// SPDX-License-Identifier: GPL-2.0-only
/*
 * Support for Lite-On LTR501 and similar ambient light and proximity sensors.
 *
 * Copyright 2014 Peter Meerwald <pmeerw@pmeerw.net>
 *
 * 7-bit I2C slave address 0x23
 *
 * TODO: IR LED characteristics
 */

#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>

#include <linux/iio/iio.h>
#include <linux/iio/events.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/buffer.h>
#include <linux/iio/triggered_buffer.h>

#define LTR501_ALS_CONTR 0x80 /* ALS operation mode, SW reset */
#define LTR501_PS_CONTR 0x81 /* PS operation mode */
#define LTR501_PS_MEAS_RATE 0x84 /* measurement rate*/
#define LTR501_ALS_MEAS_RATE 0x85 /* ALS integ time, measurement rate*/
#define LTR501_PART_ID 0x86
#define LTR501_MANUFAC_ID 0x87
#define LTR501_ALS_DATA1 0x88 /* 16-bit, little endian */
#define LTR501_ALS_DATA1_UPPER 0x89 /* upper 8 bits of LTR501_ALS_DATA1 */
#define LTR501_ALS_DATA0 0x8a /* 16-bit, little endian */
#define LTR501_ALS_DATA0_UPPER 0x8b /* upper 8 bits of LTR501_ALS_DATA0 */
#define LTR501_ALS_PS_STATUS 0x8c
#define LTR501_PS_DATA 0x8d /* 16-bit, little endian */
#define LTR501_PS_DATA_UPPER 0x8e /* upper 8 bits of LTR501_PS_DATA */
#define LTR501_INTR 0x8f /* output mode, polarity, mode */
#define LTR501_PS_THRESH_UP 0x90 /* 11 bit, ps upper threshold */
#define LTR501_PS_THRESH_LOW 0x92 /* 11 bit, ps lower threshold */
#define LTR501_ALS_THRESH_UP 0x97 /* 16 bit, ALS upper threshold */
#define LTR501_ALS_THRESH_LOW 0x99 /* 16 bit, ALS lower threshold */
#define LTR501_INTR_PRST 0x9e /* ps thresh, als thresh */
#define LTR501_MAX_REG 0x9f

#define LTR501_ALS_CONTR_SW_RESET BIT(2)
#define LTR501_CONTR_PS_GAIN_MASK (BIT(3) | BIT(2))
#define LTR501_CONTR_PS_GAIN_SHIFT 2
#define LTR501_CONTR_ALS_GAIN_MASK BIT(3)
#define LTR501_CONTR_ACTIVE BIT(1)

#define LTR501_STATUS_ALS_INTR BIT(3)
#define LTR501_STATUS_ALS_RDY BIT(2)
#define LTR501_STATUS_PS_INTR BIT(1)
#define LTR501_STATUS_PS_RDY BIT(0)

#define LTR501_PS_DATA_MASK 0x7ff
#define LTR501_PS_THRESH_MASK 0x7ff
#define LTR501_ALS_THRESH_MASK 0xffff

#define LTR501_ALS_DEF_PERIOD 500000
#define LTR501_PS_DEF_PERIOD 100000

#define LTR501_LUX_CONV(vis_coeff, vis_data, ir_coeff, ir_data) \
                        ((vis_coeff * vis_data) - (ir_coeff * ir_data))

static const int int_time_mapping[] = {100000, 50000, 200000, 400000};

static const struct reg_field reg_field_it =
                                REG_FIELD(LTR501_ALS_MEAS_RATE, 3, 4);
static const struct reg_field reg_field_als_intr =
                                REG_FIELD(LTR501_INTR, 1, 1);
static const struct reg_field reg_field_ps_intr =
                                REG_FIELD(LTR501_INTR, 0, 0);
static const struct reg_field reg_field_als_rate =
                                REG_FIELD(LTR501_ALS_MEAS_RATE, 0, 2);
static const struct reg_field reg_field_ps_rate =
                                REG_FIELD(LTR501_PS_MEAS_RATE, 0, 3);
static const struct reg_field reg_field_als_prst =
                                REG_FIELD(LTR501_INTR_PRST, 0, 3);
static const struct reg_field reg_field_ps_prst =
                                REG_FIELD(LTR501_INTR_PRST, 4, 7);

struct ltr501_samp_table {
        int freq_val;  /* repetition frequency in micro HZ*/
        int time_val; /* repetition rate in micro seconds */
};

#define LTR501_RESERVED_GAIN -1

enum {
        ltr501 = 0,
        ltr559,
        ltr301,
        ltr303,
};

struct ltr501_gain {
        int scale;
        int uscale;
};

static const struct ltr501_gain ltr501_als_gain_tbl[] = {
        {1, 0},
        {0, 5000},
};

static const struct ltr501_gain ltr559_als_gain_tbl[] = {
        {1, 0},
        {0, 500000},
        {0, 250000},
        {0, 125000},
        {LTR501_RESERVED_GAIN, LTR501_RESERVED_GAIN},
        {LTR501_RESERVED_GAIN, LTR501_RESERVED_GAIN},
        {0, 20000},
        {0, 10000},
};

static const struct ltr501_gain ltr501_ps_gain_tbl[] = {
        {1, 0},
        {0, 250000},
        {0, 125000},
        {0, 62500},
};

static const struct ltr501_gain ltr559_ps_gain_tbl[] = {
        {0, 62500}, /* x16 gain */
        {0, 31250}, /* x32 gain */
        {0, 15625}, /* bits X1 are for x64 gain */
        {0, 15624},
};

struct ltr501_chip_info {
        u8 partid;
        const struct ltr501_gain *als_gain;
        int als_gain_tbl_size;
        const struct ltr501_gain *ps_gain;
        int ps_gain_tbl_size;
        u8 als_mode_active;
        u8 als_gain_mask;
        u8 als_gain_shift;
        struct iio_chan_spec const *channels;
        const int no_channels;
        const struct iio_info *info;
        const struct iio_info *info_no_irq;
};

struct ltr501_data {
        struct i2c_client *client;
        struct mutex lock_als, lock_ps;
        const struct ltr501_chip_info *chip_info;
        u8 als_contr, ps_contr;
        int als_period, ps_period; /* period in micro seconds */
        struct regmap *regmap;
        struct regmap_field *reg_it;
        struct regmap_field *reg_als_intr;
        struct regmap_field *reg_ps_intr;
        struct regmap_field *reg_als_rate;
        struct regmap_field *reg_ps_rate;
        struct regmap_field *reg_als_prst;
        struct regmap_field *reg_ps_prst;
        uint32_t near_level;
};

static const struct ltr501_samp_table ltr501_als_samp_table[] = {
                        {20000000, 50000}, {10000000, 100000},
                        {5000000, 200000}, {2000000, 500000},
                        {1000000, 1000000}, {500000, 2000000},
                        {500000, 2000000}, {500000, 2000000}
};

