Re: [PATCH v7 3/5] iio: proximity: Add SX9324 support

[Jonathan Cameron <jic23@jic23.retrosnub.co.uk>]

On Fri, 10 Dec 2021 11:23:26 -0800
Gwendal Grignou <gwendal@chromium.org> wrote:

> Semtech SAR sensor SX9324 is an evolution of the SX9310:
> It has 4 phases that can be configure to capture and process data
> from any of 3 CS pins and provide independent detection:
> proximity, table proximity or body proximity.
> 
> Gather antenna data:
> echo sx9324-dev3 > trigger/current_trigger
> echo 1 > scan_elements/in_proximity0_en
> echo 1 > buffer/enable
> od -v -An --endian=big -t d2 -w2 /dev/iio\:device3
> (at 10Hz, the default).
> 
> Trigger events:
> Setting:
> thresh_falling_period: 2 (events)
> thresh_rising_period: 2 (events)
> in_proximity0_thresh_either_value: 300
> in_proximity0_thresh_either_hysteresis: 72
> 
> using iio_event_monitor /dev/iio\:deviceX, approaching my hand to the
> antenna pad, I see:
> ...
> Event: time: 1634763907532035297, type: proximity, channel: 0, evtype:
> thresh, direction: falling
> Event: time: 1634763910138104640, type: proximity, channel: 0, evtype:
> thresh, direction: rising
> ...
> 
> Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Spotted an issue below.  Docs have the ABI as setup, whereas
it's setting in code.

I think I prefer setup, but I'm not that bothered as long as it is
consistent.

Thanks,

Jonathan

> ---
> No changes in v7
> Changes in v6:
> - Drop of_match_ptr and ACPI_PTR protections.
> - Fix unused variable warning.
> 
> Changes in v5:
> - Fix includes with iwyu.
> 
> Changes in v4:
> - Remove SX9324_DRIVER_NAME define
> - Drop comma after sentinel
> - Handle negative values when setting parameters.
> - Simpliy whoami function.
> 
> Changes in v3:
> - Fix constant names
> - Disable IRQ at suspend.
> - Concatenate 2 lines.
> 
> Changes in v2:
> - Use new interface with sx_common.
> - Document phase configuration parameter.
> - Define phase configuration parameter in channel.
> - Only Add needed changes in Kconfig and Makefile.
> - Use read_avail to define available frequencies
> 
>  .../ABI/testing/sysfs-bus-iio-sx9324          |  28 +
>  drivers/iio/proximity/Kconfig                 |  14 +
>  drivers/iio/proximity/Makefile                |   1 +
>  drivers/iio/proximity/sx9324.c                | 912 ++++++++++++++++++
>  4 files changed, 955 insertions(+)
>  create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-sx9324
>  create mode 100644 drivers/iio/proximity/sx9324.c
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-iio-sx9324 b/Documentation/ABI/testing/sysfs-bus-iio-sx9324
> new file mode 100644
> index 00000000000000..632e3321f5a3df
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-iio-sx9324
> @@ -0,0 +1,28 @@
> +What:		/sys/bus/iio/devices/iio:deviceX/in_proximity<id>_setup

Code has this as setting.


> +Date:		November 2021
> +KernelVersion:	5.17
> +Contact:	Gwendal Grignou <gwendal@chromium.org>
> +Description:
> +		SX9324 has 3 inputs, CS0, CS1 and CS2. Hardware layout
> +		defines if the input is
> +		+ not connected (HZ),
> +		+ grounded (GD),
> +		+ connected to an antenna where it can act as a base
> +		  (DS - data shield), or measured input (MI).
> +
> +		The sensor rotates measurement across 4 phases
> +		(PH0, PH1, PH2, PH3), where the inputs are configured
> +		and then measured.
> +
> +		By default,  during the first phase, [PH0], CS0 is measured,
> +		while CS1 and CS2 are used as shields.
> +		`cat in_proximity0_setup` returns "MI,DS,DS".
> +		[PH1], CS1 is measured, CS0 and CS2 are shield:
> +		`cat in_proximity1_setup` returns "DS,MI,DS".
> +		[PH2], CS2 is measured, CS0 and CS1 are shield:
> +		`cat in_proximity1_setup` returns "DS,DS,MI".
> +		[PH3], CS1 and CS2 are measured (combo mode):
> +		`cat in_proximity1_setup` returns "DS,MI,MI".
> +
> +		Note, these are the chip default. Hardware layout will most
> +		likely dictate different output. The entry is read-only.
> diff --git a/drivers/iio/proximity/Kconfig b/drivers/iio/proximity/Kconfig
> index e88fc373c2c903..aaddf97f9b2192 100644
> --- a/drivers/iio/proximity/Kconfig
> +++ b/drivers/iio/proximity/Kconfig
> @@ -129,6 +129,20 @@ config SX9310
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called sx9310.
>  
> +config SX9324
> +	tristate "SX9324 Semtech proximity sensor"
> +	select IIO_BUFFER
> +	select IIO_TRIGGERED_BUFFER
> +	select REGMAP_I2C
> +	select SX_COMMON
> +	depends on I2C
> +	help
> +	  Say Y here to build a driver for Semtech's SX9324
> +	  proximity/button sensor.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called sx9324.
