drivers/iio/adc/ad799x.c - kernel/msm-4.9 - Gitiles

 /*
  * iio/adc/ad799x.c
  * Copyright (C) 2010-2011 Michael Hennerich, Analog Devices Inc.
  *
  * based on iio/adc/max1363
  * Copyright (C) 2008-2010 Jonathan Cameron
  *
  * based on linux/drivers/i2c/chips/max123x
  * Copyright (C) 2002-2004 Stefan Eletzhofer
  *
  * based on linux/drivers/acron/char/pcf8583.c
  * Copyright (C) 2000 Russell King
  *
  * 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.
  *
  * ad799x.c
  *
  * Support for ad7991, ad7995, ad7999, ad7992, ad7993, ad7994, ad7997,
  * ad7998 and similar chips.
  *
  */

 #include <linux/interrupt.h>
 #include <linux/device.h>
 #include <linux/kernel.h>
 #include <linux/sysfs.h>
 #include <linux/i2c.h>
 #include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/bitops.h>

 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 #include <linux/iio/events.h>
 #include <linux/iio/buffer.h>
 #include <linux/iio/trigger_consumer.h>
 #include <linux/iio/triggered_buffer.h>

 #define AD799X_CHANNEL_SHIFT			4

 /*
  * AD7991, AD7995 and AD7999 defines
  */

 #define AD7991_REF_SEL				0x08
 #define AD7991_FLTR				0x04
 #define AD7991_BIT_TRIAL_DELAY			0x02
 #define AD7991_SAMPLE_DELAY			0x01

 /*
  * AD7992, AD7993, AD7994, AD7997 and AD7998 defines
  */

 #define AD7998_FLTR				BIT(3)
 #define AD7998_ALERT_EN				BIT(2)
 #define AD7998_BUSY_ALERT			BIT(1)
 #define AD7998_BUSY_ALERT_POL			BIT(0)

 #define AD7998_CONV_RES_REG			0x0
 #define AD7998_ALERT_STAT_REG			0x1
 #define AD7998_CONF_REG				0x2
 #define AD7998_CYCLE_TMR_REG			0x3

 #define AD7998_DATALOW_REG(x)			((x) * 3 + 0x4)
 #define AD7998_DATAHIGH_REG(x)			((x) * 3 + 0x5)
 #define AD7998_HYST_REG(x)			((x) * 3 + 0x6)

 #define AD7998_CYC_MASK				GENMASK(2, 0)
 #define AD7998_CYC_DIS				0x0
 #define AD7998_CYC_TCONF_32			0x1
 #define AD7998_CYC_TCONF_64			0x2
 #define AD7998_CYC_TCONF_128			0x3
 #define AD7998_CYC_TCONF_256			0x4
 #define AD7998_CYC_TCONF_512			0x5
 #define AD7998_CYC_TCONF_1024			0x6
 #define AD7998_CYC_TCONF_2048			0x7

 #define AD7998_ALERT_STAT_CLEAR			0xFF

 /*
  * AD7997 and AD7997 defines
  */

 #define AD7997_8_READ_SINGLE			BIT(7)
 #define AD7997_8_READ_SEQUENCE			(BIT(6) | BIT(5) | BIT(4))

 enum {
 	ad7991,
 	ad7995,
 	ad7999,
 	ad7992,
 	ad7993,
 	ad7994,
 	ad7997,
 	ad7998
 };

 /**
  * struct ad799x_chip_config - chip specific information
  * @channel:		channel specification
  * @default_config:	device default configuration
  * @info:		pointer to iio_info struct
  */
 struct ad799x_chip_config {
 	const struct iio_chan_spec	channel[9];
 	u16				default_config;
 	const struct iio_info		*info;
 };

 /**
  * struct ad799x_chip_info - chip specific information
  * @num_channels:	number of channels
  * @noirq_config:	device configuration w/o IRQ
  * @irq_config:		device configuration w/IRQ
  */
 struct ad799x_chip_info {
 	int				num_channels;
 	const struct ad799x_chip_config	noirq_config;
 	const struct ad799x_chip_config	irq_config;
 };

 struct ad799x_state {
 	struct i2c_client		*client;
 	const struct ad799x_chip_config	*chip_config;
 	struct regulator		*reg;
 	struct regulator		*vref;
 	unsigned			id;
 	u16				config;

 	u8				*rx_buf;
 	unsigned int			transfer_size;
 };

 static int ad799x_write_config(struct ad799x_state *st, u16 val)
 {
 	switch (st->id) {
 	case ad7997:
 	case ad7998:
 		return i2c_smbus_write_word_swapped(st->client, AD7998_CONF_REG,
 			val);
 	case ad7992:
 	case ad7993:
 	case ad7994:
 		return i2c_smbus_write_byte_data(st->client, AD7998_CONF_REG,
 			val);
 	default:
 		/* Will be written when doing a conversion */
 		st->config = val;
 		return 0;
 	}
 }

 static int ad799x_read_config(struct ad799x_state *st)
 {
 	switch (st->id) {
 	case ad7997:
 	case ad7998:
 		return i2c_smbus_read_word_swapped(st->client, AD7998_CONF_REG);
 	case ad7992:
 	case ad7993:
 	case ad7994:
 		return i2c_smbus_read_byte_data(st->client, AD7998_CONF_REG);
 	default:
 		/* No readback support */
 		return st->config;
 	}
 }

 /**
  * ad799x_trigger_handler() bh of trigger launched polling to ring buffer
  *
  * Currently there is no option in this driver to disable the saving of
  * timestamps within the ring.
  **/
 static irqreturn_t ad799x_trigger_handler(int irq, void *p)
 {
 	struct iio_poll_func *pf = p;
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct ad799x_state *st = iio_priv(indio_dev);
 	int b_sent;
 	u8 cmd;

 	switch (st->id) {
 	case ad7991:
 	case ad7995:
 	case ad7999:
 		cmd = st->config |
 			(*indio_dev->active_scan_mask << AD799X_CHANNEL_SHIFT);
 		break;
 	case ad7992:
 	case ad7993:
 	case ad7994:
 		cmd = (*indio_dev->active_scan_mask << AD799X_CHANNEL_SHIFT) |
 			AD7998_CONV_RES_REG;
 		break;
 	case ad7997:
 	case ad7998:
 		cmd = AD7997_8_READ_SEQUENCE | AD7998_CONV_RES_REG;
 		break;
 	default:
 		cmd = 0;
 	}

 	b_sent = i2c_smbus_read_i2c_block_data(st->client,
 			cmd, st->transfer_size, st->rx_buf);
 	if (b_sent < 0)
 		goto out;

 	iio_push_to_buffers_with_timestamp(indio_dev, st->rx_buf,
 			iio_get_time_ns());
 out:
 	iio_trigger_notify_done(indio_dev->trig);

 	return IRQ_HANDLED;
 }

 static int ad799x_update_scan_mode(struct iio_dev *indio_dev,
 	const unsigned long *scan_mask)
 {
 	struct ad799x_state *st = iio_priv(indio_dev);

 	kfree(st->rx_buf);
 	st->rx_buf = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
 	if (!st->rx_buf)
 		return -ENOMEM;

 	st->transfer_size = bitmap_weight(scan_mask, indio_dev->masklength) * 2;

