staging: iio: adc: ad7606: Move out of staging

Move ad7606 ADC driver out of staging and into the mainline.

Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

6 files changed, 899 insertions, 0 deletions

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 7a3ca4ec0cb7..f3cc7a31bce5 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -69,6 +69,33 @@ config AD7476
 	  To compile this driver as a module, choose M here: the
 	  module will be called ad7476.
 
+config AD7606
+	tristate
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+
+config AD7606_IFACE_PARALLEL
+	tristate "Analog Devices AD7606 ADC driver with parallel interface support"
+	depends on HAS_IOMEM
+	select AD7606
+	help
+	  Say yes here to build parallel interface support for Analog Devices:
+	  ad7605-4, ad7606, ad7606-6, ad7606-4 analog to digital converters (ADC).
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad7606_parallel.
+
+config AD7606_IFACE_SPI
+	tristate "Analog Devices AD7606 ADC driver with spi interface support"
+	depends on SPI
+	select AD7606
+	help
+	  Say yes here to build spi interface support for Analog Devices:
+	  ad7605-4, ad7606, ad7606-6, ad7606-4 analog to digital converters (ADC).
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad7606_spi.
+
 config AD7766
 	tristate "Analog Devices AD7766/AD7767 ADC driver"
 	depends on SPI_MASTER
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 07df37f621bd..ea5031348052 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -11,6 +11,9 @@ obj-$(CONFIG_AD7291) += ad7291.o
 obj-$(CONFIG_AD7298) += ad7298.o
 obj-$(CONFIG_AD7923) += ad7923.o
 obj-$(CONFIG_AD7476) += ad7476.o
+obj-$(CONFIG_AD7606_IFACE_PARALLEL) += ad7606_par.o
+obj-$(CONFIG_AD7606_IFACE_SPI) += ad7606_spi.o
+obj-$(CONFIG_AD7606) += ad7606.o
 obj-$(CONFIG_AD7766) += ad7766.o
 obj-$(CONFIG_AD7791) += ad7791.o
 obj-$(CONFIG_AD7793) += ad7793.o
diff --git a/drivers/iio/adc/ad7606.c b/drivers/iio/adc/ad7606.c
new file mode 100644
index 000000000000..ebb8de03bbce
--- /dev/null
+++ b/drivers/iio/adc/ad7606.c
@@ -0,0 +1,583 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AD7606 SPI ADC driver
+ *
+ * Copyright 2011 Analog Devices Inc.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/util_macros.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+
+#include "ad7606.h"
+
+/*
+ * Scales are computed as 5000/32768 and 10000/32768 respectively,
+ * so that when applied to the raw values they provide mV values
+ */
+static const unsigned int scale_avail[2] = {
+	152588, 305176
+};
+
+static const unsigned int ad7606_oversampling_avail[7] = {
+	1, 2, 4, 8, 16, 32, 64,
+};
+
+static int ad7606_reset(struct ad7606_state *st)
+{
+	if (st->gpio_reset) {
+		gpiod_set_value(st->gpio_reset, 1);
+		ndelay(100); /* t_reset >= 100ns */
+		gpiod_set_value(st->gpio_reset, 0);
+		return 0;
+	}
+
+	return -ENODEV;
+}
+
+static int ad7606_read_samples(struct ad7606_state *st)
+{
+	unsigned int num = st->chip_info->num_channels;
+	u16 *data = st->data;
+	int ret;
+
+	/*
+	 * The frstdata signal is set to high while and after reading the sample
+	 * of the first channel and low for all other channels. This can be used
+	 * to check that the incoming data is correctly aligned. During normal
+	 * operation the data should never become unaligned, but some glitch or
+	 * electrostatic discharge might cause an extra read or clock cycle.
+	 * Monitoring the frstdata signal allows to recover from such failure
+	 * situations.
