ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

31 files changed, 10188 insertions, 0 deletions

diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig
new file mode 100644
index 000000000..b22afa1f6
--- /dev/null
+++ b/drivers/iio/chemical/Kconfig
@@ -0,0 +1,260 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Chemical sensors
+#
+
+menu "Chemical Sensors"
+
+config AOSONG_AGS02MA
+	tristate "Aosong AGS02MA TVOC sensor driver"
+	depends on I2C
+	select CRC8
+	help
+	  Say Y here to build support for Aosong AGS02MA TVOC (Total Volatile
+	  Organic Compounds) sensor.
+
+	  To compile this driver as module, choose M here: the module will be
+	  called ags02ma.
+
+config ATLAS_PH_SENSOR
+	tristate "Atlas Scientific OEM SM sensors"
+	depends on I2C
+	select REGMAP_I2C
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	select IRQ_WORK
+	help
+	  Say Y here to build I2C interface support for the following
+	  Atlas Scientific OEM SM sensors:
+	    * pH SM sensor
+	    * EC SM sensor
+	    * ORP SM sensor
+
+	  To compile this driver as module, choose M here: the
+	  module will be called atlas-ph-sensor.
+
+config ATLAS_EZO_SENSOR
+	tristate "Atlas Scientific EZO sensors"
+	depends on I2C
+	help
+	  Say Y here to build I2C interface support for the following
+	  Atlas Scientific EZO sensors
+	    * CO2 EZO Sensor
+
+	  To compile this driver as module, choose M here: the
+	  module will be called atlas-ezo-sensor.
+
+config BME680
+	tristate "Bosch Sensortec BME680 sensor driver"
+	depends on (I2C || SPI)
+	select REGMAP
+	select BME680_I2C if I2C
+	select BME680_SPI if SPI
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say yes here to build support for Bosch Sensortec BME680 sensor with
+	  temperature, pressure, humidity and gas sensing capability.
+
+	  This driver can also be built as a module. If so, the module for I2C
+	  would be called bme680_i2c and bme680_spi for SPI support.
+
+config BME680_I2C
+	tristate
+	depends on I2C && BME680
+	select REGMAP_I2C
+
+config BME680_SPI
+	tristate
+	depends on SPI && BME680
+	select REGMAP_SPI
+
+config CCS811
+	tristate "AMS CCS811 VOC sensor"
+	depends on I2C
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say Y here to build I2C interface support for the AMS
+	  CCS811 VOC (Volatile Organic Compounds) sensor
+
+config ENS160
+	tristate "ScioSense ENS160 sensor driver"
+	depends on (I2C || SPI)
+	select REGMAP
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	select ENS160_I2C if I2C
+	select ENS160_SPI if SPI
+	help
+	  Say yes here to build support for ScioSense ENS160 multi-gas sensor.
+
+	  This driver can also be built as a module. If so, the module for I2C
+	  would be called ens160_i2c and ens160_spi for SPI support.
+
+config ENS160_I2C
+	tristate
+	select REGMAP_I2C
+
+config ENS160_SPI
+	tristate
+	select REGMAP_SPI
+
+config IAQCORE
+	tristate "AMS iAQ-Core VOC sensors"
+	depends on I2C
+	help
+	  Say Y here to build I2C interface support for the AMS
+	  iAQ-Core Continuous/Pulsed VOC (Volatile Organic Compounds)
+	  sensors
+
+config MHZ19B
+	tristate "Winsen MHZ19B CO2 sensor"
+	depends on SERIAL_DEV_BUS
+	help
+	  Say Y here to build Serdev interface support for the Winsen
+	  MHZ19B CO2 sensor.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called mhz19b.
+
+config PMS7003
+	tristate "Plantower PMS7003 particulate matter sensor"
+	depends on SERIAL_DEV_BUS
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say Y here to build support for the Plantower PMS7003 particulate
+	  matter sensor.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called pms7003.
+
+config SCD30_CORE
+	tristate "SCD30 carbon dioxide sensor driver"
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say Y here to build support for the Sensirion SCD30 sensor with carbon
+	  dioxide, relative humidity and temperature sensing capabilities.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called scd30_core.
+
+config SCD30_I2C
+	tristate "SCD30 carbon dioxide sensor I2C driver"
+	depends on SCD30_CORE && I2C
+	select CRC8
+	help
+	  Say Y here to build support for the Sensirion SCD30 I2C interface
+	  driver.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called scd30_i2c.