> +
>  config SX9500
>  	tristate "SX9500 Semtech proximity sensor"
>  	select IIO_BUFFER
> diff --git a/drivers/iio/proximity/Makefile b/drivers/iio/proximity/Makefile
> index 2577fbce4144e5..cffe962b352718 100644
> --- a/drivers/iio/proximity/Makefile
> +++ b/drivers/iio/proximity/Makefile
> @@ -14,6 +14,7 @@ obj-$(CONFIG_RFD77402)		+= rfd77402.o
>  obj-$(CONFIG_SRF04)		+= srf04.o
>  obj-$(CONFIG_SRF08)		+= srf08.o
>  obj-$(CONFIG_SX9310)		+= sx9310.o
> +obj-$(CONFIG_SX9324)		+= sx9324.o
>  obj-$(CONFIG_SX_COMMON) 	+= sx_common.o
>  obj-$(CONFIG_SX9500)		+= sx9500.o
>  obj-$(CONFIG_VCNL3020)		+= vcnl3020.o
> diff --git a/drivers/iio/proximity/sx9324.c b/drivers/iio/proximity/sx9324.c
> new file mode 100644
> index 00000000000000..ed7ac30e1915d5
> --- /dev/null
> +++ b/drivers/iio/proximity/sx9324.c
> @@ -0,0 +1,912 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright 2021 Google LLC.
> + *
> + * Driver for Semtech's SX9324 capacitive proximity/button solution.
> + * Based on SX9324 driver and copy of datasheet at:
> + * https://edit.wpgdadawant.com/uploads/news_file/program/2019/30184/tech_files/program_30184_suggest_other_file.pdf
> + */
> +
> +#include <linux/acpi.h>
> +#include <linux/bits.h>
> +#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 SX9324_REG_IRQ_SRC		SX_COMMON_REG_IRQ_SRC
> +#define SX9324_REG_STAT0		0x01
> +#define SX9324_REG_STAT1		0x02
> +#define SX9324_REG_STAT2		0x03
> +#define SX9324_REG_STAT2_COMPSTAT_MASK	GENMASK(3, 0)
> +#define SX9324_REG_STAT3		0x04
> +#define SX9324_REG_IRQ_MSK		0x05
> +#define SX9324_CONVDONE_IRQ		BIT(3)
> +#define SX9324_FAR_IRQ			BIT(5)
> +#define SX9324_CLOSE_IRQ		BIT(6)
> +#define SX9324_REG_IRQ_CFG0		0x06
> +#define SX9324_REG_IRQ_CFG1		0x07
> +#define SX9324_REG_IRQ_CFG1_FAILCOND    0x80
> +#define SX9324_REG_IRQ_CFG2		0x08
> +
> +#define SX9324_REG_GNRL_CTRL0		0x10
> +#define SX9324_REG_GNRL_CTRL0_SCANPERIOD_MASK GENMASK(4, 0)
> +#define SX9324_REG_GNRL_CTRL0_SCANPERIOD_100MS 0x16
> +#define SX9324_REG_GNRL_CTRL1		0x11
> +#define SX9324_REG_GNRL_CTRL1_PHEN_MASK GENMASK(3, 0)
> +#define SX9324_REG_GNRL_CTRL1_PAUSECTRL 0x20
> +
> +#define SX9324_REG_I2C_ADDR		0x14
> +#define SX9324_REG_CLK_SPRD		0x15
> +
> +#define SX9324_REG_AFE_CTRL0		0x20
> +#define SX9324_REG_AFE_CTRL1		0x21
> +#define SX9324_REG_AFE_CTRL2		0x22
> +#define SX9324_REG_AFE_CTRL3		0x23
> +#define SX9324_REG_AFE_CTRL4		0x24
> +#define SX9324_REG_AFE_CTRL4_FREQ_83_33HZ 0x40
> +#define SX9324_REG_AFE_CTRL4_RESOLUTION_MASK GENMASK(2, 0)
> +#define SX9324_REG_AFE_CTRL4_RES_100	0x04
> +#define SX9324_REG_AFE_CTRL5		0x25
> +#define SX9324_REG_AFE_CTRL6		0x26
> +#define SX9324_REG_AFE_CTRL7		0x27
> +#define SX9324_REG_AFE_PH0		0x28
> +#define SX9324_REG_AFE_PH0_PIN_MASK(_pin) \
> +	GENMASK(2 * (_pin) + 1, 2 * (_pin))
> +
> +#define SX9324_REG_AFE_PH1		0x29
> +#define SX9324_REG_AFE_PH2		0x2a
> +#define SX9324_REG_AFE_PH3		0x2b
> +#define SX9324_REG_AFE_CTRL8		0x2c
> +#define SX9324_REG_AFE_CTRL8_RESFILTN_4KOHM 0x02
> +#define SX9324_REG_AFE_CTRL9		0x2d
> +#define SX9324_REG_AFE_CTRL9_AGAIN_1	0x08
> +
> +#define SX9324_REG_PROX_CTRL0		0x30
> +#define SX9324_REG_PROX_CTRL0_GAIN_MASK	GENMASK(5, 3)
> +#define SX9324_REG_PROX_CTRL0_GAIN_1		0x80
> +#define SX9324_REG_PROX_CTRL0_RAWFILT_1P50	0x01
> +#define SX9324_REG_PROX_CTRL1		0x31
> +#define SX9324_REG_PROX_CTRL2		0x32
