root/drivers/iio/light/bh1745.c
// SPDX-License-Identifier: GPL-2.0
/*
 * ROHM BH1745 digital colour sensor driver
 *
 * Copyright (C) Mudit Sharma <muditsharma.info@gmail.com>
 *
 * 7-bit I2C slave addresses:
 *  0x38 (ADDR pin low)
 *  0x39 (ADDR pin high)
 */

#include <linux/i2c.h>
#include <linux/mutex.h>
#include <linux/util_macros.h>
#include <linux/iio/events.h>
#include <linux/regmap.h>
#include <linux/bits.h>
#include <linux/bitfield.h>

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/iio-gts-helper.h>

/* BH1745 configuration registers */

/* System control */
#define BH1745_SYS_CTRL 0x40
#define BH1745_SYS_CTRL_SW_RESET BIT(7)
#define BH1745_SYS_CTRL_INTR_RESET BIT(6)
#define BH1745_SYS_CTRL_PART_ID_MASK GENMASK(5, 0)
#define BH1745_PART_ID 0x0B

/* Mode control 1 */
#define BH1745_MODE_CTRL1 0x41
#define BH1745_CTRL1_MEASUREMENT_TIME_MASK GENMASK(2, 0)

/* Mode control 2 */
#define BH1745_MODE_CTRL2 0x42
#define BH1745_CTRL2_RGBC_EN BIT(4)
#define BH1745_CTRL2_ADC_GAIN_MASK GENMASK(1, 0)

/* Interrupt */
#define BH1745_INTR 0x60
#define BH1745_INTR_STATUS BIT(7)
#define BH1745_INTR_SOURCE_MASK GENMASK(3, 2)
#define BH1745_INTR_ENABLE BIT(0)

#define BH1745_PERSISTENCE 0x61

/* Threshold high */
#define BH1745_TH_LSB 0x62
#define BH1745_TH_MSB 0x63

/* Threshold low */
#define BH1745_TL_LSB 0x64
#define BH1745_TL_MSB 0x65

/* BH1745 data output regs */
#define BH1745_RED_LSB 0x50
#define BH1745_RED_MSB 0x51
#define BH1745_GREEN_LSB 0x52
#define BH1745_GREEN_MSB 0x53
#define BH1745_BLUE_LSB 0x54
#define BH1745_BLUE_MSB 0x55
#define BH1745_CLEAR_LSB 0x56
#define BH1745_CLEAR_MSB 0x57

#define BH1745_MANU_ID_REG 0x92

/* From 16x max HW gain and 32x max integration time */
#define BH1745_MAX_GAIN 512

enum bh1745_int_source {
        BH1745_INTR_SOURCE_RED,
        BH1745_INTR_SOURCE_GREEN,
        BH1745_INTR_SOURCE_BLUE,
        BH1745_INTR_SOURCE_CLEAR,
};

enum bh1745_gain {
        BH1745_ADC_GAIN_1X,
        BH1745_ADC_GAIN_2X,
        BH1745_ADC_GAIN_16X,
};

enum bh1745_measurement_time {
        BH1745_MEASUREMENT_TIME_160MS,
        BH1745_MEASUREMENT_TIME_320MS,
        BH1745_MEASUREMENT_TIME_640MS,
        BH1745_MEASUREMENT_TIME_1280MS,
        BH1745_MEASUREMENT_TIME_2560MS,
        BH1745_MEASUREMENT_TIME_5120MS,
};

enum bh1745_presistence_value {
        BH1745_PRESISTENCE_UPDATE_TOGGLE,
        BH1745_PRESISTENCE_UPDATE_EACH_MEASUREMENT,
        BH1745_PRESISTENCE_UPDATE_FOUR_MEASUREMENT,
        BH1745_PRESISTENCE_UPDATE_EIGHT_MEASUREMENT,
};

static const struct iio_gain_sel_pair bh1745_gain[] = {
        GAIN_SCALE_GAIN(1, BH1745_ADC_GAIN_1X),
        GAIN_SCALE_GAIN(2, BH1745_ADC_GAIN_2X),
        GAIN_SCALE_GAIN(16, BH1745_ADC_GAIN_16X),
};

