drivers/staging/iio/adc/ad7606.c - manifest_repos/valens - Git at Google

 /*
  * AD7606 SPI ADC driver
  *
  * Copyright 2011 Analog Devices Inc.
  *
  * Licensed under the GPL-2.
  */

 #include <linux/interrupt.h>
 #include <linux/device.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/sysfs.h>
 #include <linux/regulator/consumer.h>
 #include <linux/err.h>
 #include <linux/gpio/consumer.h>
 #include <linux/delay.h>
 #include <linux/sched.h>
 #include <linux/module.h>

 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 #include <linux/iio/buffer.h>
 #include <linux/iio/trigger_consumer.h>
 #include <linux/iio/triggered_buffer.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][2] = {
 	{0, 152588}, {0, 305176}
 };

 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 ad7606_state *st = iio_priv(pf->indio_dev);

 	gpiod_set_value(st->gpio_convst, 1);

 	return IRQ_HANDLED;
 }

 /**
  * ad7606_poll_bh_to_ring() bh of trigger launched polling to ring buffer
  * @work_s:	the work struct through which this was scheduled
  *
  * Currently there is no option in this driver to disable the saving of
  * timestamps within the ring.
  * I think the one copy of this at a time was to avoid problems if the
  * trigger was set far too high and the reads then locked up the computer.
  **/
 static void ad7606_poll_bh_to_ring(struct work_struct *work_s)
 {
 	struct ad7606_state *st = container_of(work_s, struct ad7606_state,
 						poll_work);
 	struct iio_dev *indio_dev = iio_priv_to_dev(st);
 	int ret;

 	ret = ad7606_read_samples(st);
 	if (ret == 0)
 		iio_push_to_buffers_with_timestamp(indio_dev, st->data,
 						   iio_get_time_ns(indio_dev));

 	gpiod_set_value(st->gpio_convst, 0);
 	iio_trigger_notify_done(indio_dev->trig);
 }

 static int ad7606_scan_direct(struct iio_dev *indio_dev, unsigned int ch)
 {
 	struct ad7606_state *st = iio_priv(indio_dev);
 	int ret;

 	st->done = false;
 	gpiod_set_value(st->gpio_convst, 1);

 	ret = wait_event_interruptible(st->wq_data_avail, st->done);
 	if (ret)
 		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 = scale_avail[st->range][0];
 		*val2 = scale_avail[st->range][1];
 		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, "%d.%06u ",
 				 scale_avail[i][0], scale_avail[i][1]);

 	buf[len - 1] = '\n';

 	return len;
 }

 static IIO_DEVICE_ATTR_RO(in_voltage_scale_available, 0);

 static int ad7606_oversampling_get_index(unsigned int val)
 {
 	unsigned char supported[] = {1, 2, 4, 8, 16, 32, 64};
 	int i;

 	for (i = 0; i < ARRAY_SIZE(supported); i++)
 		if (val == supported[i])
 			return i;

 	return -EINVAL;
 }

 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);
 	int values[3];
 	int ret, i;

 	switch (mask) {
 	case IIO_CHAN_INFO_SCALE:
 		ret = -EINVAL;
 		mutex_lock(&st->lock);
 		for (i = 0; i < ARRAY_SIZE(scale_avail); i++)
 			if (val2 == scale_avail[i][1]) {
 				gpiod_set_value(st->gpio_range, i);
 				st->range = i;

 				ret = 0;
 				break;
 			}
 		mutex_unlock(&st->lock);

 		return ret;
 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 		if (val2)
 			return -EINVAL;
 		ret = ad7606_oversampling_get_index(val);
 		if (ret < 0)
 			return ret;

 		values[0] = (ret >> 0) & 1;
 		values[1] = (ret >> 1) & 1;
 		values[2] = (ret >> 2) & 1;

 		mutex_lock(&st->lock);
 		gpiod_set_array_value(ARRAY_SIZE(values), st->gpio_os->desc,
 				      values);
 		st->oversampling = val;
 		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 AD7606_CHANNEL(num)					\
 	{							\
 		.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 =			\
 			BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
 		.scan_index = num,				\
 		.scan_type = {					\
 			.sign = 's',				\
 			.realbits = 16,				\
 			.storagebits = 16,			\
 			.endianness = IIO_CPU,			\
 		},						\
 	}

