diff mbox series

[v5,1/3] iio: adc: add max11410 adc driver

Message ID 20220920152628.285-2-Ibrahim.Tilki@analog.com (mailing list archive)
State Changes Requested
Headers show
Series iio: adc: add max11410 adc driver | expand

Commit Message

Tilki, Ibrahim Sept. 20, 2022, 3:26 p.m. UTC
Adding support for max11410 24-bit, 1.9ksps delta-sigma adc which
has 3 differential reference and 10 differential channel inputs.
Inputs and references can be buffered internally. Inputs can also
be amplified with internal PGA.

Device has four digital filter modes: FIR50/60, FIR50, FIR60 and SINC4.
FIR 50Hz and 60Hz rejections can be enabled/disabled separately.
Digital filter selection affects sampling frequency range so driver
has to consider the configured filter when configuring sampling frequency.

Signed-off-by: Ibrahim Tilki <Ibrahim.Tilki@analog.com>
---
 drivers/iio/adc/Kconfig    |   13 +
 drivers/iio/adc/Makefile   |    1 +
 drivers/iio/adc/max11410.c | 1058 ++++++++++++++++++++++++++++++++++++
 3 files changed, 1072 insertions(+)
 create mode 100644 drivers/iio/adc/max11410.c

Comments

Jonathan Cameron Sept. 24, 2022, 2:11 p.m. UTC | #1
On Tue, 20 Sep 2022 18:26:26 +0300
Ibrahim Tilki <Ibrahim.Tilki@analog.com> wrote:

> Adding support for max11410 24-bit, 1.9ksps delta-sigma adc which
> has 3 differential reference and 10 differential channel inputs.
> Inputs and references can be buffered internally. Inputs can also
> be amplified with internal PGA.
> 
> Device has four digital filter modes: FIR50/60, FIR50, FIR60 and SINC4.
> FIR 50Hz and 60Hz rejections can be enabled/disabled separately.
> Digital filter selection affects sampling frequency range so driver
> has to consider the configured filter when configuring sampling frequency.
> 
> Signed-off-by: Ibrahim Tilki <Ibrahim.Tilki@analog.com>

Given we'll have a v6 to try and resolve the open question on the
binding, I may take another look, but on this look through
the driver looked very good to me, so no comments to address on this
patch or patch 3.

Jonathan
diff mbox series

Patch

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 56e3ca3b4a..40e34cde16 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -667,6 +667,19 @@  config MAX11205
 	  To compile this driver as a module, choose M here: the module will be
 	  called max11205.
 
+config MAX11410
+	tristate "Analog Devices MAX11410 ADC driver"
+	depends on SPI
+	select REGMAP_SPI
+	select IIO_BUFFER
+	select IIO_TRIGGER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say yes here to build support for Analog Devices MAX11410 ADCs.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called max11410.
+
 config MAX1241
 	tristate "Maxim max1241 ADC driver"
 	depends on SPI_MASTER
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 46caba7a01..4d80341342 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -62,6 +62,7 @@  obj-$(CONFIG_MAX1027) += max1027.o
 obj-$(CONFIG_MAX11100) += max11100.o
 obj-$(CONFIG_MAX1118) += max1118.o
 obj-$(CONFIG_MAX11205) += max11205.o
+obj-$(CONFIG_MAX11410) += max11410.o
 obj-$(CONFIG_MAX1241) += max1241.o
 obj-$(CONFIG_MAX1363) += max1363.o
 obj-$(CONFIG_MAX9611) += max9611.o
diff --git a/drivers/iio/adc/max11410.c b/drivers/iio/adc/max11410.c
new file mode 100644
index 0000000000..5194672906
--- /dev/null
+++ b/drivers/iio/adc/max11410.c
@@ -0,0 +1,1058 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * MAX11410 SPI ADC driver
+ *
+ * Copyright 2022 Analog Devices Inc.
