static bool stm32_dfsdm_volatile_reg(struct device *dev, unsigned int reg) +{ + if (reg < DFSDM_FILTER_BASE_ADR) + return false; + + /* + * Mask is done on register to avoid to list registers of all + * filter instances. + */ + switch (reg & DFSDM_FILTER_REG_MASK) { + case DFSDM_CR1(0) & DFSDM_FILTER_REG_MASK: + case DFSDM_ISR(0) & DFSDM_FILTER_REG_MASK: + case DFSDM_JDATAR(0) & DFSDM_FILTER_REG_MASK: + case DFSDM_RDATAR(0) & DFSDM_FILTER_REG_MASK: + return true; + } + + return false; +} + +static const struct regmap_config stm32h7_dfsdm_regmap_cfg = { + .reg_bits = 32, + .val_bits = 32, + .reg_stride = sizeof(u32), + .max_register = 0x2B8, + .volatile_reg = stm32_dfsdm_volatile_reg, + .fast_io = true, +}; + +static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_data = { + .num_filters = STM32H7_DFSDM_NUM_FILTERS, + .num_channels = STM32H7_DFSDM_NUM_CHANNELS, + .regmap_cfg = &stm32h7_dfsdm_regmap_cfg, +}; + +struct dfsdm_priv { + struct platform_device *pdev; /* platform device */ + + struct stm32_dfsdm dfsdm; /* common data exported for all instances */ + + unsigned int spi_clk_out_div; /* SPI clkout divider value */ + atomic_t n_active_ch; /* number of current active channels */ + + struct clk *clk; /* DFSDM clock */ + struct clk *aclk; /* audio clock */ +}; + +/** + * stm32_dfsdm_start_dfsdm - start global dfsdm interface. + * + * Enable interface if n_active_ch is not null. + * @dfsdm: Handle used to retrieve dfsdm context. + */ +int stm32_dfsdm_start_dfsdm(struct stm32_dfsdm *dfsdm) +{ + struct dfsdm_priv *priv = container_of(dfsdm, struct dfsdm_priv, dfsdm); + struct device *dev = &priv->pdev->dev; + unsigned int clk_div = priv->spi_clk_out_div; + int ret; + + if (atomic_inc_return(&priv->n_active_ch) == 1) { + ret = clk_prepare_enable(priv->clk); + if (ret < 0) { + dev_err(dev, "Failed to start clock\n"); + goto error_ret; + } + if (priv->aclk) { + ret = clk_prepare_enable(priv->aclk); + if (ret < 0) { + dev_err(dev, "Failed to start audio clock\n"); + goto disable_clk; + } + } + + /* Output the SPI CLKOUT (if clk_div == 0 clock if OFF) */ + ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0), + DFSDM_CHCFGR1_CKOUTDIV_MASK, + DFSDM_CHCFGR1_CKOUTDIV(clk_div)); + if (ret < 0) + goto disable_aclk; + + /* Global enable of DFSDM interface */ + ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0), + DFSDM_CHCFGR1_DFSDMEN_MASK, + DFSDM_CHCFGR1_DFSDMEN(1)); + if (ret < 0) + goto disable_aclk; + } + + dev_dbg(dev, "%s: n_active_ch %d\n", __func__, + atomic_read(&priv->n_active_ch)); + + return 0; + +disable_aclk: + clk_disable_unprepare(priv->aclk); +disable_clk: + clk_disable_unprepare(priv->clk); + +error_ret: + atomic_dec(&priv->n_active_ch); + + return