[PATCH v4 0/3] Add Semtech SX9360 SAR Sensor support

[PATCH v4 0/3] Add Semtech SX9360 SAR Sensor support

[Gwendal Grignou]

Add a new Semtech SAR sensor SX9360.
It is a simpler version of SX9324, with only one phase instead of 4.
Leverage sx_common.h interface defined when SX9324 was added.

Major changes since v3:
- Remove "reference" as a new modifier: it is not needed, indexed
  channels and labels are used instead.
- Use dev_get_drvdata to access iio device structure.

Major changes since v2:
- Register "modifier" as a new modifier.
- Fix device tree binding syntax
- Fix issues reported during sx9324 driver review:
  - fix include with iwyu

Major changes since v1:
- Integrate errors found in sx9324 driver.
- Simplify whomai function.
- Fix cut and paste in bindings.
- Handle negative sysfs parameters.

Gwendal Grignou (3):
  iio: proximity: Add sx9360 support
  dt-bindings: iio: Add sx9360 binding
  iio: sx9360: Add dt-binding support

 .../iio/proximity/semtech,sx9360.yaml         |  89 ++
 drivers/iio/proximity/Kconfig                 |  14 +
 drivers/iio/proximity/Makefile                |   1 +
 drivers/iio/proximity/sx9360.c                | 900 ++++++++++++++++++
 4 files changed, 1004 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/proximity/semtech,sx9360.yaml
 create mode 100644 drivers/iio/proximity/sx9360.c

-- 
2.34.1.173.g76aa8bc2d0-goog

[PATCH v4 1/3] iio: proximity: Add sx9360 support

[Gwendal Grignou]

A simplified version of SX9324, it only have one pin and
2 phases (aka channels).
Only one event is presented.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
---
Changes since v3:
- Remove "reference" as a new modifier: it is not needed, indexed
  channels and labels are used instead.
- Use dev_get_drvdata to access iio device structure.
- Use already calculated local variable
- Use default: clause to return when possible.

Changes since v2:
- Fix issues reported during sx9324 driver review:
  - fix include with iwyu
  - Remove call to ACPI_PTR to prevent unused variable warning.
- Fix panic when setting frequency to 0.
- Add offset to decipher interrupt register
- Fix default register value.

Changes since v1:
- Remove SX9360_DRIVER_NAME
- Simplify whoami function
- Define WHOAMI register value internally.
- Handle negative values when setting sysfs parameters.

 drivers/iio/proximity/Kconfig  |  14 +
 drivers/iio/proximity/Makefile |   1 +
 drivers/iio/proximity/sx9360.c | 816 +++++++++++++++++++++++++++++++++
 3 files changed, 831 insertions(+)
 create mode 100644 drivers/iio/proximity/sx9360.c

diff --git a/drivers/iio/proximity/Kconfig b/drivers/iio/proximity/Kconfig
index dc66f339e5b12a..0e5c17530b8bb4 100644
--- a/drivers/iio/proximity/Kconfig
+++ b/drivers/iio/proximity/Kconfig
@@ -145,6 +145,20 @@ config SX9324
 	  To compile this driver as a module, choose M here: the
 	  module will be called sx9324.
 
