root/drivers/iio/proximity/sx9310.c
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright 2018 Google LLC.
 *
 * Driver for Semtech's SX9310/SX9311 capacitive proximity/button solution.
 * Based on SX9500 driver and Semtech driver using the input framework
 * <https://my.syncplicity.com/share/teouwsim8niiaud/
 *          linux-driver-SX9310_NoSmartHSensing>.
 * Reworked in April 2019 by Evan Green <evgreen@chromium.org>
 * and in January 2020 by Daniel Campello <campello@chromium.org>.
 */

#include <linux/bitfield.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/log2.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/pm.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/iio/iio.h>

#include "sx_common.h"

/* Register definitions. */
#define SX9310_REG_IRQ_SRC                              SX_COMMON_REG_IRQ_SRC
#define SX9310_REG_STAT0                                0x01
#define SX9310_REG_STAT1                                0x02
#define SX9310_REG_STAT1_COMPSTAT_MASK                  GENMASK(3, 0)
#define SX9310_REG_IRQ_MSK                              0x03
#define   SX9310_CONVDONE_IRQ                           BIT(3)
#define   SX9310_FAR_IRQ                                BIT(5)
#define   SX9310_CLOSE_IRQ                              BIT(6)
#define SX9310_REG_IRQ_FUNC                             0x04

#define SX9310_REG_PROX_CTRL0                           0x10
#define   SX9310_REG_PROX_CTRL0_SENSOREN_MASK           GENMASK(3, 0)
#define   SX9310_REG_PROX_CTRL0_SCANPERIOD_MASK         GENMASK(7, 4)
#define   SX9310_REG_PROX_CTRL0_SCANPERIOD_15MS         0x01
#define SX9310_REG_PROX_CTRL1                           0x11
#define SX9310_REG_PROX_CTRL2                           0x12
#define   SX9310_REG_PROX_CTRL2_COMBMODE_MASK           GENMASK(7, 6)
#define   SX9310_REG_PROX_CTRL2_COMBMODE_CS0_CS1_CS2_CS3 (0x03 << 6)
#define   SX9310_REG_PROX_CTRL2_COMBMODE_CS1_CS2        (0x02 << 6)
#define   SX9310_REG_PROX_CTRL2_COMBMODE_CS0_CS1        (0x01 << 6)
#define   SX9310_REG_PROX_CTRL2_COMBMODE_CS3            (0x00 << 6)
#define   SX9310_REG_PROX_CTRL2_SHIELDEN_MASK           GENMASK(3, 2)
#define   SX9310_REG_PROX_CTRL2_SHIELDEN_DYNAMIC        (0x01 << 2)
#define   SX9310_REG_PROX_CTRL2_SHIELDEN_GROUND         (0x02 << 2)
#define SX9310_REG_PROX_CTRL3                           0x13
#define   SX9310_REG_PROX_CTRL3_GAIN0_MASK              GENMASK(3, 2)
#define   SX9310_REG_PROX_CTRL3_GAIN0_X8                (0x03 << 2)
#define   SX9310_REG_PROX_CTRL3_GAIN12_MASK             GENMASK(1, 0)
#define   SX9310_REG_PROX_CTRL3_GAIN12_X4               0x02
#define SX9310_REG_PROX_CTRL4                           0x14
#define   SX9310_REG_PROX_CTRL4_RESOLUTION_MASK         GENMASK(2, 0)
#define   SX9310_REG_PROX_CTRL4_RESOLUTION_FINEST       0x07
#define   SX9310_REG_PROX_CTRL4_RESOLUTION_VERY_FINE    0x06
#define   SX9310_REG_PROX_CTRL4_RESOLUTION_FINE         0x05
#define   SX9310_REG_PROX_CTRL4_RESOLUTION_MEDIUM       0x04
#define   SX9310_REG_PROX_CTRL4_RESOLUTION_MEDIUM_COARSE 0x03
#define   SX9310_REG_PROX_CTRL4_RESOLUTION_COARSE       0x02
#define   SX9310_REG_PROX_CTRL4_RESOLUTION_VERY_COARSE  0x01
#define   SX9310_REG_PROX_CTRL4_RESOLUTION_COARSEST     0x00
#define SX9310_REG_PROX_CTRL5                           0x15
#define   SX9310_REG_PROX_CTRL5_RANGE_SMALL             (0x03 << 6)
#define   SX9310_REG_PROX_CTRL5_STARTUPSENS_MASK        GENMASK(3, 2)
#define   SX9310_REG_PROX_CTRL5_STARTUPSENS_CS1         (0x01 << 2)
#define   SX9310_REG_PROX_CTRL5_RAWFILT_MASK            GENMASK(1, 0)
#define   SX9310_REG_PROX_CTRL5_RAWFILT_SHIFT           0
#define   SX9310_REG_PROX_CTRL5_RAWFILT_1P25            0x02
#define SX9310_REG_PROX_CTRL6                           0x16
#define   SX9310_REG_PROX_CTRL6_AVGTHRESH_DEFAULT       0x20
#define SX9310_REG_PROX_CTRL7                           0x17
#define   SX9310_REG_PROX_CTRL7_AVGNEGFILT_2            (0x01 << 3)
#define   SX9310_REG_PROX_CTRL7_AVGPOSFILT_MASK         GENMASK(2, 0)
#define   SX9310_REG_PROX_CTRL7_AVGPOSFILT_SHIFT        0
#define   SX9310_REG_PROX_CTRL7_AVGPOSFILT_512          0x05
#define SX9310_REG_PROX_CTRL8                           0x18
#define   SX9310_REG_PROX_CTRL8_9_PTHRESH_MASK          GENMASK(7, 3)
#define SX9310_REG_PROX_CTRL9                           0x19
#define   SX9310_REG_PROX_CTRL8_9_PTHRESH_28            (0x08 << 3)
#define   SX9310_REG_PROX_CTRL8_9_PTHRESH_96            (0x11 << 3)
#define   SX9310_REG_PROX_CTRL8_9_BODYTHRESH_900        0x03
#define   SX9310_REG_PROX_CTRL8_9_BODYTHRESH_1500       0x05
#define SX9310_REG_PROX_CTRL10                          0x1a
#define   SX9310_REG_PROX_CTRL10_HYST_MASK              GENMASK(5, 4)
#define   SX9310_REG_PROX_CTRL10_HYST_6PCT              (0x01 << 4)
#define   SX9310_REG_PROX_CTRL10_CLOSE_DEBOUNCE_MASK    GENMASK(3, 2)
#define   SX9310_REG_PROX_CTRL10_FAR_DEBOUNCE_MASK      GENMASK(1, 0)
#define   SX9310_REG_PROX_CTRL10_FAR_DEBOUNCE_2         0x01
#define SX9310_REG_PROX_CTRL11                          0x1b
#define SX9310_REG_PROX_CTRL12                          0x1c
#define SX9310_REG_PROX_CTRL13                          0x1d
#define SX9310_REG_PROX_CTRL14                          0x1e
#define SX9310_REG_PROX_CTRL15                          0x1f
#define SX9310_REG_PROX_CTRL16                          0x20
#define SX9310_REG_PROX_CTRL17                          0x21
#define SX9310_REG_PROX_CTRL18                          0x22
#define SX9310_REG_PROX_CTRL19                          0x23
#define SX9310_REG_SAR_CTRL0                            0x2a
#define   SX9310_REG_SAR_CTRL0_SARDEB_4_SAMPLES         (0x02 << 5)
#define   SX9310_REG_SAR_CTRL0_SARHYST_8                (0x02 << 3)
#define SX9310_REG_SAR_CTRL1                            0x2b
/* Each increment of the slope register is 0.0078125. */
#define   SX9310_REG_SAR_CTRL1_SLOPE(_hnslope)          (_hnslope / 78125)
#define SX9310_REG_SAR_CTRL2                            0x2c
#define   SX9310_REG_SAR_CTRL2_SAROFFSET_DEFAULT        0x3c

