// SPDX-License-Identifier: GPL-2.0-only
/*
 * AD7785/AD7792/AD7793/AD7794/AD7795 SPI ADC driver
 *
 * Copyright 2011-2012 Analog Devices Inc.
 */

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

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/adc/ad_sigma_delta.h>
#include <linux/platform_data/ad7793.h>

/* Registers */
#define AD7793_REG_COMM         0 /* Communications Register (WO, 8-bit) */
#define AD7793_REG_STAT         0 /* Status Register         (RO, 8-bit) */
#define AD7793_REG_MODE         1 /* Mode Register           (RW, 16-bit */
#define AD7793_REG_CONF         2 /* Configuration Register  (RW, 16-bit) */
#define AD7793_REG_DATA         3 /* Data Register           (RO, 16-/24-bit) */
#define AD7793_REG_ID           4 /* ID Register             (RO, 8-bit) */
#define AD7793_REG_IO           5 /* IO Register             (RO, 8-bit) */
#define AD7793_REG_OFFSET       6 /* Offset Register         (RW, 16-bit
                                   * (AD7792)/24-bit (AD7793)) */
#define AD7793_REG_FULLSALE     7 /* Full-Scale Register
                                   * (RW, 16-bit (AD7792)/24-bit (AD7793)) */

/* Communications Register Bit Designations (AD7793_REG_COMM) */
#define AD7793_COMM_WEN         (1 << 7) /* Write Enable */
#define AD7793_COMM_WRITE       (0 << 6) /* Write Operation */
#define AD7793_COMM_READ        (1 << 6) /* Read Operation */
#define AD7793_COMM_ADDR(x)     (((x) & 0x7) << 3) /* Register Address */
#define AD7793_COMM_CREAD       (1 << 2) /* Continuous Read of Data Register */

/* Status Register Bit Designations (AD7793_REG_STAT) */
#define AD7793_STAT_RDY         (1 << 7) /* Ready */
#define AD7793_STAT_ERR         (1 << 6) /* Error (Overrange, Underrange) */
#define AD7793_STAT_CH3         (1 << 2) /* Channel 3 */
#define AD7793_STAT_CH2         (1 << 1) /* Channel 2 */
#define AD7793_STAT_CH1         (1 << 0) /* Channel 1 */

/* Mode Register Bit Designations (AD7793_REG_MODE) */
#define AD7793_MODE_SEL(x)      (((x) & 0x7) << 13) /* Operation Mode Select */
#define AD7793_MODE_SEL_MASK    (0x7 << 13) /* Operation Mode Select mask */
#define AD7793_MODE_CLKSRC(x)   (((x) & 0x3) << 6) /* ADC Clock Source Select */
#define AD7793_MODE_RATE(x)     ((x) & 0xF) /* Filter Update Rate Select */

#define AD7793_MODE_CONT                0 /* Continuous Conversion Mode */
#define AD7793_MODE_SINGLE              1 /* Single Conversion Mode */
#define AD7793_MODE_IDLE                2 /* Idle Mode */
#define AD7793_MODE_PWRDN               3 /* Power-Down Mode */
#define AD7793_MODE_CAL_INT_ZERO        4 /* Internal Zero-Scale Calibration */
#define AD7793_MODE_CAL_INT_FULL        5 /* Internal Full-Scale Calibration */
#define AD7793_MODE_CAL_SYS_ZERO        6 /* System Zero-Scale Calibration */
#define AD7793_MODE_CAL_SYS_FULL        7 /* System Full-Scale Calibration */

#define AD7793_CLK_INT          0 /* Internal 64 kHz Clock not
                                   * available at the CLK pin */
#define AD7793_CLK_INT_CO       1 /* Internal 64 kHz Clock available
                                   * at the CLK pin */
#define AD7793_CLK_EXT          2 /* External 64 kHz Clock */
#define AD7793_CLK_EXT_DIV2     3 /* External Clock divided by 2 */

/* Configuration Register Bit Designations (AD7793_REG_CONF) */
#define AD7793_CONF_VBIAS(x)    (((x) & 0x3) << 14) /* Bias Voltage
                                                     * Generator Enable */
#define AD7793_CONF_BO_EN       (1 << 13) /* Burnout Current Enable */
#define AD7793_CONF_UNIPOLAR    (1 << 12) /* Unipolar/Bipolar Enable */
#define AD7793_CONF_BOOST       (1 << 11) /* Boost Enable */
#define AD7793_CONF_GAIN(x)     (((x) & 0x7) << 8) /* Gain Select */
#define AD7793_CONF_REFSEL(x)   ((x) << 6) /* INT/EXT Reference Select */
#define AD7793_CONF_BUF         (1 << 4) /* Buffered Mode Enable */
#define AD7793_CONF_CHAN(x)     ((x) & 0xf) /* Channel select */
#define AD7793_CONF_CHAN_MASK   0xf /* Channel select mask */