+config SX9360
+	tristate "SX9360 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 SX9360
+	  proximity/button sensor, a simplified SX9324.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called sx9360.
+
 config SX9500
 	tristate "SX9500 Semtech proximity sensor"
 	select IIO_BUFFER
diff --git a/drivers/iio/proximity/Makefile b/drivers/iio/proximity/Makefile
index cffe962b352718..cc838bb5408a89 100644
--- a/drivers/iio/proximity/Makefile
+++ b/drivers/iio/proximity/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_SRF04)		+= srf04.o
 obj-$(CONFIG_SRF08)		+= srf08.o
 obj-$(CONFIG_SX9310)		+= sx9310.o
 obj-$(CONFIG_SX9324)		+= sx9324.o
+obj-$(CONFIG_SX9360)		+= sx9360.o
 obj-$(CONFIG_SX_COMMON) 	+= sx_common.o
 obj-$(CONFIG_SX9500)		+= sx9500.o
 obj-$(CONFIG_VCNL3020)		+= vcnl3020.o
diff --git a/drivers/iio/proximity/sx9360.c b/drivers/iio/proximity/sx9360.c
new file mode 100644
index 00000000000000..75788bbf70efac
--- /dev/null
+++ b/drivers/iio/proximity/sx9360.c
@@ -0,0 +1,816 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2021 Google LLC.
+ *
+ * Driver for Semtech's SX9360 capacitive proximity/button solution.
+ * Based on SX9360 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/regmap.h>
+
+#include <linux/iio/iio.h>
+
+#include "sx_common.h"
+
+/* Nominal Oscillator Frequency. */
+#define SX9360_FOSC_MHZ			4
+#define SX9360_FOSC_HZ			(SX9360_FOSC_MHZ * 1000000)
+
+/* Register definitions. */
+#define SX9360_REG_IRQ_SRC		SX_COMMON_REG_IRQ_SRC
+#define SX9360_REG_STAT		0x01
+#define SX9360_REG_STAT_COMPSTAT_MASK	GENMASK(2, 1)
+#define SX9360_REG_IRQ_MSK		0x02
+#define SX9360_CONVDONE_IRQ		BIT(0)
+#define SX9360_FAR_IRQ			BIT(2)
+#define SX9360_CLOSE_IRQ		BIT(3)
+#define SX9360_REG_IRQ_CFG		0x03
+
+#define SX9360_REG_GNRL_CTRL0		0x10
+#define SX9360_REG_GNRL_CTRL0_PHEN_MASK GENMASK(1, 0)
+#define SX9360_REG_GNRL_CTRL1		0x11
+#define SX9360_REG_GNRL_CTRL1_SCANPERIOD_MASK GENMASK(2, 0)
+#define SX9360_REG_GNRL_CTRL2		0x12
+#define SX9360_REG_GNRL_CTRL2_PERIOD_102MS	0x32
+#define SX9360_REG_GNRL_REG_2_PERIOD_MS(_r)	\
+	(((_r) * 8192) / (SX9360_FOSC_HZ / 1000))
+#define SX9360_REG_GNRL_FREQ_2_REG(_f)  (((_f) * 8192) / SX9360_FOSC_HZ)
+#define SX9360_REG_GNRL_REG_2_FREQ(_r)  (SX9360_FOSC_HZ / ((_r) * 8192))
+
+#define SX9360_REG_AFE_CTRL1		0x21
+#define SX9360_REG_AFE_PARAM0_PHR	0x22
+#define SX9360_REG_AFE_PARAM1_PHR	0x23
+#define SX9360_REG_AFE_PARAM0_PHM	0x24
+#define SX9360_REG_AFE_PARAM0_RSVD		0x08
+#define SX9360_REG_AFE_PARAM0_RESOLUTION_MASK	GENMASK(2, 0)
+#define SX9360_REG_AFE_PARAM0_RESOLUTION_128	0x02
+#define SX9360_REG_AFE_PARAM1_PHM	0x25
+#define SX9360_REG_AFE_PARAM1_AGAIN_PHM_6PF	0x40
+#define SX9360_REG_AFE_PARAM1_FREQ_83_33HZ	0x06
+
+#define SX9360_REG_PROX_CTRL0_PHR	0x40
+#define SX9360_REG_PROX_CTRL0_PHM	0x41
+#define SX9360_REG_PROX_CTRL0_GAIN_MASK	GENMASK(5, 3)
+#define SX9360_REG_PROX_CTRL0_GAIN_1		0x80
+#define SX9360_REG_PROX_CTRL0_RAWFILT_1P50	0x01
+#define SX9360_REG_PROX_CTRL1		0x42
+#define SX9360_REG_PROX_CTRL1_AVGNEG_THRESH_MASK	GENMASK(5, 3)
+#define SX9360_REG_PROX_CTRL1_AVGNEG_THRESH_16K 0x20
+#define SX9360_REG_PROX_CTRL2		0x43
+#define SX9360_REG_PROX_CTRL2_AVGDEB_MASK	GENMASK(7, 6)
+#define SX9360_REG_PROX_CTRL2_AVGDEB_2SAMPLES	0x40
+#define SX9360_REG_PROX_CTRL2_AVGPOS_THRESH_16K	0x20
+#define SX9360_REG_PROX_CTRL3		0x44
+#define SX9360_REG_PROX_CTRL3_AVGNEG_FILT_MASK	GENMASK(5, 3)
+#define SX9360_REG_PROX_CTRL3_AVGNEG_FILT_2	0x08
+#define SX9360_REG_PROX_CTRL3_AVGPOS_FILT_MASK	GENMASK(2, 0)
+#define SX9360_REG_PROX_CTRL3_AVGPOS_FILT_256	0x04
+#define SX9360_REG_PROX_CTRL4		0x45
+#define SX9360_REG_PROX_CTRL4_HYST_MASK			GENMASK(5, 4)
+#define SX9360_REG_PROX_CTRL4_CLOSE_DEBOUNCE_MASK	GENMASK(3, 2)
+#define SX9360_REG_PROX_CTRL4_FAR_DEBOUNCE_MASK		GENMASK(1, 0)
+#define SX9360_REG_PROX_CTRL5		0x46
+#define SX9360_REG_PROX_CTRL5_PROXTHRESH_32	0x08
+
+#define SX9360_REG_REF_CORR0		0x60
+#define SX9360_REG_REF_CORR1		0x61
+
+#define SX9360_REG_USEFUL_PHR_MSB		0x90
+#define SX9360_REG_USEFUL_PHR_LSB		0x91
+
+#define SX9360_REG_OFFSET_PMR_MSB		0x92
+#define SX9360_REG_OFFSET_PMR_LSB		0x93
+
+#define SX9360_REG_USEFUL_PHM_MSB		0x94
+#define SX9360_REG_USEFUL_PHM_LSB		0x95
+
+#define SX9360_REG_AVG_PHM_MSB		0x96
+#define SX9360_REG_AVG_PHM_LSB		0x97
+
+#define SX9360_REG_DIFF_PHM_MSB		0x98
+#define SX9360_REG_DIFF_PHM_LSB		0x99
+
+#define SX9360_REG_OFFSET_PHM_MSB		0x9a
+#define SX9360_REG_OFFSET_PHM_LSB		0x9b
+
+#define SX9360_REG_USE_FILTER_MSB		0x9a
+#define SX9360_REG_USE_FILTER_LSB		0x9b
+
+#define SX9360_REG_RESET		0xcf
+/* Write this to REG_RESET to do a soft reset. */
+#define SX9360_SOFT_RESET		0xde
+
+#define SX9360_REG_WHOAMI		0xfa
+#define   SX9360_WHOAMI_VALUE				0x60
+
+#define SX9360_REG_REVISION		0xfe
+
+/* 2 channels, Phase Reference and Measurement. */
+#define SX9360_NUM_CHANNELS		2
+
+static const struct iio_chan_spec sx9360_channels[] = {
+	{
+		.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,
+		.address = SX9360_REG_USEFUL_PHR_MSB,
