// 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);

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

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		iio_device_claim_direct_scoped(return -EBUSY, indio_dev)
			return sx_common_read_proximity(data, chan, val);
		unreachable();
	case IIO_CHAN_INFO_HARDWAREGAIN:
		iio_device_claim_direct_scoped(return -EBUSY, indio_dev)
			return sx9310_read_gain(data, chan, val);
		unreachable();
	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);