+
+config SCD30_SERIAL
+	tristate "SCD30 carbon dioxide sensor serial driver"
+	depends on SCD30_CORE && SERIAL_DEV_BUS
+	select CRC16
+	help
+	  Say Y here to build support for the Sensirion SCD30 serial interface
+	  driver.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called scd30_serial.
+
+config SCD4X
+	tristate "SCD4X carbon dioxide sensor driver"
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	depends on I2C
+	select CRC8
+	help
+	  Say Y here to build support for the Sensirion SCD4X sensor with carbon
+	  dioxide, relative humidity and temperature sensing capabilities.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called scd4x.
+
+config SEN0322
+	tristate "SEN0322 oxygen sensor"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  Say Y here to build support for the DFRobot SEN0322 oxygen sensor.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called sen0322.
+
+config SENSIRION_SGP30
+	tristate "Sensirion SGPxx gas sensors"
+	depends on I2C
+	select CRC8
+	help
+	  Say Y here to build I2C interface support for the following
+	  Sensirion SGP gas sensors:
+	    * SGP30 gas sensor
+	    * SGPC3 low power gas sensor
+
+	  To compile this driver as module, choose M here: the
+	  module will be called sgp30.
+
+config SENSIRION_SGP40
+	tristate "Sensirion SGP40 gas sensor"
+	depends on I2C
+	select CRC8
+	help
+	  Say Y here to build I2C interface to support Sensirion SGP40 gas
+	  sensor
+
+	  To compile this driver as module, choose M here: the
+	  module will be called sgp40.
+
+config SPS30
+	tristate
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+
+config SPS30_I2C
+	tristate "SPS30 particulate matter sensor I2C driver"
+	depends on I2C
+	select SPS30
+	select CRC8
+	help
+	  Say Y here to build support for the Sensirion SPS30 I2C interface
+	  driver.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called sps30_i2c.
+
+config SPS30_SERIAL
+	tristate "SPS30 particulate matter sensor serial driver"
+	depends on SERIAL_DEV_BUS
+	select SPS30
+	help
+	  Say Y here to build support for the Sensirion SPS30 serial interface
+	  driver.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called sps30_serial.
+
+config SENSEAIR_SUNRISE_CO2
+	tristate "Senseair Sunrise 006-0-0007 CO2 sensor"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  Say yes here to build support for Senseair Sunrise 006-0-0007 CO2
+	  sensor.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called sunrise_co2.
+
+config VZ89X
+	tristate "SGX Sensortech MiCS VZ89X VOC sensor"
+	depends on I2C
+	help
+	  Say Y here to build I2C interface support for the SGX
+	  Sensortech MiCS VZ89X VOC (Volatile Organic Compounds)
+	  sensors
+
+endmenu
diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile
new file mode 100644
index 000000000..2287a00a6
--- /dev/null
+++ b/drivers/iio/chemical/Makefile
@@ -0,0 +1,31 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for IIO chemical sensors
+#
+
+# When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_AOSONG_AGS02MA)	+= ags02ma.o
+obj-$(CONFIG_ATLAS_PH_SENSOR)	+= atlas-sensor.o
+obj-$(CONFIG_ATLAS_EZO_SENSOR)	+= atlas-ezo-sensor.o
+obj-$(CONFIG_BME680) += bme680_core.o
+obj-$(CONFIG_BME680_I2C) += bme680_i2c.o
+obj-$(CONFIG_BME680_SPI) += bme680_spi.o
+obj-$(CONFIG_CCS811)		+= ccs811.o
+obj-$(CONFIG_ENS160) += ens160_core.o
+obj-$(CONFIG_ENS160_I2C) += ens160_i2c.o
+obj-$(CONFIG_ENS160_SPI) += ens160_spi.o
+obj-$(CONFIG_IAQCORE)		+= ams-iaq-core.o
+obj-$(CONFIG_MHZ19B) += mhz19b.o
+obj-$(CONFIG_PMS7003) += pms7003.o
+obj-$(CONFIG_SCD30_CORE) += scd30_core.o
+obj-$(CONFIG_SCD30_I2C) += scd30_i2c.o