 	switch (st->id) {
 	case ad7992:
 	case ad7993:
 	case ad7994:
 	case ad7997:
 	case ad7998:
 		st->config &= ~(GENMASK(7, 0) << AD799X_CHANNEL_SHIFT);
 		st->config |= (*scan_mask << AD799X_CHANNEL_SHIFT);
 		return ad799x_write_config(st, st->config);
 	default:
 		return 0;
 	}
 }

 static int ad799x_scan_direct(struct ad799x_state *st, unsigned ch)
 {
 	u8 cmd;

 	switch (st->id) {
 	case ad7991:
 	case ad7995:
 	case ad7999:
 		cmd = st->config | (BIT(ch) << AD799X_CHANNEL_SHIFT);
 		break;
 	case ad7992:
 	case ad7993:
 	case ad7994:
 		cmd = BIT(ch) << AD799X_CHANNEL_SHIFT;
 		break;
 	case ad7997:
 	case ad7998:
 		cmd = (ch << AD799X_CHANNEL_SHIFT) | AD7997_8_READ_SINGLE;
 		break;
 	default:
 		return -EINVAL;
 	}

 	return i2c_smbus_read_word_swapped(st->client, cmd);
 }

 static int ad799x_read_raw(struct iio_dev *indio_dev,
 			   struct iio_chan_spec const *chan,
 			   int *val,
 			   int *val2,
 			   long m)
 {
 	int ret;
 	struct ad799x_state *st = iio_priv(indio_dev);

 	switch (m) {
 	case IIO_CHAN_INFO_RAW:
 		mutex_lock(&indio_dev->mlock);
 		if (iio_buffer_enabled(indio_dev))
 			ret = -EBUSY;
 		else
 			ret = ad799x_scan_direct(st, chan->scan_index);
 		mutex_unlock(&indio_dev->mlock);

 		if (ret < 0)
 			return ret;
 		*val = (ret >> chan->scan_type.shift) &
 			GENMASK(chan->scan_type.realbits - 1, 0);
 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_SCALE:
 		ret = regulator_get_voltage(st->vref);
 		if (ret < 0)
 			return ret;
 		*val = ret / 1000;
 		*val2 = chan->scan_type.realbits;
 		return IIO_VAL_FRACTIONAL_LOG2;
 	}
 	return -EINVAL;
 }
 static const unsigned int ad7998_frequencies[] = {
 	[AD7998_CYC_DIS]	= 0,
 	[AD7998_CYC_TCONF_32]	= 15625,
 	[AD7998_CYC_TCONF_64]	= 7812,
 	[AD7998_CYC_TCONF_128]	= 3906,
 	[AD7998_CYC_TCONF_512]	= 976,
 	[AD7998_CYC_TCONF_1024]	= 488,
 	[AD7998_CYC_TCONF_2048]	= 244,
 };

 static ssize_t ad799x_read_frequency(struct device *dev,
 					struct device_attribute *attr,
 					char *buf)
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct ad799x_state *st = iio_priv(indio_dev);

 	int ret = i2c_smbus_read_byte_data(st->client, AD7998_CYCLE_TMR_REG);
 	if (ret < 0)
 		return ret;

 	return sprintf(buf, "%u\n", ad7998_frequencies[ret & AD7998_CYC_MASK]);
 }

 static ssize_t ad799x_write_frequency(struct device *dev,
 					 struct device_attribute *attr,
 					 const char *buf,
 					 size_t len)
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct ad799x_state *st = iio_priv(indio_dev);

 	long val;
 	int ret, i;

 	ret = kstrtol(buf, 10, &val);
 	if (ret)
 		return ret;

 	mutex_lock(&indio_dev->mlock);
 	ret = i2c_smbus_read_byte_data(st->client, AD7998_CYCLE_TMR_REG);
 	if (ret < 0)
 		goto error_ret_mutex;
 	/* Wipe the bits clean */
 	ret &= ~AD7998_CYC_MASK;

 	for (i = 0; i < ARRAY_SIZE(ad7998_frequencies); i++)
 		if (val == ad7998_frequencies[i])
 			break;
 	if (i == ARRAY_SIZE(ad7998_frequencies)) {
 		ret = -EINVAL;
 		goto error_ret_mutex;
 	}

 	ret = i2c_smbus_write_byte_data(st->client, AD7998_CYCLE_TMR_REG,
 		ret | i);
 	if (ret < 0)
 		goto error_ret_mutex;
 	ret = len;

 error_ret_mutex:
 	mutex_unlock(&indio_dev->mlock);

 	return ret;
 }

 static int ad799x_read_event_config(struct iio_dev *indio_dev,
 				    const struct iio_chan_spec *chan,
 				    enum iio_event_type type,
 				    enum iio_event_direction dir)
 {
 	struct ad799x_state *st = iio_priv(indio_dev);

 	if (!(st->config & AD7998_ALERT_EN))
 		return 0;

 	if ((st->config >> AD799X_CHANNEL_SHIFT) & BIT(chan->scan_index))
 		return 1;

 	return 0;
 }

 static int ad799x_write_event_config(struct iio_dev *indio_dev,
 				     const struct iio_chan_spec *chan,
 				     enum iio_event_type type,
 				     enum iio_event_direction dir,
 				     int state)
 {
 	struct ad799x_state *st = iio_priv(indio_dev);
 	int ret;

 	mutex_lock(&indio_dev->mlock);
 	if (iio_buffer_enabled(indio_dev)) {
 		ret = -EBUSY;
 		goto done;
 	}

 	if (state)
 		st->config |= BIT(chan->scan_index) << AD799X_CHANNEL_SHIFT;
 	else
 		st->config &= ~(BIT(chan->scan_index) << AD799X_CHANNEL_SHIFT);

 	if (st->config >> AD799X_CHANNEL_SHIFT)
 		st->config |= AD7998_ALERT_EN;
 	else
 		st->config &= ~AD7998_ALERT_EN;

 	ret = ad799x_write_config(st, st->config);

 done:
 	mutex_unlock(&indio_dev->mlock);

 	return ret;
 }

 static unsigned int ad799x_threshold_reg(const struct iio_chan_spec *chan,
 					 enum iio_event_direction dir,
 					 enum iio_event_info info)
 {
 	switch (info) {
 	case IIO_EV_INFO_VALUE:
 		if (dir == IIO_EV_DIR_FALLING)
 			return AD7998_DATALOW_REG(chan->channel);
 		else
 			return AD7998_DATAHIGH_REG(chan->channel);
 	case IIO_EV_INFO_HYSTERESIS:
 		return AD7998_HYST_REG(chan->channel);
 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 static int ad799x_write_event_value(struct iio_dev *indio_dev,
 				    const struct iio_chan_spec *chan,
 				    enum iio_event_type type,
 				    enum iio_event_direction dir,
 				    enum iio_event_info info,
 				    int val, int val2)
 {
 	int ret;
 	struct ad799x_state *st = iio_priv(indio_dev);

 	if (val < 0 || val > GENMASK(chan->scan_type.realbits - 1, 0))
 		return -EINVAL;

 	mutex_lock(&indio_dev->mlock);
 	ret = i2c_smbus_write_word_swapped(st->client,
 		ad799x_threshold_reg(chan, dir, info),
 		val << chan->scan_type.shift);
 	mutex_unlock(&indio_dev->mlock);

 	return ret;
 }

 static int ad799x_read_event_value(struct iio_dev *indio_dev,
 				    const struct iio_chan_spec *chan,
 				    enum iio_event_type type,
 				    enum iio_event_direction dir,
 				    enum iio_event_info info,
 				    int *val, int *val2)
 {
 	int ret;
 	struct ad799x_state *st = iio_priv(indio_dev);