> +#define SX9324_REG_PROX_CTRL2_AVGNEG_THRESH_16K 0x20
> +#define SX9324_REG_PROX_CTRL3		0x33
> +#define SX9324_REG_PROX_CTRL3_AVGDEB_2SAMPLES	0x40
> +#define SX9324_REG_PROX_CTRL3_AVGPOS_THRESH_16K 0x20
> +#define SX9324_REG_PROX_CTRL4		0x34
> +#define SX9324_REG_PROX_CTRL4_AVGNEGFILT_MASK	GENMASK(5, 3)
> +#define SX9324_REG_PROX_CTRL4_AVGNEG_FILT_2 0x08
> +#define SX9324_REG_PROX_CTRL4_AVGPOSFILT_MASK	GENMASK(2, 0)
> +#define SX9324_REG_PROX_CTRL3_AVGPOS_FILT_256 0x04
> +#define SX9324_REG_PROX_CTRL5		0x35
> +#define SX9324_REG_PROX_CTRL5_HYST_MASK			GENMASK(5, 4)
> +#define SX9324_REG_PROX_CTRL5_CLOSE_DEBOUNCE_MASK	GENMASK(3, 2)
> +#define SX9324_REG_PROX_CTRL5_FAR_DEBOUNCE_MASK		GENMASK(1, 0)
> +#define SX9324_REG_PROX_CTRL6		0x36
> +#define SX9324_REG_PROX_CTRL6_PROXTHRESH_32	0x08
> +#define SX9324_REG_PROX_CTRL7		0x37
> +
> +#define SX9324_REG_ADV_CTRL0		0x40
> +#define SX9324_REG_ADV_CTRL1		0x41
> +#define SX9324_REG_ADV_CTRL2		0x42
> +#define SX9324_REG_ADV_CTRL3		0x43
> +#define SX9324_REG_ADV_CTRL4		0x44
> +#define SX9324_REG_ADV_CTRL5		0x45
> +#define SX9324_REG_ADV_CTRL5_STARTUPSENS_MASK GENMASK(3, 2)
> +#define SX9324_REG_ADV_CTRL5_STARTUP_SENSOR_1	0x04
> +#define SX9324_REG_ADV_CTRL5_STARTUP_METHOD_1	0x01
> +#define SX9324_REG_ADV_CTRL6		0x46
> +#define SX9324_REG_ADV_CTRL7		0x47
> +#define SX9324_REG_ADV_CTRL8		0x48
> +#define SX9324_REG_ADV_CTRL9		0x49
> +#define SX9324_REG_ADV_CTRL10		0x4a
> +#define SX9324_REG_ADV_CTRL11		0x4b
> +#define SX9324_REG_ADV_CTRL12		0x4c
> +#define SX9324_REG_ADV_CTRL13		0x4d
> +#define SX9324_REG_ADV_CTRL14		0x4e
> +#define SX9324_REG_ADV_CTRL15		0x4f
> +#define SX9324_REG_ADV_CTRL16		0x50
> +#define SX9324_REG_ADV_CTRL17		0x51
> +#define SX9324_REG_ADV_CTRL18		0x52
> +#define SX9324_REG_ADV_CTRL19		0x53
> +#define SX9324_REG_ADV_CTRL20		0x54
> +#define SX9324_REG_ADV_CTRL19_HIGHT_FAILURE_THRESH_SATURATION 0xf0
> +
> +#define SX9324_REG_PHASE_SEL		0x60
> +
> +#define SX9324_REG_USEFUL_MSB		0x61
> +#define SX9324_REG_USEFUL_LSB		0x62
> +
> +#define SX9324_REG_AVG_MSB		0x63
> +#define SX9324_REG_AVG_LSB		0x64
> +
> +#define SX9324_REG_DIFF_MSB		0x65
> +#define SX9324_REG_DIFF_LSB		0x66
> +
> +#define SX9324_REG_OFFSET_MSB		0x67
> +#define SX9324_REG_OFFSET_LSB		0x68
> +
> +#define SX9324_REG_SAR_MSB		0x69
> +#define SX9324_REG_SAR_LSB		0x6a
> +
> +#define SX9324_REG_RESET		0x9f
> +/* Write this to REG_RESET to do a soft reset. */
> +#define SX9324_SOFT_RESET		0xde
> +
> +#define SX9324_REG_WHOAMI		0xfa
> +#define   SX9324_WHOAMI_VALUE		0x23
> +
> +#define SX9324_REG_REVISION		0xfe
> +
> +/* 4 channels, as defined in STAT0: PH0, PH1, PH2 and PH3. */
> +#define SX9324_NUM_CHANNELS		4
> +/* 3 CS pins: CS0, CS1, CS2. */
> +#define SX9324_NUM_PINS			3
> +
> +static const char * const sx9324_cs_pin_usage[] = { "HZ", "MI", "DS", "GD" };
> +
> +static ssize_t sx9324_phase_configuration_show(struct iio_dev *indio_dev,
> +					       uintptr_t private,
> +					       const struct iio_chan_spec *chan,
> +					       char *buf)
> +{
> +	struct sx_common_data *data = iio_priv(indio_dev);
> +	unsigned int val;
> +	int i, ret, pin_idx;
> +	size_t len = 0;
> +
> +	ret = regmap_read(data->regmap, SX9324_REG_AFE_PH0 + chan->channel, &val);
> +	if (ret < 0)
> +		return ret;
> +
> +	for (i = 0; i < SX9324_NUM_PINS; i++) {
> +		pin_idx = (val & SX9324_REG_AFE_PH0_PIN_MASK(i)) >> (2 * i);