+ */
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#define MAX11410_REG_CONV_START	0x01
+#define		MAX11410_CONV_TYPE_SINGLE	0x00
+#define		MAX11410_CONV_TYPE_CONTINUOUS	0x01
+#define MAX11410_REG_CAL_START	0x03
+#define		MAX11410_CAL_START_SELF		0x00
+#define		MAX11410_CAL_START_PGA		0x01
+#define MAX11410_REG_GPIO_CTRL(ch)		((ch) ? 0x05 : 0x04)
+#define		MAX11410_GPIO_INTRB		0xC1
+#define MAX11410_REG_FILTER	0x08
+#define		MAX11410_FILTER_RATE_MASK	GENMASK(3, 0)
+#define		MAX11410_FILTER_RATE_MAX	0x0F
+#define		MAX11410_FILTER_LINEF_MASK	GENMASK(5, 4)
+#define		MAX11410_FILTER_50HZ		BIT(5)
+#define		MAX11410_FILTER_60HZ		BIT(4)
+#define MAX11410_REG_CTRL	0x09
+#define		MAX11410_CTRL_REFSEL_MASK	GENMASK(2, 0)
+#define		MAX11410_CTRL_VREFN_BUF_BIT	BIT(3)
+#define		MAX11410_CTRL_VREFP_BUF_BIT	BIT(4)
+#define		MAX11410_CTRL_FORMAT_BIT	BIT(5)
+#define		MAX11410_CTRL_UNIPOLAR_BIT	BIT(6)
+#define MAX11410_REG_MUX_CTRL0	0x0B
+#define MAX11410_REG_PGA	0x0E
+#define		MAX11410_PGA_GAIN_MASK		GENMASK(2, 0)
+#define		MAX11410_PGA_SIG_PATH_MASK	GENMASK(5, 4)
+#define		MAX11410_PGA_SIG_PATH_BUFFERED	0x00
+#define		MAX11410_PGA_SIG_PATH_BYPASS	0x01
+#define		MAX11410_PGA_SIG_PATH_PGA	0x02
+#define MAX11410_REG_DATA0	0x30
+#define MAX11410_REG_STATUS	0x38
+#define		MAX11410_STATUS_CONV_READY_BIT	BIT(0)
+#define		MAX11410_STATUS_CAL_READY_BIT	BIT(2)
+
+#define MAX11410_REFSEL_AVDD_AGND	0x03
+#define MAX11410_REFSEL_MAX		0x06
+#define MAX11410_SIG_PATH_MAX		0x02
+#define MAX11410_CHANNEL_INDEX_MAX	0x0A
+#define MAX11410_AINP_AVDD	0x0A
+#define MAX11410_AINN_GND	0x0A
+
+#define MAX11410_CONVERSION_TIMEOUT_MS	2000
+#define MAX11410_CALIB_TIMEOUT_MS	2000
+
+#define MAX11410_SCALE_AVAIL_SIZE	8
+
+enum max11410_filter {
+	MAX11410_FILTER_FIR5060,
+	MAX11410_FILTER_FIR50,
+	MAX11410_FILTER_FIR60,
+	MAX11410_FILTER_SINC4,
+};
+
+static const u8 max11410_sampling_len[] = {
+	[MAX11410_FILTER_FIR5060] = 5,
+	[MAX11410_FILTER_FIR50] = 6,
+	[MAX11410_FILTER_FIR60] = 6,
+	[MAX11410_FILTER_SINC4] = 10,
+};
+
+static const int max11410_sampling_rates[4][10][2] = {
+	[MAX11410_FILTER_FIR5060] = {
+		{ 1, 100000 },
+		{ 2, 100000 },
+		{ 4, 200000 },
+		{ 8, 400000 },
+		{ 16, 800000 }
+	},
+	[MAX11410_FILTER_FIR50] = {
+		{ 1, 300000 },
+		{ 2, 700000 },
+		{ 5, 300000 },
+		{ 10, 700000 },
+		{ 21, 300000 },
+		{ 40 }
+	},
+	[MAX11410_FILTER_FIR60] = {
+		{ 1, 300000 },
+		{ 2, 700000 },
+		{ 5, 300000 },
+		{ 10, 700000 },
+		{ 21, 300000 },
+		{ 40 }
+	},
+	[MAX11410_FILTER_SINC4] = {
+		{ 4 },
+		{ 10 },
+		{ 20 },
+		{ 40 },
+		{ 60 },
+		{ 120 },
+		{ 240 },
+		{ 480 },
+		{ 960 },
+		{ 1920 }
+	}
+};
+
+struct max11410_channel_config {
+	u32 settling_time_us;
+	u32 *scale_avail;
+	u8 refsel;
+	u8 sig_path;
+	u8 gain;
+	bool bipolar;
+	bool buffered_vrefp;
+	bool buffered_vrefn;
+};
+
+struct max11410_state {
+	struct spi_device *spi_dev;
+	struct iio_trigger *trig;
+	struct completion completion;
+	struct mutex lock; /* Prevent changing channel config during sampling */
+	struct regmap *regmap;
+	struct regulator *avdd;
+	struct regulator *vrefp[3];
+	struct regulator *vrefn[3];
+	struct max11410_channel_config *channels;
+	int irq;
+	struct {
+		u32 data __aligned(IIO_DMA_MINALIGN);
+		s64 ts __aligned(8);
+	} scan;
+};
+
+static const struct iio_chan_spec chanspec_template = {
+	.type = IIO_VOLTAGE,
+	.indexed = 1,
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+			      BIT(IIO_CHAN_INFO_SCALE) |
+			      BIT(IIO_CHAN_INFO_OFFSET),
+	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+	.info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+	.scan_type = {
+		.sign = 's',
+		.realbits = 24,
+		.storagebits = 32,
+		.endianness = IIO_LE,
+	},
+};
+
+static unsigned int max11410_reg_size(unsigned int reg)
+{
+	/* Registers from 0x00 to 0x10 are 1 byte, the rest are 3 bytes long. */
+	return reg <= 0x10 ? 1 : 3;
+}
+
+static int max11410_write_reg(struct max11410_state *st, unsigned int reg,
