powerpc/mm: Ensure cpumask update is ordered

[mirror_ubuntu-artful-kernel.git] / drivers / iio / accel / bmc150-accel-core.c

/*
 * 3-axis accelerometer driver supporting following Bosch-Sensortec chips:
 *  - BMC150
 *  - BMI055
 *  - BMA255
 *  - BMA250E
 *  - BMA222E
 *  - BMA280
 *
 * Copyright (c) 2014, Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/events.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/regmap.h>

#include "bmc150-accel.h"

#define BMC150_ACCEL_DRV_NAME                   "bmc150_accel"
#define BMC150_ACCEL_IRQ_NAME                   "bmc150_accel_event"

#define BMC150_ACCEL_REG_CHIP_ID                0x00

#define BMC150_ACCEL_REG_INT_STATUS_2           0x0B
#define BMC150_ACCEL_ANY_MOTION_MASK            0x07
#define BMC150_ACCEL_ANY_MOTION_BIT_X           BIT(0)
#define BMC150_ACCEL_ANY_MOTION_BIT_Y           BIT(1)
#define BMC150_ACCEL_ANY_MOTION_BIT_Z           BIT(2)
#define BMC150_ACCEL_ANY_MOTION_BIT_SIGN        BIT(3)

#define BMC150_ACCEL_REG_PMU_LPW                0x11
#define BMC150_ACCEL_PMU_MODE_MASK              0xE0
#define BMC150_ACCEL_PMU_MODE_SHIFT             5
#define BMC150_ACCEL_PMU_BIT_SLEEP_DUR_MASK     0x17
#define BMC150_ACCEL_PMU_BIT_SLEEP_DUR_SHIFT    1

#define BMC150_ACCEL_REG_PMU_RANGE              0x0F

#define BMC150_ACCEL_DEF_RANGE_2G               0x03
#define BMC150_ACCEL_DEF_RANGE_4G               0x05
#define BMC150_ACCEL_DEF_RANGE_8G               0x08
#define BMC150_ACCEL_DEF_RANGE_16G              0x0C

/* Default BW: 125Hz */
#define BMC150_ACCEL_REG_PMU_BW         0x10
#define BMC150_ACCEL_DEF_BW                     125

#define BMC150_ACCEL_REG_RESET                  0x14
#define BMC150_ACCEL_RESET_VAL                  0xB6

#define BMC150_ACCEL_REG_INT_MAP_0              0x19
#define BMC150_ACCEL_INT_MAP_0_BIT_SLOPE        BIT(2)

#define BMC150_ACCEL_REG_INT_MAP_1              0x1A
#define BMC150_ACCEL_INT_MAP_1_BIT_DATA         BIT(0)
#define BMC150_ACCEL_INT_MAP_1_BIT_FWM          BIT(1)
#define BMC150_ACCEL_INT_MAP_1_BIT_FFULL        BIT(2)

#define BMC150_ACCEL_REG_INT_RST_LATCH          0x21
#define BMC150_ACCEL_INT_MODE_LATCH_RESET       0x80
#define BMC150_ACCEL_INT_MODE_LATCH_INT 0x0F
#define BMC150_ACCEL_INT_MODE_NON_LATCH_INT     0x00

#define BMC150_ACCEL_REG_INT_EN_0               0x16
#define BMC150_ACCEL_INT_EN_BIT_SLP_X           BIT(0)
#define BMC150_ACCEL_INT_EN_BIT_SLP_Y           BIT(1)
#define BMC150_ACCEL_INT_EN_BIT_SLP_Z           BIT(2)

#define BMC150_ACCEL_REG_INT_EN_1               0x17
#define BMC150_ACCEL_INT_EN_BIT_DATA_EN         BIT(4)
#define BMC150_ACCEL_INT_EN_BIT_FFULL_EN        BIT(5)
#define BMC150_ACCEL_INT_EN_BIT_FWM_EN          BIT(6)

#define BMC150_ACCEL_REG_INT_OUT_CTRL           0x20
#define BMC150_ACCEL_INT_OUT_CTRL_INT1_LVL      BIT(0)

#define BMC150_ACCEL_REG_INT_5                  0x27
#define BMC150_ACCEL_SLOPE_DUR_MASK             0x03

#define BMC150_ACCEL_REG_INT_6                  0x28
#define BMC150_ACCEL_SLOPE_THRES_MASK           0xFF

/* Slope duration in terms of number of samples */
#define BMC150_ACCEL_DEF_SLOPE_DURATION         1
/* in terms of multiples of g's/LSB, based on range */
#define BMC150_ACCEL_DEF_SLOPE_THRESHOLD        1

#define BMC150_ACCEL_REG_XOUT_L         0x02

#define BMC150_ACCEL_MAX_STARTUP_TIME_MS        100

/* Sleep Duration values */
#define BMC150_ACCEL_SLEEP_500_MICRO            0x05
#define BMC150_ACCEL_SLEEP_1_MS         0x06
#define BMC150_ACCEL_SLEEP_2_MS         0x07
#define BMC150_ACCEL_SLEEP_4_MS         0x08
#define BMC150_ACCEL_SLEEP_6_MS         0x09
#define BMC150_ACCEL_SLEEP_10_MS                0x0A
#define BMC150_ACCEL_SLEEP_25_MS                0x0B
#define BMC150_ACCEL_SLEEP_50_MS                0x0C
#define BMC150_ACCEL_SLEEP_100_MS               0x0D
#define BMC150_ACCEL_SLEEP_500_MS               0x0E
#define BMC150_ACCEL_SLEEP_1_SEC                0x0F

#define BMC150_ACCEL_REG_TEMP                   0x08
#define BMC150_ACCEL_TEMP_CENTER_VAL            24

#define BMC150_ACCEL_AXIS_TO_REG(axis)  (BMC150_ACCEL_REG_XOUT_L + (axis * 2))
#define BMC150_AUTO_SUSPEND_DELAY_MS            2000

#define BMC150_ACCEL_REG_FIFO_STATUS            0x0E
#define BMC150_ACCEL_REG_FIFO_CONFIG0           0x30
#define BMC150_ACCEL_REG_FIFO_CONFIG1           0x3E
#define BMC150_ACCEL_REG_FIFO_DATA              0x3F
#define BMC150_ACCEL_FIFO_LENGTH                32

enum bmc150_accel_axis {
        AXIS_X,
        AXIS_Y,
        AXIS_Z,
        AXIS_MAX,
};

enum bmc150_power_modes {
        BMC150_ACCEL_SLEEP_MODE_NORMAL,
        BMC150_ACCEL_SLEEP_MODE_DEEP_SUSPEND,
        BMC150_ACCEL_SLEEP_MODE_LPM,
        BMC150_ACCEL_SLEEP_MODE_SUSPEND = 0x04,
};

struct bmc150_scale_info {
        int scale;
        u8 reg_range;
};

struct bmc150_accel_chip_info {
        const char *name;
        u8 chip_id;
        const struct iio_chan_spec *channels;
        int num_channels;
        const struct bmc150_scale_info scale_table[4];
};

struct bmc150_accel_interrupt {
        const struct bmc150_accel_interrupt_info *info;
        atomic_t users;
};

struct bmc150_accel_trigger {
        struct bmc150_accel_data *data;
        struct iio_trigger *indio_trig;
        int (*setup)(struct bmc150_accel_trigger *t, bool state);
        int intr;
        bool enabled;
};

enum bmc150_accel_interrupt_id {
        BMC150_ACCEL_INT_DATA_READY,
        BMC150_ACCEL_INT_ANY_MOTION,
        BMC150_ACCEL_INT_WATERMARK,
        BMC150_ACCEL_INTERRUPTS,
};