static const struct iio_itime_sel_mul bh1745_itimes[] = {
        GAIN_SCALE_ITIME_US(5120000, BH1745_MEASUREMENT_TIME_5120MS, 32),
        GAIN_SCALE_ITIME_US(2560000, BH1745_MEASUREMENT_TIME_2560MS, 16),
        GAIN_SCALE_ITIME_US(1280000, BH1745_MEASUREMENT_TIME_1280MS, 8),
        GAIN_SCALE_ITIME_US(640000, BH1745_MEASUREMENT_TIME_640MS, 4),
        GAIN_SCALE_ITIME_US(320000, BH1745_MEASUREMENT_TIME_320MS, 2),
        GAIN_SCALE_ITIME_US(160000, BH1745_MEASUREMENT_TIME_160MS, 1),
};

struct bh1745_data {
        /*
         * Lock to prevent device setting update or read before
         * related calculations are completed
         */
        struct mutex lock;
        struct regmap *regmap;
        struct device *dev;
        struct iio_trigger *trig;
        struct iio_gts gts;
};

static const struct regmap_range bh1745_volatile_ranges[] = {
        regmap_reg_range(BH1745_MODE_CTRL2, BH1745_MODE_CTRL2), /* VALID */
        regmap_reg_range(BH1745_RED_LSB, BH1745_CLEAR_MSB), /* Data */
        regmap_reg_range(BH1745_INTR, BH1745_INTR), /* Interrupt */
};

static const struct regmap_access_table bh1745_volatile_regs = {
        .yes_ranges = bh1745_volatile_ranges,
        .n_yes_ranges = ARRAY_SIZE(bh1745_volatile_ranges),
};

static const struct regmap_range bh1745_readable_ranges[] = {
        regmap_reg_range(BH1745_SYS_CTRL, BH1745_MODE_CTRL2),
        regmap_reg_range(BH1745_RED_LSB, BH1745_CLEAR_MSB),
        regmap_reg_range(BH1745_INTR, BH1745_INTR),
        regmap_reg_range(BH1745_PERSISTENCE, BH1745_TL_MSB),
        regmap_reg_range(BH1745_MANU_ID_REG, BH1745_MANU_ID_REG),
};

static const struct regmap_access_table bh1745_readable_regs = {
        .yes_ranges = bh1745_readable_ranges,
        .n_yes_ranges = ARRAY_SIZE(bh1745_readable_ranges),
};

static const struct regmap_range bh1745_writable_ranges[] = {
        regmap_reg_range(BH1745_SYS_CTRL, BH1745_MODE_CTRL2),
        regmap_reg_range(BH1745_INTR, BH1745_INTR),
        regmap_reg_range(BH1745_PERSISTENCE, BH1745_TL_MSB),
};

static const struct regmap_access_table bh1745_writable_regs = {
        .yes_ranges = bh1745_writable_ranges,
        .n_yes_ranges = ARRAY_SIZE(bh1745_writable_ranges),
};

static const struct regmap_config bh1745_regmap = {
        .reg_bits = 8,
        .val_bits = 8,
        .max_register = BH1745_MANU_ID_REG,
        .cache_type = REGCACHE_RBTREE,
        .volatile_table = &bh1745_volatile_regs,
        .wr_table = &bh1745_writable_regs,
        .rd_table = &bh1745_readable_regs,
};

static const struct iio_event_spec bh1745_event_spec[] = {
        {
                .type = IIO_EV_TYPE_THRESH,
                .dir = IIO_EV_DIR_RISING,
                .mask_shared_by_type = BIT(IIO_EV_INFO_VALUE),
        },
        {
                .type = IIO_EV_TYPE_THRESH,
                .dir = IIO_EV_DIR_FALLING,
                .mask_shared_by_type = BIT(IIO_EV_INFO_VALUE),
        },
        {
                .type = IIO_EV_TYPE_THRESH,
                .dir = IIO_EV_DIR_EITHER,
                .mask_shared_by_type = BIT(IIO_EV_INFO_PERIOD),
                .mask_separate = BIT(IIO_EV_INFO_ENABLE),
        },
};

