[PATCH 2/2] iio: Add driver for Murata IRS-D200

[Waqar Hameed]

Murata IRS-D200 is a PIR sensor for human detection. It has support for
raw data measurements and detection event notification.

Add a driver with support for triggered buffer and events. Map the
various settings to the `iio` framework, e.g. threshold values, sampling
frequency, filter frequencies etc.

Signed-off-by: Waqar Hameed <waqar.hameed@xxxxxxxx>
---
 drivers/iio/proximity/Kconfig   |   12 +
 drivers/iio/proximity/Makefile  |    1 +
 drivers/iio/proximity/irsd200.c | 1051 +++++++++++++++++++++++++++++++
 3 files changed, 1064 insertions(+)
 create mode 100644 drivers/iio/proximity/irsd200.c

diff --git a/drivers/iio/proximity/Kconfig b/drivers/iio/proximity/Kconfig
index 0e5c17530b8b..2ca3b0bc5eba 100644
--- a/drivers/iio/proximity/Kconfig
+++ b/drivers/iio/proximity/Kconfig
@@ -32,6 +32,18 @@ config CROS_EC_MKBP_PROXIMITY
 	  To compile this driver as a module, choose M here: the
 	  module will be called cros_ec_mkbp_proximity.
 
+config IRSD200
+	tristate "Murata IRS-D200 PIR sensor"
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	select REGMAP_I2C
+	depends on I2C
+	help
+	  Say Y here to build a driver for the Murata IRS-D200 PIR sensor.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called irsd200.
+
 config ISL29501
 	tristate "Intersil ISL29501 Time Of Flight sensor"
 	depends on I2C
diff --git a/drivers/iio/proximity/Makefile b/drivers/iio/proximity/Makefile
index cc838bb5408a..f36598380446 100644
--- a/drivers/iio/proximity/Makefile
+++ b/drivers/iio/proximity/Makefile
@@ -6,6 +6,7 @@
 # When adding new entries keep the list in alphabetical order
 obj-$(CONFIG_AS3935)		+= as3935.o
 obj-$(CONFIG_CROS_EC_MKBP_PROXIMITY) += cros_ec_mkbp_proximity.o
+obj-$(CONFIG_IRSD200)		+= irsd200.o
 obj-$(CONFIG_ISL29501)		+= isl29501.o
 obj-$(CONFIG_LIDAR_LITE_V2)	+= pulsedlight-lidar-lite-v2.o
 obj-$(CONFIG_MB1232)		+= mb1232.o
diff --git a/drivers/iio/proximity/irsd200.c b/drivers/iio/proximity/irsd200.c
new file mode 100644
index 000000000000..699801d60295
--- /dev/null
+++ b/drivers/iio/proximity/irsd200.c
@@ -0,0 +1,1051 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for Murata IRS-D200 PIR sensor.
+ *
+ * Copyright (C) 2023 Axis Communications AB
+ */
+
+#include <linux/gpio.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/events.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/types.h>
+
+#define IRS_DRV_NAME "irsd200"
+
+/* Registers. */
+#define IRS_REG_OP		0x00	/* Operation mode. */
+#define IRS_REG_DATA_LO		0x02	/* Sensor data LSB. */
+#define IRS_REG_DATA_HI		0x03	/* Sensor data MSB. */
+#define IRS_REG_STATUS		0x04	/* Interrupt status. */
+#define IRS_REG_COUNT		0x05	/* Count of exceeding threshold. */
+#define IRS_REG_DATA_RATE	0x06	/* Output data rate. */
+#define IRS_REG_FILTER		0x07	/* High-pass and low-pass filter. */
+#define IRS_REG_INTR		0x09	/* Interrupt mode. */
+#define IRS_REG_NR_COUNT	0x0a	/* Number of counts before interrupt. */
+#define IRS_REG_THR_HI		0x0b	/* Upper threshold. */
+#define IRS_REG_THR_LO		0x0c	/* Lower threshold. */
+#define IRS_REG_TIMER_LO	0x0d	/* Timer setting LSB. */
+#define IRS_REG_TIMER_HI	0x0e	/* Timer setting MSB. */
+
+/* Interrupt status bits. */
+#define IRS_INTR_DATA		0	/* Data update. */
+#define IRS_INTR_TIMER		1	/* Timer expiration. */
+#define IRS_INTR_COUNT_THR_AND	2	/* Count "AND" threshold. */
+#define IRS_INTR_COUNT_THR_OR	3	/* Count "OR" threshold. */
+
+/*
+ * Quantization scale value for threshold. Used for conversion from/to register
+ * value.
