[PATCH v3 05/11] IIO: ADC: add stm32 DFSDM support for Sigma delta ADC
Arnaud Pouliquen
arnaud.pouliquen at st.com
Fri Mar 17 07:08:18 PDT 2017
Add driver for stm32 DFSDM IP. This IP converts a sigma delta stream
in n bit samples through a low pass filter and an integrator.
stm32-dfsdm-adc driver allows to handle sigma delta ADC.
Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen at st.com>
---
V2 -> V3 :
- Split audio and ADC support in 2 drivers
- Implement DMA cyclic mode
- Add SPI bus Trigger for buffer management
drivers/iio/adc/Kconfig | 26 ++
drivers/iio/adc/Makefile | 2 +
drivers/iio/adc/stm32-dfsdm-adc.c | 419 +++++++++++++++++++++++
drivers/iio/adc/stm32-dfsdm-core.c | 658 +++++++++++++++++++++++++++++++++++++
drivers/iio/adc/stm32-dfsdm.h | 372 +++++++++++++++++++++
5 files changed, 1477 insertions(+)
create mode 100644 drivers/iio/adc/stm32-dfsdm-adc.c
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 d411d66..3e0eb11 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -452,6 +452,32 @@ 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 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_DMAENGINE
+ select IIO_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 X86 && ISA_BUS_API
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index c68819c..161f271 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -43,6 +43,8 @@ obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
obj-$(CONFIG_STX104) += stx104.o
obj-$(CONFIG_STM32_ADC_CORE) += stm32-adc-core.o
obj-$(CONFIG_STM32_ADC) += stm32-adc.o
+obj-$(CONFIG_STM32_DFSDM_ADC) += stm32-dfsdm-adc.o
+obj-$(CONFIG_STM32_DFSDM_CORE) += stm32-dfsdm-core.o
obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o
obj-$(CONFIG_TI_ADC12138) += ti-adc12138.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..ebcb3b4
--- /dev/null
+++ b/drivers/iio/adc/stm32-dfsdm-adc.c
@@ -0,0 +1,419 @@
+/*
+ * This file is the ADC part of of the STM32 DFSDM driver
+ *
+ * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
+ * Author: Arnaud Pouliquen <arnaud.pouliquen at st.com>.
+ *
+ * License type: GPLv2
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#include <linux/iio/hw_consumer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#include "stm32-dfsdm.h"
+
+#define DFSDM_TIMEOUT_US 100000
+#define DFSDM_TIMEOUT (msecs_to_jiffies(DFSDM_TIMEOUT_US / 1000))
+
+struct stm32_dfsdm_adc {
+ struct stm32_dfsdm *dfsdm;
+ unsigned int fl_id;
+ unsigned int ch_id;
+
+ unsigned int oversamp;
+
+ struct completion completion;
+
+ u32 *buffer;
+
+ /* Hardware consumer structure for Front End IIO */
+ struct iio_hw_consumer *hwc;
+};
+
+static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc)
+{
+ int ret;
+
+ ret = stm32_dfsdm_start_dfsdm(adc->dfsdm);
+ if (ret < 0)
+ return ret;
+
+ ret = stm32_dfsdm_start_channel(adc->dfsdm, adc->ch_id);
+ if (ret < 0)
+ goto stop_dfsdm;
+
+ 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:
+ stm32_dfsdm_stop_channel(adc->dfsdm, adc->ch_id);
+stop_dfsdm:
+ stm32_dfsdm_stop_dfsdm(adc->dfsdm);