 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_AD7606_8] = {
 		.channels = ad7606_channels,
 		.num_channels = 9,
 	},
 	[ID_AD7606_6] = {
 		.channels = ad7606_channels,
 		.num_channels = 7,
 	},
 	[ID_AD7606_4] = {
 		.channels = ad7606_channels,
 		.num_channels = 5,
 	},
 };

 static int ad7606_request_gpios(struct ad7606_state *st)
 {
 	struct device *dev = st->dev;

 	st->gpio_convst = devm_gpiod_get(dev, "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, "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, "first-data",
 						    GPIOD_IN);
 	if (IS_ERR(st->gpio_frstdata))
 		return PTR_ERR(st->gpio_frstdata);

 	st->gpio_os = devm_gpiod_get_array_optional(dev, "oversampling-ratio",
 			GPIOD_OUT_LOW);
 	return PTR_ERR_OR_ZERO(st->gpio_os);
 }

 /**
  *  Interrupt handler
  */
 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)) {
 		schedule_work(&st->poll_work);
 	} else {
 		st->done = true;
 		wake_up_interruptible(&st->wq_data_avail);
 	}

 	return IRQ_HANDLED;
 };

 static const struct iio_info ad7606_info_no_os_or_range = {
 	.driver_module = THIS_MODULE,
 	.read_raw = &ad7606_read_raw,
 };

 static const struct iio_info ad7606_info_os_and_range = {
 	.driver_module = THIS_MODULE,
 	.read_raw = &ad7606_read_raw,
 	.write_raw = &ad7606_write_raw,
 	.attrs = &ad7606_attribute_group_os_and_range,
 };

 static const struct iio_info ad7606_info_os = {
 	.driver_module = THIS_MODULE,
 	.read_raw = &ad7606_read_raw,
 	.write_raw = &ad7606_write_raw,
 	.attrs = &ad7606_attribute_group_os,
 };

 static const struct iio_info ad7606_info_range = {
 	.driver_module = THIS_MODULE,
 	.read_raw = &ad7606_read_raw,
 	.write_raw = &ad7606_write_raw,
 	.attrs = &ad7606_attribute_group_range,
 };

 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);

 	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;
 	INIT_WORK(&st->poll_work, &ad7606_poll_bh_to_ring);

 	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 = ad7606_request_gpios(st);
 	if (ret)
 		goto error_disable_reg;

 	st->chip_info = &ad7606_chip_info_tbl[id];

 	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_waitqueue_head(&st->wq_data_avail);

 	ret = ad7606_reset(st);
 	if (ret)
 		dev_warn(st->dev, "failed to RESET: no RESET GPIO specified\n");

 	ret = request_irq(irq, ad7606_interrupt, IRQF_TRIGGER_FALLING, name,
 			  indio_dev);
 	if (ret)
 		goto error_disable_reg;

 	ret = iio_triggered_buffer_setup(indio_dev, &ad7606_trigger_handler,
 					 NULL, NULL);
 	if (ret)
 		goto error_free_irq;

 	ret = iio_device_register(indio_dev);
 	if (ret)
 		goto error_unregister_ring;

 	dev_set_drvdata(dev, indio_dev);

 	return 0;
 error_unregister_ring:
 	iio_triggered_buffer_cleanup(indio_dev);

 error_free_irq:
 	free_irq(irq, indio_dev);

 error_disable_reg:
 	regulator_disable(st->reg);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(ad7606_probe);

 int ad7606_remove(struct device *dev, int irq)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct ad7606_state *st = iio_priv(indio_dev);

 	iio_device_unregister(indio_dev);
 	iio_triggered_buffer_cleanup(indio_dev);

 	free_irq(irq, indio_dev);
 	regulator_disable(st->reg);

 	return 0;
 }
 EXPORT_SYMBOL_GPL(ad7606_remove);

