[RFC v2 7/7] IIO: ADC: add stm32 DFSDM support
Arnaud Pouliquen
arnaud.pouliquen at st.com
Mon Feb 13 08:38:29 PST 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.
Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen at st.com>
---
drivers/iio/adc/Kconfig | 13 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/stm32-dfsdm-adc.c | 483 +++++++++++++++++++++++++++++++++++++
drivers/iio/adc/stm32-dfsdm-core.c | 273 +++++++++++++++++++++
drivers/iio/adc/stm32-dfsdm.h | 141 +++++++++++
5 files changed, 911 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 d4366ac..ab917b6 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -452,6 +452,19 @@ config STM32_ADC
This driver can also be built as a module. If so, the module
will be called stm32-adc.
+config STM32_DFSDM_ADC
+ tristate "STMicroelectronics STM32 dfsdm adc"
+ depends on (ARCH_STM32 && OF) || COMPILE_TEST
+ select REGMAP
+ select REGMAP_MMIO
+ select IIO_HW_CONSUMER
+ help
+ Select this option to enable the driver for STMicroelectronics
+ STM32 digital filter for sigma delta converter (ADC).
+
+ This driver can also be built as a module. If so, the module
+ will be called stm32-adc-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 bd67144..5bcad23 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -43,6 +43,7 @@ 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-$(CONFIG_STM32_DFSDM_ADC) += stm32-dfsdm-adc.o stm32-dfsdm-core.o
obj-$(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..8f9c3263
--- /dev/null
+++ b/drivers/iio/adc/stm32-dfsdm-adc.c
@@ -0,0 +1,483 @@
+/*
+ * This file is part of STM32 DFSDM ADC driver
+ *
+ * Copyright (C) 2016, 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/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include <linux/iio/hw_consumer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#include <sound/stm32-adfsdm.h>
+
+#include "stm32-dfsdm.h"
+
+enum stm32_dfsdm_mode {
+ DFSDM_ADC, /* ADC mode, access through IIO ABI */
+ DFSDM_AUDIO /* Audio mode, access through ASoC ABI */
+};
+
+struct stm32_dfsdm_adc {
+ struct stm32_dfsdm *common;
+
+ unsigned int fl_id;
+ unsigned int oversamp;
+ unsigned int clk_freq;
+
+ enum stm32_dfsdm_mode mode;
+ struct platform_device *audio_pdev;
+
+ void (*overrun_cb)(void *context);
+ void *cb_context;
+
+ /* Hardware consumer structure for Front End iio */
+ struct iio_hw_consumer *hwc;
+};
+
+static const enum stm32_dfsdm_mode stm32_dfsdm_data_adc = DFSDM_ADC;
+static const enum stm32_dfsdm_mode stm32_dfsdm_data_audio = DFSDM_AUDIO;
+
+struct stm32_dfsdm_adc_devdata {
+ enum stm32_dfsdm_mode mode;
+ const struct iio_info *info;
+};
+
+static int stm32_dfsdm_set_osrs(struct stm32_dfsdm_adc *adc, bool fast,
+ unsigned int oversamp)
+{
+ /*
+ * TODO
+ * This function tries to compute filter oversampling and integrator
+ * oversampling, base on oversampling ratio requested by user.
