// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * ADS7138 - Texas Instruments Analog-to-Digital Converter
 */

#include <linux/bitfield.h>
#include <linux/cleanup.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>
#include <linux/regulator/consumer.h>
#include <linux/unaligned.h>

#include <linux/iio/events.h>
#include <linux/iio/iio.h>
#include <linux/iio/types.h>

/*
 * Always assume 16 bits resolution as HW registers are aligned like that and
 * with enabled oversampling/averaging it actually corresponds to 16 bits.
 */
#define ADS7138_RES_BITS                16

/* ADS7138 operation codes */
#define ADS7138_OPCODE_SINGLE_WRITE     0x08
#define ADS7138_OPCODE_SET_BIT          0x18
#define ADS7138_OPCODE_CLEAR_BIT        0x20
#define ADS7138_OPCODE_BLOCK_WRITE      0x28
#define ADS7138_OPCODE_BLOCK_READ       0x30

/* ADS7138 registers */
#define ADS7138_REG_GENERAL_CFG         0x01
#define ADS7138_REG_OSR_CFG             0x03
#define ADS7138_REG_OPMODE_CFG          0x04
#define ADS7138_REG_SEQUENCE_CFG        0x10
#define ADS7138_REG_AUTO_SEQ_CH_SEL     0x12
#define ADS7138_REG_ALERT_CH_SEL        0x14
#define ADS7138_REG_EVENT_FLAG          0x18
#define ADS7138_REG_EVENT_HIGH_FLAG     0x1A
#define ADS7138_REG_EVENT_LOW_FLAG      0x1C
#define ADS7138_REG_HIGH_TH_HYS_CH(x)   ((x) * 4 + 0x20)
#define ADS7138_REG_LOW_TH_CNT_CH(x)    ((x) * 4 + 0x22)
#define ADS7138_REG_MAX_LSB_CH(x)       ((x) * 2 + 0x60)
#define ADS7138_REG_MIN_LSB_CH(x)       ((x) * 2 + 0x80)
#define ADS7138_REG_RECENT_LSB_CH(x)    ((x) * 2 + 0xA0)

#define ADS7138_GENERAL_CFG_RST         BIT(0)
#define ADS7138_GENERAL_CFG_DWC_EN      BIT(4)
#define ADS7138_GENERAL_CFG_STATS_EN    BIT(5)
#define ADS7138_OSR_CFG_MASK            GENMASK(2, 0)
#define ADS7138_OPMODE_CFG_CONV_MODE    BIT(5)
#define ADS7138_OPMODE_CFG_FREQ_MASK    GENMASK(4, 0)
#define ADS7138_SEQUENCE_CFG_SEQ_MODE   BIT(0)
#define ADS7138_SEQUENCE_CFG_SEQ_START  BIT(4)
#define ADS7138_THRESHOLD_LSB_MASK      GENMASK(7, 4)

enum ads7138_modes {
        ADS7138_MODE_MANUAL,
        ADS7138_MODE_AUTO,
};

struct ads7138_chip_data {
        const char *name;
        const int channel_num;
};

struct ads7138_data {
        /* Protects RMW access to the I2C interface */
        struct mutex lock;
        struct i2c_client *client;
        struct regulator *vref_regu;
        const struct ads7138_chip_data *chip_data;
};

/*
 * 2D array of available sampling frequencies and the corresponding register
 * values. Structured like this to be easily usable in read_avail function.
 */
static const int ads7138_samp_freqs_bits[2][26] = {
        {
                163, 244, 326, 488, 651, 977, 1302, 1953,
                2604, 3906, 5208, 7813, 10417, 15625, 20833, 31250,
                41667, 62500, 83333, 125000, 166667, 250000, 333333, 500000,
                666667, 1000000
        }, {
                0x1f, 0x1e, 0x1d, 0x1c, 0x1b, 0x1a, 0x19, 0x18,
                0x17, 0x16, 0x15, 0x14, 0x13, 0x12, 0x11, 0x10,
                /* Here is a hole, due to duplicate frequencies */
                0x09, 0x08, 0x07, 0x06, 0x05, 0x04, 0x03, 0x02,
                0x01, 0x00
        }
};

static const int ads7138_oversampling_ratios[] = {
        1, 2, 4, 8, 16, 32, 64, 128
};