ret; +} +EXPORT_SYMBOL_GPL(stm32_dfsdm_start_dfsdm); + +/** + * stm32_dfsdm_stop_dfsdm - stop global DFSDM interface. + * + * Disable interface if n_active_ch is null + * @dfsdm: Handle used to retrieve dfsdm context. + */ +int stm32_dfsdm_stop_dfsdm(struct stm32_dfsdm *dfsdm) +{ + struct dfsdm_priv *priv = container_of(dfsdm, struct dfsdm_priv, dfsdm); + int ret; + + if (atomic_dec_and_test(&priv->n_active_ch)) { + /* Global disable of DFSDM interface */ + ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0), + DFSDM_CHCFGR1_DFSDMEN_MASK, + DFSDM_CHCFGR1_DFSDMEN(0)); + if (ret < 0) + return ret; + + /* Stop SPI CLKOUT */ + ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0), + DFSDM_CHCFGR1_CKOUTDIV_MASK, + DFSDM_CHCFGR1_CKOUTDIV(0)); + if (ret < 0) + return ret; + + clk_disable_unprepare(priv->clk); + if (priv->aclk) + clk_disable_unprepare(priv->aclk); + } + dev_dbg(&priv->pdev->dev, "%s: n_active_ch %d\n", __func__, + atomic_read(&priv->n_active_ch)); + + return 0; +} +EXPORT_SYMBOL_GPL(stm32_dfsdm_stop_dfsdm); + +static int stm32_dfsdm_parse_of(struct platform_device *pdev, + struct dfsdm_priv *priv) +{ + struct device_node *node = pdev->dev.of_node; + struct resource *res; + unsigned long clk_freq; + unsigned int spi_freq, rem; + int ret; + + if (!node) + return -EINVAL; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + dev_err(&pdev->dev, "Failed to get memory resource\n"); + return -ENODEV; + } + priv->dfsdm.phys_base = res->start; + priv->dfsdm.base = devm_ioremap_resource(&pdev->dev, res); + + /* + * "dfsdm" clock is mandatory for DFSDM peripheral clocking. + * "dfsdm" or "audio" clocks can be used as source clock for + * the SPI clock out signal and internal processing, depending + * on use case. + */ + priv->clk = devm_clk_get(&pdev->dev, "dfsdm"); + if (IS_ERR(priv->clk)) { + dev_err(&pdev->dev, "No stm32_dfsdm_clk clock found\n"); + return -EINVAL; + } + + priv->aclk = devm_clk_get(&pdev->dev, "audio"); + if (IS_ERR(priv->aclk)) + priv->aclk = NULL; + + if (priv->aclk) + clk_freq = clk_get_rate(priv->aclk); + else + clk_freq = clk_get_rate(priv->clk); + + /* SPI clock out frequency */ + ret = of_property_read_u32(pdev->dev.of_node, "spi-max-frequency", + &spi_freq); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to get spi-max-frequency\n"); + return ret; + } + + priv->spi_clk_out_div = div_u64_rem(clk_freq, spi_freq, &rem) - 1; + priv->dfsdm.spi_master_freq = spi_freq; + + if (rem) { + dev_warn(&pdev->dev, "SPI clock not accurate\n"); + dev_warn(&pdev->dev, "%ld = %d * %d + %d\n", + clk_freq, spi_freq, priv->spi_clk_out_div + 1, rem); + } + + return 0; +}; + +static const struct of_device_id