+ */
+
+ return 0;
+};
+
+static int stm32_dfsdm_single_conv(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan, int *res)
+{
+ /* TODO: Perform conversion instead of sending fake value */
+ dev_dbg(&indio_dev->dev, "%s\n", __func__);
+
+ *res = chan->channel + 0xFFFF00;
+ return 0;
+}
+
+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);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ ret = stm32_dfsdm_set_osrs(adc, 0, val);
+ if (!ret)
+ adc->oversamp = val;
+ break;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ if (adc->mode == DFSDM_AUDIO)
+ ret = stm32_dfsdm_set_osrs(adc, 0, val);
+ else
+ ret = -EINVAL;
+ break;
+
+ default:
+ ret = -EINVAL;
+ }
+
+ 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;
+
+ dev_dbg(&indio_dev->dev, "%s\n", __func__);
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ if (adc->hwc) {
+ 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;
+ }
+
+ if (adc->hwc)
+ iio_hw_consumer_disable(adc->hwc);
+
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ *val = adc->oversamp;
+
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *val = DIV_ROUND_CLOSEST(adc->clk_freq, 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 const struct iio_info stm32_dfsdm_info_audio = {
+ .read_raw = stm32_dfsdm_read_raw,
+ .write_raw = stm32_dfsdm_write_raw,
+ .driver_module = THIS_MODULE,
+};
+
+const struct stm32_dfsdm_adc_devdata stm32_dfsdm_devdata_adc = {
+ .mode = DFSDM_ADC,
+ .info = &stm32_dfsdm_info_adc,
+};
+
+const struct stm32_dfsdm_adc_devdata stm32_dfsdm_devdata_audio = {
+ .mode = DFSDM_AUDIO,
+ .info = &stm32_dfsdm_info_audio,
+};
+
+static irqreturn_t stm32_dfsdm_irq(int irq, void *arg)
+{
+ /* TODO */
+ return IRQ_HANDLED;
+}
+
+static void stm32_dfsdm_set_sysclk(struct stm32_dfsdm_adc *adc,
+ unsigned int freq)
+{
+ struct iio_dev *iio = iio_priv_to_dev(adc);
+
+ dev_dbg(&iio->dev, "%s:\n", __func__);
+
+ adc->clk_freq = freq;
+};
+
+ /* Set expected audio sampling rate */
+static int stm32_dfsdm_set_hwparam(struct stm32_dfsdm_adc *adc,
+ struct stm32_dfsdm_hw_param *params)
+{
+ struct iio_dev *iio = iio_priv_to_dev(adc);
+
+ dev_dbg(&iio->dev, "%s for rate %d\n", __func__, params->rate);
+
+ return stm32_dfsdm_set_osrs(adc, 0, params->rate);
+};
+
+ /* Called when ASoC starts an audio stream setup. */
+static int stm32_dfsdm_audio_startup(struct stm32_dfsdm_adc *adc)
+{
+ struct iio_dev *iio = iio_priv_to_dev(adc);
+
+ dev_dbg(&iio->dev, "%s\n", __func__);
+
+ return 0;
+};
+
+ /* Shuts down the audio stream. */
+static void stm32_dfsdm_audio_shutdown(struct stm32_dfsdm_adc *adc)
+{
+ struct iio_dev *iio = iio_priv_to_dev(adc);
+
+ dev_dbg(&iio->dev, "%s\n", __func__);
+};
+
+ /*
+ * Provides DMA source physicla addr to allow ALsa to handle DMA
+ * transfers.
+ */
+static dma_addr_t stm32_dfsdm_get_dma_source(struct stm32_dfsdm_adc *adc)
+{
+ struct iio_dev *iio = iio_priv_to_dev(adc);
+
+ dev_dbg(&iio->dev, "%s\n", __func__);
+
+ return (dma_addr_t)(adc->common->phys_base + DFSDM_RDATAR(adc->fl_id));
+};
+
+/* Register callback to treat underrun and overrun issues */
+static void stm32_dfsdm_register_xrun_cb(struct stm32_dfsdm_adc *adc,
+ void (*overrun_cb)(void *context),
+ void *context)
+{
+ struct iio_dev *iio = iio_priv_to_dev(adc);
+
+ dev_dbg(&iio->dev, "%s\n", __func__);
+ adc->overrun_cb = overrun_cb;
+ adc->cb_context = context;
+};
+
+const struct stm32_adfsdm_codec_ops stm32_dfsdm_audio_ops = {
+ .set_sysclk = stm32_dfsdm_set_sysclk,
+ .set_hwparam = stm32_dfsdm_set_hwparam,
+ .audio_startup = stm32_dfsdm_audio_startup,
+ .audio_shutdown = stm32_dfsdm_audio_shutdown,
+ .register_xrun_cb = stm32_dfsdm_register_xrun_cb,
+ .get_dma_source = stm32_dfsdm_get_dma_source
+};
+
+static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev,
+ struct iio_chan_spec *chan,
+ int chan_idx)
+{
+ struct iio_chan_spec *ch = &chan[chan_idx];
+ struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+ int ret;
+
+ dev_dbg(&indio_dev->dev, "%s:\n", __func__);
+ 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;
+ }
+
+ ch->type = IIO_VOLTAGE;
+ ch->indexed = 1;
+ ch->scan_index = chan_idx;
+ if (adc->mode == DFSDM_ADC) {
+ /*
+ * IIO_CHAN_INFO_RAW: used to compute regular conversion
+ * IIO_CHAN_INFO_SAMP_FREQ: used to indicate sampling frequency
+ * IIO_CHAN_INFO_OVERSAMPLING_RATIO: used set oversampling
+ */
+ ch->info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SAMP_FREQ) |
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO);
+ }
+
+ ch->scan_type.sign = 'u';
+ ch->scan_type.realbits = 24;
+ ch->scan_type.storagebits = 32;
+
+ return 0;
+}
+
+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->common->num_chs) {
+ dev_err(&indio_dev->dev, "Bad st,adc-channels?\n");
+ return num_ch < 0 ? num_ch : -EINVAL;
+ }
+
+ channels = devm_kcalloc(&indio_dev->dev, num_ch, sizeof(*channels),
+ GFP_KERNEL);
+ if (!channels)
+ return -ENOMEM;
+
+ if (adc->mode == DFSDM_ADC) {
+ /*
+ * Bind to sd modulator iio device for ADC only.