#define AD7793_CH_AIN1P_AIN1M   0 /* AIN1(+) - AIN1(-) */
#define AD7793_CH_AIN2P_AIN2M   1 /* AIN2(+) - AIN2(-) */
#define AD7793_CH_AIN3P_AIN3M   2 /* AIN3(+) - AIN3(-) */
#define AD7793_CH_AIN1M_AIN1M   3 /* AIN1(-) - AIN1(-) */
#define AD7793_CH_TEMP          6 /* Temp Sensor */
#define AD7793_CH_AVDD_MONITOR  7 /* AVDD Monitor */

#define AD7795_CH_AIN4P_AIN4M   4 /* AIN4(+) - AIN4(-) */
#define AD7795_CH_AIN5P_AIN5M   5 /* AIN5(+) - AIN5(-) */
#define AD7795_CH_AIN6P_AIN6M   6 /* AIN6(+) - AIN6(-) */
#define AD7795_CH_AIN1M_AIN1M   8 /* AIN1(-) - AIN1(-) */

/* ID Register Bit Designations (AD7793_REG_ID) */
#define AD7785_ID               0x3
#define AD7792_ID               0xA
#define AD7793_ID               0xB
#define AD7794_ID               0xF
#define AD7795_ID               0xF
#define AD7796_ID               0xA
#define AD7797_ID               0xB
#define AD7798_ID               0x8
#define AD7799_ID               0x9
#define AD7793_ID_MASK          0xF

/* IO (Excitation Current Sources) Register Bit Designations (AD7793_REG_IO) */
#define AD7793_IO_IEXC1_IOUT1_IEXC2_IOUT2       0 /* IEXC1 connect to IOUT1,
                                                   * IEXC2 connect to IOUT2 */
#define AD7793_IO_IEXC1_IOUT2_IEXC2_IOUT1       1 /* IEXC1 connect to IOUT2,
                                                   * IEXC2 connect to IOUT1 */
#define AD7793_IO_IEXC1_IEXC2_IOUT1             2 /* Both current sources
                                                   * IEXC1,2 connect to IOUT1 */
#define AD7793_IO_IEXC1_IEXC2_IOUT2             3 /* Both current sources
                                                   * IEXC1,2 connect to IOUT2 */

#define AD7793_IO_IXCEN_10uA    (1 << 0) /* Excitation Current 10uA */
#define AD7793_IO_IXCEN_210uA   (2 << 0) /* Excitation Current 210uA */
#define AD7793_IO_IXCEN_1mA     (3 << 0) /* Excitation Current 1mA */

/* NOTE:
 * The AD7792/AD7793 features a dual use data out ready DOUT/RDY output.
 * In order to avoid contentions on the SPI bus, it's therefore necessary
 * to use spi bus locking.
 *
 * The DOUT/RDY output must also be wired to an interrupt capable GPIO.
 */

#define AD7793_FLAG_HAS_CLKSEL          BIT(0)
#define AD7793_FLAG_HAS_REFSEL          BIT(1)
#define AD7793_FLAG_HAS_VBIAS           BIT(2)
#define AD7793_HAS_EXITATION_CURRENT    BIT(3)
#define AD7793_FLAG_HAS_GAIN            BIT(4)
#define AD7793_FLAG_HAS_BUFFER          BIT(5)

struct ad7793_chip_info {
        unsigned int id;
        const struct iio_chan_spec *channels;
        unsigned int num_channels;
        unsigned int flags;

        const struct iio_info *iio_info;
        const u16 *sample_freq_avail;
};

struct ad7793_state {
        const struct ad7793_chip_info   *chip_info;
        u16                             int_vref_mv;
        u16                             mode;
        u16                             conf;
        u32                             scale_avail[8][2];

        struct ad_sigma_delta           sd;