+
+ return ret;
+}
+
+static void stm32_dfsdm_stop_conv(struct stm32_dfsdm_adc *adc)
+{
+ stm32_dfsdm_stop_filter(adc->dfsdm, adc->fl_id);
+
+ stm32_dfsdm_stop_channel(adc->dfsdm, adc->ch_id);
+
+ stm32_dfsdm_stop_dfsdm(adc->dfsdm);
+}
+
+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;
+
+ /* Unmask IRQ for regular conversion achievement*/
+ ret = regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id),
+ DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(1));
+ if (ret < 0)
+ return ret;
+
+ ret = stm32_dfsdm_start_conv(adc);
+ if (ret < 0)
+ return ret;
+
+ 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) {
+ dev_warn(&indio_dev->dev, "Conversion timed out!\n");
+ ret = -ETIMEDOUT;
+ } else if (timeout < 0) {
+ ret = timeout;
+ } else {
+ dev_dbg(&indio_dev->dev, "Converted val %#x\n", *res);
+ ret = IIO_VAL_INT;
+ }
+
+ /* 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));
+
+ stm32_dfsdm_stop_conv(adc);
+
+ 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);
+ if (ret < 0) {
+ dev_err(&indio_dev->dev,
+ "%s: Conversion failed (channel %d)\n",
+ __func__, chan->channel);
+ return ret;
+ }
+
+ iio_hw_consumer_disable(adc->hwc);
+
+ 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,
+ .driver_module = THIS_MODULE,
+};
+
+static irqreturn_t stm32_dfsdm_irq(int irq, void *arg)
+{
+ struct stm32_dfsdm_adc *adc = arg;
+ struct regmap *regmap = adc->dfsdm->regmap;
+ unsigned int status;
+
+ regmap_read(regmap, DFSDM_ISR(adc->fl_id), &status);
+
+ 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) {
+ regmap_update_bits(regmap, DFSDM_ICR(adc->fl_id),
+ DFSDM_ICR_CLRROVRF_MASK,
+ DFSDM_ICR_CLRROVRF_MASK);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int stm32_dfsdm_postenable(struct iio_dev *indio_dev)
+{
+ struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+
+ return stm32_dfsdm_start_conv(adc);
+}
+
+static int stm32_dfsdm_predisable(struct iio_dev *indio_dev)
+{
+ struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+
+ stm32_dfsdm_stop_conv(adc);
+ return 0;
+}
+
+static const struct iio_buffer_setup_ops stm32_dfsdm_buffer_setup_ops = {
+ .postenable = &stm32_dfsdm_postenable,
+ .predisable = &stm32_dfsdm_predisable,
+};
+
+static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev,
+ struct iio_chan_spec *chan,
+ int ch_idx)
+{
+ struct iio_chan_spec *ch = &chan[ch_idx];
+ struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+ int ret;
+
+ ret = stm32_dfsdm_channel_parse_of(adc->dfsdm, indio_dev, chan, ch_idx);
+
+ ch->type = IIO_VOLTAGE;
+ ch->indexed = 1;
+ ch->scan_index = ch_idx;
+
+ /*
+ * 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) |
+ 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_chan_init(struct iio_dev *indio_dev)
+{
+ struct iio_chan_spec *channels;
+ struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+ unsigned int num_ch;
+ int ret, chan_idx;
+
+ 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;
+ }
+
+ /*
+ * Number of channel per filter is temporary limited to 1.
