/*
 * STMicroelectronics st_lsm6dsx i2c controller driver
 *
 * i2c controller embedded in lsm6dx series can connect up to four
 * slave devices using accelerometer sensor as trigger for i2c
 * read/write operations. Current implementation relies on SLV0 channel
 * for slave configuration and SLV{1,2,3} to read data and push them into
 * the hw FIFO
 *
 * Copyright (C) 2018 Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 */
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/bitfield.h>

#include "st_lsm6dsx.h"

#define ST_LSM6DSX_SLV_ADDR(n, base)            ((base) + (n) * 3)
#define ST_LSM6DSX_SLV_SUB_ADDR(n, base)        ((base) + 1 + (n) * 3)
#define ST_LSM6DSX_SLV_CONFIG(n, base)          ((base) + 2 + (n) * 3)

#define ST_LS6DSX_READ_OP_MASK                  GENMASK(2, 0)

static const struct st_lsm6dsx_ext_dev_settings st_lsm6dsx_ext_dev_table[] = {
        /* LIS2MDL */
        {
                .i2c_addr = { 0x1e },
                .wai = {
                        .addr = 0x4f,
                        .val = 0x40,
                },
                .id = ST_LSM6DSX_ID_MAGN,
                .odr_table = {
                        .reg = {
                                .addr = 0x60,
                                .mask = GENMASK(3, 2),
                        },
                        .odr_avl[0] = {  10000, 0x0 },
                        .odr_avl[1] = {  20000, 0x1 },
                        .odr_avl[2] = {  50000, 0x2 },
                        .odr_avl[3] = { 100000, 0x3 },
                        .odr_len = 4,
                },
                .fs_table = {
                        .fs_avl[0] = {
                                .gain = 1500,
                                .val = 0x0,
                        }, /* 1500 uG/LSB */
                        .fs_len = 1,
                },
                .temp_comp = {
                        .addr = 0x60,
                        .mask = BIT(7),
                },
                .pwr_table = {
                        .reg = {
                                .addr = 0x60,
                                .mask = GENMASK(1, 0),
                        },
                        .off_val = 0x2,
                        .on_val = 0x0,
                },
                .off_canc = {
                        .addr = 0x61,
                        .mask = BIT(1),
                },
                .bdu = {
                        .addr = 0x62,
                        .mask = BIT(4),
                },
                .out = {
                        .addr = 0x68,
                        .len = 6,
                },
        },
        /* LIS3MDL */
        {
                .i2c_addr = { 0x1e },
                .wai = {
                        .addr = 0x0f,
                        .val = 0x3d,
                },
                .id = ST_LSM6DSX_ID_MAGN,
                .odr_table = {
                        .reg = {
                                .addr = 0x20,
                                .mask = GENMASK(4, 2),
                        },
                        .odr_avl[0] = {  1000, 0x0 },
                        .odr_avl[1] = {  2000, 0x1 },
                        .odr_avl[2] = {  3000, 0x2 },
                        .odr_avl[3] = {  5000, 0x3 },
                        .odr_avl[4] = { 10000, 0x4 },
                        .odr_avl[5] = { 20000, 0x5 },
                        .odr_avl[6] = { 40000, 0x6 },
                        .odr_avl[7] = { 80000, 0x7 },
                        .odr_len = 8,
                },
                .fs_table = {
                        .reg = {
                                .addr = 0x21,
                                .mask = GENMASK(6, 5),
                        },
                        .fs_avl[0] = {
                                .gain = 146,
                                .val = 0x00,
                        }, /* 4000 uG/LSB */
                        .fs_avl[1] = {
                                .gain = 292,
                                .val = 0x01,
                        }, /* 8000 uG/LSB */
                        .fs_avl[2] = {
                                .gain = 438,
                                .val = 0x02,
                        }, /* 12000 uG/LSB */
                        .fs_avl[3] = {
                                .gain = 584,
                                .val = 0x03,
                        }, /* 16000 uG/LSB */
                        .fs_len = 4,
                },
                .pwr_table = {
                        .reg = {
                                .addr = 0x22,
                                .mask = GENMASK(1, 0),
                        },
                        .off_val = 0x2,
                        .on_val = 0x0,
                },
                .bdu = {
                        .addr = 0x24,
                        .mask = BIT(6),
                },
                .out = {
                        .addr = 0x28,
                        .len = 6,
                },
        },
};