> +		len += scnprintf(buf + len, PAGE_SIZE - len, "%s,",
> +				 sx9324_cs_pin_usage[pin_idx]);
> +	}
> +	buf[len - 1] = '\n';
> +	return len;
> +}
> +
> +static const struct iio_chan_spec_ext_info sx9324_channel_ext_info[] = {
> +	{
> +		.name = "setting",
> +		.shared = IIO_SEPARATE,
> +		.read = sx9324_phase_configuration_show,
> +	},
> +	{}
> +};
> +
> +#define SX9324_CHANNEL(idx)					 \
> +{								 \
> +	.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,						 \
> +	.address = SX9324_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,				 \
> +	},							 \
> +	.ext_info = sx9324_channel_ext_info,			 \
> +}
> +
> +static const struct iio_chan_spec sx9324_channels[] = {
> +	SX9324_CHANNEL(0),			/* Phase 0 */
> +	SX9324_CHANNEL(1),			/* Phase 1 */
> +	SX9324_CHANNEL(2),			/* Phase 2 */
> +	SX9324_CHANNEL(3),			/* Phase 3 */
> +	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;
> +} sx9324_samp_freq_table[] = {
> +	{1000, 0},  /* 00000: Min (no idle time) */
> +	{500, 0},  /* 00001: 2 ms */
> +	{250, 0},  /* 00010: 4 ms */
> +	{166, 666666},  /* 00011: 6 ms */
> +	{125, 0},  /* 00100: 8 ms */
> +	{100, 0},  /* 00101: 10 ms */
> +	{71, 428571},  /* 00110: 14 ms */
> +	{55, 555556},  /* 00111: 18 ms */
> +	{45, 454545},  /* 01000: 22 ms */
> +	{38, 461538},  /* 01001: 26 ms */
> +	{33, 333333},  /* 01010: 30 ms */
> +	{29, 411765},  /* 01011: 34 ms */
> +	{26, 315789},  /* 01100: 38 ms */
> +	{23, 809524},  /* 01101: 42 ms */
> +	{21, 739130},  /* 01110: 46 ms */
> +	{20, 0},  /* 01111: 50 ms */
> +	{17, 857143},  /* 10000: 56 ms */
> +	{16, 129032},  /* 10001: 62 ms */
> +	{14, 705882},  /* 10010: 68 ms */
> +	{13, 513514},  /* 10011: 74 ms */
> +	{12, 500000},  /* 10100: 80 ms */
> +	{11, 111111},  /* 10101: 90 ms */
> +	{10, 0},  /* 10110: 100 ms (Typ.) */
> +	{5, 0},  /* 10111: 200 ms */
> +	{3, 333333},  /* 11000: 300 ms */
> +	{2, 500000},  /* 11001: 400 ms */
> +	{1, 666667},  /* 11010: 600 ms */
> +	{1, 250000},  /* 11011: 800 ms */
> +	{1, 0},  /* 11100: 1 s */
> +	{0, 500000},  /* 11101: 2 s */
> +	{0, 333333},  /* 11110: 3 s */
> +	{0, 250000},  /* 11111: 4 s */
> +};
> +
> +static const unsigned int sx9324_scan_period_table[] = {
> +	2,   15,  30,  45,   60,   90,	 120,  200,
> +	400, 600, 800, 1000, 2000, 3000, 4000, 5000,
> +};
> +
> +static const struct regmap_range sx9324_writable_reg_ranges[] = {
> +	/*
> +	 * To set COMPSTAT for compensation, even if datasheet says register is
> +	 * RO.
> +	 */
> +	regmap_reg_range(SX9324_REG_STAT2, SX9324_REG_STAT2),
> +	regmap_reg_range(SX9324_REG_IRQ_MSK, SX9324_REG_IRQ_CFG2),
> +	regmap_reg_range(SX9324_REG_GNRL_CTRL0, SX9324_REG_GNRL_CTRL1),
> +	/* Leave i2c and clock spreading as unavailable */
> +	regmap_reg_range(SX9324_REG_AFE_CTRL0, SX9324_REG_AFE_CTRL9),
> +	regmap_reg_range(SX9324_REG_PROX_CTRL0, SX9324_REG_PROX_CTRL7),
> +	regmap_reg_range(SX9324_REG_ADV_CTRL0, SX9324_REG_ADV_CTRL20),
> +	regmap_reg_range(SX9324_REG_PHASE_SEL, SX9324_REG_PHASE_SEL),
> +	regmap_reg_range(SX9324_REG_OFFSET_MSB, SX9324_REG_OFFSET_LSB),
> +	regmap_reg_range(SX9324_REG_RESET, SX9324_REG_RESET),
> +};
> +
> +static const struct regmap_access_table sx9324_writeable_regs = {
> +	.yes_ranges = sx9324_writable_reg_ranges,
> +	.n_yes_ranges = ARRAY_SIZE(sx9324_writable_reg_ranges),
> +};
> +
> +/*
> + * All allocated registers are readable, so we just list unallocated
> + * ones.
