// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2025 Invensense, Inc.
 */

#include <linux/delay.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/math64.h>
#include <linux/mutex.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/types.h>

#include <linux/iio/buffer.h>
#include <linux/iio/common/inv_sensors_timestamp.h>
#include <linux/iio/iio.h>
#include <linux/iio/kfifo_buf.h>

#include "inv_icm45600_buffer.h"
#include "inv_icm45600.h"

enum inv_icm45600_gyro_scan {
        INV_ICM45600_GYRO_SCAN_X,
        INV_ICM45600_GYRO_SCAN_Y,
        INV_ICM45600_GYRO_SCAN_Z,
        INV_ICM45600_GYRO_SCAN_TEMP,
        INV_ICM45600_GYRO_SCAN_TIMESTAMP,
};

static const struct iio_chan_spec_ext_info inv_icm45600_gyro_ext_infos[] = {
        IIO_MOUNT_MATRIX(IIO_SHARED_BY_ALL, inv_icm45600_get_mount_matrix),
        { }
};

#define INV_ICM45600_GYRO_CHAN(_modifier, _index, _ext_info)            \
        {                                                               \
                .type = IIO_ANGL_VEL,                                   \
                .modified = 1,                                          \
                .channel2 = _modifier,                                  \
                .info_mask_separate =                                   \
                        BIT(IIO_CHAN_INFO_RAW) |                        \
                        BIT(IIO_CHAN_INFO_CALIBBIAS),                   \
                .info_mask_shared_by_type =                             \
                        BIT(IIO_CHAN_INFO_SCALE),                       \
                .info_mask_shared_by_type_available =                   \
                        BIT(IIO_CHAN_INFO_SCALE) |                      \
                        BIT(IIO_CHAN_INFO_CALIBBIAS),                   \
                .info_mask_shared_by_all =                              \
                        BIT(IIO_CHAN_INFO_SAMP_FREQ),                   \
                .info_mask_shared_by_all_available =                    \
                        BIT(IIO_CHAN_INFO_SAMP_FREQ),                   \
                .scan_index = _index,                                   \
                .scan_type = {                                          \
                        .sign = 's',                                    \
                        .realbits = 16,                                 \
                        .storagebits = 16,                              \
                        .endianness = IIO_LE,                           \
                },                                                      \
                .ext_info = _ext_info,                                  \
        }

static const struct iio_chan_spec inv_icm45600_gyro_channels[] = {
        INV_ICM45600_GYRO_CHAN(IIO_MOD_X, INV_ICM45600_GYRO_SCAN_X,
                               inv_icm45600_gyro_ext_infos),
        INV_ICM45600_GYRO_CHAN(IIO_MOD_Y, INV_ICM45600_GYRO_SCAN_Y,
                               inv_icm45600_gyro_ext_infos),
        INV_ICM45600_GYRO_CHAN(IIO_MOD_Z, INV_ICM45600_GYRO_SCAN_Z,
                               inv_icm45600_gyro_ext_infos),
        INV_ICM45600_TEMP_CHAN(INV_ICM45600_GYRO_SCAN_TEMP),
        IIO_CHAN_SOFT_TIMESTAMP(INV_ICM45600_GYRO_SCAN_TIMESTAMP),
};

/*
 * IIO buffer data: size must be a power of 2 and timestamp aligned
 * 16 bytes: 6 bytes angular velocity, 2 bytes temperature, 8 bytes timestamp
 */
struct inv_icm45600_gyro_buffer {
        struct inv_icm45600_fifo_sensor_data gyro;
        s16 temp;
        aligned_s64 timestamp;
};

static const unsigned long inv_icm45600_gyro_scan_masks[] = {
        /* 3-axis gyro + temperature */
        BIT(INV_ICM45600_GYRO_SCAN_X) |
        BIT(INV_ICM45600_GYRO_SCAN_Y) |
        BIT(INV_ICM45600_GYRO_SCAN_Z) |
        BIT(INV_ICM45600_GYRO_SCAN_TEMP),
        0
};