+ */
+#define IRS_THR_QUANT_SCALE	128
+
+/*
+ * The upper 4 bits in register IRS_REG_COUNT value is the upper count value
+ * (exceeding upper threshold value). The lower 4 is the lower count value
+ * (exceeding lower threshold value).
+ */
+#define IRS_UPPER_COUNT(count)	(count >> 4)
+#define IRS_LOWER_COUNT(count)	(count & GENMASK(3, 0))
+
+/* Index corresponds to the value of IRS_REG_DATA_RATE register. */
+static const int irsd200_data_rates[2] = {
+	50,
+	100,
+};
+
+/* Index corresponds to the (field) value of IRS_REG_FILTER register. */
+static const unsigned int irsd200_lp_filter_freq[2] = {
+	10,
+	7,
+};
+
+/*
+ * Index corresponds to the (field) value of IRS_REG_FILTER register. Contains
+ * only the fractional part (since the integer part is 0, e.g the first value
+ * corresponds to 0.3 Hz).
+ */
+static const unsigned int irsd200_hp_filter_freq[2] = {
+	3,
+	5,
+};
+
+/* Register fields. */
+enum irsd200_regfield {
+	/* Data interrupt. */
+	IRS_REGF_INTR_DATA,
+	/* Timer interrupt. */
+	IRS_REGF_INTR_TIMER,
+	/* AND count threshold interrupt. */
+	IRS_REGF_INTR_COUNT_THR_AND,
+	/* OR count threshold interrupt. */
+	IRS_REGF_INTR_COUNT_THR_OR,
+
+	/* Low-pass filter frequency. */
+	IRS_REGF_LP_FILTER,
+	/* High-pass filter frequency. */
+	IRS_REGF_HP_FILTER,
+
+	/* Sentinel value. */
+	IRS_REGF_MAX
+};
+
+static const struct reg_field irsd200_regfields[] = {
+	[IRS_REGF_INTR_DATA] =
+		REG_FIELD(IRS_REG_INTR, IRS_INTR_DATA, IRS_INTR_DATA),
+	[IRS_REGF_INTR_TIMER] =
+		REG_FIELD(IRS_REG_INTR, IRS_INTR_TIMER, IRS_INTR_TIMER),
+	[IRS_REGF_INTR_COUNT_THR_AND] = REG_FIELD(
+		IRS_REG_INTR, IRS_INTR_COUNT_THR_AND, IRS_INTR_COUNT_THR_AND),
+	[IRS_REGF_INTR_COUNT_THR_OR] = REG_FIELD(
+		IRS_REG_INTR, IRS_INTR_COUNT_THR_OR, IRS_INTR_COUNT_THR_OR),
+
+	[IRS_REGF_LP_FILTER] = REG_FIELD(IRS_REG_FILTER, 1, 1),
+	[IRS_REGF_HP_FILTER] = REG_FIELD(IRS_REG_FILTER, 0, 0),
+};
+
+static const struct regmap_config irsd200_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = IRS_REG_TIMER_HI,
+};
+
+struct irsd200_data {
+	struct regmap *regmap;
+	struct regmap_field *regfields[IRS_REGF_MAX];
+	struct device *dev;
+};
+
+static int irsd200_setup(struct irsd200_data *data)
+{
+	unsigned int val;
+	int ret;
+
+	/* Disable all interrupt sources. */
+	ret = regmap_write(data->regmap, IRS_REG_INTR, 0);
+	if (ret) {
+		dev_err(data->dev, "Could not set interrupt sources (%d)\n",
+			ret);
+		return ret;
+	}
+
+	/* Set operation to active. */
+	ret = regmap_write(data->regmap, IRS_REG_OP, 0x00);
+	if (ret) {
+		dev_err(data->dev, "Could not set operation mode (%d)\n", ret);
+		return ret;
+	}
+
+	/* Clear threshold count. */
+	ret = regmap_read(data->regmap, IRS_REG_COUNT, &val);
+	if (ret) {
+		dev_err(data->dev, "Could not clear threshold count (%d)\n",
+			ret);
+		return ret;
+	}
+
+	/* Clear status. */
+	ret = regmap_write(data->regmap, IRS_REG_STATUS, 0x0f);
+	if (ret) {
+		dev_err(data->dev, "Could not clear status (%d)\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int irsd200_read_threshold(struct irsd200_data *data,
+				  enum iio_event_direction dir, int *val)
+{
+	unsigned int regval;
+	unsigned int reg;
+	int scale;
+	int ret;
+
+	/* Set quantization scale. */
+	if (dir == IIO_EV_DIR_RISING) {
+		scale = IRS_THR_QUANT_SCALE;
+		reg = IRS_REG_THR_HI;
+	} else if (dir == IIO_EV_DIR_FALLING) {
+		scale = -IRS_THR_QUANT_SCALE;
+		reg = IRS_REG_THR_LO;
+	} else {