 #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 <hennerich@blackfin.uclinux.org>");
 MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
 MODULE_LICENSE("GPL v2");
	/*
	* AD7606 SPI ADC driver
	*
	* Copyright 2011 Analog Devices Inc.
	*
	* Licensed under the GPL-2.
	*/

	#include <linux/interrupt.h>
	#include <linux/device.h>
	#include <linux/kernel.h>
	#include <linux/slab.h>
	#include <linux/sysfs.h>
	#include <linux/regulator/consumer.h>
	#include <linux/err.h>
	#include <linux/gpio/consumer.h>
	#include <linux/delay.h>
	#include <linux/sched.h>
	#include <linux/module.h>

	#include <linux/iio/iio.h>
	#include <linux/iio/sysfs.h>
	#include <linux/iio/buffer.h>
	#include <linux/iio/trigger_consumer.h>
	#include <linux/iio/triggered_buffer.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][2] = {
	{0, 152588}, {0, 305176}
	};

	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 ad7606_state *st = iio_priv(pf->indio_dev);

	gpiod_set_value(st->gpio_convst, 1);

	return IRQ_HANDLED;
	}

	/**
	* ad7606_poll_bh_to_ring() bh of trigger launched polling to ring buffer
	* @work_s: the work struct through which this was scheduled
	*
	* Currently there is no option in this driver to disable the saving of
	* timestamps within the ring.
	* I think the one copy of this at a time was to avoid problems if the
	* trigger was set far too high and the reads then locked up the computer.
	**/
	static void ad7606_poll_bh_to_ring(struct work_struct *work_s)
	{
	struct ad7606_state *st = container_of(work_s, struct ad7606_state,
	poll_work);
	struct iio_dev *indio_dev = iio_priv_to_dev(st);
	int ret;

	ret = ad7606_read_samples(st);
	if (ret == 0)
	iio_push_to_buffers_with_timestamp(indio_dev, st->data,
	iio_get_time_ns(indio_dev));

	gpiod_set_value(st->gpio_convst, 0);
	iio_trigger_notify_done(indio_dev->trig);
	}

	static int ad7606_scan_direct(struct iio_dev *indio_dev, unsigned int ch)
	{
	struct ad7606_state *st = iio_priv(indio_dev);
	int ret;

	st->done = false;
	gpiod_set_value(st->gpio_convst, 1);

	ret = wait_event_interruptible(st->wq_data_avail, st->done);
	if (ret)
	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 = scale_avail[st->range][0];
	*val2 = scale_avail[st->range][1];
	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, "%d.%06u ",
	scale_avail[i][0], scale_avail[i][1]);

	buf[len - 1] = '\n';

	return len;
	}

	static IIO_DEVICE_ATTR_RO(in_voltage_scale_available, 0);

	static int ad7606_oversampling_get_index(unsigned int val)
	{
	unsigned char supported[] = {1, 2, 4, 8, 16, 32, 64};
	int i;

	for (i = 0; i < ARRAY_SIZE(supported); i++)
	if (val == supported[i])
	return i;

	return -EINVAL;
	}

	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);
	int values[3];
	int ret, i;

	switch (mask) {
	case IIO_CHAN_INFO_SCALE:
	ret = -EINVAL;
	mutex_lock(&st->lock);
	for (i = 0; i < ARRAY_SIZE(scale_avail); i++)
	if (val2 == scale_avail[i][1]) {
	gpiod_set_value(st->gpio_range, i);
	st->range = i;

	ret = 0;
	break;
	}
	mutex_unlock(&st->lock);

	return ret;
	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
	if (val2)
	return -EINVAL;
	ret = ad7606_oversampling_get_index(val);
	if (ret < 0)
	return ret;

	values[0] = (ret >> 0) & 1;
	values[1] = (ret >> 1) & 1;
	values[2] = (ret >> 2) & 1;

	mutex_lock(&st->lock);
	gpiod_set_array_value(ARRAY_SIZE(values), st->gpio_os->desc,
	values);
	st->oversampling = val;
	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 AD7606_CHANNEL(num) \
	{ \
	.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 = \
	BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
	.scan_index = num, \
	.scan_type = { \
	.sign = 's', \
	.realbits = 16, \
	.storagebits = 16, \
	.endianness = IIO_CPU, \
	}, \
	}