 	mutex_lock(&indio_dev->mlock);
 	ret = i2c_smbus_read_word_swapped(st->client,
 		ad799x_threshold_reg(chan, dir, info));
 	mutex_unlock(&indio_dev->mlock);
 	if (ret < 0)
 		return ret;
 	*val = (ret >> chan->scan_type.shift) &
 		GENMASK(chan->scan_type.realbits - 1 , 0);

 	return IIO_VAL_INT;
 }

 static irqreturn_t ad799x_event_handler(int irq, void *private)
 {
 	struct iio_dev *indio_dev = private;
 	struct ad799x_state *st = iio_priv(private);
 	int i, ret;

 	ret = i2c_smbus_read_byte_data(st->client, AD7998_ALERT_STAT_REG);
 	if (ret <= 0)
 		goto done;

 	if (i2c_smbus_write_byte_data(st->client, AD7998_ALERT_STAT_REG,
 		AD7998_ALERT_STAT_CLEAR) < 0)
 		goto done;

 	for (i = 0; i < 8; i++) {
 		if (ret & BIT(i))
 			iio_push_event(indio_dev,
 				       i & 0x1 ?
 				       IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE,
 							    (i >> 1),
 							    IIO_EV_TYPE_THRESH,
 							    IIO_EV_DIR_RISING) :
 				       IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE,
 							    (i >> 1),
 							    IIO_EV_TYPE_THRESH,
 							    IIO_EV_DIR_FALLING),
 				       iio_get_time_ns());
 	}

 done:
 	return IRQ_HANDLED;
 }

 static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO,
 			      ad799x_read_frequency,
 			      ad799x_write_frequency);
 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("15625 7812 3906 1953 976 488 244 0");

 static struct attribute *ad799x_event_attributes[] = {
 	&iio_dev_attr_sampling_frequency.dev_attr.attr,
 	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
 	NULL,
 };

 static struct attribute_group ad799x_event_attrs_group = {
 	.attrs = ad799x_event_attributes,
 	.name = "events",
 };

 static const struct iio_info ad7991_info = {
 	.read_raw = &ad799x_read_raw,
 	.driver_module = THIS_MODULE,
 };

 static const struct iio_info ad7993_4_7_8_noirq_info = {
 	.read_raw = &ad799x_read_raw,
 	.driver_module = THIS_MODULE,
 	.update_scan_mode = ad799x_update_scan_mode,
 };

 static const struct iio_info ad7993_4_7_8_irq_info = {
 	.read_raw = &ad799x_read_raw,
 	.event_attrs = &ad799x_event_attrs_group,
 	.read_event_config = &ad799x_read_event_config,
 	.write_event_config = &ad799x_write_event_config,
 	.read_event_value = &ad799x_read_event_value,
 	.write_event_value = &ad799x_write_event_value,
 	.driver_module = THIS_MODULE,
 	.update_scan_mode = ad799x_update_scan_mode,
 };

 static const struct iio_event_spec ad799x_events[] = {
 	{
 		.type = IIO_EV_TYPE_THRESH,
 		.dir = IIO_EV_DIR_RISING,
 		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
 			BIT(IIO_EV_INFO_ENABLE),
 	}, {
 		.type = IIO_EV_TYPE_THRESH,
 		.dir = IIO_EV_DIR_FALLING,
 		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
 			BIT(IIO_EV_INFO_ENABLE),
 	}, {
 		.type = IIO_EV_TYPE_THRESH,
 		.dir = IIO_EV_DIR_EITHER,
 		.mask_separate = BIT(IIO_EV_INFO_HYSTERESIS),
 	},
 };

 #define _AD799X_CHANNEL(_index, _realbits, _ev_spec, _num_ev_spec) { \
 	.type = IIO_VOLTAGE, \
 	.indexed = 1, \
 	.channel = (_index), \
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
 	.scan_index = (_index), \
 	.scan_type = { \
 		.sign = 'u', \
 		.realbits = (_realbits), \
 		.storagebits = 16, \
 		.shift = 12 - (_realbits), \
 		.endianness = IIO_BE, \
 	}, \
 	.event_spec = _ev_spec, \
 	.num_event_specs = _num_ev_spec, \
 }

 #define AD799X_CHANNEL(_index, _realbits) \
 	_AD799X_CHANNEL(_index, _realbits, NULL, 0)

 #define AD799X_CHANNEL_WITH_EVENTS(_index, _realbits) \
 	_AD799X_CHANNEL(_index, _realbits, ad799x_events, \
 		ARRAY_SIZE(ad799x_events))