+	 */
+
+	if (st->gpio_frstdata) {
+		ret = st->bops->read_block(st->dev, 1, data);
+		if (ret)
+			return ret;
+
+		if (!gpiod_get_value(st->gpio_frstdata)) {
+			ad7606_reset(st);
+			return -EIO;
+		}
+
+		data++;
+		num--;
+	}
+
+	return st->bops->read_block(st->dev, num, data);
+}
+
+static irqreturn_t ad7606_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct ad7606_state *st = iio_priv(indio_dev);
+	int ret;
+
+	mutex_lock(&st->lock);
+
+	ret = ad7606_read_samples(st);
+	if (ret == 0)
+		iio_push_to_buffers_with_timestamp(indio_dev, st->data,
+						   iio_get_time_ns(indio_dev));
+
+	iio_trigger_notify_done(indio_dev->trig);
+	/* The rising edge of the CONVST signal starts a new conversion. */
+	gpiod_set_value(st->gpio_convst, 1);
+
+	mutex_unlock(&st->lock);
+
+	return IRQ_HANDLED;
+}
+
+static int ad7606_scan_direct(struct iio_dev *indio_dev, unsigned int ch)
+{
+	struct ad7606_state *st = iio_priv(indio_dev);
+	int ret;
+
+	gpiod_set_value(st->gpio_convst, 1);
+	ret = wait_for_completion_timeout(&st->completion,
+					  msecs_to_jiffies(1000));
+	if (!ret) {
+		ret = -ETIMEDOUT;
+		goto error_ret;
+	}
+
+	ret = ad7606_read_samples(st);
+	if (ret == 0)
+		ret = st->data[ch];
+
+error_ret:
+	gpiod_set_value(st->gpio_convst, 0);
+
+	return ret;
+}
+
+static int ad7606_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val,
+			   int *val2,
+			   long m)
+{
+	int ret;
+	struct ad7606_state *st = iio_priv(indio_dev);
+
+	switch (m) {
+	case IIO_CHAN_INFO_RAW:
+		ret = iio_device_claim_direct_mode(indio_dev);
+		if (ret)
+			return ret;
+
+		ret = ad7606_scan_direct(indio_dev, chan->address);
+		iio_device_release_direct_mode(indio_dev);
+
+		if (ret < 0)
+			return ret;
+		*val = (short)ret;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = 0;
+		*val2 = scale_avail[st->range];
+		return IIO_VAL_INT_PLUS_MICRO;
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		*val = st->oversampling;
+		return IIO_VAL_INT;
+	}
+	return -EINVAL;
+}
+
+static ssize_t in_voltage_scale_available_show(struct device *dev,
+					       struct device_attribute *attr,
+					       char *buf)
+{
+	int i, len = 0;
+
+	for (i = 0; i < ARRAY_SIZE(scale_avail); i++)
+		len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06u ",
+				 scale_avail[i]);
+
+	buf[len - 1] = '\n';
+
+	return len;
+}
+
+static IIO_DEVICE_ATTR_RO(in_voltage_scale_available, 0);
+
+static int ad7606_write_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int val,
+			    int val2,
+			    long mask)
+{
+	struct ad7606_state *st = iio_priv(indio_dev);
+	DECLARE_BITMAP(values, 3);
+	int i;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE:
+		mutex_lock(&st->lock);
+		i = find_closest(val2, scale_avail, ARRAY_SIZE(scale_avail));
+		gpiod_set_value(st->gpio_range, i);
+		st->range = i;
+		mutex_unlock(&st->lock);
+
+		return 0;
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		if (val2)
+			return -EINVAL;
+		i = find_closest(val, ad7606_oversampling_avail,
+				 ARRAY_SIZE(ad7606_oversampling_avail));
+
+		values[0] = i;
+
+		mutex_lock(&st->lock);
+		gpiod_set_array_value(ARRAY_SIZE(values), st->gpio_os->desc,
+				      st->gpio_os->info, values);
+		st->oversampling = ad7606_oversampling_avail[i];
+		mutex_unlock(&st->lock);
+
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static IIO_CONST_ATTR(oversampling_ratio_available, "1 2 4 8 16 32 64");
+
+static struct attribute *ad7606_attributes_os_and_range[] = {
+	&iio_dev_attr_in_voltage_scale_available.dev_attr.attr,