/* enable gyroscope sensor and FIFO write */
static int inv_icm45600_gyro_update_scan_mode(struct iio_dev *indio_dev,
                                              const unsigned long *scan_mask)
{
        struct inv_icm45600_state *st = iio_device_get_drvdata(indio_dev);
        struct inv_icm45600_sensor_state *gyro_st = iio_priv(indio_dev);
        struct inv_icm45600_sensor_conf conf = INV_ICM45600_SENSOR_CONF_KEEP_VALUES;
        unsigned int fifo_en = 0;
        unsigned int sleep = 0;
        int ret;

        scoped_guard(mutex, &st->lock) {
                if (*scan_mask & BIT(INV_ICM45600_GYRO_SCAN_TEMP))
                        fifo_en |= INV_ICM45600_SENSOR_TEMP;

                if (*scan_mask & (BIT(INV_ICM45600_GYRO_SCAN_X) |
                                 BIT(INV_ICM45600_GYRO_SCAN_Y) |
                                 BIT(INV_ICM45600_GYRO_SCAN_Z))) {
                        /* enable gyro sensor */
                        conf.mode = gyro_st->power_mode;
                        ret = inv_icm45600_set_gyro_conf(st, &conf, &sleep);
                        if (ret)
                                return ret;
                        fifo_en |= INV_ICM45600_SENSOR_GYRO;
                }
                ret = inv_icm45600_buffer_set_fifo_en(st, fifo_en | st->fifo.en);
        }
        if (sleep)
                msleep(sleep);

        return ret;
}

static int _inv_icm45600_gyro_read_sensor(struct inv_icm45600_state *st,
                                          struct inv_icm45600_sensor_state *gyro_st,
                                          unsigned int reg, int *val)
{
        struct inv_icm45600_sensor_conf conf = INV_ICM45600_SENSOR_CONF_KEEP_VALUES;
        int ret;

        /* enable gyro sensor */
        conf.mode = gyro_st->power_mode;
        ret = inv_icm45600_set_gyro_conf(st, &conf, NULL);
        if (ret)
                return ret;

        /* read gyro register data */
        ret = regmap_bulk_read(st->map, reg, &st->buffer.u16, sizeof(st->buffer.u16));
        if (ret)
                return ret;

        *val = sign_extend32(le16_to_cpup(&st->buffer.u16), 15);
        if (*val == INV_ICM45600_DATA_INVALID)
                return -ENODATA;

        return 0;
}

static int inv_icm45600_gyro_read_sensor(struct iio_dev *indio_dev,
                                         struct iio_chan_spec const *chan,
                                         int *val)
{
        struct inv_icm45600_state *st = iio_device_get_drvdata(indio_dev);
        struct inv_icm45600_sensor_state *gyro_st = iio_priv(indio_dev);
        struct device *dev = regmap_get_device(st->map);
        unsigned int reg;
        int ret;

        if (chan->type != IIO_ANGL_VEL)
                return -EINVAL;

        switch (chan->channel2) {
        case IIO_MOD_X:
                reg = INV_ICM45600_REG_GYRO_DATA_X;
                break;
        case IIO_MOD_Y:
                reg = INV_ICM45600_REG_GYRO_DATA_Y;
                break;
        case IIO_MOD_Z:
                reg = INV_ICM45600_REG_GYRO_DATA_Z;
                break;
        default:
                return -EINVAL;
        }

        ret = pm_runtime_resume_and_get(dev);
        if (ret)
                return ret;

        scoped_guard(mutex, &st->lock)
                ret = _inv_icm45600_gyro_read_sensor(st, gyro_st, reg, val);

        pm_runtime_put_autosuspend(dev);