+			      unsigned int val)
+{
+	/* This driver only needs to write 8-bit registers */
+	if (max11410_reg_size(reg) != 1)
+		return -EINVAL;
+
+	return regmap_write(st->regmap, reg, val);
+}
+
+static int max11410_read_reg(struct max11410_state *st, unsigned int reg,
+			     int *val)
+{
+	int ret;
+
+	if (max11410_reg_size(reg) == 3) {
+		ret = regmap_bulk_read(st->regmap, reg, &st->scan.data, 3);
+		if (ret)
+			return ret;
+
+		*val = get_unaligned_be24(&st->scan.data);
+		return 0;
+	}
+
+	return regmap_read(st->regmap, reg, val);
+}
+
+static struct regulator *max11410_get_vrefp(struct max11410_state *st,
+					    u8 refsel)
+{
+	refsel = refsel % 4;
+	if (refsel == 3)
+		return st->avdd;
+
+	return st->vrefp[refsel];
+}
+
+static struct regulator *max11410_get_vrefn(struct max11410_state *st,
+					    u8 refsel)
+{
+	if (refsel > 2)
+		return NULL;
+
+	return st->vrefn[refsel];
+}
+
+static const struct regmap_config regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0x39,
+};
+
+static ssize_t max11410_notch_en_show(struct device *dev,
+				      struct device_attribute *devattr,
+				      char *buf)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct max11410_state *state = iio_priv(indio_dev);
+	struct iio_dev_attr *iio_attr = to_iio_dev_attr(devattr);
+	unsigned int val;
+	int ret;
+
+	ret = max11410_read_reg(state, MAX11410_REG_FILTER, &val);
+	if (ret)
+		return ret;
+
+	switch (iio_attr->address) {
+	case 0:
+		val = !FIELD_GET(MAX11410_FILTER_50HZ, val);
+		break;
+	case 1:
+		val = !FIELD_GET(MAX11410_FILTER_60HZ, val);
+		break;
+	case 2:
+		val = FIELD_GET(MAX11410_FILTER_LINEF_MASK, val) == 3;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return sysfs_emit(buf, "%d\n", val);
+}
+
+static ssize_t max11410_notch_en_store(struct device *dev,
+				       struct device_attribute *devattr,
+				       const char *buf, size_t count)
+{
+	struct iio_dev_attr *iio_attr = to_iio_dev_attr(devattr);
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct max11410_state *state = iio_priv(indio_dev);
+	unsigned int filter_bits;
+	bool enable;
+	int ret;
+
+	ret = kstrtobool(buf, &enable);
+	if (ret)
+		return ret;
+
+	switch (iio_attr->address) {
+	case 0:
+		filter_bits = MAX11410_FILTER_50HZ;
+		break;
+	case 1:
+		filter_bits = MAX11410_FILTER_60HZ;
+		break;
+	case 2:
+	default:
+		filter_bits = MAX11410_FILTER_50HZ | MAX11410_FILTER_60HZ;
+		enable = !enable;
+		break;
+	}
+
+	if (enable)
+		ret = regmap_clear_bits(state->regmap, MAX11410_REG_FILTER,
+					filter_bits);
+	else
+		ret = regmap_set_bits(state->regmap, MAX11410_REG_FILTER,
+				      filter_bits);
+
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+static ssize_t in_voltage_filter2_notch_center_show(struct device *dev,
+						    struct device_attribute *devattr,
+						    char *buf)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct max11410_state *state = iio_priv(indio_dev);
+	int ret, reg, rate, filter;
+
+	ret = regmap_read(state->regmap, MAX11410_REG_FILTER, &reg);
+	if (ret)
+		return ret;
+
+	rate = FIELD_GET(MAX11410_FILTER_RATE_MASK, reg);
+	rate = clamp_val(rate, 0,
+			 max11410_sampling_len[MAX11410_FILTER_SINC4] - 1);
+	filter = max11410_sampling_rates[MAX11410_FILTER_SINC4][rate][0];
+
+	return sysfs_emit(buf, "%d\n", filter);
+}
+
+static IIO_CONST_ATTR(in_voltage_filter0_notch_center, "50");
+static IIO_CONST_ATTR(in_voltage_filter1_notch_center, "60");
+static IIO_DEVICE_ATTR_RO(in_voltage_filter2_notch_center, 2);
+
+static IIO_DEVICE_ATTR(in_voltage_filter0_notch_en, 0644,
+		       max11410_notch_en_show, max11410_notch_en_store, 0);
+static IIO_DEVICE_ATTR(in_voltage_filter1_notch_en, 0644,
+		       max11410_notch_en_show, max11410_notch_en_store, 1);
+static IIO_DEVICE_ATTR(in_voltage_filter2_notch_en, 0644,
+		       max11410_notch_en_show, max11410_notch_en_store, 2);
+
+static struct attribute *max11410_attributes[] = {
+	&iio_const_attr_in_voltage_filter0_notch_center.dev_attr.attr,
