// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2020 Invensense, Inc.
 */

#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/delay.h>
#include <linux/math64.h>
#include <linux/minmax.h>
#include <linux/units.h>

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

#include "inv_icm42600.h"
#include "inv_icm42600_temp.h"
#include "inv_icm42600_buffer.h"

#define INV_ICM42600_ACCEL_CHAN(_modifier, _index, _ext_info)           \
        {                                                               \
                .type = IIO_ACCEL,                                      \
                .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_BE,                           \
                },                                                      \
                .ext_info = _ext_info,                                  \
        }

#define INV_ICM42600_ACCEL_EVENT_CHAN(_modifier, _events, _events_nb)   \
        {                                                               \
                .type = IIO_ACCEL,                                      \
                .modified = 1,                                          \
                .channel2 = _modifier,                                  \
                .event_spec = _events,                                  \
                .num_event_specs = _events_nb,                          \
                .scan_index = -1,                                       \
        }

enum inv_icm42600_accel_scan {
        INV_ICM42600_ACCEL_SCAN_X,
        INV_ICM42600_ACCEL_SCAN_Y,
        INV_ICM42600_ACCEL_SCAN_Z,
        INV_ICM42600_ACCEL_SCAN_TEMP,
        INV_ICM42600_ACCEL_SCAN_TIMESTAMP,
};

static const char * const inv_icm42600_accel_power_mode_items[] = {
        "low-noise",
        "low-power",
};
static const int inv_icm42600_accel_power_mode_values[] = {
        INV_ICM42600_SENSOR_MODE_LOW_NOISE,
        INV_ICM42600_SENSOR_MODE_LOW_POWER,
};
static const int inv_icm42600_accel_filter_values[] = {
        INV_ICM42600_FILTER_BW_ODR_DIV_2,
        INV_ICM42600_FILTER_AVG_16X,
};

static int inv_icm42600_accel_power_mode_set(struct iio_dev *indio_dev,
                                             const struct iio_chan_spec *chan,
                                             unsigned int idx)
{
        struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
        struct inv_icm42600_sensor_state *accel_st = iio_priv(indio_dev);
        int power_mode, filter;

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

        if (idx >= ARRAY_SIZE(inv_icm42600_accel_power_mode_values))
                return -EINVAL;

        power_mode = inv_icm42600_accel_power_mode_values[idx];
        filter = inv_icm42600_accel_filter_values[idx];

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

        /* cannot change if accel sensor is on */
        if (st->conf.accel.mode != INV_ICM42600_SENSOR_MODE_OFF)
                return -EBUSY;

        /* prevent change if power mode is not supported by the ODR */
        switch (power_mode) {
        case INV_ICM42600_SENSOR_MODE_LOW_NOISE:
                if (st->conf.accel.odr >= INV_ICM42600_ODR_6_25HZ_LP &&
                    st->conf.accel.odr <= INV_ICM42600_ODR_1_5625HZ_LP)
                        return -EPERM;
                break;
        case INV_ICM42600_SENSOR_MODE_LOW_POWER:
        default:
                if (st->conf.accel.odr <= INV_ICM42600_ODR_1KHZ_LN)
                        return -EPERM;
                break;
        }

        accel_st->power_mode = power_mode;
        accel_st->filter = filter;

        return 0;
}

static int inv_icm42600_accel_power_mode_get(struct iio_dev *indio_dev,
                                             const struct iio_chan_spec *chan)
{
        struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
        struct inv_icm42600_sensor_state *accel_st = iio_priv(indio_dev);
        unsigned int idx;
        int power_mode;

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

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

        /* if sensor is on, returns actual power mode and not configured one */
        switch (st->conf.accel.mode) {
        case INV_ICM42600_SENSOR_MODE_LOW_POWER:
        case INV_ICM42600_SENSOR_MODE_LOW_NOISE:
                power_mode = st->conf.accel.mode;
                break;
        default:
                power_mode = accel_st->power_mode;
                break;
        }

        for (idx = 0; idx < ARRAY_SIZE(inv_icm42600_accel_power_mode_values); ++idx) {
                if (power_mode == inv_icm42600_accel_power_mode_values[idx])
                        break;
        }
        if (idx >= ARRAY_SIZE(inv_icm42600_accel_power_mode_values))
                return -EINVAL;

        return idx;
}

static const struct iio_enum inv_icm42600_accel_power_mode_enum = {
        .items = inv_icm42600_accel_power_mode_items,
        .num_items = ARRAY_SIZE(inv_icm42600_accel_power_mode_items),
        .set = inv_icm42600_accel_power_mode_set,
        .get = inv_icm42600_accel_power_mode_get,
};

static const struct iio_chan_spec_ext_info inv_icm42600_accel_ext_infos[] = {
        IIO_MOUNT_MATRIX(IIO_SHARED_BY_ALL, inv_icm42600_get_mount_matrix),
        IIO_ENUM_AVAILABLE("power_mode", IIO_SHARED_BY_TYPE,
                           &inv_icm42600_accel_power_mode_enum),
        IIO_ENUM("power_mode", IIO_SHARED_BY_TYPE,
                 &inv_icm42600_accel_power_mode_enum),
        { }
};