#define SX9310_REG_SENSOR_SEL                           0x30
#define SX9310_REG_USE_MSB                              0x31
#define SX9310_REG_USE_LSB                              0x32
#define SX9310_REG_AVG_MSB                              0x33
#define SX9310_REG_AVG_LSB                              0x34
#define SX9310_REG_DIFF_MSB                             0x35
#define SX9310_REG_DIFF_LSB                             0x36
#define SX9310_REG_OFFSET_MSB                           0x37
#define SX9310_REG_OFFSET_LSB                           0x38
#define SX9310_REG_SAR_MSB                              0x39
#define SX9310_REG_SAR_LSB                              0x3a
#define SX9310_REG_I2C_ADDR                             0x40
#define SX9310_REG_PAUSE                                0x41
#define SX9310_REG_WHOAMI                               0x42
#define   SX9310_WHOAMI_VALUE                           0x01
#define   SX9311_WHOAMI_VALUE                           0x02
#define SX9310_REG_RESET                                0x7f


/* 4 hardware channels, as defined in STAT0: COMB, CS2, CS1 and CS0. */
#define SX9310_NUM_CHANNELS                             4
static_assert(SX9310_NUM_CHANNELS <= SX_COMMON_MAX_NUM_CHANNELS);

#define SX9310_NAMED_CHANNEL(idx, name)                          \
{                                                                \
        .type = IIO_PROXIMITY,                                   \
        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |           \
                              BIT(IIO_CHAN_INFO_HARDWAREGAIN),   \
        .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
        .info_mask_separate_available =                          \
                BIT(IIO_CHAN_INFO_HARDWAREGAIN),                 \
        .info_mask_shared_by_all_available =                     \
                BIT(IIO_CHAN_INFO_SAMP_FREQ),                    \
        .indexed = 1,                                            \
        .channel = idx,                                          \
        .extend_name = name,                                     \
        .address = SX9310_REG_DIFF_MSB,                          \
        .event_spec = sx_common_events,                          \
        .num_event_specs = ARRAY_SIZE(sx_common_events),         \
        .scan_index = idx,                                       \
        .scan_type = {                                           \
                .sign = 's',                                     \
                .realbits = 12,                                  \
                .storagebits = 16,                               \
                .endianness = IIO_BE,                            \
        },                                                       \
}
#define SX9310_CHANNEL(idx) SX9310_NAMED_CHANNEL(idx, NULL)

struct sx931x_info {
        const char *name;
        unsigned int whoami;
};

static const struct iio_chan_spec sx9310_channels[] = {
        SX9310_CHANNEL(0),                      /* CS0 */
        SX9310_CHANNEL(1),                      /* CS1 */
        SX9310_CHANNEL(2),                      /* CS2 */
        SX9310_NAMED_CHANNEL(3, "comb"),        /* COMB */

        IIO_CHAN_SOFT_TIMESTAMP(4),
};