+		return -EINVAL;
+	}
+
+	ret = regmap_read(data->regmap, reg, &regval);
+	if (ret < 0) {
+		dev_err(data->dev, "Could not read threshold (%d)\n", ret);
+		return ret;
+	}
+
+	*val = ((int)regval) * scale;
+
+	return 0;
+}
+
+static int irsd200_write_threshold(struct irsd200_data *data,
+				   enum iio_event_direction dir, int val)
+{
+	unsigned int regval;
+	unsigned int reg;
+	int scale;
+	int ret;
+
+	/* Set quantization scale. */
+	if (dir == IIO_EV_DIR_RISING) {
+		if (val < 0)
+			return -ERANGE;
+
+		scale = IRS_THR_QUANT_SCALE;
+		reg = IRS_REG_THR_HI;
+	} else if (dir == IIO_EV_DIR_FALLING) {
+		if (val > 0)
+			return -ERANGE;
+
+		scale = -IRS_THR_QUANT_SCALE;
+		reg = IRS_REG_THR_LO;
+	} else {
+		return -EINVAL;
+	}
+
+	regval = val / scale;
+
+	if (regval >= BIT(8))
+		return -ERANGE;
+
+	ret = regmap_write(data->regmap, reg, regval);
+	if (ret < 0) {
+		dev_err(data->dev, "Could not write threshold (%d)\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int irsd200_read_data(struct irsd200_data *data, s16 *val)
+{
+	unsigned int tmpval;
+	int ret;
+
+	ret = regmap_read(data->regmap, IRS_REG_DATA_HI, &tmpval);
+	if (ret < 0) {
+		dev_err(data->dev, "Could not read hi data (%d)\n", ret);
+		return ret;
+	}
+
+	*val = (s16)(tmpval << 8);
+
+	ret = regmap_read(data->regmap, IRS_REG_DATA_LO, &tmpval);
+	if (ret < 0) {
+		dev_err(data->dev, "Could not read lo data (%d)\n", ret);
+		return ret;
+	}
+
+	*val |= tmpval;
+
+	return 0;
+}
+
+static int irsd200_read_data_rate(struct irsd200_data *data, int *val)
+{
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(data->regmap, IRS_REG_DATA_RATE, &regval);
+	if (ret < 0) {
+		dev_err(data->dev, "Could not read data rate (%d)\n", ret);
+		return ret;
+	}
+
+	if (regval >= ARRAY_SIZE(irsd200_data_rates))
+		return -ERANGE;
+
+	*val = irsd200_data_rates[regval];
+
+	return 0;
+}
+
+static int irsd200_write_data_rate(struct irsd200_data *data, int val)
+{
+	size_t idx;
+	int ret;
+
+	for (idx = 0; idx < ARRAY_SIZE(irsd200_data_rates); ++idx) {
+		if (irsd200_data_rates[idx] == val)
+			break;
+	}
+
+	if (idx == ARRAY_SIZE(irsd200_data_rates))
+		return -ERANGE;
+
+	ret = regmap_write(data->regmap, IRS_REG_DATA_RATE, idx);
+	if (ret < 0) {
+		dev_err(data->dev, "Could not write data rate (%d)\n", ret);
+		return ret;
+	}
+
+	/* Data sheet says the device needs 3 seconds of settling time. */
+	ssleep(3);
+
+	return 0;
+}
+
+static int irsd200_read_timer(struct irsd200_data *data, int *val, int *val2)
+{
+	unsigned int tmpval;
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(data->regmap, IRS_REG_TIMER_HI, &tmpval);
+	if (ret < 0) {
+		dev_err(data->dev, "Could not read hi timer (%d)\n", ret);
+		return ret;
+	}
+
+	/* Value is 10 bits. IRS_REG_TIMER_HI is the two MSBs. */
+	regval = tmpval << 8;
+
+	ret = regmap_read(data->regmap, IRS_REG_TIMER_LO, &tmpval);
+	if (ret < 0) {
+		dev_err(data->dev, "Could not read lo timer (%d)\n", ret);
+		return ret;
+	}
+
+	regval |= tmpval;
+
+	ret = irsd200_read_data_rate(data, val2);
+	if (ret < 0)
+		return ret;
+
+	*val = regval;
+
+	return 0;
+}
+
+static int irsd200_write_timer(struct irsd200_data *data, int val, int val2)
+{
+	unsigned int regval;
+	int data_rate;
+	int ret;
+
+	if (val < 0 || val2 < 0)
+		return -ERANGE;
+
+	ret = irsd200_read_data_rate(data, &data_rate);
+	if (ret < 0)
+		return ret;
+
+	/* Quantize from seconds. */
+	regval = val * data_rate + (val2 * data_rate) / 1000000;