/* WoM event: rising ROC */
static const struct iio_event_spec inv_icm42600_wom_events[] = {
        {
                .type = IIO_EV_TYPE_ROC,
                .dir = IIO_EV_DIR_RISING,
                .mask_separate = BIT(IIO_EV_INFO_ENABLE) |
                                 BIT(IIO_EV_INFO_VALUE),
        },
};

static const struct iio_chan_spec inv_icm42600_accel_channels[] = {
        INV_ICM42600_ACCEL_CHAN(IIO_MOD_X, INV_ICM42600_ACCEL_SCAN_X,
                                inv_icm42600_accel_ext_infos),
        INV_ICM42600_ACCEL_CHAN(IIO_MOD_Y, INV_ICM42600_ACCEL_SCAN_Y,
                                inv_icm42600_accel_ext_infos),
        INV_ICM42600_ACCEL_CHAN(IIO_MOD_Z, INV_ICM42600_ACCEL_SCAN_Z,
                                inv_icm42600_accel_ext_infos),
        INV_ICM42600_TEMP_CHAN(INV_ICM42600_ACCEL_SCAN_TEMP),
        IIO_CHAN_SOFT_TIMESTAMP(INV_ICM42600_ACCEL_SCAN_TIMESTAMP),
        INV_ICM42600_ACCEL_EVENT_CHAN(IIO_MOD_X_OR_Y_OR_Z, inv_icm42600_wom_events,
                                      ARRAY_SIZE(inv_icm42600_wom_events)),
};

/*
 * IIO buffer data: size must be a power of 2 and timestamp aligned
 * 16 bytes: 6 bytes acceleration, 2 bytes temperature, 8 bytes timestamp
 */
struct inv_icm42600_accel_buffer {
        struct inv_icm42600_fifo_sensor_data accel;
        s16 temp;
        aligned_s64 timestamp;
};

#define INV_ICM42600_SCAN_MASK_ACCEL_3AXIS                              \
        (BIT(INV_ICM42600_ACCEL_SCAN_X) |                               \
        BIT(INV_ICM42600_ACCEL_SCAN_Y) |                                \
        BIT(INV_ICM42600_ACCEL_SCAN_Z))

#define INV_ICM42600_SCAN_MASK_TEMP     BIT(INV_ICM42600_ACCEL_SCAN_TEMP)

static const unsigned long inv_icm42600_accel_scan_masks[] = {
        /* 3-axis accel + temperature */
        INV_ICM42600_SCAN_MASK_ACCEL_3AXIS | INV_ICM42600_SCAN_MASK_TEMP,
        0,
};

/* enable accelerometer sensor and FIFO write */
static int inv_icm42600_accel_update_scan_mode(struct iio_dev *indio_dev,
                                               const unsigned long *scan_mask)
{
        struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
        struct inv_icm42600_sensor_state *accel_st = iio_priv(indio_dev);
        struct inv_icm42600_sensor_conf conf = INV_ICM42600_SENSOR_CONF_INIT;
        unsigned int fifo_en = 0;
        unsigned int sleep_temp = 0;
        unsigned int sleep_accel = 0;
        unsigned int sleep;
        int ret;

        mutex_lock(&st->lock);

        if (*scan_mask & INV_ICM42600_SCAN_MASK_TEMP) {
                /* enable temp sensor */
                ret = inv_icm42600_set_temp_conf(st, true, &sleep_temp);
                if (ret)
                        goto out_unlock;
                fifo_en |= INV_ICM42600_SENSOR_TEMP;
        }

        if (*scan_mask & INV_ICM42600_SCAN_MASK_ACCEL_3AXIS) {
                /* enable accel sensor */
                conf.mode = accel_st->power_mode;
                conf.filter = accel_st->filter;
                ret = inv_icm42600_set_accel_conf(st, &conf, &sleep_accel);
                if (ret)
                        goto out_unlock;
                fifo_en |= INV_ICM42600_SENSOR_ACCEL;
        }

        /* update data FIFO write */
        ret = inv_icm42600_buffer_set_fifo_en(st, fifo_en | st->fifo.en);

out_unlock:
        mutex_unlock(&st->lock);
        /* sleep maximum required time */
        sleep = max(sleep_accel, sleep_temp);
        if (sleep)
                msleep(sleep);
        return ret;
}

static int inv_icm42600_accel_read_sensor(struct iio_dev *indio_dev,
                                          struct iio_chan_spec const *chan,
                                          s16 *val)
{
        struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
        struct inv_icm42600_sensor_state *accel_st = iio_priv(indio_dev);
        struct device *dev = regmap_get_device(st->map);
        struct inv_icm42600_sensor_conf conf = INV_ICM42600_SENSOR_CONF_INIT;
        unsigned int reg;
        __be16 *data;
        int ret;

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

        switch (chan->channel2) {
        case IIO_MOD_X:
                reg = INV_ICM42600_REG_ACCEL_DATA_X;
                break;
        case IIO_MOD_Y:
                reg = INV_ICM42600_REG_ACCEL_DATA_Y;
                break;
        case IIO_MOD_Z:
                reg = INV_ICM42600_REG_ACCEL_DATA_Z;
                break;
        default:
                return -EINVAL;
        }

        pm_runtime_get_sync(dev);
        mutex_lock(&st->lock);