enum bmc150_accel_trigger_id {
        BMC150_ACCEL_TRIGGER_DATA_READY,
        BMC150_ACCEL_TRIGGER_ANY_MOTION,
        BMC150_ACCEL_TRIGGERS,
};

struct bmc150_accel_data {
        struct regmap *regmap;
        int irq;
        struct bmc150_accel_interrupt interrupts[BMC150_ACCEL_INTERRUPTS];
        atomic_t active_intr;
        struct bmc150_accel_trigger triggers[BMC150_ACCEL_TRIGGERS];
        struct mutex mutex;
        u8 fifo_mode, watermark;
        s16 buffer[8];
        u8 bw_bits;
        u32 slope_dur;
        u32 slope_thres;
        u32 range;
        int ev_enable_state;
        int64_t timestamp, old_timestamp; /* Only used in hw fifo mode. */
        const struct bmc150_accel_chip_info *chip_info;
};

static const struct {
        int val;
        int val2;
        u8 bw_bits;
} bmc150_accel_samp_freq_table[] = { {15, 620000, 0x08},
                                     {31, 260000, 0x09},
                                     {62, 500000, 0x0A},
                                     {125, 0, 0x0B},
                                     {250, 0, 0x0C},
                                     {500, 0, 0x0D},
                                     {1000, 0, 0x0E},
                                     {2000, 0, 0x0F} };

static const struct {
        int bw_bits;
        int msec;
} bmc150_accel_sample_upd_time[] = { {0x08, 64},
                                     {0x09, 32},
                                     {0x0A, 16},
                                     {0x0B, 8},
                                     {0x0C, 4},
                                     {0x0D, 2},
                                     {0x0E, 1},
                                     {0x0F, 1} };

static const struct {
        int sleep_dur;
        u8 reg_value;
} bmc150_accel_sleep_value_table[] = { {0, 0},
                                       {500, BMC150_ACCEL_SLEEP_500_MICRO},
                                       {1000, BMC150_ACCEL_SLEEP_1_MS},
                                       {2000, BMC150_ACCEL_SLEEP_2_MS},
                                       {4000, BMC150_ACCEL_SLEEP_4_MS},
                                       {6000, BMC150_ACCEL_SLEEP_6_MS},
                                       {10000, BMC150_ACCEL_SLEEP_10_MS},
                                       {25000, BMC150_ACCEL_SLEEP_25_MS},
                                       {50000, BMC150_ACCEL_SLEEP_50_MS},
                                       {100000, BMC150_ACCEL_SLEEP_100_MS},
                                       {500000, BMC150_ACCEL_SLEEP_500_MS},
                                       {1000000, BMC150_ACCEL_SLEEP_1_SEC} };

const struct regmap_config bmc150_regmap_conf = {
        .reg_bits = 8,
        .val_bits = 8,
        .max_register = 0x3f,
};
EXPORT_SYMBOL_GPL(bmc150_regmap_conf);

static int bmc150_accel_set_mode(struct bmc150_accel_data *data,
                                 enum bmc150_power_modes mode,
                                 int dur_us)
{
        struct device *dev = regmap_get_device(data->regmap);
        int i;
        int ret;
        u8 lpw_bits;
        int dur_val = -1;

        if (dur_us > 0) {
                for (i = 0; i < ARRAY_SIZE(bmc150_accel_sleep_value_table);
                                                                         ++i) {
                        if (bmc150_accel_sleep_value_table[i].sleep_dur ==
                                                                        dur_us)
                                dur_val =
                                bmc150_accel_sleep_value_table[i].reg_value;
                }
        } else {
                dur_val = 0;
        }

        if (dur_val < 0)
                return -EINVAL;

        lpw_bits = mode << BMC150_ACCEL_PMU_MODE_SHIFT;
        lpw_bits |= (dur_val << BMC150_ACCEL_PMU_BIT_SLEEP_DUR_SHIFT);

        dev_dbg(dev, "Set Mode bits %x\n", lpw_bits);

        ret = regmap_write(data->regmap, BMC150_ACCEL_REG_PMU_LPW, lpw_bits);
        if (ret < 0) {
                dev_err(dev, "Error writing reg_pmu_lpw\n");
                return ret;
        }

        return 0;
}

static int bmc150_accel_set_bw(struct bmc150_accel_data *data, int val,
                               int val2)
{
        int i;
        int ret;

        for (i = 0; i < ARRAY_SIZE(bmc150_accel_samp_freq_table); ++i) {
                if (bmc150_accel_samp_freq_table[i].val == val &&
                    bmc150_accel_samp_freq_table[i].val2 == val2) {
                        ret = regmap_write(data->regmap,
                                BMC150_ACCEL_REG_PMU_BW,
                                bmc150_accel_samp_freq_table[i].bw_bits);
                        if (ret < 0)
                                return ret;

                        data->bw_bits =
                                bmc150_accel_samp_freq_table[i].bw_bits;
                        return 0;
                }
        }

        return -EINVAL;
}

static int bmc150_accel_update_slope(struct bmc150_accel_data *data)
{
        struct device *dev = regmap_get_device(data->regmap);
        int ret;

        ret = regmap_write(data->regmap, BMC150_ACCEL_REG_INT_6,
                                        data->slope_thres);
        if (ret < 0) {
                dev_err(dev, "Error writing reg_int_6\n");
                return ret;
        }

        ret = regmap_update_bits(data->regmap, BMC150_ACCEL_REG_INT_5,
                                 BMC150_ACCEL_SLOPE_DUR_MASK, data->slope_dur);
        if (ret < 0) {
                dev_err(dev, "Error updating reg_int_5\n");
                return ret;
        }

        dev_dbg(dev, "%s: %x %x\n", __func__, data->slope_thres,
                data->slope_dur);

        return ret;
}

static int bmc150_accel_any_motion_setup(struct bmc150_accel_trigger *t,
                                         bool state)
{
        if (state)
                return bmc150_accel_update_slope(t->data);

        return 0;
}

static int bmc150_accel_get_bw(struct bmc150_accel_data *data, int *val,
                               int *val2)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(bmc150_accel_samp_freq_table); ++i) {
                if (bmc150_accel_samp_freq_table[i].bw_bits == data->bw_bits) {
                        *val = bmc150_accel_samp_freq_table[i].val;
                        *val2 = bmc150_accel_samp_freq_table[i].val2;
                        return IIO_VAL_INT_PLUS_MICRO;
                }
        }

        return -EINVAL;
}

#ifdef CONFIG_PM
static int bmc150_accel_get_startup_times(struct bmc150_accel_data *data)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(bmc150_accel_sample_upd_time); ++i) {
                if (bmc150_accel_sample_upd_time[i].bw_bits == data->bw_bits)
                        return bmc150_accel_sample_upd_time[i].msec;
        }

        return BMC150_ACCEL_MAX_STARTUP_TIME_MS;
}

static int bmc150_accel_set_power_state(struct bmc150_accel_data *data, bool on)
{
        struct device *dev = regmap_get_device(data->regmap);
        int ret;

        if (on) {
                ret = pm_runtime_get_sync(dev);
        } else {
                pm_runtime_mark_last_busy(dev);
                ret = pm_runtime_put_autosuspend(dev);
        }

        if (ret < 0) {
                dev_err(dev,
                        "Failed: bmc150_accel_set_power_state for %d\n", on);
                if (on)
                        pm_runtime_put_noidle(dev);

                return ret;
        }

        return 0;
}
#else
static int bmc150_accel_set_power_state(struct bmc150_accel_data *data, bool on)
{
        return 0;
}
#endif