static void st_lsm6dsx_shub_wait_complete(struct st_lsm6dsx_hw *hw)
{
        struct st_lsm6dsx_sensor *sensor;
        u32 odr, timeout;

        sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_ACC]);
        odr = (hw->enable_mask & BIT(ST_LSM6DSX_ID_ACC)) ? sensor->odr : 12500;
        /* set 10ms as minimum timeout for i2c slave configuration */
        timeout = max_t(u32, 2000000U / odr + 1, 10);
        msleep(timeout);
}

/*
 * st_lsm6dsx_shub_read_output - read i2c controller register
 *
 * Read st_lsm6dsx i2c controller register
 */
int st_lsm6dsx_shub_read_output(struct st_lsm6dsx_hw *hw, u8 *data, int len)
{
        const struct st_lsm6dsx_shub_settings *hub_settings;
        int err;

        mutex_lock(&hw->page_lock);

        hub_settings = &hw->settings->shub_settings;
        if (hub_settings->shub_out.sec_page) {
                err = st_lsm6dsx_set_page(hw, true);
                if (err < 0)
                        goto out;
        }

        err = regmap_bulk_read(hw->regmap, hub_settings->shub_out.addr,
                               data, len);

        if (hub_settings->shub_out.sec_page)
                st_lsm6dsx_set_page(hw, false);
out:
        mutex_unlock(&hw->page_lock);

        return err;
}

/*
 * st_lsm6dsx_shub_write_reg - write i2c controller register
 *
 * Write st_lsm6dsx i2c controller register
 */
static int st_lsm6dsx_shub_write_reg(struct st_lsm6dsx_hw *hw, u8 addr,
                                     u8 *data, int len)
{
        int err;

        mutex_lock(&hw->page_lock);
        err = st_lsm6dsx_set_page(hw, true);
        if (err < 0)
                goto out;

        err = regmap_bulk_write(hw->regmap, addr, data, len);

        st_lsm6dsx_set_page(hw, false);
out:
        mutex_unlock(&hw->page_lock);

        return err;
}

static int
st_lsm6dsx_shub_write_reg_with_mask(struct st_lsm6dsx_hw *hw, u8 addr,
                                    u8 mask, u8 val)
{
        int err;

        mutex_lock(&hw->page_lock);
        err = st_lsm6dsx_set_page(hw, true);
        if (err < 0)
                goto out;

        err = regmap_update_bits(hw->regmap, addr, mask, val);

        st_lsm6dsx_set_page(hw, false);
out:
        mutex_unlock(&hw->page_lock);

        return err;
}

static int st_lsm6dsx_shub_master_enable(struct st_lsm6dsx_sensor *sensor,
                                         bool enable)
{
        const struct st_lsm6dsx_shub_settings *hub_settings;
        struct st_lsm6dsx_hw *hw = sensor->hw;
        unsigned int data;
        int err;

        /* enable acc sensor as trigger */
        err = st_lsm6dsx_sensor_set_enable(sensor, enable);
        if (err < 0)
                return err;

        mutex_lock(&hw->page_lock);

        hub_settings = &hw->settings->shub_settings;
        if (hub_settings->master_en.sec_page) {
                err = st_lsm6dsx_set_page(hw, true);
                if (err < 0)
                        goto out;
        }

        data = ST_LSM6DSX_SHIFT_VAL(enable, hub_settings->master_en.mask);
        err = regmap_update_bits(hw->regmap, hub_settings->master_en.addr,
                                 hub_settings->master_en.mask, data);

        if (hub_settings->master_en.sec_page)
                st_lsm6dsx_set_page(hw, false);
out:
        mutex_unlock(&hw->page_lock);

        return err;
}

/*
 * st_lsm6dsx_shub_read - read data from slave device register
 *
 * Read data from slave device register. SLV0 is used for
 * one-shot read operation
 */
static int
st_lsm6dsx_shub_read(struct st_lsm6dsx_sensor *sensor, u8 addr,
                     u8 *data, int len)
{
        const struct st_lsm6dsx_shub_settings *hub_settings;
        u8 config[3], slv_addr, slv_config = 0;
        struct st_lsm6dsx_hw *hw = sensor->hw;
        const struct st_lsm6dsx_reg *aux_sens;
        int err;