+ * For Audio the PDM microphone will be handled by ASoC
+ */
+ adc->hwc = iio_hw_consumer_alloc(&indio_dev->dev);
+ if (IS_ERR(adc->hwc)) {
+ dev_err(&indio_dev->dev, "no backend found\n");
+ return PTR_ERR(adc->hwc);
+ }
+ }
+
+ 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:
+ if (adc->hwc)
+ iio_hw_consumer_free(adc->hwc);
+ return ret;
+}
+
+static const struct of_device_id stm32_dfsdm_adc_match[] = {
+ { .compatible = "st,stm32-dfsdm-adc",
+ .data = &stm32_dfsdm_devdata_adc},
+ { .compatible = "st,stm32-dfsdm-pdm",
+ .data = &stm32_dfsdm_devdata_audio},
+ {}
+};
+
+static int stm32_dfsdm_adc_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct stm32_dfsdm_adc *adc;
+ const struct of_device_id *of_id;
+ struct device_node *np = dev->of_node;
+ const struct stm32_dfsdm_adc_devdata *devdata;
+ struct iio_dev *iio;
+ int ret, irq;
+
+ dev_dbg(dev, "%s:\n", __func__);
+
+ iio = devm_iio_device_alloc(dev, sizeof(*adc));
+ if (IS_ERR(iio)) {
+ dev_err(dev, "%s: failed to allocate iio", __func__);
+ return PTR_ERR(iio);
+ }
+
+ adc = iio_priv(iio);
+ if (IS_ERR(adc)) {
+ dev_err(dev, "%s: failed to allocate adc", __func__);
+ return PTR_ERR(adc);
+ }
+ adc->common = dev_get_drvdata(dev->parent);
+
+ /* Populate data structure depending on compatibility */
+ of_id = of_match_node(stm32_dfsdm_adc_match, np);
+ if (!of_id->data) {
+ dev_err(&pdev->dev, "Data associated to device is missing\n");
+ return -EINVAL;
+ }
+
+ devdata = (const struct stm32_dfsdm_adc_devdata *)of_id->data;
+ adc->mode = devdata->mode;
+
+ iio->name = np->name;
+ iio->dev.parent = dev;
+ iio->dev.of_node = np;
+ iio->info = devdata->info;
+ iio->modes = INDIO_DIRECT_MODE;
+
+ 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;
+ }
+
+ /*
+ * In a first step IRQs generated for channels are not treated.
+ * So IRQ associated to filter instance 0 is dedicated to the Filter 0.
+ * In a second step IRQ domain should be used for filter 0 when feature
+ * like Watchdog, clock absence detection,... will be integrated.
+ */
+ 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 = stm32_dfsdm_adc_chan_init(iio);
+ if (ret < 0)
+ return ret;
+
+ ret = iio_device_register(iio);
+ if (ret) {
+ dev_err(dev, "failed to register iio device\n");
+ return ret;
+ }
+
+ if (adc->mode == DFSDM_AUDIO) {
+ struct stm32_adfsdm_pdata dai_data = {
+ .ops = &stm32_dfsdm_audio_ops,
+ .adc = adc,
+ };
+
+ adc->audio_pdev = platform_device_register_data(
+ dev, STM32_ADFSDM_DRV_NAME,
+ PLATFORM_DEVID_AUTO,
+ &dai_data, sizeof(dai_data));
+
+ if (IS_ERR(adc->audio_pdev))
+ return PTR_ERR(adc->audio_pdev);
+ }
+
+ return 0;
+}
+
+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..195245d
--- /dev/null
+++ b/drivers/iio/adc/stm32-dfsdm-core.c
@@ -0,0 +1,273 @@
+/*
+ * This file is part of STM32 DFSDM mfd 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/mfd/core.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 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 - stm32 dfsdm private data
+ * @pdev: platform device
+ * @stm32_dfsdm: common data exported for all instances
+ * @regmap: register map of the device;
+ * @clkout_div: SPI clkout divider value.
+ * @n_active_ch: atomic active channel counter.