+
+	/* Value is 10 bits. */
+	if (regval >= BIT(10))
+		return -ERANGE;
+
+	/* IRS_REG_TIMER_HI is the 2 MSBs. */
+	ret = regmap_write(data->regmap, IRS_REG_TIMER_HI, regval >> 8);
+	if (ret < 0) {
+		dev_err(data->dev, "Could not write hi timer (%d)\n", ret);
+		return ret;
+	}
+
+	/*
+	 * IRS_REG_TIMER_LO is the 8 LSBs. Since regmap_config is setup with
+	 * val_bits = 8, we don't have to mask the lower bits in regval when
+	 * writing.
+	 */
+	ret = regmap_write(data->regmap, IRS_REG_TIMER_LO, regval);
+	if (ret < 0) {
+		dev_err(data->dev, "Could not write lo timer (%d)\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int irsd200_read_nr_count(struct irsd200_data *data, int *val)
+{
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(data->regmap, IRS_REG_NR_COUNT, &regval);
+	if (ret < 0) {
+		dev_err(data->dev, "Could not read nr count (%d)\n", ret);
+		return ret;
+	}
+
+	*val = regval;
+
+	return 0;
+}
+
+static int irsd200_write_nr_count(struct irsd200_data *data, int val)
+{
+	unsigned int regval;
+	int ret;
+
+	/* A value of zero means that IRS_REG_STATUS is never set. */
+	if (val <= 0 || val >= BIT(3))
+		return -ERANGE;
+
+	regval = val;
+
+	if (regval >= 2) {
+		/*
+		 * According to the data sheet, timer must be also set in this
+		 * case (i.e. be non-zero). Check and enforce that.
+		 */
+		ret = irsd200_read_timer(data, &val, &val);
+		if (ret < 0)
+			return ret;
+
+		if (val == 0) {
+			dev_err(data->dev,
+				"Timer must be non-zero when nr count is %u\n",
+				regval);
+			return -EPERM;
+		}
+	}
+
+	ret = regmap_write(data->regmap, IRS_REG_NR_COUNT, regval);
+	if (ret < 0) {
+		dev_err(data->dev, "Could not write nr count (%d)\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int irsd200_read_lp_filter(struct irsd200_data *data, int *val)
+{
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_field_read(data->regfields[IRS_REGF_LP_FILTER], &regval);
+	if (ret < 0) {
+		dev_err(data->dev, "Could not read lp filter frequency (%d)\n",
+			ret);
+		return ret;
+	}
+
+	*val = irsd200_lp_filter_freq[regval];
+
+	return 0;
+}
+
+static int irsd200_write_lp_filter(struct irsd200_data *data, int val)
+{
+	size_t idx;
+	int ret;
+
+	for (idx = 0; idx < ARRAY_SIZE(irsd200_lp_filter_freq); ++idx) {
+		if (irsd200_lp_filter_freq[idx] == val)
+			break;
+	}
+
+	if (idx == ARRAY_SIZE(irsd200_lp_filter_freq))
+		return -ERANGE;
+
+	ret = regmap_field_write(data->regfields[IRS_REGF_LP_FILTER], idx);
+	if (ret < 0) {
+		dev_err(data->dev, "Could not write lp filter frequency (%d)\n",
+			ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int irsd200_read_hp_filter(struct irsd200_data *data, int *val,
+				  int *val2)
+{
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_field_read(data->regfields[IRS_REGF_HP_FILTER], &regval);
+	if (ret < 0) {
+		dev_err(data->dev, "Could not read hp filter frequency (%d)\n",
+			ret);
+		return ret;
+	}
+
+	*val = irsd200_hp_filter_freq[regval];
+	*val2 = 10;
+
+	return 0;
+}
+
+static int irsd200_write_hp_filter(struct irsd200_data *data, int val, int val2)
+{
+	size_t idx;
+	int ret;
+
+	/* Truncate fractional part to one digit. */
+	val2 /= 100000;
+
+	for (idx = 0; idx < ARRAY_SIZE(irsd200_hp_filter_freq); ++idx) {
+		if (irsd200_hp_filter_freq[idx] == val2)
+			break;
+	}
+
+	if (idx == ARRAY_SIZE(irsd200_hp_filter_freq) || val != 0)
+		return -ERANGE;
+