+	&iio_const_attr_in_voltage_filter1_notch_center.dev_attr.attr,
+	&iio_dev_attr_in_voltage_filter2_notch_center.dev_attr.attr,
+	&iio_dev_attr_in_voltage_filter0_notch_en.dev_attr.attr,
+	&iio_dev_attr_in_voltage_filter1_notch_en.dev_attr.attr,
+	&iio_dev_attr_in_voltage_filter2_notch_en.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group max11410_attribute_group = {
+	.attrs = max11410_attributes,
+};
+
+static int max11410_set_input_mux(struct max11410_state *st, u8 ainp, u8 ainn)
+{
+	if (ainp > MAX11410_CHANNEL_INDEX_MAX ||
+	    ainn > MAX11410_CHANNEL_INDEX_MAX)
+		return -EINVAL;
+
+	return max11410_write_reg(st, MAX11410_REG_MUX_CTRL0,
+				  (ainp << 4) | ainn);
+}
+
+static int max11410_configure_channel(struct max11410_state *st,
+				      struct iio_chan_spec const *chan)
+{
+	struct max11410_channel_config cfg = st->channels[chan->address];
+	unsigned int regval;
+	int ret;
+
+	if (chan->differential)
+		ret = max11410_set_input_mux(st, chan->channel, chan->channel2);
+	else
+		ret = max11410_set_input_mux(st, chan->channel,
+					     MAX11410_AINN_GND);
+
+	if (ret)
+		return ret;
+
+	regval = FIELD_PREP(MAX11410_CTRL_VREFP_BUF_BIT, cfg.buffered_vrefp) |
+		 FIELD_PREP(MAX11410_CTRL_VREFN_BUF_BIT, cfg.buffered_vrefn) |
+		 FIELD_PREP(MAX11410_CTRL_REFSEL_MASK, cfg.refsel) |
+		 FIELD_PREP(MAX11410_CTRL_UNIPOLAR_BIT, !cfg.bipolar);
+	ret = regmap_update_bits(st->regmap, MAX11410_REG_CTRL,
+				 MAX11410_CTRL_REFSEL_MASK |
+				 MAX11410_CTRL_VREFN_BUF_BIT |
+				 MAX11410_CTRL_VREFN_BUF_BIT |
+				 MAX11410_CTRL_UNIPOLAR_BIT, regval);
+	if (ret)
+		return ret;
+
+	regval = FIELD_PREP(MAX11410_PGA_SIG_PATH_MASK, cfg.sig_path) |
+		 FIELD_PREP(MAX11410_PGA_GAIN_MASK, cfg.gain);
+	ret = regmap_write(st->regmap, MAX11410_REG_PGA, regval);
+	if (ret)
+		return ret;
+
+	if (cfg.settling_time_us)
+		fsleep(cfg.settling_time_us);
+
+	return 0;
+}
+
+static int max11410_sample(struct max11410_state *st, int *sample_raw,
+			   struct iio_chan_spec const *chan)
+{
+	int val, ret;
+
+	ret = max11410_configure_channel(st, chan);
+	if (ret)
+		return ret;
+
+	if (st->irq > 0)
+		reinit_completion(&st->completion);
+
+	/* Start Conversion */
+	ret = max11410_write_reg(st, MAX11410_REG_CONV_START,
+				 MAX11410_CONV_TYPE_SINGLE);
+	if (ret)
+		return ret;
+
+	if (st->irq > 0) {
+		/* Wait for an interrupt. */
+		ret = wait_for_completion_timeout(&st->completion,
+						  msecs_to_jiffies(MAX11410_CONVERSION_TIMEOUT_MS));
+		if (!ret)
+			return -ETIMEDOUT;
+	} else {
+		/* Wait for status register Conversion Ready flag */
+		ret = read_poll_timeout(max11410_read_reg, ret,
+					ret || (val & MAX11410_STATUS_CONV_READY_BIT),
+					5000, MAX11410_CONVERSION_TIMEOUT_MS * 1000,
+					true, st, MAX11410_REG_STATUS, &val);
+		if (ret)
+			return ret;
+	}
+
+	/* Read ADC Data */
+	return max11410_read_reg(st, MAX11410_REG_DATA0, sample_raw);
+}
+
+static int max11410_get_scale(struct max11410_state *state,
+			      struct max11410_channel_config cfg)
+{
+	struct regulator *vrefp, *vrefn;
+	int scale;
+
+	vrefp = max11410_get_vrefp(state, cfg.refsel);
+
+	scale = regulator_get_voltage(vrefp) / 1000;
+	vrefn = max11410_get_vrefn(state, cfg.refsel);
+	if (vrefn)
+		scale -= regulator_get_voltage(vrefn) / 1000;
+
+	if (cfg.bipolar)
+		scale *= 2;
+
+	return scale >> cfg.gain;
+}
+
+static int max11410_read_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int *val, int *val2, long info)
+{
+	struct max11410_state *state = iio_priv(indio_dev);
+	struct max11410_channel_config cfg = state->channels[chan->address];
+	int ret, reg_val, filter, rate;
+
+	switch (info) {
+	case IIO_CHAN_INFO_SCALE:
+		*val = max11410_get_scale(state, cfg);
+		*val2 = chan->scan_type.realbits;
+		return IIO_VAL_FRACTIONAL_LOG2;
+	case IIO_CHAN_INFO_OFFSET:
+		if (cfg.bipolar)
+			*val = -BIT(chan->scan_type.realbits - 1);
+		else
+			*val = 0;
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_RAW:
+		ret = iio_device_claim_direct_mode(indio_dev);
+		if (ret)
+			return ret;
+
+		mutex_lock(&state->lock);
+
+		ret = max11410_sample(state, &reg_val, chan);
+
+		mutex_unlock(&state->lock);
+
+		iio_device_release_direct_mode(indio_dev);
+
+		if (ret)
+			return ret;
+
+		*val = reg_val;
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		ret = regmap_read(state->regmap, MAX11410_REG_FILTER, &reg_val);
+		if (ret)
+			return ret;
+
+		filter = FIELD_GET(MAX11410_FILTER_LINEF_MASK, reg_val);
+		rate = reg_val & MAX11410_FILTER_RATE_MASK;
+		if (rate >= max11410_sampling_len[filter])
+			rate = max11410_sampling_len[filter] - 1;
+
+		*val = max11410_sampling_rates[filter][rate][0];
+		*val2 = max11410_sampling_rates[filter][rate][1];
+
+		return IIO_VAL_INT_PLUS_MICRO;
+	}
+	return -EINVAL;
+}
+
+static int max11410_write_raw(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan,
+			      int val, int val2, long mask)
+{
+	struct max11410_state *st = iio_priv(indio_dev);
+	int i, ret, reg_val, filter, gain;
+	u32 *scale_avail;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE:
+		scale_avail = st->channels[chan->address].scale_avail;
+		if (!scale_avail)
+			return -EOPNOTSUPP;
+
+		/* Accept values in range 0.000001 <= scale < 1.000000 */
+		if (val != 0 || val2 == 0)
+			return -EINVAL;
+
+		ret = iio_device_claim_direct_mode(indio_dev);
+		if (ret)
+			return ret;
+
+		/* Convert from INT_PLUS_MICRO to FRACTIONAL_LOG2 */
+		val2 = val2 * DIV_ROUND_CLOSEST(BIT(24), 1000000);
+		val2 = DIV_ROUND_CLOSEST(scale_avail[0], val2);
+		gain = order_base_2(val2);
+
+		st->channels[chan->address].gain = clamp_val(gain, 0, 7);
+
+		iio_device_release_direct_mode(indio_dev);
+
+		return 0;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		ret = iio_device_claim_direct_mode(indio_dev);
+		if (ret)
+			return ret;
+
+		mutex_lock(&st->lock);
+
+		ret = regmap_read(st->regmap, MAX11410_REG_FILTER, &reg_val);
+		if (ret)
+			goto out;
+
+		filter = FIELD_GET(MAX11410_FILTER_LINEF_MASK, reg_val);
+
+		for (i = 0; i < max11410_sampling_len[filter]; ++i) {
+			if (val == max11410_sampling_rates[filter][i][0] &&
+			    val2 == max11410_sampling_rates[filter][i][1])
+				break;
+		}
+		if (i == max11410_sampling_len[filter]) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		ret = regmap_write_bits(st->regmap, MAX11410_REG_FILTER,
+					MAX11410_FILTER_RATE_MASK, i);
+
+out:
+		mutex_unlock(&st->lock);
+		iio_device_release_direct_mode(indio_dev);
+
+		return ret;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int max11410_read_avail(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *chan,
+			       const int **vals, int *type, int *length,
+			       long info)
+{
+	struct max11410_state *st = iio_priv(indio_dev);
+	struct max11410_channel_config cfg;
+	int ret, reg_val, filter;
+
+	switch (info) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		ret = regmap_read(st->regmap, MAX11410_REG_FILTER, &reg_val);
+		if (ret)
+			return ret;
+
+		filter = FIELD_GET(MAX11410_FILTER_LINEF_MASK, reg_val);
+
+		*vals = (const int *)max11410_sampling_rates[filter];
+		*length = max11410_sampling_len[filter] * 2;
+		*type = IIO_VAL_INT_PLUS_MICRO;
+
+		return IIO_AVAIL_LIST;
+	case IIO_CHAN_INFO_SCALE:
+		cfg = st->channels[chan->address];
+
+		if (!cfg.scale_avail)
+			return -EINVAL;
+
+		*vals = cfg.scale_avail;
+		*length = MAX11410_SCALE_AVAIL_SIZE * 2;
+		*type = IIO_VAL_FRACTIONAL_LOG2;
+
+		return IIO_AVAIL_LIST;
+	}
+	return -EINVAL;
+}
+
+static const struct iio_info max11410_info = {
+	.read_raw = max11410_read_raw,
+	.write_raw = max11410_write_raw,
+	.read_avail = max11410_read_avail,
+	.attrs = &max11410_attribute_group,
+};
+
+static irqreturn_t max11410_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct max11410_state *st = iio_priv(indio_dev);
+	int ret;
+
+	ret = max11410_read_reg(st, MAX11410_REG_DATA0, &st->scan.data);
+	if (ret) {