/*
 * Each entry contains the integer part (val) and the fractional part, in micro
 * seconds. It conforms to the IIO output IIO_VAL_INT_PLUS_MICRO.
 */
static const struct {
        int val;
        int val2;
} sx9310_samp_freq_table[] = {
        { 500, 0 }, /* 0000: Min (no idle time) */
        { 66, 666666 }, /* 0001: 15 ms */
        { 33, 333333 }, /* 0010: 30 ms (Typ.) */
        { 22, 222222 }, /* 0011: 45 ms */
        { 16, 666666 }, /* 0100: 60 ms */
        { 11, 111111 }, /* 0101: 90 ms */
        { 8, 333333 }, /* 0110: 120 ms */
        { 5, 0 }, /* 0111: 200 ms */
        { 2, 500000 }, /* 1000: 400 ms */
        { 1, 666666 }, /* 1001: 600 ms */
        { 1, 250000 }, /* 1010: 800 ms */
        { 1, 0 }, /* 1011: 1 s */
        { 0, 500000 }, /* 1100: 2 s */
        { 0, 333333 }, /* 1101: 3 s */
        { 0, 250000 }, /* 1110: 4 s */
        { 0, 200000 }, /* 1111: 5 s */
};
static const unsigned int sx9310_scan_period_table[] = {
        2,   15,  30,  45,   60,   90,   120,  200,
        400, 600, 800, 1000, 2000, 3000, 4000, 5000,
};

static const struct regmap_range sx9310_writable_reg_ranges[] = {
        regmap_reg_range(SX9310_REG_IRQ_MSK, SX9310_REG_IRQ_FUNC),
        regmap_reg_range(SX9310_REG_PROX_CTRL0, SX9310_REG_PROX_CTRL19),
        regmap_reg_range(SX9310_REG_SAR_CTRL0, SX9310_REG_SAR_CTRL2),
        regmap_reg_range(SX9310_REG_SENSOR_SEL, SX9310_REG_SENSOR_SEL),
        regmap_reg_range(SX9310_REG_OFFSET_MSB, SX9310_REG_OFFSET_LSB),
        regmap_reg_range(SX9310_REG_PAUSE, SX9310_REG_PAUSE),
        regmap_reg_range(SX9310_REG_RESET, SX9310_REG_RESET),
};

static const struct regmap_access_table sx9310_writeable_regs = {
        .yes_ranges = sx9310_writable_reg_ranges,
        .n_yes_ranges = ARRAY_SIZE(sx9310_writable_reg_ranges),
};

static const struct regmap_range sx9310_readable_reg_ranges[] = {
        regmap_reg_range(SX9310_REG_IRQ_SRC, SX9310_REG_IRQ_FUNC),
        regmap_reg_range(SX9310_REG_PROX_CTRL0, SX9310_REG_PROX_CTRL19),
        regmap_reg_range(SX9310_REG_SAR_CTRL0, SX9310_REG_SAR_CTRL2),
        regmap_reg_range(SX9310_REG_SENSOR_SEL, SX9310_REG_SAR_LSB),
        regmap_reg_range(SX9310_REG_I2C_ADDR, SX9310_REG_WHOAMI),
        regmap_reg_range(SX9310_REG_RESET, SX9310_REG_RESET),
};

static const struct regmap_access_table sx9310_readable_regs = {
        .yes_ranges = sx9310_readable_reg_ranges,
        .n_yes_ranges = ARRAY_SIZE(sx9310_readable_reg_ranges),
};

static const struct regmap_range sx9310_volatile_reg_ranges[] = {
        regmap_reg_range(SX9310_REG_IRQ_SRC, SX9310_REG_STAT1),
        regmap_reg_range(SX9310_REG_USE_MSB, SX9310_REG_DIFF_LSB),
        regmap_reg_range(SX9310_REG_SAR_MSB, SX9310_REG_SAR_LSB),
        regmap_reg_range(SX9310_REG_RESET, SX9310_REG_RESET),
};

static const struct regmap_access_table sx9310_volatile_regs = {
        .yes_ranges = sx9310_volatile_reg_ranges,
        .n_yes_ranges = ARRAY_SIZE(sx9310_volatile_reg_ranges),
};

static const struct regmap_config sx9310_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,

        .max_register = SX9310_REG_RESET,
        .cache_type = REGCACHE_RBTREE,

        .wr_table = &sx9310_writeable_regs,
        .rd_table = &sx9310_readable_regs,
        .volatile_table = &sx9310_volatile_regs,
};

static int sx9310_read_prox_data(struct sx_common_data *data,
                                 const struct iio_chan_spec *chan, __be16 *val)
{
        int ret;

        ret = regmap_write(data->regmap, SX9310_REG_SENSOR_SEL, chan->channel);
        if (ret)
                return ret;

        return regmap_bulk_read(data->regmap, chan->address, val, sizeof(*val));
}

/*
 * If we have no interrupt support, we have to wait for a scan period
 * after enabling a channel to get a result.
 */
static int sx9310_wait_for_sample(struct sx_common_data *data)
{
        int ret;
        unsigned int val;

        ret = regmap_read(data->regmap, SX9310_REG_PROX_CTRL0, &val);
        if (ret)
                return ret;

        val = FIELD_GET(SX9310_REG_PROX_CTRL0_SCANPERIOD_MASK, val);

        msleep(sx9310_scan_period_table[val]);

        return 0;
}

static int sx9310_read_gain(struct sx_common_data *data,
                            const struct iio_chan_spec *chan, int *val)
{
        unsigned int regval, gain;
        int ret;

        ret = regmap_read(data->regmap, SX9310_REG_PROX_CTRL3, &regval);
        if (ret)
                return ret;

        switch (chan->channel) {
        case 0:
        case 3:
                gain = FIELD_GET(SX9310_REG_PROX_CTRL3_GAIN0_MASK, regval);
                break;
        case 1:
        case 2:
                gain = FIELD_GET(SX9310_REG_PROX_CTRL3_GAIN12_MASK, regval);
                break;
        default:
                return -EINVAL;
        }