        /* enable accel sensor */
        conf.mode = accel_st->power_mode;
        conf.filter = accel_st->filter;
        ret = inv_icm42600_set_accel_conf(st, &conf, NULL);
        if (ret)
                goto exit;

        /* read accel register data */
        data = (__be16 *)&st->buffer[0];
        ret = regmap_bulk_read(st->map, reg, data, sizeof(*data));
        if (ret)
                goto exit;

        *val = (s16)be16_to_cpup(data);
        if (*val == INV_ICM42600_DATA_INVALID)
                ret = -EINVAL;
exit:
        mutex_unlock(&st->lock);
        pm_runtime_put_autosuspend(dev);
        return ret;
}

static unsigned int inv_icm42600_accel_convert_roc_to_wom(u64 roc,
                                                          int accel_hz, int accel_uhz)
{
        /* 1000/256mg per LSB converted in µm/s² */
        const unsigned int convert = (9807U * (MICRO / MILLI)) / 256U;
        u64 value;
        u64 freq_uhz;

        /* return 0 only if roc is 0 */
        if (roc == 0)
                return 0;

        freq_uhz = (u64)accel_hz * MICRO + (u64)accel_uhz;
        value = div64_u64(roc * MICRO, freq_uhz * (u64)convert);

        /* limit value to 8 bits and prevent 0 */
        return clamp(value, 1, 255);
}

static u64 inv_icm42600_accel_convert_wom_to_roc(unsigned int threshold,
                                                 int accel_hz, int accel_uhz)
{
        /* 1000/256mg per LSB converted in µm/s² */
        const unsigned int convert = (9807U * (MICRO / MILLI)) / 256U;
        u64 value;
        u64 freq_uhz;

        value = threshold * convert;
        freq_uhz = (u64)accel_hz * MICRO + (u64)accel_uhz;

        /* compute the differential by multiplying by the frequency */
        return div_u64(value * freq_uhz, MICRO);
}

static int inv_icm42600_accel_set_wom_threshold(struct inv_icm42600_state *st,
                                                u64 value,
                                                int accel_hz, int accel_uhz)
{
        unsigned int threshold;
        int ret;

        /* convert roc to wom threshold and convert back to handle clipping */
        threshold = inv_icm42600_accel_convert_roc_to_wom(value, accel_hz, accel_uhz);
        value = inv_icm42600_accel_convert_wom_to_roc(threshold, accel_hz, accel_uhz);

        dev_dbg(regmap_get_device(st->map), "wom_threshold: 0x%x\n", threshold);

        /* set accel WoM threshold for the 3 axes */
        st->buffer[0] = threshold;
        st->buffer[1] = threshold;
        st->buffer[2] = threshold;
        ret = regmap_bulk_write(st->map, INV_ICM42600_REG_ACCEL_WOM_X_THR, st->buffer, 3);
        if (ret)
                return ret;

        st->apex.wom.value = value;

        return 0;
}

static int _inv_icm42600_accel_enable_wom(struct iio_dev *indio_dev)
{
        struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
        struct inv_icm42600_sensor_state *accel_st = iio_priv(indio_dev);
        struct inv_icm42600_sensor_conf conf = INV_ICM42600_SENSOR_CONF_INIT;
        unsigned int sleep_ms = 0;
        int ret;

        scoped_guard(mutex, &st->lock) {
                /* turn on accel sensor */
                conf.mode = accel_st->power_mode;
                conf.filter = accel_st->filter;
                ret = inv_icm42600_set_accel_conf(st, &conf, &sleep_ms);
                if (ret)
                        return ret;
        }

        if (sleep_ms)
                msleep(sleep_ms);

        scoped_guard(mutex, &st->lock) {
                ret = inv_icm42600_enable_wom(st);
                if (ret)
                        return ret;
                st->apex.on++;
                st->apex.wom.enable = true;
        }

        return 0;
}

static int inv_icm42600_accel_enable_wom(struct iio_dev *indio_dev)
{
        struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
        struct device *pdev = regmap_get_device(st->map);
        int ret;

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

        ret = _inv_icm42600_accel_enable_wom(indio_dev);
        if (ret) {
                pm_runtime_mark_last_busy(pdev);
                pm_runtime_put_autosuspend(pdev);
                return ret;
        }

        return 0;
}

static int _inv_icm42600_accel_disable_wom(struct iio_dev *indio_dev)
{
        struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
        struct inv_icm42600_sensor_conf conf = INV_ICM42600_SENSOR_CONF_INIT;
        unsigned int sleep_ms = 0;
        int ret;