+		dev_err(&indio_dev->dev, "cannot read data\n");
+		goto out;
+	}
+
+	iio_push_to_buffers_with_timestamp(indio_dev, &st->scan,
+					   iio_get_time_ns(indio_dev));
+
+out:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int max11410_buffer_postenable(struct iio_dev *indio_dev)
+{
+	struct max11410_state *st = iio_priv(indio_dev);
+	int scan_ch, ret;
+
+	scan_ch = ffs(*indio_dev->active_scan_mask) - 1;
+
+	ret = max11410_configure_channel(st, &indio_dev->channels[scan_ch]);
+	if (ret)
+		return ret;
+
+	/* Start continuous conversion. */
+	return max11410_write_reg(st, MAX11410_REG_CONV_START,
+				  MAX11410_CONV_TYPE_CONTINUOUS);
+}
+
+static int max11410_buffer_predisable(struct iio_dev *indio_dev)
+{
+	struct max11410_state *st = iio_priv(indio_dev);
+
+	/* Stop continuous conversion. */
+	return max11410_write_reg(st, MAX11410_REG_CONV_START,
+				  MAX11410_CONV_TYPE_SINGLE);
+}
+
+static const struct iio_buffer_setup_ops max11410_buffer_ops = {
+	.postenable = &max11410_buffer_postenable,
+	.predisable = &max11410_buffer_predisable,
+	.validate_scan_mask = &iio_validate_scan_mask_onehot,
+};
+
+static const struct iio_trigger_ops max11410_trigger_ops = {
+	.validate_device = iio_trigger_validate_own_device,
+};
+
+static irqreturn_t max11410_interrupt(int irq, void *dev_id)
+{
+	struct iio_dev *indio_dev = dev_id;
+	struct max11410_state *st = iio_priv(indio_dev);
+
+	if (iio_buffer_enabled(indio_dev))
+		iio_trigger_poll_chained(st->trig);
+	else
+		complete(&st->completion);
+
+	return IRQ_HANDLED;
+};
+
+static int max11410_parse_channels(struct max11410_state *st,
+				   struct iio_dev *indio_dev)
+{
+	struct iio_chan_spec chanspec = chanspec_template;
+	struct device *dev = &st->spi_dev->dev;
+	struct max11410_channel_config *cfg;
+	struct iio_chan_spec *channels;
+	struct fwnode_handle *child;
+	u32 reference, sig_path;
+	const char *node_name;
+	u32 inputs[2], scale;
+	unsigned int num_ch;
+	int chan_idx = 0;
+	int ret, i;
+
+	num_ch = device_get_child_node_count(dev);
+	if (num_ch == 0)
+		return dev_err_probe(&indio_dev->dev, -ENODEV,
+				     "FW has no channels defined\n");
+
+	/* Reserve space for soft timestamp channel */
+	num_ch++;
+	channels = devm_kcalloc(dev, num_ch, sizeof(*channels), GFP_KERNEL);
+	if (!channels)
+		return -ENOMEM;
+
+	st->channels = devm_kcalloc(dev, num_ch, sizeof(*st->channels),
+				    GFP_KERNEL);
+	if (!st->channels)
+		return -ENOMEM;
+
+	device_for_each_child_node(dev, child) {
+		node_name = fwnode_get_name(child);
+		if (fwnode_property_present(child, "diff-channels")) {
+			ret = fwnode_property_read_u32_array(child,
+							     "diff-channels",
+							     inputs,
+							     ARRAY_SIZE(inputs));
+
+			chanspec.differential = 1;
+		} else {
+			ret = fwnode_property_read_u32(child, "reg", &inputs[0]);
+
+			inputs[1] = 0;
+			chanspec.differential = 0;
+		}
+		if (ret) {
+			fwnode_handle_put(child);
+			return ret;
+		}
+
+		if (inputs[0] > MAX11410_CHANNEL_INDEX_MAX ||
+		    inputs[1] > MAX11410_CHANNEL_INDEX_MAX) {
+			fwnode_handle_put(child);
+			return dev_err_probe(&indio_dev->dev, -EINVAL,
+					     "Invalid channel index for %s, should be less than %d\n",
+					     node_name,
+					     MAX11410_CHANNEL_INDEX_MAX + 1);
+		}
+
+		cfg = &st->channels[chan_idx];
+
+		reference = MAX11410_REFSEL_AVDD_AGND;
+		fwnode_property_read_u32(child, "adi,reference", &reference);
+		if (reference > MAX11410_REFSEL_MAX) {
+			fwnode_handle_put(child);
+			return dev_err_probe(&indio_dev->dev, -EINVAL,
+					     "Invalid adi,reference value for %s, should be less than %d.\n",
+					     node_name, MAX11410_REFSEL_MAX + 1);
+		}
+
+		if (!max11410_get_vrefp(st, reference) ||
+		    (!max11410_get_vrefn(st, reference) && reference <= 2)) {
+			fwnode_handle_put(child);
+			return dev_err_probe(&indio_dev->dev, -EINVAL,
+					     "Invalid VREF configuration for %s, either specify corresponding VREF regulators or change adi,reference property.\n",