        hub_settings = &hw->settings->shub_settings;
        slv_addr = ST_LSM6DSX_SLV_ADDR(0, hub_settings->slv0_addr);
        aux_sens = &hw->settings->shub_settings.aux_sens;
        /* do not overwrite aux_sens */
        if (slv_addr + 2 == aux_sens->addr)
                slv_config = ST_LSM6DSX_SHIFT_VAL(3, aux_sens->mask);

        config[0] = (sensor->ext_info.addr << 1) | 1;
        config[1] = addr;
        config[2] = (len & ST_LS6DSX_READ_OP_MASK) | slv_config;

        err = st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
                                        sizeof(config));
        if (err < 0)
                return err;

        err = st_lsm6dsx_shub_master_enable(sensor, true);
        if (err < 0)
                return err;

        st_lsm6dsx_shub_wait_complete(hw);

        err = st_lsm6dsx_shub_read_output(hw, data,
                                          len & ST_LS6DSX_READ_OP_MASK);
        if (err < 0)
                return err;

        st_lsm6dsx_shub_master_enable(sensor, false);

        config[0] = hub_settings->pause;
        config[1] = 0;
        config[2] = slv_config;
        return st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
                                         sizeof(config));
}

/*
 * st_lsm6dsx_shub_write - write data to slave device register
 *
 * Write data from slave device register. SLV0 is used for
 * one-shot write operation
 */
static int
st_lsm6dsx_shub_write(struct st_lsm6dsx_sensor *sensor, u8 addr,
                      u8 *data, int len)
{
        const struct st_lsm6dsx_shub_settings *hub_settings;
        struct st_lsm6dsx_hw *hw = sensor->hw;
        u8 config[2], slv_addr;
        int err, i;

        hub_settings = &hw->settings->shub_settings;
        if (hub_settings->wr_once.addr) {
                unsigned int data;

                data = ST_LSM6DSX_SHIFT_VAL(1, hub_settings->wr_once.mask);
                err = st_lsm6dsx_shub_write_reg_with_mask(hw,
                        hub_settings->wr_once.addr,
                        hub_settings->wr_once.mask,
                        data);
                if (err < 0)
                        return err;
        }

        slv_addr = ST_LSM6DSX_SLV_ADDR(0, hub_settings->slv0_addr);
        config[0] = sensor->ext_info.addr << 1;
        for (i = 0 ; i < len; i++) {
                config[1] = addr + i;

                err = st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
                                                sizeof(config));
                if (err < 0)
                        return err;

                err = st_lsm6dsx_shub_write_reg(hw, hub_settings->dw_slv0_addr,
                                                &data[i], 1);
                if (err < 0)
                        return err;

                err = st_lsm6dsx_shub_master_enable(sensor, true);
                if (err < 0)
                        return err;

                st_lsm6dsx_shub_wait_complete(hw);

                st_lsm6dsx_shub_master_enable(sensor, false);
        }

        config[0] = hub_settings->pause;
        config[1] = 0;
        return st_lsm6dsx_shub_write_reg(hw, slv_addr, config, sizeof(config));
}

static int
st_lsm6dsx_shub_write_with_mask(struct st_lsm6dsx_sensor *sensor,
                                u8 addr, u8 mask, u8 val)
{
        int err;
        u8 data;

        err = st_lsm6dsx_shub_read(sensor, addr, &data, sizeof(data));
        if (err < 0)
                return err;

        data = ((data & ~mask) | (val << __ffs(mask) & mask));

        return st_lsm6dsx_shub_write(sensor, addr, &data, sizeof(data));
}

static int
st_lsm6dsx_shub_get_odr_val(struct st_lsm6dsx_sensor *sensor,
                            u32 odr, u16 *val)
{
        const struct st_lsm6dsx_ext_dev_settings *settings;
        int i;

        settings = sensor->ext_info.settings;
        for (i = 0; i < settings->odr_table.odr_len; i++) {
                if (settings->odr_table.odr_avl[i].milli_hz == odr)
                        break;
        }

        if (i == settings->odr_table.odr_len)
                return -EINVAL;