        return ret;
}

/* IIO format int + nano */
const int inv_icm45600_gyro_scale[][2] = {
        /* +/- 2000dps => 0.001065264 rad/s */
        [INV_ICM45600_GYRO_FS_2000DPS] = { 0, 1065264 },
        /* +/- 1000dps => 0.000532632 rad/s */
        [INV_ICM45600_GYRO_FS_1000DPS] = { 0, 532632 },
        /* +/- 500dps => 0.000266316 rad/s */
        [INV_ICM45600_GYRO_FS_500DPS] = { 0, 266316 },
        /* +/- 250dps => 0.000133158 rad/s */
        [INV_ICM45600_GYRO_FS_250DPS] = { 0, 133158 },
        /* +/- 125dps => 0.000066579 rad/s */
        [INV_ICM45600_GYRO_FS_125DPS] = { 0, 66579 },
        /* +/- 62.5dps => 0.000033290 rad/s */
        [INV_ICM45600_GYRO_FS_62_5DPS] = { 0, 33290 },
        /* +/- 31.25dps => 0.000016645 rad/s */
        [INV_ICM45600_GYRO_FS_31_25DPS] = { 0, 16645 },
        /* +/- 15.625dps => 0.000008322 rad/s */
        [INV_ICM45600_GYRO_FS_15_625DPS] = { 0, 8322 },
};

/* IIO format int + nano */
const int inv_icm45686_gyro_scale[][2] = {
        /* +/- 4000dps => 0.002130529 rad/s */
        [INV_ICM45686_GYRO_FS_4000DPS] = { 0, 2130529 },
        /* +/- 2000dps => 0.001065264 rad/s */
        [INV_ICM45686_GYRO_FS_2000DPS] = { 0, 1065264 },
        /* +/- 1000dps => 0.000532632 rad/s */
        [INV_ICM45686_GYRO_FS_1000DPS] = { 0, 532632 },
        /* +/- 500dps => 0.000266316 rad/s */
        [INV_ICM45686_GYRO_FS_500DPS] = { 0, 266316 },
        /* +/- 250dps => 0.000133158 rad/s */
        [INV_ICM45686_GYRO_FS_250DPS] = { 0, 133158 },
        /* +/- 125dps => 0.000066579 rad/s */
        [INV_ICM45686_GYRO_FS_125DPS] = { 0, 66579 },
        /* +/- 62.5dps => 0.000033290 rad/s */
        [INV_ICM45686_GYRO_FS_62_5DPS] = { 0, 33290 },
        /* +/- 31.25dps => 0.000016645 rad/s */
        [INV_ICM45686_GYRO_FS_31_25DPS] = { 0, 16645 },
        /* +/- 15.625dps => 0.000008322 rad/s */
        [INV_ICM45686_GYRO_FS_15_625DPS] = { 0, 8322 },
};

static int inv_icm45600_gyro_read_scale(struct iio_dev *indio_dev,
                                        int *val, int *val2)
{
        struct inv_icm45600_state *st = iio_device_get_drvdata(indio_dev);
        struct inv_icm45600_sensor_state *gyro_st = iio_priv(indio_dev);
        unsigned int idx;

        idx = st->conf.gyro.fs;

        /* Full scale register starts at 1 for not High FSR parts */
        if (gyro_st->scales ==  (const int *)&inv_icm45600_gyro_scale)
                idx--;

        *val = gyro_st->scales[2 * idx];
        *val2 = gyro_st->scales[2 * idx + 1];
        return IIO_VAL_INT_PLUS_NANO;
}

static int inv_icm45600_gyro_write_scale(struct iio_dev *indio_dev,
                                         int val, int val2)
{
        struct inv_icm45600_state *st = iio_device_get_drvdata(indio_dev);
        struct inv_icm45600_sensor_state *gyro_st = iio_priv(indio_dev);
        struct device *dev = regmap_get_device(st->map);
        unsigned int idx;
        struct inv_icm45600_sensor_conf conf = INV_ICM45600_SENSOR_CONF_KEEP_VALUES;
        int ret;

        for (idx = 0; idx < gyro_st->scales_len; idx += 2) {
                if (val == gyro_st->scales[idx] &&
                    val2 == gyro_st->scales[idx + 1])
                        break;
        }
        if (idx == gyro_st->scales_len)
                return -EINVAL;

        conf.fs = idx / 2;