static const struct ltr501_samp_table ltr501_ps_samp_table[] = {
                        {20000000, 50000}, {14285714, 70000},
                        {10000000, 100000}, {5000000, 200000},
                        {2000000, 500000}, {1000000, 1000000},
                        {500000, 2000000}, {500000, 2000000},
                        {500000, 2000000}
};

static int ltr501_match_samp_freq(const struct ltr501_samp_table *tab,
                                           int len, int val, int val2)
{
        int i, freq;

        freq = val * 1000000 + val2;

        for (i = 0; i < len; i++) {
                if (tab[i].freq_val == freq)
                        return i;
        }

        return -EINVAL;
}

static int ltr501_als_read_samp_freq(const struct ltr501_data *data,
                                     int *val, int *val2)
{
        int ret, i;

        ret = regmap_field_read(data->reg_als_rate, &i);
        if (ret < 0)
                return ret;

        if (i < 0 || i >= ARRAY_SIZE(ltr501_als_samp_table))
                return -EINVAL;

        *val = ltr501_als_samp_table[i].freq_val / 1000000;
        *val2 = ltr501_als_samp_table[i].freq_val % 1000000;

        return IIO_VAL_INT_PLUS_MICRO;
}

static int ltr501_ps_read_samp_freq(const struct ltr501_data *data,
                                    int *val, int *val2)
{
        int ret, i;

        ret = regmap_field_read(data->reg_ps_rate, &i);
        if (ret < 0)
                return ret;

        if (i < 0 || i >= ARRAY_SIZE(ltr501_ps_samp_table))
                return -EINVAL;

        *val = ltr501_ps_samp_table[i].freq_val / 1000000;
        *val2 = ltr501_ps_samp_table[i].freq_val % 1000000;

        return IIO_VAL_INT_PLUS_MICRO;
}

static int ltr501_als_write_samp_freq(struct ltr501_data *data,
                                      int val, int val2)
{
        int i, ret;

        i = ltr501_match_samp_freq(ltr501_als_samp_table,
                                   ARRAY_SIZE(ltr501_als_samp_table),
                                   val, val2);

        if (i < 0)
                return i;

        mutex_lock(&data->lock_als);
        ret = regmap_field_write(data->reg_als_rate, i);
        mutex_unlock(&data->lock_als);

        return ret;
}

static int ltr501_ps_write_samp_freq(struct ltr501_data *data,
                                     int val, int val2)
{
        int i, ret;

        i = ltr501_match_samp_freq(ltr501_ps_samp_table,
                                   ARRAY_SIZE(ltr501_ps_samp_table),
                                   val, val2);

        if (i < 0)
                return i;

        mutex_lock(&data->lock_ps);
        ret = regmap_field_write(data->reg_ps_rate, i);
        mutex_unlock(&data->lock_ps);

        return ret;
}

static int ltr501_als_read_samp_period(const struct ltr501_data *data, int *val)
{
        int ret, i;

        ret = regmap_field_read(data->reg_als_rate, &i);
        if (ret < 0)
                return ret;

        if (i < 0 || i >= ARRAY_SIZE(ltr501_als_samp_table))
                return -EINVAL;

        *val = ltr501_als_samp_table[i].time_val;

        return IIO_VAL_INT;
}

static int ltr501_ps_read_samp_period(const struct ltr501_data *data, int *val)
{
        int ret, i;

        ret = regmap_field_read(data->reg_ps_rate, &i);
        if (ret < 0)
                return ret;

        if (i < 0 || i >= ARRAY_SIZE(ltr501_ps_samp_table))
                return -EINVAL;

        *val = ltr501_ps_samp_table[i].time_val;

        return IIO_VAL_INT;
}

/* IR and visible spectrum coeff's are given in data sheet */
static unsigned long ltr501_calculate_lux(u16 vis_data, u16 ir_data)
{
        unsigned long ratio, lux;

        if (vis_data == 0)
                return 0;

        /* multiply numerator by 100 to avoid handling ratio < 1 */
        ratio = DIV_ROUND_UP(ir_data * 100, ir_data + vis_data);

        if (ratio < 45)
                lux = LTR501_LUX_CONV(1774, vis_data, -1105, ir_data);
        else if (ratio >= 45 && ratio < 64)
                lux = LTR501_LUX_CONV(3772, vis_data, 1336, ir_data);
        else if (ratio >= 64 && ratio < 85)
                lux = LTR501_LUX_CONV(1690, vis_data, 169, ir_data);
        else
                lux = 0;

        return lux / 1000;
}

static int ltr501_drdy(const struct ltr501_data *data, u8 drdy_mask)
{
        int tries = 100;
        int ret, status;

        while (tries--) {
                ret = regmap_read(data->regmap, LTR501_ALS_PS_STATUS, &status);
                if (ret < 0)
                        return ret;
                if ((status & drdy_mask) == drdy_mask)
                        return 0;
                msleep(25);
        }

        dev_err(&data->client->dev, "ltr501_drdy() failed, data not ready\n");
        return -EIO;
}

static int ltr501_set_it_time(struct ltr501_data *data, int it)
{
        int ret, i, index = -1, status;

        for (i = 0; i < ARRAY_SIZE(int_time_mapping); i++) {
                if (int_time_mapping[i] == it) {
                        index = i;
                        break;
                }
        }
        /* Make sure integ time index is valid */
        if (index < 0)
                return -EINVAL;

        ret = regmap_read(data->regmap, LTR501_ALS_CONTR, &status);
        if (ret < 0)
                return ret;

        if (status & LTR501_CONTR_ALS_GAIN_MASK) {
                /*
                 * 200 ms and 400 ms integ time can only be
                 * used in dynamic range 1
                 */
                if (index > 1)
                        return -EINVAL;
        } else
                /* 50 ms integ time can only be used in dynamic range 2 */
                if (index == 1)
                        return -EINVAL;

        return regmap_field_write(data->reg_it, index);
}

/* read int time in micro seconds */
static int ltr501_read_it_time(const struct ltr501_data *data,
                               int *val, int *val2)
{
        int ret, index;

        ret = regmap_field_read(data->reg_it, &index);
        if (ret < 0)
                return ret;

        /* Make sure integ time index is valid */
        if (index < 0 || index >= ARRAY_SIZE(int_time_mapping))
                return -EINVAL;