+obj-$(CONFIG_SCD30_SERIAL) += scd30_serial.o
+obj-$(CONFIG_SCD4X) += scd4x.o
+obj-$(CONFIG_SEN0322)	+= sen0322.o
+obj-$(CONFIG_SENSEAIR_SUNRISE_CO2) += sunrise_co2.o
+obj-$(CONFIG_SENSIRION_SGP30)	+= sgp30.o
+obj-$(CONFIG_SENSIRION_SGP40)	+= sgp40.o
+obj-$(CONFIG_SPS30) += sps30.o
+obj-$(CONFIG_SPS30_I2C) += sps30_i2c.o
+obj-$(CONFIG_SPS30_SERIAL) += sps30_serial.o
+obj-$(CONFIG_VZ89X)		+= vz89x.o
diff --git a/drivers/iio/chemical/ags02ma.c b/drivers/iio/chemical/ags02ma.c
new file mode 100644
index 000000000..8b97ea4a9
--- /dev/null
+++ b/drivers/iio/chemical/ags02ma.c
@@ -0,0 +1,165 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2023 Anshul Dalal <anshulusr@gmail.com>
+ *
+ * Driver for Aosong AGS02MA
+ *
+ * Datasheet:
+ *   https://asairsensors.com/wp-content/uploads/2021/09/AGS02MA.pdf
+ * Product Page:
+ *   http://www.aosong.com/m/en/products-33.html
+ */
+
+#include <linux/crc8.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+
+#include <linux/iio/iio.h>
+
+#define AGS02MA_TVOC_READ_REG		   0x00
+#define AGS02MA_VERSION_REG		   0x11
+
+#define AGS02MA_VERSION_PROCESSING_DELAY   30
+#define AGS02MA_TVOC_READ_PROCESSING_DELAY 1500
+
+#define AGS02MA_CRC8_INIT		   0xff
+#define AGS02MA_CRC8_POLYNOMIAL		   0x31
+
+DECLARE_CRC8_TABLE(ags02ma_crc8_table);
+
+struct ags02ma_data {
+	struct i2c_client *client;
+};
+
+struct ags02ma_reading {
+	__be32 data;
+	u8 crc;
+} __packed;
+
+static int ags02ma_register_read(struct i2c_client *client, u8 reg, u16 delay,
+				 u32 *val)
+{
+	int ret;
+	u8 crc;
+	struct ags02ma_reading read_buffer;
+
+	ret = i2c_master_send(client, &reg, sizeof(reg));
+	if (ret < 0) {
+		dev_err(&client->dev,
+			"Failed to send data to register 0x%x: %d", reg, ret);
+		return ret;
+	}
+
+	/* Processing Delay, Check Table 7.7 in the datasheet */
+	msleep_interruptible(delay);
+
+	ret = i2c_master_recv(client, (u8 *)&read_buffer, sizeof(read_buffer));
+	if (ret < 0) {
+		dev_err(&client->dev,
+			"Failed to receive from register 0x%x: %d", reg, ret);
+		return ret;
+	}
+
+	crc = crc8(ags02ma_crc8_table, (u8 *)&read_buffer.data,
+		   sizeof(read_buffer.data), AGS02MA_CRC8_INIT);
+	if (crc != read_buffer.crc) {
+		dev_err(&client->dev, "CRC error\n");
+		return -EIO;
+	}
+
+	*val = be32_to_cpu(read_buffer.data);
+	return 0;
+}
+
+static int ags02ma_read_raw(struct iio_dev *iio_device,
+			    struct iio_chan_spec const *chan, int *val,
+			    int *val2, long mask)
+{
+	int ret;
+	struct ags02ma_data *data = iio_priv(iio_device);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = ags02ma_register_read(data->client, AGS02MA_TVOC_READ_REG,
+					    AGS02MA_TVOC_READ_PROCESSING_DELAY,
+					    val);
+		if (ret < 0)
+			return ret;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		/* The sensor reads data as ppb */
+		*val = 0;
+		*val2 = 100;
+		return IIO_VAL_INT_PLUS_NANO;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info ags02ma_info = {
+	.read_raw = ags02ma_read_raw,
+};
+
+static const struct iio_chan_spec ags02ma_channel = {
+	.type = IIO_CONCENTRATION,
+	.channel2 = IIO_MOD_VOC,
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+		BIT(IIO_CHAN_INFO_SCALE),
+};
+
+static int ags02ma_probe(struct i2c_client *client)
+{
+	int ret;
+	struct ags02ma_data *data;
+	struct iio_dev *indio_dev;
+	u32 version;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	crc8_populate_msb(ags02ma_crc8_table, AGS02MA_CRC8_POLYNOMIAL);
+
+	ret = ags02ma_register_read(client, AGS02MA_VERSION_REG,
+				    AGS02MA_VERSION_PROCESSING_DELAY, &version);
+	if (ret < 0)
+		return dev_err_probe(&client->dev, ret,