        scoped_guard(mutex, &st->lock) {
                /*
                 * Consider that turning off WoM is always working to avoid
                 * blocking the chip in on mode and prevent going back to sleep.
                 * If there is an error, the chip will anyway go back to sleep
                 * and the feature will not work anymore.
                 */
                st->apex.wom.enable = false;
                st->apex.on--;
                ret = inv_icm42600_disable_wom(st);
                if (ret)
                        return ret;
                /* turn off accel sensor if not used */
                if (!st->apex.on && !iio_buffer_enabled(indio_dev)) {
                        conf.mode = INV_ICM42600_SENSOR_MODE_OFF;
                        ret = inv_icm42600_set_accel_conf(st, &conf, &sleep_ms);
                        if (ret)
                                return ret;
                }
        }

        if (sleep_ms)
                msleep(sleep_ms);

        return 0;
}

static int inv_icm42600_accel_disable_wom(struct iio_dev *indio_dev)
{
        struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
        struct device *pdev = regmap_get_device(st->map);
        int ret;

        ret = _inv_icm42600_accel_disable_wom(indio_dev);

        pm_runtime_mark_last_busy(pdev);
        pm_runtime_put_autosuspend(pdev);

        return ret;
}

void inv_icm42600_accel_handle_events(struct iio_dev *indio_dev,
                                      unsigned int status2, unsigned int status3,
                                      s64 timestamp)
{
        struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
        u64 ev_code;

        /* handle WoM event */
        if (st->apex.wom.enable && (status2 & INV_ICM42600_INT_STATUS2_WOM_INT)) {
                ev_code = IIO_MOD_EVENT_CODE(IIO_ACCEL, 0, IIO_MOD_X_OR_Y_OR_Z,
                                             IIO_EV_TYPE_ROC, IIO_EV_DIR_RISING);
                iio_push_event(indio_dev, ev_code, timestamp);
        }
}

/* IIO format int + nano */
static const int inv_icm42600_accel_scale[] = {
        /* +/- 16G => 0.004788403 m/s-2 */
        [2 * INV_ICM42600_ACCEL_FS_16G] = 0,
        [2 * INV_ICM42600_ACCEL_FS_16G + 1] = 4788403,
        /* +/- 8G => 0.002394202 m/s-2 */
        [2 * INV_ICM42600_ACCEL_FS_8G] = 0,
        [2 * INV_ICM42600_ACCEL_FS_8G + 1] = 2394202,
        /* +/- 4G => 0.001197101 m/s-2 */
        [2 * INV_ICM42600_ACCEL_FS_4G] = 0,
        [2 * INV_ICM42600_ACCEL_FS_4G + 1] = 1197101,
        /* +/- 2G => 0.000598550 m/s-2 */
        [2 * INV_ICM42600_ACCEL_FS_2G] = 0,
        [2 * INV_ICM42600_ACCEL_FS_2G + 1] = 598550,
};
static const int inv_icm42686_accel_scale[] = {
        /* +/- 32G => 0.009576807 m/s-2 */
        [2 * INV_ICM42686_ACCEL_FS_32G] = 0,
        [2 * INV_ICM42686_ACCEL_FS_32G + 1] = 9576807,
        /* +/- 16G => 0.004788403 m/s-2 */
        [2 * INV_ICM42686_ACCEL_FS_16G] = 0,
        [2 * INV_ICM42686_ACCEL_FS_16G + 1] = 4788403,
        /* +/- 8G => 0.002394202 m/s-2 */
        [2 * INV_ICM42686_ACCEL_FS_8G] = 0,
        [2 * INV_ICM42686_ACCEL_FS_8G + 1] = 2394202,
        /* +/- 4G => 0.001197101 m/s-2 */
        [2 * INV_ICM42686_ACCEL_FS_4G] = 0,
        [2 * INV_ICM42686_ACCEL_FS_4G + 1] = 1197101,
        /* +/- 2G => 0.000598550 m/s-2 */
        [2 * INV_ICM42686_ACCEL_FS_2G] = 0,
        [2 * INV_ICM42686_ACCEL_FS_2G + 1] = 598550,
};

static int inv_icm42600_accel_read_scale(struct iio_dev *indio_dev,
                                         int *val, int *val2)
{
        struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
        struct inv_icm42600_sensor_state *accel_st = iio_priv(indio_dev);
        unsigned int idx;

        idx = st->conf.accel.fs;

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

static int inv_icm42600_accel_write_scale(struct iio_dev *indio_dev,
                                          int val, int val2)
{
        struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
        struct inv_icm42600_sensor_state *accel_st = iio_priv(indio_dev);
        struct device *dev = regmap_get_device(st->map);
        unsigned int idx;
        struct inv_icm42600_sensor_conf conf = INV_ICM42600_SENSOR_CONF_INIT;
        int ret;