        *val2 = int_time_mapping[index];
        *val = 0;

        return IIO_VAL_INT_PLUS_MICRO;
}

static int ltr501_read_als(const struct ltr501_data *data, __le16 buf[2])
{
        int ret;

        ret = ltr501_drdy(data, LTR501_STATUS_ALS_RDY);
        if (ret < 0)
                return ret;
        /* always read both ALS channels in given order */
        return regmap_bulk_read(data->regmap, LTR501_ALS_DATA1,
                                buf, 2 * sizeof(__le16));
}

static int ltr501_read_ps(const struct ltr501_data *data)
{
        __le16 status;
        int ret;

        ret = ltr501_drdy(data, LTR501_STATUS_PS_RDY);
        if (ret < 0)
                return ret;

        ret = regmap_bulk_read(data->regmap, LTR501_PS_DATA,
                               &status, sizeof(status));
        if (ret < 0)
                return ret;

        return le16_to_cpu(status);
}

static int ltr501_read_intr_prst(const struct ltr501_data *data,
                                 enum iio_chan_type type,
                                 int *val2)
{
        int ret, samp_period, prst;

        switch (type) {
        case IIO_INTENSITY:
                ret = regmap_field_read(data->reg_als_prst, &prst);
                if (ret < 0)
                        return ret;

                ret = ltr501_als_read_samp_period(data, &samp_period);

                if (ret < 0)
                        return ret;
                *val2 = samp_period * prst;
                return IIO_VAL_INT_PLUS_MICRO;
        case IIO_PROXIMITY:
                ret = regmap_field_read(data->reg_ps_prst, &prst);
                if (ret < 0)
                        return ret;

                ret = ltr501_ps_read_samp_period(data, &samp_period);

                if (ret < 0)
                        return ret;

                *val2 = samp_period * prst;
                return IIO_VAL_INT_PLUS_MICRO;
        default:
                return -EINVAL;
        }

        return -EINVAL;
}

static int ltr501_write_intr_prst(struct ltr501_data *data,
                                  enum iio_chan_type type,
                                  int val, int val2)
{
        int ret, samp_period, new_val;
        unsigned long period;

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

        /* period in microseconds */
        period = ((val * 1000000) + val2);

        switch (type) {
        case IIO_INTENSITY:
                ret = ltr501_als_read_samp_period(data, &samp_period);
                if (ret < 0)
                        return ret;

                /* period should be atleast equal to sampling period */
                if (period < samp_period)
                        return -EINVAL;

                new_val = DIV_ROUND_UP(period, samp_period);
                if (new_val < 0 || new_val > 0x0f)
                        return -EINVAL;

                mutex_lock(&data->lock_als);
                ret = regmap_field_write(data->reg_als_prst, new_val);
                mutex_unlock(&data->lock_als);
                if (ret >= 0)
                        data->als_period = period;

                return ret;
        case IIO_PROXIMITY:
                ret = ltr501_ps_read_samp_period(data, &samp_period);
                if (ret < 0)
                        return ret;

                /* period should be atleast equal to rate */
                if (period < samp_period)
                        return -EINVAL;

                new_val = DIV_ROUND_UP(period, samp_period);
                if (new_val < 0 || new_val > 0x0f)
                        return -EINVAL;

                mutex_lock(&data->lock_ps);
                ret = regmap_field_write(data->reg_ps_prst, new_val);
                mutex_unlock(&data->lock_ps);
                if (ret >= 0)
                        data->ps_period = period;

                return ret;
        default:
                return -EINVAL;
        }

        return -EINVAL;
}

static ssize_t ltr501_read_near_level(struct iio_dev *indio_dev,
                                      uintptr_t priv,
                                      const struct iio_chan_spec *chan,
                                      char *buf)
{
        struct ltr501_data *data = iio_priv(indio_dev);

        return sprintf(buf, "%u\n", data->near_level);
}

static const struct iio_chan_spec_ext_info ltr501_ext_info[] = {
        {
                .name = "nearlevel",
                .shared = IIO_SEPARATE,
                .read = ltr501_read_near_level,
        },
        { }
};

static const struct iio_event_spec ltr501_als_event_spec[] = {
        {
                .type = IIO_EV_TYPE_THRESH,
                .dir = IIO_EV_DIR_RISING,
                .mask_separate = BIT(IIO_EV_INFO_VALUE),
        }, {
                .type = IIO_EV_TYPE_THRESH,
                .dir = IIO_EV_DIR_FALLING,
                .mask_separate = BIT(IIO_EV_INFO_VALUE),
        }, {
                .type = IIO_EV_TYPE_THRESH,
                .dir = IIO_EV_DIR_EITHER,
                .mask_separate = BIT(IIO_EV_INFO_ENABLE) |
                                 BIT(IIO_EV_INFO_PERIOD),
        },

};

static const struct iio_event_spec ltr501_pxs_event_spec[] = {
        {
                .type = IIO_EV_TYPE_THRESH,
                .dir = IIO_EV_DIR_RISING,
                .mask_separate = BIT(IIO_EV_INFO_VALUE),
        }, {
                .type = IIO_EV_TYPE_THRESH,
                .dir = IIO_EV_DIR_FALLING,
                .mask_separate = BIT(IIO_EV_INFO_VALUE),
        }, {
                .type = IIO_EV_TYPE_THRESH,
                .dir = IIO_EV_DIR_EITHER,
                .mask_separate = BIT(IIO_EV_INFO_ENABLE) |
                                 BIT(IIO_EV_INFO_PERIOD),
        },
};

#define LTR501_INTENSITY_CHANNEL(_idx, _addr, _mod, _shared, \
                                 _evspec, _evsize) { \
        .type = IIO_INTENSITY, \
        .modified = 1, \
        .address = (_addr), \
        .channel2 = (_mod), \
        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
        .info_mask_shared_by_type = (_shared), \
        .scan_index = (_idx), \
        .scan_type = { \
                .sign = 'u', \
                .realbits = 16, \
                .storagebits = 16, \
                .endianness = IIO_CPU, \
        }, \
        .event_spec = _evspec,\
        .num_event_specs = _evsize,\
}

#define LTR501_LIGHT_CHANNEL() { \
        .type = IIO_LIGHT, \
        .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
        .scan_index = -1, \
}

static const struct iio_chan_spec ltr501_channels[] = {
        LTR501_LIGHT_CHANNEL(),
        LTR501_INTENSITY_CHANNEL(0, LTR501_ALS_DATA0, IIO_MOD_LIGHT_BOTH, 0,
                                 ltr501_als_event_spec,
                                 ARRAY_SIZE(ltr501_als_event_spec)),
        LTR501_INTENSITY_CHANNEL(1, LTR501_ALS_DATA1, IIO_MOD_LIGHT_IR,
                                 BIT(IIO_CHAN_INFO_SCALE) |
                                 BIT(IIO_CHAN_INFO_INT_TIME) |
                                 BIT(IIO_CHAN_INFO_SAMP_FREQ),
                                 NULL, 0),
        {
                .type = IIO_PROXIMITY,
                .address = LTR501_PS_DATA,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
                        BIT(IIO_CHAN_INFO_SCALE),
                .scan_index = 2,
                .scan_type = {
                        .sign = 'u',
                        .realbits = 11,
                        .storagebits = 16,
                        .endianness = IIO_CPU,
                },
                .event_spec = ltr501_pxs_event_spec,
                .num_event_specs = ARRAY_SIZE(ltr501_pxs_event_spec),
                .ext_info = ltr501_ext_info,
        },
        IIO_CHAN_SOFT_TIMESTAMP(3),
};