+ * Restriction should be cleaned with scan mode
+ */
+ if (num_ch > 1) {
+ dev_err(&indio_dev->dev, "Multi channel not yet supported\n");
+ return -EINVAL;
+ }
+
+ /* Bind to SD modulator IIO device */
+ adc->hwc = iio_hw_consumer_alloc(&indio_dev->dev);
+ if (IS_ERR(adc->hwc))
+ return -EPROBE_DEFER;
+
+ channels = devm_kcalloc(&indio_dev->dev, num_ch, sizeof(*channels),
+ GFP_KERNEL);
+ if (!channels)
+ return -ENOMEM;
+
+ for (chan_idx = 0; chan_idx < num_ch; chan_idx++) {
+ ret = stm32_dfsdm_adc_chan_init_one(indio_dev, channels,
+ chan_idx);
+ if (ret < 0)
+ goto free_hwc;
+ }
+
+ indio_dev->num_channels = num_ch;
+ indio_dev->channels = channels;
+
+ return 0;
+
+free_hwc:
+ iio_hw_consumer_free(adc->hwc);
+ return ret;
+}
+
+static const struct of_device_id stm32_dfsdm_adc_match[] = {
+ { .compatible = "st,stm32-dfsdm-adc"},
+ {}
+};
+
+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;
+ struct iio_dev *iio;
+ char *name;
+ int ret, irq, val;
+
+ 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->info = &stm32_dfsdm_info_adc;
+ 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 = kzalloc(sizeof("dfsdm-adc0"), GFP_KERNEL);
+ if (!name)
+ return -ENOMEM;
+ 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;
+
+ ret = stm32_dfsdm_adc_chan_init(iio);
+ if (ret < 0)
+ return ret;
+
+ init_completion(&adc->completion);
+
+ 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 *iio = iio_priv_to_dev(adc);
+
+ iio_device_unregister(iio);
+
+ 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 at st.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/adc/stm32-dfsdm-core.c b/drivers/iio/adc/stm32-dfsdm-core.c
new file mode 100644
index 0000000..488e456
--- /dev/null
+++ b/drivers/iio/adc/stm32-dfsdm-core.c
@@ -0,0 +1,658 @@
+/*
+ * This file is part the core part STM32 DFSDM driver
+ *
+ * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
+ * Author(s): Arnaud Pouliquen <arnaud.pouliquen at 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/interrupt.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#include <linux/iio/trigger.h>
+#include <linux/iio/sysfs.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
+
+#define DFSDM_MAX_INT_OVERSAMPLING 256
+
+#define DFSDM_MAX_FL_OVERSAMPLING 1024
+
+#define DFSDM_MAX_RES BIT(31)
+#define DFSDM_DATA_RES BIT(23)
+
+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 them
+ * 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 */
+
+ /* Clock */
+ struct clk *clk; /* DFSDM clock */
+ struct clk *aclk; /* audio clock */
+};
+
+/**
+ * stm32_dfsdm_set_osrs - compute filter parameters.
+ *
+ * Enable interface if n_active_ch is not null.
+ * @dfsdm: Handle used to retrieve dfsdm context.
+ * @fast: Fast mode enabled or disabled
+ * @oversamp: Expected oversampling between filtered sample and SD input stream
+ */
+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;
+ }
+
+ /*
+ * Looks for filter and integrator oversampling ratios which allows
+ * to reach 24 bits data output resolution.
+ * Leave at once 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;
+}
+
+/**
+ * stm32_dfsdm_start_dfsdm - start global dfsdm IP 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) {
+ /* Enable clocks */
+ ret = clk_prepare_enable(priv->clk);
+ if (ret < 0) {
+ dev_err(dev, "Failed to start clock\n");
+ return 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);
+
+ return ret;
+}
+
+/**
+ * stm32_dfsdm_stop_dfsdm - stop global DFSDM IP 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;
+
+ /* Disable clocks */
+ 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;
+}
+
+/**
+ * stm32_dfsdm_start_channel
+ * Start DFSDM IP channels and associated interface.
+ *
+ * @dfsdm: Handle used to retrieve dfsdm context.
+ * @ch_id: Channel index.
+ */
+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));
+}
+
+/**
+ * stm32_dfsdm_stop_channel
+ * Stop DFSDM IP channels and associated interface.
+ *
+ * @dfsdm: Handle used to retrieve dfsdm context.
+ * @ch_id: Channel index.
+ */
+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));
+}
+
+/**
+ * stm32_dfsdm_chan_configure
+ * Configure DFSDM IP channels and associated interface.
+ *
+ * @dfsdm: Handle used to retrieve dfsdm context.
+ * @ch_id: channel index.
+ */
+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));
+}
+
+/**
+ * stm32_dfsdm_start_filter - Start DFSDM IP filter conversion.
+ *
+ * @dfsdm: Handle used to retrieve dfsdm context.
+ * @fl_id: Filter index.
+ */
+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));
+}
+
+/**
+ * stm32_dfsdm_stop_filter - Stop DFSDM IP filter conversion.
+ *
+ * @dfsdm: Handle used to retrieve dfsdm context.
+ * @fl_id: Filter index.