+		.channel = 0,
+		.scan_index = 0,
+		.scan_type = {
+			.sign = 's',
+			.realbits = 12,
+			.storagebits = 16,
+			.endianness = IIO_BE,
+		},
+	},
+	{
+		.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,
+		.address = SX9360_REG_USEFUL_PHM_MSB,
+		.event_spec = sx_common_events,
+		.num_event_specs = ARRAY_SIZE(sx_common_events),
+		.channel = 1,
+		.scan_index = 1,
+		.scan_type = {
+			.sign = 's',
+			.realbits = 12,
+			.storagebits = 16,
+			.endianness = IIO_BE,
+		},
+	},
+	IIO_CHAN_SOFT_TIMESTAMP(2),
+};
+
+/*
+ * 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.
+ *
+ * The frequency control register holds the period, with a ~2ms increment.
+ * Therefore the smallest frequency is 4MHz / (2047 * 8192),
+ * The fastest is 4MHz / 8192.
+ * The interval is not linear, but given there is 2047 possible value,
+ * Returns the fake increment of (Max-Min)/2047
+ *
+ */
+static const struct {
+	int val;
+	int val2;
+} sx9360_samp_freq_interval[] = {
+	{0, 281250},  /* 4MHz / (8192 * 2047) */
+	{0, 281250},
+	{448, 281250},  /* 4MHz / 8192 */
+};
+
+static const struct regmap_range sx9360_writable_reg_ranges[] = {
+	/*
+	 * To set COMPSTAT for compensation, even if datasheet says register is
+	 * RO.
+	 */
+	regmap_reg_range(SX9360_REG_STAT, SX9360_REG_IRQ_CFG),
+	regmap_reg_range(SX9360_REG_GNRL_CTRL0, SX9360_REG_GNRL_CTRL2),
+	regmap_reg_range(SX9360_REG_AFE_CTRL1, SX9360_REG_AFE_PARAM1_PHM),
+	regmap_reg_range(SX9360_REG_PROX_CTRL0_PHR, SX9360_REG_PROX_CTRL5),
+	regmap_reg_range(SX9360_REG_REF_CORR0, SX9360_REG_REF_CORR1),
+	regmap_reg_range(SX9360_REG_OFFSET_PMR_MSB, SX9360_REG_OFFSET_PMR_LSB),
+	regmap_reg_range(SX9360_REG_RESET, SX9360_REG_RESET),
+};
+
+static const struct regmap_access_table sx9360_writeable_regs = {
+	.yes_ranges = sx9360_writable_reg_ranges,
+	.n_yes_ranges = ARRAY_SIZE(sx9360_writable_reg_ranges),
+};
+
+/*
+ * All allocated registers are readable, so we just list unallocated
+ * ones.
+ */
+static const struct regmap_range sx9360_non_readable_reg_ranges[] = {
+	regmap_reg_range(SX9360_REG_IRQ_CFG + 1, SX9360_REG_GNRL_CTRL0 - 1),
+	regmap_reg_range(SX9360_REG_GNRL_CTRL2 + 1, SX9360_REG_AFE_CTRL1 - 1),
+	regmap_reg_range(SX9360_REG_AFE_PARAM1_PHM + 1,
+			 SX9360_REG_PROX_CTRL0_PHR - 1),
+	regmap_reg_range(SX9360_REG_PROX_CTRL5 + 1, SX9360_REG_REF_CORR0 - 1),
+	regmap_reg_range(SX9360_REG_REF_CORR1 + 1,
+			 SX9360_REG_USEFUL_PHR_MSB - 1),
+	regmap_reg_range(SX9360_REG_USE_FILTER_LSB + 1, SX9360_REG_RESET - 1),
+	regmap_reg_range(SX9360_REG_RESET + 1, SX9360_REG_WHOAMI - 1),
+	regmap_reg_range(SX9360_REG_WHOAMI + 1, SX9360_REG_REVISION - 1),
+};
+
+static const struct regmap_access_table sx9360_readable_regs = {
+	.no_ranges = sx9360_non_readable_reg_ranges,
+	.n_no_ranges = ARRAY_SIZE(sx9360_non_readable_reg_ranges),
+};
+
+static const struct regmap_range sx9360_volatile_reg_ranges[] = {
+	regmap_reg_range(SX9360_REG_IRQ_SRC, SX9360_REG_STAT),
+	regmap_reg_range(SX9360_REG_USEFUL_PHR_MSB, SX9360_REG_USE_FILTER_LSB),
+	regmap_reg_range(SX9360_REG_WHOAMI, SX9360_REG_WHOAMI),
+	regmap_reg_range(SX9360_REG_REVISION, SX9360_REG_REVISION),
+};
+
+static const struct regmap_access_table sx9360_volatile_regs = {
+	.yes_ranges = sx9360_volatile_reg_ranges,
+	.n_yes_ranges = ARRAY_SIZE(sx9360_volatile_reg_ranges),
+};
+
+static const struct regmap_config sx9360_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = SX9360_REG_REVISION,
+	.cache_type = REGCACHE_RBTREE,
+
+	.wr_table = &sx9360_writeable_regs,
+	.rd_table = &sx9360_readable_regs,
+	.volatile_table = &sx9360_volatile_regs,
+};
+
+static int sx9360_read_prox_data(struct sx_common_data *data,
+				 const struct iio_chan_spec *chan,
+				 __be16 *val)
+{
+	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 sx9360_wait_for_sample(struct sx_common_data *data)
+{
+	int ret;
+	__be16 buf;
+
+	ret = regmap_bulk_read(data->regmap, SX9360_REG_GNRL_CTRL1,
+			       &buf, sizeof(buf));
+	if (ret < 0)
+		return ret;
+	msleep(SX9360_REG_GNRL_REG_2_PERIOD_MS(be16_to_cpu(buf)));
+
+	return 0;
+}
+
+static int sx9360_read_gain(struct sx_common_data *data,
+			    const struct iio_chan_spec *chan, int *val)
+{
+	unsigned int reg, regval;
+	int ret;
+
+	reg = SX9360_REG_PROX_CTRL0_PHR + chan->channel;
+	ret = regmap_read(data->regmap, reg, &regval);
+	if (ret)
+		return ret;
+
+	*val = 1 << FIELD_GET(SX9360_REG_PROX_CTRL0_GAIN_MASK, regval);
+
+	return IIO_VAL_INT;
+}
+
+static int sx9360_read_samp_freq(struct sx_common_data *data,
+				 int *val, int *val2)
+{
+	int ret, divisor;
+	__be16 buf;
+
+	ret = regmap_bulk_read(data->regmap, SX9360_REG_GNRL_CTRL1,
+			       &buf, sizeof(buf));
+	if (ret < 0)
+		return ret;
+	divisor = be16_to_cpu(buf);
+	if (divisor == 0) {
+		*val = 0;
+		return IIO_VAL_INT;
+	}
+
+	*val = SX9360_FOSC_HZ;
+	*val2 = divisor * 8192;
+
+	return IIO_VAL_FRACTIONAL;
+}
+
+static int sx9360_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 = sx9360_read_gain(data, chan, val);