static const struct bmc150_accel_interrupt_info {
        u8 map_reg;
        u8 map_bitmask;
        u8 en_reg;
        u8 en_bitmask;
} bmc150_accel_interrupts[BMC150_ACCEL_INTERRUPTS] = {
        { /* data ready interrupt */
                .map_reg = BMC150_ACCEL_REG_INT_MAP_1,
                .map_bitmask = BMC150_ACCEL_INT_MAP_1_BIT_DATA,
                .en_reg = BMC150_ACCEL_REG_INT_EN_1,
                .en_bitmask = BMC150_ACCEL_INT_EN_BIT_DATA_EN,
        },
        {  /* motion interrupt */
                .map_reg = BMC150_ACCEL_REG_INT_MAP_0,
                .map_bitmask = BMC150_ACCEL_INT_MAP_0_BIT_SLOPE,
                .en_reg = BMC150_ACCEL_REG_INT_EN_0,
                .en_bitmask =  BMC150_ACCEL_INT_EN_BIT_SLP_X |
                        BMC150_ACCEL_INT_EN_BIT_SLP_Y |
                        BMC150_ACCEL_INT_EN_BIT_SLP_Z
        },
        { /* fifo watermark interrupt */
                .map_reg = BMC150_ACCEL_REG_INT_MAP_1,
                .map_bitmask = BMC150_ACCEL_INT_MAP_1_BIT_FWM,
                .en_reg = BMC150_ACCEL_REG_INT_EN_1,
                .en_bitmask = BMC150_ACCEL_INT_EN_BIT_FWM_EN,
        },
};

static void bmc150_accel_interrupts_setup(struct iio_dev *indio_dev,
                                          struct bmc150_accel_data *data)
{
        int i;

        for (i = 0; i < BMC150_ACCEL_INTERRUPTS; i++)
                data->interrupts[i].info = &bmc150_accel_interrupts[i];
}

static int bmc150_accel_set_interrupt(struct bmc150_accel_data *data, int i,
                                      bool state)
{
        struct device *dev = regmap_get_device(data->regmap);
        struct bmc150_accel_interrupt *intr = &data->interrupts[i];
        const struct bmc150_accel_interrupt_info *info = intr->info;
        int ret;

        if (state) {
                if (atomic_inc_return(&intr->users) > 1)
                        return 0;
        } else {
                if (atomic_dec_return(&intr->users) > 0)
                        return 0;
        }

        /*
         * We will expect the enable and disable to do operation in reverse
         * order. This will happen here anyway, as our resume operation uses
         * sync mode runtime pm calls. The suspend operation will be delayed
         * by autosuspend delay.
         * So the disable operation will still happen in reverse order of
         * enable operation. When runtime pm is disabled the mode is always on,
         * so sequence doesn't matter.
         */
        ret = bmc150_accel_set_power_state(data, state);
        if (ret < 0)
                return ret;

        /* map the interrupt to the appropriate pins */
        ret = regmap_update_bits(data->regmap, info->map_reg, info->map_bitmask,
                                 (state ? info->map_bitmask : 0));
        if (ret < 0) {
                dev_err(dev, "Error updating reg_int_map\n");
                goto out_fix_power_state;
        }

        /* enable/disable the interrupt */
        ret = regmap_update_bits(data->regmap, info->en_reg, info->en_bitmask,
                                 (state ? info->en_bitmask : 0));
        if (ret < 0) {
                dev_err(dev, "Error updating reg_int_en\n");
                goto out_fix_power_state;
        }

        if (state)
                atomic_inc(&data->active_intr);
        else
                atomic_dec(&data->active_intr);

        return 0;

out_fix_power_state:
        bmc150_accel_set_power_state(data, false);
        return ret;
}

static int bmc150_accel_set_scale(struct bmc150_accel_data *data, int val)
{
        struct device *dev = regmap_get_device(data->regmap);
        int ret, i;

        for (i = 0; i < ARRAY_SIZE(data->chip_info->scale_table); ++i) {
                if (data->chip_info->scale_table[i].scale == val) {
                        ret = regmap_write(data->regmap,
                                     BMC150_ACCEL_REG_PMU_RANGE,
                                     data->chip_info->scale_table[i].reg_range);
                        if (ret < 0) {
                                dev_err(dev, "Error writing pmu_range\n");
                                return ret;
                        }

                        data->range = data->chip_info->scale_table[i].reg_range;
                        return 0;
                }
        }

        return -EINVAL;
}

static int bmc150_accel_get_temp(struct bmc150_accel_data *data, int *val)
{
        struct device *dev = regmap_get_device(data->regmap);
        int ret;
        unsigned int value;

        mutex_lock(&data->mutex);

        ret = regmap_read(data->regmap, BMC150_ACCEL_REG_TEMP, &value);
        if (ret < 0) {
                dev_err(dev, "Error reading reg_temp\n");
                mutex_unlock(&data->mutex);
                return ret;
        }
        *val = sign_extend32(value, 7);

        mutex_unlock(&data->mutex);

        return IIO_VAL_INT;
}

static int bmc150_accel_get_axis(struct bmc150_accel_data *data,
                                 struct iio_chan_spec const *chan,
                                 int *val)
{
        struct device *dev = regmap_get_device(data->regmap);
        int ret;
        int axis = chan->scan_index;
        __le16 raw_val;

        mutex_lock(&data->mutex);
        ret = bmc150_accel_set_power_state(data, true);
        if (ret < 0) {
                mutex_unlock(&data->mutex);
                return ret;
        }

        ret = regmap_bulk_read(data->regmap, BMC150_ACCEL_AXIS_TO_REG(axis),
                               &raw_val, sizeof(raw_val));
        if (ret < 0) {
                dev_err(dev, "Error reading axis %d\n", axis);
                bmc150_accel_set_power_state(data, false);
                mutex_unlock(&data->mutex);
                return ret;
        }
        *val = sign_extend32(le16_to_cpu(raw_val) >> chan->scan_type.shift,
                             chan->scan_type.realbits - 1);
        ret = bmc150_accel_set_power_state(data, false);
        mutex_unlock(&data->mutex);
        if (ret < 0)
                return ret;

        return IIO_VAL_INT;
}

static int bmc150_accel_read_raw(struct iio_dev *indio_dev,
                                 struct iio_chan_spec const *chan,
                                 int *val, int *val2, long mask)
{
        struct bmc150_accel_data *data = iio_priv(indio_dev);
        int ret;

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                switch (chan->type) {
                case IIO_TEMP:
                        return bmc150_accel_get_temp(data, val);
                case IIO_ACCEL:
                        if (iio_buffer_enabled(indio_dev))
                                return -EBUSY;
                        else
                                return bmc150_accel_get_axis(data, chan, val);
                default:
                        return -EINVAL;
                }
        case IIO_CHAN_INFO_OFFSET:
                if (chan->type == IIO_TEMP) {
                        *val = BMC150_ACCEL_TEMP_CENTER_VAL;
                        return IIO_VAL_INT;
                } else {
                        return -EINVAL;
                }
        case IIO_CHAN_INFO_SCALE:
                *val = 0;
                switch (chan->type) {
                case IIO_TEMP:
                        *val2 = 500000;
                        return IIO_VAL_INT_PLUS_MICRO;
                case IIO_ACCEL:
                {
                        int i;
                        const struct bmc150_scale_info *si;
                        int st_size = ARRAY_SIZE(data->chip_info->scale_table);