        *val = 1 << gain;

        return IIO_VAL_INT;
}

static int sx9310_read_samp_freq(struct sx_common_data *data, int *val, int *val2)
{
        unsigned int regval;
        int ret;

        ret = regmap_read(data->regmap, SX9310_REG_PROX_CTRL0, &regval);
        if (ret)
                return ret;

        regval = FIELD_GET(SX9310_REG_PROX_CTRL0_SCANPERIOD_MASK, regval);
        *val = sx9310_samp_freq_table[regval].val;
        *val2 = sx9310_samp_freq_table[regval].val2;

        return IIO_VAL_INT_PLUS_MICRO;
}

static int sx9310_read_raw(struct iio_dev *indio_dev,
                           const struct iio_chan_spec *chan, int *val,
                           int *val2, long mask)
{
        struct sx_common_data *data = iio_priv(indio_dev);
        int ret;

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

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

                ret = sx_common_read_proximity(data, chan, val);
                iio_device_release_direct(indio_dev);
                return ret;
        case IIO_CHAN_INFO_HARDWAREGAIN:
                if (!iio_device_claim_direct(indio_dev))
                        return -EBUSY;

                ret = sx9310_read_gain(data, chan, val);
                iio_device_release_direct(indio_dev);
                return ret;
        case IIO_CHAN_INFO_SAMP_FREQ:
                return sx9310_read_samp_freq(data, val, val2);
        default:
                return -EINVAL;
        }
}

static const int sx9310_gain_vals[] = { 1, 2, 4, 8 };

static int sx9310_read_avail(struct iio_dev *indio_dev,
                             struct iio_chan_spec const *chan,
                             const int **vals, int *type, int *length,
                             long mask)
{
        if (chan->type != IIO_PROXIMITY)
                return -EINVAL;

        switch (mask) {
        case IIO_CHAN_INFO_HARDWAREGAIN:
                *type = IIO_VAL_INT;
                *length = ARRAY_SIZE(sx9310_gain_vals);
                *vals = sx9310_gain_vals;
                return IIO_AVAIL_LIST;
        case IIO_CHAN_INFO_SAMP_FREQ:
                *type = IIO_VAL_INT_PLUS_MICRO;
                *length = ARRAY_SIZE(sx9310_samp_freq_table) * 2;
                *vals = (int *)sx9310_samp_freq_table;
                return IIO_AVAIL_LIST;
        default:
                return -EINVAL;
        }
}

static const unsigned int sx9310_pthresh_codes[] = {
        2, 4, 6, 8, 12, 16, 20, 24, 28, 32, 40, 48, 56, 64, 72, 80, 88, 96, 112,
        128, 144, 160, 192, 224, 256, 320, 384, 512, 640, 768, 1024, 1536
};

static int sx9310_get_thresh_reg(unsigned int channel)
{
        switch (channel) {
        case 0:
        case 3:
                return SX9310_REG_PROX_CTRL8;
        case 1:
        case 2:
                return SX9310_REG_PROX_CTRL9;
        default:
                return -EINVAL;
        }
}

static int sx9310_read_thresh(struct sx_common_data *data,
                              const struct iio_chan_spec *chan, int *val)
{
        unsigned int reg;
        unsigned int regval;
        int ret;

        reg = ret = sx9310_get_thresh_reg(chan->channel);
        if (ret < 0)
                return ret;

        ret = regmap_read(data->regmap, reg, &regval);
        if (ret)
                return ret;

        regval = FIELD_GET(SX9310_REG_PROX_CTRL8_9_PTHRESH_MASK, regval);
        if (regval >= ARRAY_SIZE(sx9310_pthresh_codes))
                return -EINVAL;

        *val = sx9310_pthresh_codes[regval];
        return IIO_VAL_INT;
}

static int sx9310_read_hysteresis(struct sx_common_data *data,
                                  const struct iio_chan_spec *chan, int *val)
{
        unsigned int regval, pthresh;
        int ret;

        ret = sx9310_read_thresh(data, chan, &pthresh);
        if (ret < 0)
                return ret;

        ret = regmap_read(data->regmap, SX9310_REG_PROX_CTRL10, &regval);
        if (ret)
                return ret;

        regval = FIELD_GET(SX9310_REG_PROX_CTRL10_HYST_MASK, regval);
        if (!regval)
                regval = 5;

        /* regval is at most 5 */
        *val = pthresh >> (5 - regval);

        return IIO_VAL_INT;
}

static int sx9310_read_far_debounce(struct sx_common_data *data, int *val)
{
        unsigned int regval;
        int ret;

        ret = regmap_read(data->regmap, SX9310_REG_PROX_CTRL10, &regval);
        if (ret)
                return ret;

        regval = FIELD_GET(SX9310_REG_PROX_CTRL10_FAR_DEBOUNCE_MASK, regval);
        if (regval)
                *val = 1 << regval;
        else
                *val = 0;

        return IIO_VAL_INT;
}

static int sx9310_read_close_debounce(struct sx_common_data *data, int *val)
{
        unsigned int regval;
        int ret;

        ret = regmap_read(data->regmap, SX9310_REG_PROX_CTRL10, &regval);
        if (ret)
                return ret;

        regval = FIELD_GET(SX9310_REG_PROX_CTRL10_CLOSE_DEBOUNCE_MASK, regval);
        if (regval)
                *val = 1 << regval;
        else
                *val = 0;

        return IIO_VAL_INT;
}

static int sx9310_read_event_val(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 sx_common_data *data = iio_priv(indio_dev);