+		iio_device_release_direct_mode(indio_dev);
+		return ret;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		return sx9360_read_samp_freq(data, val, val2);
+	default:
+		return -EINVAL;
+	}
+}
+
+static const char *sx9360_channel_labels[SX9360_NUM_CHANNELS] = {
+	"reference", "main",
+};
+
+static int sx9360_read_label(struct iio_dev *iio_dev, const struct iio_chan_spec *chan,
+			     char *label)
+{
+	return snprintf(label, PAGE_SIZE, "%s\n", sx9360_channel_labels[chan->channel]);
+}
+
+static const int sx9360_gain_vals[] = { 1, 2, 4, 8 };
+
+static int sx9360_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(sx9360_gain_vals);
+		*vals = sx9360_gain_vals;
+		return IIO_AVAIL_LIST;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*type = IIO_VAL_INT_PLUS_MICRO;
+		*length = ARRAY_SIZE(sx9360_samp_freq_interval) * 2;
+		*vals = (int *)sx9360_samp_freq_interval;
+		return IIO_AVAIL_RANGE;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int sx9360_set_samp_freq(struct sx_common_data *data,
+				int val, int val2)
+{
+	int ret, reg;
+	__be16 buf;
+
+	reg = val * 8192 / SX9360_FOSC_HZ + val2 * 8192 / (SX9360_FOSC_MHZ);
+	buf = cpu_to_be16(val);
+	mutex_lock(&data->mutex);
+
+	ret = regmap_bulk_write(data->regmap, SX9360_REG_GNRL_CTRL1, &buf,
+				sizeof(buf));
+
+	mutex_unlock(&data->mutex);
+
+	return ret;
+}
+
+static int sx9360_read_thresh(struct sx_common_data *data, int *val)
+{
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(data->regmap, SX9360_REG_PROX_CTRL5, &regval);
+	if (ret)
+		return ret;
+
+	if (regval <= 1)
+		*val = regval;
+	else
+		*val = (regval * regval) / 2;
+
+	return IIO_VAL_INT;
+}
+
+static int sx9360_read_hysteresis(struct sx_common_data *data, int *val)
+{
+	unsigned int regval, pthresh;
+	int ret;
+
+	ret = sx9360_read_thresh(data, &pthresh);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_read(data->regmap, SX9360_REG_PROX_CTRL4, &regval);
+	if (ret)
+		return ret;
+
+	regval = FIELD_GET(SX9360_REG_PROX_CTRL4_HYST_MASK, regval);
+	if (!regval)
+		*val = 0;
+	else
+		*val = pthresh >> (5 - regval);
+
+	return IIO_VAL_INT;
+}
+
+static int sx9360_read_far_debounce(struct sx_common_data *data, int *val)
+{
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(data->regmap, SX9360_REG_PROX_CTRL4, &regval);
+	if (ret)
+		return ret;
+
+	regval = FIELD_GET(SX9360_REG_PROX_CTRL4_FAR_DEBOUNCE_MASK, regval);
+	if (regval)
+		*val = 1 << regval;
+	else
+		*val = 0;
+
+	return IIO_VAL_INT;
+}
+
+static int sx9360_read_close_debounce(struct sx_common_data *data, int *val)
+{
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(data->regmap, SX9360_REG_PROX_CTRL4, &regval);
+	if (ret)
+		return ret;
+
+	regval = FIELD_GET(SX9360_REG_PROX_CTRL4_CLOSE_DEBOUNCE_MASK, regval);
+	if (regval)
+		*val = 1 << regval;
+	else
+		*val = 0;
+
+	return IIO_VAL_INT;
+}
+
+static int sx9360_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 sx9360_read_thresh(data, val);
+	case IIO_EV_INFO_PERIOD:
+		switch (dir) {
+		case IIO_EV_DIR_RISING:
+			return sx9360_read_far_debounce(data, val);
+		case IIO_EV_DIR_FALLING:
+			return sx9360_read_close_debounce(data, val);
+		default:
+			return -EINVAL;
+		}
+	case IIO_EV_INFO_HYSTERESIS:
+		return sx9360_read_hysteresis(data, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int sx9360_write_thresh(struct sx_common_data *data, int _val)
+{
+	unsigned int val = _val;
+	int ret;
+
+	if (val >= 1)
+		val = int_sqrt(2 * val);
+
+	if (val > 0xff)
+		return -EINVAL;
+
+	mutex_lock(&data->mutex);
+	ret = regmap_write(data->regmap, SX9360_REG_PROX_CTRL5, val);
+	mutex_unlock(&data->mutex);
+
+	return ret;
+}
+
+static int sx9360_write_hysteresis(struct sx_common_data *data, int _val)
+{
+	unsigned int hyst, val = _val;
+	int ret, pthresh;
+
+	ret = sx9360_read_thresh(data, &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(SX9360_REG_PROX_CTRL4_HYST_MASK, hyst);
+	mutex_lock(&data->mutex);
+	ret = regmap_update_bits(data->regmap, SX9360_REG_PROX_CTRL4,
+				 SX9360_REG_PROX_CTRL4_HYST_MASK, hyst);
+	mutex_unlock(&data->mutex);
+
+	return ret;
+}
+
+static int sx9360_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(SX9360_REG_PROX_CTRL4_FAR_DEBOUNCE_MASK, val))
+		return -EINVAL;
+
+	regval = FIELD_PREP(SX9360_REG_PROX_CTRL4_FAR_DEBOUNCE_MASK, val);
+
+	mutex_lock(&data->mutex);
+	ret = regmap_update_bits(data->regmap, SX9360_REG_PROX_CTRL4,
+				 SX9360_REG_PROX_CTRL4_FAR_DEBOUNCE_MASK,
+				 regval);
+	mutex_unlock(&data->mutex);
+
+	return ret;
+}
+
+static int sx9360_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(SX9360_REG_PROX_CTRL4_CLOSE_DEBOUNCE_MASK, val))
+		return -EINVAL;
+
+	regval = FIELD_PREP(SX9360_REG_PROX_CTRL4_CLOSE_DEBOUNCE_MASK, val);
+
+	mutex_lock(&data->mutex);
+	ret = regmap_update_bits(data->regmap, SX9360_REG_PROX_CTRL4,
+				 SX9360_REG_PROX_CTRL4_CLOSE_DEBOUNCE_MASK,
+				 regval);
+	mutex_unlock(&data->mutex);
+
+	return ret;
+}
+
+static int sx9360_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 sx9360_write_thresh(data, val);