#define BH1745_CHANNEL(_colour, _si, _addr)                             \
        {                                                               \
                .type = IIO_INTENSITY, .modified = 1,                   \
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
                .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE) |   \
                                           BIT(IIO_CHAN_INFO_INT_TIME), \
                .info_mask_shared_by_all_available =                    \
                        BIT(IIO_CHAN_INFO_SCALE) |                      \
                        BIT(IIO_CHAN_INFO_INT_TIME),                    \
                .event_spec = bh1745_event_spec,                        \
                .num_event_specs = ARRAY_SIZE(bh1745_event_spec),       \
                .channel2 = IIO_MOD_LIGHT_##_colour, .address = _addr,  \
                .scan_index = _si,                                      \
                .scan_type = {                                          \
                        .sign = 'u',                                    \
                        .realbits = 16,                                 \
                        .storagebits = 16,                              \
                        .endianness = IIO_CPU,                          \
                },                                                      \
        }

static const struct iio_chan_spec bh1745_channels[] = {
        BH1745_CHANNEL(RED, 0, BH1745_RED_LSB),
        BH1745_CHANNEL(GREEN, 1, BH1745_GREEN_LSB),
        BH1745_CHANNEL(BLUE, 2, BH1745_BLUE_LSB),
        BH1745_CHANNEL(CLEAR, 3, BH1745_CLEAR_LSB),
        IIO_CHAN_SOFT_TIMESTAMP(4),
};

static int bh1745_reset(struct bh1745_data *data)
{
        return regmap_set_bits(data->regmap, BH1745_SYS_CTRL,
                               BH1745_SYS_CTRL_SW_RESET |
                               BH1745_SYS_CTRL_INTR_RESET);
}

static int bh1745_power_on(struct bh1745_data *data)
{
        return regmap_set_bits(data->regmap, BH1745_MODE_CTRL2,
                               BH1745_CTRL2_RGBC_EN);
}

static void bh1745_power_off(void *data_ptr)
{
        struct bh1745_data *data = data_ptr;
        struct device *dev = data->dev;
        int ret;

        ret = regmap_clear_bits(data->regmap, BH1745_MODE_CTRL2,
                                BH1745_CTRL2_RGBC_EN);
        if (ret)
                dev_err(dev, "Failed to turn off device\n");
}

static int bh1745_get_scale(struct bh1745_data *data, int *val, int *val2)
{
        int ret;
        int value;
        int gain_sel, int_time_sel;
        int gain;
        const struct iio_itime_sel_mul *int_time;

        ret = regmap_read(data->regmap, BH1745_MODE_CTRL2, &value);
        if (ret)
                return ret;

        gain_sel = FIELD_GET(BH1745_CTRL2_ADC_GAIN_MASK, value);
        gain = iio_gts_find_gain_by_sel(&data->gts, gain_sel);

        ret = regmap_read(data->regmap, BH1745_MODE_CTRL1, &value);
        if (ret)
                return ret;

        int_time_sel = FIELD_GET(BH1745_CTRL1_MEASUREMENT_TIME_MASK, value);
        int_time = iio_gts_find_itime_by_sel(&data->gts, int_time_sel);

        return iio_gts_get_scale(&data->gts, gain, int_time->time_us, val,
                                 val2);
}

static int bh1745_set_scale(struct bh1745_data *data, int val)
{
        struct device *dev = data->dev;
        int ret;
        int value;
        int hw_gain_sel, current_int_time_sel, new_int_time_sel;

        ret = regmap_read(data->regmap, BH1745_MODE_CTRL1, &value);
        if (ret)
                return ret;

        current_int_time_sel = FIELD_GET(BH1745_CTRL1_MEASUREMENT_TIME_MASK,
                                         value);
        ret = iio_gts_find_gain_sel_for_scale_using_time(&data->gts,
                                                         current_int_time_sel,
                                                         val, 0, &hw_gain_sel);
        if (ret) {
                for (int i = 0; i < data->gts.num_itime; i++) {
                        new_int_time_sel = data->gts.itime_table[i].sel;

                        if (new_int_time_sel == current_int_time_sel)
                                continue;