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

        switch (info) {
        case IIO_EV_INFO_VALUE:
                return sx9310_read_thresh(data, chan, val);
        case IIO_EV_INFO_PERIOD:
                switch (dir) {
                case IIO_EV_DIR_RISING:
                        return sx9310_read_far_debounce(data, val);
                case IIO_EV_DIR_FALLING:
                        return sx9310_read_close_debounce(data, val);
                default:
                        return -EINVAL;
                }
        case IIO_EV_INFO_HYSTERESIS:
                return sx9310_read_hysteresis(data, chan, val);
        default:
                return -EINVAL;
        }
}

static int sx9310_write_thresh(struct sx_common_data *data,
                               const struct iio_chan_spec *chan, int val)
{
        unsigned int reg;
        unsigned int regval;
        int ret, i;

        reg = ret = sx9310_get_thresh_reg(chan->channel);
        if (ret < 0)
                return ret;

        for (i = 0; i < ARRAY_SIZE(sx9310_pthresh_codes); i++) {
                if (sx9310_pthresh_codes[i] == val) {
                        regval = i;
                        break;
                }
        }

        if (i == ARRAY_SIZE(sx9310_pthresh_codes))
                return -EINVAL;

        regval = FIELD_PREP(SX9310_REG_PROX_CTRL8_9_PTHRESH_MASK, regval);

        guard(mutex)(&data->mutex);
        return regmap_update_bits(data->regmap, reg,
                                  SX9310_REG_PROX_CTRL8_9_PTHRESH_MASK, regval);
}

static int sx9310_write_hysteresis(struct sx_common_data *data,
                                   const struct iio_chan_spec *chan, int _val)
{
        unsigned int hyst, val = _val;
        int ret, pthresh;

        ret = sx9310_read_thresh(data, chan, &pthresh);
        if (ret < 0)
                return ret;

        if (val == 0)
                hyst = 0;
        else if (val == pthresh >> 2)
                hyst = 3;
        else if (val == pthresh >> 3)
                hyst = 2;
        else if (val == pthresh >> 4)
                hyst = 1;
        else
                return -EINVAL;

        hyst = FIELD_PREP(SX9310_REG_PROX_CTRL10_HYST_MASK, hyst);

        guard(mutex)(&data->mutex);
        return regmap_update_bits(data->regmap, SX9310_REG_PROX_CTRL10,
                                  SX9310_REG_PROX_CTRL10_HYST_MASK, hyst);
}

static int sx9310_write_far_debounce(struct sx_common_data *data, int val)
{
        unsigned int regval;

        if (val > 0)
                val = ilog2(val);
        if (!FIELD_FIT(SX9310_REG_PROX_CTRL10_FAR_DEBOUNCE_MASK, val))
                return -EINVAL;

        regval = FIELD_PREP(SX9310_REG_PROX_CTRL10_FAR_DEBOUNCE_MASK, val);

        guard(mutex)(&data->mutex);
        return regmap_update_bits(data->regmap, SX9310_REG_PROX_CTRL10,
                                  SX9310_REG_PROX_CTRL10_FAR_DEBOUNCE_MASK,
                                  regval);
}

static int sx9310_write_close_debounce(struct sx_common_data *data, int val)
{
        unsigned int regval;

        if (val > 0)
                val = ilog2(val);
        if (!FIELD_FIT(SX9310_REG_PROX_CTRL10_CLOSE_DEBOUNCE_MASK, val))
                return -EINVAL;

        regval = FIELD_PREP(SX9310_REG_PROX_CTRL10_CLOSE_DEBOUNCE_MASK, val);

        guard(mutex)(&data->mutex);
        return regmap_update_bits(data->regmap, SX9310_REG_PROX_CTRL10,
                                  SX9310_REG_PROX_CTRL10_CLOSE_DEBOUNCE_MASK,
                                  regval);
}

static int sx9310_write_event_val(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 sx_common_data *data = iio_priv(indio_dev);

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

        switch (info) {
        case IIO_EV_INFO_VALUE:
                return sx9310_write_thresh(data, chan, val);
        case IIO_EV_INFO_PERIOD:
                switch (dir) {
                case IIO_EV_DIR_RISING:
                        return sx9310_write_far_debounce(data, val);
                case IIO_EV_DIR_FALLING:
                        return sx9310_write_close_debounce(data, val);
                default:
                        return -EINVAL;
                }
        case IIO_EV_INFO_HYSTERESIS:
                return sx9310_write_hysteresis(data, chan, val);
        default:
                return -EINVAL;
        }
}

static int sx9310_set_samp_freq(struct sx_common_data *data, int val, int val2)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(sx9310_samp_freq_table); i++)
                if (val == sx9310_samp_freq_table[i].val &&
                    val2 == sx9310_samp_freq_table[i].val2)
                        break;

        if (i == ARRAY_SIZE(sx9310_samp_freq_table))
                return -EINVAL;

        guard(mutex)(&data->mutex);
        return regmap_update_bits(
                data->regmap, SX9310_REG_PROX_CTRL0,
                SX9310_REG_PROX_CTRL0_SCANPERIOD_MASK,
                FIELD_PREP(SX9310_REG_PROX_CTRL0_SCANPERIOD_MASK, i));
}

static int sx9310_write_gain(struct sx_common_data *data,
                             const struct iio_chan_spec *chan, int val)
{
        unsigned int gain, mask;