static const struct iio_chan_spec ltr301_channels[] = {
        LTR501_LIGHT_CHANNEL(),
        LTR501_INTENSITY_CHANNEL(0, LTR501_ALS_DATA0, IIO_MOD_LIGHT_BOTH, 0,
                                 ltr501_als_event_spec,
                                 ARRAY_SIZE(ltr501_als_event_spec)),
        LTR501_INTENSITY_CHANNEL(1, LTR501_ALS_DATA1, IIO_MOD_LIGHT_IR,
                                 BIT(IIO_CHAN_INFO_SCALE) |
                                 BIT(IIO_CHAN_INFO_INT_TIME) |
                                 BIT(IIO_CHAN_INFO_SAMP_FREQ),
                                 NULL, 0),
        IIO_CHAN_SOFT_TIMESTAMP(2),
};

static int ltr501_read_info_raw(struct ltr501_data *data,
                                struct iio_chan_spec const *chan,
                                int *val)
{
        __le16 buf[2];
        int ret;

        switch (chan->type) {
        case IIO_INTENSITY:
                mutex_lock(&data->lock_als);
                ret = ltr501_read_als(data, buf);
                mutex_unlock(&data->lock_als);
                if (ret < 0)
                        return ret;
                *val = le16_to_cpu(chan->address == LTR501_ALS_DATA1 ?
                                   buf[0] : buf[1]);
                return IIO_VAL_INT;
        case IIO_PROXIMITY:
                mutex_lock(&data->lock_ps);
                ret = ltr501_read_ps(data);
                mutex_unlock(&data->lock_ps);
                if (ret < 0)
                        return ret;
                *val = ret & LTR501_PS_DATA_MASK;
                return IIO_VAL_INT;
        default:
                return -EINVAL;
        }
}

static int ltr501_read_raw(struct iio_dev *indio_dev,
                           struct iio_chan_spec const *chan,
                           int *val, int *val2, long mask)
{
        struct ltr501_data *data = iio_priv(indio_dev);
        __le16 buf[2];
        int ret, i;

        switch (mask) {
        case IIO_CHAN_INFO_PROCESSED:
                switch (chan->type) {
                case IIO_LIGHT:
                        if (!iio_device_claim_direct(indio_dev))
                                return -EBUSY;

                        mutex_lock(&data->lock_als);
                        ret = ltr501_read_als(data, buf);
                        mutex_unlock(&data->lock_als);
                        iio_device_release_direct(indio_dev);
                        if (ret < 0)
                                return ret;
                        *val = ltr501_calculate_lux(le16_to_cpu(buf[1]),
                                                    le16_to_cpu(buf[0]));
                        return IIO_VAL_INT;
                default:
                        return -EINVAL;
                }
        case IIO_CHAN_INFO_RAW:
                if (!iio_device_claim_direct(indio_dev))
                        return -EBUSY;

                ret = ltr501_read_info_raw(data, chan, val);

                iio_device_release_direct(indio_dev);
                return ret;

        case IIO_CHAN_INFO_SCALE:
                switch (chan->type) {
                case IIO_INTENSITY:
                        i = (data->als_contr & data->chip_info->als_gain_mask)
                             >> data->chip_info->als_gain_shift;
                        *val = data->chip_info->als_gain[i].scale;
                        *val2 = data->chip_info->als_gain[i].uscale;
                        return IIO_VAL_INT_PLUS_MICRO;
                case IIO_PROXIMITY:
                        i = (data->ps_contr & LTR501_CONTR_PS_GAIN_MASK) >>
                                LTR501_CONTR_PS_GAIN_SHIFT;
                        *val = data->chip_info->ps_gain[i].scale;
                        *val2 = data->chip_info->ps_gain[i].uscale;
                        return IIO_VAL_INT_PLUS_MICRO;
                default:
                        return -EINVAL;
                }
        case IIO_CHAN_INFO_INT_TIME:
                switch (chan->type) {
                case IIO_INTENSITY:
                        return ltr501_read_it_time(data, val, val2);
                default:
                        return -EINVAL;
                }
        case IIO_CHAN_INFO_SAMP_FREQ:
                switch (chan->type) {
                case IIO_INTENSITY:
                        return ltr501_als_read_samp_freq(data, val, val2);
                case IIO_PROXIMITY:
                        return ltr501_ps_read_samp_freq(data, val, val2);
                default:
                        return -EINVAL;
                }
        }
        return -EINVAL;
}

static int ltr501_get_gain_index(const struct ltr501_gain *gain, int size,
                                 int val, int val2)
{
        int i;

        for (i = 0; i < size; i++)
                if (val == gain[i].scale && val2 == gain[i].uscale)
                        return i;

        return -1;
}

static int __ltr501_write_raw(struct iio_dev *indio_dev,
                              struct iio_chan_spec const *chan,
                              int val, int val2, long mask)
{
        struct ltr501_data *data = iio_priv(indio_dev);
        int i, ret, freq_val, freq_val2;
        const struct ltr501_chip_info *info = data->chip_info;

        switch (mask) {
        case IIO_CHAN_INFO_SCALE:
                switch (chan->type) {
                case IIO_INTENSITY:
                        i = ltr501_get_gain_index(info->als_gain,
                                                  info->als_gain_tbl_size,
                                                  val, val2);
                        if (i < 0)
                                return -EINVAL;

                        data->als_contr &= ~info->als_gain_mask;
                        data->als_contr |= i << info->als_gain_shift;

                        return regmap_write(data->regmap, LTR501_ALS_CONTR,
                                            data->als_contr);
                case IIO_PROXIMITY:
                        i = ltr501_get_gain_index(info->ps_gain,
                                                  info->ps_gain_tbl_size,
                                                  val, val2);
                        if (i < 0)
                                return -EINVAL;

                        data->ps_contr &= ~LTR501_CONTR_PS_GAIN_MASK;
                        data->ps_contr |= i << LTR501_CONTR_PS_GAIN_SHIFT;

                        return regmap_write(data->regmap, LTR501_PS_CONTR,
                                            data->ps_contr);
                default:
                        return -EINVAL;
                }

        case IIO_CHAN_INFO_INT_TIME:
                switch (chan->type) {
                case IIO_INTENSITY:
                        if (val != 0)
                                return -EINVAL;