                        for (i = 0; i < st_size; ++i) {
                                si = &data->chip_info->scale_table[i];
                                if (si->reg_range == data->range) {
                                        *val2 = si->scale;
                                        return IIO_VAL_INT_PLUS_MICRO;
                                }
                        }
                        return -EINVAL;
                }
                default:
                        return -EINVAL;
                }
        case IIO_CHAN_INFO_SAMP_FREQ:
                mutex_lock(&data->mutex);
                ret = bmc150_accel_get_bw(data, val, val2);
                mutex_unlock(&data->mutex);
                return ret;
        default:
                return -EINVAL;
        }
}

static int bmc150_accel_write_raw(struct iio_dev *indio_dev,
                                  struct iio_chan_spec const *chan,
                                  int val, int val2, long mask)
{
        struct bmc150_accel_data *data = iio_priv(indio_dev);
        int ret;

        switch (mask) {
        case IIO_CHAN_INFO_SAMP_FREQ:
                mutex_lock(&data->mutex);
                ret = bmc150_accel_set_bw(data, val, val2);
                mutex_unlock(&data->mutex);
                break;
        case IIO_CHAN_INFO_SCALE:
                if (val)
                        return -EINVAL;

                mutex_lock(&data->mutex);
                ret = bmc150_accel_set_scale(data, val2);
                mutex_unlock(&data->mutex);
                return ret;
        default:
                ret = -EINVAL;
        }

        return ret;
}

static int bmc150_accel_read_event(struct iio_dev *indio_dev,
                                   const struct iio_chan_spec *chan,
                                   enum iio_event_type type,
                                   enum iio_event_direction dir,
                                   enum iio_event_info info,
                                   int *val, int *val2)
{
        struct bmc150_accel_data *data = iio_priv(indio_dev);

        *val2 = 0;
        switch (info) {
        case IIO_EV_INFO_VALUE:
                *val = data->slope_thres;
                break;
        case IIO_EV_INFO_PERIOD:
                *val = data->slope_dur;
                break;
        default:
                return -EINVAL;
        }

        return IIO_VAL_INT;
}

static int bmc150_accel_write_event(struct iio_dev *indio_dev,
                                    const struct iio_chan_spec *chan,
                                    enum iio_event_type type,
                                    enum iio_event_direction dir,
                                    enum iio_event_info info,
                                    int val, int val2)
{
        struct bmc150_accel_data *data = iio_priv(indio_dev);

        if (data->ev_enable_state)
                return -EBUSY;

        switch (info) {
        case IIO_EV_INFO_VALUE:
                data->slope_thres = val & BMC150_ACCEL_SLOPE_THRES_MASK;
                break;
        case IIO_EV_INFO_PERIOD:
                data->slope_dur = val & BMC150_ACCEL_SLOPE_DUR_MASK;
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static int bmc150_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 bmc150_accel_data *data = iio_priv(indio_dev);

        return data->ev_enable_state;
}

static int bmc150_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,
                                           int state)
{
        struct bmc150_accel_data *data = iio_priv(indio_dev);
        int ret;

        if (state == data->ev_enable_state)
                return 0;

        mutex_lock(&data->mutex);

        ret = bmc150_accel_set_interrupt(data, BMC150_ACCEL_INT_ANY_MOTION,
                                         state);
        if (ret < 0) {
                mutex_unlock(&data->mutex);
                return ret;
        }

        data->ev_enable_state = state;
        mutex_unlock(&data->mutex);

        return 0;
}

static int bmc150_accel_validate_trigger(struct iio_dev *indio_dev,
                                         struct iio_trigger *trig)
{
        struct bmc150_accel_data *data = iio_priv(indio_dev);
        int i;

        for (i = 0; i < BMC150_ACCEL_TRIGGERS; i++) {
                if (data->triggers[i].indio_trig == trig)
                        return 0;
        }

        return -EINVAL;
}

static ssize_t bmc150_accel_get_fifo_watermark(struct device *dev,
                                               struct device_attribute *attr,
                                               char *buf)
{
        struct iio_dev *indio_dev = dev_to_iio_dev(dev);
        struct bmc150_accel_data *data = iio_priv(indio_dev);
        int wm;

        mutex_lock(&data->mutex);
        wm = data->watermark;
        mutex_unlock(&data->mutex);

        return sprintf(buf, "%d\n", wm);
}

static ssize_t bmc150_accel_get_fifo_state(struct device *dev,
                                           struct device_attribute *attr,
                                           char *buf)
{
        struct iio_dev *indio_dev = dev_to_iio_dev(dev);
        struct bmc150_accel_data *data = iio_priv(indio_dev);
        bool state;

        mutex_lock(&data->mutex);
        state = data->fifo_mode;
        mutex_unlock(&data->mutex);

        return sprintf(buf, "%d\n", state);
}

static IIO_CONST_ATTR(hwfifo_watermark_min, "1");
static IIO_CONST_ATTR(hwfifo_watermark_max,
                      __stringify(BMC150_ACCEL_FIFO_LENGTH));
static IIO_DEVICE_ATTR(hwfifo_enabled, S_IRUGO,
                       bmc150_accel_get_fifo_state, NULL, 0);
static IIO_DEVICE_ATTR(hwfifo_watermark, S_IRUGO,
                       bmc150_accel_get_fifo_watermark, NULL, 0);

static const struct attribute *bmc150_accel_fifo_attributes[] = {
        &iio_const_attr_hwfifo_watermark_min.dev_attr.attr,
        &iio_const_attr_hwfifo_watermark_max.dev_attr.attr,
        &iio_dev_attr_hwfifo_watermark.dev_attr.attr,
        &iio_dev_attr_hwfifo_enabled.dev_attr.attr,
        NULL,
};

static int bmc150_accel_set_watermark(struct iio_dev *indio_dev, unsigned val)
{
        struct bmc150_accel_data *data = iio_priv(indio_dev);

        if (val > BMC150_ACCEL_FIFO_LENGTH)
                val = BMC150_ACCEL_FIFO_LENGTH;

        mutex_lock(&data->mutex);
        data->watermark = val;
        mutex_unlock(&data->mutex);

        return 0;
}

/*
 * We must read at least one full frame in one burst, otherwise the rest of the
 * frame data is discarded.
 */
static int bmc150_accel_fifo_transfer(struct bmc150_accel_data *data,
                                      char *buffer, int samples)
{
        struct device *dev = regmap_get_device(data->regmap);
        int sample_length = 3 * 2;
        int ret;
        int total_length = samples * sample_length;
        int i;
        size_t step = regmap_get_raw_read_max(data->regmap);

        if (!step || step > total_length)
                step = total_length;
        else if (step < total_length)
                step = sample_length;

        /*
         * Seems we have a bus with size limitation so we have to execute
         * multiple reads
         */
        for (i = 0; i < total_length; i += step) {
                ret = regmap_raw_read(data->regmap, BMC150_ACCEL_REG_FIFO_DATA,
                                      &buffer[i], step);
                if (ret)
                        break;
        }

        if (ret)
                dev_err(dev,
                        "Error transferring data from fifo in single steps of %zu\n",
                        step);

        return ret;
}

static int __bmc150_accel_fifo_flush(struct iio_dev *indio_dev,
                                     unsigned samples, bool irq)
{
        struct bmc150_accel_data *data = iio_priv(indio_dev);
        struct device *dev = regmap_get_device(data->regmap);
        int ret, i;
        u8 count;
        u16 buffer[BMC150_ACCEL_FIFO_LENGTH * 3];
        int64_t tstamp;
        uint64_t sample_period;
        unsigned int val;

        ret = regmap_read(data->regmap, BMC150_ACCEL_REG_FIFO_STATUS, &val);
        if (ret < 0) {
                dev_err(dev, "Error reading reg_fifo_status\n");
                return ret;
        }

        count = val & 0x7F;

        if (!count)
                return 0;