        /* Full scale register starts at 1 for not High FSR parts */
        if (gyro_st->scales == (const int *)&inv_icm45600_gyro_scale)
                conf.fs++;

        ret = pm_runtime_resume_and_get(dev);
        if (ret)
                return ret;

        scoped_guard(mutex, &st->lock)
                ret = inv_icm45600_set_gyro_conf(st, &conf, NULL);

        pm_runtime_put_autosuspend(dev);

        return ret;
}

/* IIO format int + micro */
static const int inv_icm45600_gyro_odr[] = {
        1, 562500,      /* 1.5625Hz */
        3, 125000,      /* 3.125Hz */
        6, 250000,      /* 6.25Hz */
        12, 500000,     /* 12.5Hz */
        25, 0,          /* 25Hz */
        50, 0,          /* 50Hz */
        100, 0,         /* 100Hz */
        200, 0,         /* 200Hz */
        400, 0,         /* 400Hz */
        800, 0,         /* 800Hz */
        1600, 0,        /* 1.6kHz */
        3200, 0,        /* 3.2kHz */
        6400, 0,        /* 6.4kHz */
};

static const int inv_icm45600_gyro_odr_conv[] = {
        INV_ICM45600_ODR_1_5625HZ_LP,
        INV_ICM45600_ODR_3_125HZ_LP,
        INV_ICM45600_ODR_6_25HZ_LP,
        INV_ICM45600_ODR_12_5HZ,
        INV_ICM45600_ODR_25HZ,
        INV_ICM45600_ODR_50HZ,
        INV_ICM45600_ODR_100HZ,
        INV_ICM45600_ODR_200HZ,
        INV_ICM45600_ODR_400HZ,
        INV_ICM45600_ODR_800HZ_LN,
        INV_ICM45600_ODR_1600HZ_LN,
        INV_ICM45600_ODR_3200HZ_LN,
        INV_ICM45600_ODR_6400HZ_LN,
};

static int inv_icm45600_gyro_read_odr(struct inv_icm45600_state *st,
                                      int *val, int *val2)
{
        unsigned int odr;
        unsigned int i;

        odr = st->conf.gyro.odr;

        for (i = 0; i < ARRAY_SIZE(inv_icm45600_gyro_odr_conv); ++i) {
                if (inv_icm45600_gyro_odr_conv[i] == odr)
                        break;
        }
        if (i >= ARRAY_SIZE(inv_icm45600_gyro_odr_conv))
                return -EINVAL;

        *val = inv_icm45600_gyro_odr[2 * i];
        *val2 = inv_icm45600_gyro_odr[2 * i + 1];

        return IIO_VAL_INT_PLUS_MICRO;
}

static int _inv_icm45600_gyro_write_odr(struct iio_dev *indio_dev, int odr)
{
        struct inv_icm45600_state *st = iio_device_get_drvdata(indio_dev);
        struct inv_icm45600_sensor_state *gyro_st = iio_priv(indio_dev);
        struct inv_sensors_timestamp *ts = &gyro_st->ts;
        struct inv_icm45600_sensor_conf conf = INV_ICM45600_SENSOR_CONF_KEEP_VALUES;
        int ret;

        conf.odr = odr;
        ret = inv_sensors_timestamp_update_odr(ts, inv_icm45600_odr_to_period(conf.odr),
                                                iio_buffer_enabled(indio_dev));
        if (ret)
                return ret;

        if (st->conf.gyro.mode != INV_ICM45600_SENSOR_MODE_OFF)
                conf.mode = gyro_st->power_mode;

        ret = inv_icm45600_set_gyro_conf(st, &conf, NULL);
        if (ret)
                return ret;

        inv_icm45600_buffer_update_fifo_period(st);
        inv_icm45600_buffer_update_watermark(st);