        *val = settings->odr_table.odr_avl[i].val;
        return 0;
}

static int
st_lsm6dsx_shub_set_odr(struct st_lsm6dsx_sensor *sensor, u32 odr)
{
        const struct st_lsm6dsx_ext_dev_settings *settings;
        u16 val;
        int err;

        err = st_lsm6dsx_shub_get_odr_val(sensor, odr, &val);
        if (err < 0)
                return err;

        settings = sensor->ext_info.settings;
        return st_lsm6dsx_shub_write_with_mask(sensor,
                                               settings->odr_table.reg.addr,
                                               settings->odr_table.reg.mask,
                                               val);
}

/* use SLV{1,2,3} for FIFO read operations */
static int
st_lsm6dsx_shub_config_channels(struct st_lsm6dsx_sensor *sensor,
                                bool enable)
{
        const struct st_lsm6dsx_shub_settings *hub_settings;
        const struct st_lsm6dsx_ext_dev_settings *settings;
        u8 config[9] = {}, enable_mask, slv_addr;
        struct st_lsm6dsx_hw *hw = sensor->hw;
        struct st_lsm6dsx_sensor *cur_sensor;
        int i, j = 0;

        hub_settings = &hw->settings->shub_settings;
        if (enable)
                enable_mask = hw->enable_mask | BIT(sensor->id);
        else
                enable_mask = hw->enable_mask & ~BIT(sensor->id);

        for (i = ST_LSM6DSX_ID_EXT0; i <= ST_LSM6DSX_ID_EXT2; i++) {
                if (!hw->iio_devs[i])
                        continue;

                cur_sensor = iio_priv(hw->iio_devs[i]);
                if (!(enable_mask & BIT(cur_sensor->id)))
                        continue;

                settings = cur_sensor->ext_info.settings;
                config[j] = (sensor->ext_info.addr << 1) | 1;
                config[j + 1] = settings->out.addr;
                config[j + 2] = (settings->out.len & ST_LS6DSX_READ_OP_MASK) |
                                hub_settings->batch_en;
                j += 3;
        }

        slv_addr = ST_LSM6DSX_SLV_ADDR(1, hub_settings->slv0_addr);
        return st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
                                         sizeof(config));
}

int st_lsm6dsx_shub_set_enable(struct st_lsm6dsx_sensor *sensor, bool enable)
{
        const struct st_lsm6dsx_ext_dev_settings *settings;
        int err;

        err = st_lsm6dsx_shub_config_channels(sensor, enable);
        if (err < 0)
                return err;

        settings = sensor->ext_info.settings;
        if (enable) {
                err = st_lsm6dsx_shub_set_odr(sensor,
                                              sensor->ext_info.slv_odr);
                if (err < 0)
                        return err;
        } else {
                err = st_lsm6dsx_shub_write_with_mask(sensor,
                                        settings->odr_table.reg.addr,
                                        settings->odr_table.reg.mask, 0);
                if (err < 0)
                        return err;
        }

        if (settings->pwr_table.reg.addr) {
                u8 val;

                val = enable ? settings->pwr_table.on_val
                             : settings->pwr_table.off_val;
                err = st_lsm6dsx_shub_write_with_mask(sensor,
                                        settings->pwr_table.reg.addr,
                                        settings->pwr_table.reg.mask, val);
                if (err < 0)
                        return err;
        }

        return st_lsm6dsx_shub_master_enable(sensor, enable);
}

static int
st_lsm6dsx_shub_read_oneshot(struct st_lsm6dsx_sensor *sensor,
                             struct iio_chan_spec const *ch,
                             int *val)
{
        int err, delay, len;
        u8 data[4];

        err = st_lsm6dsx_shub_set_enable(sensor, true);
        if (err < 0)
                return err;

        delay = 1000000000 / sensor->ext_info.slv_odr;
        usleep_range(delay, 2 * delay);

        len = min_t(int, sizeof(data), ch->scan_type.realbits >> 3);
        err = st_lsm6dsx_shub_read(sensor, ch->address, data, len);
        if (err < 0)
                return err;

        err = st_lsm6dsx_shub_set_enable(sensor, false);
        if (err < 0)
                return err;

        switch (len) {
        case 2:
                *val = (s16)le16_to_cpu(*((__le16 *)data));
                break;
        default:
                return -EINVAL;
        }

        return IIO_VAL_INT;
}

static int
st_lsm6dsx_shub_read_raw(struct iio_dev *iio_dev,
                         struct iio_chan_spec const *ch,
                         int *val, int *val2, long mask)
{
        struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
        int ret;