        /*
         * If we getting called from IRQ handler we know the stored timestamp is
         * fairly accurate for the last stored sample. Otherwise, if we are
         * called as a result of a read operation from userspace and hence
         * before the watermark interrupt was triggered, take a timestamp
         * now. We can fall anywhere in between two samples so the error in this
         * case is at most one sample period.
         */
        if (!irq) {
                data->old_timestamp = data->timestamp;
                data->timestamp = iio_get_time_ns(indio_dev);
        }

        /*
         * Approximate timestamps for each of the sample based on the sampling
         * frequency, timestamp for last sample and number of samples.
         *
         * Note that we can't use the current bandwidth settings to compute the
         * sample period because the sample rate varies with the device
         * (e.g. between 31.70ms to 32.20ms for a bandwidth of 15.63HZ). That
         * small variation adds when we store a large number of samples and
         * creates significant jitter between the last and first samples in
         * different batches (e.g. 32ms vs 21ms).
         *
         * To avoid this issue we compute the actual sample period ourselves
         * based on the timestamp delta between the last two flush operations.
         */
        sample_period = (data->timestamp - data->old_timestamp);
        do_div(sample_period, count);
        tstamp = data->timestamp - (count - 1) * sample_period;

        if (samples && count > samples)
                count = samples;

        ret = bmc150_accel_fifo_transfer(data, (u8 *)buffer, count);
        if (ret)
                return ret;

        /*
         * Ideally we want the IIO core to handle the demux when running in fifo
         * mode but not when running in triggered buffer mode. Unfortunately
         * this does not seem to be possible, so stick with driver demux for
         * now.
         */
        for (i = 0; i < count; i++) {
                u16 sample[8];
                int j, bit;

                j = 0;
                for_each_set_bit(bit, indio_dev->active_scan_mask,
                                 indio_dev->masklength)
                        memcpy(&sample[j++], &buffer[i * 3 + bit], 2);

                iio_push_to_buffers_with_timestamp(indio_dev, sample, tstamp);

                tstamp += sample_period;
        }

        return count;
}

static int bmc150_accel_fifo_flush(struct iio_dev *indio_dev, unsigned samples)
{
        struct bmc150_accel_data *data = iio_priv(indio_dev);
        int ret;

        mutex_lock(&data->mutex);
        ret = __bmc150_accel_fifo_flush(indio_dev, samples, false);
        mutex_unlock(&data->mutex);

        return ret;
}

static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
                "15.620000 31.260000 62.50000 125 250 500 1000 2000");

static struct attribute *bmc150_accel_attributes[] = {
        &iio_const_attr_sampling_frequency_available.dev_attr.attr,
        NULL,
};

static const struct attribute_group bmc150_accel_attrs_group = {
        .attrs = bmc150_accel_attributes,
};

static const struct iio_event_spec bmc150_accel_event = {
                .type = IIO_EV_TYPE_ROC,
                .dir = IIO_EV_DIR_EITHER,
                .mask_separate = BIT(IIO_EV_INFO_VALUE) |
                                 BIT(IIO_EV_INFO_ENABLE) |
                                 BIT(IIO_EV_INFO_PERIOD)
};

#define BMC150_ACCEL_CHANNEL(_axis, bits) {                             \
        .type = IIO_ACCEL,                                              \
        .modified = 1,                                                  \
        .channel2 = IIO_MOD_##_axis,                                    \
        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),                   \
        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |          \
                                BIT(IIO_CHAN_INFO_SAMP_FREQ),           \
        .scan_index = AXIS_##_axis,                                     \
        .scan_type = {                                                  \
                .sign = 's',                                            \
                .realbits = (bits),                                     \
                .storagebits = 16,                                      \
                .shift = 16 - (bits),                                   \
                .endianness = IIO_LE,                                   \
        },                                                              \
        .event_spec = &bmc150_accel_event,                              \
        .num_event_specs = 1                                            \
}

#define BMC150_ACCEL_CHANNELS(bits) {                                   \
        {                                                               \
                .type = IIO_TEMP,                                       \
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |          \
                                      BIT(IIO_CHAN_INFO_SCALE) |        \
                                      BIT(IIO_CHAN_INFO_OFFSET),        \
                .scan_index = -1,                                       \
        },                                                              \
        BMC150_ACCEL_CHANNEL(X, bits),                                  \
        BMC150_ACCEL_CHANNEL(Y, bits),                                  \
        BMC150_ACCEL_CHANNEL(Z, bits),                                  \
        IIO_CHAN_SOFT_TIMESTAMP(3),                                     \
}

static const struct iio_chan_spec bma222e_accel_channels[] =
        BMC150_ACCEL_CHANNELS(8);
static const struct iio_chan_spec bma250e_accel_channels[] =
        BMC150_ACCEL_CHANNELS(10);
static const struct iio_chan_spec bmc150_accel_channels[] =
        BMC150_ACCEL_CHANNELS(12);
static const struct iio_chan_spec bma280_accel_channels[] =
        BMC150_ACCEL_CHANNELS(14);

static const struct bmc150_accel_chip_info bmc150_accel_chip_info_tbl[] = {
        [bmc150] = {
                .name = "BMC150A",
                .chip_id = 0xFA,
                .channels = bmc150_accel_channels,
                .num_channels = ARRAY_SIZE(bmc150_accel_channels),
                .scale_table = { {9610, BMC150_ACCEL_DEF_RANGE_2G},
                                 {19122, BMC150_ACCEL_DEF_RANGE_4G},
                                 {38344, BMC150_ACCEL_DEF_RANGE_8G},
                                 {76590, BMC150_ACCEL_DEF_RANGE_16G} },
        },
        [bmi055] = {
                .name = "BMI055A",
                .chip_id = 0xFA,
                .channels = bmc150_accel_channels,
                .num_channels = ARRAY_SIZE(bmc150_accel_channels),
                .scale_table = { {9610, BMC150_ACCEL_DEF_RANGE_2G},
                                 {19122, BMC150_ACCEL_DEF_RANGE_4G},
                                 {38344, BMC150_ACCEL_DEF_RANGE_8G},
                                 {76590, BMC150_ACCEL_DEF_RANGE_16G} },
        },
        [bma255] = {
                .name = "BMA0255",
                .chip_id = 0xFA,
                .channels = bmc150_accel_channels,
                .num_channels = ARRAY_SIZE(bmc150_accel_channels),
                .scale_table = { {9610, BMC150_ACCEL_DEF_RANGE_2G},
                                 {19122, BMC150_ACCEL_DEF_RANGE_4G},
                                 {38344, BMC150_ACCEL_DEF_RANGE_8G},
                                 {76590, BMC150_ACCEL_DEF_RANGE_16G} },
        },
        [bma250e] = {
                .name = "BMA250E",
                .chip_id = 0xF9,
                .channels = bma250e_accel_channels,
                .num_channels = ARRAY_SIZE(bma250e_accel_channels),
                .scale_table = { {38344, BMC150_ACCEL_DEF_RANGE_2G},
                                 {76590, BMC150_ACCEL_DEF_RANGE_4G},
                                 {153277, BMC150_ACCEL_DEF_RANGE_8G},
                                 {306457, BMC150_ACCEL_DEF_RANGE_16G} },
        },
        [bma222e] = {
                .name = "BMA222E",
                .chip_id = 0xF8,
                .channels = bma222e_accel_channels,
                .num_channels = ARRAY_SIZE(bma222e_accel_channels),
                .scale_table = { {153277, BMC150_ACCEL_DEF_RANGE_2G},
                                 {306457, BMC150_ACCEL_DEF_RANGE_4G},
                                 {612915, BMC150_ACCEL_DEF_RANGE_8G},
                                 {1225831, BMC150_ACCEL_DEF_RANGE_16G} },
        },
        [bma280] = {
                .name = "BMA0280",
                .chip_id = 0xFB,
                .channels = bma280_accel_channels,
                .num_channels = ARRAY_SIZE(bma280_accel_channels),
                .scale_table = { {2392, BMC150_ACCEL_DEF_RANGE_2G},
                                 {4785, BMC150_ACCEL_DEF_RANGE_4G},
                                 {9581, BMC150_ACCEL_DEF_RANGE_8G},
                                 {19152, BMC150_ACCEL_DEF_RANGE_16G} },
        },
};