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

        conf.fs = idx / 2;

        pm_runtime_get_sync(dev);

        scoped_guard(mutex, &st->lock)
                ret = inv_icm42600_set_accel_conf(st, &conf, NULL);

        pm_runtime_put_autosuspend(dev);

        return ret;
}

/* IIO format int + micro */
static const int inv_icm42600_accel_odr[] = {
        /* 1.5625Hz */
        1, 562500,
        /* 3.125Hz */
        3, 125000,
        /* 6.25Hz */
        6, 250000,
        /* 12.5Hz */
        12, 500000,
        /* 25Hz */
        25, 0,
        /* 50Hz */
        50, 0,
        /* 100Hz */
        100, 0,
        /* 200Hz */
        200, 0,
        /* 1kHz */
        1000, 0,
        /* 2kHz */
        2000, 0,
        /* 4kHz */
        4000, 0,
};

static const int inv_icm42600_accel_odr_conv[] = {
        INV_ICM42600_ODR_1_5625HZ_LP,
        INV_ICM42600_ODR_3_125HZ_LP,
        INV_ICM42600_ODR_6_25HZ_LP,
        INV_ICM42600_ODR_12_5HZ,
        INV_ICM42600_ODR_25HZ,
        INV_ICM42600_ODR_50HZ,
        INV_ICM42600_ODR_100HZ,
        INV_ICM42600_ODR_200HZ,
        INV_ICM42600_ODR_1KHZ_LN,
        INV_ICM42600_ODR_2KHZ_LN,
        INV_ICM42600_ODR_4KHZ_LN,
};

static int inv_icm42600_accel_read_odr(struct inv_icm42600_state *st,
                                       int *val, int *val2)
{
        unsigned int odr;
        unsigned int i;

        odr = st->conf.accel.odr;

        for (i = 0; i < ARRAY_SIZE(inv_icm42600_accel_odr_conv); ++i) {
                if (inv_icm42600_accel_odr_conv[i] == odr)
                        break;
        }
        if (i >= ARRAY_SIZE(inv_icm42600_accel_odr_conv))
                return -EINVAL;

        *val = inv_icm42600_accel_odr[2 * i];
        *val2 = inv_icm42600_accel_odr[2 * i + 1];

        return IIO_VAL_INT_PLUS_MICRO;
}

static int inv_icm42600_accel_write_odr(struct iio_dev *indio_dev,
                                        int val, int val2)
{
        struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
        struct inv_icm42600_sensor_state *accel_st = iio_priv(indio_dev);
        struct inv_sensors_timestamp *ts = &accel_st->ts;
        struct device *dev = regmap_get_device(st->map);
        unsigned int idx;
        struct inv_icm42600_sensor_conf conf = INV_ICM42600_SENSOR_CONF_INIT;
        int ret;

        for (idx = 0; idx < ARRAY_SIZE(inv_icm42600_accel_odr); idx += 2) {
                if (val == inv_icm42600_accel_odr[idx] &&
                    val2 == inv_icm42600_accel_odr[idx + 1])
                        break;
        }
        if (idx >= ARRAY_SIZE(inv_icm42600_accel_odr))
                return -EINVAL;

        conf.odr = inv_icm42600_accel_odr_conv[idx / 2];
        if (conf.odr == st->conf.accel.odr)
                return 0;

        pm_runtime_get_sync(dev);
        mutex_lock(&st->lock);

        ret = inv_sensors_timestamp_update_odr(ts, inv_icm42600_odr_to_period(conf.odr),
                                               iio_buffer_enabled(indio_dev));
        if (ret)
                goto out_unlock;

        ret = inv_icm42600_set_accel_conf(st, &conf, NULL);
        if (ret)
                goto out_unlock;
        /* update wom threshold since roc is dependent on sampling frequency */
        ret = inv_icm42600_accel_set_wom_threshold(st, st->apex.wom.value, val, val2);
        if (ret)
                goto out_unlock;
        inv_icm42600_buffer_update_fifo_period(st);
        inv_icm42600_buffer_update_watermark(st);

out_unlock:
        mutex_unlock(&st->lock);
        pm_runtime_put_autosuspend(dev);

        return ret;
}

/*
 * Calibration bias values, IIO range format int + micro.
 * Value is limited to +/-1g coded on 12 bits signed. Step is 0.5mg.
 */
static int inv_icm42600_accel_calibbias[] = {
        -10, 42010,             /* min: -10.042010 m/s² */
        0, 4903,                /* step: 0.004903 m/s² */
        10, 37106,              /* max: 10.037106 m/s² */
};

static int inv_icm42600_accel_read_offset(struct inv_icm42600_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;
        u8 data[2];
        int ret;

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

        switch (chan->channel2) {
        case IIO_MOD_X:
                reg = INV_ICM42600_REG_OFFSET_USER4;
                break;
        case IIO_MOD_Y:
                reg = INV_ICM42600_REG_OFFSET_USER6;
                break;
        case IIO_MOD_Z:
                reg = INV_ICM42600_REG_OFFSET_USER7;
                break;
        default:
                return -EINVAL;
        }

        pm_runtime_get_sync(dev);
        mutex_lock(&st->lock);

        ret = regmap_bulk_read(st->map, reg, st->buffer, sizeof(data));
        memcpy(data, st->buffer, sizeof(data));

        mutex_unlock(&st->lock);
        pm_runtime_put_autosuspend(dev);
        if (ret)
                return ret;

        /* 12 bits signed value */
        switch (chan->channel2) {
        case IIO_MOD_X:
                offset = sign_extend32(((data[0] & 0xF0) << 4) | data[1], 11);
                break;
        case IIO_MOD_Y:
                offset = sign_extend32(((data[1] & 0x0F) << 8) | data[0], 11);
                break;
        case IIO_MOD_Z:
                offset = sign_extend32(((data[0] & 0xF0) << 4) | data[1], 11);
                break;
        default:
                return -EINVAL;
        }