+					     node_name);
+		}
+
+		sig_path = MAX11410_PGA_SIG_PATH_BUFFERED;
+		fwnode_property_read_u32(child, "adi,input-mode", &sig_path);
+		if (sig_path > MAX11410_SIG_PATH_MAX) {
+			fwnode_handle_put(child);
+			return dev_err_probe(&indio_dev->dev, -EINVAL,
+					     "Invalid adi,input-mode value for %s, should be less than %d.\n",
+					     node_name, MAX11410_SIG_PATH_MAX + 1);
+		}
+
+		fwnode_property_read_u32(child, "settling-time-us",
+					 &cfg->settling_time_us);
+		cfg->bipolar = fwnode_property_read_bool(child, "bipolar");
+		cfg->buffered_vrefp = fwnode_property_read_bool(child, "adi,buffered-vrefp");
+		cfg->buffered_vrefn = fwnode_property_read_bool(child, "adi,buffered-vrefn");
+		cfg->refsel = reference;
+		cfg->sig_path = sig_path;
+		cfg->gain = 0;
+
+		/* Enable scale_available property if input mode is PGA */
+		if (sig_path == MAX11410_PGA_SIG_PATH_PGA) {
+			__set_bit(IIO_CHAN_INFO_SCALE,
+				  &chanspec.info_mask_separate_available);
+			cfg->scale_avail = devm_kcalloc(dev, MAX11410_SCALE_AVAIL_SIZE * 2,
+							sizeof(*cfg->scale_avail),
+							GFP_KERNEL);
+			if (!cfg->scale_avail) {
+				fwnode_handle_put(child);
+				return -ENOMEM;
+			}
+
+			scale = max11410_get_scale(st, *cfg);
+			for (i = 0; i < MAX11410_SCALE_AVAIL_SIZE; i++) {
+				cfg->scale_avail[2 * i] = scale >> i;
+				cfg->scale_avail[2 * i + 1] = chanspec.scan_type.realbits;
+			}
+		} else {
+			__clear_bit(IIO_CHAN_INFO_SCALE,
+				    &chanspec.info_mask_separate_available);
+		}
+
+		chanspec.address = chan_idx;
+		chanspec.scan_index = chan_idx;
+		chanspec.channel = inputs[0];
+		chanspec.channel2 = inputs[1];
+
+		channels[chan_idx] = chanspec;
+		chan_idx++;
+	}
+
+	channels[chan_idx] = (struct iio_chan_spec)IIO_CHAN_SOFT_TIMESTAMP(chan_idx);
+
+	indio_dev->num_channels = chan_idx + 1;
+	indio_dev->channels = channels;
+
+	return 0;
+}
+
+static void max11410_disable_reg(void *reg)
+{
+	regulator_disable(reg);
+}
+
+static int max11410_init_vref(struct device *dev,
+			      struct regulator **vref,
+			      const char *id)
+{
+	struct regulator *reg;
+	int ret;
+
+	reg = devm_regulator_get_optional(dev, id);
+	if (PTR_ERR(reg) == -ENODEV) {
+		*vref = NULL;
+		return 0;
+	} else if (IS_ERR(reg)) {
+		return PTR_ERR(reg);
+	}
+	ret = regulator_enable(reg);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Failed to enable regulator %s\n", id);
+
+	*vref = reg;
+	return devm_add_action_or_reset(dev, max11410_disable_reg, reg);
+}
+
+static int max11410_calibrate(struct max11410_state *st, u32 cal_type)
+{
+	int ret, val;
+
+	ret = max11410_write_reg(st, MAX11410_REG_CAL_START, cal_type);
+	if (ret)
+		return ret;
+
+	/* Wait for status register Calibration Ready flag */
+	return read_poll_timeout(max11410_read_reg, ret,
+				 ret || (val & MAX11410_STATUS_CAL_READY_BIT),
+				 50000, MAX11410_CALIB_TIMEOUT_MS * 1000, true,
+				 st, MAX11410_REG_STATUS, &val);
+}
+
+static int max11410_self_calibrate(struct max11410_state *st)
+{
+	int ret, i;
+
+	ret = regmap_write_bits(st->regmap, MAX11410_REG_FILTER,
+				MAX11410_FILTER_RATE_MASK,
+				FIELD_PREP(MAX11410_FILTER_RATE_MASK,
+					   MAX11410_FILTER_RATE_MAX));
+	if (ret)
+		return ret;
+
+	ret = max11410_calibrate(st, MAX11410_CAL_START_SELF);
+	if (ret)
+		return ret;
+
+	ret = regmap_write_bits(st->regmap, MAX11410_REG_PGA,
+				MAX11410_PGA_SIG_PATH_MASK,
+				FIELD_PREP(MAX11410_PGA_SIG_PATH_MASK,
+					   MAX11410_PGA_SIG_PATH_PGA));
+	if (ret)
+		return ret;
+
+	/* PGA calibrations */
+	for (i = 1; i < 8; ++i) {
+		ret = regmap_write_bits(st->regmap, MAX11410_REG_PGA,
+					MAX11410_PGA_GAIN_MASK, i);
+		if (ret)
+			return ret;
+
+		ret = max11410_calibrate(st, MAX11410_CAL_START_PGA);
+		if (ret)
+			return ret;
+	}
+
+	/* Cleanup */
+	ret = regmap_write_bits(st->regmap, MAX11410_REG_PGA,
+				MAX11410_PGA_GAIN_MASK, 0);
+	if (ret)
+		return ret;
+
+	ret = regmap_write_bits(st->regmap, MAX11410_REG_FILTER,