static const struct iio_info bmc150_accel_info = {
        .attrs                  = &bmc150_accel_attrs_group,
        .read_raw               = bmc150_accel_read_raw,
        .write_raw              = bmc150_accel_write_raw,
        .read_event_value       = bmc150_accel_read_event,
        .write_event_value      = bmc150_accel_write_event,
        .write_event_config     = bmc150_accel_write_event_config,
        .read_event_config      = bmc150_accel_read_event_config,
        .driver_module          = THIS_MODULE,
};

static const struct iio_info bmc150_accel_info_fifo = {
        .attrs                  = &bmc150_accel_attrs_group,
        .read_raw               = bmc150_accel_read_raw,
        .write_raw              = bmc150_accel_write_raw,
        .read_event_value       = bmc150_accel_read_event,
        .write_event_value      = bmc150_accel_write_event,
        .write_event_config     = bmc150_accel_write_event_config,
        .read_event_config      = bmc150_accel_read_event_config,
        .validate_trigger       = bmc150_accel_validate_trigger,
        .hwfifo_set_watermark   = bmc150_accel_set_watermark,
        .hwfifo_flush_to_buffer = bmc150_accel_fifo_flush,
        .driver_module          = THIS_MODULE,
};

static const unsigned long bmc150_accel_scan_masks[] = {
                                        BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
                                        0};

static irqreturn_t bmc150_accel_trigger_handler(int irq, void *p)
{
        struct iio_poll_func *pf = p;
        struct iio_dev *indio_dev = pf->indio_dev;
        struct bmc150_accel_data *data = iio_priv(indio_dev);
        int ret;

        mutex_lock(&data->mutex);
        ret = regmap_bulk_read(data->regmap, BMC150_ACCEL_REG_XOUT_L,
                               data->buffer, AXIS_MAX * 2);
        mutex_unlock(&data->mutex);
        if (ret < 0)
                goto err_read;

        iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
                                           pf->timestamp);
err_read:
        iio_trigger_notify_done(indio_dev->trig);

        return IRQ_HANDLED;
}

static int bmc150_accel_trig_try_reen(struct iio_trigger *trig)
{
        struct bmc150_accel_trigger *t = iio_trigger_get_drvdata(trig);
        struct bmc150_accel_data *data = t->data;
        struct device *dev = regmap_get_device(data->regmap);
        int ret;

        /* new data interrupts don't need ack */
        if (t == &t->data->triggers[BMC150_ACCEL_TRIGGER_DATA_READY])
                return 0;

        mutex_lock(&data->mutex);
        /* clear any latched interrupt */
        ret = regmap_write(data->regmap, BMC150_ACCEL_REG_INT_RST_LATCH,
                           BMC150_ACCEL_INT_MODE_LATCH_INT |
                           BMC150_ACCEL_INT_MODE_LATCH_RESET);
        mutex_unlock(&data->mutex);
        if (ret < 0) {
                dev_err(dev, "Error writing reg_int_rst_latch\n");
                return ret;
        }

        return 0;
}

static int bmc150_accel_trigger_set_state(struct iio_trigger *trig,
                                          bool state)
{
        struct bmc150_accel_trigger *t = iio_trigger_get_drvdata(trig);
        struct bmc150_accel_data *data = t->data;
        int ret;

        mutex_lock(&data->mutex);

        if (t->enabled == state) {
                mutex_unlock(&data->mutex);
                return 0;
        }

        if (t->setup) {
                ret = t->setup(t, state);
                if (ret < 0) {
                        mutex_unlock(&data->mutex);
                        return ret;
                }
        }

        ret = bmc150_accel_set_interrupt(data, t->intr, state);
        if (ret < 0) {
                mutex_unlock(&data->mutex);
                return ret;
        }

        t->enabled = state;

        mutex_unlock(&data->mutex);

        return ret;
}

static const struct iio_trigger_ops bmc150_accel_trigger_ops = {
        .set_trigger_state = bmc150_accel_trigger_set_state,
        .try_reenable = bmc150_accel_trig_try_reen,
        .owner = THIS_MODULE,
};

static int bmc150_accel_handle_roc_event(struct iio_dev *indio_dev)
{
        struct bmc150_accel_data *data = iio_priv(indio_dev);
        struct device *dev = regmap_get_device(data->regmap);
        int dir;
        int ret;
        unsigned int val;

        ret = regmap_read(data->regmap, BMC150_ACCEL_REG_INT_STATUS_2, &val);
        if (ret < 0) {
                dev_err(dev, "Error reading reg_int_status_2\n");
                return ret;
        }

        if (val & BMC150_ACCEL_ANY_MOTION_BIT_SIGN)
                dir = IIO_EV_DIR_FALLING;
        else
                dir = IIO_EV_DIR_RISING;

        if (val & BMC150_ACCEL_ANY_MOTION_BIT_X)
                iio_push_event(indio_dev,
                               IIO_MOD_EVENT_CODE(IIO_ACCEL,
                                                  0,
                                                  IIO_MOD_X,
                                                  IIO_EV_TYPE_ROC,
                                                  dir),
                               data->timestamp);

        if (val & BMC150_ACCEL_ANY_MOTION_BIT_Y)
                iio_push_event(indio_dev,
                               IIO_MOD_EVENT_CODE(IIO_ACCEL,
                                                  0,
                                                  IIO_MOD_Y,
                                                  IIO_EV_TYPE_ROC,
                                                  dir),
                               data->timestamp);

        if (val & BMC150_ACCEL_ANY_MOTION_BIT_Z)
                iio_push_event(indio_dev,
                               IIO_MOD_EVENT_CODE(IIO_ACCEL,
                                                  0,
                                                  IIO_MOD_Z,
                                                  IIO_EV_TYPE_ROC,
                                                  dir),
                               data->timestamp);

        return ret;
}

static irqreturn_t bmc150_accel_irq_thread_handler(int irq, void *private)
{
        struct iio_dev *indio_dev = private;
        struct bmc150_accel_data *data = iio_priv(indio_dev);
        struct device *dev = regmap_get_device(data->regmap);
        bool ack = false;
        int ret;

        mutex_lock(&data->mutex);

        if (data->fifo_mode) {
                ret = __bmc150_accel_fifo_flush(indio_dev,
                                                BMC150_ACCEL_FIFO_LENGTH, true);
                if (ret > 0)
                        ack = true;
        }

        if (data->ev_enable_state) {
                ret = bmc150_accel_handle_roc_event(indio_dev);
                if (ret > 0)
                        ack = true;
        }

        if (ack) {
                ret = regmap_write(data->regmap, BMC150_ACCEL_REG_INT_RST_LATCH,
                                   BMC150_ACCEL_INT_MODE_LATCH_INT |
                                   BMC150_ACCEL_INT_MODE_LATCH_RESET);
                if (ret)
                        dev_err(dev, "Error writing reg_int_rst_latch\n");

                ret = IRQ_HANDLED;
        } else {
                ret = IRQ_NONE;
        }

        mutex_unlock(&data->mutex);

        return ret;
}

static irqreturn_t bmc150_accel_irq_handler(int irq, void *private)
{
        struct iio_dev *indio_dev = private;
        struct bmc150_accel_data *data = iio_priv(indio_dev);
        bool ack = false;
        int i;

        data->old_timestamp = data->timestamp;
        data->timestamp = iio_get_time_ns(indio_dev);