 static const struct ad799x_chip_info ad799x_chip_info_tbl[] = {
 	[ad7991] = {
 		.num_channels = 5,
 		.noirq_config = {
 			.channel = {
 				AD799X_CHANNEL(0, 12),
 				AD799X_CHANNEL(1, 12),
 				AD799X_CHANNEL(2, 12),
 				AD799X_CHANNEL(3, 12),
 				IIO_CHAN_SOFT_TIMESTAMP(4),
 			},
 			.info = &ad7991_info,
 		},
 	},
 	[ad7995] = {
 		.num_channels = 5,
 		.noirq_config = {
 			.channel = {
 				AD799X_CHANNEL(0, 10),
 				AD799X_CHANNEL(1, 10),
 				AD799X_CHANNEL(2, 10),
 				AD799X_CHANNEL(3, 10),
 				IIO_CHAN_SOFT_TIMESTAMP(4),
 			},
 			.info = &ad7991_info,
 		},
 	},
 	[ad7999] = {
 		.num_channels = 5,
 		.noirq_config = {
 			.channel = {
 				AD799X_CHANNEL(0, 8),
 				AD799X_CHANNEL(1, 8),
 				AD799X_CHANNEL(2, 8),
 				AD799X_CHANNEL(3, 8),
 				IIO_CHAN_SOFT_TIMESTAMP(4),
 			},
 			.info = &ad7991_info,
 		},
 	},
 	[ad7992] = {
 		.num_channels = 3,
 		.noirq_config = {
 			.channel = {
 				AD799X_CHANNEL(0, 12),
 				AD799X_CHANNEL(1, 12),
 				IIO_CHAN_SOFT_TIMESTAMP(3),
 			},
 			.info = &ad7993_4_7_8_noirq_info,
 		},
 		.irq_config = {
 			.channel = {
 				AD799X_CHANNEL_WITH_EVENTS(0, 12),
 				AD799X_CHANNEL_WITH_EVENTS(1, 12),
 				IIO_CHAN_SOFT_TIMESTAMP(3),
 			},
 			.default_config = AD7998_ALERT_EN | AD7998_BUSY_ALERT,
 			.info = &ad7993_4_7_8_irq_info,
 		},
 	},
 	[ad7993] = {
 		.num_channels = 5,
 		.noirq_config = {
 			.channel = {
 				AD799X_CHANNEL(0, 10),
 				AD799X_CHANNEL(1, 10),
 				AD799X_CHANNEL(2, 10),
 				AD799X_CHANNEL(3, 10),
 				IIO_CHAN_SOFT_TIMESTAMP(4),
 			},
 			.info = &ad7993_4_7_8_noirq_info,
 		},
 		.irq_config = {
 			.channel = {
 				AD799X_CHANNEL_WITH_EVENTS(0, 10),
 				AD799X_CHANNEL_WITH_EVENTS(1, 10),
 				AD799X_CHANNEL_WITH_EVENTS(2, 10),
 				AD799X_CHANNEL_WITH_EVENTS(3, 10),
 				IIO_CHAN_SOFT_TIMESTAMP(4),
 			},
 			.default_config = AD7998_ALERT_EN | AD7998_BUSY_ALERT,
 			.info = &ad7993_4_7_8_irq_info,
 		},
 	},
 	[ad7994] = {
 		.num_channels = 5,
 		.noirq_config = {
 			.channel = {
 				AD799X_CHANNEL(0, 12),
 				AD799X_CHANNEL(1, 12),
 				AD799X_CHANNEL(2, 12),
 				AD799X_CHANNEL(3, 12),
 				IIO_CHAN_SOFT_TIMESTAMP(4),
 			},
 			.info = &ad7993_4_7_8_noirq_info,
 		},
 		.irq_config = {
 			.channel = {
 				AD799X_CHANNEL_WITH_EVENTS(0, 12),
 				AD799X_CHANNEL_WITH_EVENTS(1, 12),
 				AD799X_CHANNEL_WITH_EVENTS(2, 12),
 				AD799X_CHANNEL_WITH_EVENTS(3, 12),
 				IIO_CHAN_SOFT_TIMESTAMP(4),
 			},
 			.default_config = AD7998_ALERT_EN | AD7998_BUSY_ALERT,
 			.info = &ad7993_4_7_8_irq_info,
 		},
 	},
 	[ad7997] = {
 		.num_channels = 9,
 		.noirq_config = {
 			.channel = {
 				AD799X_CHANNEL(0, 10),
 				AD799X_CHANNEL(1, 10),
 				AD799X_CHANNEL(2, 10),
 				AD799X_CHANNEL(3, 10),
 				AD799X_CHANNEL(4, 10),
 				AD799X_CHANNEL(5, 10),
 				AD799X_CHANNEL(6, 10),
 				AD799X_CHANNEL(7, 10),
 				IIO_CHAN_SOFT_TIMESTAMP(8),
 			},
 			.info = &ad7993_4_7_8_noirq_info,
 		},
 		.irq_config = {
 			.channel = {
 				AD799X_CHANNEL_WITH_EVENTS(0, 10),
 				AD799X_CHANNEL_WITH_EVENTS(1, 10),
 				AD799X_CHANNEL_WITH_EVENTS(2, 10),
 				AD799X_CHANNEL_WITH_EVENTS(3, 10),
 				AD799X_CHANNEL(4, 10),
 				AD799X_CHANNEL(5, 10),
 				AD799X_CHANNEL(6, 10),
 				AD799X_CHANNEL(7, 10),
 				IIO_CHAN_SOFT_TIMESTAMP(8),
 			},
 			.default_config = AD7998_ALERT_EN | AD7998_BUSY_ALERT,
 			.info = &ad7993_4_7_8_irq_info,
 		},
 	},
 	[ad7998] = {
 		.num_channels = 9,
 		.noirq_config = {
 			.channel = {
 				AD799X_CHANNEL(0, 12),
 				AD799X_CHANNEL(1, 12),
 				AD799X_CHANNEL(2, 12),
 				AD799X_CHANNEL(3, 12),
 				AD799X_CHANNEL(4, 12),
 				AD799X_CHANNEL(5, 12),
 				AD799X_CHANNEL(6, 12),
 				AD799X_CHANNEL(7, 12),
 				IIO_CHAN_SOFT_TIMESTAMP(8),
 			},
 			.info = &ad7993_4_7_8_noirq_info,
 		},
 		.irq_config = {
 			.channel = {
 				AD799X_CHANNEL_WITH_EVENTS(0, 12),
 				AD799X_CHANNEL_WITH_EVENTS(1, 12),
 				AD799X_CHANNEL_WITH_EVENTS(2, 12),
 				AD799X_CHANNEL_WITH_EVENTS(3, 12),
 				AD799X_CHANNEL(4, 12),
 				AD799X_CHANNEL(5, 12),
 				AD799X_CHANNEL(6, 12),
 				AD799X_CHANNEL(7, 12),
 				IIO_CHAN_SOFT_TIMESTAMP(8),
 			},
 			.default_config = AD7998_ALERT_EN | AD7998_BUSY_ALERT,
 			.info = &ad7993_4_7_8_irq_info,
 		},
 	},
 };

 static int ad799x_probe(struct i2c_client *client,
 				   const struct i2c_device_id *id)
 {
 	int ret;
 	struct ad799x_state *st;
 	struct iio_dev *indio_dev;
 	const struct ad799x_chip_info *chip_info =
 		&ad799x_chip_info_tbl[id->driver_data];

 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
 	if (indio_dev == NULL)
 		return -ENOMEM;

 	st = iio_priv(indio_dev);
 	/* this is only used for device removal purposes */
 	i2c_set_clientdata(client, indio_dev);

 	st->id = id->driver_data;
 	if (client->irq > 0 && chip_info->irq_config.info)
 		st->chip_config = &chip_info->irq_config;
 	else
 		st->chip_config = &chip_info->noirq_config;

 	/* TODO: Add pdata options for filtering and bit delay */

 	st->reg = devm_regulator_get(&client->dev, "vcc");
 	if (IS_ERR(st->reg))
 		return PTR_ERR(st->reg);
 	ret = regulator_enable(st->reg);
 	if (ret)
 		return ret;
 	st->vref = devm_regulator_get(&client->dev, "vref");
 	if (IS_ERR(st->vref)) {
 		ret = PTR_ERR(st->vref);
 		goto error_disable_reg;
 	}
 	ret = regulator_enable(st->vref);
 	if (ret)
 		goto error_disable_reg;

 	st->client = client;

 	indio_dev->dev.parent = &client->dev;
 	indio_dev->name = id->name;
 	indio_dev->info = st->chip_config->info;

 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = st->chip_config->channel;
 	indio_dev->num_channels = chip_info->num_channels;

 	ret = ad799x_write_config(st, st->chip_config->default_config);
 	if (ret < 0)
 		goto error_disable_reg;
 	ret = ad799x_read_config(st);
 	if (ret < 0)
 		goto error_disable_reg;
 	st->config = ret;

 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
 		&ad799x_trigger_handler, NULL);
 	if (ret)
 		goto error_disable_vref;

 	if (client->irq > 0) {
 		ret = devm_request_threaded_irq(&client->dev,
 						client->irq,
 						NULL,
 						ad799x_event_handler,
 						IRQF_TRIGGER_FALLING |
 						IRQF_ONESHOT,
 						client->name,
 						indio_dev);
 		if (ret)
 			goto error_cleanup_ring;
 	}
 	ret = iio_device_register(indio_dev);
 	if (ret)
 		goto error_cleanup_ring;

 	return 0;

 error_cleanup_ring:
 	iio_triggered_buffer_cleanup(indio_dev);
 error_disable_vref:
 	regulator_disable(st->vref);
 error_disable_reg:
 	regulator_disable(st->reg);

 	return ret;
 }

 static int ad799x_remove(struct i2c_client *client)
 {
 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
 	struct ad799x_state *st = iio_priv(indio_dev);

 	iio_device_unregister(indio_dev);

 	iio_triggered_buffer_cleanup(indio_dev);
 	regulator_disable(st->vref);
 	regulator_disable(st->reg);
 	kfree(st->rx_buf);

 	return 0;
 }

 static const struct i2c_device_id ad799x_id[] = {
 	{ "ad7991", ad7991 },
 	{ "ad7995", ad7995 },
 	{ "ad7999", ad7999 },
 	{ "ad7992", ad7992 },
 	{ "ad7993", ad7993 },
 	{ "ad7994", ad7994 },
 	{ "ad7997", ad7997 },
 	{ "ad7998", ad7998 },
 	{}
 };