> + */
> +static const struct regmap_range sx9324_non_readable_reg_ranges[] = {
> +	regmap_reg_range(SX9324_REG_IRQ_CFG2 + 1, SX9324_REG_GNRL_CTRL0 - 1),
> +	regmap_reg_range(SX9324_REG_GNRL_CTRL1 + 1, SX9324_REG_AFE_CTRL0 - 1),
> +	regmap_reg_range(SX9324_REG_AFE_CTRL9 + 1, SX9324_REG_PROX_CTRL0 - 1),
> +	regmap_reg_range(SX9324_REG_PROX_CTRL7 + 1, SX9324_REG_ADV_CTRL0 - 1),
> +	regmap_reg_range(SX9324_REG_ADV_CTRL20 + 1, SX9324_REG_PHASE_SEL - 1),
> +	regmap_reg_range(SX9324_REG_SAR_LSB + 1, SX9324_REG_RESET - 1),
> +	regmap_reg_range(SX9324_REG_RESET + 1, SX9324_REG_WHOAMI - 1),
> +	regmap_reg_range(SX9324_REG_WHOAMI + 1, SX9324_REG_REVISION - 1),
> +};
> +
> +static const struct regmap_access_table sx9324_readable_regs = {
> +	.no_ranges = sx9324_non_readable_reg_ranges,
> +	.n_no_ranges = ARRAY_SIZE(sx9324_non_readable_reg_ranges),
> +};
> +
> +static const struct regmap_range sx9324_volatile_reg_ranges[] = {
> +	regmap_reg_range(SX9324_REG_IRQ_SRC, SX9324_REG_STAT3),
> +	regmap_reg_range(SX9324_REG_USEFUL_MSB, SX9324_REG_DIFF_LSB),
> +	regmap_reg_range(SX9324_REG_SAR_MSB, SX9324_REG_SAR_LSB),
> +	regmap_reg_range(SX9324_REG_WHOAMI, SX9324_REG_WHOAMI),
> +	regmap_reg_range(SX9324_REG_REVISION, SX9324_REG_REVISION),
> +};
> +
> +static const struct regmap_access_table sx9324_volatile_regs = {
> +	.yes_ranges = sx9324_volatile_reg_ranges,
> +	.n_yes_ranges = ARRAY_SIZE(sx9324_volatile_reg_ranges),
> +};
> +
> +static const struct regmap_config sx9324_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +
> +	.max_register = SX9324_REG_REVISION,
> +	.cache_type = REGCACHE_RBTREE,
> +
> +	.wr_table = &sx9324_writeable_regs,
> +	.rd_table = &sx9324_readable_regs,
> +	.volatile_table = &sx9324_volatile_regs,
> +};
> +
> +static int sx9324_read_prox_data(struct sx_common_data *data,
> +				 const struct iio_chan_spec *chan,
> +				 __be16 *val)
> +{
> +	int ret;
> +
> +	ret = regmap_write(data->regmap, SX9324_REG_PHASE_SEL, chan->channel);
> +	if (ret < 0)
> +		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 sx9324_wait_for_sample(struct sx_common_data *data)
> +{
> +	int ret;
> +	unsigned int val;
> +
> +	ret = regmap_read(data->regmap, SX9324_REG_GNRL_CTRL0, &val);
> +	if (ret < 0)
> +		return ret;
> +	val = FIELD_GET(SX9324_REG_GNRL_CTRL0_SCANPERIOD_MASK, val);
> +
> +	msleep(sx9324_scan_period_table[val]);
> +
> +	return 0;
> +}
> +
> +static int sx9324_read_gain(struct sx_common_data *data,
> +			    const struct iio_chan_spec *chan, int *val)
> +{
> +	unsigned int reg, regval;
> +	int ret;
> +
> +	reg = SX9324_REG_PROX_CTRL0 + chan->channel / 2;
> +	ret = regmap_read(data->regmap, reg, &regval);
> +	if (ret)
> +		return ret;
> +
> +	*val = 1 << FIELD_GET(SX9324_REG_PROX_CTRL0_GAIN_MASK, regval);
> +
> +	return IIO_VAL_INT;
> +}
> +
> +static int sx9324_read_samp_freq(struct sx_common_data *data,
> +				 int *val, int *val2)
> +{
> +	int ret;
> +	unsigned int regval;
> +
> +	ret = regmap_read(data->regmap, SX9324_REG_GNRL_CTRL0, &regval);
> +	if (ret)
> +		return ret;
> +
> +	regval = FIELD_GET(SX9324_REG_GNRL_CTRL0_SCANPERIOD_MASK, regval);
> +	*val = sx9324_samp_freq_table[regval].val;
> +	*val2 = sx9324_samp_freq_table[regval].val2;
> +
> +	return IIO_VAL_INT_PLUS_MICRO;
> +}
> +
> +static int sx9324_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;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		ret = iio_device_claim_direct_mode(indio_dev);
> +		if (ret)
> +			return ret;
> +
> +		ret = sx_common_read_proximity(data, chan, val);
> +		iio_device_release_direct_mode(indio_dev);
> +		return ret;
> +	case IIO_CHAN_INFO_HARDWAREGAIN:
> +		ret = iio_device_claim_direct_mode(indio_dev);
> +		if (ret)
> +			return ret;
> +
> +		ret = sx9324_read_gain(data, chan, val);
> +		iio_device_release_direct_mode(indio_dev);
> +		return ret;
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		return sx9324_read_samp_freq(data, val, val2);
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static const int sx9324_gain_vals[] = { 1, 2, 4, 8 };
