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From: Mudit Sharma <muditsharma.info@gmail.com>
To: jic23@kernel.org,
	lars@metafoo.de,
	krzk+dt@kernel.org,
	conor+dt@kernel.org,
	robh@kernel.org
Cc: ivan.orlov0322@gmail.com,
	javier.carrasco.cruz@gmail.com,
	Mudit Sharma <muditsharma.info@gmail.com>,
	linux-kernel@vger.kernel.org,
	linux-iio@vger.kernel.org,
	devicetree@vger.kernel.org
Subject: [PATCH v4 2/2] iio: light: ROHM BH1745 colour sensor
Date: Thu,  6 Jun 2024 17:29:42 +0100
Message-ID: <20240606162948.83903-2-muditsharma.info@gmail.com>
In-Reply-To: <20240606162948.83903-1-muditsharma.info@gmail.com>
References: <20240606162948.83903-1-muditsharma.info@gmail.com>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

Add support for BH1745, which is an I2C colour sensor with red, green,
blue and clear channels. It has a programmable active low interrupt
pin. Interrupt occurs when the signal from the selected interrupt
source channel crosses set interrupt threshold high or low level.

This driver includes device attributes to configure the following:
- Interrupt pin latch: The interrupt pin can be configured to
  be latched (until interrupt register (0x60) is read or initialized)
  or update after each measurement.
- Interrupt source: The colour channel that will cause the interrupt
  when channel will cross the set threshold high or low level.

This driver also includes device attributes to present valid
configuration options/values for:
- Integration time
- Interrupt colour source
- Hardware gain

Add myself as the maintainer for this driver in MAINTAINERS.

Signed-off-by: Mudit Sharma <muditsharma.info@gmail.com>
Reviewed-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Reviewed-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
---
v3->v4:
- Fix formatting:
  - Remove redundant new line
  - Use '0x' rather than '0X'
v2->v3:
- Squash commit for addition to MAINTAINERS
- Fix code style for consistency:
  - New line before last 'return'
  - Use variable name 'value' instead of 'val' in
    'bh1745_set_trigger_state()'
  - Align function parameters to match parenthesis
  - Avoid use of magic number
- Use named enum instead of anonymous enum
- Use 'guard(mutex)(&data->lock)' instead of 'mutex_lock()'
  'mutex_unlock()'
- Only initialize 'ret' and 'value' when necessary
- Fix and optimize logic for `in_interrupt_latch_store()` 
- Fix error handling in irq , trigger handlers and dev attribute for
  latch
v1->v2:
- No changes

 MAINTAINERS                |   6 +
 drivers/iio/light/Kconfig  |  12 +
 drivers/iio/light/Makefile |   1 +
 drivers/iio/light/bh1745.c | 863 +++++++++++++++++++++++++++++++++++++
 4 files changed, 882 insertions(+)
 create mode 100644 drivers/iio/light/bh1745.c

diff --git a/MAINTAINERS b/MAINTAINERS
index d6c90161c7bf..024c14738dc7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19407,6 +19407,12 @@ S:	Supported
 F:	drivers/power/supply/bd99954-charger.c
 F:	drivers/power/supply/bd99954-charger.h
 
+ROHM BH1745 COLOUR SENSOR
+M:	Mudit Sharma <muditsharma.info@gmail.com>
+L:	linux-iio@vger.kernel.org
+S:	Maintained
+F:	drivers/iio/light/bh1745.c
+
 ROHM BH1750 AMBIENT LIGHT SENSOR DRIVER
 M:	Tomasz Duszynski <tduszyns@gmail.com>
 S:	Maintained
diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
index 9a587d403118..6e0bd2addf9e 100644
--- a/drivers/iio/light/Kconfig
+++ b/drivers/iio/light/Kconfig
@@ -114,6 +114,18 @@ config AS73211
 	 This driver can also be built as a module.  If so, the module
 	 will be called as73211.
 
+config BH1745
+	tristate "ROHM BH1745 colour sensor"
+	depends on I2C
+	select REGMAP_I2C
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say Y here to build support for the ROHM bh1745 colour sensor.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called bh1745.