};

enum ad7793_supported_device_ids {
        ID_AD7785,
        ID_AD7792,
        ID_AD7793,
        ID_AD7794,
        ID_AD7795,
        ID_AD7796,
        ID_AD7797,
        ID_AD7798,
        ID_AD7799,
};

static struct ad7793_state *ad_sigma_delta_to_ad7793(struct ad_sigma_delta *sd)
{
        return container_of(sd, struct ad7793_state, sd);
}

static int ad7793_set_channel(struct ad_sigma_delta *sd, unsigned int channel)
{
        struct ad7793_state *st = ad_sigma_delta_to_ad7793(sd);

        st->conf &= ~AD7793_CONF_CHAN_MASK;
        st->conf |= AD7793_CONF_CHAN(channel);

        return ad_sd_write_reg(&st->sd, AD7793_REG_CONF, 2, st->conf);
}

static int ad7793_set_mode(struct ad_sigma_delta *sd,
                           enum ad_sigma_delta_mode mode)
{
        struct ad7793_state *st = ad_sigma_delta_to_ad7793(sd);

        st->mode &= ~AD7793_MODE_SEL_MASK;
        st->mode |= AD7793_MODE_SEL(mode);

        return ad_sd_write_reg(&st->sd, AD7793_REG_MODE, 2, st->mode);
}

static const struct ad_sigma_delta_info ad7793_sigma_delta_info = {
        .set_channel = ad7793_set_channel,
        .set_mode = ad7793_set_mode,
        .has_registers = true,
        .addr_shift = 3,
        .read_mask = BIT(6),
        .irq_flags = IRQF_TRIGGER_FALLING,
        .num_resetclks = 32,
};

static const struct ad_sd_calib_data ad7793_calib_arr[6] = {
        {AD7793_MODE_CAL_INT_ZERO, AD7793_CH_AIN1P_AIN1M},
        {AD7793_MODE_CAL_INT_FULL, AD7793_CH_AIN1P_AIN1M},
        {AD7793_MODE_CAL_INT_ZERO, AD7793_CH_AIN2P_AIN2M},
        {AD7793_MODE_CAL_INT_FULL, AD7793_CH_AIN2P_AIN2M},
        {AD7793_MODE_CAL_INT_ZERO, AD7793_CH_AIN3P_AIN3M},
        {AD7793_MODE_CAL_INT_FULL, AD7793_CH_AIN3P_AIN3M}
};

static int ad7793_calibrate_all(struct ad7793_state *st)
{
        return ad_sd_calibrate_all(&st->sd, ad7793_calib_arr,
                                   ARRAY_SIZE(ad7793_calib_arr));
}

static int ad7793_check_platform_data(struct ad7793_state *st,
        const struct ad7793_platform_data *pdata)
{
        if ((pdata->current_source_direction == AD7793_IEXEC1_IEXEC2_IOUT1 ||
                pdata->current_source_direction == AD7793_IEXEC1_IEXEC2_IOUT2) &&
                ((pdata->exitation_current != AD7793_IX_10uA) &&
                (pdata->exitation_current != AD7793_IX_210uA)))
                return -EINVAL;

        if (!(st->chip_info->flags & AD7793_FLAG_HAS_CLKSEL) &&
                pdata->clock_src != AD7793_CLK_SRC_INT)
                return -EINVAL;

        if (!(st->chip_info->flags & AD7793_FLAG_HAS_REFSEL) &&
                pdata->refsel != AD7793_REFSEL_REFIN1)
                return -EINVAL;

        if (!(st->chip_info->flags & AD7793_FLAG_HAS_VBIAS) &&
                pdata->bias_voltage != AD7793_BIAS_VOLTAGE_DISABLED)
                return -EINVAL;

        if (!(st->chip_info->flags & AD7793_HAS_EXITATION_CURRENT) &&
                pdata->exitation_current != AD7793_IX_DISABLED)
                return -EINVAL;

        return 0;
}

static int ad7793_setup(struct iio_dev *indio_dev,
        const struct ad7793_platform_data *pdata,
        unsigned int vref_mv)
{
        struct ad7793_state *st = iio_priv(indio_dev);
        int i, ret;
        unsigned long long scale_uv;
        u32 id;

        ret = ad7793_check_platform_data(st, pdata);
        if (ret)
                return ret;

        /* reset the serial interface */
        ret = ad_sd_reset(&st->sd);
        if (ret < 0)
                goto out;
        usleep_range(500, 2000); /* Wait for at least 500us */

        /* write/read test for device presence */
        ret = ad_sd_read_reg(&st->sd, AD7793_REG_ID, 1, &id);
        if (ret)
                goto out;

        id &= AD7793_ID_MASK;

        if (id != st->chip_info->id) {
                ret = -ENODEV;
                dev_err(&st->sd.spi->dev, "device ID query failed\n");
                goto out;
        }

        st->mode = AD7793_MODE_RATE(1);
        st->conf = 0;