> +
> +static int sx9324_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(sx9324_gain_vals);
> +		*vals = sx9324_gain_vals;
> +		return IIO_AVAIL_LIST;
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		*type = IIO_VAL_INT_PLUS_MICRO;
> +		*length = ARRAY_SIZE(sx9324_samp_freq_table) * 2;
> +		*vals = (int *)sx9324_samp_freq_table;
> +		return IIO_AVAIL_LIST;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static int sx9324_set_samp_freq(struct sx_common_data *data,
> +				int val, int val2)
> +{
> +	int i, ret;
> +
> +	for (i = 0; i < ARRAY_SIZE(sx9324_samp_freq_table); i++)
> +		if (val == sx9324_samp_freq_table[i].val &&
> +		    val2 == sx9324_samp_freq_table[i].val2)
> +			break;
> +
> +	if (i == ARRAY_SIZE(sx9324_samp_freq_table))
> +		return -EINVAL;
> +
> +	mutex_lock(&data->mutex);
> +
> +	ret = regmap_update_bits(data->regmap,
> +				 SX9324_REG_GNRL_CTRL0,
> +				 SX9324_REG_GNRL_CTRL0_SCANPERIOD_MASK, i);
> +
> +	mutex_unlock(&data->mutex);
> +
> +	return ret;
> +}
> +
> +static int sx9324_read_thresh(struct sx_common_data *data,
> +			      const struct iio_chan_spec *chan, int *val)
> +{
> +	unsigned int regval;
> +	unsigned int reg;
> +	int ret;
> +
> +	/*
> +	 * TODO(gwendal): Depending on the phase function
> +	 * (proximity/table/body), retrieve the right threshold.
> +	 * For now, return the proximity threshold.
> +	 */
> +	reg = SX9324_REG_PROX_CTRL6 + chan->channel / 2;
> +	ret = regmap_read(data->regmap, reg, &regval);
> +	if (ret)
> +		return ret;
> +
> +	if (regval <= 1)
> +		*val = regval;
> +	else
> +		*val = (regval * regval) / 2;
> +
> +	return IIO_VAL_INT;
> +}
> +
> +static int sx9324_read_hysteresis(struct sx_common_data *data,
> +				  const struct iio_chan_spec *chan, int *val)
> +{
> +	unsigned int regval, pthresh;
> +	int ret;
> +
> +	ret = sx9324_read_thresh(data, chan, &pthresh);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = regmap_read(data->regmap, SX9324_REG_PROX_CTRL5, &regval);
> +	if (ret)
> +		return ret;
> +
> +	regval = FIELD_GET(SX9324_REG_PROX_CTRL5_HYST_MASK, regval);
> +	if (!regval)
> +		*val = 0;
> +	else
> +		*val = pthresh >> (5 - regval);
> +
> +	return IIO_VAL_INT;
> +}
> +
> +static int sx9324_read_far_debounce(struct sx_common_data *data, int *val)
> +{
> +	unsigned int regval;
> +	int ret;
> +
> +	ret = regmap_read(data->regmap, SX9324_REG_PROX_CTRL5, &regval);
> +	if (ret)
> +		return ret;
> +
> +	regval = FIELD_GET(SX9324_REG_PROX_CTRL5_FAR_DEBOUNCE_MASK, regval);
> +	if (regval)
> +		*val = 1 << regval;
> +	else
> +		*val = 0;
> +
> +	return IIO_VAL_INT;
> +}
> +
> +static int sx9324_read_close_debounce(struct sx_common_data *data, int *val)
> +{
> +	unsigned int regval;
> +	int ret;
> +
> +	ret = regmap_read(data->regmap, SX9324_REG_PROX_CTRL5, &regval);
> +	if (ret)
> +		return ret;
> +
> +	regval = FIELD_GET(SX9324_REG_PROX_CTRL5_CLOSE_DEBOUNCE_MASK, regval);
> +	if (regval)
> +		*val = 1 << regval;
> +	else
> +		*val = 0;
> +
> +	return IIO_VAL_INT;
> +}
> +
> +static int sx9324_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 sx9324_read_thresh(data, chan, val);
> +	case IIO_EV_INFO_PERIOD:
> +		switch (dir) {
> +		case IIO_EV_DIR_RISING:
> +			return sx9324_read_far_debounce(data, val);
> +		case IIO_EV_DIR_FALLING:
> +			return sx9324_read_close_debounce(data, val);
> +		default:
> +			return -EINVAL;
> +		}
> +	case IIO_EV_INFO_HYSTERESIS:
> +		return sx9324_read_hysteresis(data, chan, val);
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int sx9324_write_thresh(struct sx_common_data *data,
> +			       const struct iio_chan_spec *chan, int _val)
> +{
> +	unsigned int reg, val = _val;
> +	int ret;
> +
> +	reg = SX9324_REG_PROX_CTRL6 + chan->channel / 2;
> +
> +	if (val >= 1)
> +		val = int_sqrt(2 * val);
> +
> +	if (val > 0xff)
> +		return -EINVAL;
> +
> +	mutex_lock(&data->mutex);
> +	ret = regmap_write(data->regmap, reg, val);
> +	mutex_unlock(&data->mutex);