+	case IIO_EV_INFO_PERIOD:
+		switch (dir) {
+		case IIO_EV_DIR_RISING:
+			return sx9360_write_far_debounce(data, val);
+		case IIO_EV_DIR_FALLING:
+			return sx9360_write_close_debounce(data, val);
+		default:
+			return -EINVAL;
+		}
+	case IIO_EV_INFO_HYSTERESIS:
+		return sx9360_write_hysteresis(data, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int sx9360_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 = SX9360_REG_PROX_CTRL0_PHR + chan->channel;
+	gain = FIELD_PREP(SX9360_REG_PROX_CTRL0_GAIN_MASK, gain);
+
+	mutex_lock(&data->mutex);
+	ret = regmap_update_bits(data->regmap, reg,
+				 SX9360_REG_PROX_CTRL0_GAIN_MASK,
+				 gain);
+	mutex_unlock(&data->mutex);
+
+	return ret;
+}
+
+static int sx9360_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 sx9360_set_samp_freq(data, val, val2);
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		return sx9360_write_gain(data, chan, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+/* Activate all channels and perform an initial compensation. */
+static int sx9360_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, SX9360_REG_STAT,
+				 SX9360_REG_STAT_COMPSTAT_MASK,
+				 SX9360_REG_STAT_COMPSTAT_MASK);
+	if (ret)
+		return ret;
+
+	ret = regmap_read_poll_timeout(data->regmap, SX9360_REG_STAT, val,
+				       !(val & SX9360_REG_STAT_COMPSTAT_MASK),
+				       20000, 2000000);
+	if (ret == -ETIMEDOUT)
+		dev_err(&data->client->dev,
+			"initial compensation timed out: 0x%02x\n",
+			val);
+	return ret;
+}
+
+static int sx9360_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 = "sx9360";
+	return 0;
+}
+
+static const struct sx_common_chip_info sx9360_chip_info = {
+	.reg_stat = SX9360_REG_STAT,
+	.reg_irq_msk = SX9360_REG_IRQ_MSK,
+	.reg_enable_chan = SX9360_REG_GNRL_CTRL0,
+	.reg_reset = SX9360_REG_RESET,
+
+	.mask_enable_chan = SX9360_REG_GNRL_CTRL0_PHEN_MASK,
+	.stat_offset = 3,
+	.num_channels = SX9360_NUM_CHANNELS,
+
+	.ops = {
+		.read_prox_data = sx9360_read_prox_data,
+		.check_whoami = sx9360_check_whoami,
+		.init_compensation = sx9360_init_compensation,
+		.wait_for_sample = sx9360_wait_for_sample,
+	},
+
+	.iio_channels = sx9360_channels,
+	.num_iio_channels = ARRAY_SIZE(sx9360_channels),
+	.iio_info =  {
+		.read_raw = sx9360_read_raw,
+		.read_avail = sx9360_read_avail,
+		.read_label = sx9360_read_label,
+		.read_event_value = sx9360_read_event_val,
+		.write_event_value = sx9360_write_event_val,
+		.write_raw = sx9360_write_raw,
+		.read_event_config = sx_common_read_event_config,
+		.write_event_config = sx_common_write_event_config,
+	},
+};
+
+static int sx9360_probe(struct i2c_client *client)
+{
+	return sx_common_probe(client, &sx9360_chip_info, &sx9360_regmap_config);
+}
+
+static int __maybe_unused sx9360_suspend(struct device *dev)
+{
+	struct sx_common_data *data = iio_priv(dev_get_drvdata(dev));
+	unsigned int regval;
+	int ret;
+
+	disable_irq_nosync(data->client->irq);
+
+	mutex_lock(&data->mutex);
+	ret = regmap_read(data->regmap, SX9360_REG_GNRL_CTRL0, &regval);
+
+	data->suspend_ctrl =
+		FIELD_GET(SX9360_REG_GNRL_CTRL0_PHEN_MASK, regval);
+
+	if (ret < 0)
+		goto out;
+
+	/* Disable all phases, send the device to sleep. */
+	ret = regmap_write(data->regmap, SX9360_REG_GNRL_CTRL0, 0);
+
+out:
+	mutex_unlock(&data->mutex);
+	return ret;
+}
+
+static int __maybe_unused sx9360_resume(struct device *dev)
+{
+	struct sx_common_data *data = iio_priv(dev_get_drvdata(dev));
+	int ret;
+
+	mutex_lock(&data->mutex);
+	ret = regmap_update_bits(data->regmap, SX9360_REG_GNRL_CTRL0,
+				 SX9360_REG_GNRL_CTRL0_PHEN_MASK,
+				 data->suspend_ctrl);
+	mutex_unlock(&data->mutex);
+	if (ret)
+		return ret;
+
+	enable_irq(data->client->irq);
+	return 0;
+}
+
+static const struct dev_pm_ops sx9360_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(sx9360_suspend, sx9360_resume)
+};
+
+static const struct acpi_device_id sx9360_acpi_match[] = {
+	{ "STH9360", SX9360_WHOAMI_VALUE},
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, sx9360_acpi_match);
+
+static const struct of_device_id sx9360_of_match[] = {
+	{ .compatible = "semtech,sx9360", (void *)SX9360_WHOAMI_VALUE},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, sx9360_of_match);
+
+static const struct i2c_device_id sx9360_id[] = {
+	{"sx9360", SX9360_WHOAMI_VALUE},
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, sx9360_id);
+
+static struct i2c_driver sx9360_driver = {
+	.driver = {
+		.name	= "sx9360",
+		.acpi_match_table = sx9360_acpi_match,
+		.of_match_table = sx9360_of_match,
+		.pm = &sx9360_pm_ops,
+
+		/*
+		 * Lots of i2c transfers in probe + over 200 ms waiting in
+		 * sx9360_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	= sx9360_probe,
+	.id_table	= sx9360_id,
+};
+module_i2c_driver(sx9360_driver);
+
+MODULE_AUTHOR("Gwendal Grignou <gwendal@chromium.org>");
+MODULE_DESCRIPTION("Driver for Semtech SX9360 proximity sensor");
+MODULE_LICENSE("GPL v2");
-- 
2.34.1.173.g76aa8bc2d0-goog