+
 config BH1750
 	tristate "ROHM BH1750 ambient light sensor"
 	depends on I2C
diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
index a30f906e91ba..939a701a06ac 100644
--- a/drivers/iio/light/Makefile
+++ b/drivers/iio/light/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_APDS9300)		+= apds9300.o
 obj-$(CONFIG_APDS9306)		+= apds9306.o
 obj-$(CONFIG_APDS9960)		+= apds9960.o
 obj-$(CONFIG_AS73211)		+= as73211.o
+obj-$(CONFIG_BH1745)		+= bh1745.o
 obj-$(CONFIG_BH1750)		+= bh1750.o
 obj-$(CONFIG_BH1780)		+= bh1780.o
 obj-$(CONFIG_CM32181)		+= cm32181.o
diff --git a/drivers/iio/light/bh1745.c b/drivers/iio/light/bh1745.c
new file mode 100644
index 000000000000..7962cf1c4b52
--- /dev/null
+++ b/drivers/iio/light/bh1745.c
@@ -0,0 +1,863 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ROHM BH1745 digital colour sensor driver
+ *
+ * Copyright (C) Mudit Sharma <muditsharma.info@gmail.com>
+ *
+ * 7-bit I2C slave addresses:
+ *  0x38 (ADDR pin low)
+ *  0x39 (ADDR pin high)
+ *
+ */
+
+#include <linux/i2c.h>
+#include <linux/mutex.h>
+#include <linux/util_macros.h>
+#include <linux/iio/events.h>
+#include <linux/regmap.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#define BH1745_MOD_NAME "bh1745"
+
+/* BH1745 config regs */
+#define BH1745_SYS_CTRL 0x40
+
+#define BH1745_MODE_CTRL_1 0x41
+#define BH1745_MODE_CTRL_2 0x42
+#define BH1745_MODE_CTRL_3 0x44
+
+#define BH1745_INTR 0x60
+#define BH1745_INTR_STATUS BIT(7)
+
+#define BH1745_PERSISTENCE 0x61
+
+#define BH1745_TH_LSB 0x62
+#define BH1745_TH_MSB 0x63
+
+#define BH1745_TL_LSB 0x64
+#define BH1745_TL_MSB 0x65
+
+#define BH1745_THRESHOLD_MAX 0xFFFF
+#define BH1745_THRESHOLD_MIN 0x0
+
+#define BH1745_MANU_ID 0X92
+
+/* BH1745 output regs */
+#define BH1745_R_LSB 0x50
+#define BH1745_R_MSB 0x51
+#define BH1745_G_LSB 0x52
+#define BH1745_G_MSB 0x53
+#define BH1745_B_LSB 0x54
+#define BH1745_B_MSB 0x55
+#define BH1745_CLR_LSB 0x56
+#define BH1745_CLR_MSB 0x57
+
+#define BH1745_SW_RESET BIT(7)
+#define BH1745_INT_RESET BIT(6)
+
+#define BH1745_MEASUREMENT_TIME_MASK GENMASK(2, 0)
+
+#define BH1745_RGBC_EN BIT(4)
+
+#define BH1745_ADC_GAIN_MASK GENMASK(1, 0)
+
+#define BH1745_INT_ENABLE BIT(0)
+#define BH1745_INT_SIGNAL_ACTIVE BIT(7)
+
+#define BH1745_INT_SIGNAL_LATCHED BIT(4)
+#define BH1745_INT_SIGNAL_LATCH_OFFSET 4
+
+#define BH1745_INT_SOURCE_MASK GENMASK(3, 2)
+#define BH1745_INT_SOURCE_OFFSET 2
+
+#define BH1745_INT_TIME_AVAILABLE "0.16 0.32 0.64 1.28 2.56 5.12"
+#define BH1745_HARDWAREGAIN_AVAILABLE "1 2 16"
+#define BH1745_INT_COLOUR_CHANNEL_AVAILABLE \
+	"0 (Red Channel) 1 (Green Channel) 2 (Blue channel) 3 (Clear channel)"
+
+static const int bh1745_int_time[][2] = {
+	{ 0, 160000 }, /* 160 ms */
+	{ 0, 320000 }, /* 320 ms */
+	{ 0, 640000 }, /* 640 ms */
+	{ 1, 280000 }, /* 1280 ms */
+	{ 2, 560000 }, /* 2560 ms */
+	{ 5, 120000 }, /* 5120 ms */
+};
+
+static const u8 bh1745_gain_factor[] = { 1, 2, 16 };
+
+enum bh1745_int_source {
+	BH1745_INT_SOURCE_RED,
+	BH1745_INT_SOURCE_GREEN,
+	BH1745_INT_SOURCE_BLUE,
+	BH1745_INT_SOURCE_CLEAR,
+};
+
+enum bh1745_gain {
+	BH1745_ADC_GAIN_1X,
+	BH1745_ADC_GAIN_2X,
+	BH1745_ADC_GAIN_16X,
+};
+
+enum bh1745_measurement_time {