> +
> +	return ret;
> +}
> +
> +static int sx9324_write_hysteresis(struct sx_common_data *data,
> +				   const struct iio_chan_spec *chan, int _val)
> +{
> +	unsigned int hyst, val = _val;
> +	int ret, pthresh;
> +
> +	ret = sx9324_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(SX9324_REG_PROX_CTRL5_HYST_MASK, hyst);
> +	mutex_lock(&data->mutex);
> +	ret = regmap_update_bits(data->regmap, SX9324_REG_PROX_CTRL5,
> +				 SX9324_REG_PROX_CTRL5_HYST_MASK, hyst);
> +	mutex_unlock(&data->mutex);
> +
> +	return ret;
> +}
> +
> +static int sx9324_write_far_debounce(struct sx_common_data *data, int _val)
> +{
> +	unsigned int regval, val = _val;
> +	int ret;
> +
> +	if (val > 0)
> +		val = ilog2(val);
> +	if (!FIELD_FIT(SX9324_REG_PROX_CTRL5_FAR_DEBOUNCE_MASK, val))
> +		return -EINVAL;
> +
> +	regval = FIELD_PREP(SX9324_REG_PROX_CTRL5_FAR_DEBOUNCE_MASK, val);
> +
> +	mutex_lock(&data->mutex);
> +	ret = regmap_update_bits(data->regmap, SX9324_REG_PROX_CTRL5,
> +				 SX9324_REG_PROX_CTRL5_FAR_DEBOUNCE_MASK,
> +				 regval);
> +	mutex_unlock(&data->mutex);
> +
> +	return ret;
> +}
> +
> +static int sx9324_write_close_debounce(struct sx_common_data *data, int _val)
> +{
> +	unsigned int regval, val = _val;
> +	int ret;
> +
> +	if (val > 0)
> +		val = ilog2(val);
> +	if (!FIELD_FIT(SX9324_REG_PROX_CTRL5_CLOSE_DEBOUNCE_MASK, val))
> +		return -EINVAL;
> +
> +	regval = FIELD_PREP(SX9324_REG_PROX_CTRL5_CLOSE_DEBOUNCE_MASK, val);
> +
> +	mutex_lock(&data->mutex);
> +	ret = regmap_update_bits(data->regmap, SX9324_REG_PROX_CTRL5,
> +				 SX9324_REG_PROX_CTRL5_CLOSE_DEBOUNCE_MASK,
> +				 regval);
> +	mutex_unlock(&data->mutex);
> +
> +	return ret;
> +}
> +
> +static int sx9324_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 sx9324_write_thresh(data, chan, val);
> +	case IIO_EV_INFO_PERIOD:
> +		switch (dir) {
> +		case IIO_EV_DIR_RISING:
> +			return sx9324_write_far_debounce(data, val);
> +		case IIO_EV_DIR_FALLING:
> +			return sx9324_write_close_debounce(data, val);
> +		default:
> +			return -EINVAL;
> +		}
> +	case IIO_EV_INFO_HYSTERESIS:
> +		return sx9324_write_hysteresis(data, chan, val);
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int sx9324_write_gain(struct sx_common_data *data,
> +			     const struct iio_chan_spec *chan, int val)
> +{
> +	unsigned int gain, reg;
> +	int ret;
> +
> +	gain = ilog2(val);
> +	reg = SX9324_REG_PROX_CTRL0 + chan->channel / 2;
> +	gain = FIELD_PREP(SX9324_REG_PROX_CTRL0_GAIN_MASK, gain);
> +
> +	mutex_lock(&data->mutex);
> +	ret = regmap_update_bits(data->regmap, reg,
> +				 SX9324_REG_PROX_CTRL0_GAIN_MASK,
> +				 gain);
> +	mutex_unlock(&data->mutex);
> +
> +	return ret;
> +}
> +
> +static int sx9324_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);
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		return sx9324_set_samp_freq(data, val, val2);
> +	case IIO_CHAN_INFO_HARDWAREGAIN:
> +		return sx9324_write_gain(data, chan, val);
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +/* Activate all channels and perform an initial compensation. */
> +static int sx9324_init_compensation(struct iio_dev *indio_dev)
> +{
> +	struct sx_common_data *data = iio_priv(indio_dev);
> +	unsigned int val;
> +	int ret;
> +
> +	/* run the compensation phase on all channels */
> +	ret = regmap_update_bits(data->regmap, SX9324_REG_STAT2,
> +				 SX9324_REG_STAT2_COMPSTAT_MASK,
> +				 SX9324_REG_STAT2_COMPSTAT_MASK);
> +	if (ret)
> +		return ret;
> +
> +	ret = regmap_read_poll_timeout(data->regmap, SX9324_REG_STAT2, val,
> +				       !(val & SX9324_REG_STAT2_COMPSTAT_MASK),
> +				       20000, 2000000);
> +	if (ret == -ETIMEDOUT)
> +		dev_err(&data->client->dev,
> +			"initial compensation timed out: 0x%02x\n",
> +			val);
> +	return ret;
> +}
> +
> +static int sx9324_check_whoami(struct device *dev,
> +			       struct iio_dev *indio_dev)
> +{
> +	/*
> +	 * Only one sensor for this driver. Assuming the device tree
> +	 * is correct, just set the sensor name.