                        ret = iio_gts_find_gain_sel_for_scale_using_time(&data->gts,
                                                                         new_int_time_sel,
                                                                         val, 0,
                                                                         &hw_gain_sel);
                        if (!ret)
                                break;
                }

                if (ret) {
                        dev_dbg(dev, "Unsupported scale value requested: %d\n",
                                val);
                        return -EINVAL;
                }

                ret = regmap_write_bits(data->regmap, BH1745_MODE_CTRL1,
                                        BH1745_CTRL1_MEASUREMENT_TIME_MASK,
                                        new_int_time_sel);
                if (ret)
                        return ret;
        }

        return regmap_write_bits(data->regmap, BH1745_MODE_CTRL2,
                                 BH1745_CTRL2_ADC_GAIN_MASK, hw_gain_sel);
}

static int bh1745_get_int_time(struct bh1745_data *data, int *val)
{
        int ret;
        int value;
        int int_time, int_time_sel;

        ret = regmap_read(data->regmap, BH1745_MODE_CTRL1, &value);
        if (ret)
                return ret;

        int_time_sel = FIELD_GET(BH1745_CTRL1_MEASUREMENT_TIME_MASK, value);
        int_time = iio_gts_find_int_time_by_sel(&data->gts, int_time_sel);
        if (int_time < 0)
                return int_time;

        *val = int_time;

        return 0;
}

static int bh1745_set_int_time(struct bh1745_data *data, int val, int val2)
{
        struct device *dev = data->dev;
        int ret;
        int value;
        int current_int_time, current_hwgain_sel, current_hwgain;
        int new_hwgain, new_hwgain_sel, new_int_time_sel;
        int req_int_time = (1000000 * val) + val2;

        if (!iio_gts_valid_time(&data->gts, req_int_time)) {
                dev_dbg(dev, "Unsupported integration time requested: %d\n",
                        req_int_time);
                return -EINVAL;
        }

        ret = bh1745_get_int_time(data, &current_int_time);
        if (ret)
                return ret;

        if (current_int_time == req_int_time)
                return 0;

        ret = regmap_read(data->regmap, BH1745_MODE_CTRL2, &value);
        if (ret)
                return ret;

        current_hwgain_sel = FIELD_GET(BH1745_CTRL2_ADC_GAIN_MASK, value);
        current_hwgain = iio_gts_find_gain_by_sel(&data->gts,
                                                  current_hwgain_sel);
        ret = iio_gts_find_new_gain_by_old_gain_time(&data->gts, current_hwgain,
                                                     current_int_time,
                                                     req_int_time,
                                                     &new_hwgain);
        if (new_hwgain < 0) {
                dev_dbg(dev, "No corresponding gain for requested integration time\n");
                return ret;
        }

        if (ret) {
                bool in_range;

                new_hwgain = iio_find_closest_gain_low(&data->gts, new_hwgain,
                                                       &in_range);
                if (new_hwgain < 0) {
                        new_hwgain = iio_gts_get_min_gain(&data->gts);
                        if (new_hwgain < 0)
                                return ret;
                }

                if (!in_range)
                        dev_dbg(dev, "Optimal gain out of range\n");

                dev_dbg(dev, "Scale changed, new hw_gain %d\n", new_hwgain);
        }

        new_hwgain_sel = iio_gts_find_sel_by_gain(&data->gts, new_hwgain);
        if (new_hwgain_sel < 0)
                return new_hwgain_sel;

        ret = regmap_write_bits(data->regmap, BH1745_MODE_CTRL2,
                                BH1745_CTRL2_ADC_GAIN_MASK,
                                new_hwgain_sel);
        if (ret)
                return ret;

        new_int_time_sel = iio_gts_find_sel_by_int_time(&data->gts,
                                                        req_int_time);
        if (new_int_time_sel < 0)
                return new_int_time_sel;

        return regmap_write_bits(data->regmap, BH1745_MODE_CTRL1,
                                 BH1745_CTRL1_MEASUREMENT_TIME_MASK,
                                 new_int_time_sel);
}

static int bh1745_read_raw(struct iio_dev *indio_dev,
                           struct iio_chan_spec const *chan,
                           int *val, int *val2, long mask)
{
        struct bh1745_data *data = iio_priv(indio_dev);
        int ret;
        int value;

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                if (!iio_device_claim_direct(indio_dev))
                        return -EBUSY;

                ret = regmap_bulk_read(data->regmap, chan->address, &value, 2);
                iio_device_release_direct(indio_dev);
                if (ret)
                        return ret;
                *val = value;

                return IIO_VAL_INT;

        case IIO_CHAN_INFO_SCALE: {
                        guard(mutex)(&data->lock);
                        ret = bh1745_get_scale(data, val, val2);
                        if (ret)
                                return ret;

