root/drivers/iio/adc/ad799x.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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
 *
 * 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/mutex.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
 * @has_vref:           device supports external reference voltage
 */
struct ad799x_chip_info {
        int                             num_channels;
        const struct ad799x_chip_config noirq_config;
        const struct ad799x_chip_config irq_config;
        bool has_vref;
};

struct ad799x_state {
        struct i2c_client               *client;
        const struct ad799x_chip_config *chip_config;
        struct regulator                *reg;
        struct regulator                *vref;
        /* lock to protect against multiple access to the device */
        struct mutex                    lock;
        unsigned int                    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;
        }
}

static int ad799x_update_config(struct ad799x_state *st, u16 config)
{
        int ret;

        ret = ad799x_write_config(st, config);
        if (ret < 0)
                return ret;
        ret = ad799x_read_config(st);
        if (ret < 0)
                return ret;
        st->config = ret;

        return 0;
}

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(indio_dev));
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,
                                          iio_get_masklength(indio_dev)) * 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 int 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:
                if (!iio_device_claim_direct(indio_dev))
                        return -EBUSY;
                mutex_lock(&st->lock);
                ret = ad799x_scan_direct(st, chan->scan_index);
                mutex_unlock(&st->lock);
                iio_device_release_direct(indio_dev);

                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:
                if (st->vref)
                        ret = regulator_get_voltage(st->vref);
                else
                        ret = regulator_get_voltage(st->reg);

                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(&st->lock);

        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(&st->lock);

        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,
                                     bool state)
{
        struct ad799x_state *st = iio_priv(indio_dev);
        int ret;

        if (!iio_device_claim_direct(indio_dev))
                return -EBUSY;

        mutex_lock(&st->lock);

        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);
        mutex_unlock(&st->lock);
        iio_device_release_direct(indio_dev);
        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;

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

        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);

        ret = i2c_smbus_read_word_swapped(st->client,
                ad799x_threshold_reg(chan, dir, info));
        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(indio_dev));
        }

done:
        return IRQ_HANDLED;
}

static IIO_DEV_ATTR_SAMP_FREQ(0644,
                              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 const struct attribute_group ad799x_event_attrs_group = {
        .attrs = ad799x_event_attributes,
};

static const struct iio_info ad7991_info = {
        .read_raw = &ad799x_read_raw,
        .update_scan_mode = ad799x_update_scan_mode,
};

static const struct iio_info ad7993_4_7_8_noirq_info = {
        .read_raw = &ad799x_read_raw,
        .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,
        .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,
                .has_vref = true,
                .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,
                .has_vref = true,
                .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,
                .has_vref = true,
                .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,
                .has_vref = true,
                .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 = i2c_client_get_device_id(client);
        int ret;
        int extra_config = 0;
        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;

        /* check if an external reference is supplied */
        if (chip_info->has_vref) {
                st->vref = devm_regulator_get_optional(&client->dev, "vref");
                ret = PTR_ERR_OR_ZERO(st->vref);
                if (ret) {
                        if (ret != -ENODEV)
                                goto error_disable_reg;
                        st->vref = NULL;
                        dev_info(&client->dev, "Using VCC reference voltage\n");
                }

                if (st->vref) {
                        dev_info(&client->dev, "Using external reference voltage\n");
                        extra_config |= AD7991_REF_SEL;
                        ret = regulator_enable(st->vref);
                        if (ret)
                                goto error_disable_reg;
                }
        }

        st->client = client;

        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_update_config(st, st->chip_config->default_config | extra_config);
        if (ret)
                goto error_disable_vref;

        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;
        }

        mutex_init(&st->lock);

        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:
        if (st->vref)
                regulator_disable(st->vref);
error_disable_reg:
        regulator_disable(st->reg);

        return ret;
}

static void 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);
        if (st->vref)
                regulator_disable(st->vref);
        regulator_disable(st->reg);
        kfree(st->rx_buf);
}

static int ad799x_suspend(struct device *dev)
{
        struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
        struct ad799x_state *st = iio_priv(indio_dev);

        if (st->vref)
                regulator_disable(st->vref);
        regulator_disable(st->reg);

        return 0;
}

static int ad799x_resume(struct device *dev)
{
        struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
        struct ad799x_state *st = iio_priv(indio_dev);
        int ret;

        ret = regulator_enable(st->reg);
        if (ret) {
                dev_err(dev, "Unable to enable vcc regulator\n");
                return ret;
        }

        if (st->vref) {
                ret = regulator_enable(st->vref);
                if (ret) {
                        regulator_disable(st->reg);
                        dev_err(dev, "Unable to enable vref regulator\n");
                        return ret;
                }
        }

        /* resync config */
        ret = ad799x_update_config(st, st->config);
        if (ret) {
                if (st->vref)
                        regulator_disable(st->vref);
                regulator_disable(st->reg);
                return ret;
        }

        return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(ad799x_pm_ops, ad799x_suspend, ad799x_resume);

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",
                .pm = pm_sleep_ptr(&ad799x_pm_ops),
        },
        .probe = ad799x_probe,
        .remove = ad799x_remove,
        .id_table = ad799x_id,
};
module_i2c_driver(ad799x_driver);

MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD799x ADC");
MODULE_LICENSE("GPL v2");