        if (st->chip_info->flags & AD7793_FLAG_HAS_CLKSEL)
                st->mode |= AD7793_MODE_CLKSRC(pdata->clock_src);
        if (st->chip_info->flags & AD7793_FLAG_HAS_REFSEL)
                st->conf |= AD7793_CONF_REFSEL(pdata->refsel);
        if (st->chip_info->flags & AD7793_FLAG_HAS_VBIAS)
                st->conf |= AD7793_CONF_VBIAS(pdata->bias_voltage);
        if (pdata->buffered || !(st->chip_info->flags & AD7793_FLAG_HAS_BUFFER))
                st->conf |= AD7793_CONF_BUF;
        if (pdata->boost_enable &&
                (st->chip_info->flags & AD7793_FLAG_HAS_VBIAS))
                st->conf |= AD7793_CONF_BOOST;
        if (pdata->burnout_current)
                st->conf |= AD7793_CONF_BO_EN;
        if (pdata->unipolar)
                st->conf |= AD7793_CONF_UNIPOLAR;

        if (!(st->chip_info->flags & AD7793_FLAG_HAS_GAIN))
                st->conf |= AD7793_CONF_GAIN(7);

        ret = ad7793_set_mode(&st->sd, AD_SD_MODE_IDLE);
        if (ret)
                goto out;

        ret = ad7793_set_channel(&st->sd, 0);
        if (ret)
                goto out;

        if (st->chip_info->flags & AD7793_HAS_EXITATION_CURRENT) {
                ret = ad_sd_write_reg(&st->sd, AD7793_REG_IO, 1,
                                pdata->exitation_current |
                                (pdata->current_source_direction << 2));
                if (ret)
                        goto out;
        }

        ret = ad7793_calibrate_all(st);
        if (ret)
                goto out;

        /* Populate available ADC input ranges */
        for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++) {
                scale_uv = ((u64)vref_mv * 100000000)
                        >> (st->chip_info->channels[0].scan_type.realbits -
                        (!!(st->conf & AD7793_CONF_UNIPOLAR) ? 0 : 1));
                scale_uv >>= i;

                st->scale_avail[i][1] = do_div(scale_uv, 100000000) * 10;
                st->scale_avail[i][0] = scale_uv;
        }

        return 0;
out:
        dev_err(&st->sd.spi->dev, "setup failed\n");
        return ret;
}

static const u16 ad7793_sample_freq_avail[16] = {0, 470, 242, 123, 62, 50, 39,
                                        33, 19, 17, 16, 12, 10, 8, 6, 4};

static const u16 ad7797_sample_freq_avail[16] = {0, 0, 0, 123, 62, 50, 0,
                                        33, 0, 17, 16, 12, 10, 8, 6, 4};

static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
        "470 242 123 62 50 39 33 19 17 16 12 10 8 6 4");

static IIO_CONST_ATTR_NAMED(sampling_frequency_available_ad7797,
        sampling_frequency_available, "123 62 50 33 17 16 12 10 8 6 4");

static int ad7793_read_avail(struct iio_dev *indio_dev,
                             struct iio_chan_spec const *chan,
                             const int **vals, int *type, int *length,
                             long mask)
{
        struct ad7793_state *st = iio_priv(indio_dev);

        switch (mask) {
        case IIO_CHAN_INFO_SCALE:
                *vals = (int *)st->scale_avail;
                *type = IIO_VAL_INT_PLUS_NANO;
                /* Values are stored in a 2D matrix  */
                *length = ARRAY_SIZE(st->scale_avail) * 2;

                return IIO_AVAIL_LIST;
        default:
                return -EINVAL;
        }
}

static struct attribute *ad7793_attributes[] = {
        &iio_const_attr_sampling_frequency_available.dev_attr.attr,
        NULL
};

static const struct attribute_group ad7793_attribute_group = {
        .attrs = ad7793_attributes,
};

static struct attribute *ad7797_attributes[] = {
        &iio_const_attr_sampling_frequency_available_ad7797.dev_attr.attr,
        NULL
};

static const struct attribute_group ad7797_attribute_group = {
        .attrs = ad7797_attributes,
};

static int ad7793_read_raw(struct iio_dev *indio_dev,
                           struct iio_chan_spec const *chan,
                           int *val,
                           int *val2,
                           long m)
{
        struct ad7793_state *st = iio_priv(indio_dev);
        int ret;
        unsigned long long scale_uv;
        bool unipolar = !!(st->conf & AD7793_CONF_UNIPOLAR);

        switch (m) {
        case IIO_CHAN_INFO_RAW:
                ret = ad_sigma_delta_single_conversion(indio_dev, chan, val);
                if (ret < 0)
                        return ret;

                return IIO_VAL_INT;