                        mutex_lock(&data->lock_als);
                        ret = ltr501_set_it_time(data, val2);
                        mutex_unlock(&data->lock_als);
                        return ret;
                default:
                        return -EINVAL;
                }

        case IIO_CHAN_INFO_SAMP_FREQ:
                switch (chan->type) {
                case IIO_INTENSITY:
                        ret = ltr501_als_read_samp_freq(data, &freq_val,
                                                        &freq_val2);
                        if (ret < 0)
                                return ret;

                        ret = ltr501_als_write_samp_freq(data, val, val2);
                        if (ret < 0)
                                return ret;

                        /* update persistence count when changing frequency */
                        ret = ltr501_write_intr_prst(data, chan->type,
                                                     0, data->als_period);

                        if (ret < 0)
                                /* Do not ovewrite error */
                                ltr501_als_write_samp_freq(data, freq_val,
                                                           freq_val2);
                        return ret;
                case IIO_PROXIMITY:
                        ret = ltr501_ps_read_samp_freq(data, &freq_val,
                                                       &freq_val2);
                        if (ret < 0)
                                return ret;

                        ret = ltr501_ps_write_samp_freq(data, val, val2);
                        if (ret < 0)
                                return ret;

                        /* update persistence count when changing frequency */
                        ret = ltr501_write_intr_prst(data, chan->type,
                                                     0, data->ps_period);

                        if (ret < 0)
                                /* Do not overwrite error */
                                ltr501_ps_write_samp_freq(data, freq_val,
                                                          freq_val2);
                        return ret;
                default:
                        return -EINVAL;
                }
        default:
                return -EINVAL;
        }
}

static int ltr501_write_raw(struct iio_dev *indio_dev,
                            struct iio_chan_spec const *chan,
                            int val, int val2, long mask)
{
        int ret;

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

        ret = __ltr501_write_raw(indio_dev, chan, val, val2, mask);

        iio_device_release_direct(indio_dev);

        return ret;
}

static int ltr501_read_thresh(const 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)
{
        const struct ltr501_data *data = iio_priv(indio_dev);
        int ret, thresh_data;

        switch (chan->type) {
        case IIO_INTENSITY:
                switch (dir) {
                case IIO_EV_DIR_RISING:
                        ret = regmap_bulk_read(data->regmap,
                                               LTR501_ALS_THRESH_UP,
                                               &thresh_data, 2);
                        if (ret < 0)
                                return ret;
                        *val = thresh_data & LTR501_ALS_THRESH_MASK;
                        return IIO_VAL_INT;
                case IIO_EV_DIR_FALLING:
                        ret = regmap_bulk_read(data->regmap,
                                               LTR501_ALS_THRESH_LOW,
                                               &thresh_data, 2);
                        if (ret < 0)
                                return ret;
                        *val = thresh_data & LTR501_ALS_THRESH_MASK;
                        return IIO_VAL_INT;
                default:
                        return -EINVAL;
                }
        case IIO_PROXIMITY:
                switch (dir) {
                case IIO_EV_DIR_RISING:
                        ret = regmap_bulk_read(data->regmap,
                                               LTR501_PS_THRESH_UP,
                                               &thresh_data, 2);
                        if (ret < 0)
                                return ret;
                        *val = thresh_data & LTR501_PS_THRESH_MASK;
                        return IIO_VAL_INT;
                case IIO_EV_DIR_FALLING:
                        ret = regmap_bulk_read(data->regmap,
                                               LTR501_PS_THRESH_LOW,
                                               &thresh_data, 2);
                        if (ret < 0)
                                return ret;
                        *val = thresh_data & LTR501_PS_THRESH_MASK;
                        return IIO_VAL_INT;
                default:
                        return -EINVAL;
                }
        default:
                return -EINVAL;
        }

        return -EINVAL;
}

static int ltr501_write_thresh(struct iio_dev *indio_dev,
                               const struct iio_chan_spec *chan,
                               enum iio_event_type type,
                               enum iio_event_direction dir,
                               enum iio_event_info info,
                               int val, int val2)
{
        struct ltr501_data *data = iio_priv(indio_dev);
        int ret;

        if (val < 0)
                return -EINVAL;

        switch (chan->type) {
        case IIO_INTENSITY:
                if (val > LTR501_ALS_THRESH_MASK)
                        return -EINVAL;
                switch (dir) {
                case IIO_EV_DIR_RISING:
                        mutex_lock(&data->lock_als);
                        ret = regmap_bulk_write(data->regmap,
                                                LTR501_ALS_THRESH_UP,
                                                &val, 2);
                        mutex_unlock(&data->lock_als);
                        return ret;
                case IIO_EV_DIR_FALLING:
                        mutex_lock(&data->lock_als);
                        ret = regmap_bulk_write(data->regmap,
                                                LTR501_ALS_THRESH_LOW,
                                                &val, 2);
                        mutex_unlock(&data->lock_als);
                        return ret;
                default:
                        return -EINVAL;
                }
        case IIO_PROXIMITY:
                if (val > LTR501_PS_THRESH_MASK)
                        return -EINVAL;
                switch (dir) {
                case IIO_EV_DIR_RISING:
                        mutex_lock(&data->lock_ps);
                        ret = regmap_bulk_write(data->regmap,
                                                LTR501_PS_THRESH_UP,
                                                &val, 2);
                        mutex_unlock(&data->lock_ps);
                        return ret;
                case IIO_EV_DIR_FALLING:
                        mutex_lock(&data->lock_ps);
                        ret = regmap_bulk_write(data->regmap,
                                                LTR501_PS_THRESH_LOW,
                                                &val, 2);
                        mutex_unlock(&data->lock_ps);
                        return ret;
                default:
                        return -EINVAL;
                }
        default:
                return -EINVAL;
        }

        return -EINVAL;
}

static int ltr501_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)
{
        int ret;

        switch (info) {
        case IIO_EV_INFO_VALUE:
                return ltr501_read_thresh(indio_dev, chan, type, dir,
                                          info, val, val2);
        case IIO_EV_INFO_PERIOD:
                ret = ltr501_read_intr_prst(iio_priv(indio_dev),
                                            chan->type, val2);
                *val = *val2 / 1000000;
                *val2 = *val2 % 1000000;
                return ret;
        default:
                return -EINVAL;
        }

        return -EINVAL;
}

static int ltr501_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)
{
        switch (info) {
        case IIO_EV_INFO_VALUE:
                if (val2 != 0)
                        return -EINVAL;
                return ltr501_write_thresh(indio_dev, chan, type, dir,
                                           info, val, val2);
        case IIO_EV_INFO_PERIOD:
                return ltr501_write_intr_prst(iio_priv(indio_dev), chan->type,
                                              val, val2);
        default:
                return -EINVAL;
        }

        return -EINVAL;
}

static int ltr501_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 ltr501_data *data = iio_priv(indio_dev);
        int ret, status;