        gain = ilog2(val);

        switch (chan->channel) {
        case 0:
        case 3:
                mask = SX9310_REG_PROX_CTRL3_GAIN0_MASK;
                gain = FIELD_PREP(SX9310_REG_PROX_CTRL3_GAIN0_MASK, gain);
                break;
        case 1:
        case 2:
                mask = SX9310_REG_PROX_CTRL3_GAIN12_MASK;
                gain = FIELD_PREP(SX9310_REG_PROX_CTRL3_GAIN12_MASK, gain);
                break;
        default:
                return -EINVAL;
        }

        guard(mutex)(&data->mutex);
        return regmap_update_bits(data->regmap, SX9310_REG_PROX_CTRL3, mask,
                                  gain);
}

static int sx9310_write_raw(struct iio_dev *indio_dev,
                            const struct iio_chan_spec *chan, int val, int val2,
                            long mask)
{
        struct sx_common_data *data = iio_priv(indio_dev);

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

        switch (mask) {
        case IIO_CHAN_INFO_SAMP_FREQ:
                return sx9310_set_samp_freq(data, val, val2);
        case IIO_CHAN_INFO_HARDWAREGAIN:
                return sx9310_write_gain(data, chan, val);
        default:
                return -EINVAL;
        }
}

static const struct sx_common_reg_default sx9310_default_regs[] = {
        { SX9310_REG_IRQ_MSK, 0x00 },
        { SX9310_REG_IRQ_FUNC, 0x00 },
        /*
         * The lower 4 bits should not be set as it enable sensors measurements.
         * Turning the detection on before the configuration values are set to
         * good values can cause the device to return erroneous readings.
         */
        { SX9310_REG_PROX_CTRL0, SX9310_REG_PROX_CTRL0_SCANPERIOD_15MS },
        { SX9310_REG_PROX_CTRL1, 0x00 },
        { SX9310_REG_PROX_CTRL2, SX9310_REG_PROX_CTRL2_COMBMODE_CS1_CS2 |
                                 SX9310_REG_PROX_CTRL2_SHIELDEN_DYNAMIC },
        { SX9310_REG_PROX_CTRL3, SX9310_REG_PROX_CTRL3_GAIN0_X8 |
                                 SX9310_REG_PROX_CTRL3_GAIN12_X4 },
        { SX9310_REG_PROX_CTRL4, SX9310_REG_PROX_CTRL4_RESOLUTION_FINEST },
        { SX9310_REG_PROX_CTRL5, SX9310_REG_PROX_CTRL5_RANGE_SMALL |
                                 SX9310_REG_PROX_CTRL5_STARTUPSENS_CS1 |
                                 SX9310_REG_PROX_CTRL5_RAWFILT_1P25 },
        { SX9310_REG_PROX_CTRL6, SX9310_REG_PROX_CTRL6_AVGTHRESH_DEFAULT },
        { SX9310_REG_PROX_CTRL7, SX9310_REG_PROX_CTRL7_AVGNEGFILT_2 |
                                 SX9310_REG_PROX_CTRL7_AVGPOSFILT_512 },
        { SX9310_REG_PROX_CTRL8, SX9310_REG_PROX_CTRL8_9_PTHRESH_96 |
                                 SX9310_REG_PROX_CTRL8_9_BODYTHRESH_1500 },
        { SX9310_REG_PROX_CTRL9, SX9310_REG_PROX_CTRL8_9_PTHRESH_28 |
                                 SX9310_REG_PROX_CTRL8_9_BODYTHRESH_900 },
        { SX9310_REG_PROX_CTRL10, SX9310_REG_PROX_CTRL10_HYST_6PCT |
                                  SX9310_REG_PROX_CTRL10_FAR_DEBOUNCE_2 },
        { SX9310_REG_PROX_CTRL11, 0x00 },
        { SX9310_REG_PROX_CTRL12, 0x00 },
        { SX9310_REG_PROX_CTRL13, 0x00 },
        { SX9310_REG_PROX_CTRL14, 0x00 },
        { SX9310_REG_PROX_CTRL15, 0x00 },
        { SX9310_REG_PROX_CTRL16, 0x00 },
        { SX9310_REG_PROX_CTRL17, 0x00 },
        { SX9310_REG_PROX_CTRL18, 0x00 },
        { SX9310_REG_PROX_CTRL19, 0x00 },
        { SX9310_REG_SAR_CTRL0, SX9310_REG_SAR_CTRL0_SARDEB_4_SAMPLES |
                                SX9310_REG_SAR_CTRL0_SARHYST_8 },
        { SX9310_REG_SAR_CTRL1, SX9310_REG_SAR_CTRL1_SLOPE(10781250) },
        { SX9310_REG_SAR_CTRL2, SX9310_REG_SAR_CTRL2_SAROFFSET_DEFAULT },
};

/* Activate all channels and perform an initial compensation. */
static int sx9310_init_compensation(struct iio_dev *indio_dev)
{
        struct sx_common_data *data = iio_priv(indio_dev);
        int ret;
        unsigned int val;
        unsigned int ctrl0;

        ret = regmap_read(data->regmap, SX9310_REG_PROX_CTRL0, &ctrl0);
        if (ret)
                return ret;