static int ads7138_i2c_write_block(const struct i2c_client *client, u8 reg,
                                   u8 *values, u8 length)
{
        int ret;
        int len = length + 2; /* "+ 2" for OPCODE and reg */

        u8 *buf __free(kfree) = kmalloc(len, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        buf[0] = ADS7138_OPCODE_BLOCK_WRITE;
        buf[1] = reg;
        memcpy(&buf[2], values, length);

        ret = i2c_master_send(client, buf, len);
        if (ret < 0)
                return ret;
        if (ret != len)
                return -EIO;

        return 0;
}

static int ads7138_i2c_write_with_opcode(const struct i2c_client *client,
                                         u8 reg, u8 regval, u8 opcode)
{
        u8 buf[3] = { opcode, reg, regval };
        int ret;

        ret = i2c_master_send(client, buf, ARRAY_SIZE(buf));
        if (ret < 0)
                return ret;
        if (ret != ARRAY_SIZE(buf))
                return -EIO;

        return 0;
}

static int ads7138_i2c_write(const struct i2c_client *client, u8 reg, u8 value)
{
        return ads7138_i2c_write_with_opcode(client, reg, value,
                                             ADS7138_OPCODE_SINGLE_WRITE);
}

static int ads7138_i2c_set_bit(const struct i2c_client *client, u8 reg, u8 bits)
{
        return ads7138_i2c_write_with_opcode(client, reg, bits,
                                             ADS7138_OPCODE_SET_BIT);
}

static int ads7138_i2c_clear_bit(const struct i2c_client *client, u8 reg, u8 bits)
{
        return ads7138_i2c_write_with_opcode(client, reg, bits,
                                             ADS7138_OPCODE_CLEAR_BIT);
}

static int ads7138_i2c_read_block(const struct i2c_client *client, u8 reg,
                                  u8 *out_values, u8 length)
{
        u8 buf[2] = { ADS7138_OPCODE_BLOCK_READ, reg };
        int ret;
        struct i2c_msg msgs[] = {
                {
                        .addr = client->addr,
                        .len = ARRAY_SIZE(buf),
                        .buf = buf,
                },
                {
                        .addr = client->addr,
                        .flags = I2C_M_RD,
                        .len = length,
                        .buf = out_values,
                },
        };

        ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
        if (ret < 0)
                return ret;
        if (ret != ARRAY_SIZE(msgs))
                return -EIO;

        return 0;
}

static int ads7138_i2c_read(const struct i2c_client *client, u8 reg)
{
        u8 value;
        int ret;

        ret = ads7138_i2c_read_block(client, reg, &value, sizeof(value));
        if (ret)
                return ret;
        return value;
}

static int ads7138_freq_to_bits(int freq)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(ads7138_samp_freqs_bits[0]); i++)
                if (freq == ads7138_samp_freqs_bits[0][i])
                        return ads7138_samp_freqs_bits[1][i];

        return -EINVAL;
}

static int ads7138_bits_to_freq(int bits)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(ads7138_samp_freqs_bits[1]); i++)
                if (bits == ads7138_samp_freqs_bits[1][i])
                        return ads7138_samp_freqs_bits[0][i];

        return -EINVAL;
}

static int ads7138_osr_to_bits(int osr)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(ads7138_oversampling_ratios); i++)
                if (osr == ads7138_oversampling_ratios[i])
                        return i;

        return -EINVAL;
}

static int ads7138_read_raw(struct iio_dev *indio_dev,
                            struct iio_chan_spec const *chan, int *val,
                            int *val2, long mask)
{
        struct ads7138_data *data = iio_priv(indio_dev);
        int ret, vref, bits;
        u8 values[2];

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                ret = ads7138_i2c_read_block(data->client,
                                             ADS7138_REG_RECENT_LSB_CH(chan->channel),
                                             values, ARRAY_SIZE(values));
                if (ret)
                        return ret;

                *val = get_unaligned_le16(values);
                return IIO_VAL_INT;
        case IIO_CHAN_INFO_PEAK:
                ret = ads7138_i2c_read_block(data->client,
                                             ADS7138_REG_MAX_LSB_CH(chan->channel),
                                             values, ARRAY_SIZE(values));
                if (ret)
                        return ret;