        /*
         * convert raw offset to g then to m/s²
         * 12 bits signed raw step 0.5mg to g: 5 / 10000
         * g to m/s²: 9.806650
         * result in micro (1000000)
         * (offset * 5 * 9.806650 * 1000000) / 10000
         */
        val64 = (s64)offset * 5LL * 9806650LL;
        /* for rounding, add + or - divisor (10000) divided by 2 */
        if (val64 >= 0)
                val64 += 10000LL / 2LL;
        else
                val64 -= 10000LL / 2LL;
        bias = div_s64(val64, 10000L);
        *val = bias / 1000000L;
        *val2 = bias % 1000000L;

        return IIO_VAL_INT_PLUS_MICRO;
}

static int inv_icm42600_accel_write_offset(struct inv_icm42600_state *st,
                                           struct iio_chan_spec const *chan,
                                           int val, int val2)
{
        struct device *dev = regmap_get_device(st->map);
        s64 val64;
        s32 min, max;
        unsigned int reg, regval;
        s16 offset;
        int ret;

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

        switch (chan->channel2) {
        case IIO_MOD_X:
                reg = INV_ICM42600_REG_OFFSET_USER4;
                break;
        case IIO_MOD_Y:
                reg = INV_ICM42600_REG_OFFSET_USER6;
                break;
        case IIO_MOD_Z:
                reg = INV_ICM42600_REG_OFFSET_USER7;
                break;
        default:
                return -EINVAL;
        }

        /* inv_icm42600_accel_calibbias: min - step - max in micro */
        min = inv_icm42600_accel_calibbias[0] * 1000000L +
              inv_icm42600_accel_calibbias[1];
        max = inv_icm42600_accel_calibbias[4] * 1000000L +
              inv_icm42600_accel_calibbias[5];
        val64 = (s64)val * 1000000LL + (s64)val2;
        if (val64 < min || val64 > max)
                return -EINVAL;

        /*
         * convert m/s² to g then to raw value
         * m/s² to g: 1 / 9.806650
         * g to raw 12 bits signed, step 0.5mg: 10000 / 5
         * val in micro (1000000)
         * val * 10000 / (9.806650 * 1000000 * 5)
         */
        val64 = val64 * 10000LL;
        /* for rounding, add + or - divisor (9806650 * 5) divided by 2 */
        if (val64 >= 0)
                val64 += 9806650 * 5 / 2;
        else
                val64 -= 9806650 * 5 / 2;
        offset = div_s64(val64, 9806650 * 5);

        /* clamp value limited to 12 bits signed */
        if (offset < -2048)
                offset = -2048;
        else if (offset > 2047)
                offset = 2047;

        pm_runtime_get_sync(dev);
        mutex_lock(&st->lock);

        switch (chan->channel2) {
        case IIO_MOD_X:
                /* OFFSET_USER4 register is shared */
                ret = regmap_read(st->map, INV_ICM42600_REG_OFFSET_USER4,
                                  &regval);
                if (ret)
                        goto out_unlock;
                st->buffer[0] = ((offset & 0xF00) >> 4) | (regval & 0x0F);
                st->buffer[1] = offset & 0xFF;
                break;
        case IIO_MOD_Y:
                /* OFFSET_USER7 register is shared */
                ret = regmap_read(st->map, INV_ICM42600_REG_OFFSET_USER7,
                                  &regval);
                if (ret)
                        goto out_unlock;
                st->buffer[0] = offset & 0xFF;
                st->buffer[1] = ((offset & 0xF00) >> 8) | (regval & 0xF0);
                break;
        case IIO_MOD_Z:
                /* OFFSET_USER7 register is shared */
                ret = regmap_read(st->map, INV_ICM42600_REG_OFFSET_USER7,
                                  &regval);
                if (ret)
                        goto out_unlock;
                st->buffer[0] = ((offset & 0xF00) >> 4) | (regval & 0x0F);
                st->buffer[1] = offset & 0xFF;
                break;
        default:
                ret = -EINVAL;
                goto out_unlock;
        }

        ret = regmap_bulk_write(st->map, reg, st->buffer, 2);

out_unlock:
        mutex_unlock(&st->lock);
        pm_runtime_put_autosuspend(dev);
        return ret;
}

static int inv_icm42600_accel_read_raw(struct iio_dev *indio_dev,
                                       struct iio_chan_spec const *chan,
                                       int *val, int *val2, long mask)
{
        struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
        s16 data;
        int ret;

        switch (chan->type) {
        case IIO_ACCEL:
                break;
        case IIO_TEMP:
                return inv_icm42600_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_icm42600_accel_read_sensor(indio_dev, chan, &data);
                iio_device_release_direct(indio_dev);
                if (ret)
                        return ret;
                *val = data;
                return IIO_VAL_INT;
        case IIO_CHAN_INFO_SCALE:
                return inv_icm42600_accel_read_scale(indio_dev, val, val2);
        case IIO_CHAN_INFO_SAMP_FREQ:
                return inv_icm42600_accel_read_odr(st, val, val2);
        case IIO_CHAN_INFO_CALIBBIAS:
                return inv_icm42600_accel_read_offset(st, chan, val, val2);
        default:
                return -EINVAL;
        }
}

static int inv_icm42600_accel_read_avail(struct iio_dev *indio_dev,
                                         struct iio_chan_spec const *chan,
                                         const int **vals,
                                         int *type, int *length, long mask)
{
        struct inv_icm42600_sensor_state *accel_st = iio_priv(indio_dev);