+	ret = regmap_field_write(data->regfields[IRS_REGF_HP_FILTER], idx);
+	if (ret < 0) {
+		dev_err(data->dev, "Could not write hp filter frequency (%d)\n",
+			ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int irsd200_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan, int *val,
+			    int *val2, long mask)
+{
+	struct irsd200_data *data = iio_priv(indio_dev);
+	int ret;
+	s16 buf;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = irsd200_read_data(data, &buf);
+		if (ret < 0)
+			return ret;
+
+		*val = buf;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		ret = irsd200_read_data_rate(data, val);
+		if (ret < 0)
+			return ret;
+
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int irsd200_read_avail(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan,
+			      const int **vals, int *type, int *length,
+			      long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*vals = irsd200_data_rates;
+		*type = IIO_VAL_INT;
+		*length = ARRAY_SIZE(irsd200_data_rates);
+		return IIO_AVAIL_LIST;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int irsd200_write_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan, int val,
+			     int val2, long mask)
+{
+	struct irsd200_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		ret = irsd200_write_data_rate(data, val);
+		return ret;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int irsd200_read_event(struct iio_dev *indio_dev,
+			      const struct iio_chan_spec *chan,
+			      enum iio_event_type type,
+			      enum iio_event_direction dir,
+			      enum iio_event_info info, int *val, int *val2)
+{
+	struct irsd200_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (info) {
+	case IIO_EV_INFO_VALUE:
+		ret = irsd200_read_threshold(data, dir, val);
+		if (ret < 0)
+			return ret;
+
+		return IIO_VAL_INT;
+	case IIO_EV_INFO_TIMEOUT:
+		ret = irsd200_read_timer(data, val, val2);
+		if (ret < 0)
+			return ret;
+
+		return IIO_VAL_FRACTIONAL;
+	case IIO_EV_INFO_PERIOD:
+		ret = irsd200_read_nr_count(data, val);
+		if (ret < 0)
+			return ret;
+
+		return IIO_VAL_INT;
+	case IIO_EV_INFO_LOW_PASS_FILTER_3DB:
+		ret = irsd200_read_lp_filter(data, val);
+		if (ret < 0)
+			return ret;
+
+		return IIO_VAL_INT;
+	case IIO_EV_INFO_HIGH_PASS_FILTER_3DB:
+		ret = irsd200_read_hp_filter(data, val, val2);
+		if (ret < 0)
+			return ret;
+
+		return IIO_VAL_FRACTIONAL;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int irsd200_write_event(struct iio_dev *indio_dev,
+			       const struct iio_chan_spec *chan,
+			       enum iio_event_type type,
+			       enum iio_event_direction dir,
+			       enum iio_event_info info, int val, int val2)
+{
+	struct irsd200_data *data = iio_priv(indio_dev);
+
+	switch (info) {
+	case IIO_EV_INFO_VALUE:
+		return irsd200_write_threshold(data, dir, val);
+	case IIO_EV_INFO_TIMEOUT:
+		return irsd200_write_timer(data, val, val2);
+	case IIO_EV_INFO_PERIOD:
+		return irsd200_write_nr_count(data, val);
+	case IIO_EV_INFO_LOW_PASS_FILTER_3DB:
+		return irsd200_write_lp_filter(data, val);
+	case IIO_EV_INFO_HIGH_PASS_FILTER_3DB:
+		return irsd200_write_hp_filter(data, val, val2);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int irsd200_read_event_config(struct iio_dev *indio_dev,
+				     const struct iio_chan_spec *chan,
+				     enum iio_event_type type,
+				     enum iio_event_direction dir)
+{
+	struct irsd200_data *data = iio_priv(indio_dev);
+	unsigned int val;
+	int ret;