+ */
+struct dfsdm_priv {
+ struct platform_device *pdev;
+
+ struct stm32_dfsdm dfsdm;
+ struct regmap *regmap;
+
+ unsigned int clkout_div;
+ atomic_t n_active_ch;
+};
+
+/**
+ * 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);
+ int ret;
+ int div = priv->clkout_div;
+
+ if (atomic_inc_return(&priv->n_active_ch) == 1) {
+ /* TODO: enable clocks */
+
+ /* Output the SPI CLKOUT (if clkout_div == 0 clok if OFF) */
+ ret = regmap_update_bits(priv->regmap, DFSDM_CHCFGR1(0),
+ DFSDM_CHCFGR1_CKOUTDIV_MASK,
+ DFSDM_CHCFGR1_CKOUTDIV(div));
+ if (ret < 0)
+ return ret;
+
+ /* Global enable of DFSDM interface */
+ ret = regmap_update_bits(priv->regmap, DFSDM_CHCFGR1(0),
+ DFSDM_CHCFGR1_DFSDMEN_MASK,
+ DFSDM_CHCFGR1_DFSDMEN(1));
+ if (ret < 0)
+ return ret;
+ }
+
+ dev_dbg(&priv->pdev->dev, "%s: n_active_ch %d\n", __func__,
+ atomic_read(&priv->n_active_ch));
+
+ return 0;
+}
+
+/**
+ * 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(priv->regmap, DFSDM_CHCFGR1(0),
+ DFSDM_CHCFGR1_DFSDMEN_MASK,
+ DFSDM_CHCFGR1_DFSDMEN(0));
+ if (ret < 0)
+ return ret;
+
+ /* Stop SPI CLKOUT */
+ ret = regmap_update_bits(priv->regmap, DFSDM_CHCFGR1(0),
+ DFSDM_CHCFGR1_CKOUTDIV_MASK,
+ DFSDM_CHCFGR1_CKOUTDIV(0));
+ if (ret < 0)
+ return ret;
+
+ /* TODO: disable clocks */
+ }
+ dev_dbg(&priv->pdev->dev, "%s: n_active_ch %d\n", __func__,
+ atomic_read(&priv->n_active_ch));
+
+ 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;
+
+ 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);
+
+ 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_kzalloc(&pdev->dev, sizeof(*dfsdm->fl_list),
+ GFP_KERNEL);
+ if (!dfsdm->fl_list)
+ return -ENOMEM;
+
+ dfsdm->num_fls = dev_data->num_filters;
+ dfsdm->ch_list = devm_kzalloc(&pdev->dev, sizeof(*dfsdm->ch_list),
+ GFP_KERNEL);
+ if (!dfsdm->ch_list)
+ return -ENOMEM;
+ dfsdm->num_chs = dev_data->num_channels;
+ dev_err(&pdev->dev, "%s: dfsdm->num_ch: %d\n",
+ __func__, dfsdm->num_chs);
+
+ ret = stm32_dfsdm_parse_of(pdev, priv);
+ if (ret < 0)
+ return ret;
+
+ priv->regmap = devm_regmap_init_mmio(&pdev->dev, dfsdm->base,
+ &stm32h7_dfsdm_regmap_cfg);
+ if (IS_ERR(priv->regmap)) {
+ ret = PTR_ERR(priv->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);
+
+ 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..38ab15e
--- /dev/null
+++ b/drivers/iio/adc/stm32-dfsdm.h
@@ -0,0 +1,141 @@
+/*
+ * This file is part of STM32 DFSDM mfd 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>
+
+/*
+ * 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)
+
+/*
+ * 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)
+
+/**
+ * struct stm32_dfsdm_filter - structure relative to stm32 FDSDM filter
+ * TODO: complete structure.
+ * @id: filetr ID,
+ */
+struct stm32_dfsdm_filter {
+ unsigned int id;
+};
+
+/**
+ * struct stm32_dfsdm_channel - structure relative to stm32 FDSDM channel
+ * TODO: complete structure.
+ * @id: filetr ID,
+ */
+struct stm32_dfsdm_channel {
+ unsigned int id;
+};
+
+/**
+ * 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 stm32_dfsdm_filter *fl_list;
+ int num_fls;
+ struct stm32_dfsdm_channel *ch_list;
+ int num_chs;
+};
+
+int stm32_dfsdm_start_dfsdm(struct stm32_dfsdm *dfsdm);
+int stm32_dfsdm_stop_dfsdm(struct stm32_dfsdm *dfsdm);
+
+#endif
--
1.9.1
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