                        return IIO_VAL_INT;
                }

        case IIO_CHAN_INFO_INT_TIME: {
                        guard(mutex)(&data->lock);
                        *val = 0;
                        ret = bh1745_get_int_time(data, val2);
                        if (ret)
                                return 0;

                        return IIO_VAL_INT_PLUS_MICRO;
                }

        default:
                return -EINVAL;
        }
}

static int bh1745_write_raw(struct iio_dev *indio_dev,
                            struct iio_chan_spec const *chan,
                            int val, int val2, long mask)
{
        struct bh1745_data *data = iio_priv(indio_dev);

        guard(mutex)(&data->lock);
        switch (mask) {
        case IIO_CHAN_INFO_SCALE:
                return bh1745_set_scale(data, val);

        case IIO_CHAN_INFO_INT_TIME:
                return bh1745_set_int_time(data, val, val2);

        default:
                return -EINVAL;
        }
}

static int bh1745_write_raw_get_fmt(struct iio_dev *indio_dev,
                                    struct iio_chan_spec const *chan,
                                    long mask)
{
        switch (mask) {
        case IIO_CHAN_INFO_SCALE:
                return IIO_VAL_INT;

        case IIO_CHAN_INFO_INT_TIME:
                return IIO_VAL_INT_PLUS_MICRO;

        default:
                return -EINVAL;
        }
}

static int bh1745_read_thresh(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 bh1745_data *data = iio_priv(indio_dev);
        int ret;

        switch (info) {
        case IIO_EV_INFO_VALUE:
                switch (dir) {
                case IIO_EV_DIR_RISING:
                        ret = regmap_bulk_read(data->regmap, BH1745_TH_LSB,
                                               val, 2);
                        if (ret)
                                return ret;

                        return IIO_VAL_INT;

                case IIO_EV_DIR_FALLING:
                        ret = regmap_bulk_read(data->regmap, BH1745_TL_LSB,
                                               val, 2);
                        if (ret)
                                return ret;

                        return IIO_VAL_INT;

                default:
                        return -EINVAL;
                }

        case IIO_EV_INFO_PERIOD:
                ret = regmap_read(data->regmap, BH1745_PERSISTENCE, val);
                if (ret)
                        return ret;

                return IIO_VAL_INT;

        default:
                return -EINVAL;
        }
}

static int bh1745_write_thresh(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 bh1745_data *data = iio_priv(indio_dev);
        int ret;

        switch (info) {
        case IIO_EV_INFO_VALUE:
                if (val < 0x0 || val > 0xFFFF)
                        return -EINVAL;

                switch (dir) {
                case IIO_EV_DIR_RISING:
                        ret = regmap_bulk_write(data->regmap, BH1745_TH_LSB,
                                                &val, 2);
                        if (ret)
                                return ret;

                        return IIO_VAL_INT;

                case IIO_EV_DIR_FALLING:
                        ret = regmap_bulk_write(data->regmap, BH1745_TL_LSB,
                                                &val, 2);
                        if (ret)
                                return ret;

                        return IIO_VAL_INT;

                default:
                        return -EINVAL;
                }

        case IIO_EV_INFO_PERIOD:
                if (val < BH1745_PRESISTENCE_UPDATE_TOGGLE ||
                    val > BH1745_PRESISTENCE_UPDATE_EIGHT_MEASUREMENT)
                        return -EINVAL;
                ret = regmap_write(data->regmap, BH1745_PERSISTENCE, val);
                if (ret)
                        return ret;

                return IIO_VAL_INT;

        default:
                return -EINVAL;
        }
}

static int bh1745_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 bh1745_data *data = iio_priv(indio_dev);
        int ret;
        int value;
        int int_src;

        ret = regmap_read(data->regmap, BH1745_INTR, &value);
        if (ret)
                return ret;

        if (!FIELD_GET(BH1745_INTR_ENABLE, value))
                return 0;

        int_src = FIELD_GET(BH1745_INTR_SOURCE_MASK, value);

        switch (chan->channel2) {
        case IIO_MOD_LIGHT_RED:
                if (int_src == BH1745_INTR_SOURCE_RED)
                        return 1;
                return 0;

        case IIO_MOD_LIGHT_GREEN:
                if (int_src == BH1745_INTR_SOURCE_GREEN)
                        return 1;
                return 0;

        case IIO_MOD_LIGHT_BLUE:
                if (int_src == BH1745_INTR_SOURCE_BLUE)
                        return 1;
                return 0;

        case IIO_MOD_LIGHT_CLEAR:
                if (int_src == BH1745_INTR_SOURCE_CLEAR)
                        return 1;
                return 0;

        default:
                return -EINVAL;
        }
}

static int bh1745_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 bh1745_data *data = iio_priv(indio_dev);
        int value;

        if (!state)
                return regmap_clear_bits(data->regmap,
                                         BH1745_INTR, BH1745_INTR_ENABLE);