+	&iio_const_attr_oversampling_ratio_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group ad7606_attribute_group_os_and_range = {
+	.attrs = ad7606_attributes_os_and_range,
+};
+
+static struct attribute *ad7606_attributes_os[] = {
+	&iio_const_attr_oversampling_ratio_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group ad7606_attribute_group_os = {
+	.attrs = ad7606_attributes_os,
+};
+
+static struct attribute *ad7606_attributes_range[] = {
+	&iio_dev_attr_in_voltage_scale_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group ad7606_attribute_group_range = {
+	.attrs = ad7606_attributes_range,
+};
+
+#define AD760X_CHANNEL(num, mask) {				\
+		.type = IIO_VOLTAGE,				\
+		.indexed = 1,					\
+		.channel = num,					\
+		.address = num,					\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),\
+		.info_mask_shared_by_all = mask,		\
+		.scan_index = num,				\
+		.scan_type = {					\
+			.sign = 's',				\
+			.realbits = 16,				\
+			.storagebits = 16,			\
+			.endianness = IIO_CPU,			\
+		},						\
+}
+
+#define AD7605_CHANNEL(num)	\
+	AD760X_CHANNEL(num, 0)
+
+#define AD7606_CHANNEL(num)	\
+	AD760X_CHANNEL(num, BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO))
+
+static const struct iio_chan_spec ad7605_channels[] = {
+	IIO_CHAN_SOFT_TIMESTAMP(4),
+	AD7605_CHANNEL(0),
+	AD7605_CHANNEL(1),
+	AD7605_CHANNEL(2),
+	AD7605_CHANNEL(3),
+};
+
+static const struct iio_chan_spec ad7606_channels[] = {
+	IIO_CHAN_SOFT_TIMESTAMP(8),
+	AD7606_CHANNEL(0),
+	AD7606_CHANNEL(1),
+	AD7606_CHANNEL(2),
+	AD7606_CHANNEL(3),
+	AD7606_CHANNEL(4),
+	AD7606_CHANNEL(5),
+	AD7606_CHANNEL(6),
+	AD7606_CHANNEL(7),
+};
+
+static const struct ad7606_chip_info ad7606_chip_info_tbl[] = {
+	/* More devices added in future */
+	[ID_AD7605_4] = {
+		.channels = ad7605_channels,
+		.num_channels = 5,
+	},
+	[ID_AD7606_8] = {
+		.channels = ad7606_channels,
+		.num_channels = 9,
+		.has_oversampling = true,
+	},
+	[ID_AD7606_6] = {
+		.channels = ad7606_channels,
+		.num_channels = 7,
+		.has_oversampling = true,
+	},
+	[ID_AD7606_4] = {
+		.channels = ad7606_channels,
+		.num_channels = 5,
+		.has_oversampling = true,
+	},
+};
+
+static int ad7606_request_gpios(struct ad7606_state *st)
+{
+	struct device *dev = st->dev;
+
+	st->gpio_convst = devm_gpiod_get(dev, "adi,conversion-start",
+					 GPIOD_OUT_LOW);
+	if (IS_ERR(st->gpio_convst))
+		return PTR_ERR(st->gpio_convst);
+
+	st->gpio_reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(st->gpio_reset))
+		return PTR_ERR(st->gpio_reset);
+
+	st->gpio_range = devm_gpiod_get_optional(dev, "adi,range",
+						 GPIOD_OUT_LOW);
+	if (IS_ERR(st->gpio_range))
+		return PTR_ERR(st->gpio_range);
+
+	st->gpio_standby = devm_gpiod_get_optional(dev, "standby",
+						   GPIOD_OUT_HIGH);
+	if (IS_ERR(st->gpio_standby))
+		return PTR_ERR(st->gpio_standby);
+
+	st->gpio_frstdata = devm_gpiod_get_optional(dev, "adi,first-data",
+						    GPIOD_IN);
+	if (IS_ERR(st->gpio_frstdata))
+		return PTR_ERR(st->gpio_frstdata);
+
+	if (!st->chip_info->has_oversampling)
+		return 0;
+
+	st->gpio_os = devm_gpiod_get_array_optional(dev,
+						    "adi,oversampling-ratio",
+						    GPIOD_OUT_LOW);
+	return PTR_ERR_OR_ZERO(st->gpio_os);
+}
+
+/*
+ * The BUSY signal indicates when conversions are in progress, so when a rising
+ * edge of CONVST is applied, BUSY goes logic high and transitions low at the
+ * end of the entire conversion process. The falling edge of the BUSY signal
+ * triggers this interrupt.