        for (i = 0; i < BMC150_ACCEL_TRIGGERS; i++) {
                if (data->triggers[i].enabled) {
                        iio_trigger_poll(data->triggers[i].indio_trig);
                        ack = true;
                        break;
                }
        }

        if (data->ev_enable_state || data->fifo_mode)
                return IRQ_WAKE_THREAD;

        if (ack)
                return IRQ_HANDLED;

        return IRQ_NONE;
}

static const struct {
        int intr;
        const char *name;
        int (*setup)(struct bmc150_accel_trigger *t, bool state);
} bmc150_accel_triggers[BMC150_ACCEL_TRIGGERS] = {
        {
                .intr = 0,
                .name = "%s-dev%d",
        },
        {
                .intr = 1,
                .name = "%s-any-motion-dev%d",
                .setup = bmc150_accel_any_motion_setup,
        },
};

static void bmc150_accel_unregister_triggers(struct bmc150_accel_data *data,
                                             int from)
{
        int i;

        for (i = from; i >= 0; i--) {
                if (data->triggers[i].indio_trig) {
                        iio_trigger_unregister(data->triggers[i].indio_trig);
                        data->triggers[i].indio_trig = NULL;
                }
        }
}

static int bmc150_accel_triggers_setup(struct iio_dev *indio_dev,
                                       struct bmc150_accel_data *data)
{
        struct device *dev = regmap_get_device(data->regmap);
        int i, ret;

        for (i = 0; i < BMC150_ACCEL_TRIGGERS; i++) {
                struct bmc150_accel_trigger *t = &data->triggers[i];

                t->indio_trig = devm_iio_trigger_alloc(dev,
                                        bmc150_accel_triggers[i].name,
                                                       indio_dev->name,
                                                       indio_dev->id);
                if (!t->indio_trig) {
                        ret = -ENOMEM;
                        break;
                }

                t->indio_trig->dev.parent = dev;
                t->indio_trig->ops = &bmc150_accel_trigger_ops;
                t->intr = bmc150_accel_triggers[i].intr;
                t->data = data;
                t->setup = bmc150_accel_triggers[i].setup;
                iio_trigger_set_drvdata(t->indio_trig, t);

                ret = iio_trigger_register(t->indio_trig);
                if (ret)
                        break;
        }

        if (ret)
                bmc150_accel_unregister_triggers(data, i - 1);

        return ret;
}

#define BMC150_ACCEL_FIFO_MODE_STREAM          0x80
#define BMC150_ACCEL_FIFO_MODE_FIFO            0x40
#define BMC150_ACCEL_FIFO_MODE_BYPASS          0x00

static int bmc150_accel_fifo_set_mode(struct bmc150_accel_data *data)
{
        struct device *dev = regmap_get_device(data->regmap);
        u8 reg = BMC150_ACCEL_REG_FIFO_CONFIG1;
        int ret;

        ret = regmap_write(data->regmap, reg, data->fifo_mode);
        if (ret < 0) {
                dev_err(dev, "Error writing reg_fifo_config1\n");
                return ret;
        }

        if (!data->fifo_mode)
                return 0;

        ret = regmap_write(data->regmap, BMC150_ACCEL_REG_FIFO_CONFIG0,
                           data->watermark);
        if (ret < 0)
                dev_err(dev, "Error writing reg_fifo_config0\n");

        return ret;
}

static int bmc150_accel_buffer_preenable(struct iio_dev *indio_dev)
{
        struct bmc150_accel_data *data = iio_priv(indio_dev);

        return bmc150_accel_set_power_state(data, true);
}

static int bmc150_accel_buffer_postenable(struct iio_dev *indio_dev)
{
        struct bmc150_accel_data *data = iio_priv(indio_dev);
        int ret = 0;

        if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED)
                return iio_triggered_buffer_postenable(indio_dev);

        mutex_lock(&data->mutex);

        if (!data->watermark)
                goto out;

        ret = bmc150_accel_set_interrupt(data, BMC150_ACCEL_INT_WATERMARK,
                                         true);
        if (ret)
                goto out;

        data->fifo_mode = BMC150_ACCEL_FIFO_MODE_FIFO;

        ret = bmc150_accel_fifo_set_mode(data);
        if (ret) {
                data->fifo_mode = 0;
                bmc150_accel_set_interrupt(data, BMC150_ACCEL_INT_WATERMARK,
                                           false);
        }

out:
        mutex_unlock(&data->mutex);

        return ret;
}

static int bmc150_accel_buffer_predisable(struct iio_dev *indio_dev)
{
        struct bmc150_accel_data *data = iio_priv(indio_dev);

        if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED)
                return iio_triggered_buffer_predisable(indio_dev);

        mutex_lock(&data->mutex);

        if (!data->fifo_mode)
                goto out;

        bmc150_accel_set_interrupt(data, BMC150_ACCEL_INT_WATERMARK, false);
        __bmc150_accel_fifo_flush(indio_dev, BMC150_ACCEL_FIFO_LENGTH, false);
        data->fifo_mode = 0;
        bmc150_accel_fifo_set_mode(data);

out:
        mutex_unlock(&data->mutex);

        return 0;
}

static int bmc150_accel_buffer_postdisable(struct iio_dev *indio_dev)
{
        struct bmc150_accel_data *data = iio_priv(indio_dev);

        return bmc150_accel_set_power_state(data, false);
}

static const struct iio_buffer_setup_ops bmc150_accel_buffer_ops = {
        .preenable = bmc150_accel_buffer_preenable,
        .postenable = bmc150_accel_buffer_postenable,
        .predisable = bmc150_accel_buffer_predisable,
        .postdisable = bmc150_accel_buffer_postdisable,
};

static int bmc150_accel_chip_init(struct bmc150_accel_data *data)
{
        struct device *dev = regmap_get_device(data->regmap);
        int ret, i;
        unsigned int val;

        /*
         * Reset chip to get it in a known good state. A delay of 1.8ms after
         * reset is required according to the data sheets of supported chips.
         */
        regmap_write(data->regmap, BMC150_ACCEL_REG_RESET,
                     BMC150_ACCEL_RESET_VAL);
        usleep_range(1800, 2500);

        ret = regmap_read(data->regmap, BMC150_ACCEL_REG_CHIP_ID, &val);
        if (ret < 0) {
                dev_err(dev, "Error: Reading chip id\n");
                return ret;
        }

        dev_dbg(dev, "Chip Id %x\n", val);
        for (i = 0; i < ARRAY_SIZE(bmc150_accel_chip_info_tbl); i++) {
                if (bmc150_accel_chip_info_tbl[i].chip_id == val) {
                        data->chip_info = &bmc150_accel_chip_info_tbl[i];
                        break;
                }
        }

        if (!data->chip_info) {
                dev_err(dev, "Invalid chip %x\n", val);
                return -ENODEV;
        }

        ret = bmc150_accel_set_mode(data, BMC150_ACCEL_SLEEP_MODE_NORMAL, 0);
        if (ret < 0)
                return ret;

        /* Set Bandwidth */
        ret = bmc150_accel_set_bw(data, BMC150_ACCEL_DEF_BW, 0);
        if (ret < 0)
                return ret;

        /* Set Default Range */
        ret = regmap_write(data->regmap, BMC150_ACCEL_REG_PMU_RANGE,
                           BMC150_ACCEL_DEF_RANGE_4G);
        if (ret < 0) {
                dev_err(dev, "Error writing reg_pmu_range\n");
                return ret;
        }

        data->range = BMC150_ACCEL_DEF_RANGE_4G;