stm32_dfsdm_of_match[] = { + { + .compatible = "st,stm32h7-dfsdm", + .data = &stm32h7_dfsdm_data, + }, + {} +}; +MODULE_DEVICE_TABLE(of, stm32_dfsdm_of_match); + +static int stm32_dfsdm_probe(struct platform_device *pdev) +{ + struct dfsdm_priv *priv; + struct device_node *pnode = pdev->dev.of_node; + const struct of_device_id *of_id; + const struct stm32_dfsdm_dev_data *dev_data; + struct stm32_dfsdm *dfsdm; + int ret; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->pdev = pdev; + + of_id = of_match_node(stm32_dfsdm_of_match, pnode); + 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; + dfsdm = &priv->dfsdm; + dfsdm->fl_list = devm_kcalloc(&pdev->dev, dev_data->num_filters, + sizeof(*dfsdm->fl_list), GFP_KERNEL); + if (!dfsdm->fl_list) + return -ENOMEM; + + dfsdm->num_fls = dev_data->num_filters; + dfsdm->ch_list = devm_kcalloc(&pdev->dev, dev_data->num_channels, + sizeof(*dfsdm->ch_list), + GFP_KERNEL); + if (!dfsdm->ch_list) + return -ENOMEM; + dfsdm->num_chs = dev_data->num_channels; + + ret = stm32_dfsdm_parse_of(pdev, priv); + if (ret < 0) + return ret; + + dfsdm->regmap = devm_regmap_init_mmio(&pdev->dev, dfsdm->base, + &stm32h7_dfsdm_regmap_cfg); + if (IS_ERR(dfsdm->regmap)) { + ret = PTR_ERR(dfsdm->regmap); + dev_err(&pdev->dev, "%s: Failed to allocate regmap: %d\n", + __func__, ret); + return ret; + } + + platform_set_drvdata(pdev, dfsdm); + + return devm_of_platform_populate(&pdev->dev); +} + +static struct platform_driver stm32_dfsdm_driver = { + .probe = stm32_dfsdm_probe, + .driver = { + .name = "stm32-dfsdm", + .of_match_table = stm32_dfsdm_of_match, + }, +}; + +module_platform_driver(stm32_dfsdm_driver); + +MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>"); +MODULE_DESCRIPTION("STMicroelectronics STM32 dfsdm driver"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/iio/adc/stm32-dfsdm.h b/drivers/iio/adc/stm32-dfsdm.h new file mode 100644 index 0000000..9990e8b --- /dev/null +++ b/drivers/iio/adc/stm32-dfsdm.h @@ -0,0 +1,319 @@ +/* + * This file is part of STM32 DFSDM driver + * + * 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 MDF_STM32_DFSDM__H +#define MDF_STM32_DFSDM__H + +#include <linux/bitfield.h> + +/* + * STM32 DFSDM - global register map + * ________________________________________________________ + * | Offset | Registers block | + * -------------------------------------------------------- + * | 0x000 | CHANNEL 0 + COMMON CHANNEL FIELDS | + * -------------------------------------------------------- + * | 0x020 | CHANNEL 1 | + * -------------------------------------------------------- + * | ... | ..... | + * -------------------------------------------------------- + * | 0x0E0 | CHANNEL 7 | + * -------------------------------------------------------- + * | 0x100 | FILTER 0 + COMMON FILTER FIELDs | + * -------------------------------------------------------- + * | 0x200 | FILTER 1 | + * -------------------------------------------------------- + * | 0x300 | FILTER 2 | + * -------------------------------------------------------- + * | 0x400 | FILTER 3 | + * -------------------------------------------------------- + */ + +/* + * Channels register definitions + */ +#define DFSDM_CHCFGR1(y) ((y) * 0x20 + 0x00) +#define DFSDM_CHCFGR2(y) ((y) * 0x20 + 0x04) +#define DFSDM_AWSCDR(y) ((y) * 0x20 + 0x08) +#define DFSDM_CHWDATR(y) ((y) * 0x20 + 0x0C) +#define DFSDM_CHDATINR(y) ((y) * 0x20 + 0x10) + +/* CHCFGR1: Channel configuration register 1 */ +#define DFSDM_CHCFGR1_SITP_MASK GENMASK(1, 0) +#define DFSDM_CHCFGR1_SITP(v) FIELD_PREP(DFSDM_CHCFGR1_SITP_MASK, v) +#define DFSDM_CHCFGR1_SPICKSEL_MASK GENMASK(3, 2) +#define DFSDM_CHCFGR1_SPICKSEL(v) FIELD_PREP(DFSDM_CHCFGR1_SPICKSEL_MASK, v) +#define DFSDM_CHCFGR1_SCDEN_MASK BIT(5) +#define DFSDM_CHCFGR1_SCDEN(v) FIELD_PREP(DFSDM_CHCFGR1_SCDEN_MASK, v) +#define DFSDM_CHCFGR1_CKABEN_MASK BIT(6) +#define DFSDM_CHCFGR1_CKABEN(v) FIELD_PREP(DFSDM_CHCFGR1_CKABEN_MASK, v) +#define DFSDM_CHCFGR1_CHEN_MASK BIT(7) +#define DFSDM_CHCFGR1_CHEN(v) FIELD_PREP(DFSDM_CHCFGR1_CHEN_MASK, v) +#define DFSDM_CHCFGR1_CHINSEL_MASK BIT(8) +#define DFSDM_CHCFGR1_CHINSEL(v) FIELD_PREP(DFSDM_CHCFGR1_CHINSEL_MASK, v) +#define DFSDM_CHCFGR1_DATMPX_MASK GENMASK(13, 12) +#define DFSDM_CHCFGR1_DATMPX(v) FIELD_PREP(DFSDM_CHCFGR1_DATMPX_MASK, v) +#define DFSDM_CHCFGR1_DATPACK_MASK GENMASK(15, 14) +#define DFSDM_CHCFGR1_DATPACK(v) FIELD_PREP(DFSDM_CHCFGR1_DATPACK_MASK, v) +#define DFSDM_CHCFGR1_CKOUTDIV_MASK GENMASK(23, 16) +#define DFSDM_CHCFGR1_CKOUTDIV(v) FIELD_PREP(DFSDM_CHCFGR1_CKOUTDIV_MASK, v) +#define DFSDM_CHCFGR1_CKOUTSRC_MASK BIT(30) +#define DFSDM_CHCFGR1_CKOUTSRC(v) FIELD_PREP(DFSDM_CHCFGR1_CKOUTSRC_MASK, v) +#define DFSDM_CHCFGR1_DFSDMEN_MASK BIT(31) +#define DFSDM_CHCFGR1_DFSDMEN(v) FIELD_PREP(DFSDM_CHCFGR1_DFSDMEN_MASK, v) + +/* CHCFGR2: Channel configuration register 2 */ +#define DFSDM_CHCFGR2_DTRBS_MASK GENMASK(7, 3) +#define DFSDM_CHCFGR2_DTRBS(v) FIELD_PREP(DFSDM_CHCFGR2_DTRBS_MASK, v) +#define DFSDM_CHCFGR2_OFFSET_MASK GENMASK(31, 8) +#define DFSDM_CHCFGR2_OFFSET(v) FIELD_PREP(DFSDM_CHCFGR2_OFFSET_MASK, v) + +/* AWSCDR: Channel analog watchdog and short circuit detector */ +#define DFSDM_AWSCDR_SCDT_MASK GENMASK(7, 0) +#define DFSDM_AWSCDR_SCDT(v) FIELD_PREP(DFSDM_AWSCDR_SCDT_MASK, v) +#define DFSDM_AWSCDR_BKSCD_MASK GENMASK(15, 12) +#define DFSDM_AWSCDR_BKSCD(v) FIELD_PREP(DFSDM_AWSCDR_BKSCD_MASK, v) +#define DFSDM_AWSCDR_AWFOSR_MASK