+				MAX11410_FILTER_RATE_MASK, 0);
+	if (ret)
+		return ret;
+
+	return regmap_write_bits(st->regmap, MAX11410_REG_PGA,
+				 MAX11410_PGA_SIG_PATH_MASK,
+				 FIELD_PREP(MAX11410_PGA_SIG_PATH_MASK,
+					    MAX11410_PGA_SIG_PATH_BUFFERED));
+}
+
+static int max11410_probe(struct spi_device *spi)
+{
+	const char *vrefp_regs[] = { "vref0p", "vref1p", "vref2p" };
+	const char *vrefn_regs[] = { "vref0n", "vref1n", "vref2n" };
+	struct device *dev = &spi->dev;
+	struct max11410_state *st;
+	struct iio_dev *indio_dev;
+	int ret, irqs[2];
+	int i;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+	st->spi_dev = spi;
+	init_completion(&st->completion);
+	mutex_init(&st->lock);
+
+	indio_dev->name = "max11410";
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &max11410_info;
+
+	st->regmap = devm_regmap_init_spi(spi, &regmap_config);
+	if (IS_ERR(st->regmap))
+		return dev_err_probe(dev, PTR_ERR(st->regmap),
+				     "regmap initialization failed\n");
+
+	st->avdd = devm_regulator_get(dev, "avdd");
+	if (IS_ERR(st->avdd))
+		return dev_err_probe(dev, PTR_ERR(st->avdd),
+				     "avdd-supply is required.\n");
+
+	ret = regulator_enable(st->avdd);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(dev, max11410_disable_reg, st->avdd);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < ARRAY_SIZE(vrefp_regs); i++) {
+		ret = max11410_init_vref(dev, &st->vrefp[i], vrefp_regs[i]);
+		if (ret)
+			return ret;
+
+		ret = max11410_init_vref(dev, &st->vrefn[i], vrefn_regs[i]);
+		if (ret)
+			return ret;
+	}
+
+	/*
+	 * Regulators must be configured before parsing channels for
+	 * validating "adi,reference" property of each channel.
+	 */
+	ret = max11410_parse_channels(st, indio_dev);
+	if (ret)
+		return ret;
+
+	irqs[0] = fwnode_irq_get_byname(dev_fwnode(dev), "gpio0");
+	irqs[1] = fwnode_irq_get_byname(dev_fwnode(dev), "gpio1");
+
+	if (irqs[0] > 0) {
+		st->irq = irqs[0];
+		ret = regmap_write(st->regmap, MAX11410_REG_GPIO_CTRL(0),
+				   MAX11410_GPIO_INTRB);
+	} else if (irqs[1] > 0) {
+		st->irq = irqs[1];
+		ret = regmap_write(st->regmap, MAX11410_REG_GPIO_CTRL(1),
+				   MAX11410_GPIO_INTRB);
+	} else if (spi->irq > 0) {
+		return dev_err_probe(dev, -ENODEV,
+				     "no interrupt name specified");
+	}
+
+	if (ret)
+		return ret;
+
+	ret = regmap_set_bits(st->regmap, MAX11410_REG_CTRL,
+			      MAX11410_CTRL_FORMAT_BIT);
+	if (ret)
+		return ret;
+
+	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
+					      &max11410_trigger_handler,
+					      &max11410_buffer_ops);
+	if (ret)
+		return ret;
+
+	if (st->irq > 0) {
+		st->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
+						  indio_dev->name,
+						  iio_device_id(indio_dev));
+		if (!st->trig)
+			return -ENOMEM;
+
+		st->trig->ops = &max11410_trigger_ops;
+		ret = devm_iio_trigger_register(dev, st->trig);
+		if (ret)
+			return ret;
+
+		ret = devm_request_threaded_irq(dev, st->irq, NULL,
+						&max11410_interrupt,
+						IRQF_ONESHOT, "max11410",
+						indio_dev);
+		if (ret)
+			return ret;
+	}
+
+	ret = max11410_self_calibrate(st);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "cannot perform device self calibration\n");
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct of_device_id max11410_spi_of_id[] = {
+	{ .compatible = "adi,max11410" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, max11410_spi_of_id);
+
+static const struct spi_device_id max11410_id[] = {
+	{ "max11410" },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, max11410_id);
+
+static struct spi_driver max11410_driver = {
+	.driver = {
+		.name	= "max11410",
+		.of_match_table = max11410_spi_of_id,
+	},
+	.probe		= max11410_probe,
+	.id_table	= max11410_id,
+};
+module_spi_driver(max11410_driver);
+
+MODULE_AUTHOR("David Jung <David.Jung@analog.com>");
+MODULE_AUTHOR("Ibrahim Tilki <Ibrahim.Tilki@analog.com>");
+MODULE_DESCRIPTION("Analog Devices MAX11410 ADC");
+MODULE_LICENSE("GPL");