+	BH1745_MEASUREMENT_TIME_160MS,
+	BH1745_MEASUREMENT_TIME_320MS,
+	BH1745_MEASUREMENT_TIME_640MS,
+	BH1745_MEASUREMENT_TIME_1280MS,
+	BH1745_MEASUREMENT_TIME_2560MS,
+	BH1745_MEASUREMENT_TIME_5120MS,
+};
+
+enum bh1745_presistence_value {
+	BH1745_PRESISTENCE_UPDATE_TOGGLE,
+	BH1745_PRESISTENCE_UPDATE_EACH_MEASUREMENT,
+	BH1745_PRESISTENCE_UPDATE_FOUR_MEASUREMENT,
+	BH1745_PRESISTENCE_UPDATE_EIGHT_MEASUREMENT,
+};
+
+struct bh1745_data {
+	struct mutex lock;
+	struct regmap *regmap;
+	struct i2c_client *client;
+	struct iio_trigger *trig;
+	u8 mode_ctrl1;
+	u8 mode_ctrl2;
+	u8 int_src;
+	u8 int_latch;
+	u8 interrupt;
+};
+
+static const struct regmap_range bh1745_volatile_ranges[] = {
+	regmap_reg_range(BH1745_MODE_CTRL_2, BH1745_MODE_CTRL_2), /* VALID */
+	regmap_reg_range(BH1745_R_LSB, BH1745_CLR_MSB), /* Data */
+	regmap_reg_range(BH1745_INTR, BH1745_INTR), /* Interrupt */
+};
+
+static const struct regmap_access_table bh1745_volatile_regs = {
+	.yes_ranges = bh1745_volatile_ranges,
+	.n_yes_ranges = ARRAY_SIZE(bh1745_volatile_ranges),
+};
+
+static const struct regmap_range bh1745_read_ranges[] = {
+	regmap_reg_range(BH1745_SYS_CTRL, BH1745_MODE_CTRL_2),
+	regmap_reg_range(BH1745_R_LSB, BH1745_CLR_MSB),
+	regmap_reg_range(BH1745_INTR, BH1745_INTR),
+	regmap_reg_range(BH1745_PERSISTENCE, BH1745_TL_MSB),
+	regmap_reg_range(BH1745_MANU_ID, BH1745_MANU_ID),
+};
+
+static const struct regmap_access_table bh1745_ro_regs = {
+	.yes_ranges = bh1745_read_ranges,
+	.n_yes_ranges = ARRAY_SIZE(bh1745_read_ranges),
+};
+
+static const struct regmap_range bh1745_writable_ranges[] = {
+	regmap_reg_range(BH1745_SYS_CTRL, BH1745_MODE_CTRL_2),
+	regmap_reg_range(BH1745_PERSISTENCE, BH1745_TL_MSB),
+};
+
+static const struct regmap_access_table bh1745_wr_regs = {
+	.yes_ranges = bh1745_writable_ranges,
+	.n_yes_ranges = ARRAY_SIZE(bh1745_writable_ranges),
+};
+
+static const struct regmap_config bh1745_regmap = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = BH1745_MANU_ID,
+	.cache_type = REGCACHE_RBTREE,
+	.volatile_table = &bh1745_volatile_regs,
+	.wr_table = &bh1745_wr_regs,
+	.rd_table = &bh1745_ro_regs,
+};
+
+static const struct iio_event_spec bh1745_event_spec[] = {
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_RISING,
+		.mask_shared_by_type = BIT(IIO_EV_INFO_VALUE),
+	},
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_FALLING,
+		.mask_shared_by_type = BIT(IIO_EV_INFO_VALUE),
+	},
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_EITHER,
+		.mask_shared_by_type = BIT(IIO_EV_INFO_PERIOD),
+	},
+};
+
+#define BH1745_CHANNEL(_colour, _si, _addr)                                   \
+	{                                                                     \
+		.type = IIO_INTENSITY, .modified = 1,                         \
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),                 \
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_HARDWAREGAIN) | \
+					    BIT(IIO_CHAN_INFO_INT_TIME),      \
+		.event_spec = bh1745_event_spec,                              \
+		.num_event_specs = ARRAY_SIZE(bh1745_event_spec),             \
+		.channel2 = IIO_MOD_LIGHT_##_colour, .address = _addr,        \