        case IIO_CHAN_INFO_SCALE:
                switch (chan->type) {
                case IIO_VOLTAGE:
                        if (chan->differential) {
                                *val = st->
                                        scale_avail[(st->conf >> 8) & 0x7][0];
                                *val2 = st->
                                        scale_avail[(st->conf >> 8) & 0x7][1];
                                return IIO_VAL_INT_PLUS_NANO;
                        }
                        /* 1170mV / 2^23 * 6 */
                        scale_uv = (1170ULL * 1000000000ULL * 6ULL);
                        break;
                case IIO_TEMP:
                                /* 1170mV / 0.81 mV/C / 2^23 */
                                scale_uv = 1444444444444444ULL;
                        break;
                default:
                        return -EINVAL;
                }

                scale_uv >>= (chan->scan_type.realbits - (unipolar ? 0 : 1));
                *val = 0;
                *val2 = scale_uv;
                return IIO_VAL_INT_PLUS_NANO;
        case IIO_CHAN_INFO_OFFSET:
                if (!unipolar)
                        *val = -(1 << (chan->scan_type.realbits - 1));
                else
                        *val = 0;

                /* Kelvin to Celsius */
                if (chan->type == IIO_TEMP) {
                        unsigned long long offset;
                        unsigned int shift;

                        shift = chan->scan_type.realbits - (unipolar ? 0 : 1);
                        offset = 273ULL << shift;
                        do_div(offset, 1444);
                        *val -= offset;
                }
                return IIO_VAL_INT;
        case IIO_CHAN_INFO_SAMP_FREQ:
                *val = st->chip_info
                               ->sample_freq_avail[AD7793_MODE_RATE(st->mode)];
                return IIO_VAL_INT;
        }
        return -EINVAL;
}

static int __ad7793_write_raw(struct iio_dev *indio_dev,
                              struct iio_chan_spec const *chan,
                              int val, int val2, long mask)
{
        struct ad7793_state *st = iio_priv(indio_dev);
        int i;
        unsigned int tmp;

        switch (mask) {
        case IIO_CHAN_INFO_SCALE:
                for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++) {
                        if (val2 != st->scale_avail[i][1])
                                continue;

                        tmp = st->conf;
                        st->conf &= ~AD7793_CONF_GAIN(-1);
                        st->conf |= AD7793_CONF_GAIN(i);

                        if (tmp == st->conf)
                                return 0;

                        ad_sd_write_reg(&st->sd, AD7793_REG_CONF,
                                        sizeof(st->conf), st->conf);
                        ad7793_calibrate_all(st);

                        return 0;
                }
                return -EINVAL;
        case IIO_CHAN_INFO_SAMP_FREQ:
                if (!val)
                        return -EINVAL;

                for (i = 0; i < 16; i++)
                        if (val == st->chip_info->sample_freq_avail[i])
                                break;

                if (i == 16)
                        return -EINVAL;

                st->mode &= ~AD7793_MODE_RATE(-1);
                st->mode |= AD7793_MODE_RATE(i);
                ad_sd_write_reg(&st->sd, AD7793_REG_MODE, sizeof(st->mode),
                                st->mode);
                return 0;
        default:
                return -EINVAL;
        }
}

static int ad7793_write_raw(struct iio_dev *indio_dev,
                            struct iio_chan_spec const *chan,
                            int val, int val2, long mask)
{
        int ret;

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

        ret = __ad7793_write_raw(indio_dev, chan, val, val2, mask);

        iio_device_release_direct(indio_dev);

        return ret;
}

static int ad7793_write_raw_get_fmt(struct iio_dev *indio_dev,
                               struct iio_chan_spec const *chan,
                               long mask)
{
        return IIO_VAL_INT_PLUS_NANO;
}

static const struct iio_info ad7793_info = {
        .read_raw = &ad7793_read_raw,
        .write_raw = &ad7793_write_raw,
        .write_raw_get_fmt = &ad7793_write_raw_get_fmt,
        .read_avail = ad7793_read_avail,
        .attrs = &ad7793_attribute_group,
        .validate_trigger = ad_sd_validate_trigger,
};

static const struct iio_info ad7797_info = {
        .read_raw = &ad7793_read_raw,
        .write_raw = &ad7793_write_raw,
        .write_raw_get_fmt = &ad7793_write_raw_get_fmt,
        .attrs = &ad7797_attribute_group,
        .validate_trigger = ad_sd_validate_trigger,
};

#define __AD7793_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
        _storagebits, _shift, _extend_name, _type, _mask_type_av, _mask_all) \
        { \
                .type = (_type), \
                .differential = (_channel2 == -1 ? 0 : 1), \
                .indexed = 1, \
                .channel = (_channel1), \
                .channel2 = (_channel2), \
                .address = (_address), \
                .extend_name = (_extend_name), \
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
                        BIT(IIO_CHAN_INFO_OFFSET), \
                .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
                .info_mask_shared_by_type_available = (_mask_type_av), \
                .info_mask_shared_by_all = _mask_all, \
                .scan_index = (_si), \
                .scan_type = { \
                        .sign = 'u', \
                        .realbits = (_bits), \
                        .storagebits = (_storagebits), \
                        .shift = (_shift), \
                        .endianness = IIO_BE, \
                }, \
        }