+			      "Failed to read device version\n");
+	dev_dbg(&client->dev, "Aosong AGS02MA, Version: 0x%x", version);
+
+	data = iio_priv(indio_dev);
+	data->client = client;
+	indio_dev->info = &ags02ma_info;
+	indio_dev->channels = &ags02ma_channel;
+	indio_dev->num_channels = 1;
+	indio_dev->name = "ags02ma";
+
+	return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static const struct i2c_device_id ags02ma_id_table[] = {
+	{ .name = "ags02ma" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ags02ma_id_table);
+
+static const struct of_device_id ags02ma_of_table[] = {
+	{ .compatible = "aosong,ags02ma" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ags02ma_of_table);
+
+static struct i2c_driver ags02ma_driver = {
+	.driver = {
+		.name = "ags02ma",
+		.of_match_table = ags02ma_of_table,
+	},
+	.id_table = ags02ma_id_table,
+	.probe = ags02ma_probe,
+};
+module_i2c_driver(ags02ma_driver);
+
+MODULE_AUTHOR("Anshul Dalal <anshulusr@gmail.com>");
+MODULE_DESCRIPTION("Aosong AGS02MA TVOC Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/iio/chemical/ams-iaq-core.c b/drivers/iio/chemical/ams-iaq-core.c
new file mode 100644
index 000000000..7af515110
--- /dev/null
+++ b/drivers/iio/chemical/ams-iaq-core.c
@@ -0,0 +1,188 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * ams-iaq-core.c - Support for AMS iAQ-Core VOC sensors
+ *
+ * Copyright (C) 2015, 2018
+ * Author: Matt Ranostay <matt.ranostay@konsulko.com>
+ */
+
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+
+#define AMS_IAQCORE_DATA_SIZE		9
+
+#define AMS_IAQCORE_VOC_CO2_IDX		0
+#define AMS_IAQCORE_VOC_RESISTANCE_IDX	1
+#define AMS_IAQCORE_VOC_TVOC_IDX	2
+
+struct ams_iaqcore_reading {
+	__be16 co2_ppm;
+	u8 status;
+	__be32 resistance;
+	__be16 voc_ppb;
+} __packed;
+
+struct ams_iaqcore_data {
+	struct i2c_client *client;
+	struct mutex lock;
+	unsigned long last_update;
+
+	struct ams_iaqcore_reading buffer;
+};
+
+static const struct iio_chan_spec ams_iaqcore_channels[] = {
+	{
+		.type = IIO_CONCENTRATION,
+		.channel2 = IIO_MOD_CO2,
+		.modified = 1,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+		.address = AMS_IAQCORE_VOC_CO2_IDX,
+	},
+	{
+		.type = IIO_RESISTANCE,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+		.address = AMS_IAQCORE_VOC_RESISTANCE_IDX,
+	},
+	{
+		.type = IIO_CONCENTRATION,
+		.channel2 = IIO_MOD_VOC,
+		.modified = 1,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+		.address = AMS_IAQCORE_VOC_TVOC_IDX,
+	},
+};
+
+static int ams_iaqcore_read_measurement(struct ams_iaqcore_data *data)
+{
+	struct i2c_client *client = data->client;
+	int ret;
+
+	struct i2c_msg msg = {
+		.addr = client->addr,
+		.flags = client->flags | I2C_M_RD,
+		.len = AMS_IAQCORE_DATA_SIZE,
+		.buf = (char *) &data->buffer,
+	};
+
+	ret = i2c_transfer(client->adapter, &msg, 1);
+
+	return (ret == AMS_IAQCORE_DATA_SIZE) ? 0 : ret;
+}
+
+static int ams_iaqcore_get_measurement(struct ams_iaqcore_data *data)
+{
+	int ret;
+
+	/* sensor can only be polled once a second max per datasheet */
+	if (!time_after(jiffies, data->last_update + HZ))
+		return 0;
+
+	ret = ams_iaqcore_read_measurement(data);
+	if (ret < 0)
+		return ret;
+
+	data->last_update = jiffies;
+
+	return 0;
+}
+
+static int ams_iaqcore_read_raw(struct iio_dev *indio_dev,
+				struct iio_chan_spec const *chan, int *val,
+				int *val2, long mask)
+{
+	struct ams_iaqcore_data *data = iio_priv(indio_dev);
+	int ret;
+
+	if (mask != IIO_CHAN_INFO_PROCESSED)
+		return -EINVAL;
+
+	mutex_lock(&data->lock);
+	ret = ams_iaqcore_get_measurement(data);
+
+	if (ret)
+		goto err_out;