+		.scan_index = _si,                                            \
+		.scan_type = {                                                \
+			.sign = 'u',                                          \
+			.realbits = 16,                                       \
+			.storagebits = 16,                                    \
+			.endianness = IIO_CPU,                                \
+		},                                                            \
+	}
+
+static const struct iio_chan_spec bh1745_channels[] = {
+	BH1745_CHANNEL(RED, 0, BH1745_R_LSB),
+	BH1745_CHANNEL(GREEN, 1, BH1745_G_LSB),
+	BH1745_CHANNEL(BLUE, 2, BH1745_B_LSB),
+	BH1745_CHANNEL(CLEAR, 3, BH1745_CLR_LSB),
+	IIO_CHAN_SOFT_TIMESTAMP(4),
+};
+
+static int bh1745_write_value(struct bh1745_data *data, u8 reg, void *value,
+			      size_t len)
+{
+	int ret;
+
+	ret = regmap_bulk_write(data->regmap, reg, value, len);
+	if (ret < 0) {
+		dev_err(&data->client->dev,
+			"Failed to write to sensor. Reg: 0x%x\n", reg);
+	}
+
+	return ret;
+}
+
+static int bh1745_read_value(struct bh1745_data *data, u8 reg, void *value,
+			     size_t len)
+{
+	int ret;
+
+	ret = regmap_bulk_read(data->regmap, reg, value, len);
+	if (ret < 0) {
+		dev_err(&data->client->dev,
+			"Failed to read from sensor. Reg: 0x%x\n", reg);
+	}
+
+	return ret;
+}
+
+static ssize_t in_interrupt_source_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	int ret;
+	int value;
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct bh1745_data *data = iio_priv(indio_dev);
+
+	ret = bh1745_read_value(data, BH1745_INTR, &value, 1);
+	if (ret < 0)
+		return ret;
+
+	value &= BH1745_INT_SOURCE_MASK;
+
+	return sprintf(buf, "%d\n", value >> 2);
+}
+
+static ssize_t in_interrupt_source_store(struct device *dev,
+					 struct device_attribute *attr,
+					 const char *buf, size_t len)
+{
+	int ret;
+	u16 value;
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct bh1745_data *data = iio_priv(indio_dev);
+
+	ret = kstrtou16(buf, 10, &value);
+	if (ret < 0)
+		return ret;
+
+	if (value > BH1745_INT_SOURCE_CLEAR) {
+		dev_err(dev,
+			"Supplied value: '%d' for interrupt source is invalid\n",
+			value);
+		return -EINVAL;
+	}
+	guard(mutex)(&data->lock);
+	data->int_src = value;
+	value = value << BH1745_INT_SOURCE_OFFSET;
+	ret = bh1745_read_value(data, BH1745_INTR, &data->interrupt, 1);
+	if (ret < 0)
+		return ret;
+
+	data->interrupt &= ~BH1745_INT_SOURCE_MASK;
+	data->interrupt |= value;
+	ret = bh1745_write_value(data, BH1745_INTR, &data->interrupt, 1);
+	if (ret < 0)
+		return ret;
+
+	return len;
+}
+
+static ssize_t in_interrupt_latch_show(struct device *dev,
+				       struct device_attribute *attr, char *buf)
+{
+	int ret;
+	int value;
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct bh1745_data *data = iio_priv(indio_dev);
+
+	ret = bh1745_read_value(data, BH1745_INTR, &value, 1);
+	if (ret < 0)
+		return ret;
+
+	value &= BH1745_INT_SIGNAL_LATCHED;
+	if (value)
+		return sprintf(buf, "1\n");
+
+	return sprintf(buf, "0\n");
+}
+
+static ssize_t in_interrupt_latch_store(struct device *dev,
+					struct device_attribute *attr,
+					const char *buf, size_t len)
+{
+	int ret;
+	u16 value;