+
+	switch (type) {
+	case IIO_EV_TYPE_THRESH:
+		if (dir != IIO_EV_DIR_RISING && dir != IIO_EV_DIR_FALLING)
+			return -EINVAL;
+
+		ret = regmap_field_read(
+			data->regfields[IRS_REGF_INTR_COUNT_THR_OR], &val);
+		if (ret < 0)
+			return ret;
+
+		return val;
+	case IIO_EV_TYPE_CHANGE:
+		ret = regmap_field_read(
+			data->regfields[IRS_REGF_INTR_TIMER], &val);
+		if (ret < 0)
+			return ret;
+
+		return val;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int irsd200_write_event_config(struct iio_dev *indio_dev,
+				      const struct iio_chan_spec *chan,
+				      enum iio_event_type type,
+				      enum iio_event_direction dir, int state)
+{
+	struct irsd200_data *data = iio_priv(indio_dev);
+	unsigned int val;
+	int ret;
+
+	switch (type) {
+	case IIO_EV_TYPE_THRESH:
+		/*
+		 * There is no way to tell the hardware to only signal for a
+		 * single direction. Let's just group IIO_EV_DIR_RISING and
+		 * IIO_EV_DIR_FALLING together instead of doing extra
+		 * (unnecessary) post-processing after an interrupt.
+		 */
+
+		/* Clear the count register (by reading from it). */
+		ret = regmap_read(data->regmap, IRS_REG_COUNT, &val);
+		if (ret < 0)
+			return ret;
+
+		val = !!state;
+		ret = regmap_field_write(
+			data->regfields[IRS_REGF_INTR_COUNT_THR_OR], val);
+		if (ret < 0)
+			return ret;
+
+		return val;
+	case IIO_EV_TYPE_CHANGE:
+		val = !!state;
+		ret = regmap_field_write(data->regfields[IRS_REGF_INTR_TIMER],
+					 val);
+		if (ret < 0)
+			return ret;
+
+		return val;
+	default:
+		return -EINVAL;
+	}
+}
+
+static irqreturn_t irsd200_irq_thread(int irq, void *dev_id)
+{
+	struct iio_dev *indio_dev = dev_id;
+	struct irsd200_data *data = iio_priv(indio_dev);
+	enum iio_event_direction dir;
+	unsigned int lower_count;
+	unsigned int upper_count;
+	unsigned int status = 0;
+	unsigned int source = 0;
+	unsigned int clear = 0;
+	unsigned int count = 0;
+	int ret;
+
+	ret = regmap_read(data->regmap, IRS_REG_INTR, &source);
+	if (ret) {
+		dev_err(data->dev, "Could not read interrupt source (%d)\n",
+			ret);
+		return IRQ_NONE;
+	}
+
+	ret = regmap_read(data->regmap, IRS_REG_STATUS, &status);
+	if (ret) {
+		dev_err(data->dev, "Could not acknowledge interrupt (%d)\n",
+			ret);
+		return IRQ_NONE;
+	}
+
+	if (status & BIT(IRS_INTR_DATA) && iio_buffer_enabled(indio_dev)) {
+		iio_trigger_poll_nested(indio_dev->trig);
+		clear |= BIT(IRS_INTR_DATA);
+	}
+
+	if (status & BIT(IRS_INTR_TIMER) && source & BIT(IRS_INTR_TIMER)) {
+		iio_push_event(indio_dev,
+			       IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0,
+						    IIO_EV_TYPE_CHANGE,
+						    IIO_EV_DIR_NONE),
+			       iio_get_time_ns(indio_dev));
+		clear |= BIT(IRS_INTR_TIMER);
+	}
+
+	if (status & BIT(IRS_INTR_COUNT_THR_OR) &&
+	    source & BIT(IRS_INTR_COUNT_THR_OR)) {
+		/*
+		 * The register value resets to zero after reading. We therefore
+		 * need to read once and manually extract the lower and upper
+		 * count register fields.
+		 */
+		ret = regmap_read(data->regmap, IRS_REG_COUNT, &count);
+		if (ret)
+			dev_err(data->dev, "Could not read count (%d)\n", ret);
+
+		upper_count = IRS_UPPER_COUNT(count);
+		lower_count = IRS_LOWER_COUNT(count);
+
+		/*
+		 * We only check the OR mode to be able to push events for
+		 * rising and falling thresholds. AND mode is covered when both
+		 * upper and lower count is non-zero, and is signaled with
+		 * IIO_EV_DIR_EITHER.