        return 0;
}

static int inv_icm45600_gyro_write_odr(struct iio_dev *indio_dev,
                                       int val, int val2)
{
        struct inv_icm45600_state *st = iio_device_get_drvdata(indio_dev);
        struct device *dev = regmap_get_device(st->map);
        unsigned int idx;
        int odr;
        int ret;

        for (idx = 0; idx < ARRAY_SIZE(inv_icm45600_gyro_odr); idx += 2) {
                if (val == inv_icm45600_gyro_odr[idx] &&
                    val2 == inv_icm45600_gyro_odr[idx + 1])
                        break;
        }
        if (idx >= ARRAY_SIZE(inv_icm45600_gyro_odr))
                return -EINVAL;

        odr = inv_icm45600_gyro_odr_conv[idx / 2];

        ret = pm_runtime_resume_and_get(dev);
        if (ret)
                return ret;

        scoped_guard(mutex, &st->lock)
                ret = _inv_icm45600_gyro_write_odr(indio_dev, odr);

        pm_runtime_put_autosuspend(dev);

        return ret;
}

/*
 * Calibration bias values, IIO range format int + nano.
 * Value is limited to +/-62.5dps coded on 14 bits signed. Step is 7.5mdps.
 */
static int inv_icm45600_gyro_calibbias[] = {
        -1, 90830336,   /* min: -1.090830336 rad/s */
        0, 133158,      /* step: 0.000133158 rad/s */
        1, 90697178,    /* max: 1.090697178 rad/s */
};

static int inv_icm45600_gyro_read_offset(struct inv_icm45600_state *st,
                                         struct iio_chan_spec const *chan,
                                         int *val, int *val2)
{
        struct device *dev = regmap_get_device(st->map);
        s64 val64;
        s32 bias;
        unsigned int reg;
        s16 offset;
        int ret;

        if (chan->type != IIO_ANGL_VEL)
                return -EINVAL;

        switch (chan->channel2) {
        case IIO_MOD_X:
                reg = INV_ICM45600_IPREG_SYS1_REG_42;
                break;
        case IIO_MOD_Y:
                reg = INV_ICM45600_IPREG_SYS1_REG_56;
                break;
        case IIO_MOD_Z:
                reg = INV_ICM45600_IPREG_SYS1_REG_70;
                break;
        default:
                return -EINVAL;
        }

        ret = pm_runtime_resume_and_get(dev);
        if (ret)
                return ret;

        scoped_guard(mutex, &st->lock)
                ret = regmap_bulk_read(st->map, reg, &st->buffer.u16, sizeof(st->buffer.u16));

        pm_runtime_put_autosuspend(dev);
        if (ret)
                return ret;

        offset = le16_to_cpup(&st->buffer.u16) & INV_ICM45600_GYRO_OFFUSER_MASK;
        /* 14 bits signed value */
        offset = sign_extend32(offset, 13);

        /*
         * convert raw offset to dps then to rad/s
         * 14 bits signed raw max 62.5 to dps: 625 / 81920
         * dps to rad: Pi / 180
         * result in nano (1000000000)
         * (offset * 625 * Pi * 1000000000) / (81920 * 180)
         */
        val64 = (s64)offset * 625LL * 3141592653LL;
        /* for rounding, add + or - divisor (81920 * 180) divided by 2 */
        if (val64 >= 0)
                val64 += 81920 * 180 / 2;
        else
                val64 -= 81920 * 180 / 2;
        bias = div_s64(val64, 81920 * 180);
        *val = bias / 1000000000L;
        *val2 = bias % 1000000000L;

        return IIO_VAL_INT_PLUS_NANO;
}

static int inv_icm45600_gyro_write_offset(struct inv_icm45600_state *st,
                                          struct iio_chan_spec const *chan,
                                          int val, int val2)
{
        struct device *dev = regmap_get_device(st->map);
        s64 val64, min, max;
        unsigned int reg;
        s16 offset;
        int ret;

        if (chan->type != IIO_ANGL_VEL)
                return -EINVAL;

        switch (chan->channel2) {
        case IIO_MOD_X:
                reg = INV_ICM45600_IPREG_SYS1_REG_42;
                break;
        case IIO_MOD_Y:
                reg = INV_ICM45600_IPREG_SYS1_REG_56;
                break;
        case IIO_MOD_Z:
                reg = INV_ICM45600_IPREG_SYS1_REG_70;
                break;
        default:
                return -EINVAL;
        }