Re: [PATCH v4 1/3] iio: proximity: Add sx9360 support

[Jonathan Cameron]

On Fri, 17 Dec 2021 16:27:03 -0800
Gwendal Grignou <gwendal@chromium.org> wrote:

> A simplified version of SX9324, it only have one pin and
> 2 phases (aka channels).
> Only one event is presented.
> 
> Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
> Reviewed-by: Stephen Boyd <swboyd@chromium.org>
> ---
> Changes since v3:
> - Remove "reference" as a new modifier: it is not needed, indexed
>   channels and labels are used instead.
> - Use dev_get_drvdata to access iio device structure.
> - Use already calculated local variable
> - Use default: clause to return when possible.
> 
> Changes since v2:
> - Fix issues reported during sx9324 driver review:
>   - fix include with iwyu
>   - Remove call to ACPI_PTR to prevent unused variable warning.
> - Fix panic when setting frequency to 0.
> - Add offset to decipher interrupt register
> - Fix default register value.
> 
> Changes since v1:
> - Remove SX9360_DRIVER_NAME
> - Simplify whoami function
> - Define WHOAMI register value internally.
> - Handle negative values when setting sysfs parameters.
> 
>  drivers/iio/proximity/Kconfig  |  14 +
>  drivers/iio/proximity/Makefile |   1 +
>  drivers/iio/proximity/sx9360.c | 816 +++++++++++++++++++++++++++++++++
>  3 files changed, 831 insertions(+)
>  create mode 100644 drivers/iio/proximity/sx9360.c
> 
Hi Gwendal,

A few trivial things that I'd just have tidied up whilst applying except
that this is dependent on the earlier series anyway so I can't apply yet.

> +
> +/*
> + * 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.
> + *
> + * The frequency control register holds the period, with a ~2ms increment.
> + * Therefore the smallest frequency is 4MHz / (2047 * 8192),
> + * The fastest is 4MHz / 8192.
> + * The interval is not linear, but given there is 2047 possible value,
> + * Returns the fake increment of (Max-Min)/2047
> + *

Trivial, but this blank line doesn't add anything so please remove.

> + */
> +static const struct {
> +	int val;
> +	int val2;
> +} sx9360_samp_freq_interval[] = {
> +	{0, 281250},  /* 4MHz / (8192 * 2047) */
> +	{0, 281250},
> +	{448, 281250},  /* 4MHz / 8192 */
> +};
> +
...


> +static int sx9360_read_label(struct iio_dev *iio_dev, const struct iio_chan_spec *chan,
> +			     char *label)
> +{
> +	return snprintf(label, PAGE_SIZE, "%s\n", sx9360_channel_labels[chan->channel]);

Trivial but preference for sysfs_emit()
(Andy noted this for the other driver in a more complex case so I did a quick
search for repeats)

> +}
> +


...

> +
> +static const struct dev_pm_ops sx9360_pm_ops = {
> +	SET_SYSTEM_SLEEP_PM_OPS(sx9360_suspend, sx9360_resume)
> +};

static SIMPLE_DEV_PM_OPS(sx9360_pm_ops, sx9360_suspend, sx9360_resume);

Re: [PATCH v4 1/3] iio: proximity: Add sx9360 support

[Gwendal Grignou]

On Tue, Dec 21, 2021 at 4:54 AM Jonathan Cameron <jic23@kernel.org> wrote:
>
> On Fri, 17 Dec 2021 16:27:03 -0800
> Gwendal Grignou <gwendal@chromium.org> wrote:
>
> > A simplified version of SX9324, it only have one pin and
> > 2 phases (aka channels).
> > Only one event is presented.
> >
> > Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
> > Reviewed-by: Stephen Boyd <swboyd@chromium.org>
> > ---
> > Changes since v3:
> > - Remove "reference" as a new modifier: it is not needed, indexed
> >   channels and labels are used instead.
> > - Use dev_get_drvdata to access iio device structure.
> > - Use already calculated local variable
> > - Use default: clause to return when possible.
> >
> > Changes since v2:
> > - Fix issues reported during sx9324 driver review:
> >   - fix include with iwyu
> >   - Remove call to ACPI_PTR to prevent unused variable warning.
> > - Fix panic when setting frequency to 0.
> > - Add offset to decipher interrupt register
> > - Fix default register value.
> >
> > Changes since v1:
> > - Remove SX9360_DRIVER_NAME
> > - Simplify whoami function
> > - Define WHOAMI register value internally.
> > - Handle negative values when setting sysfs parameters.
> >
> >  drivers/iio/proximity/Kconfig  |  14 +
> >  drivers/iio/proximity/Makefile |   1 +
> >  drivers/iio/proximity/sx9360.c | 816 +++++++++++++++++++++++++++++++++
> >  3 files changed, 831 insertions(+)
> >  create mode 100644 drivers/iio/proximity/sx9360.c
> >
> Hi Gwendal,
>
> A few trivial things that I'd just have tidied up whilst applying except
> that this is dependent on the earlier series anyway so I can't apply yet.
>
> > +
> > +/*
> > + * 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.
> > + *
> > + * The frequency control register holds the period, with a ~2ms increment.
> > + * Therefore the smallest frequency is 4MHz / (2047 * 8192),
> > + * The fastest is 4MHz / 8192.
> > + * The interval is not linear, but given there is 2047 possible value,
> > + * Returns the fake increment of (Max-Min)/2047
> > + *
>
> Trivial, but this blank line doesn't add anything so please remove.
Remove some in sx_common.h as well.
>
> > + */
> > +static const struct {
> > +     int val;
> > +     int val2;
> > +} sx9360_samp_freq_interval[] = {
> > +     {0, 281250},  /* 4MHz / (8192 * 2047) */
> > +     {0, 281250},
> > +     {448, 281250},  /* 4MHz / 8192 */
> > +};
> > +
> ...
>
>
> > +static int sx9360_read_label(struct iio_dev *iio_dev, const struct iio_chan_spec *chan,
> > +                          char *label)
> > +{
> > +     return snprintf(label, PAGE_SIZE, "%s\n", sx9360_channel_labels[chan->channel]);
>
> Trivial but preference for sysfs_emit()
> (Andy noted this for the other driver in a more complex case so I did a quick
> search for repeats)
Fixed in other patches as well.
>
> > +}
> > +
>
>
> ...
>
> > +
> > +static const struct dev_pm_ops sx9360_pm_ops = {
> > +     SET_SYSTEM_SLEEP_PM_OPS(sx9360_suspend, sx9360_resume)
> > +};
>
> static SIMPLE_DEV_PM_OPS(sx9360_pm_ops, sx9360_suspend, sx9360_resume);
Fix in sx9310/24 and 60 driver as well.
>
>