GENMASK(20, 16) +#define DFSDM_AWSCDR_AWFOSR(v) FIELD_PREP(DFSDM_AWSCDR_AWFOSR_MASK, v) +#define DFSDM_AWSCDR_AWFORD_MASK GENMASK(23, 22) +#define DFSDM_AWSCDR_AWFORD(v) FIELD_PREP(DFSDM_AWSCDR_AWFORD_MASK, v) + +/* + * Filters register definitions + */ +#define DFSDM_FILTER_BASE_ADR 0x100 +#define DFSDM_FILTER_REG_MASK 0x7F +#define DFSDM_FILTER_X_BASE_ADR(x) ((x) * 0x80 + DFSDM_FILTER_BASE_ADR) + +#define DFSDM_CR1(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x00) +#define DFSDM_CR2(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x04) +#define DFSDM_ISR(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x08) +#define DFSDM_ICR(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x0C) +#define DFSDM_JCHGR(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x10) +#define DFSDM_FCR(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x14) +#define DFSDM_JDATAR(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x18) +#define DFSDM_RDATAR(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x1C) +#define DFSDM_AWHTR(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x20) +#define DFSDM_AWLTR(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x24) +#define DFSDM_AWSR(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x28) +#define DFSDM_AWCFR(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x2C) +#define DFSDM_EXMAX(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x30) +#define DFSDM_EXMIN(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x34) +#define DFSDM_CNVTIMR(x) (DFSDM_FILTER_X_BASE_ADR(x) + 0x38) + +/* CR1 Control register 1 */ +#define DFSDM_CR1_DFEN_MASK BIT(0) +#define DFSDM_CR1_DFEN(v) FIELD_PREP(DFSDM_CR1_DFEN_MASK, v) +#define DFSDM_CR1_JSWSTART_MASK BIT(1) +#define DFSDM_CR1_JSWSTART(v) FIELD_PREP(DFSDM_CR1_JSWSTART_MASK, v) +#define DFSDM_CR1_JSYNC_MASK BIT(3) +#define DFSDM_CR1_JSYNC(v) FIELD_PREP(DFSDM_CR1_JSYNC_MASK, v) +#define DFSDM_CR1_JSCAN_MASK BIT(4) +#define DFSDM_CR1_JSCAN(v) FIELD_PREP(DFSDM_CR1_JSCAN_MASK, v) +#define DFSDM_CR1_JDMAEN_MASK BIT(5) +#define DFSDM_CR1_JDMAEN(v) FIELD_PREP(DFSDM_CR1_JDMAEN_MASK, v) +#define DFSDM_CR1_JEXTSEL_MASK GENMASK(12, 8) +#define DFSDM_CR1_JEXTSEL(v) FIELD_PREP(DFSDM_CR1_JEXTSEL_MASK, v) +#define DFSDM_CR1_JEXTEN_MASK GENMASK(14, 13) +#define DFSDM_CR1_JEXTEN(v) FIELD_PREP(DFSDM_CR1_JEXTEN_MASK, v) +#define DFSDM_CR1_RSWSTART_MASK BIT(17) +#define DFSDM_CR1_RSWSTART(v) FIELD_PREP(DFSDM_CR1_RSWSTART_MASK, v) +#define DFSDM_CR1_RCONT_MASK BIT(18) +#define DFSDM_CR1_RCONT(v) FIELD_PREP(DFSDM_CR1_RCONT_MASK, v) +#define DFSDM_CR1_RSYNC_MASK BIT(19) +#define DFSDM_CR1_RSYNC(v) FIELD_PREP(DFSDM_CR1_RSYNC_MASK, v) +#define DFSDM_CR1_RDMAEN_MASK BIT(21) +#define