        /* inv_icm45600_gyro_calibbias: min - step - max in nano */
        min = (s64)inv_icm45600_gyro_calibbias[0] * 1000000000LL -
              (s64)inv_icm45600_gyro_calibbias[1];
        max = (s64)inv_icm45600_gyro_calibbias[4] * 1000000000LL +
              (s64)inv_icm45600_gyro_calibbias[5];
        val64 = (s64)val * 1000000000LL;
        if (val >= 0)
                val64 += (s64)val2;
        else
                val64 -= (s64)val2;
        if (val64 < min || val64 > max)
                return -EINVAL;

        /*
         * convert rad/s to dps then to raw value
         * rad to dps: 180 / Pi
         * dps to raw 14 bits signed, max 62.5: 8192 / 62.5
         * val in nano (1000000000)
         * val * 180 * 8192 / (Pi * 1000000000 * 62.5)
         */
        val64 = val64 * 180LL * 8192;
        /* for rounding, add + or - divisor (314159265 * 625) divided by 2 */
        if (val64 >= 0)
                val64 += 314159265LL * 625LL / 2LL;
        else
                val64 -= 314159265LL * 625LL / 2LL;
        offset = div64_s64(val64, 314159265LL * 625LL);

        /* clamp value limited to 14 bits signed */
        offset = clamp(offset, -8192, 8191);

        st->buffer.u16 = cpu_to_le16(offset & INV_ICM45600_GYRO_OFFUSER_MASK);

        ret = pm_runtime_resume_and_get(dev);
        if (ret)
                return ret;

        scoped_guard(mutex, &st->lock)
                ret = regmap_bulk_write(st->map, reg, &st->buffer.u16, sizeof(st->buffer.u16));

        pm_runtime_put_autosuspend(dev);
        return ret;
}

static int inv_icm45600_gyro_read_raw(struct iio_dev *indio_dev,
                                      struct iio_chan_spec const *chan,
                                      int *val, int *val2, long mask)
{
        struct inv_icm45600_state *st = iio_device_get_drvdata(indio_dev);
        int ret;

        switch (chan->type) {
        case IIO_ANGL_VEL:
                break;
        case IIO_TEMP:
                return inv_icm45600_temp_read_raw(indio_dev, chan, val, val2, mask);
        default:
                return -EINVAL;
        }

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                if (!iio_device_claim_direct(indio_dev))
                        return -EBUSY;
                ret = inv_icm45600_gyro_read_sensor(indio_dev, chan, val);
                iio_device_release_direct(indio_dev);
                if (ret)
                        return ret;
                return IIO_VAL_INT;
        case IIO_CHAN_INFO_SCALE:
                return inv_icm45600_gyro_read_scale(indio_dev, val, val2);
        case IIO_CHAN_INFO_SAMP_FREQ:
                return inv_icm45600_gyro_read_odr(st, val, val2);
        case IIO_CHAN_INFO_CALIBBIAS:
                return inv_icm45600_gyro_read_offset(st, chan, val, val2);
        default:
                return -EINVAL;
        }
}

static int inv_icm45600_gyro_read_avail(struct iio_dev *indio_dev,
                                        struct iio_chan_spec const *chan,
                                        const int **vals,
                                        int *type, int *length, long mask)
{
        struct inv_icm45600_sensor_state *gyro_st = iio_priv(indio_dev);

        if (chan->type != IIO_ANGL_VEL)
                return -EINVAL;