        /* Latch is always enabled when enabling interrupt */
        value = BH1745_INTR_ENABLE;

        switch (chan->channel2) {
        case IIO_MOD_LIGHT_RED:
                return regmap_write(data->regmap, BH1745_INTR,
                                    value | FIELD_PREP(BH1745_INTR_SOURCE_MASK,
                                                       BH1745_INTR_SOURCE_RED));

        case IIO_MOD_LIGHT_GREEN:
                return regmap_write(data->regmap, BH1745_INTR,
                                    value | FIELD_PREP(BH1745_INTR_SOURCE_MASK,
                                                       BH1745_INTR_SOURCE_GREEN));

        case IIO_MOD_LIGHT_BLUE:
                return regmap_write(data->regmap, BH1745_INTR,
                                    value | FIELD_PREP(BH1745_INTR_SOURCE_MASK,
                                                       BH1745_INTR_SOURCE_BLUE));

        case IIO_MOD_LIGHT_CLEAR:
                return regmap_write(data->regmap, BH1745_INTR,
                                    value | FIELD_PREP(BH1745_INTR_SOURCE_MASK,
                                                       BH1745_INTR_SOURCE_CLEAR));

        default:
                return -EINVAL;
        }
}

static int bh1745_read_avail(struct iio_dev *indio_dev,
                             struct iio_chan_spec const *chan, const int **vals,
                             int *type, int *length, long mask)
{
        struct bh1745_data *data = iio_priv(indio_dev);

        switch (mask) {
        case IIO_CHAN_INFO_INT_TIME:
                return iio_gts_avail_times(&data->gts, vals, type, length);

        case IIO_CHAN_INFO_SCALE:
                return iio_gts_all_avail_scales(&data->gts, vals, type, length);

        default:
                return -EINVAL;
        }
}

static const struct iio_info bh1745_info = {
        .read_raw = bh1745_read_raw,
        .write_raw = bh1745_write_raw,
        .write_raw_get_fmt = bh1745_write_raw_get_fmt,
        .read_event_value = bh1745_read_thresh,
        .write_event_value = bh1745_write_thresh,
        .read_event_config = bh1745_read_event_config,
        .write_event_config = bh1745_write_event_config,
        .read_avail = bh1745_read_avail,
};

static irqreturn_t bh1745_interrupt_handler(int interrupt, void *p)
{
        struct iio_dev *indio_dev = p;
        struct bh1745_data *data = iio_priv(indio_dev);
        int ret;
        int value;
        int int_src;

        ret = regmap_read(data->regmap, BH1745_INTR, &value);
        if (ret)
                return IRQ_NONE;

        int_src = FIELD_GET(BH1745_INTR_SOURCE_MASK, value);

        if (value & BH1745_INTR_STATUS) {
                iio_push_event(indio_dev,
                               IIO_UNMOD_EVENT_CODE(IIO_INTENSITY, int_src,
                                                    IIO_EV_TYPE_THRESH,
                                                    IIO_EV_DIR_EITHER),
                               iio_get_time_ns(indio_dev));

                return IRQ_HANDLED;
        }

        return IRQ_NONE;
}

static irqreturn_t bh1745_trigger_handler(int interrupt, void *p)
{
        struct iio_poll_func *pf = p;
        struct iio_dev *indio_dev = pf->indio_dev;
        struct bh1745_data *data = iio_priv(indio_dev);
        struct {
                u16 chans[4];
                aligned_s64 timestamp;
        } scan = { };
        u16 value;
        int ret;
        int i;
        int j = 0;

        iio_for_each_active_channel(indio_dev, i) {
                ret = regmap_bulk_read(data->regmap, BH1745_RED_LSB + 2 * i,
                                       &value, 2);
                if (ret)
                        goto err;