#define AD7793_DIFF_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
        _storagebits, _shift) \
        __AD7793_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
                _storagebits, _shift, NULL, IIO_VOLTAGE, \
                BIT(IIO_CHAN_INFO_SCALE), \
                BIT(IIO_CHAN_INFO_SAMP_FREQ))

#define AD7793_SHORTED_CHANNEL(_si, _channel, _address, _bits, \
        _storagebits, _shift) \
        __AD7793_CHANNEL(_si, _channel, _channel, _address, _bits, \
                _storagebits, _shift, "shorted", IIO_VOLTAGE, \
                BIT(IIO_CHAN_INFO_SCALE), \
                BIT(IIO_CHAN_INFO_SAMP_FREQ))

#define AD7793_TEMP_CHANNEL(_si, _address, _bits, _storagebits, _shift) \
        __AD7793_CHANNEL(_si, 0, -1, _address, _bits, \
                _storagebits, _shift, NULL, IIO_TEMP, \
                0, \
                BIT(IIO_CHAN_INFO_SAMP_FREQ))

#define AD7793_SUPPLY_CHANNEL(_si, _channel, _address, _bits, _storagebits, \
        _shift) \
        __AD7793_CHANNEL(_si, _channel, -1, _address, _bits, \
                _storagebits, _shift, "supply", IIO_VOLTAGE, \
                0, \
                BIT(IIO_CHAN_INFO_SAMP_FREQ))

#define AD7797_DIFF_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
        _storagebits, _shift) \
        __AD7793_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
                _storagebits, _shift, NULL, IIO_VOLTAGE, \
                0, \
                BIT(IIO_CHAN_INFO_SAMP_FREQ))

#define AD7797_SHORTED_CHANNEL(_si, _channel, _address, _bits, \
        _storagebits, _shift) \
        __AD7793_CHANNEL(_si, _channel, _channel, _address, _bits, \
                _storagebits, _shift, "shorted", IIO_VOLTAGE, \
                0, \
                BIT(IIO_CHAN_INFO_SAMP_FREQ))

#define DECLARE_AD7793_CHANNELS(_name, _b, _sb, _s) \
const struct iio_chan_spec _name##_channels[] = { \
        AD7793_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), (_s)), \
        AD7793_DIFF_CHANNEL(1, 1, 1, AD7793_CH_AIN2P_AIN2M, (_b), (_sb), (_s)), \
        AD7793_DIFF_CHANNEL(2, 2, 2, AD7793_CH_AIN3P_AIN3M, (_b), (_sb), (_s)), \
        AD7793_SHORTED_CHANNEL(3, 0, AD7793_CH_AIN1M_AIN1M, (_b), (_sb), (_s)), \
        AD7793_TEMP_CHANNEL(4, AD7793_CH_TEMP, (_b), (_sb), (_s)), \
        AD7793_SUPPLY_CHANNEL(5, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), (_s)), \
        IIO_CHAN_SOFT_TIMESTAMP(6), \
}

#define DECLARE_AD7795_CHANNELS(_name, _b, _sb) \
const struct iio_chan_spec _name##_channels[] = { \
        AD7793_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), 0), \
        AD7793_DIFF_CHANNEL(1, 1, 1, AD7793_CH_AIN2P_AIN2M, (_b), (_sb), 0), \
        AD7793_DIFF_CHANNEL(2, 2, 2, AD7793_CH_AIN3P_AIN3M, (_b), (_sb), 0), \
        AD7793_DIFF_CHANNEL(3, 3, 3, AD7795_CH_AIN4P_AIN4M, (_b), (_sb), 0), \
        AD7793_DIFF_CHANNEL(4, 4, 4, AD7795_CH_AIN5P_AIN5M, (_b), (_sb), 0), \
        AD7793_DIFF_CHANNEL(5, 5, 5, AD7795_CH_AIN6P_AIN6M, (_b), (_sb), 0), \
        AD7793_SHORTED_CHANNEL(6, 0, AD7795_CH_AIN1M_AIN1M, (_b), (_sb), 0), \
        AD7793_TEMP_CHANNEL(7, AD7793_CH_TEMP, (_b), (_sb), 0), \
        AD7793_SUPPLY_CHANNEL(8, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), 0), \
        IIO_CHAN_SOFT_TIMESTAMP(9), \
}