        switch (chan->type) {
        case IIO_INTENSITY:
                ret = regmap_field_read(data->reg_als_intr, &status);
                if (ret < 0)
                        return ret;
                return status;
        case IIO_PROXIMITY:
                ret = regmap_field_read(data->reg_ps_intr, &status);
                if (ret < 0)
                        return ret;
                return status;
        default:
                return -EINVAL;
        }

        return -EINVAL;
}

static int ltr501_write_event_config(struct iio_dev *indio_dev,
                                     const struct iio_chan_spec *chan,
                                     enum iio_event_type type,
                                     enum iio_event_direction dir, bool state)
{
        struct ltr501_data *data = iio_priv(indio_dev);
        int ret;

        switch (chan->type) {
        case IIO_INTENSITY:
                mutex_lock(&data->lock_als);
                ret = regmap_field_write(data->reg_als_intr, state);
                mutex_unlock(&data->lock_als);
                return ret;
        case IIO_PROXIMITY:
                mutex_lock(&data->lock_ps);
                ret = regmap_field_write(data->reg_ps_intr, state);
                mutex_unlock(&data->lock_ps);
                return ret;
        default:
                return -EINVAL;
        }

        return -EINVAL;
}

static ssize_t ltr501_show_proximity_scale_avail(struct device *dev,
                                                 struct device_attribute *attr,
                                                 char *buf)
{
        struct ltr501_data *data = iio_priv(dev_to_iio_dev(dev));
        const struct ltr501_chip_info *info = data->chip_info;
        ssize_t len = 0;
        int i;

        for (i = 0; i < info->ps_gain_tbl_size; i++) {
                if (info->ps_gain[i].scale == LTR501_RESERVED_GAIN)
                        continue;
                len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06d ",
                                 info->ps_gain[i].scale,
                                 info->ps_gain[i].uscale);
        }

        buf[len - 1] = '\n';

        return len;
}

static ssize_t ltr501_show_intensity_scale_avail(struct device *dev,
                                                 struct device_attribute *attr,
                                                 char *buf)
{
        struct ltr501_data *data = iio_priv(dev_to_iio_dev(dev));
        const struct ltr501_chip_info *info = data->chip_info;
        ssize_t len = 0;
        int i;

        for (i = 0; i < info->als_gain_tbl_size; i++) {
                if (info->als_gain[i].scale == LTR501_RESERVED_GAIN)
                        continue;
                len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06d ",
                                 info->als_gain[i].scale,
                                 info->als_gain[i].uscale);
        }

        buf[len - 1] = '\n';

        return len;
}

static IIO_CONST_ATTR_INT_TIME_AVAIL("0.05 0.1 0.2 0.4");
static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("20 10 5 2 1 0.5");

static IIO_DEVICE_ATTR(in_proximity_scale_available, S_IRUGO,
                       ltr501_show_proximity_scale_avail, NULL, 0);
static IIO_DEVICE_ATTR(in_intensity_scale_available, S_IRUGO,
                       ltr501_show_intensity_scale_avail, NULL, 0);

static struct attribute *ltr501_attributes[] = {
        &iio_dev_attr_in_proximity_scale_available.dev_attr.attr,
        &iio_dev_attr_in_intensity_scale_available.dev_attr.attr,
        &iio_const_attr_integration_time_available.dev_attr.attr,
        &iio_const_attr_sampling_frequency_available.dev_attr.attr,
        NULL
};

static struct attribute *ltr301_attributes[] = {
        &iio_dev_attr_in_intensity_scale_available.dev_attr.attr,
        &iio_const_attr_integration_time_available.dev_attr.attr,
        &iio_const_attr_sampling_frequency_available.dev_attr.attr,
        NULL
};

static const struct attribute_group ltr501_attribute_group = {
        .attrs = ltr501_attributes,
};

static const struct attribute_group ltr301_attribute_group = {
        .attrs = ltr301_attributes,
};

static const struct iio_info ltr501_info_no_irq = {
        .read_raw = ltr501_read_raw,
        .write_raw = ltr501_write_raw,
        .attrs = &ltr501_attribute_group,
};

static const struct iio_info ltr501_info = {
        .read_raw = ltr501_read_raw,
        .write_raw = ltr501_write_raw,
        .attrs = &ltr501_attribute_group,
        .read_event_value       = &ltr501_read_event,
        .write_event_value      = &ltr501_write_event,
        .read_event_config      = &ltr501_read_event_config,
        .write_event_config     = &ltr501_write_event_config,
};

static const struct iio_info ltr301_info_no_irq = {
        .read_raw = ltr501_read_raw,
        .write_raw = ltr501_write_raw,
        .attrs = &ltr301_attribute_group,
};

static const struct iio_info ltr301_info = {
        .read_raw = ltr501_read_raw,
        .write_raw = ltr501_write_raw,
        .attrs = &ltr301_attribute_group,
        .read_event_value       = &ltr501_read_event,
        .write_event_value      = &ltr501_write_event,
        .read_event_config      = &ltr501_read_event_config,
        .write_event_config     = &ltr501_write_event_config,
};

static const struct ltr501_chip_info ltr501_chip_info_tbl[] = {
        [ltr501] = {
                .partid = 0x08,
                .als_gain = ltr501_als_gain_tbl,
                .als_gain_tbl_size = ARRAY_SIZE(ltr501_als_gain_tbl),
                .ps_gain = ltr501_ps_gain_tbl,
                .ps_gain_tbl_size = ARRAY_SIZE(ltr501_ps_gain_tbl),
                .als_mode_active = BIT(0) | BIT(1),
                .als_gain_mask = BIT(3),
                .als_gain_shift = 3,
                .info = &ltr501_info,
                .info_no_irq = &ltr501_info_no_irq,
                .channels = ltr501_channels,
                .no_channels = ARRAY_SIZE(ltr501_channels),
        },
        [ltr559] = {
                .partid = 0x09,
                .als_gain = ltr559_als_gain_tbl,
                .als_gain_tbl_size = ARRAY_SIZE(ltr559_als_gain_tbl),
                .ps_gain = ltr559_ps_gain_tbl,
                .ps_gain_tbl_size = ARRAY_SIZE(ltr559_ps_gain_tbl),
                .als_mode_active = BIT(0),
                .als_gain_mask = BIT(2) | BIT(3) | BIT(4),
                .als_gain_shift = 2,
                .info = &ltr501_info,
                .info_no_irq = &ltr501_info_no_irq,
                .channels = ltr501_channels,
                .no_channels = ARRAY_SIZE(ltr501_channels),
        },
        [ltr301] = {
                .partid = 0x08,
                .als_gain = ltr501_als_gain_tbl,
                .als_gain_tbl_size = ARRAY_SIZE(ltr501_als_gain_tbl),
                .als_mode_active = BIT(0) | BIT(1),
                .als_gain_mask = BIT(3),
                .als_gain_shift = 3,
                .info = &ltr301_info,
                .info_no_irq = &ltr301_info_no_irq,
                .channels = ltr301_channels,
                .no_channels = ARRAY_SIZE(ltr301_channels),
        },
        [ltr303] = {
                .partid = 0x0A,
                .als_gain = ltr559_als_gain_tbl,
                .als_gain_tbl_size = ARRAY_SIZE(ltr559_als_gain_tbl),
                .als_mode_active = BIT(0),
                .als_gain_mask = BIT(2) | BIT(3) | BIT(4),
                .als_gain_shift = 2,
                .info = &ltr301_info,
                .info_no_irq = &ltr301_info_no_irq,
                .channels = ltr301_channels,
                .no_channels = ARRAY_SIZE(ltr301_channels),
        },
};