 MODULE_DEVICE_TABLE(i2c, ad799x_id);

 static struct i2c_driver ad799x_driver = {
 	.driver = {
 		.name = "ad799x",
 	},
 	.probe = ad799x_probe,
 	.remove = ad799x_remove,
 	.id_table = ad799x_id,
 };
 module_i2c_driver(ad799x_driver);

 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 MODULE_DESCRIPTION("Analog Devices AD799x ADC");
 MODULE_LICENSE("GPL v2");
	/*
	* iio/adc/ad799x.c
	* Copyright (C) 2010-2011 Michael Hennerich, Analog Devices Inc.
	*
	* based on iio/adc/max1363
	* Copyright (C) 2008-2010 Jonathan Cameron
	*
	* based on linux/drivers/i2c/chips/max123x
	* Copyright (C) 2002-2004 Stefan Eletzhofer
	*
	* based on linux/drivers/acron/char/pcf8583.c
	* Copyright (C) 2000 Russell King
	*
	* 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.
	*
	* ad799x.c
	*
	* Support for ad7991, ad7995, ad7999, ad7992, ad7993, ad7994, ad7997,
	* ad7998 and similar chips.
	*
	*/

	#include <linux/interrupt.h>
	#include <linux/device.h>
	#include <linux/kernel.h>
	#include <linux/sysfs.h>
	#include <linux/i2c.h>
	#include <linux/regulator/consumer.h>
	#include <linux/slab.h>
	#include <linux/types.h>
	#include <linux/err.h>
	#include <linux/module.h>
	#include <linux/bitops.h>

	#include <linux/iio/iio.h>
	#include <linux/iio/sysfs.h>
	#include <linux/iio/events.h>
	#include <linux/iio/buffer.h>
	#include <linux/iio/trigger_consumer.h>
	#include <linux/iio/triggered_buffer.h>

	#define AD799X_CHANNEL_SHIFT 4

	/*
	* AD7991, AD7995 and AD7999 defines
	*/

	#define AD7991_REF_SEL 0x08
	#define AD7991_FLTR 0x04
	#define AD7991_BIT_TRIAL_DELAY 0x02
	#define AD7991_SAMPLE_DELAY 0x01

	/*
	* AD7992, AD7993, AD7994, AD7997 and AD7998 defines
	*/

	#define AD7998_FLTR BIT(3)
	#define AD7998_ALERT_EN BIT(2)
	#define AD7998_BUSY_ALERT BIT(1)
	#define AD7998_BUSY_ALERT_POL BIT(0)

	#define AD7998_CONV_RES_REG 0x0
	#define AD7998_ALERT_STAT_REG 0x1
	#define AD7998_CONF_REG 0x2
	#define AD7998_CYCLE_TMR_REG 0x3

	#define AD7998_DATALOW_REG(x) ((x) * 3 + 0x4)
	#define AD7998_DATAHIGH_REG(x) ((x) * 3 + 0x5)
	#define AD7998_HYST_REG(x) ((x) * 3 + 0x6)

	#define AD7998_CYC_MASK GENMASK(2, 0)
	#define AD7998_CYC_DIS 0x0
	#define AD7998_CYC_TCONF_32 0x1
	#define AD7998_CYC_TCONF_64 0x2
	#define AD7998_CYC_TCONF_128 0x3
	#define AD7998_CYC_TCONF_256 0x4
	#define AD7998_CYC_TCONF_512 0x5
	#define AD7998_CYC_TCONF_1024 0x6
	#define AD7998_CYC_TCONF_2048 0x7

	#define AD7998_ALERT_STAT_CLEAR 0xFF

	/*
	* AD7997 and AD7997 defines
	*/

	#define AD7997_8_READ_SINGLE BIT(7)
	#define AD7997_8_READ_SEQUENCE (BIT(6) \| BIT(5) \| BIT(4))

	enum {
	ad7991,
	ad7995,
	ad7999,
	ad7992,
	ad7993,
	ad7994,
	ad7997,
	ad7998
	};

	/**
	* struct ad799x_chip_config - chip specific information
	* @channel: channel specification
	* @default_config: device default configuration
	* @info: pointer to iio_info struct
	*/
	struct ad799x_chip_config {
	const struct iio_chan_spec channel[9];
	u16 default_config;
	const struct iio_info *info;
	};

	/**
	* struct ad799x_chip_info - chip specific information
	* @num_channels: number of channels
	* @noirq_config: device configuration w/o IRQ
	* @irq_config: device configuration w/IRQ
	*/
	struct ad799x_chip_info {
	int num_channels;
	const struct ad799x_chip_config noirq_config;
	const struct ad799x_chip_config irq_config;
	};

	struct ad799x_state {
	struct i2c_client *client;
	const struct ad799x_chip_config *chip_config;
	struct regulator *reg;
	struct regulator *vref;
	unsigned id;
	u16 config;

	u8 *rx_buf;
	unsigned int transfer_size;
	};

	static int ad799x_write_config(struct ad799x_state *st, u16 val)
	{
	switch (st->id) {
	case ad7997:
	case ad7998:
	return i2c_smbus_write_word_swapped(st->client, AD7998_CONF_REG,
	val);
	case ad7992:
	case ad7993:
	case ad7994:
	return i2c_smbus_write_byte_data(st->client, AD7998_CONF_REG,
	val);
	default:
	/* Will be written when doing a conversion */
	st->config = val;
	return 0;
	}
	}

	static int ad799x_read_config(struct ad799x_state *st)
	{
	switch (st->id) {
	case ad7997:
	case ad7998:
	return i2c_smbus_read_word_swapped(st->client, AD7998_CONF_REG);
	case ad7992:
	case ad7993:
	case ad7994:
	return i2c_smbus_read_byte_data(st->client, AD7998_CONF_REG);
	default:
	/* No readback support */
	return st->config;
	}
	}

	/**
	* ad799x_trigger_handler() bh of trigger launched polling to ring buffer
	*
	* Currently there is no option in this driver to disable the saving of
	* timestamps within the ring.
	**/
	static irqreturn_t ad799x_trigger_handler(int irq, void *p)
	{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct ad799x_state *st = iio_priv(indio_dev);
	int b_sent;
	u8 cmd;

	switch (st->id) {
	case ad7991:
	case ad7995:
	case ad7999:
	cmd = st->config \|
	(*indio_dev->active_scan_mask << AD799X_CHANNEL_SHIFT);
	break;
	case ad7992:
	case ad7993:
	case ad7994:
	cmd = (*indio_dev->active_scan_mask << AD799X_CHANNEL_SHIFT) \|
	AD7998_CONV_RES_REG;
	break;
	case ad7997:
	case ad7998:
	cmd = AD7997_8_READ_SEQUENCE \| AD7998_CONV_RES_REG;
	break;
	default:
	cmd = 0;
	}

	b_sent = i2c_smbus_read_i2c_block_data(st->client,
	cmd, st->transfer_size, st->rx_buf);
	if (b_sent < 0)
	goto out;

	iio_push_to_buffers_with_timestamp(indio_dev, st->rx_buf,
	iio_get_time_ns());
	out:
	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
	}