                *val = get_unaligned_le16(values);
                return IIO_VAL_INT;
        case IIO_CHAN_INFO_TROUGH:
                ret = ads7138_i2c_read_block(data->client,
                                             ADS7138_REG_MIN_LSB_CH(chan->channel),
                                             values, ARRAY_SIZE(values));
                if (ret)
                        return ret;

                *val = get_unaligned_le16(values);
                return IIO_VAL_INT;
        case IIO_CHAN_INFO_SAMP_FREQ:
                ret = ads7138_i2c_read(data->client, ADS7138_REG_OPMODE_CFG);
                if (ret < 0)
                        return ret;

                bits = FIELD_GET(ADS7138_OPMODE_CFG_FREQ_MASK, ret);
                *val = ads7138_bits_to_freq(bits);
                return IIO_VAL_INT;
        case IIO_CHAN_INFO_SCALE:
                vref = regulator_get_voltage(data->vref_regu);
                if (vref < 0)
                        return vref;
                *val = vref / 1000;
                *val2 = ADS7138_RES_BITS;
                return IIO_VAL_FRACTIONAL_LOG2;
        case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
                ret = ads7138_i2c_read(data->client, ADS7138_REG_OSR_CFG);
                if (ret < 0)
                        return ret;

                bits = FIELD_GET(ADS7138_OSR_CFG_MASK, ret);
                *val = ads7138_oversampling_ratios[bits];
                return IIO_VAL_INT;
        default:
                return -EINVAL;
        }
}

static int ads7138_write_raw(struct iio_dev *indio_dev,
                             struct iio_chan_spec const *chan, int val,
                             int val2, long mask)
{
        struct ads7138_data *data = iio_priv(indio_dev);
        int bits, ret;
        u8 value;

        switch (mask) {
        case IIO_CHAN_INFO_SAMP_FREQ: {
                bits = ads7138_freq_to_bits(val);
                if (bits < 0)
                        return bits;

                guard(mutex)(&data->lock);
                ret = ads7138_i2c_read(data->client, ADS7138_REG_OPMODE_CFG);
                if (ret < 0)
                        return ret;

                value = ret & ~ADS7138_OPMODE_CFG_FREQ_MASK;
                value |= FIELD_PREP(ADS7138_OPMODE_CFG_FREQ_MASK, bits);
                return ads7138_i2c_write(data->client, ADS7138_REG_OPMODE_CFG,
                                         value);
        }
        case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
                bits = ads7138_osr_to_bits(val);
                if (bits < 0)
                        return bits;

                return ads7138_i2c_write(data->client, ADS7138_REG_OSR_CFG,
                                         bits);
        default:
                return -EINVAL;
        }
}

static int ads7138_read_event(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)
{
        struct ads7138_data *data = iio_priv(indio_dev);
        u8 reg, values[2];
        int ret;

        switch (info) {
        case IIO_EV_INFO_VALUE:
                reg = (dir == IIO_EV_DIR_RISING) ?
                        ADS7138_REG_HIGH_TH_HYS_CH(chan->channel) :
                        ADS7138_REG_LOW_TH_CNT_CH(chan->channel);
                ret = ads7138_i2c_read_block(data->client, reg, values,
                                             ARRAY_SIZE(values));
                if (ret)
                        return ret;

                *val = ((values[1] << 4) | (values[0] >> 4));
                return IIO_VAL_INT;
        case IIO_EV_INFO_HYSTERESIS:
                ret = ads7138_i2c_read(data->client,
                                       ADS7138_REG_HIGH_TH_HYS_CH(chan->channel));
                if (ret < 0)
                        return ret;

                *val = ret & ~ADS7138_THRESHOLD_LSB_MASK;
                return IIO_VAL_INT;
        default:
                return -EINVAL;
        }
}

static int ads7138_write_event(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)
{
        struct ads7138_data *data = iio_priv(indio_dev);
        u8 reg, values[2];
        int ret;

        switch (info) {
        case IIO_EV_INFO_VALUE: {
                if (val >= BIT(12) || val < 0)
                        return -EINVAL;

                reg = (dir == IIO_EV_DIR_RISING) ?
                        ADS7138_REG_HIGH_TH_HYS_CH(chan->channel) :
                        ADS7138_REG_LOW_TH_CNT_CH(chan->channel);

                guard(mutex)(&data->lock);
                ret = ads7138_i2c_read(data->client, reg);
                if (ret < 0)
                        return ret;