static int ltr501_write_contr(struct ltr501_data *data, u8 als_val, u8 ps_val)
{
        int ret;

        ret = regmap_write(data->regmap, LTR501_ALS_CONTR, als_val);
        if (ret < 0)
                return ret;

        return regmap_write(data->regmap, LTR501_PS_CONTR, ps_val);
}

static irqreturn_t ltr501_trigger_handler(int irq, void *p)
{
        struct iio_poll_func *pf = p;
        struct iio_dev *indio_dev = pf->indio_dev;
        struct ltr501_data *data = iio_priv(indio_dev);
        struct {
                u16 channels[3];
                aligned_s64 ts;
        } scan = { };
        __le16 als_buf[2];
        u8 mask = 0;
        int j = 0;
        int ret, psdata;

        /* figure out which data needs to be ready */
        if (test_bit(0, indio_dev->active_scan_mask) ||
            test_bit(1, indio_dev->active_scan_mask))
                mask |= LTR501_STATUS_ALS_RDY;
        if (test_bit(2, indio_dev->active_scan_mask))
                mask |= LTR501_STATUS_PS_RDY;

        ret = ltr501_drdy(data, mask);
        if (ret < 0)
                goto done;

        if (mask & LTR501_STATUS_ALS_RDY) {
                ret = regmap_bulk_read(data->regmap, LTR501_ALS_DATA1,
                                       als_buf, sizeof(als_buf));
                if (ret < 0)
                        goto done;
                if (test_bit(0, indio_dev->active_scan_mask))
                        scan.channels[j++] = le16_to_cpu(als_buf[1]);
                if (test_bit(1, indio_dev->active_scan_mask))
                        scan.channels[j++] = le16_to_cpu(als_buf[0]);
        }

        if (mask & LTR501_STATUS_PS_RDY) {
                ret = regmap_bulk_read(data->regmap, LTR501_PS_DATA,
                                       &psdata, 2);
                if (ret < 0)
                        goto done;
                scan.channels[j++] = psdata & LTR501_PS_DATA_MASK;
        }

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

done:
        iio_trigger_notify_done(indio_dev->trig);

        return IRQ_HANDLED;
}

static irqreturn_t ltr501_interrupt_handler(int irq, void *private)
{
        struct iio_dev *indio_dev = private;
        struct ltr501_data *data = iio_priv(indio_dev);
        int ret, status;

        ret = regmap_read(data->regmap, LTR501_ALS_PS_STATUS, &status);
        if (ret < 0) {
                dev_err(&data->client->dev,
                        "irq read int reg failed\n");
                return IRQ_HANDLED;
        }

        if (status & LTR501_STATUS_ALS_INTR)
                iio_push_event(indio_dev,
                               IIO_UNMOD_EVENT_CODE(IIO_INTENSITY, 0,
                                                    IIO_EV_TYPE_THRESH,
                                                    IIO_EV_DIR_EITHER),
                               iio_get_time_ns(indio_dev));

        if (status & LTR501_STATUS_PS_INTR)
                iio_push_event(indio_dev,
                               IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0,
                                                    IIO_EV_TYPE_THRESH,
                                                    IIO_EV_DIR_EITHER),
                               iio_get_time_ns(indio_dev));

        return IRQ_HANDLED;
}

static int ltr501_init(struct ltr501_data *data)
{
        int ret, status;

        ret = regmap_read(data->regmap, LTR501_ALS_CONTR, &status);
        if (ret < 0)
                return ret;

        data->als_contr = status | data->chip_info->als_mode_active;

        ret = regmap_read(data->regmap, LTR501_PS_CONTR, &status);
        if (ret < 0)
                return ret;

        data->ps_contr = status | LTR501_CONTR_ACTIVE;

        ret = ltr501_read_intr_prst(data, IIO_INTENSITY, &data->als_period);
        if (ret < 0)
                return ret;

        ret = ltr501_read_intr_prst(data, IIO_PROXIMITY, &data->ps_period);
        if (ret < 0)
                return ret;

        return ltr501_write_contr(data, data->als_contr, data->ps_contr);
}

static bool ltr501_is_volatile_reg(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case LTR501_ALS_DATA1:
        case LTR501_ALS_DATA1_UPPER:
        case LTR501_ALS_DATA0:
        case LTR501_ALS_DATA0_UPPER:
        case LTR501_ALS_PS_STATUS:
        case LTR501_PS_DATA:
        case LTR501_PS_DATA_UPPER:
                return true;
        default:
                return false;
        }
}

static const struct regmap_config ltr501_regmap_config = {
        .name = "ltr501_regmap",
        .reg_bits = 8,
        .val_bits = 8,
        .max_register = LTR501_MAX_REG,
        .cache_type = REGCACHE_MAPLE,
        .volatile_reg = ltr501_is_volatile_reg,
};

static int ltr501_powerdown(struct ltr501_data *data)
{
        return ltr501_write_contr(data, data->als_contr &
                                  ~data->chip_info->als_mode_active,
                                  data->ps_contr & ~LTR501_CONTR_ACTIVE);
}

static int ltr501_probe(struct i2c_client *client)
{
        const struct i2c_device_id *id = i2c_client_get_device_id(client);
        static const char * const regulator_names[] = { "vdd", "vddio" };
        struct ltr501_data *data;
        struct iio_dev *indio_dev;
        struct regmap *regmap;
        const void *ddata = NULL;
        int partid, chip_idx;
        const char *name;
        int ret;