	static int ad799x_update_scan_mode(struct iio_dev *indio_dev,
	const unsigned long *scan_mask)
	{
	struct ad799x_state *st = iio_priv(indio_dev);

	kfree(st->rx_buf);
	st->rx_buf = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
	if (!st->rx_buf)
	return -ENOMEM;

	st->transfer_size = bitmap_weight(scan_mask, indio_dev->masklength) * 2;

	switch (st->id) {
	case ad7992:
	case ad7993:
	case ad7994:
	case ad7997:
	case ad7998:
	st->config &= ~(GENMASK(7, 0) << AD799X_CHANNEL_SHIFT);
	st->config \|= (*scan_mask << AD799X_CHANNEL_SHIFT);
	return ad799x_write_config(st, st->config);
	default:
	return 0;
	}
	}

	static int ad799x_scan_direct(struct ad799x_state *st, unsigned ch)
	{
	u8 cmd;

	switch (st->id) {
	case ad7991:
	case ad7995:
	case ad7999:
	cmd = st->config \| (BIT(ch) << AD799X_CHANNEL_SHIFT);
	break;
	case ad7992:
	case ad7993:
	case ad7994:
	cmd = BIT(ch) << AD799X_CHANNEL_SHIFT;
	break;
	case ad7997:
	case ad7998:
	cmd = (ch << AD799X_CHANNEL_SHIFT) \| AD7997_8_READ_SINGLE;
	break;
	default:
	return -EINVAL;
	}

	return i2c_smbus_read_word_swapped(st->client, cmd);
	}

	static int ad799x_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int *val,
	int *val2,
	long m)
	{
	int ret;
	struct ad799x_state *st = iio_priv(indio_dev);

	switch (m) {
	case IIO_CHAN_INFO_RAW:
	mutex_lock(&indio_dev->mlock);
	if (iio_buffer_enabled(indio_dev))
	ret = -EBUSY;
	else
	ret = ad799x_scan_direct(st, chan->scan_index);
	mutex_unlock(&indio_dev->mlock);

	if (ret < 0)
	return ret;
	*val = (ret >> chan->scan_type.shift) &
	GENMASK(chan->scan_type.realbits - 1, 0);
	return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
	ret = regulator_get_voltage(st->vref);
	if (ret < 0)
	return ret;
	*val = ret / 1000;
	*val2 = chan->scan_type.realbits;
	return IIO_VAL_FRACTIONAL_LOG2;
	}
	return -EINVAL;
	}
	static const unsigned int ad7998_frequencies[] = {
	[AD7998_CYC_DIS] = 0,
	[AD7998_CYC_TCONF_32] = 15625,
	[AD7998_CYC_TCONF_64] = 7812,
	[AD7998_CYC_TCONF_128] = 3906,
	[AD7998_CYC_TCONF_512] = 976,
	[AD7998_CYC_TCONF_1024] = 488,
	[AD7998_CYC_TCONF_2048] = 244,
	};

	static ssize_t ad799x_read_frequency(struct device *dev,
	struct device_attribute *attr,
	char *buf)
	{
	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
	struct ad799x_state *st = iio_priv(indio_dev);

	int ret = i2c_smbus_read_byte_data(st->client, AD7998_CYCLE_TMR_REG);
	if (ret < 0)
	return ret;

	return sprintf(buf, "%u\n", ad7998_frequencies[ret & AD7998_CYC_MASK]);
	}

	static ssize_t ad799x_write_frequency(struct device *dev,
	struct device_attribute *attr,
	const char *buf,
	size_t len)
	{
	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
	struct ad799x_state *st = iio_priv(indio_dev);

	long val;
	int ret, i;

	ret = kstrtol(buf, 10, &val);
	if (ret)
	return ret;

	mutex_lock(&indio_dev->mlock);
	ret = i2c_smbus_read_byte_data(st->client, AD7998_CYCLE_TMR_REG);
	if (ret < 0)
	goto error_ret_mutex;
	/* Wipe the bits clean */
	ret &= ~AD7998_CYC_MASK;

	for (i = 0; i < ARRAY_SIZE(ad7998_frequencies); i++)
	if (val == ad7998_frequencies[i])
	break;
	if (i == ARRAY_SIZE(ad7998_frequencies)) {
	ret = -EINVAL;
	goto error_ret_mutex;
	}

	ret = i2c_smbus_write_byte_data(st->client, AD7998_CYCLE_TMR_REG,
	ret \| i);
	if (ret < 0)
	goto error_ret_mutex;
	ret = len;

	error_ret_mutex:
	mutex_unlock(&indio_dev->mlock);

	return ret;
	}

	static int ad799x_read_event_config(struct iio_dev *indio_dev,
	const struct iio_chan_spec *chan,
	enum iio_event_type type,
	enum iio_event_direction dir)
	{
	struct ad799x_state *st = iio_priv(indio_dev);

	if (!(st->config & AD7998_ALERT_EN))
	return 0;

	if ((st->config >> AD799X_CHANNEL_SHIFT) & BIT(chan->scan_index))
	return 1;

	return 0;
	}

	static int ad799x_write_event_config(struct iio_dev *indio_dev,
	const struct iio_chan_spec *chan,
	enum iio_event_type type,
	enum iio_event_direction dir,
	int state)
	{
	struct ad799x_state *st = iio_priv(indio_dev);
	int ret;

	mutex_lock(&indio_dev->mlock);
	if (iio_buffer_enabled(indio_dev)) {
	ret = -EBUSY;
	goto done;
	}

	if (state)
	st->config \|= BIT(chan->scan_index) << AD799X_CHANNEL_SHIFT;
	else
	st->config &= ~(BIT(chan->scan_index) << AD799X_CHANNEL_SHIFT);

	if (st->config >> AD799X_CHANNEL_SHIFT)
	st->config \|= AD7998_ALERT_EN;
	else
	st->config &= ~AD7998_ALERT_EN;

	ret = ad799x_write_config(st, st->config);

	done:
	mutex_unlock(&indio_dev->mlock);

	return ret;
	}

	static unsigned int ad799x_threshold_reg(const struct iio_chan_spec *chan,
	enum iio_event_direction dir,
	enum iio_event_info info)
	{
	switch (info) {
	case IIO_EV_INFO_VALUE:
	if (dir == IIO_EV_DIR_FALLING)
	return AD7998_DATALOW_REG(chan->channel);
	else
	return AD7998_DATAHIGH_REG(chan->channel);
	case IIO_EV_INFO_HYSTERESIS:
	return AD7998_HYST_REG(chan->channel);
	default:
	return -EINVAL;
	}

	return 0;
	}

	static int ad799x_write_event_value(struct iio_dev *indio_dev,
	const struct iio_chan_spec *chan,
	enum iio_event_type type,
	enum iio_event_direction dir,
	enum iio_event_info info,
	int val, int val2)
	{
	int ret;
	struct ad799x_state *st = iio_priv(indio_dev);

	if (val < 0 \|\| val > GENMASK(chan->scan_type.realbits - 1, 0))
	return -EINVAL;

	mutex_lock(&indio_dev->mlock);
	ret = i2c_smbus_write_word_swapped(st->client,
	ad799x_threshold_reg(chan, dir, info),
	val << chan->scan_type.shift);
	mutex_unlock(&indio_dev->mlock);

	return ret;
	}

	static int ad799x_read_event_value(struct iio_dev *indio_dev,
	const struct iio_chan_spec *chan,
	enum iio_event_type type,
	enum iio_event_direction dir,
	enum iio_event_info info,
	int val, int val2)
	{
	int ret;
	struct ad799x_state *st = iio_priv(indio_dev);