                values[0] = ret & ~ADS7138_THRESHOLD_LSB_MASK;
                values[0] |= FIELD_PREP(ADS7138_THRESHOLD_LSB_MASK, val);
                values[1] = (val >> 4);
                return ads7138_i2c_write_block(data->client, reg, values,
                                               ARRAY_SIZE(values));
        }
        case IIO_EV_INFO_HYSTERESIS: {
                if (val >= BIT(4) || val < 0)
                        return -EINVAL;

                reg = ADS7138_REG_HIGH_TH_HYS_CH(chan->channel);

                guard(mutex)(&data->lock);
                ret = ads7138_i2c_read(data->client, reg);
                if (ret < 0)
                        return ret;

                values[0] = val & ~ADS7138_THRESHOLD_LSB_MASK;
                values[0] |= FIELD_PREP(ADS7138_THRESHOLD_LSB_MASK, ret >> 4);
                return ads7138_i2c_write(data->client, reg, values[0]);
        }
        default:
                return -EINVAL;
        }
}

static int ads7138_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 ads7138_data *data = iio_priv(indio_dev);
        int ret;

        if (dir != IIO_EV_DIR_EITHER)
                return -EINVAL;

        ret = ads7138_i2c_read(data->client, ADS7138_REG_ALERT_CH_SEL);
        if (ret < 0)
                return ret;

        return (ret & BIT(chan->channel)) ? 1 : 0;
}

static int ads7138_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 ads7138_data *data = iio_priv(indio_dev);

        if (dir != IIO_EV_DIR_EITHER)
                return -EINVAL;

        if (state)
                return ads7138_i2c_set_bit(data->client,
                                           ADS7138_REG_ALERT_CH_SEL,
                                           BIT(chan->channel));
        else
                return ads7138_i2c_clear_bit(data->client,
                                             ADS7138_REG_ALERT_CH_SEL,
                                             BIT(chan->channel));
}

static int ads7138_read_avail(struct iio_dev *indio_dev,
                              struct iio_chan_spec const *chan,
                              const int **vals, int *type, int *length,
                              long mask)
{
        switch (mask) {
        case IIO_CHAN_INFO_SAMP_FREQ:
                *vals = ads7138_samp_freqs_bits[0];
                *length = ARRAY_SIZE(ads7138_samp_freqs_bits[0]);
                *type = IIO_VAL_INT;

                return IIO_AVAIL_LIST;
        case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
                *vals = ads7138_oversampling_ratios;
                *length = ARRAY_SIZE(ads7138_oversampling_ratios);
                *type = IIO_VAL_INT;

                return IIO_AVAIL_LIST;
        default:
                return -EINVAL;
        }
}

static const struct iio_info ti_ads7138_info = {
        .read_raw = &ads7138_read_raw,
        .read_avail = &ads7138_read_avail,
        .write_raw = &ads7138_write_raw,
        .read_event_value = &ads7138_read_event,
        .write_event_value = &ads7138_write_event,
        .read_event_config = &ads7138_read_event_config,
        .write_event_config = &ads7138_write_event_config,
};

static const struct iio_event_spec ads7138_events[] = {
        {
                .type = IIO_EV_TYPE_THRESH,
                .dir = IIO_EV_DIR_RISING,
                .mask_separate = BIT(IIO_EV_INFO_VALUE)
        }, {
                .type = IIO_EV_TYPE_THRESH,
                .dir = IIO_EV_DIR_FALLING,
                .mask_separate = BIT(IIO_EV_INFO_VALUE),
        }, {
                .type = IIO_EV_TYPE_THRESH,
                .dir = IIO_EV_DIR_EITHER,
                .mask_separate = BIT(IIO_EV_INFO_HYSTERESIS) |
                                 BIT(IIO_EV_INFO_ENABLE),
        },
};