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

        regmap = devm_regmap_init_i2c(client, &ltr501_regmap_config);
        if (IS_ERR(regmap)) {
                dev_err(&client->dev, "Regmap initialization failed.\n");
                return PTR_ERR(regmap);
        }

        data = iio_priv(indio_dev);
        i2c_set_clientdata(client, indio_dev);
        data->client = client;
        data->regmap = regmap;
        mutex_init(&data->lock_als);
        mutex_init(&data->lock_ps);

        ret = devm_regulator_bulk_get_enable(&client->dev,
                                             ARRAY_SIZE(regulator_names),
                                             regulator_names);
        if (ret)
                return dev_err_probe(&client->dev, ret,
                                     "Failed to get regulators\n");

        data->reg_it = devm_regmap_field_alloc(&client->dev, regmap,
                                               reg_field_it);
        if (IS_ERR(data->reg_it)) {
                dev_err(&client->dev, "Integ time reg field init failed.\n");
                return PTR_ERR(data->reg_it);
        }

        data->reg_als_intr = devm_regmap_field_alloc(&client->dev, regmap,
                                                     reg_field_als_intr);
        if (IS_ERR(data->reg_als_intr)) {
                dev_err(&client->dev, "ALS intr mode reg field init failed\n");
                return PTR_ERR(data->reg_als_intr);
        }

        data->reg_ps_intr = devm_regmap_field_alloc(&client->dev, regmap,
                                                    reg_field_ps_intr);
        if (IS_ERR(data->reg_ps_intr)) {
                dev_err(&client->dev, "PS intr mode reg field init failed.\n");
                return PTR_ERR(data->reg_ps_intr);
        }

        data->reg_als_rate = devm_regmap_field_alloc(&client->dev, regmap,
                                                     reg_field_als_rate);
        if (IS_ERR(data->reg_als_rate)) {
                dev_err(&client->dev, "ALS samp rate field init failed.\n");
                return PTR_ERR(data->reg_als_rate);
        }

        data->reg_ps_rate = devm_regmap_field_alloc(&client->dev, regmap,
                                                    reg_field_ps_rate);
        if (IS_ERR(data->reg_ps_rate)) {
                dev_err(&client->dev, "PS samp rate field init failed.\n");
                return PTR_ERR(data->reg_ps_rate);
        }

        data->reg_als_prst = devm_regmap_field_alloc(&client->dev, regmap,
                                                     reg_field_als_prst);
        if (IS_ERR(data->reg_als_prst)) {
                dev_err(&client->dev, "ALS prst reg field init failed\n");
                return PTR_ERR(data->reg_als_prst);
        }

        data->reg_ps_prst = devm_regmap_field_alloc(&client->dev, regmap,
                                                    reg_field_ps_prst);
        if (IS_ERR(data->reg_ps_prst)) {
                dev_err(&client->dev, "PS prst reg field init failed.\n");
                return PTR_ERR(data->reg_ps_prst);
        }

        ret = regmap_read(data->regmap, LTR501_PART_ID, &partid);
        if (ret < 0)
                return ret;

        if (id) {
                name = id->name;
                chip_idx = id->driver_data;
        } else {
                name = iio_get_acpi_device_name_and_data(&client->dev, &ddata);
                chip_idx = (intptr_t)ddata;
        }
        if (!name)
                return -ENODEV;

        data->chip_info = &ltr501_chip_info_tbl[chip_idx];

        if ((partid >> 4) != data->chip_info->partid)
                return -ENODEV;

        if (device_property_read_u32(&client->dev, "proximity-near-level",
                                     &data->near_level))
                data->near_level = 0;

        indio_dev->info = data->chip_info->info;
        indio_dev->channels = data->chip_info->channels;
        indio_dev->num_channels = data->chip_info->no_channels;
        indio_dev->name = name;
        indio_dev->modes = INDIO_DIRECT_MODE;

        ret = ltr501_init(data);
        if (ret < 0)
                return ret;

        if (client->irq > 0) {
                ret = devm_request_threaded_irq(&client->dev, client->irq,
                                                NULL, ltr501_interrupt_handler,
                                                IRQF_TRIGGER_FALLING |
                                                IRQF_ONESHOT,
                                                "ltr501_thresh_event",
                                                indio_dev);
                if (ret) {
                        dev_err(&client->dev, "request irq (%d) failed\n",
                                client->irq);
                        return ret;
                }
        } else {
                indio_dev->info = data->chip_info->info_no_irq;
        }

        ret = iio_triggered_buffer_setup(indio_dev, NULL,
                                         ltr501_trigger_handler, NULL);
        if (ret)
                goto powerdown_on_error;

        ret = iio_device_register(indio_dev);
        if (ret)
                goto error_unreg_buffer;

        return 0;

error_unreg_buffer:
        iio_triggered_buffer_cleanup(indio_dev);
powerdown_on_error:
        ltr501_powerdown(data);
        return ret;
}

static void ltr501_remove(struct i2c_client *client)
{
        struct iio_dev *indio_dev = i2c_get_clientdata(client);

        iio_device_unregister(indio_dev);
        iio_triggered_buffer_cleanup(indio_dev);
        ltr501_powerdown(iio_priv(indio_dev));
}

static int ltr501_suspend(struct device *dev)
{
        struct ltr501_data *data = iio_priv(i2c_get_clientdata(
                                            to_i2c_client(dev)));
        return ltr501_powerdown(data);
}

static int ltr501_resume(struct device *dev)
{
        struct ltr501_data *data = iio_priv(i2c_get_clientdata(
                                            to_i2c_client(dev)));

        return ltr501_write_contr(data, data->als_contr,
                data->ps_contr);
}

static DEFINE_SIMPLE_DEV_PM_OPS(ltr501_pm_ops, ltr501_suspend, ltr501_resume);

static const struct acpi_device_id ltr_acpi_match[] = {
        { "LTER0301", ltr301 },
        /* https://www.catalog.update.microsoft.com/Search.aspx?q=lter0303 */
        { "LTER0303", ltr303 },
        { }
};
MODULE_DEVICE_TABLE(acpi, ltr_acpi_match);

static const struct i2c_device_id ltr501_id[] = {
        { "ltr501", ltr501 },
        { "ltr559", ltr559 },
        { "ltr301", ltr301 },
        { "ltr303", ltr303 },
        { }
};
MODULE_DEVICE_TABLE(i2c, ltr501_id);

static const struct of_device_id ltr501_of_match[] = {
        { .compatible = "liteon,ltr501", },
        { .compatible = "liteon,ltr559", },
        { .compatible = "liteon,ltr301", },
        { .compatible = "liteon,ltr303", },
        { }
};
MODULE_DEVICE_TABLE(of, ltr501_of_match);

static struct i2c_driver ltr501_driver = {
        .driver = {
                .name   = "ltr501",
                .of_match_table = ltr501_of_match,
                .pm     = pm_sleep_ptr(&ltr501_pm_ops),
                .acpi_match_table = ltr_acpi_match,
        },
        .probe = ltr501_probe,
        .remove = ltr501_remove,
        .id_table = ltr501_id,
};

module_i2c_driver(ltr501_driver);

MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
MODULE_DESCRIPTION("Lite-On LTR501 ambient light and proximity sensor driver");
MODULE_LICENSE("GPL");