                scan.chans[j++] = value;
        }

        iio_push_to_buffers_with_ts(indio_dev, &scan, sizeof(scan),
                                    iio_get_time_ns(indio_dev));

err:
        iio_trigger_notify_done(indio_dev->trig);

        return IRQ_HANDLED;
}

static int bh1745_setup_triggered_buffer(struct iio_dev *indio_dev,
                                         struct device *parent,
                                         int irq)
{
        struct bh1745_data *data = iio_priv(indio_dev);
        struct device *dev = data->dev;
        int ret;

        ret = devm_iio_triggered_buffer_setup(parent, indio_dev, NULL,
                                              bh1745_trigger_handler, NULL);
        if (ret)
                return dev_err_probe(dev, ret,
                                     "Triggered buffer setup failed\n");

        if (irq) {
                ret = devm_request_threaded_irq(dev, irq, NULL,
                                                bh1745_interrupt_handler,
                                                IRQF_ONESHOT,
                                                "bh1745_interrupt", indio_dev);
                if (ret)
                        return dev_err_probe(dev, ret,
                                             "Request for IRQ failed\n");
        }

        return 0;
}

static int bh1745_init(struct bh1745_data *data)
{
        int ret;
        struct device *dev = data->dev;

        mutex_init(&data->lock);

        ret = devm_iio_init_iio_gts(dev, BH1745_MAX_GAIN, 0, bh1745_gain,
                                    ARRAY_SIZE(bh1745_gain), bh1745_itimes,
                                    ARRAY_SIZE(bh1745_itimes), &data->gts);
        if (ret)
                return ret;

        ret = bh1745_reset(data);
        if (ret)
                return dev_err_probe(dev, ret, "Failed to reset sensor\n");

        ret = bh1745_power_on(data);
        if (ret)
                return dev_err_probe(dev, ret, "Failed to turn on sensor\n");

        ret = devm_add_action_or_reset(dev, bh1745_power_off, data);
        if (ret)
                return ret;

        return 0;
}

static int bh1745_probe(struct i2c_client *client)
{
        int ret;
        int value;
        int part_id;
        struct bh1745_data *data;
        struct iio_dev *indio_dev;
        struct device *dev = &client->dev;

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

        indio_dev->info = &bh1745_info;
        indio_dev->name = "bh1745";
        indio_dev->channels = bh1745_channels;
        indio_dev->modes = INDIO_DIRECT_MODE;
        indio_dev->num_channels = ARRAY_SIZE(bh1745_channels);
        data = iio_priv(indio_dev);
        data->dev = &client->dev;
        data->regmap = devm_regmap_init_i2c(client, &bh1745_regmap);
        if (IS_ERR(data->regmap))
                return dev_err_probe(dev, PTR_ERR(data->regmap),
                                     "Failed to initialize Regmap\n");

        ret = regmap_read(data->regmap, BH1745_SYS_CTRL, &value);
        if (ret)
                return ret;

        part_id = FIELD_GET(BH1745_SYS_CTRL_PART_ID_MASK, value);
        if (part_id != BH1745_PART_ID)
                dev_warn(dev, "Unknown part ID 0x%x\n", part_id);

        ret = devm_regulator_get_enable(dev, "vdd");
        if (ret)
                return dev_err_probe(dev, ret,
                                     "Failed to get and enable regulator\n");

        ret = bh1745_init(data);
        if (ret)
                return ret;

        ret = bh1745_setup_triggered_buffer(indio_dev, indio_dev->dev.parent,
                                            client->irq);
        if (ret)
                return ret;

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

        return 0;
}

static const struct i2c_device_id bh1745_idtable[] = {
        { "bh1745" },
        { }
};
MODULE_DEVICE_TABLE(i2c, bh1745_idtable);

static const struct of_device_id bh1745_of_match[] = {
        { .compatible = "rohm,bh1745" },
        { }
};
MODULE_DEVICE_TABLE(of, bh1745_of_match);

static struct i2c_driver bh1745_driver = {
        .driver = {
                .name = "bh1745",
                .of_match_table = bh1745_of_match,
        },
        .probe = bh1745_probe,
        .id_table = bh1745_idtable,
};
module_i2c_driver(bh1745_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Mudit Sharma <muditsharma.info@gmail.com>");
MODULE_DESCRIPTION("BH1745 colour sensor driver");
MODULE_IMPORT_NS("IIO_GTS_HELPER");