DFSDM_CR1_RDMAEN(v) FIELD_PREP(DFSDM_CR1_RDMAEN_MASK, v) +#define DFSDM_CR1_RCH_MASK GENMASK(26, 24) +#define DFSDM_CR1_RCH(v) FIELD_PREP(DFSDM_CR1_RCH_MASK, v) +#define DFSDM_CR1_FAST_MASK BIT(29) +#define DFSDM_CR1_FAST(v) FIELD_PREP(DFSDM_CR1_FAST_MASK, v) +#define DFSDM_CR1_AWFSEL_MASK BIT(30) +#define DFSDM_CR1_AWFSEL(v) FIELD_PREP(DFSDM_CR1_AWFSEL_MASK, v) + +/* CR2: Control register 2 */ +#define DFSDM_CR2_IE_MASK GENMASK(6, 0) +#define DFSDM_CR2_IE(v) FIELD_PREP(DFSDM_CR2_IE_MASK, v) +#define DFSDM_CR2_JEOCIE_MASK BIT(0) +#define DFSDM_CR2_JEOCIE(v) FIELD_PREP(DFSDM_CR2_JEOCIE_MASK, v) +#define DFSDM_CR2_REOCIE_MASK BIT(1) +#define DFSDM_CR2_REOCIE(v) FIELD_PREP(DFSDM_CR2_REOCIE_MASK, v) +#define DFSDM_CR2_JOVRIE_MASK BIT(2) +#define DFSDM_CR2_JOVRIE(v) FIELD_PREP(DFSDM_CR2_JOVRIE_MASK, v) +#define DFSDM_CR2_ROVRIE_MASK BIT(3) +#define DFSDM_CR2_ROVRIE(v) FIELD_PREP(DFSDM_CR2_ROVRIE_MASK, v) +#define DFSDM_CR2_AWDIE_MASK BIT(4) +#define DFSDM_CR2_AWDIE(v) FIELD_PREP(DFSDM_CR2_AWDIE_MASK, v) +#define DFSDM_CR2_SCDIE_MASK BIT(5) +#define DFSDM_CR2_SCDIE(v) FIELD_PREP(DFSDM_CR2_SCDIE_MASK, v) +#define DFSDM_CR2_CKABIE_MASK BIT(6) +#define DFSDM_CR2_CKABIE(v) FIELD_PREP(DFSDM_CR2_CKABIE_MASK, v) +#define DFSDM_CR2_EXCH_MASK GENMASK(15, 8) +#define DFSDM_CR2_EXCH(v) FIELD_PREP(DFSDM_CR2_EXCH_MASK, v) +#define DFSDM_CR2_AWDCH_MASK GENMASK(23, 16) +#define DFSDM_CR2_AWDCH(v) FIELD_PREP(DFSDM_CR2_AWDCH_MASK, v) + +/* ISR: Interrupt status register */ +#define DFSDM_ISR_JEOCF_MASK BIT(0) +#define DFSDM_ISR_JEOCF(v) FIELD_PREP(DFSDM_ISR_JEOCF_MASK, v) +#define DFSDM_ISR_REOCF_MASK BIT(1) +#define DFSDM_ISR_REOCF(v) FIELD_PREP(DFSDM_ISR_REOCF_MASK, v) +#define DFSDM_ISR_JOVRF_MASK BIT(2) +#define DFSDM_ISR_JOVRF(v) FIELD_PREP(DFSDM_ISR_JOVRF_MASK, v) +#define DFSDM_ISR_ROVRF_MASK BIT(3) +#define DFSDM_ISR_ROVRF(v) FIELD_PREP(DFSDM_ISR_ROVRF_MASK, v) +#define DFSDM_ISR_AWDF_MASK BIT(4) +#define DFSDM_ISR_AWDF(v) FIELD_PREP(DFSDM_ISR_AWDF_MASK, v) +#define DFSDM_ISR_JCIP_MASK BIT(13) +#define DFSDM_ISR_JCIP(v) FIELD_PREP(DFSDM_ISR_JCIP_MASK, v) +#define DFSDM_ISR_RCIP_MASK BIT(14) +#define DFSDM_ISR_RCIP(v) FIELD_PREP(DFSDM_ISR_RCIP, v) +#define DFSDM_ISR_CKABF_MASK GENMASK(23, 16) +#define DFSDM_ISR_CKABF(v) FIELD_PREP(DFSDM_ISR_CKABF_MASK, v) +#define DFSDM_ISR_SCDF_MASK GENMASK(31, 24) +#define DFSDM_ISR_SCDF(v) FIELD_PREP(DFSDM_ISR_SCDF_MASK, v) + +/* ICR: Interrupt flag clear register */ +#define DFSDM_ICR_CLRJOVRF_MASK BIT(2) +#define DFSDM_ICR_CLRJOVRF(v) FIELD_PREP(DFSDM_ICR_CLRJOVRF_MASK, v) +#define DFSDM_ICR_CLRROVRF_MASK BIT(3) +#define DFSDM_ICR_CLRROVRF(v) FIELD_PREP(DFSDM_ICR_CLRROVRF_MASK, v) +#define DFSDM_ICR_CLRCKABF_MASK GENMASK(23, 16) +#define