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct bh1745_data *data = iio_priv(indio_dev);
+
+	ret = kstrtou16(buf, 10, &value);
+	if (ret < 0)
+		return ret;
+
+	if (value > 1) {
+		dev_err(dev, "Value out of range for latch setup. Supported values '0' or '1'\n");
+		return -EINVAL;
+	}
+
+	guard(mutex)(&data->lock);
+	data->int_latch = value;
+	ret = bh1745_read_value(data, BH1745_INTR, &data->interrupt, 1);
+	if (ret < 0)
+		return ret;
+
+	if (value == 0)
+		data->interrupt &= ~BH1745_INT_SIGNAL_LATCHED;
+	else
+		data->interrupt |= BH1745_INT_SIGNAL_LATCHED;
+
+	ret = bh1745_write_value(data, BH1745_INTR, &data->interrupt, 1);
+	if (ret < 0)
+		return ret;
+
+	return len;
+}
+
+static ssize_t hardwaregain_available_show(struct device *dev,
+					   struct device_attribute *attr,
+					   char *buf)
+{
+	return sprintf(buf, "%s\n", BH1745_HARDWAREGAIN_AVAILABLE);
+}
+
+static ssize_t interrupt_source_available_show(struct device *dev,
+					       struct device_attribute *attr,
+					       char *buf)
+{
+	return sprintf(buf, "%s\n", BH1745_INT_COLOUR_CHANNEL_AVAILABLE);
+}
+
+static IIO_DEVICE_ATTR_RW(in_interrupt_source, 0);
+static IIO_DEVICE_ATTR_RW(in_interrupt_latch, 0);
+static IIO_DEVICE_ATTR_RO(hardwaregain_available, 0);
+static IIO_DEVICE_ATTR_RO(interrupt_source_available, 0);
+static IIO_CONST_ATTR_INT_TIME_AVAIL(BH1745_INT_TIME_AVAILABLE);
+
+static struct attribute *bh1745_attrs[] = {
+	&iio_dev_attr_in_interrupt_source.dev_attr.attr,
+	&iio_dev_attr_in_interrupt_latch.dev_attr.attr,
+	&iio_dev_attr_hardwaregain_available.dev_attr.attr,
+	&iio_dev_attr_interrupt_source_available.dev_attr.attr,
+	&iio_const_attr_integration_time_available.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group bh1745_attr_group = {
+	.attrs = bh1745_attrs,
+};
+
+static int bh1745_reset(struct bh1745_data *data)
+{
+	int ret;
+	u8 value;
+
+	ret = bh1745_read_value(data, BH1745_SYS_CTRL, &value, 1);
+	if (ret < 0)
+		return ret;
+
+	value |= (BH1745_SW_RESET | BH1745_INT_RESET);
+
+	return bh1745_write_value(data, BH1745_SYS_CTRL, &value, 1);
+}
+
+static int bh1745_power_on(struct bh1745_data *data)
+{
+	int ret;
+	u8 value;
+
+	ret = bh1745_read_value(data, BH1745_MODE_CTRL_2, &value, 1);
+	if (ret < 0)
+		return ret;
+
+	guard(mutex)(&data->lock);
+	value |= BH1745_RGBC_EN;
+	data->mode_ctrl2 = value;
+	ret = bh1745_write_value(data, BH1745_MODE_CTRL_2, &data->mode_ctrl2, 1);
+
+	return ret;
+}
+
+static int bh1745_power_off(struct bh1745_data *data)
+{
+	int ret;
+	int value;
+
+	ret = bh1745_read_value(data, BH1745_MODE_CTRL_2, &value, 1);
+	if (ret < 0)
+		return ret;
+
+	guard(mutex)(&data->lock);
+	value &= ~BH1745_RGBC_EN;
+	data->mode_ctrl2 = value;
+	ret = bh1745_write_value(data, BH1745_MODE_CTRL_2, &data->mode_ctrl2, 1);
+
+	return ret;
+}
+
+static int bh1745_set_int_time(struct bh1745_data *data, int val, int val2)
+{
+	int ret;
+
+	for (u8 i = 0; i < ARRAY_SIZE(bh1745_int_time); i++) {
+		if (val == bh1745_int_time[i][0] &&
+		    val2 == bh1745_int_time[i][1]) {
+			guard(mutex)(&data->lock);
+			data->mode_ctrl1 &= ~BH1745_MEASUREMENT_TIME_MASK;
+			data->mode_ctrl1 |= i;
+			ret = bh1745_write_value(data, BH1745_MODE_CTRL_1,