[PATCH v4 2/3] dt-bindings: iio: Add sx9360 binding

[Gwendal Grignou]

Add binding to configure Semtech sx9360 sensor.
It is a simpler version of sx9324.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
---
No Changes since v3.
Changes since v2:
- Use const instead of single enum.
- Use proper syntax for maximum/minimum
- Fix spelling errors.

Changes since v1:
- Fix cut and paste error.
- Add . at end of sentence.

 .../iio/proximity/semtech,sx9360.yaml         | 89 +++++++++++++++++++
 1 file changed, 89 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/proximity/semtech,sx9360.yaml

diff --git a/Documentation/devicetree/bindings/iio/proximity/semtech,sx9360.yaml b/Documentation/devicetree/bindings/iio/proximity/semtech,sx9360.yaml
new file mode 100644
index 00000000000000..63e1a1fd00d4ca
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/proximity/semtech,sx9360.yaml
@@ -0,0 +1,89 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/proximity/semtech,sx9360.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Semtech's SX9360 capacitive proximity sensor
+
+maintainers:
+  - Gwendal Grignou <gwendal@chromium.org>
+  - Daniel Campello <campello@chromium.org>
+
+description: |
+  Semtech's SX9360 proximity sensor.
+
+properties:
+  compatible:
+    const: semtech,sx9360
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    description:
+      Generated by device to announce preceding read request has finished
+      and data is available or that a close/far proximity event has happened.
+    maxItems: 1
+
+  vdd-supply:
+    description: Main power supply
+
+  svdd-supply:
+    description: Host interface power supply
+
+  "#io-channel-cells":
+    const: 1
+
+  semtech,resolution:
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    enum: [8, 16, 32, 64, 128, 256, 512, 1024]
+    description:
+      Capacitance measurement resolution. For both phases, "reference" and
+      "measurement". Higher the number, higher the resolution.
+    default: 128
+
+  semtech,proxraw-strength:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 0
+    maximum: 7
+    default: 1
+    description:
+      PROXRAW filter strength for both phases. A value of 0 represents off,
+      and other values represent 1-1/2^N.
+
+  semtech,avg-pos-strength:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [0, 16, 64, 128, 256, 512, 1024, 4294967295]
+    default: 16
+    description: |
+      Average positive filter strength. A value of 0 represents off and
+      UINT_MAX (4294967295) represents infinite. Other values
+      represent 1-1/N.
+
+required:
+  - compatible
+  - reg
+  - "#io-channel-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+      proximity@28 {
+        compatible = "semtech,sx9360";
+        reg = <0x28>;
+        interrupt-parent = <&pio>;
+        interrupts = <5 IRQ_TYPE_LEVEL_LOW 5>;
+        vdd-supply = <&pp3300_a>;
+        svdd-supply = <&pp1800_prox>;
+        #io-channel-cells = <1>;
+        semtech,resolution = <256>;
+        semtech,proxraw-strength = <2>;
+        semtech,avg-pos-strength = <64>;
+      };
+    };
-- 
2.34.1.173.g76aa8bc2d0-goog

[PATCH v4 3/3] iio: sx9360: Add dt-binding support

[Gwendal Grignou]

Add support to configure sx9360 from dt-binding, to match device
hardware setup.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
---
Changes since v3:
- Concatenate 2 lines.

Changes since v2:
- Add include when needed.
- Move default register constant to main patch.

No changes in v2.

 drivers/iio/proximity/sx9360.c | 84 ++++++++++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)

diff --git a/drivers/iio/proximity/sx9360.c b/drivers/iio/proximity/sx9360.c
index 75788bbf70efac..c32d4f8b162fd4 100644
--- a/drivers/iio/proximity/sx9360.c
+++ b/drivers/iio/proximity/sx9360.c
@@ -18,6 +18,7 @@
 #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>
@@ -64,6 +65,7 @@
 #define SX9360_REG_PROX_CTRL0_PHM	0x41
 #define SX9360_REG_PROX_CTRL0_GAIN_MASK	GENMASK(5, 3)
 #define SX9360_REG_PROX_CTRL0_GAIN_1		0x80
+#define SX9360_REG_PROX_CTRL0_RAWFILT_MASK	GENMASK(2, 0)
 #define SX9360_REG_PROX_CTRL0_RAWFILT_1P50	0x01
 #define SX9360_REG_PROX_CTRL1		0x42
 #define SX9360_REG_PROX_CTRL1_AVGNEG_THRESH_MASK	GENMASK(5, 3)
@@ -658,6 +660,41 @@ static int sx9360_write_raw(struct iio_dev *indio_dev,
 	}
 }
 