+ */
+static irqreturn_t ad7606_interrupt(int irq, void *dev_id)
+{
+	struct iio_dev *indio_dev = dev_id;
+	struct ad7606_state *st = iio_priv(indio_dev);
+
+	if (iio_buffer_enabled(indio_dev)) {
+		gpiod_set_value(st->gpio_convst, 0);
+		iio_trigger_poll_chained(st->trig);
+	} else {
+		complete(&st->completion);
+	}
+
+	return IRQ_HANDLED;
+};
+
+static int ad7606_validate_trigger(struct iio_dev *indio_dev,
+				   struct iio_trigger *trig)
+{
+	struct ad7606_state *st = iio_priv(indio_dev);
+
+	if (st->trig != trig)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int ad7606_buffer_postenable(struct iio_dev *indio_dev)
+{
+	struct ad7606_state *st = iio_priv(indio_dev);
+
+	iio_triggered_buffer_postenable(indio_dev);
+	gpiod_set_value(st->gpio_convst, 1);
+
+	return 0;
+}
+
+static int ad7606_buffer_predisable(struct iio_dev *indio_dev)
+{
+	struct ad7606_state *st = iio_priv(indio_dev);
+
+	gpiod_set_value(st->gpio_convst, 0);
+
+	return iio_triggered_buffer_predisable(indio_dev);
+}
+
+static const struct iio_buffer_setup_ops ad7606_buffer_ops = {
+	.postenable = &ad7606_buffer_postenable,
+	.predisable = &ad7606_buffer_predisable,
+};
+
+static const struct iio_info ad7606_info_no_os_or_range = {
+	.read_raw = &ad7606_read_raw,
+	.validate_trigger = &ad7606_validate_trigger,
+};
+
+static const struct iio_info ad7606_info_os_and_range = {
+	.read_raw = &ad7606_read_raw,
+	.write_raw = &ad7606_write_raw,
+	.attrs = &ad7606_attribute_group_os_and_range,
+	.validate_trigger = &ad7606_validate_trigger,
+};
+
+static const struct iio_info ad7606_info_os = {
+	.read_raw = &ad7606_read_raw,
+	.write_raw = &ad7606_write_raw,
+	.attrs = &ad7606_attribute_group_os,
+	.validate_trigger = &ad7606_validate_trigger,
+};
+
+static const struct iio_info ad7606_info_range = {
+	.read_raw = &ad7606_read_raw,
+	.write_raw = &ad7606_write_raw,
+	.attrs = &ad7606_attribute_group_range,
+	.validate_trigger = &ad7606_validate_trigger,
+};
+
+static const struct iio_trigger_ops ad7606_trigger_ops = {
+	.validate_device = iio_trigger_validate_own_device,
+};
+
+static void ad7606_regulator_disable(void *data)
+{
+	struct ad7606_state *st = data;
+
+	regulator_disable(st->reg);
+}
+
+int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
+		 const char *name, unsigned int id,
+		 const struct ad7606_bus_ops *bops)
+{
+	struct ad7606_state *st;
+	int ret;
+	struct iio_dev *indio_dev;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+	dev_set_drvdata(dev, indio_dev);
+
+	st->dev = dev;
+	mutex_init(&st->lock);
+	st->bops = bops;
+	st->base_address = base_address;
+	/* tied to logic low, analog input range is +/- 5V */
+	st->range = 0;
+	st->oversampling = 1;
+
+	st->reg = devm_regulator_get(dev, "avcc");
+	if (IS_ERR(st->reg))
+		return PTR_ERR(st->reg);
+
+	ret = regulator_enable(st->reg);
+	if (ret) {
+		dev_err(dev, "Failed to enable specified AVcc supply\n");
+		return ret;
+	}
+
+	ret = devm_add_action_or_reset(dev, ad7606_regulator_disable, st);
+	if (ret)
+		return ret;
+
+	st->chip_info = &ad7606_chip_info_tbl[id];
+
+	ret = ad7606_request_gpios(st);
+	if (ret)
+		return ret;
+
+	indio_dev->dev.parent = dev;
+	if (st->gpio_os) {
+		if (st->gpio_range)
+			indio_dev->info = &ad7606_info_os_and_range;
+		else
+			indio_dev->info = &ad7606_info_os;
+	} else {
+		if (st->gpio_range)
+			indio_dev->info = &ad7606_info_range;
+		else
+			indio_dev->info = &ad7606_info_no_os_or_range;
+	}
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->name = name;