#define ADS7138_V_CHAN(_chan) {                                         \
        .type = IIO_VOLTAGE,                                            \
        .indexed = 1,                                                   \
        .channel = _chan,                                               \
        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |                  \
                              BIT(IIO_CHAN_INFO_PEAK) |                 \
                              BIT(IIO_CHAN_INFO_TROUGH),                \
        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) |      \
                                    BIT(IIO_CHAN_INFO_SCALE) |          \
                                    BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
        .info_mask_shared_by_type_available =                           \
                                BIT(IIO_CHAN_INFO_SAMP_FREQ) |          \
                                BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),  \
        .datasheet_name = "AIN"#_chan,                                  \
        .event_spec = ads7138_events,                                   \
        .num_event_specs = ARRAY_SIZE(ads7138_events),                  \
}

static const struct iio_chan_spec ads7138_channels[] = {
        ADS7138_V_CHAN(0),
        ADS7138_V_CHAN(1),
        ADS7138_V_CHAN(2),
        ADS7138_V_CHAN(3),
        ADS7138_V_CHAN(4),
        ADS7138_V_CHAN(5),
        ADS7138_V_CHAN(6),
        ADS7138_V_CHAN(7),
};

static irqreturn_t ads7138_event_handler(int irq, void *priv)
{
        struct iio_dev *indio_dev = priv;
        struct ads7138_data *data = iio_priv(indio_dev);
        struct device *dev = &data->client->dev;
        u8 i, events_high, events_low;
        u64 code;
        int ret;

        /* Check if interrupt was trigger by us */
        ret = ads7138_i2c_read(data->client, ADS7138_REG_EVENT_FLAG);
        if (ret <= 0)
                return IRQ_NONE;

        ret = ads7138_i2c_read(data->client, ADS7138_REG_EVENT_HIGH_FLAG);
        if (ret < 0) {
                dev_warn(dev, "Failed to read event high flags: %d\n", ret);
                return IRQ_HANDLED;
        }
        events_high = ret;

        ret = ads7138_i2c_read(data->client, ADS7138_REG_EVENT_LOW_FLAG);
        if (ret < 0) {
                dev_warn(dev, "Failed to read event low flags: %d\n", ret);
                return IRQ_HANDLED;
        }
        events_low = ret;

        for (i = 0; i < data->chip_data->channel_num; i++) {
                if (events_high & BIT(i)) {
                        code = IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE, i,
                                                    IIO_EV_TYPE_THRESH,
                                                    IIO_EV_DIR_RISING);
                        iio_push_event(indio_dev, code,
                                       iio_get_time_ns(indio_dev));
                }
                if (events_low & BIT(i)) {
                        code = IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE, i,
                                                    IIO_EV_TYPE_THRESH,
                                                    IIO_EV_DIR_FALLING);
                        iio_push_event(indio_dev, code,
                                       iio_get_time_ns(indio_dev));
                }
        }

        /* Try to clear all interrupt flags */
        ret = ads7138_i2c_write(data->client, ADS7138_REG_EVENT_HIGH_FLAG, 0xFF);
        if (ret)
                dev_warn(dev, "Failed to clear event high flags: %d\n", ret);

        ret = ads7138_i2c_write(data->client, ADS7138_REG_EVENT_LOW_FLAG, 0xFF);
        if (ret)
                dev_warn(dev, "Failed to clear event low flags: %d\n", ret);

        return IRQ_HANDLED;
}

static int ads7138_set_conv_mode(struct ads7138_data *data,
                                 enum ads7138_modes mode)
{
        if (mode == ADS7138_MODE_AUTO)
                return ads7138_i2c_set_bit(data->client, ADS7138_REG_OPMODE_CFG,
                                           ADS7138_OPMODE_CFG_CONV_MODE);
        return ads7138_i2c_clear_bit(data->client, ADS7138_REG_OPMODE_CFG,
                                     ADS7138_OPMODE_CFG_CONV_MODE);
}

static int ads7138_init_hw(struct ads7138_data *data)
{
        struct device *dev = &data->client->dev;
        int ret;

        data->vref_regu = devm_regulator_get(dev, "avdd");
        if (IS_ERR(data->vref_regu))
                return dev_err_probe(dev, PTR_ERR(data->vref_regu),
                                     "Failed to get avdd regulator\n");

        ret = regulator_get_voltage(data->vref_regu);
        if (ret < 0)
                return dev_err_probe(dev, ret, "Failed to get avdd voltage\n");

        /* Reset the chip to get a defined starting configuration */
        ret = ads7138_i2c_set_bit(data->client, ADS7138_REG_GENERAL_CFG,
                                  ADS7138_GENERAL_CFG_RST);
        if (ret)
                return ret;

        ret = ads7138_set_conv_mode(data, ADS7138_MODE_AUTO);
        if (ret)
                return ret;