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

                ret = st_lsm6dsx_shub_read_oneshot(sensor, ch, val);
                iio_device_release_direct(iio_dev);
                break;
        case IIO_CHAN_INFO_SAMP_FREQ:
                *val = sensor->ext_info.slv_odr / 1000;
                *val2 = (sensor->ext_info.slv_odr % 1000) * 1000;
                ret = IIO_VAL_INT_PLUS_MICRO;
                break;
        case IIO_CHAN_INFO_SCALE:
                *val = 0;
                *val2 = sensor->gain;
                ret = IIO_VAL_INT_PLUS_MICRO;
                break;
        default:
                ret = -EINVAL;
                break;
        }

        return ret;
}

static int
st_lsm6dsx_shub_set_full_scale(struct st_lsm6dsx_sensor *sensor,
                               u32 gain)
{
        const struct st_lsm6dsx_fs_table_entry *fs_table;
        int i, err;

        fs_table = &sensor->ext_info.settings->fs_table;
        if (!fs_table->reg.addr)
                return -ENOTSUPP;

        for (i = 0; i < fs_table->fs_len; i++) {
                if (fs_table->fs_avl[i].gain == gain)
                        break;
        }

        if (i == fs_table->fs_len)
                return -EINVAL;

        err = st_lsm6dsx_shub_write_with_mask(sensor, fs_table->reg.addr,
                                              fs_table->reg.mask,
                                              fs_table->fs_avl[i].val);
        if (err < 0)
                return err;

        sensor->gain = gain;

        return 0;
}

static int
__st_lsm6dsx_shub_write_raw(struct iio_dev *iio_dev,
                            struct iio_chan_spec const *chan,
                            int val, int val2, long mask)
{
        struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
        int err;

        switch (mask) {
        case IIO_CHAN_INFO_SAMP_FREQ: {
                struct st_lsm6dsx_hw *hw = sensor->hw;
                struct st_lsm6dsx_sensor *ref_sensor;
                u8 odr_val;
                u16 data;
                int odr;

                val = val * 1000 + val2 / 1000;
                err = st_lsm6dsx_shub_get_odr_val(sensor, val, &data);
                if (err)
                        return err;

                ref_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_ACC]);
                odr = st_lsm6dsx_check_odr(ref_sensor, val, &odr_val);
                if (odr < 0)
                        return odr;

                sensor->ext_info.slv_odr = val;
                sensor->odr = odr;
                sensor->hwfifo_odr_mHz = odr;
                return 0;
        }
        case IIO_CHAN_INFO_SCALE:
                return st_lsm6dsx_shub_set_full_scale(sensor, val2);
        default:
                return -EINVAL;
        }
}

static int
st_lsm6dsx_shub_write_raw(struct iio_dev *iio_dev,
                          struct iio_chan_spec const *chan,
                          int val, int val2, long mask)
{
        int ret;

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

        ret = __st_lsm6dsx_shub_write_raw(iio_dev, chan, val, val2, mask);

        iio_device_release_direct(iio_dev);

        return ret;
}

static ssize_t
st_lsm6dsx_shub_sampling_freq_avail(struct device *dev,
                                    struct device_attribute *attr,
                                    char *buf)
{
        struct st_lsm6dsx_sensor *sensor = iio_priv(dev_get_drvdata(dev));
        const struct st_lsm6dsx_ext_dev_settings *settings;
        int i, len = 0;

        settings = sensor->ext_info.settings;
        for (i = 0; i < settings->odr_table.odr_len; i++) {
                u32 val = settings->odr_table.odr_avl[i].milli_hz;

                len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%03d ",
                                 val / 1000, val % 1000);
        }
        buf[len - 1] = '\n';