	mutex_lock(&indio_dev->mlock);
	ret = i2c_smbus_read_word_swapped(st->client,
	ad799x_threshold_reg(chan, dir, info));
	mutex_unlock(&indio_dev->mlock);
	if (ret < 0)
	return ret;
	*val = (ret >> chan->scan_type.shift) &
	GENMASK(chan->scan_type.realbits - 1 , 0);

	return IIO_VAL_INT;
	}

	static irqreturn_t ad799x_event_handler(int irq, void *private)
	{
	struct iio_dev *indio_dev = private;
	struct ad799x_state *st = iio_priv(private);
	int i, ret;

	ret = i2c_smbus_read_byte_data(st->client, AD7998_ALERT_STAT_REG);
	if (ret <= 0)
	goto done;

	if (i2c_smbus_write_byte_data(st->client, AD7998_ALERT_STAT_REG,
	AD7998_ALERT_STAT_CLEAR) < 0)
	goto done;

	for (i = 0; i < 8; i++) {
	if (ret & BIT(i))
	iio_push_event(indio_dev,
	i & 0x1 ?
	IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE,
	(i >> 1),
	IIO_EV_TYPE_THRESH,
	IIO_EV_DIR_RISING) :
	IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE,
	(i >> 1),
	IIO_EV_TYPE_THRESH,
	IIO_EV_DIR_FALLING),
	iio_get_time_ns());
	}

	done:
	return IRQ_HANDLED;
	}

	static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR \| S_IRUGO,
	ad799x_read_frequency,
	ad799x_write_frequency);
	static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("15625 7812 3906 1953 976 488 244 0");

	static struct attribute *ad799x_event_attributes[] = {
	&iio_dev_attr_sampling_frequency.dev_attr.attr,
	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
	NULL,
	};

	static struct attribute_group ad799x_event_attrs_group = {
	.attrs = ad799x_event_attributes,
	.name = "events",
	};

	static const struct iio_info ad7991_info = {
	.read_raw = &ad799x_read_raw,
	.driver_module = THIS_MODULE,
	};

	static const struct iio_info ad7993_4_7_8_noirq_info = {
	.read_raw = &ad799x_read_raw,
	.driver_module = THIS_MODULE,
	.update_scan_mode = ad799x_update_scan_mode,
	};

	static const struct iio_info ad7993_4_7_8_irq_info = {
	.read_raw = &ad799x_read_raw,
	.event_attrs = &ad799x_event_attrs_group,
	.read_event_config = &ad799x_read_event_config,
	.write_event_config = &ad799x_write_event_config,
	.read_event_value = &ad799x_read_event_value,
	.write_event_value = &ad799x_write_event_value,
	.driver_module = THIS_MODULE,
	.update_scan_mode = ad799x_update_scan_mode,
	};

	static const struct iio_event_spec ad799x_events[] = {
	{
	.type = IIO_EV_TYPE_THRESH,
	.dir = IIO_EV_DIR_RISING,
	.mask_separate = BIT(IIO_EV_INFO_VALUE) \|
	BIT(IIO_EV_INFO_ENABLE),
	}, {
	.type = IIO_EV_TYPE_THRESH,
	.dir = IIO_EV_DIR_FALLING,
	.mask_separate = BIT(IIO_EV_INFO_VALUE) \|
	BIT(IIO_EV_INFO_ENABLE),
	}, {
	.type = IIO_EV_TYPE_THRESH,
	.dir = IIO_EV_DIR_EITHER,
	.mask_separate = BIT(IIO_EV_INFO_HYSTERESIS),
	},
	};

	#define _AD799X_CHANNEL(_index, _realbits, _ev_spec, _num_ev_spec) { \
	.type = IIO_VOLTAGE, \
	.indexed = 1, \
	.channel = (_index), \
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
	.scan_index = (_index), \
	.scan_type = { \
	.sign = 'u', \
	.realbits = (_realbits), \
	.storagebits = 16, \
	.shift = 12 - (_realbits), \
	.endianness = IIO_BE, \
	}, \
	.event_spec = _ev_spec, \
	.num_event_specs = _num_ev_spec, \
	}

	#define AD799X_CHANNEL(_index, _realbits) \
	_AD799X_CHANNEL(_index, _realbits, NULL, 0)

	#define AD799X_CHANNEL_WITH_EVENTS(_index, _realbits) \
	_AD799X_CHANNEL(_index, _realbits, ad799x_events, \
	ARRAY_SIZE(ad799x_events))