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

        switch (mask) {
        case IIO_CHAN_INFO_SCALE:
                *vals = accel_st->scales;
                *type = IIO_VAL_INT_PLUS_NANO;
                *length = accel_st->scales_len;
                return IIO_AVAIL_LIST;
        case IIO_CHAN_INFO_SAMP_FREQ:
                *vals = inv_icm42600_accel_odr;
                *type = IIO_VAL_INT_PLUS_MICRO;
                *length = ARRAY_SIZE(inv_icm42600_accel_odr);
                return IIO_AVAIL_LIST;
        case IIO_CHAN_INFO_CALIBBIAS:
                *vals = inv_icm42600_accel_calibbias;
                *type = IIO_VAL_INT_PLUS_MICRO;
                return IIO_AVAIL_RANGE;
        default:
                return -EINVAL;
        }
}

static int inv_icm42600_accel_write_raw(struct iio_dev *indio_dev,
                                        struct iio_chan_spec const *chan,
                                        int val, int val2, long mask)
{
        struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
        int ret;

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

        switch (mask) {
        case IIO_CHAN_INFO_SCALE:
                if (!iio_device_claim_direct(indio_dev))
                        return -EBUSY;
                ret = inv_icm42600_accel_write_scale(indio_dev, val, val2);
                iio_device_release_direct(indio_dev);
                return ret;
        case IIO_CHAN_INFO_SAMP_FREQ:
                return inv_icm42600_accel_write_odr(indio_dev, val, val2);
        case IIO_CHAN_INFO_CALIBBIAS:
                if (!iio_device_claim_direct(indio_dev))
                        return -EBUSY;
                ret = inv_icm42600_accel_write_offset(st, chan, val, val2);
                iio_device_release_direct(indio_dev);
                return ret;
        default:
                return -EINVAL;
        }
}

static int inv_icm42600_accel_write_raw_get_fmt(struct iio_dev *indio_dev,
                                                struct iio_chan_spec const *chan,
                                                long mask)
{
        if (chan->type != IIO_ACCEL)
                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_MICRO;
        default:
                return -EINVAL;
        }
}

static int inv_icm42600_accel_hwfifo_set_watermark(struct iio_dev *indio_dev,
                                                   unsigned int val)
{
        struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);

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

        st->fifo.watermark.accel = val;
        return inv_icm42600_buffer_update_watermark(st);
}

static int inv_icm42600_accel_hwfifo_flush(struct iio_dev *indio_dev,
                                           unsigned int count)
{
        struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
        int ret;

        if (count == 0)
                return 0;

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

        ret = inv_icm42600_buffer_hwfifo_flush(st, count);
        if (ret)
                return ret;

        return st->fifo.nb.accel;
}

static int inv_icm42600_accel_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 inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);

        /* handle only WoM (roc rising) event */
        if (type != IIO_EV_TYPE_ROC || dir != IIO_EV_DIR_RISING)
                return -EINVAL;

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

        return st->apex.wom.enable ? 1 : 0;
}

static int inv_icm42600_accel_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 inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);

        /* handle only WoM (roc rising) event */
        if (type != IIO_EV_TYPE_ROC || dir != IIO_EV_DIR_RISING)
                return -EINVAL;

        scoped_guard(mutex, &st->lock) {
                if (st->apex.wom.enable == state)
                        return 0;
        }

        if (state)
                return inv_icm42600_accel_enable_wom(indio_dev);

        return inv_icm42600_accel_disable_wom(indio_dev);
}

static int inv_icm42600_accel_read_event_value(struct iio_dev *indio_dev,
                                               const struct iio_chan_spec *chan,
                                               enum iio_event_type type,
                                               enum iio_event_direction dir,
                                               enum iio_event_info info,
                                               int *val, int *val2)
{
        struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
        u32 rem;

        /* handle only WoM (roc rising) event value */
        if (type != IIO_EV_TYPE_ROC || dir != IIO_EV_DIR_RISING)
                return -EINVAL;

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

        /* return value in micro */
        *val = div_u64_rem(st->apex.wom.value, MICRO, &rem);
        *val2 = rem;
        return IIO_VAL_INT_PLUS_MICRO;
}

static int _inv_icm42600_accel_wom_value(struct inv_icm42600_state *st,
                                         int val, int val2)
{
        u64 value;
        unsigned int accel_hz, accel_uhz;
        int ret;