+						 &data->mode_ctrl1, 1);
+			return ret;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static int bh1745_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan, int *val,
+			   int *val2, long mask)
+{
+	struct bh1745_data *data = iio_priv(indio_dev);
+	int ret;
+	u16 value;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW: {
+		ret = iio_device_claim_direct_mode(indio_dev);
+		if (ret)
+			return ret;
+		ret = bh1745_read_value(data, chan->address, &value, 2);
+		if (ret < 0)
+			return ret;
+		iio_device_release_direct_mode(indio_dev);
+		*val = value;
+		return IIO_VAL_INT;
+	}
+
+	case IIO_CHAN_INFO_HARDWAREGAIN: {
+		guard(mutex)(&data->lock);
+		ret = bh1745_read_value(data, BH1745_MODE_CTRL_2,
+					&data->mode_ctrl2, 1);
+		if (ret < 0)
+			return ret;
+
+		value = data->mode_ctrl2 & BH1745_ADC_GAIN_MASK;
+		*val = bh1745_gain_factor[value];
+		return IIO_VAL_INT;
+	}
+
+	case IIO_CHAN_INFO_INT_TIME: {
+		guard(mutex)(&data->lock);
+		ret = bh1745_read_value(data, BH1745_MODE_CTRL_1,
+					&data->mode_ctrl1, 1);
+		if (ret < 0)
+			return ret;
+
+		value = data->mode_ctrl1 & BH1745_MEASUREMENT_TIME_MASK;
+
+		*val = bh1745_int_time[value][0];
+		*val2 = bh1745_int_time[value][1];
+
+		return IIO_VAL_INT_PLUS_MICRO;
+	}
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int bh1745_write_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan, int val, int val2,
+			    long mask)
+{
+	struct bh1745_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_HARDWAREGAIN: {
+		for (u8 i = 0; i < ARRAY_SIZE(bh1745_gain_factor); i++) {
+			if (bh1745_gain_factor[i] == val) {
+				guard(mutex)(&data->lock);
+				data->mode_ctrl2 &= ~BH1745_ADC_GAIN_MASK;
+				data->mode_ctrl2 |= i;
+				ret = bh1745_write_value(data,
+							 BH1745_MODE_CTRL_2,
+							 &data->mode_ctrl2, 1);
+				return ret;
+			}
+		}
+		return -EINVAL;
+	}
+
+	case IIO_CHAN_INFO_INT_TIME: {
+		return bh1745_set_int_time(data, val, val2);
+	}
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int bh1745_read_thresh(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 bh1745_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (info) {
+	case IIO_EV_INFO_VALUE:
+		switch (dir) {
+		case IIO_EV_DIR_RISING:
+			ret = bh1745_read_value(data, BH1745_TH_LSB, val, 2);
+			if (ret < 0)
+				return ret;
+			return IIO_VAL_INT;
+		case IIO_EV_DIR_FALLING:
+			ret = bh1745_read_value(data, BH1745_TL_LSB, val, 2);
+			if (ret < 0)
+				return ret;
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+		break;
+	case IIO_EV_INFO_PERIOD:
+		ret = bh1745_read_value(data, BH1745_PERSISTENCE, val, 1);
+		if (ret < 0)
+			return ret;
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int bh1745_write_thresh(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 bh1745_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (info) {
+	case IIO_EV_INFO_VALUE:
+		if (val < BH1745_THRESHOLD_MIN || val > BH1745_THRESHOLD_MAX)
+			return -EINVAL;
+		switch (dir) {
+		case IIO_EV_DIR_RISING:
+			ret = bh1745_write_value(data, BH1745_TH_LSB, &val, 2);
+			if (ret < 0)
+				return ret;
+			return IIO_VAL_INT;
+		case IIO_EV_DIR_FALLING:
+			ret = bh1745_write_value(data, BH1745_TL_LSB, &val, 2);
+			if (ret < 0)
+				return ret;
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+		break;
+	case IIO_EV_INFO_PERIOD:
+		if (val < BH1745_PRESISTENCE_UPDATE_TOGGLE ||
+		    val > BH1745_PRESISTENCE_UPDATE_EIGHT_MEASUREMENT)
+			return -EINVAL;
+		ret = bh1745_write_value(data, BH1745_PERSISTENCE, &val, 1);
+		if (ret < 0)
+			return ret;
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info bh1745_info = {
+	.attrs = &bh1745_attr_group,
+	.read_raw = bh1745_read_raw,
+	.write_raw = bh1745_write_raw,
+	.read_event_value = bh1745_read_thresh,
+	.write_event_value = bh1745_write_thresh,
+
+};
+
+static void bh1745_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct bh1745_data *data = iio_priv(indio_dev);
+
+	if (bh1745_power_off(data) < 0)
+		dev_err(&data->client->dev, "Failed to turn off device");
+
+	dev_info(&data->client->dev, "BH1745 driver removed\n");
+}
+
+static int bh1745_set_trigger_state(struct iio_trigger *trig, bool state)
+{
+	int ret;
+	u8 value = 0;
+	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+	struct bh1745_data *data = iio_priv(indio_dev);
+
+	guard(mutex)(&data->lock);
+	if (state) {
+		ret = bh1745_read_value(data, BH1745_INTR, &value, 1);
+		if (ret < 0)
+			return ret;
+		value |= (BH1745_INT_ENABLE |
+			(data->int_latch << BH1745_INT_SIGNAL_LATCH_OFFSET) |
+			(data->int_src << BH1745_INT_SOURCE_OFFSET));
+		data->interrupt = value;
+		ret = bh1745_write_value(data, BH1745_INTR, &data->interrupt, 1);
+	} else {
+		data->interrupt = value;
+		ret = bh1745_write_value(data, BH1745_INTR, &data->interrupt, 1);
+	}
+
+	return ret;
+}
+
+static const struct iio_trigger_ops bh1745_trigger_ops = {
+	.set_trigger_state = bh1745_set_trigger_state,
+};
+
+static irqreturn_t bh1745_interrupt_handler(int interrupt, void *p)
+{
+	struct iio_dev *indio_dev = p;
+	struct bh1745_data *data = iio_priv(indio_dev);
+	int ret;
+	int value;
+
+	ret = bh1745_read_value(data, BH1745_INTR, &value, 1);
+	if (ret < 0)
+		return IRQ_NONE;
+
+	if (value & BH1745_INTR_STATUS) {
+		guard(mutex)(&data->lock);
+		iio_push_event(indio_dev,
+			       IIO_UNMOD_EVENT_CODE(IIO_INTENSITY,
+						    data->int_src,
+						    IIO_EV_TYPE_THRESH,
+						    IIO_EV_DIR_EITHER),
+			       iio_get_time_ns(indio_dev));
+
+		iio_trigger_poll_nested(data->trig);
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_NONE;
+}
+
+static irqreturn_t bh1745_trigger_handler(int interrupt, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct bh1745_data *data = iio_priv(indio_dev);
+	struct {
+		u16 chans[4];
+		s64 timestamp __aligned(8);
+	} scan;
+	u16 value;
+	int ret;
+	int i, j = 0;
+
+	for_each_set_bit(i, indio_dev->active_scan_mask, indio_dev->masklength) {
+		ret = bh1745_read_value(data, BH1745_R_LSB + 2 * i, &value, 2);
+		if (ret < 0)
+			goto err;
+		scan.chans[j++] = value;
+	}
+
+	iio_push_to_buffers_with_timestamp(indio_dev, &scan,
+					   iio_get_time_ns(indio_dev));
+
+err:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int bh1745_setup_trigger(struct iio_dev *indio_dev)
+{
+	struct bh1745_data *data = iio_priv(indio_dev);
+	int ret;
+