        /* Set default slope duration and thresholds */
        data->slope_thres = BMC150_ACCEL_DEF_SLOPE_THRESHOLD;
        data->slope_dur = BMC150_ACCEL_DEF_SLOPE_DURATION;
        ret = bmc150_accel_update_slope(data);
        if (ret < 0)
                return ret;

        /* Set default as latched interrupts */
        ret = regmap_write(data->regmap, BMC150_ACCEL_REG_INT_RST_LATCH,
                           BMC150_ACCEL_INT_MODE_LATCH_INT |
                           BMC150_ACCEL_INT_MODE_LATCH_RESET);
        if (ret < 0) {
                dev_err(dev, "Error writing reg_int_rst_latch\n");
                return ret;
        }

        return 0;
}

int bmc150_accel_core_probe(struct device *dev, struct regmap *regmap, int irq,
                            const char *name, bool block_supported)
{
        struct bmc150_accel_data *data;
        struct iio_dev *indio_dev;
        int ret;

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

        data = iio_priv(indio_dev);
        dev_set_drvdata(dev, indio_dev);
        data->irq = irq;

        data->regmap = regmap;

        ret = bmc150_accel_chip_init(data);
        if (ret < 0)
                return ret;

        mutex_init(&data->mutex);

        indio_dev->dev.parent = dev;
        indio_dev->channels = data->chip_info->channels;
        indio_dev->num_channels = data->chip_info->num_channels;
        indio_dev->name = name ? name : data->chip_info->name;
        indio_dev->available_scan_masks = bmc150_accel_scan_masks;
        indio_dev->modes = INDIO_DIRECT_MODE;
        indio_dev->info = &bmc150_accel_info;

        ret = iio_triggered_buffer_setup(indio_dev,
                                         &iio_pollfunc_store_time,
                                         bmc150_accel_trigger_handler,
                                         &bmc150_accel_buffer_ops);
        if (ret < 0) {
                dev_err(dev, "Failed: iio triggered buffer setup\n");
                return ret;
        }

        if (data->irq > 0) {
                ret = devm_request_threaded_irq(
                                                dev, data->irq,
                                                bmc150_accel_irq_handler,
                                                bmc150_accel_irq_thread_handler,
                                                IRQF_TRIGGER_RISING,
                                                BMC150_ACCEL_IRQ_NAME,
                                                indio_dev);
                if (ret)
                        goto err_buffer_cleanup;

                /*
                 * Set latched mode interrupt. While certain interrupts are
                 * non-latched regardless of this settings (e.g. new data) we
                 * want to use latch mode when we can to prevent interrupt
                 * flooding.
                 */
                ret = regmap_write(data->regmap, BMC150_ACCEL_REG_INT_RST_LATCH,
                                   BMC150_ACCEL_INT_MODE_LATCH_RESET);
                if (ret < 0) {
                        dev_err(dev, "Error writing reg_int_rst_latch\n");
                        goto err_buffer_cleanup;
                }

                bmc150_accel_interrupts_setup(indio_dev, data);

                ret = bmc150_accel_triggers_setup(indio_dev, data);
                if (ret)
                        goto err_buffer_cleanup;

                if (block_supported) {
                        indio_dev->modes |= INDIO_BUFFER_SOFTWARE;
                        indio_dev->info = &bmc150_accel_info_fifo;
                        iio_buffer_set_attrs(indio_dev->buffer,
                                             bmc150_accel_fifo_attributes);
                }
        }

        ret = pm_runtime_set_active(dev);
        if (ret)
                goto err_trigger_unregister;

        pm_runtime_enable(dev);
        pm_runtime_set_autosuspend_delay(dev, BMC150_AUTO_SUSPEND_DELAY_MS);
        pm_runtime_use_autosuspend(dev);

        ret = iio_device_register(indio_dev);
        if (ret < 0) {
                dev_err(dev, "Unable to register iio device\n");
                goto err_trigger_unregister;
        }

        return 0;

err_trigger_unregister:
        bmc150_accel_unregister_triggers(data, BMC150_ACCEL_TRIGGERS - 1);
err_buffer_cleanup:
        iio_triggered_buffer_cleanup(indio_dev);

        return ret;
}
EXPORT_SYMBOL_GPL(bmc150_accel_core_probe);

int bmc150_accel_core_remove(struct device *dev)
{
        struct iio_dev *indio_dev = dev_get_drvdata(dev);
        struct bmc150_accel_data *data = iio_priv(indio_dev);

        iio_device_unregister(indio_dev);

        pm_runtime_disable(dev);
        pm_runtime_set_suspended(dev);
        pm_runtime_put_noidle(dev);

        bmc150_accel_unregister_triggers(data, BMC150_ACCEL_TRIGGERS - 1);

        iio_triggered_buffer_cleanup(indio_dev);

        mutex_lock(&data->mutex);
        bmc150_accel_set_mode(data, BMC150_ACCEL_SLEEP_MODE_DEEP_SUSPEND, 0);
        mutex_unlock(&data->mutex);

        return 0;
}
EXPORT_SYMBOL_GPL(bmc150_accel_core_remove);

#ifdef CONFIG_PM_SLEEP
static int bmc150_accel_suspend(struct device *dev)
{
        struct iio_dev *indio_dev = dev_get_drvdata(dev);
        struct bmc150_accel_data *data = iio_priv(indio_dev);

        mutex_lock(&data->mutex);
        bmc150_accel_set_mode(data, BMC150_ACCEL_SLEEP_MODE_SUSPEND, 0);
        mutex_unlock(&data->mutex);

        return 0;
}

static int bmc150_accel_resume(struct device *dev)
{
        struct iio_dev *indio_dev = dev_get_drvdata(dev);
        struct bmc150_accel_data *data = iio_priv(indio_dev);

        mutex_lock(&data->mutex);
        if (atomic_read(&data->active_intr))
                bmc150_accel_set_mode(data, BMC150_ACCEL_SLEEP_MODE_NORMAL, 0);
        bmc150_accel_fifo_set_mode(data);
        mutex_unlock(&data->mutex);

        return 0;
}
#endif

#ifdef CONFIG_PM
static int bmc150_accel_runtime_suspend(struct device *dev)
{
        struct iio_dev *indio_dev = dev_get_drvdata(dev);
        struct bmc150_accel_data *data = iio_priv(indio_dev);
        int ret;

        dev_dbg(dev,  __func__);
        ret = bmc150_accel_set_mode(data, BMC150_ACCEL_SLEEP_MODE_SUSPEND, 0);
        if (ret < 0)
                return -EAGAIN;

        return 0;
}

static int bmc150_accel_runtime_resume(struct device *dev)
{
        struct iio_dev *indio_dev = dev_get_drvdata(dev);
        struct bmc150_accel_data *data = iio_priv(indio_dev);
        int ret;
        int sleep_val;

        dev_dbg(dev,  __func__);

        ret = bmc150_accel_set_mode(data, BMC150_ACCEL_SLEEP_MODE_NORMAL, 0);
        if (ret < 0)
                return ret;
        ret = bmc150_accel_fifo_set_mode(data);
        if (ret < 0)
                return ret;

        sleep_val = bmc150_accel_get_startup_times(data);
        if (sleep_val < 20)
                usleep_range(sleep_val * 1000, 20000);
        else
                msleep_interruptible(sleep_val);

        return 0;
}
#endif

const struct dev_pm_ops bmc150_accel_pm_ops = {
        SET_SYSTEM_SLEEP_PM_OPS(bmc150_accel_suspend, bmc150_accel_resume)
        SET_RUNTIME_PM_OPS(bmc150_accel_runtime_suspend,
                           bmc150_accel_runtime_resume, NULL)
};
EXPORT_SYMBOL_GPL(bmc150_accel_pm_ops);

MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("BMC150 accelerometer driver");