#define DECLARE_AD7797_CHANNELS(_name, _b, _sb) \
const struct iio_chan_spec _name##_channels[] = { \
        AD7797_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), 0), \
        AD7797_SHORTED_CHANNEL(1, 0, AD7793_CH_AIN1M_AIN1M, (_b), (_sb), 0), \
        AD7793_TEMP_CHANNEL(2, AD7793_CH_TEMP, (_b), (_sb), 0), \
        AD7793_SUPPLY_CHANNEL(3, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), 0), \
        IIO_CHAN_SOFT_TIMESTAMP(4), \
}

#define DECLARE_AD7799_CHANNELS(_name, _b, _sb) \
const struct iio_chan_spec _name##_channels[] = { \
        AD7793_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), 0), \
        AD7793_DIFF_CHANNEL(1, 1, 1, AD7793_CH_AIN2P_AIN2M, (_b), (_sb), 0), \
        AD7793_DIFF_CHANNEL(2, 2, 2, AD7793_CH_AIN3P_AIN3M, (_b), (_sb), 0), \
        AD7793_SHORTED_CHANNEL(3, 0, AD7793_CH_AIN1M_AIN1M, (_b), (_sb), 0), \
        AD7793_SUPPLY_CHANNEL(4, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), 0), \
        IIO_CHAN_SOFT_TIMESTAMP(5), \
}

static DECLARE_AD7793_CHANNELS(ad7785, 20, 32, 4);
static DECLARE_AD7793_CHANNELS(ad7792, 16, 32, 0);
static DECLARE_AD7793_CHANNELS(ad7793, 24, 32, 0);
static DECLARE_AD7795_CHANNELS(ad7794, 16, 32);
static DECLARE_AD7795_CHANNELS(ad7795, 24, 32);
static DECLARE_AD7797_CHANNELS(ad7796, 16, 16);
static DECLARE_AD7797_CHANNELS(ad7797, 24, 32);
static DECLARE_AD7799_CHANNELS(ad7798, 16, 16);
static DECLARE_AD7799_CHANNELS(ad7799, 24, 32);

static const struct ad7793_chip_info ad7793_chip_info_tbl[] = {
        [ID_AD7785] = {
                .id = AD7785_ID,
                .channels = ad7785_channels,
                .num_channels = ARRAY_SIZE(ad7785_channels),
                .iio_info = &ad7793_info,
                .sample_freq_avail = ad7793_sample_freq_avail,
                .flags = AD7793_FLAG_HAS_CLKSEL |
                        AD7793_FLAG_HAS_REFSEL |
                        AD7793_FLAG_HAS_VBIAS |
                        AD7793_HAS_EXITATION_CURRENT |
                        AD7793_FLAG_HAS_GAIN |
                        AD7793_FLAG_HAS_BUFFER,
        },
        [ID_AD7792] = {
                .id = AD7792_ID,
                .channels = ad7792_channels,
                .num_channels = ARRAY_SIZE(ad7792_channels),
                .iio_info = &ad7793_info,
                .sample_freq_avail = ad7793_sample_freq_avail,
                .flags = AD7793_FLAG_HAS_CLKSEL |
                        AD7793_FLAG_HAS_REFSEL |
                        AD7793_FLAG_HAS_VBIAS |
                        AD7793_HAS_EXITATION_CURRENT |
                        AD7793_FLAG_HAS_GAIN |
                        AD7793_FLAG_HAS_BUFFER,
        },
        [ID_AD7793] = {
                .id = AD7793_ID,
                .channels = ad7793_channels,
                .num_channels = ARRAY_SIZE(ad7793_channels),
                .iio_info = &ad7793_info,
                .sample_freq_avail = ad7793_sample_freq_avail,
                .flags = AD7793_FLAG_HAS_CLKSEL |
                        AD7793_FLAG_HAS_REFSEL |
                        AD7793_FLAG_HAS_VBIAS |
                        AD7793_HAS_EXITATION_CURRENT |
                        AD7793_FLAG_HAS_GAIN |
                        AD7793_FLAG_HAS_BUFFER,
        },
        [ID_AD7794] = {
                .id = AD7794_ID,
                .channels = ad7794_channels,
                .num_channels = ARRAY_SIZE(ad7794_channels),
                .iio_info = &ad7793_info,
                .sample_freq_avail = ad7793_sample_freq_avail,
                .flags = AD7793_FLAG_HAS_CLKSEL |
                        AD7793_FLAG_HAS_REFSEL |
                        AD7793_FLAG_HAS_VBIAS |
                        AD7793_HAS_EXITATION_CURRENT |
                        AD7793_FLAG_HAS_GAIN |
                        AD7793_FLAG_HAS_BUFFER,
        },
        [ID_AD7795] = {
                .id = AD7795_ID,
                .channels = ad7795_channels,
                .num_channels = ARRAY_SIZE(ad7795_channels),
                .iio_info = &ad7793_info,
                .sample_freq_avail = ad7793_sample_freq_avail,
                .flags = AD7793_FLAG_HAS_CLKSEL |
                        AD7793_FLAG_HAS_REFSEL |
                        AD7793_FLAG_HAS_VBIAS |
                        AD7793_HAS_EXITATION_CURRENT |
                        AD7793_FLAG_HAS_GAIN |
                        AD7793_FLAG_HAS_BUFFER,
        },
        [ID_AD7796] = {
                .id = AD7796_ID,
                .channels = ad7796_channels,
                .num_channels = ARRAY_SIZE(ad7796_channels),
                .iio_info = &ad7797_info,
                .sample_freq_avail = ad7797_sample_freq_avail,
                .flags = AD7793_FLAG_HAS_CLKSEL,
        },
        [ID_AD7797] = {
                .id = AD7797_ID,
                .channels = ad7797_channels,
                .num_channels = ARRAY_SIZE(ad7797_channels),
                .iio_info = &ad7797_info,
                .sample_freq_avail = ad7797_sample_freq_avail,
                .flags = AD7793_FLAG_HAS_CLKSEL,
        },
        [ID_AD7798] = {
                .id = AD7798_ID,
                .channels = ad7798_channels,
                .num_channels = ARRAY_SIZE(ad7798_channels),
                .iio_info = &ad7793_info,
                .sample_freq_avail = ad7793_sample_freq_avail,
                .flags = AD7793_FLAG_HAS_GAIN |
                        AD7793_FLAG_HAS_BUFFER,
        },
        [ID_AD7799] = {
                .id = AD7799_ID,
                .channels = ad7799_channels,
                .num_channels = ARRAY_SIZE(ad7799_channels),
                .iio_info = &ad7793_info,
                .sample_freq_avail = ad7793_sample_freq_avail,
                .flags = AD7793_FLAG_HAS_GAIN |
                        AD7793_FLAG_HAS_BUFFER,
        },
};