+ */
+void stm32_dfsdm_stop_filter(struct stm32_dfsdm *dfsdm, unsigned int fl_id)
+{
+ /* Mask IRQ for regular conversion achievement*/
+ regmap_update_bits(dfsdm->regmap, DFSDM_CR2(fl_id),
+ DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(0));
+ /* Disable conversion */
+ regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id),
+ DFSDM_CR1_DFEN_MASK, DFSDM_CR1_DFEN(0));
+}
+
+/**
+ * stm32_dfsdm_filter_configure - Configure DFSDM IP filter and associate it
+ * to channel.
+ *
+ * @dfsdm: Handle used to retrieve dfsdm context.
+ * @fl_id: channel index.
+ * @fl_id: Filter index.
+ */
+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));
+
+ /* Filter order and Oversampling */
+ if (!ret)
+ ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id),
+ DFSDM_FCR_FOSR_MASK,
+ DFSDM_FCR_FOSR(fl->fosr));
+
+ if (!ret)
+ ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id),
+ DFSDM_FCR_FORD_MASK,
+ DFSDM_FCR_FORD(fl->ford));
+
+ /* If only one channel 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));
+
+ return regmap_update_bits(regmap, DFSDM_CR1(fl_id),
+ DFSDM_CR1_RSYNC_MASK,
+ DFSDM_CR1_RSYNC(fl->sync_mode));
+}
+
+static const struct iio_trigger_ops dfsdm_trigger_ops = {
+ .owner = THIS_MODULE,
+};
+
+static int stm32_dfsdm_setup_spi_trigger(struct platform_device *pdev,
+ struct stm32_dfsdm *dfsdm)
+{
+ /*
+ * To be able to use buffer consumer interface a trigger is needed.
+ * As conversion are trigged by PDM samples from SPI bus, that makes
+ * sense to define the serial interface ( SPI or manchester) as
+ * trigger source.
+ */
+
+ struct iio_trigger *trig;
+ int ret;
+
+ trig = devm_iio_trigger_alloc(&pdev->dev, DFSDM_SPI_TRIGGER_NAME);
+ if (!trig)
+ return -ENOMEM;
+
+ trig->dev.parent = pdev->dev.parent;
+ trig->ops = &dfsdm_trigger_ops;
+
+ iio_trigger_set_drvdata(trig, dfsdm);
+
+ ret = devm_iio_trigger_register(&pdev->dev, trig);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+int stm32_dfsdm_channel_parse_of(struct stm32_dfsdm *dfsdm,
+ struct iio_dev *indio_dev,
+ struct iio_chan_spec *chan, int chan_idx)
+{
+ struct iio_chan_spec *ch = &chan[chan_idx];
+ struct stm32_dfsdm_channel *df_ch;
+ const char *of_str;
+ 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;
+ }
+
+ 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);
+ val = stm32_dfsdm_str2val(of_str, stm32_dfsdm_chan_type);
+ if (ret < 0 || val < 0)
+ df_ch->type = 0;
+ else
+ df_ch->type = val;
+
+ ret = of_property_read_string_index(indio_dev->dev.of_node,
+ "st,adc-channel-clk-src", chan_idx,
+ &of_str);
+ val = stm32_dfsdm_str2val(of_str, stm32_dfsdm_chan_src);
+ if (ret < 0 || val < 0)
+ df_ch->src = 0;
+ else
+ 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_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;
+
+ /* Get resources */
+ 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);
+
+ /* Source clock */
+ 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 freq */
+ 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_remove(struct platform_device *pdev)
+{
+ of_platform_depopulate(&pdev->dev);
+
+ return 0;
+}
+
+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, i;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->pdev = pdev;
+
+ /* Populate data structure depending on compatibility */
+ 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;
+ }
+
+ for (i = 0; i < STM32H7_DFSDM_NUM_FILTERS; i++) {
+ struct stm32_dfsdm_filter *fl = &dfsdm->fl_list[i];
+
+ fl->id = i;
+ }
+
+ platform_set_drvdata(pdev, dfsdm);
+
+ ret = stm32_dfsdm_setup_spi_trigger(pdev, dfsdm);
+ if (ret < 0)
+ return ret;
+
+ return of_platform_populate(pnode, NULL, NULL, &pdev->dev);
+}
+
+static struct platform_driver stm32_dfsdm_driver = {
+ .probe = stm32_dfsdm_probe,
+ .remove = stm32_dfsdm_remove,
+ .driver = {
+ .name = "stm32-dfsdm",
+ .of_match_table = stm32_dfsdm_of_match,
+ },
+};
+
+module_platform_driver(stm32_dfsdm_driver);
+
+MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen at 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..bb7d74f
--- /dev/null
+++ b/drivers/iio/adc/stm32-dfsdm.h
@@ -0,0 +1,371 @@
+/*
+ * This file is part of STM32 DFSDM driver
+ *
+ * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
+ * Author(s): Arnaud Pouliquen <arnaud.pouliquen at 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>
+
+#include <linux/iio/iio.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
+ * TODO: complete structure.