        /* Enable statistics and digital window comparator */
        ret = ads7138_i2c_set_bit(data->client, ADS7138_REG_GENERAL_CFG,
                                  ADS7138_GENERAL_CFG_STATS_EN |
                                  ADS7138_GENERAL_CFG_DWC_EN);
        if (ret)
                return ret;

        /* Enable all channels for auto sequencing */
        ret = ads7138_i2c_set_bit(data->client, ADS7138_REG_AUTO_SEQ_CH_SEL, 0xFF);
        if (ret)
                return ret;

        /* Set auto sequence mode and start sequencing */
        return ads7138_i2c_set_bit(data->client, ADS7138_REG_SEQUENCE_CFG,
                                   ADS7138_SEQUENCE_CFG_SEQ_START |
                                   ADS7138_SEQUENCE_CFG_SEQ_MODE);
}

static int ads7138_probe(struct i2c_client *client)
{
        struct device *dev = &client->dev;
        struct iio_dev *indio_dev;
        struct ads7138_data *data;
        int ret;

        indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
        if (!indio_dev)
                return -ENOMEM;

        data = iio_priv(indio_dev);
        data->client = client;
        data->chip_data = i2c_get_match_data(client);
        if (!data->chip_data)
                return -ENODEV;

        ret = devm_mutex_init(dev, &data->lock);
        if (ret)
                return ret;

        indio_dev->name = data->chip_data->name;
        indio_dev->modes = INDIO_DIRECT_MODE;
        indio_dev->channels = ads7138_channels;
        indio_dev->num_channels = ARRAY_SIZE(ads7138_channels);
        indio_dev->info = &ti_ads7138_info;

        i2c_set_clientdata(client, indio_dev);

        if (client->irq > 0) {
                ret = devm_request_threaded_irq(dev, client->irq,
                                                NULL, ads7138_event_handler,
                                                IRQF_TRIGGER_LOW |
                                                IRQF_ONESHOT | IRQF_SHARED,
                                                client->name, indio_dev);
                if (ret)
                        return ret;
        }

        ret = ads7138_init_hw(data);
        if (ret)
                return dev_err_probe(dev, ret, "Failed to initialize device\n");

        ret = devm_iio_device_register(dev, indio_dev);
        if (ret)
                return dev_err_probe(dev, ret, "Failed to register iio device\n");

        return 0;
}

static int ads7138_runtime_suspend(struct device *dev)
{
        struct iio_dev *indio_dev = dev_get_drvdata(dev);
        struct ads7138_data *data = iio_priv(indio_dev);

        return ads7138_set_conv_mode(data, ADS7138_MODE_MANUAL);
}

static int ads7138_runtime_resume(struct device *dev)
{
        struct iio_dev *indio_dev = dev_get_drvdata(dev);
        struct ads7138_data *data = iio_priv(indio_dev);

        return ads7138_set_conv_mode(data, ADS7138_MODE_AUTO);
}

static DEFINE_RUNTIME_DEV_PM_OPS(ads7138_pm_ops,
                                 ads7138_runtime_suspend,
                                 ads7138_runtime_resume,
                                 NULL);

static const struct ads7138_chip_data ads7128_data = {
        .name = "ads7128",
        .channel_num = 8,
};

static const struct ads7138_chip_data ads7138_data = {
        .name = "ads7138",
        .channel_num = 8,
};

static const struct of_device_id ads7138_of_match[] = {
        { .compatible = "ti,ads7128", .data = &ads7128_data },
        { .compatible = "ti,ads7138", .data = &ads7138_data },
        { }
};
MODULE_DEVICE_TABLE(of, ads7138_of_match);

static const struct i2c_device_id ads7138_device_ids[] = {
        { "ads7128", (kernel_ulong_t)&ads7128_data },
        { "ads7138", (kernel_ulong_t)&ads7138_data },
        { }
};
MODULE_DEVICE_TABLE(i2c, ads7138_device_ids);

static struct i2c_driver ads7138_driver = {
        .driver = {
                .name = "ads7138",
                .of_match_table = ads7138_of_match,
                .pm = pm_ptr(&ads7138_pm_ops),
        },
        .id_table = ads7138_device_ids,
        .probe = ads7138_probe,
};
module_i2c_driver(ads7138_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Tobias Sperling <tobias.sperling@softing.com>");
MODULE_DESCRIPTION("Driver for TI ADS7138 ADCs");