	static const struct ad799x_chip_info ad799x_chip_info_tbl[] = {
	[ad7991] = {
	.num_channels = 5,
	.noirq_config = {
	.channel = {
	AD799X_CHANNEL(0, 12),
	AD799X_CHANNEL(1, 12),
	AD799X_CHANNEL(2, 12),
	AD799X_CHANNEL(3, 12),
	IIO_CHAN_SOFT_TIMESTAMP(4),
	},
	.info = &ad7991_info,
	},
	},
	[ad7995] = {
	.num_channels = 5,
	.noirq_config = {
	.channel = {
	AD799X_CHANNEL(0, 10),
	AD799X_CHANNEL(1, 10),
	AD799X_CHANNEL(2, 10),
	AD799X_CHANNEL(3, 10),
	IIO_CHAN_SOFT_TIMESTAMP(4),
	},
	.info = &ad7991_info,
	},
	},
	[ad7999] = {
	.num_channels = 5,
	.noirq_config = {
	.channel = {
	AD799X_CHANNEL(0, 8),
	AD799X_CHANNEL(1, 8),
	AD799X_CHANNEL(2, 8),
	AD799X_CHANNEL(3, 8),
	IIO_CHAN_SOFT_TIMESTAMP(4),
	},
	.info = &ad7991_info,
	},
	},
	[ad7992] = {
	.num_channels = 3,
	.noirq_config = {
	.channel = {
	AD799X_CHANNEL(0, 12),
	AD799X_CHANNEL(1, 12),
	IIO_CHAN_SOFT_TIMESTAMP(3),
	},
	.info = &ad7993_4_7_8_noirq_info,
	},
	.irq_config = {
	.channel = {
	AD799X_CHANNEL_WITH_EVENTS(0, 12),
	AD799X_CHANNEL_WITH_EVENTS(1, 12),
	IIO_CHAN_SOFT_TIMESTAMP(3),
	},
	.default_config = AD7998_ALERT_EN \| AD7998_BUSY_ALERT,
	.info = &ad7993_4_7_8_irq_info,
	},
	},
	[ad7993] = {
	.num_channels = 5,
	.noirq_config = {
	.channel = {
	AD799X_CHANNEL(0, 10),
	AD799X_CHANNEL(1, 10),
	AD799X_CHANNEL(2, 10),
	AD799X_CHANNEL(3, 10),
	IIO_CHAN_SOFT_TIMESTAMP(4),
	},
	.info = &ad7993_4_7_8_noirq_info,
	},
	.irq_config = {
	.channel = {
	AD799X_CHANNEL_WITH_EVENTS(0, 10),
	AD799X_CHANNEL_WITH_EVENTS(1, 10),
	AD799X_CHANNEL_WITH_EVENTS(2, 10),
	AD799X_CHANNEL_WITH_EVENTS(3, 10),
	IIO_CHAN_SOFT_TIMESTAMP(4),
	},
	.default_config = AD7998_ALERT_EN \| AD7998_BUSY_ALERT,
	.info = &ad7993_4_7_8_irq_info,
	},
	},
	[ad7994] = {
	.num_channels = 5,
	.noirq_config = {
	.channel = {
	AD799X_CHANNEL(0, 12),
	AD799X_CHANNEL(1, 12),
	AD799X_CHANNEL(2, 12),
	AD799X_CHANNEL(3, 12),
	IIO_CHAN_SOFT_TIMESTAMP(4),
	},
	.info = &ad7993_4_7_8_noirq_info,
	},
	.irq_config = {
	.channel = {
	AD799X_CHANNEL_WITH_EVENTS(0, 12),
	AD799X_CHANNEL_WITH_EVENTS(1, 12),
	AD799X_CHANNEL_WITH_EVENTS(2, 12),
	AD799X_CHANNEL_WITH_EVENTS(3, 12),
	IIO_CHAN_SOFT_TIMESTAMP(4),
	},
	.default_config = AD7998_ALERT_EN \| AD7998_BUSY_ALERT,
	.info = &ad7993_4_7_8_irq_info,
	},
	},
	[ad7997] = {
	.num_channels = 9,
	.noirq_config = {
	.channel = {
	AD799X_CHANNEL(0, 10),
	AD799X_CHANNEL(1, 10),
	AD799X_CHANNEL(2, 10),
	AD799X_CHANNEL(3, 10),
	AD799X_CHANNEL(4, 10),
	AD799X_CHANNEL(5, 10),
	AD799X_CHANNEL(6, 10),
	AD799X_CHANNEL(7, 10),
	IIO_CHAN_SOFT_TIMESTAMP(8),
	},
	.info = &ad7993_4_7_8_noirq_info,
	},
	.irq_config = {
	.channel = {
	AD799X_CHANNEL_WITH_EVENTS(0, 10),
	AD799X_CHANNEL_WITH_EVENTS(1, 10),
	AD799X_CHANNEL_WITH_EVENTS(2, 10),
	AD799X_CHANNEL_WITH_EVENTS(3, 10),
	AD799X_CHANNEL(4, 10),
	AD799X_CHANNEL(5, 10),
	AD799X_CHANNEL(6, 10),
	AD799X_CHANNEL(7, 10),
	IIO_CHAN_SOFT_TIMESTAMP(8),
	},
	.default_config = AD7998_ALERT_EN \| AD7998_BUSY_ALERT,
	.info = &ad7993_4_7_8_irq_info,
	},
	},
	[ad7998] = {
	.num_channels = 9,
	.noirq_config = {
	.channel = {
	AD799X_CHANNEL(0, 12),
	AD799X_CHANNEL(1, 12),
	AD799X_CHANNEL(2, 12),
	AD799X_CHANNEL(3, 12),
	AD799X_CHANNEL(4, 12),
	AD799X_CHANNEL(5, 12),
	AD799X_CHANNEL(6, 12),
	AD799X_CHANNEL(7, 12),
	IIO_CHAN_SOFT_TIMESTAMP(8),
	},
	.info = &ad7993_4_7_8_noirq_info,
	},
	.irq_config = {
	.channel = {
	AD799X_CHANNEL_WITH_EVENTS(0, 12),
	AD799X_CHANNEL_WITH_EVENTS(1, 12),
	AD799X_CHANNEL_WITH_EVENTS(2, 12),
	AD799X_CHANNEL_WITH_EVENTS(3, 12),
	AD799X_CHANNEL(4, 12),
	AD799X_CHANNEL(5, 12),
	AD799X_CHANNEL(6, 12),
	AD799X_CHANNEL(7, 12),
	IIO_CHAN_SOFT_TIMESTAMP(8),
	},
	.default_config = AD7998_ALERT_EN \| AD7998_BUSY_ALERT,
	.info = &ad7993_4_7_8_irq_info,
	},
	},
	};

	static int ad799x_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	int ret;
	struct ad799x_state *st;
	struct iio_dev *indio_dev;
	const struct ad799x_chip_info *chip_info =
	&ad799x_chip_info_tbl[id->driver_data];

	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
	if (indio_dev == NULL)
	return -ENOMEM;

	st = iio_priv(indio_dev);
	/* this is only used for device removal purposes */
	i2c_set_clientdata(client, indio_dev);

	st->id = id->driver_data;
	if (client->irq > 0 && chip_info->irq_config.info)
	st->chip_config = &chip_info->irq_config;
	else
	st->chip_config = &chip_info->noirq_config;

	/* TODO: Add pdata options for filtering and bit delay */

	st->reg = devm_regulator_get(&client->dev, "vcc");
	if (IS_ERR(st->reg))
	return PTR_ERR(st->reg);
	ret = regulator_enable(st->reg);
	if (ret)
	return ret;
	st->vref = devm_regulator_get(&client->dev, "vref");
	if (IS_ERR(st->vref)) {
	ret = PTR_ERR(st->vref);
	goto error_disable_reg;
	}
	ret = regulator_enable(st->vref);
	if (ret)
	goto error_disable_reg;

	st->client = client;

	indio_dev->dev.parent = &client->dev;
	indio_dev->name = id->name;
	indio_dev->info = st->chip_config->info;

	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = st->chip_config->channel;
	indio_dev->num_channels = chip_info->num_channels;

	ret = ad799x_write_config(st, st->chip_config->default_config);
	if (ret < 0)
	goto error_disable_reg;
	ret = ad799x_read_config(st);
	if (ret < 0)
	goto error_disable_reg;
	st->config = ret;

	ret = iio_triggered_buffer_setup(indio_dev, NULL,
	&ad799x_trigger_handler, NULL);
	if (ret)
	goto error_disable_vref;

	if (client->irq > 0) {
	ret = devm_request_threaded_irq(&client->dev,
	client->irq,
	NULL,
	ad799x_event_handler,
	IRQF_TRIGGER_FALLING \|
	IRQF_ONESHOT,
	client->name,
	indio_dev);
	if (ret)
	goto error_cleanup_ring;
	}
	ret = iio_device_register(indio_dev);
	if (ret)
	goto error_cleanup_ring;

	return 0;

	error_cleanup_ring:
	iio_triggered_buffer_cleanup(indio_dev);
	error_disable_vref:
	regulator_disable(st->vref);
	error_disable_reg:
	regulator_disable(st->reg);

	return ret;
	}

	static int ad799x_remove(struct i2c_client *client)
	{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);
	struct ad799x_state *st = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);

	iio_triggered_buffer_cleanup(indio_dev);
	regulator_disable(st->vref);
	regulator_disable(st->reg);
	kfree(st->rx_buf);

	return 0;
	}

	static const struct i2c_device_id ad799x_id[] = {
	{ "ad7991", ad7991 },
	{ "ad7995", ad7995 },
	{ "ad7999", ad7999 },
	{ "ad7992", ad7992 },
	{ "ad7993", ad7993 },
	{ "ad7994", ad7994 },
	{ "ad7997", ad7997 },
	{ "ad7998", ad7998 },
	{}
	};

	MODULE_DEVICE_TABLE(i2c, ad799x_id);

	static struct i2c_driver ad799x_driver = {
	.driver = {
	.name = "ad799x",
	},
	.probe = ad799x_probe,
	.remove = ad799x_remove,
	.id_table = ad799x_id,
	};
	module_i2c_driver(ad799x_driver);

	MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
	MODULE_DESCRIPTION("Analog Devices AD799x ADC");
	MODULE_LICENSE("GPL v2");