+ * @id: filetr ID,
+ */
+struct stm32_dfsdm_filter {
+ unsigned int id;
+ unsigned int iosr; /* integrator oversampling */
+ unsigned int fosr; /* filter oversampling */
+ enum stm32_dfsdm_sinc_order ford;
+ u64 res; /* output sample resolution */
+ unsigned int sync_mode; /* filter suynchronized with filter0 */
+ unsigned int fast; /* filter fast mode */
+};
+
+/**
+ * struct stm32_dfsdm_channel - structure relative to stm32 FDSDM channel
+ * TODO: complete structure.
+ * @id: filetr ID,
+ */
+struct stm32_dfsdm_channel {
+ unsigned int id; /* id of the channel */
+ unsigned int type; /* interface type linked to stm32_dfsdm_chan_type */
+ unsigned int src; /* interface type linked to stm32_dfsdm_chan_src */
+ unsigned int alt_si; /* use alternative serial input interface */
+};
+
+/**
+ * struct stm32_dfsdm - stm32 FDSDM driver common data (for all instances)
+ * @base: control registers base cpu addr
+ * @phys_base: DFSDM IP register physical address.
+ * @fl_list: filter resources list
+ * @num_fl: number of filter resources available
+ * @ch_list: channel resources list
+ * @num_chs: number of channel resources available
+ */
+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;
+};
+
+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 */
+ { 0, 0},
+};
+
+/* 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
+};
+
+/* 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 },
+ { 0, 0 },
+};
+
+/* DFSDM Serial interface trigger name */
+#define DFSDM_SPI_TRIGGER_NAME "DFSDM_SERIAL_IN"
+
+static inline 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;
+}
+
+int stm32_dfsdm_set_osrs(struct stm32_dfsdm_filter *fl, unsigned int fast,
+ unsigned int oversamp);
+int stm32_dfsdm_start_dfsdm(struct stm32_dfsdm *dfsdm);
+int stm32_dfsdm_stop_dfsdm(struct stm32_dfsdm *dfsdm);
+
+int stm32_dfsdm_filter_configure(struct stm32_dfsdm *dfsdm, unsigned int fl_id,
+ unsigned int ch_id);
+int stm32_dfsdm_start_filter(struct stm32_dfsdm *dfsdm, unsigned int fl_id);
+void stm32_dfsdm_stop_filter(struct stm32_dfsdm *dfsdm, unsigned int fl_id);
+
+int stm32_dfsdm_chan_configure(struct stm32_dfsdm *dfsdm,
+ struct stm32_dfsdm_channel *ch);
+int stm32_dfsdm_start_channel(struct stm32_dfsdm *dfsdm, unsigned int ch_id);
+void stm32_dfsdm_stop_channel(struct stm32_dfsdm *dfsdm, unsigned int ch_id);
+
+int stm32_dfsdm_channel_parse_of(struct stm32_dfsdm *dfsdm,
+ struct iio_dev *indio_dev,
+ struct iio_chan_spec *chan, int chan_idx);
+
+#endif
--
1.9.1
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