> +	 */
> +	indio_dev->name = "sx9324";
> +	return 0;
> +}
> +
> +static const struct sx_common_chip_info sx9324_chip_info = {
> +	.reg_stat = SX9324_REG_STAT0,
> +	.reg_irq_msk = SX9324_REG_IRQ_MSK,
> +	.reg_enable_chan = SX9324_REG_GNRL_CTRL1,
> +	.reg_reset = SX9324_REG_RESET,
> +
> +	.mask_enable_chan = SX9324_REG_GNRL_CTRL1_PHEN_MASK,
> +	.irq_msk_offset = 3,
> +	.num_channels = SX9324_NUM_CHANNELS,
> +
> +	.ops = {
> +		.read_prox_data = sx9324_read_prox_data,
> +		.check_whoami = sx9324_check_whoami,
> +		.init_compensation = sx9324_init_compensation,
> +		.wait_for_sample = sx9324_wait_for_sample,
> +	},
> +
> +	.iio_channels = sx9324_channels,
> +	.num_iio_channels = ARRAY_SIZE(sx9324_channels),
> +	.iio_info =  {
> +		.read_raw = sx9324_read_raw,
> +		.read_avail = sx9324_read_avail,
> +		.read_event_value = sx9324_read_event_val,
> +		.write_event_value = sx9324_write_event_val,
> +		.write_raw = sx9324_write_raw,
> +		.read_event_config = sx_common_read_event_config,
> +		.write_event_config = sx_common_write_event_config,
> +	},
> +};
> +
> +static int sx9324_probe(struct i2c_client *client)
> +{
> +	return sx_common_probe(client, &sx9324_chip_info, &sx9324_regmap_config);
> +}
> +
> +static int __maybe_unused sx9324_suspend(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> +	struct sx_common_data *data = iio_priv(indio_dev);
> +	unsigned int regval;
> +	int ret;
> +
> +	disable_irq_nosync(data->client->irq);
> +
> +	mutex_lock(&data->mutex);
> +	ret = regmap_read(data->regmap, SX9324_REG_GNRL_CTRL1, &regval);
> +
> +	data->suspend_ctrl =
> +		FIELD_GET(SX9324_REG_GNRL_CTRL1_PHEN_MASK, regval);
> +
> +	if (ret < 0)
> +		goto out;
> +
> +	/* Disable all phases, send the device to sleep. */
> +	ret = regmap_write(data->regmap, SX9324_REG_GNRL_CTRL1, 0);
> +
> +out:
> +	mutex_unlock(&data->mutex);
> +	return ret;
> +}
> +
> +static int __maybe_unused sx9324_resume(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> +	struct sx_common_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	mutex_lock(&data->mutex);
> +	ret = regmap_write(data->regmap, SX9324_REG_GNRL_CTRL1,
> +			   data->suspend_ctrl | SX9324_REG_GNRL_CTRL1_PAUSECTRL);
> +	mutex_unlock(&data->mutex);
> +	if (ret)
> +		return ret;
> +
> +	enable_irq(data->client->irq);
> +	return 0;
> +}
> +
> +static const struct dev_pm_ops sx9324_pm_ops = {
> +	SET_SYSTEM_SLEEP_PM_OPS(sx9324_suspend, sx9324_resume)
> +};
> +
> +static const struct acpi_device_id sx9324_acpi_match[] = {
> +	{ "STH9324", SX9324_WHOAMI_VALUE},
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(acpi, sx9324_acpi_match);
> +
> +static const struct of_device_id sx9324_of_match[] = {
> +	{ .compatible = "semtech,sx9324", (void *)SX9324_WHOAMI_VALUE},
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, sx9324_of_match);
> +
> +static const struct i2c_device_id sx9324_id[] = {
> +	{"sx9324", SX9324_WHOAMI_VALUE},
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, sx9324_id);
> +
> +static struct i2c_driver sx9324_driver = {
> +	.driver = {
> +		.name	= "sx9324",
> +		.acpi_match_table = sx9324_acpi_match,
> +		.of_match_table = sx9324_of_match,
> +		.pm = &sx9324_pm_ops,
> +
> +		/*
> +		 * Lots of i2c transfers in probe + over 200 ms waiting in
> +		 * sx9324_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_new	= sx9324_probe,
> +	.id_table	= sx9324_id,
> +};
> +module_i2c_driver(sx9324_driver);
> +
> +MODULE_AUTHOR("Gwendal Grignou <gwendal@chromium.org>");
> +MODULE_DESCRIPTION("Driver for Semtech SX9324 proximity sensor");
> +MODULE_LICENSE("GPL v2");