        /* run the compensation phase on all channels */
        ret = regmap_write(data->regmap, SX9310_REG_PROX_CTRL0,
                           ctrl0 | SX9310_REG_PROX_CTRL0_SENSOREN_MASK);
        if (ret)
                return ret;

        ret = regmap_read_poll_timeout(data->regmap, SX9310_REG_STAT1, val,
                                       !(val & SX9310_REG_STAT1_COMPSTAT_MASK),
                                       20000, 2000000);
        if (ret)
                return ret;

        regmap_write(data->regmap, SX9310_REG_PROX_CTRL0, ctrl0);
        return ret;
}

static const struct sx_common_reg_default *
sx9310_get_default_reg(struct device *dev, int idx,
                       struct sx_common_reg_default *reg_def)
{
        u32 combined[SX9310_NUM_CHANNELS];
        u32 start = 0, raw = 0, pos = 0;
        unsigned long comb_mask = 0;
        int ret, i, count;
        const char *res;

        memcpy(reg_def, &sx9310_default_regs[idx], sizeof(*reg_def));
        switch (reg_def->reg) {
        case SX9310_REG_PROX_CTRL2:
                if (device_property_read_bool(dev, "semtech,cs0-ground")) {
                        reg_def->def &= ~SX9310_REG_PROX_CTRL2_SHIELDEN_MASK;
                        reg_def->def |= SX9310_REG_PROX_CTRL2_SHIELDEN_GROUND;
                }

                count = device_property_count_u32(dev, "semtech,combined-sensors");
                if (count < 0 || count > ARRAY_SIZE(combined))
                        break;
                ret = device_property_read_u32_array(dev, "semtech,combined-sensors",
                                combined, count);
                if (ret)
                        break;

                for (i = 0; i < count; i++)
                        comb_mask |= BIT(combined[i]);

                reg_def->def &= ~SX9310_REG_PROX_CTRL2_COMBMODE_MASK;
                if (comb_mask == (BIT(3) | BIT(2) | BIT(1) | BIT(0)))
                        reg_def->def |= SX9310_REG_PROX_CTRL2_COMBMODE_CS0_CS1_CS2_CS3;
                else if (comb_mask == (BIT(1) | BIT(2)))
                        reg_def->def |= SX9310_REG_PROX_CTRL2_COMBMODE_CS1_CS2;
                else if (comb_mask == (BIT(0) | BIT(1)))
                        reg_def->def |= SX9310_REG_PROX_CTRL2_COMBMODE_CS0_CS1;
                else if (comb_mask == BIT(3))
                        reg_def->def |= SX9310_REG_PROX_CTRL2_COMBMODE_CS3;

                break;
        case SX9310_REG_PROX_CTRL4:
                ret = device_property_read_string(dev, "semtech,resolution", &res);
                if (ret)
                        break;

                reg_def->def &= ~SX9310_REG_PROX_CTRL4_RESOLUTION_MASK;
                if (!strcmp(res, "coarsest"))
                        reg_def->def |= SX9310_REG_PROX_CTRL4_RESOLUTION_COARSEST;
                else if (!strcmp(res, "very-coarse"))
                        reg_def->def |= SX9310_REG_PROX_CTRL4_RESOLUTION_VERY_COARSE;
                else if (!strcmp(res, "coarse"))
                        reg_def->def |= SX9310_REG_PROX_CTRL4_RESOLUTION_COARSE;
                else if (!strcmp(res, "medium-coarse"))
                        reg_def->def |= SX9310_REG_PROX_CTRL4_RESOLUTION_MEDIUM_COARSE;
                else if (!strcmp(res, "medium"))
                        reg_def->def |= SX9310_REG_PROX_CTRL4_RESOLUTION_MEDIUM;
                else if (!strcmp(res, "fine"))
                        reg_def->def |= SX9310_REG_PROX_CTRL4_RESOLUTION_FINE;
                else if (!strcmp(res, "very-fine"))
                        reg_def->def |= SX9310_REG_PROX_CTRL4_RESOLUTION_VERY_FINE;
                else if (!strcmp(res, "finest"))
                        reg_def->def |= SX9310_REG_PROX_CTRL4_RESOLUTION_FINEST;

                break;
        case SX9310_REG_PROX_CTRL5:
                ret = device_property_read_u32(dev, "semtech,startup-sensor", &start);
                if (ret) {
                        start = FIELD_GET(SX9310_REG_PROX_CTRL5_STARTUPSENS_MASK,
                                          reg_def->def);
                }

                reg_def->def &= ~SX9310_REG_PROX_CTRL5_STARTUPSENS_MASK;
                reg_def->def |= FIELD_PREP(SX9310_REG_PROX_CTRL5_STARTUPSENS_MASK,
                                           start);

                ret = device_property_read_u32(dev, "semtech,proxraw-strength", &raw);
                if (ret) {
                        raw = FIELD_GET(SX9310_REG_PROX_CTRL5_RAWFILT_MASK,
                                        reg_def->def);
                } else {
                        raw = ilog2(raw);
                }

                reg_def->def &= ~SX9310_REG_PROX_CTRL5_RAWFILT_MASK;
                reg_def->def |= FIELD_PREP(SX9310_REG_PROX_CTRL5_RAWFILT_MASK,
                                           raw);
                break;
        case SX9310_REG_PROX_CTRL7:
                ret = device_property_read_u32(dev, "semtech,avg-pos-strength", &pos);
                if (ret)
                        break;