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

        ret = inv_icm42600_accel_read_odr(st, &accel_hz, &accel_uhz);
        if (ret < 0)
                return ret;

        value = (u64)val * MICRO + (u64)val2;

        return inv_icm42600_accel_set_wom_threshold(st, value,
                                                    accel_hz, accel_uhz);
}

static int inv_icm42600_accel_write_event_value(struct iio_dev *indio_dev,
                                                const struct iio_chan_spec *chan,
                                                enum iio_event_type type,
                                                enum iio_event_direction dir,
                                                enum iio_event_info info,
                                                int val, int val2)
{
        struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
        struct device *dev = regmap_get_device(st->map);
        int ret;

        /* handle only WoM (roc rising) event value */
        if (type != IIO_EV_TYPE_ROC || dir != IIO_EV_DIR_RISING)
                return -EINVAL;

        if (val < 0 || val2 < 0)
                return -EINVAL;

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

        ret = _inv_icm42600_accel_wom_value(st, val, val2);

        pm_runtime_mark_last_busy(dev);
        pm_runtime_put_autosuspend(dev);

        return ret;
}

static const struct iio_info inv_icm42600_accel_info = {
        .read_raw = inv_icm42600_accel_read_raw,
        .read_avail = inv_icm42600_accel_read_avail,
        .write_raw = inv_icm42600_accel_write_raw,
        .write_raw_get_fmt = inv_icm42600_accel_write_raw_get_fmt,
        .debugfs_reg_access = inv_icm42600_debugfs_reg,
        .update_scan_mode = inv_icm42600_accel_update_scan_mode,
        .hwfifo_set_watermark = inv_icm42600_accel_hwfifo_set_watermark,
        .hwfifo_flush_to_buffer = inv_icm42600_accel_hwfifo_flush,
        .read_event_config = inv_icm42600_accel_read_event_config,
        .write_event_config = inv_icm42600_accel_write_event_config,
        .read_event_value = inv_icm42600_accel_read_event_value,
        .write_event_value = inv_icm42600_accel_write_event_value,
};

struct iio_dev *inv_icm42600_accel_init(struct inv_icm42600_state *st)
{
        struct device *dev = regmap_get_device(st->map);
        const char *name;
        struct inv_icm42600_sensor_state *accel_st;
        struct inv_sensors_timestamp_chip ts_chip;
        struct iio_dev *indio_dev;
        int ret;

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

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

        switch (st->chip) {
        case INV_CHIP_ICM42686:
                accel_st->scales = inv_icm42686_accel_scale;
                accel_st->scales_len = ARRAY_SIZE(inv_icm42686_accel_scale);
                break;
        default:
                accel_st->scales = inv_icm42600_accel_scale;
                accel_st->scales_len = ARRAY_SIZE(inv_icm42600_accel_scale);
                break;
        }
        /* low-power by default at init */
        accel_st->power_mode = INV_ICM42600_SENSOR_MODE_LOW_POWER;
        accel_st->filter = INV_ICM42600_FILTER_AVG_16X;

        /*
         * 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_icm42600_odr_to_period(st->conf.accel.odr);
        inv_sensors_timestamp_init(&accel_st->ts, &ts_chip);

        iio_device_set_drvdata(indio_dev, st);
        indio_dev->name = name;
        indio_dev->info = &inv_icm42600_accel_info;
        indio_dev->modes = INDIO_DIRECT_MODE;
        indio_dev->channels = inv_icm42600_accel_channels;
        indio_dev->num_channels = ARRAY_SIZE(inv_icm42600_accel_channels);
        indio_dev->available_scan_masks = inv_icm42600_accel_scan_masks;

        ret = devm_iio_kfifo_buffer_setup(dev, indio_dev,
                                          &inv_icm42600_buffer_ops);
        if (ret)
                return ERR_PTR(ret);

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

        /* accel events are wakeup capable */
        ret = devm_device_init_wakeup(&indio_dev->dev);
        if (ret)
                return ERR_PTR(ret);

        return indio_dev;
}

int inv_icm42600_accel_parse_fifo(struct iio_dev *indio_dev)
{
        struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
        struct inv_icm42600_sensor_state *accel_st = iio_priv(indio_dev);
        struct inv_sensors_timestamp *ts = &accel_st->ts;
        ssize_t i, size;
        unsigned int no;
        const void *accel, *gyro, *timestamp;
        const int8_t *temp;
        unsigned int odr;
        int64_t ts_val;
        /* buffer is copied to userspace, zeroing it to avoid any data leak */
        struct inv_icm42600_accel_buffer buffer = { };

        /* parse all fifo packets */
        for (i = 0, no = 0; i < st->fifo.count; i += size, ++no) {
                size = inv_icm42600_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 accel data or data is invalid */
                if (accel == NULL || !inv_icm42600_fifo_is_data_valid(accel))
                        continue;

                /* update odr */
                if (odr & INV_ICM42600_SENSOR_ACCEL)
                        inv_sensors_timestamp_apply_odr(ts, st->fifo.period,
                                                        st->fifo.nb.total, no);

                memcpy(&buffer.accel, accel, sizeof(buffer.accel));
                /* 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_timestamp(indio_dev, &buffer, ts_val);
        }

        return 0;
}