        switch (mask) {
        case IIO_CHAN_INFO_SCALE:
                *vals = gyro_st->scales;
                *type = IIO_VAL_INT_PLUS_NANO;
                *length = gyro_st->scales_len;
                return IIO_AVAIL_LIST;
        case IIO_CHAN_INFO_SAMP_FREQ:
                *vals = inv_icm45600_gyro_odr;
                *type = IIO_VAL_INT_PLUS_MICRO;
                *length = ARRAY_SIZE(inv_icm45600_gyro_odr);
                return IIO_AVAIL_LIST;
        case IIO_CHAN_INFO_CALIBBIAS:
                *vals = inv_icm45600_gyro_calibbias;
                *type = IIO_VAL_INT_PLUS_NANO;
                return IIO_AVAIL_RANGE;
        default:
                return -EINVAL;
        }
}

static int inv_icm45600_gyro_write_raw(struct iio_dev *indio_dev,
                                       struct iio_chan_spec const *chan,
                                       int val, int val2, long mask)
{
        struct inv_icm45600_state *st = iio_device_get_drvdata(indio_dev);
        int ret;

        if (chan->type != IIO_ANGL_VEL)
                return -EINVAL;

        switch (mask) {
        case IIO_CHAN_INFO_SCALE:
                if (!iio_device_claim_direct(indio_dev))
                        return -EBUSY;
                ret = inv_icm45600_gyro_write_scale(indio_dev, val, val2);
                iio_device_release_direct(indio_dev);
                return ret;
        case IIO_CHAN_INFO_SAMP_FREQ:
                return inv_icm45600_gyro_write_odr(indio_dev, val, val2);
        case IIO_CHAN_INFO_CALIBBIAS:
                if (!iio_device_claim_direct(indio_dev))
                        return -EBUSY;
                ret = inv_icm45600_gyro_write_offset(st, chan, val, val2);
                iio_device_release_direct(indio_dev);
                return ret;
        default:
                return -EINVAL;
        }
}

static int inv_icm45600_gyro_write_raw_get_fmt(struct iio_dev *indio_dev,
                                               struct iio_chan_spec const *chan,
                                               long mask)
{
        if (chan->type != IIO_ANGL_VEL)
                return -EINVAL;

        switch (mask) {
        case IIO_CHAN_INFO_SCALE:
                return IIO_VAL_INT_PLUS_NANO;
        case IIO_CHAN_INFO_SAMP_FREQ:
                return IIO_VAL_INT_PLUS_MICRO;
        case IIO_CHAN_INFO_CALIBBIAS:
                return IIO_VAL_INT_PLUS_NANO;
        default:
                return -EINVAL;
        }
}

static int inv_icm45600_gyro_hwfifo_set_watermark(struct iio_dev *indio_dev,
                                                  unsigned int val)
{
        struct inv_icm45600_state *st = iio_device_get_drvdata(indio_dev);

        guard(mutex)(&st->lock);

        st->fifo.watermark.gyro = val;
        return inv_icm45600_buffer_update_watermark(st);
}

static int inv_icm45600_gyro_hwfifo_flush(struct iio_dev *indio_dev,
                                          unsigned int count)
{
        struct inv_icm45600_state *st = iio_device_get_drvdata(indio_dev);
        int ret;

        if (count == 0)
                return 0;

        guard(mutex)(&st->lock);

        ret = inv_icm45600_buffer_hwfifo_flush(st, count);
        if (ret)
                return ret;

        return st->fifo.nb.gyro;
}

static const struct iio_info inv_icm45600_gyro_info = {
        .read_raw = inv_icm45600_gyro_read_raw,
        .read_avail = inv_icm45600_gyro_read_avail,
        .write_raw = inv_icm45600_gyro_write_raw,
        .write_raw_get_fmt = inv_icm45600_gyro_write_raw_get_fmt,
        .debugfs_reg_access = inv_icm45600_debugfs_reg,
        .update_scan_mode = inv_icm45600_gyro_update_scan_mode,
        .hwfifo_set_watermark = inv_icm45600_gyro_hwfifo_set_watermark,
        .hwfifo_flush_to_buffer = inv_icm45600_gyro_hwfifo_flush,
};