                /* Powers of 2, except for a gap between 16 and 64 */
                pos = clamp(ilog2(pos), 3, 11) - (pos >= 32 ? 4 : 3);
                reg_def->def &= ~SX9310_REG_PROX_CTRL7_AVGPOSFILT_MASK;
                reg_def->def |= FIELD_PREP(SX9310_REG_PROX_CTRL7_AVGPOSFILT_MASK,
                                           pos);
                break;
        }

        return reg_def;
}

static int sx9310_check_whoami(struct device *dev,
                               struct iio_dev *indio_dev)
{
        struct sx_common_data *data = iio_priv(indio_dev);
        const struct sx931x_info *ddata;
        unsigned int whoami;
        int ret;

        ret = regmap_read(data->regmap, SX9310_REG_WHOAMI, &whoami);
        if (ret)
                return ret;

        ddata = device_get_match_data(dev);
        if (ddata->whoami != whoami)
                return -ENODEV;

        indio_dev->name = ddata->name;

        return 0;
}

static const struct sx_common_chip_info sx9310_chip_info = {
        .reg_stat = SX9310_REG_STAT0,
        .reg_irq_msk = SX9310_REG_IRQ_MSK,
        .reg_enable_chan = SX9310_REG_PROX_CTRL0,
        .reg_reset = SX9310_REG_RESET,

        .mask_enable_chan = SX9310_REG_STAT1_COMPSTAT_MASK,
        .irq_msk_offset = 3,
        .num_channels = SX9310_NUM_CHANNELS,
        .num_default_regs = ARRAY_SIZE(sx9310_default_regs),

        .ops = {
                .read_prox_data = sx9310_read_prox_data,
                .check_whoami = sx9310_check_whoami,
                .init_compensation = sx9310_init_compensation,
                .wait_for_sample = sx9310_wait_for_sample,
                .get_default_reg = sx9310_get_default_reg,
        },

        .iio_channels = sx9310_channels,
        .num_iio_channels = ARRAY_SIZE(sx9310_channels),
        .iio_info =  {
                .read_raw = sx9310_read_raw,
                .read_avail = sx9310_read_avail,
                .read_event_value = sx9310_read_event_val,
                .write_event_value = sx9310_write_event_val,
                .write_raw = sx9310_write_raw,
                .read_event_config = sx_common_read_event_config,
                .write_event_config = sx_common_write_event_config,
        },
};

static int sx9310_probe(struct i2c_client *client)
{
        return sx_common_probe(client, &sx9310_chip_info, &sx9310_regmap_config);
}

static int sx9310_suspend(struct device *dev)
{
        struct sx_common_data *data = iio_priv(dev_get_drvdata(dev));
        u8 ctrl0;
        int ret;

        disable_irq_nosync(data->client->irq);

        guard(mutex)(&data->mutex);
        ret = regmap_read(data->regmap, SX9310_REG_PROX_CTRL0,
                          &data->suspend_ctrl);
        if (ret)
                return ret;

        ctrl0 = data->suspend_ctrl & ~SX9310_REG_PROX_CTRL0_SENSOREN_MASK;
        ret = regmap_write(data->regmap, SX9310_REG_PROX_CTRL0, ctrl0);
        if (ret)
                return ret;

        return regmap_write(data->regmap, SX9310_REG_PAUSE, 0);
}

static int sx9310_resume(struct device *dev)
{
        struct sx_common_data *data = iio_priv(dev_get_drvdata(dev));
        int ret;

        scoped_guard(mutex, &data->mutex) {
                ret = regmap_write(data->regmap, SX9310_REG_PAUSE, 1);
                if (ret)
                        return ret;

                ret = regmap_write(data->regmap, SX9310_REG_PROX_CTRL0,
                                   data->suspend_ctrl);
                if (ret)
                        return ret;
        }

        enable_irq(data->client->irq);
        return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(sx9310_pm_ops, sx9310_suspend, sx9310_resume);

static const struct sx931x_info sx9310_info = {
        .name = "sx9310",
        .whoami = SX9310_WHOAMI_VALUE,
};

static const struct sx931x_info sx9311_info = {
        .name = "sx9311",
        .whoami = SX9311_WHOAMI_VALUE,
};

static const struct acpi_device_id sx9310_acpi_match[] = {
        { "STH9310", (kernel_ulong_t)&sx9310_info },
        { "STH9311", (kernel_ulong_t)&sx9311_info },
        { }
};
MODULE_DEVICE_TABLE(acpi, sx9310_acpi_match);

static const struct of_device_id sx9310_of_match[] = {
        { .compatible = "semtech,sx9310", &sx9310_info },
        { .compatible = "semtech,sx9311", &sx9311_info },
        { }
};
MODULE_DEVICE_TABLE(of, sx9310_of_match);

static const struct i2c_device_id sx9310_id[] = {
        { "sx9310", (kernel_ulong_t)&sx9310_info },
        { "sx9311", (kernel_ulong_t)&sx9311_info },
        { }
};
MODULE_DEVICE_TABLE(i2c, sx9310_id);

static struct i2c_driver sx9310_driver = {
        .driver = {
                .name   = "sx9310",
                .acpi_match_table = sx9310_acpi_match,
                .of_match_table = sx9310_of_match,
                .pm = pm_sleep_ptr(&sx9310_pm_ops),

                /*
                 * Lots of i2c transfers in probe + over 200 ms waiting in
                 * sx9310_init_compensation() mean a slow probe; prefer async
                 * so we don't delay boot if we're builtin to the kernel.
                 */
                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
        },
        .probe          = sx9310_probe,
        .id_table       = sx9310_id,
};
module_i2c_driver(sx9310_driver);

MODULE_AUTHOR("Gwendal Grignou <gwendal@chromium.org>");
MODULE_AUTHOR("Daniel Campello <campello@chromium.org>");
MODULE_DESCRIPTION("Driver for Semtech SX9310/SX9311 proximity sensor");
MODULE_LICENSE("GPL v2");
MODULE_IMPORT_NS("SEMTECH_PROX");