+	indio_dev->channels = st->chip_info->channels;
+	indio_dev->num_channels = st->chip_info->num_channels;
+
+	init_completion(&st->completion);
+
+	ret = ad7606_reset(st);
+	if (ret)
+		dev_warn(st->dev, "failed to RESET: no RESET GPIO specified\n");
+
+	st->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
+					  indio_dev->name, indio_dev->id);
+	if (!st->trig)
+		return -ENOMEM;
+
+	st->trig->ops = &ad7606_trigger_ops;
+	st->trig->dev.parent = dev;
+	iio_trigger_set_drvdata(st->trig, indio_dev);
+	ret = devm_iio_trigger_register(dev, st->trig);
+	if (ret)
+		return ret;
+
+	indio_dev->trig = iio_trigger_get(st->trig);
+
+	ret = devm_request_threaded_irq(dev, irq,
+					NULL,
+					&ad7606_interrupt,
+					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+					name, indio_dev);
+	if (ret)
+		return ret;
+
+	ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
+					      &iio_pollfunc_store_time,
+					      &ad7606_trigger_handler,
+					      &ad7606_buffer_ops);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+EXPORT_SYMBOL_GPL(ad7606_probe);
+
+#ifdef CONFIG_PM_SLEEP
+
+static int ad7606_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad7606_state *st = iio_priv(indio_dev);
+
+	if (st->gpio_standby) {
+		gpiod_set_value(st->gpio_range, 1);
+		gpiod_set_value(st->gpio_standby, 0);
+	}
+
+	return 0;
+}
+
+static int ad7606_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad7606_state *st = iio_priv(indio_dev);
+
+	if (st->gpio_standby) {
+		gpiod_set_value(st->gpio_range, st->range);
+		gpiod_set_value(st->gpio_standby, 1);
+		ad7606_reset(st);
+	}
+
+	return 0;
+}
+
+SIMPLE_DEV_PM_OPS(ad7606_pm_ops, ad7606_suspend, ad7606_resume);
+EXPORT_SYMBOL_GPL(ad7606_pm_ops);
+
+#endif
+
+MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/adc/ad7606.h b/drivers/iio/adc/ad7606.h
new file mode 100644
index 000000000000..5d12410f68e1
--- /dev/null
+++ b/drivers/iio/adc/ad7606.h
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * AD7606 ADC driver
+ *
+ * Copyright 2011 Analog Devices Inc.
+ */
+
+#ifndef IIO_ADC_AD7606_H_
+#define IIO_ADC_AD7606_H_
+
+/**
+ * struct ad7606_chip_info - chip specific information
+ * @channels:		channel specification
+ * @num_channels:	number of channels
+ * @has_oversampling:   whether the device has oversampling support
+ */
+struct ad7606_chip_info {
+	const struct iio_chan_spec	*channels;
+	unsigned int			num_channels;
+	bool				has_oversampling;
+};
+
+/**
+ * struct ad7606_state - driver instance specific data
+ * @dev		pointer to kernel device
+ * @chip_info		entry in the table of chips that describes this device
+ * @reg		regulator info for the the power supply of the device
+ * @bops		bus operations (SPI or parallel)
+ * @range		voltage range selection, selects which scale to apply
+ * @oversampling	oversampling selection
+ * @base_address	address from where to read data in parallel operation
+ * @lock		protect sensor state from concurrent accesses to GPIOs
+ * @gpio_convst	GPIO descriptor for conversion start signal (CONVST)
+ * @gpio_reset		GPIO descriptor for device hard-reset
+ * @gpio_range		GPIO descriptor for range selection
+ * @gpio_standby	GPIO descriptor for stand-by signal (STBY),
+ *			controls power-down mode of device
+ * @gpio_frstdata	GPIO descriptor for reading from device when data
+ *			is being read on the first channel
+ * @gpio_os		GPIO descriptors to control oversampling on the device
+ * @complete		completion to indicate end of conversion
+ * @trig		The IIO trigger associated with the device.