static int ad7793_probe(struct spi_device *spi)
{
        const struct ad7793_platform_data *pdata = dev_get_platdata(&spi->dev);
        struct ad7793_state *st;
        struct iio_dev *indio_dev;
        int ret, vref_mv = 0;

        if (!pdata) {
                dev_err(&spi->dev, "no platform data?\n");
                return -ENODEV;
        }

        if (!spi->irq) {
                dev_err(&spi->dev, "no IRQ?\n");
                return -ENODEV;
        }

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

        st = iio_priv(indio_dev);

        ad_sd_init(&st->sd, indio_dev, spi, &ad7793_sigma_delta_info);

        if (pdata->refsel != AD7793_REFSEL_INTERNAL) {
                ret = devm_regulator_get_enable_read_voltage(&spi->dev, "refin");
                if (ret < 0)
                        return ret;

                vref_mv = ret / 1000;
        } else {
                vref_mv = 1170; /* Build-in ref */
        }

        st->chip_info =
                &ad7793_chip_info_tbl[spi_get_device_id(spi)->driver_data];

        indio_dev->name = spi_get_device_id(spi)->name;
        indio_dev->modes = INDIO_DIRECT_MODE;
        indio_dev->channels = st->chip_info->channels;
        indio_dev->num_channels = st->chip_info->num_channels;
        indio_dev->info = st->chip_info->iio_info;

        ret = devm_ad_sd_setup_buffer_and_trigger(&spi->dev, indio_dev);
        if (ret)
                return ret;

        ret = ad7793_setup(indio_dev, pdata, vref_mv);
        if (ret)
                return ret;

        return devm_iio_device_register(&spi->dev, indio_dev);
}

static const struct spi_device_id ad7793_id[] = {
        { "ad7785", ID_AD7785 },
        { "ad7792", ID_AD7792 },
        { "ad7793", ID_AD7793 },
        { "ad7794", ID_AD7794 },
        { "ad7795", ID_AD7795 },
        { "ad7796", ID_AD7796 },
        { "ad7797", ID_AD7797 },
        { "ad7798", ID_AD7798 },
        { "ad7799", ID_AD7799 },
        { }
};
MODULE_DEVICE_TABLE(spi, ad7793_id);

static struct spi_driver ad7793_driver = {
        .driver = {
                .name   = "ad7793",
        },
        .probe          = ad7793_probe,
        .id_table       = ad7793_id,
};
module_spi_driver(ad7793_driver);

MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD7793 and similar ADCs");
MODULE_LICENSE("GPL v2");
MODULE_IMPORT_NS("IIO_AD_SIGMA_DELTA");