+	data->trig = devm_iio_trigger_alloc(indio_dev->dev.parent,
+					    "%sdata-rdy-dev%d", indio_dev->name,
+					    iio_device_id(indio_dev));
+	if (!data->trig)
+		return -ENOMEM;
+
+	data->trig->ops = &bh1745_trigger_ops;
+	iio_trigger_set_drvdata(data->trig, indio_dev);
+
+	ret = devm_iio_trigger_register(&data->client->dev, data->trig);
+	if (ret)
+		return dev_err_probe(&data->client->dev, ret,
+				     "Trigger registration failed\n");
+
+	ret = devm_iio_triggered_buffer_setup(indio_dev->dev.parent, indio_dev,
+					      NULL, bh1745_trigger_handler,
+					      NULL);
+	if (ret)
+		return dev_err_probe(&data->client->dev, ret,
+				     "Triggered buffer setup failed\n");
+
+	ret = devm_request_threaded_irq(&data->client->dev, data->client->irq,
+					NULL, bh1745_interrupt_handler,
+					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+					"bh1745_interrupt", indio_dev);
+	if (ret)
+		return dev_err_probe(&data->client->dev, ret,
+				     "Request for IRQ failed\n");
+
+	dev_info(&data->client->dev,
+		 "Triggered buffer and IRQ setup successfully");
+
+	return ret;
+}
+
+static int bh1745_init(struct bh1745_data *data)
+{
+	int ret;
+
+	mutex_init(&data->lock);
+	data->mode_ctrl1 = 0;
+	data->mode_ctrl2 = 0;
+	data->interrupt = 0;
+	data->int_src = BH1745_INT_SOURCE_RED;
+
+	ret = bh1745_reset(data);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Failed to reset sensor\n");
+		return ret;
+	}
+
+	ret = bh1745_power_on(data);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Failed to turn on sensor\n");
+		return ret;
+	}
+
+	return ret;
+}
+
+static int bh1745_probe(struct i2c_client *client)
+{
+	int ret;
+	struct bh1745_data *data;
+	struct iio_dev *indio_dev;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;
+	indio_dev->info = &bh1745_info;
+	indio_dev->name = "bh1745";
+	indio_dev->channels = bh1745_channels;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->num_channels = ARRAY_SIZE(bh1745_channels);
+
+	data->regmap = devm_regmap_init_i2c(client, &bh1745_regmap);
+	if (IS_ERR(data->regmap))
+		return dev_err_probe(&client->dev, PTR_ERR(data->regmap),
+				     "Failed to initialize Regmap\n");
+
+	ret = bh1745_init(data);
+	if (ret < 0)
+		return ret;
+
+	if (client->irq) {
+		ret = bh1745_setup_trigger(indio_dev);
+		if (ret < 0)
+			return ret;
+	}
+
+	ret = devm_iio_device_register(&client->dev, indio_dev);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Failed to register device\n");
+		return ret;
+	}
+
+	dev_info(&data->client->dev, "BH1745 driver loaded\n");
+
+	return ret;
+}
+
+static const struct i2c_device_id bh1745_idtable[] = {
+	{ "bh1745" },
+	{},
+};
+
+static const struct of_device_id bh1745_of_match[] = {
+	{
+		.compatible = "rohm,bh1745",
+	},
+	{},
+};
+
+MODULE_DEVICE_TABLE(i2c, bh1745_idtable);
+
+static struct i2c_driver bh1745_driver = {
+	.driver = {
+		.name = "bh1745",
+		.of_match_table = bh1745_of_match,
+	},
+	.probe = bh1745_probe,
+	.remove = bh1745_remove,
+	.id_table = bh1745_idtable,
+};
+
+module_i2c_driver(bh1745_driver);
+MODULE_AUTHOR("Mudit Sharma <muditsharma.info@gmail.com>");
+MODULE_DESCRIPTION("BH1745 colour sensor driver");
+MODULE_LICENSE("GPL");
-- 
2.43.0