        return len;
}

static ssize_t st_lsm6dsx_shub_scale_avail(struct device *dev,
                                           struct device_attribute *attr,
                                           char *buf)
{
        struct st_lsm6dsx_sensor *sensor = iio_priv(dev_get_drvdata(dev));
        const struct st_lsm6dsx_ext_dev_settings *settings;
        int i, len = 0;

        settings = sensor->ext_info.settings;
        for (i = 0; i < settings->fs_table.fs_len; i++)
                len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06u ",
                                 settings->fs_table.fs_avl[i].gain);
        buf[len - 1] = '\n';

        return len;
}

static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(st_lsm6dsx_shub_sampling_freq_avail);
static IIO_DEVICE_ATTR(in_scale_available, 0444,
                       st_lsm6dsx_shub_scale_avail, NULL, 0);
static struct attribute *st_lsm6dsx_shub_attributes[] = {
        &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
        &iio_dev_attr_in_scale_available.dev_attr.attr,
        NULL,
};

static const struct attribute_group st_lsm6dsx_shub_attribute_group = {
        .attrs = st_lsm6dsx_shub_attributes,
};

static const struct iio_info st_lsm6dsx_shub_info = {
        .attrs = &st_lsm6dsx_shub_attribute_group,
        .read_raw = st_lsm6dsx_shub_read_raw,
        .write_raw = st_lsm6dsx_shub_write_raw,
        .hwfifo_set_watermark = st_lsm6dsx_set_watermark,
};

static struct iio_dev *
st_lsm6dsx_shub_alloc_iiodev(struct st_lsm6dsx_hw *hw,
                             enum st_lsm6dsx_sensor_id id,
                             const struct st_lsm6dsx_ext_dev_settings *info,
                             u8 i2c_addr, const char *name)
{
        enum st_lsm6dsx_sensor_id ref_id = ST_LSM6DSX_ID_ACC;
        struct iio_chan_spec *ext_channels;
        struct st_lsm6dsx_sensor *sensor;
        struct iio_dev *iio_dev;

        iio_dev = devm_iio_device_alloc(hw->dev, sizeof(*sensor));
        if (!iio_dev)
                return NULL;

        iio_dev->modes = INDIO_DIRECT_MODE;
        iio_dev->info = &st_lsm6dsx_shub_info;

        sensor = iio_priv(iio_dev);
        sensor->id = id;
        sensor->hw = hw;
        sensor->odr = hw->settings->odr_table[ref_id].odr_avl[0].milli_hz;
        sensor->hwfifo_odr_mHz = sensor->odr;
        sensor->ext_info.slv_odr = info->odr_table.odr_avl[0].milli_hz;
        sensor->gain = info->fs_table.fs_avl[0].gain;
        sensor->ext_info.settings = info;
        sensor->ext_info.addr = i2c_addr;
        sensor->watermark = 1;

        switch (info->id) {
        case ST_LSM6DSX_ID_MAGN: {
                const struct iio_chan_spec magn_channels[] = {
                        ST_LSM6DSX_CHANNEL(IIO_MAGN, info->out.addr,
                                           IIO_MOD_X, 0),
                        ST_LSM6DSX_CHANNEL(IIO_MAGN, info->out.addr + 2,
                                           IIO_MOD_Y, 1),
                        ST_LSM6DSX_CHANNEL(IIO_MAGN, info->out.addr + 4,
                                           IIO_MOD_Z, 2),
                        IIO_CHAN_SOFT_TIMESTAMP(3),
                };

                ext_channels = devm_kzalloc(hw->dev, sizeof(magn_channels),
                                            GFP_KERNEL);
                if (!ext_channels)
                        return NULL;

                memcpy(ext_channels, magn_channels, sizeof(magn_channels));
                iio_dev->available_scan_masks = st_lsm6dsx_available_scan_masks;
                iio_dev->channels = ext_channels;
                iio_dev->num_channels = ARRAY_SIZE(magn_channels);

                scnprintf(sensor->name, sizeof(sensor->name), "%s_magn",
                          name);
                break;
        }
        default:
                return NULL;
        }
        iio_dev->name = sensor->name;

        return iio_dev;
}

static int st_lsm6dsx_shub_init_device(struct st_lsm6dsx_sensor *sensor)
{
        const struct st_lsm6dsx_ext_dev_settings *settings;
        int err;