+		 */
+		if (upper_count && !lower_count)
+			dir = IIO_EV_DIR_RISING;
+		else if (!upper_count && lower_count)
+			dir = IIO_EV_DIR_FALLING;
+		else
+			dir = IIO_EV_DIR_EITHER;
+
+		iio_push_event(indio_dev,
+			       IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0,
+						    IIO_EV_TYPE_THRESH, dir),
+			       iio_get_time_ns(indio_dev));
+
+		/*
+		 * The OR mode will always trigger when the AND mode does, but
+		 * not vice versa. However, it seems like the AND bit needs to
+		 * be cleared if data capture _and_ threshold count interrupts
+		 * are desirable, even though it hasn't explicitly been selected
+		 * (with IRS_REG_INTR). Either way, it doesn't hurt...
+		 */
+		clear |= BIT(IRS_INTR_COUNT_THR_OR) |
+			 BIT(IRS_INTR_COUNT_THR_AND);
+	}
+
+	if (clear) {
+		ret = regmap_write(data->regmap, IRS_REG_STATUS, clear);
+		if (ret)
+			dev_err(data->dev,
+				"Could not clear interrupt status (%d)\n", ret);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t irsd200_trigger_handler(int irq, void *pollf)
+{
+	struct iio_dev *indio_dev = ((struct iio_poll_func *)pollf)->indio_dev;
+	struct irsd200_data *data = iio_priv(indio_dev);
+	s16 buf = 0;
+	int ret;
+
+	ret = irsd200_read_data(data, &buf);
+	if (ret)
+		goto end;
+
+	iio_push_to_buffers_with_timestamp(indio_dev, &buf,
+					   iio_get_time_ns(indio_dev));
+
+end:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return ret ? IRQ_NONE : IRQ_HANDLED;
+}
+
+static int irsd200_buf_postenable(struct iio_dev *indio_dev)
+{
+	struct irsd200_data *data = iio_priv(indio_dev);
+	int ret;
+
+	ret = regmap_field_write(data->regfields[IRS_REGF_INTR_DATA], 1);
+	if (ret) {
+		dev_err(data->dev,
+			"Could not enable data interrupt source (%d)\n", ret);
+	}
+
+	return ret;
+}
+
+static int irsd200_buf_predisable(struct iio_dev *indio_dev)
+{
+	struct irsd200_data *data = iio_priv(indio_dev);
+	int ret;
+
+	ret = regmap_field_write(data->regfields[IRS_REGF_INTR_DATA], 0);
+	if (ret) {
+		dev_err(data->dev,
+			"Could not disable data interrupt source (%d)\n", ret);
+	}
+
+	return ret;
+}
+
+static const struct iio_info irsd200_info = {
+	.read_raw = irsd200_read_raw,
+	.read_avail = irsd200_read_avail,
+	.write_raw = irsd200_write_raw,
+	.read_event_value = irsd200_read_event,
+	.write_event_value = irsd200_write_event,
+	.read_event_config = irsd200_read_event_config,
+	.write_event_config = irsd200_write_event_config,
+};
+
+static const struct iio_buffer_setup_ops irsd200_buf_ops = {
+	.postenable = &irsd200_buf_postenable,
+	.predisable = &irsd200_buf_predisable,
+};
+
+static const struct iio_trigger_ops irsd200_trigger_ops = {
+	.validate_device = iio_trigger_validate_own_device,
+};
+
+static const struct iio_event_spec irsd200_event_spec[] = {
+	/* Upper threshold value. */
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_RISING,
+		.mask_separate =
+			BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_ENABLE),
+	},
+	/* Lower threshold value. */
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_FALLING,
+		.mask_separate =
+			BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_ENABLE),
+	},
+	/* Window time. */
+	{
+		.type = IIO_EV_TYPE_CHANGE,
+		.dir = IIO_EV_DIR_NONE,
+		.mask_separate =
+			BIT(IIO_EV_INFO_TIMEOUT) | BIT(IIO_EV_INFO_ENABLE),
+	},
+	/* Number of counts (exceeding thresholds) before interrupt. */
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_EITHER,
+		.mask_separate = BIT(IIO_EV_INFO_PERIOD),
+	},
+	/* Low-pass filter frequency. */
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_EITHER,
+		.mask_separate = BIT(IIO_EV_INFO_LOW_PASS_FILTER_3DB),
+	},