+ * @data		buffer for reading data from the device
+ */
+struct ad7606_state {
+	struct device			*dev;
+	const struct ad7606_chip_info	*chip_info;
+	struct regulator		*reg;
+	const struct ad7606_bus_ops	*bops;
+	unsigned int			range;
+	unsigned int			oversampling;
+	void __iomem			*base_address;
+
+	struct mutex			lock; /* protect sensor state */
+	struct gpio_desc		*gpio_convst;
+	struct gpio_desc		*gpio_reset;
+	struct gpio_desc		*gpio_range;
+	struct gpio_desc		*gpio_standby;
+	struct gpio_desc		*gpio_frstdata;
+	struct gpio_descs		*gpio_os;
+	struct iio_trigger		*trig;
+	struct completion		completion;
+
+	/*
+	 * DMA (thus cache coherency maintenance) requires the
+	 * transfer buffers to live in their own cache lines.
+	 * 8 * 16-bit samples + 64-bit timestamp
+	 */
+	unsigned short			data[12] ____cacheline_aligned;
+};
+
+/**
+ * struct ad7606_bus_ops - driver bus operations
+ * @read_block		function pointer for reading blocks of data
+ */
+struct ad7606_bus_ops {
+	/* more methods added in future? */
+	int (*read_block)(struct device *dev, int num, void *data);
+};
+
+int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
+		 const char *name, unsigned int id,
+		 const struct ad7606_bus_ops *bops);
+
+enum ad7606_supported_device_ids {
+	ID_AD7605_4,
+	ID_AD7606_8,
+	ID_AD7606_6,
+	ID_AD7606_4
+};
+
+#ifdef CONFIG_PM_SLEEP
+extern const struct dev_pm_ops ad7606_pm_ops;
+#define AD7606_PM_OPS (&ad7606_pm_ops)
+#else
+#define AD7606_PM_OPS NULL
+#endif
+
+#endif /* IIO_ADC_AD7606_H_ */
diff --git a/drivers/iio/adc/ad7606_par.c b/drivers/iio/adc/ad7606_par.c
new file mode 100644
index 000000000000..1b08028facde
--- /dev/null
+++ b/drivers/iio/adc/ad7606_par.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AD7606 Parallel Interface ADC driver
+ *
+ * Copyright 2011 Analog Devices Inc.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+#include <linux/err.h>
+#include <linux/io.h>
+
+#include <linux/iio/iio.h>
+#include "ad7606.h"
+
+static int ad7606_par16_read_block(struct device *dev,
+				   int count, void *buf)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad7606_state *st = iio_priv(indio_dev);
+
+	insw((unsigned long)st->base_address, buf, count);
+
+	return 0;
+}
+
+static const struct ad7606_bus_ops ad7606_par16_bops = {
+	.read_block = ad7606_par16_read_block,
+};
+
+static int ad7606_par8_read_block(struct device *dev,
+				  int count, void *buf)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad7606_state *st = iio_priv(indio_dev);
+
+	insb((unsigned long)st->base_address, buf, count * 2);
+
+	return 0;
+}
+
+static const struct ad7606_bus_ops ad7606_par8_bops = {
+	.read_block = ad7606_par8_read_block,
+};
+
+static int ad7606_par_probe(struct platform_device *pdev)
+{
+	const struct platform_device_id *id = platform_get_device_id(pdev);
+	struct resource *res;
+	void __iomem *addr;
+	resource_size_t remap_size;
+	int irq;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(&pdev->dev, "no irq: %d\n", irq);
+		return irq;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	addr = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(addr))
+		return PTR_ERR(addr);
+
+	remap_size = resource_size(res);