        settings = sensor->ext_info.settings;
        if (settings->bdu.addr) {
                err = st_lsm6dsx_shub_write_with_mask(sensor,
                                                      settings->bdu.addr,
                                                      settings->bdu.mask, 1);
                if (err < 0)
                        return err;
        }

        if (settings->temp_comp.addr) {
                err = st_lsm6dsx_shub_write_with_mask(sensor,
                                        settings->temp_comp.addr,
                                        settings->temp_comp.mask, 1);
                if (err < 0)
                        return err;
        }

        if (settings->off_canc.addr) {
                err = st_lsm6dsx_shub_write_with_mask(sensor,
                                        settings->off_canc.addr,
                                        settings->off_canc.mask, 1);
                if (err < 0)
                        return err;
        }

        return 0;
}

static int
st_lsm6dsx_shub_check_wai(struct st_lsm6dsx_hw *hw, u8 *i2c_addr,
                          const struct st_lsm6dsx_ext_dev_settings *settings)
{
        const struct st_lsm6dsx_shub_settings *hub_settings;
        u8 config[3], data, slv_addr, slv_config = 0;
        const struct st_lsm6dsx_reg *aux_sens;
        struct st_lsm6dsx_sensor *sensor;
        bool found = false;
        int i, err;

        sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_ACC]);
        hub_settings = &hw->settings->shub_settings;
        aux_sens = &hw->settings->shub_settings.aux_sens;
        slv_addr = ST_LSM6DSX_SLV_ADDR(0, hub_settings->slv0_addr);
        /* do not overwrite aux_sens */
        if (slv_addr + 2 == aux_sens->addr)
                slv_config = ST_LSM6DSX_SHIFT_VAL(3, aux_sens->mask);

        for (i = 0; i < ARRAY_SIZE(settings->i2c_addr); i++) {
                if (!settings->i2c_addr[i])
                        continue;

                /* read wai slave register */
                config[0] = (settings->i2c_addr[i] << 1) | 0x1;
                config[1] = settings->wai.addr;
                config[2] = 0x1 | slv_config;

                err = st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
                                                sizeof(config));
                if (err < 0)
                        return err;

                err = st_lsm6dsx_shub_master_enable(sensor, true);
                if (err < 0)
                        return err;

                st_lsm6dsx_shub_wait_complete(hw);

                err = st_lsm6dsx_shub_read_output(hw, &data, sizeof(data));

                st_lsm6dsx_shub_master_enable(sensor, false);

                if (err < 0)
                        return err;

                if (data != settings->wai.val)
                        continue;

                *i2c_addr = settings->i2c_addr[i];
                found = true;
                break;
        }

        /* reset SLV0 channel */
        config[0] = hub_settings->pause;
        config[1] = 0;
        config[2] = slv_config;
        err = st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
                                        sizeof(config));
        if (err < 0)
                return err;

        return found ? 0 : -ENODEV;
}

int st_lsm6dsx_shub_probe(struct st_lsm6dsx_hw *hw, const char *name)
{
        enum st_lsm6dsx_sensor_id id = ST_LSM6DSX_ID_EXT0;
        struct st_lsm6dsx_sensor *sensor;
        int err, i, num_ext_dev = 0;
        u8 i2c_addr = 0;

        for (i = 0; i < ARRAY_SIZE(st_lsm6dsx_ext_dev_table); i++) {
                err = st_lsm6dsx_shub_check_wai(hw, &i2c_addr,
                                        &st_lsm6dsx_ext_dev_table[i]);
                if (err == -ENODEV)
                        continue;
                else if (err < 0)
                        return err;

                hw->iio_devs[id] = st_lsm6dsx_shub_alloc_iiodev(hw, id,
                                                &st_lsm6dsx_ext_dev_table[i],
                                                i2c_addr, name);
                if (!hw->iio_devs[id])
                        return -ENOMEM;

                sensor = iio_priv(hw->iio_devs[id]);
                err = st_lsm6dsx_shub_init_device(sensor);
                if (err < 0)
                        return err;

                if (++num_ext_dev >= hw->settings->shub_settings.num_ext_dev)
                        break;
                id++;
        }

        return 0;
}