+	/* High-pass filter frequency. */
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_EITHER,
+		.mask_separate = BIT(IIO_EV_INFO_HIGH_PASS_FILTER_3DB),
+	},
+};
+
+static const struct iio_chan_spec irsd200_channels[] = {
+	{
+		.type = IIO_PROXIMITY,
+		.info_mask_separate =
+			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SAMP_FREQ),
+		.info_mask_separate_available = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+		.event_spec = irsd200_event_spec,
+		.num_event_specs = ARRAY_SIZE(irsd200_event_spec),
+		.scan_type = {
+			.sign = 's',
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_CPU,
+		},
+	},
+};
+
+static int irsd200_probe(struct i2c_client *client)
+{
+	struct iio_trigger *trigger;
+	struct irsd200_data *data;
+	struct iio_dev *indio_dev;
+	struct regmap *regmap;
+	size_t i;
+	int ret;
+
+	regmap = devm_regmap_init_i2c(client, &irsd200_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&client->dev, "Could not initialize regmap\n");
+		return PTR_ERR(regmap);
+	}
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev) {
+		dev_err(&client->dev, "Could not allocate iio device\n");
+		return -ENOMEM;
+	}
+
+	data = iio_priv(indio_dev);
+	data->regmap = regmap;
+	data->dev = &client->dev;
+	i2c_set_clientdata(client, indio_dev);
+
+	for (i = 0; i < IRS_REGF_MAX; ++i) {
+		data->regfields[i] = devm_regmap_field_alloc(
+			data->dev, data->regmap, irsd200_regfields[i]);
+		if (IS_ERR(data->regfields[i])) {
+			dev_err(data->dev,
+				"Could not allocate register field %zu\n", i);
+			return PTR_ERR(data->regfields[i]);
+		}
+	}
+
+	ret = irsd200_setup(data);
+	if (ret)
+		return ret;
+
+	indio_dev->info = &irsd200_info;
+	indio_dev->name = IRS_DRV_NAME;
+	indio_dev->channels = irsd200_channels;
+	indio_dev->num_channels = ARRAY_SIZE(irsd200_channels);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	if (!client->irq) {
+		dev_err(&client->dev, "No irq available\n");
+		return -ENXIO;
+	}
+
+	ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, NULL,
+					      irsd200_trigger_handler,
+					      &irsd200_buf_ops);
+	if (ret) {
+		dev_err(&client->dev,
+			"Could not setup iio triggered buffer (%d)\n", ret);
+		return ret;
+	}
+
+	ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
+					irsd200_irq_thread,
+					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+					NULL, indio_dev);
+	if (ret) {
+		return dev_err_probe(&client->dev, ret,
+				     "Could not request irq (%d)\n", ret);
+	}
+
+	trigger = devm_iio_trigger_alloc(&client->dev, "%s-dev%d",
+					 indio_dev->name,
+					 iio_device_id(indio_dev));
+	if (!trigger) {
+		dev_err(&client->dev, "Could not allocate iio trigger\n");
+		return -ENOMEM;
+	}
+
+	trigger->ops = &irsd200_trigger_ops;
+	iio_trigger_set_drvdata(trigger, indio_dev);
+
+	ret = devm_iio_trigger_register(&client->dev, trigger);
+	if (ret) {
+		dev_err(&client->dev, "Could not register iio trigger (%d)\n",
+			ret);
+		return ret;
+	}
+
+	ret = devm_iio_device_register(&client->dev, indio_dev);
+	if (ret) {
+		dev_err(&client->dev, "Could not register iio device (%d)\n",
+			ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id irsd200_of_match[] = {
+	{
+		.compatible = "murata,irsd200",
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, irsd200_of_match);
+
+static struct i2c_driver irsd200_driver = {
+	.driver = {
+		.name = IRS_DRV_NAME,
+		.of_match_table = irsd200_of_match,
+	},
+	.probe = irsd200_probe,
+};
+module_i2c_driver(irsd200_driver);
+
+MODULE_AUTHOR("Waqar Hameed <waqar.hameed@xxxxxxxx>");
+MODULE_DESCRIPTION("Murata IRS-D200 PIR sensor driver");
+MODULE_LICENSE("GPL");
-- 
2.30.2