	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_AD7606_8] = {
	.channels = ad7606_channels,
	.num_channels = 9,
	},
	[ID_AD7606_6] = {
	.channels = ad7606_channels,
	.num_channels = 7,
	},
	[ID_AD7606_4] = {
	.channels = ad7606_channels,
	.num_channels = 5,
	},
	};

	static int ad7606_request_gpios(struct ad7606_state *st)
	{
	struct device *dev = st->dev;

	st->gpio_convst = devm_gpiod_get(dev, "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, "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, "first-data",
	GPIOD_IN);
	if (IS_ERR(st->gpio_frstdata))
	return PTR_ERR(st->gpio_frstdata);

	st->gpio_os = devm_gpiod_get_array_optional(dev, "oversampling-ratio",
	GPIOD_OUT_LOW);
	return PTR_ERR_OR_ZERO(st->gpio_os);
	}

	/**
	* Interrupt handler
	*/
	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)) {
	schedule_work(&st->poll_work);
	} else {
	st->done = true;
	wake_up_interruptible(&st->wq_data_avail);
	}

	return IRQ_HANDLED;
	};

	static const struct iio_info ad7606_info_no_os_or_range = {
	.driver_module = THIS_MODULE,
	.read_raw = &ad7606_read_raw,
	};

	static const struct iio_info ad7606_info_os_and_range = {
	.driver_module = THIS_MODULE,
	.read_raw = &ad7606_read_raw,
	.write_raw = &ad7606_write_raw,
	.attrs = &ad7606_attribute_group_os_and_range,
	};

	static const struct iio_info ad7606_info_os = {
	.driver_module = THIS_MODULE,
	.read_raw = &ad7606_read_raw,
	.write_raw = &ad7606_write_raw,
	.attrs = &ad7606_attribute_group_os,
	};

	static const struct iio_info ad7606_info_range = {
	.driver_module = THIS_MODULE,
	.read_raw = &ad7606_read_raw,
	.write_raw = &ad7606_write_raw,
	.attrs = &ad7606_attribute_group_range,
	};

	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);

	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;
	INIT_WORK(&st->poll_work, &ad7606_poll_bh_to_ring);

	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 = ad7606_request_gpios(st);
	if (ret)
	goto error_disable_reg;

	st->chip_info = &ad7606_chip_info_tbl[id];

	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_waitqueue_head(&st->wq_data_avail);

	ret = ad7606_reset(st);
	if (ret)
	dev_warn(st->dev, "failed to RESET: no RESET GPIO specified\n");

	ret = request_irq(irq, ad7606_interrupt, IRQF_TRIGGER_FALLING, name,
	indio_dev);
	if (ret)
	goto error_disable_reg;

	ret = iio_triggered_buffer_setup(indio_dev, &ad7606_trigger_handler,
	NULL, NULL);
	if (ret)
	goto error_free_irq;

	ret = iio_device_register(indio_dev);
	if (ret)
	goto error_unregister_ring;

	dev_set_drvdata(dev, indio_dev);

	return 0;
	error_unregister_ring:
	iio_triggered_buffer_cleanup(indio_dev);

	error_free_irq:
	free_irq(irq, indio_dev);

	error_disable_reg:
	regulator_disable(st->reg);
	return ret;
	}
	EXPORT_SYMBOL_GPL(ad7606_probe);

	int ad7606_remove(struct device *dev, int irq)
	{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct ad7606_state *st = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);
	iio_triggered_buffer_cleanup(indio_dev);

	free_irq(irq, indio_dev);
	regulator_disable(st->reg);

	return 0;
	}
	EXPORT_SYMBOL_GPL(ad7606_remove);

	#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 <hennerich@blackfin.uclinux.org>");
	MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
	MODULE_LICENSE("GPL v2");