struct iio_dev *inv_icm45600_gyro_init(struct inv_icm45600_state *st)
{
        struct device *dev = regmap_get_device(st->map);
        struct inv_icm45600_sensor_state *gyro_st;
        struct inv_sensors_timestamp_chip ts_chip;
        struct iio_dev *indio_dev;
        const char *name;
        int ret;

        name = devm_kasprintf(dev, GFP_KERNEL, "%s-gyro", st->chip_info->name);
        if (!name)
                return ERR_PTR(-ENOMEM);

        indio_dev = devm_iio_device_alloc(dev, sizeof(*gyro_st));
        if (!indio_dev)
                return ERR_PTR(-ENOMEM);
        gyro_st = iio_priv(indio_dev);

        gyro_st->scales = st->chip_info->gyro_scales;
        gyro_st->scales_len = st->chip_info->gyro_scales_len * 2;

        /* low-noise by default at init */
        gyro_st->power_mode = INV_ICM45600_SENSOR_MODE_LOW_NOISE;

        /*
         * clock period is 32kHz (31250ns)
         * jitter is +/- 2% (20 per mille)
         */
        ts_chip.clock_period = 31250;
        ts_chip.jitter = 20;
        ts_chip.init_period = inv_icm45600_odr_to_period(st->conf.gyro.odr);
        inv_sensors_timestamp_init(&gyro_st->ts, &ts_chip);

        iio_device_set_drvdata(indio_dev, st);
        indio_dev->name = name;
        indio_dev->info = &inv_icm45600_gyro_info;
        indio_dev->modes = INDIO_DIRECT_MODE;
        indio_dev->channels = inv_icm45600_gyro_channels;
        indio_dev->num_channels = ARRAY_SIZE(inv_icm45600_gyro_channels);
        indio_dev->available_scan_masks = inv_icm45600_gyro_scan_masks;
        indio_dev->setup_ops = &inv_icm45600_buffer_ops;

        ret = devm_iio_kfifo_buffer_setup(dev, indio_dev,
                                          &inv_icm45600_buffer_ops);
        if (ret)
                return ERR_PTR(ret);

        ret = devm_iio_device_register(dev, indio_dev);
        if (ret)
                return ERR_PTR(ret);

        return indio_dev;
}

int inv_icm45600_gyro_parse_fifo(struct iio_dev *indio_dev)
{
        struct inv_icm45600_state *st = iio_device_get_drvdata(indio_dev);
        struct inv_icm45600_sensor_state *gyro_st = iio_priv(indio_dev);
        struct inv_sensors_timestamp *ts = &gyro_st->ts;
        ssize_t i, size;
        unsigned int no;

        /* parse all fifo packets */
        for (i = 0, no = 0; i < st->fifo.count; i += size, ++no) {
                struct inv_icm45600_gyro_buffer buffer = { };
                const struct inv_icm45600_fifo_sensor_data *accel, *gyro;
                const __le16 *timestamp;
                const s8 *temp;
                unsigned int odr;
                s64 ts_val;

                size = inv_icm45600_fifo_decode_packet(&st->fifo.data[i],
                                &accel, &gyro, &temp, &timestamp, &odr);
                /* quit if error or FIFO is empty */
                if (size <= 0)
                        return size;

                /* skip packet if no gyro data or data is invalid */
                if (gyro == NULL || !inv_icm45600_fifo_is_data_valid(gyro))
                        continue;

                /* update odr */
                if (odr & INV_ICM45600_SENSOR_GYRO)
                        inv_sensors_timestamp_apply_odr(ts, st->fifo.period,
                                                        st->fifo.nb.total, no);

                memcpy(&buffer.gyro, gyro, sizeof(buffer.gyro));
                /* convert 8 bits FIFO temperature in high resolution format */
                buffer.temp = temp ? (*temp * 64) : 0;
                ts_val = inv_sensors_timestamp_pop(ts);
                iio_push_to_buffers_with_ts(indio_dev, &buffer, sizeof(buffer), ts_val);
        }

        return 0;
}