+static const struct sx_common_reg_default sx9360_default_regs[] = {
+	{ SX9360_REG_IRQ_MSK, 0x00 },
+	{ SX9360_REG_IRQ_CFG, 0x00 },
+	/*
+	 * The lower 2 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.
+	 */
+	{ SX9360_REG_GNRL_CTRL0, 0x00 },
+	{ SX9360_REG_GNRL_CTRL1, 0x00 },
+	{ SX9360_REG_GNRL_CTRL2, SX9360_REG_GNRL_CTRL2_PERIOD_102MS },
+
+	{ SX9360_REG_AFE_CTRL1, 0x00 },
+	{ SX9360_REG_AFE_PARAM0_PHR, SX9360_REG_AFE_PARAM0_RSVD |
+		SX9360_REG_AFE_PARAM0_RESOLUTION_128 },
+	{ SX9360_REG_AFE_PARAM1_PHR, SX9360_REG_AFE_PARAM1_AGAIN_PHM_6PF |
+		SX9360_REG_AFE_PARAM1_FREQ_83_33HZ },
+	{ SX9360_REG_AFE_PARAM0_PHM, SX9360_REG_AFE_PARAM0_RSVD |
+		SX9360_REG_AFE_PARAM0_RESOLUTION_128 },
+	{ SX9360_REG_AFE_PARAM1_PHM, SX9360_REG_AFE_PARAM1_AGAIN_PHM_6PF |
+		SX9360_REG_AFE_PARAM1_FREQ_83_33HZ },
+
+	{ SX9360_REG_PROX_CTRL0_PHR, SX9360_REG_PROX_CTRL0_GAIN_1 |
+		SX9360_REG_PROX_CTRL0_RAWFILT_1P50 },
+	{ SX9360_REG_PROX_CTRL0_PHM, SX9360_REG_PROX_CTRL0_GAIN_1 |
+		SX9360_REG_PROX_CTRL0_RAWFILT_1P50 },
+	{ SX9360_REG_PROX_CTRL1, SX9360_REG_PROX_CTRL1_AVGNEG_THRESH_16K },
+	{ SX9360_REG_PROX_CTRL2, SX9360_REG_PROX_CTRL2_AVGDEB_2SAMPLES |
+		SX9360_REG_PROX_CTRL2_AVGPOS_THRESH_16K },
+	{ SX9360_REG_PROX_CTRL3, SX9360_REG_PROX_CTRL3_AVGNEG_FILT_2 |
+		SX9360_REG_PROX_CTRL3_AVGPOS_FILT_256 },
+	{ SX9360_REG_PROX_CTRL4, 0x00 },
+	{ SX9360_REG_PROX_CTRL5, SX9360_REG_PROX_CTRL5_PROXTHRESH_32 },
+};
+
 /* Activate all channels and perform an initial compensation. */
 static int sx9360_init_compensation(struct iio_dev *indio_dev)
 {
@@ -682,6 +719,51 @@ static int sx9360_init_compensation(struct iio_dev *indio_dev)
 	return ret;
 }
 
+static const struct sx_common_reg_default *
+sx9360_get_default_reg(struct device *dev, int idx,
+		       struct sx_common_reg_default *reg_def)
+{
+	u32 raw = 0, pos = 0;
+	int ret;
+
+	memcpy(reg_def, &sx9360_default_regs[idx], sizeof(*reg_def));
+	switch (reg_def->reg) {
+	case SX9360_REG_AFE_PARAM0_PHR:
+	case SX9360_REG_AFE_PARAM0_PHM:
+		ret = device_property_read_u32(dev, "semtech,resolution", &raw);
+		if (ret)
+			break;
+
+		raw = ilog2(raw) - 3;
+
+		reg_def->def &= ~SX9360_REG_AFE_PARAM0_RESOLUTION_MASK;
+		reg_def->def |= FIELD_PREP(SX9360_REG_AFE_PARAM0_RESOLUTION_MASK, raw);
+		break;
+	case SX9360_REG_PROX_CTRL0_PHR:
+	case SX9360_REG_PROX_CTRL0_PHM:
+		ret = device_property_read_u32(dev, "semtech,proxraw-strength", &raw);
+		if (ret)
+			break;
+
+		reg_def->def &= ~SX9360_REG_PROX_CTRL0_RAWFILT_MASK;
+		reg_def->def |= FIELD_PREP(SX9360_REG_PROX_CTRL0_RAWFILT_MASK, raw);
+		break;
+	case SX9360_REG_PROX_CTRL3:
+		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 */
+		raw = clamp(ilog2(pos), 3, 11) - (pos >= 32 ? 4 : 3);
+		reg_def->def &= ~SX9360_REG_PROX_CTRL3_AVGPOS_FILT_MASK;
+		reg_def->def |= FIELD_PREP(SX9360_REG_PROX_CTRL3_AVGPOS_FILT_MASK, raw);
+		break;
+	}
+
+	return reg_def;
+}
+
 static int sx9360_check_whoami(struct device *dev, struct iio_dev *indio_dev)
 {
 	/*
@@ -701,12 +783,14 @@ static const struct sx_common_chip_info sx9360_chip_info = {
 	.mask_enable_chan = SX9360_REG_GNRL_CTRL0_PHEN_MASK,
 	.stat_offset = 3,
 	.num_channels = SX9360_NUM_CHANNELS,
+	.num_default_regs = ARRAY_SIZE(sx9360_default_regs),
 
 	.ops = {
 		.read_prox_data = sx9360_read_prox_data,
 		.check_whoami = sx9360_check_whoami,
 		.init_compensation = sx9360_init_compensation,
 		.wait_for_sample = sx9360_wait_for_sample,
+		.get_default_reg = sx9360_get_default_reg,
 	},
 
 	.iio_channels = sx9360_channels,
-- 
2.34.1.173.g76aa8bc2d0-goog