+
+	return ad7606_probe(&pdev->dev, irq, addr,
+			    id->name, id->driver_data,
+			    remap_size > 1 ? &ad7606_par16_bops :
+			    &ad7606_par8_bops);
+}
+
+static const struct platform_device_id ad7606_driver_ids[] = {
+	{ .name	= "ad7605-4", .driver_data = ID_AD7605_4, },
+	{ .name	= "ad7606-4", .driver_data = ID_AD7606_4, },
+	{ .name	= "ad7606-6", .driver_data = ID_AD7606_6, },
+	{ .name	= "ad7606-8", .driver_data = ID_AD7606_8, },
+	{ }
+};
+MODULE_DEVICE_TABLE(platform, ad7606_driver_ids);
+
+static const struct of_device_id ad7606_of_match[] = {
+	{ .compatible = "adi,ad7605-4" },
+	{ .compatible = "adi,ad7606-4" },
+	{ .compatible = "adi,ad7606-6" },
+	{ .compatible = "adi,ad7606-8" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, ad7606_of_match);
+
+static struct platform_driver ad7606_driver = {
+	.probe = ad7606_par_probe,
+	.id_table = ad7606_driver_ids,
+	.driver = {
+		.name = "ad7606",
+		.pm = AD7606_PM_OPS,
+		.of_match_table = ad7606_of_match,
+	},
+};
+module_platform_driver(ad7606_driver);
+
+MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/adc/ad7606_spi.c b/drivers/iio/adc/ad7606_spi.c
new file mode 100644
index 000000000000..4fd0ec36a086
--- /dev/null
+++ b/drivers/iio/adc/ad7606_spi.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AD7606 SPI ADC driver
+ *
+ * Copyright 2011 Analog Devices Inc.
+ */
+
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+#include <linux/types.h>
+#include <linux/err.h>
+
+#include <linux/iio/iio.h>
+#include "ad7606.h"
+
+#define MAX_SPI_FREQ_HZ		23500000	/* VDRIVE above 4.75 V */
+
+static int ad7606_spi_read_block(struct device *dev,
+				 int count, void *buf)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	int i, ret;
+	unsigned short *data = buf;
+	__be16 *bdata = buf;
+
+	ret = spi_read(spi, buf, count * 2);
+	if (ret < 0) {
+		dev_err(&spi->dev, "SPI read error\n");
+		return ret;
+	}
+
+	for (i = 0; i < count; i++)
+		data[i] = be16_to_cpu(bdata[i]);
+
+	return 0;
+}
+
+static const struct ad7606_bus_ops ad7606_spi_bops = {
+	.read_block = ad7606_spi_read_block,
+};
+
+static int ad7606_spi_probe(struct spi_device *spi)
+{
+	const struct spi_device_id *id = spi_get_device_id(spi);
+
+	return ad7606_probe(&spi->dev, spi->irq, NULL,
+			    id->name, id->driver_data,
+			    &ad7606_spi_bops);
+}
+
+static const struct spi_device_id ad7606_id_table[] = {
+	{ "ad7605-4", ID_AD7605_4 },
+	{ "ad7606-4", ID_AD7606_4 },
+	{ "ad7606-6", ID_AD7606_6 },
+	{ "ad7606-8", ID_AD7606_8 },
+	{}
+};
+MODULE_DEVICE_TABLE(spi, ad7606_id_table);
+
+static const struct of_device_id ad7606_of_match[] = {
+	{ .compatible = "adi,ad7605-4" },
+	{ .compatible = "adi,ad7606-4" },
+	{ .compatible = "adi,ad7606-6" },
+	{ .compatible = "adi,ad7606-8" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, ad7606_of_match);
+
+static struct spi_driver ad7606_driver = {
+	.driver = {
+		.name = "ad7606",
+		.of_match_table = ad7606_of_match,
+		.pm = AD7606_PM_OPS,
+	},
+	.probe = ad7606_spi_probe,
+	.id_table = ad7606_id_table,
+};
+module_spi_driver(ad7606_driver);
+
+MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
+MODULE_LICENSE("GPL v2");