DFSDM_ICR_CLRCKABF(v) FIELD_PREP(DFSDM_ICR_CLRCKABF_MASK, v) +#define DFSDM_ICR_CLRCKABF_CH_MASK(y) BIT(16 + (y)) +#define DFSDM_ICR_CLRCKABF_CH(v, y) \ + (((v) << (16 + (y))) & DFSDM_ICR_CLRCKABF_CH_MASK(y)) +#define DFSDM_ICR_CLRSCDF_MASK GENMASK(31, 24) +#define DFSDM_ICR_CLRSCDF(v) FIELD_PREP(DFSDM_ICR_CLRSCDF_MASK, v) +#define DFSDM_ICR_CLRSCDF_CH_MASK(y) BIT(24 + (y)) +#define DFSDM_ICR_CLRSCDF_CH(v, y) \ + (((v) << (24 + (y))) & DFSDM_ICR_CLRSCDF_MASK(y)) + +/* FCR: Filter control register */ +#define DFSDM_FCR_IOSR_MASK GENMASK(7, 0) +#define DFSDM_FCR_IOSR(v) FIELD_PREP(DFSDM_FCR_IOSR_MASK, v) +#define DFSDM_FCR_FOSR_MASK GENMASK(25, 16) +#define DFSDM_FCR_FOSR(v) FIELD_PREP(DFSDM_FCR_FOSR_MASK, v) +#define DFSDM_FCR_FORD_MASK GENMASK(31, 29) +#define DFSDM_FCR_FORD(v) FIELD_PREP(DFSDM_FCR_FORD_MASK, v) + +/* RDATAR: Filter data register for regular channel */ +#define DFSDM_DATAR_CH_MASK GENMASK(2, 0) +#define DFSDM_DATAR_DATA_OFFSET 8 +#define DFSDM_DATAR_DATA_MASK GENMASK(31, DFSDM_DATAR_DATA_OFFSET) + +/* AWLTR: Filter analog watchdog low threshold register */ +#define DFSDM_AWLTR_BKAWL_MASK GENMASK(3, 0) +#define DFSDM_AWLTR_BKAWL(v) FIELD_PREP(DFSDM_AWLTR_BKAWL_MASK, v) +#define DFSDM_AWLTR_AWLT_MASK GENMASK(31, 8) +#define DFSDM_AWLTR_AWLT(v) FIELD_PREP(DFSDM_AWLTR_AWLT_MASK, v) + +/* AWHTR: Filter analog watchdog low threshold register */ +#define DFSDM_AWHTR_BKAWH_MASK GENMASK(3, 0) +#define DFSDM_AWHTR_BKAWH(v) FIELD_PREP(DFSDM_AWHTR_BKAWH_MASK, v) +#define DFSDM_AWHTR_AWHT_MASK GENMASK(31, 8) +#define DFSDM_AWHTR_AWHT(v) FIELD_PREP(DFSDM_AWHTR_AWHT_MASK, v) + +/* AWSR: Filter watchdog status register */ +#define DFSDM_AWSR_AWLTF_MASK GENMASK(7, 0) +#define DFSDM_AWSR_AWLTF(v) FIELD_PREP(DFSDM_AWSR_AWLTF_MASK, v) +#define DFSDM_AWSR_AWHTF_MASK GENMASK(15, 8) +#define DFSDM_AWSR_AWHTF(v) FIELD_PREP(DFSDM_AWSR_AWHTF_MASK, v) + +/* AWCFR: Filter watchdog status register */ +#define DFSDM_AWCFR_AWLTF_MASK GENMASK(7, 0) +#define DFSDM_AWCFR_AWLTF(v) FIELD_PREP(DFSDM_AWCFR_AWLTF_MASK, v) +#define DFSDM_AWCFR_AWHTF_MASK GENMASK(15, 8) +#define DFSDM_AWCFR_AWHTF(v) FIELD_PREP(DFSDM_AWCFR_AWHTF_MASK, v) + +/* DFSDM filter order */ +enum stm32_dfsdm_sinc_order { + DFSDM_FASTSINC_ORDER, /* FastSinc filter type */ + DFSDM_SINC1_ORDER, /* Sinc 1 filter type */ + DFSDM_SINC2_ORDER, /* Sinc 2 filter type */ + DFSDM_SINC3_ORDER, /* Sinc 3 filter type */ + DFSDM_SINC4_ORDER, /* Sinc 4 filter type (N.A. for watchdog) */ + DFSDM_SINC5_ORDER, /* Sinc 5 filter type (N.A. for watchdog) */ + DFSDM_NB_SINC_ORDER, +}; + +/** + * struct stm32_dfsdm_filter - structure relative to stm32 FDSDM filter + * @iosr: integrator oversampling + * @fosr: filter oversampling + * @ford: filter order + * @res: output sample resolution + * @sync_mode: filter synchronized with filter 0 + * @fast: filter fast mode + */ +struct stm32_dfsdm_filter { + unsigned int iosr; + unsigned int fosr; + enum stm32_dfsdm_sinc_order ford; + u64 res; + unsigned int sync_mode; + unsigned int fast; +}; + +/** + * struct stm32_dfsdm_channel - structure relative to stm32 FDSDM channel + * @id: id of the channel + * @type: interface type linked to stm32_dfsdm_chan_type + * @src: interface type linked to stm32_dfsdm_chan_src + * @alt_si: alternative serial input interface + */ +struct stm32_dfsdm_channel { + unsigned int id; + unsigned int type; + unsigned int src; + unsigned int alt_si; +}; + +/** + * struct stm32_dfsdm - stm32 FDSDM driver common data (for all instances) + * @base: control registers base cpu addr + * @phys_base: DFSDM IP register physical address + * @regmap: regmap for register read/write + * @fl_list: filter resources list + * @num_fls: number of filter resources available + * @ch_list: channel resources list + * @num_chs: number of channel resources available + * @spi_master_freq: SPI clock out frequency + */ +struct stm32_dfsdm { + void __iomem *base; + phys_addr_t phys_base; + struct regmap *regmap; + struct stm32_dfsdm_filter *fl_list; + unsigned int num_fls; + struct stm32_dfsdm_channel *ch_list; + unsigned int num_chs; + unsigned int spi_master_freq; +}; + +/* DFSDM channel serial spi clock source */ +enum stm32_dfsdm_spi_clk_src { + DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL, + DFSDM_CHANNEL_SPI_CLOCK_INTERNAL, + DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_FALLING, + DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_RISING +}; + +int stm32_dfsdm_start_dfsdm(struct stm32_dfsdm *dfsdm); +int stm32_dfsdm_stop_dfsdm(struct stm32_dfsdm *dfsdm); + +#endif
Add driver for stm32 DFSDM pheripheral. Its converts a sigma delta stream in n bit samples through a low pass filter and an integrator. stm32-dfsdm-core driver is the core part supporting the filter instances dedicated to sigma-delta ADC or audio PDM microphone purpose. Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@st.com> --- V3 -> V4 changes: - Patch is split into 2 parts, one dedicated to the core part, another dedicated to the ADC part. - Filter and channel functions migrated to ADC driver. drivers/iio/adc/Kconfig | 12 ++ drivers/iio/adc/Makefile | 1 + drivers/iio/adc/stm32-dfsdm-core.c | 318 ++++++++++++++++++++++++++++++++++++ drivers/iio/adc/stm32-dfsdm.h | 319 +++++++++++++++++++++++++++++++++++++ 4 files changed, 650 insertions(+) create mode 100644 drivers/iio/adc/stm32-dfsdm-core.c create mode 100644 drivers/iio/adc/stm32-dfsdm.h