+
+	switch (chan->address) {
+	case AMS_IAQCORE_VOC_CO2_IDX:
+		*val = 0;
+		*val2 = be16_to_cpu(data->buffer.co2_ppm);
+		ret = IIO_VAL_INT_PLUS_MICRO;
+		break;
+	case AMS_IAQCORE_VOC_RESISTANCE_IDX:
+		*val = be32_to_cpu(data->buffer.resistance);
+		ret = IIO_VAL_INT;
+		break;
+	case AMS_IAQCORE_VOC_TVOC_IDX:
+		*val = 0;
+		*val2 = be16_to_cpu(data->buffer.voc_ppb);
+		ret = IIO_VAL_INT_PLUS_NANO;
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+err_out:
+	mutex_unlock(&data->lock);
+
+	return ret;
+}
+
+static const struct iio_info ams_iaqcore_info = {
+	.read_raw	= ams_iaqcore_read_raw,
+};
+
+static int ams_iaqcore_probe(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev;
+	struct ams_iaqcore_data *data;
+
+	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;
+
+	/* so initial reading will complete */
+	data->last_update = jiffies - HZ;
+	mutex_init(&data->lock);
+
+	indio_dev->info = &ams_iaqcore_info;
+	indio_dev->name = dev_name(&client->dev);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	indio_dev->channels = ams_iaqcore_channels;
+	indio_dev->num_channels = ARRAY_SIZE(ams_iaqcore_channels);
+
+	return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static const struct i2c_device_id ams_iaqcore_id[] = {
+	{ .name = "ams-iaq-core" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ams_iaqcore_id);
+
+static const struct of_device_id ams_iaqcore_dt_ids[] = {
+	{ .compatible = "ams,iaq-core" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ams_iaqcore_dt_ids);
+
+static struct i2c_driver ams_iaqcore_driver = {
+	.driver = {
+		.name	= "ams-iaq-core",
+		.of_match_table = ams_iaqcore_dt_ids,
+	},
+	.probe = ams_iaqcore_probe,
+	.id_table = ams_iaqcore_id,
+};
+module_i2c_driver(ams_iaqcore_driver);
+
+MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
+MODULE_DESCRIPTION("AMS iAQ-Core VOC sensors");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/chemical/atlas-ezo-sensor.c b/drivers/iio/chemical/atlas-ezo-sensor.c
new file mode 100644
index 000000000..298b2fe48
--- /dev/null
+++ b/drivers/iio/chemical/atlas-ezo-sensor.c
@@ -0,0 +1,243 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * atlas-ezo-sensor.c - Support for Atlas Scientific EZO sensors
+ *
+ * Copyright (C) 2020 Konsulko Group
+ * Author: Matt Ranostay <matt.ranostay@konsulko.com>
+ */
+
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/property.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+
+#include <linux/iio/iio.h>
+
+#define ATLAS_EZO_DRV_NAME		"atlas-ezo-sensor"
+#define ATLAS_INT_TIME_IN_MS		950
+#define ATLAS_INT_HUM_TIME_IN_MS	350
+
+enum {
+	ATLAS_CO2_EZO,
+	ATLAS_O2_EZO,
+	ATLAS_HUM_EZO,
+};
+
+struct atlas_ezo_device {
+	const struct iio_chan_spec *channels;
+	int num_channels;
+	int delay;
+};
+
+struct atlas_ezo_data {
+	struct i2c_client *client;
+	const struct atlas_ezo_device *chip;
+
+	/* lock to avoid multiple concurrent read calls */
+	struct mutex lock;
+
+	u8 buffer[8];
+};
+
+#define ATLAS_CONCENTRATION_CHANNEL(_modifier) \
+	{ \
+		.type = IIO_CONCENTRATION, \
+		.modified = 1,\
+		.channel2 = _modifier, \
+		.info_mask_separate = \
+			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), \
+		.scan_index = 0, \
+		.scan_type =  { \
+			.sign = 'u', \
+			.realbits = 32, \
+			.storagebits = 32, \
+			.endianness = IIO_CPU, \
+		}, \
+	}
+
+static const struct iio_chan_spec atlas_co2_ezo_channels[] = {
+	ATLAS_CONCENTRATION_CHANNEL(IIO_MOD_CO2),
+};
+
+static const struct iio_chan_spec atlas_o2_ezo_channels[] = {
+	ATLAS_CONCENTRATION_CHANNEL(IIO_MOD_O2),
+};
+
+static const struct iio_chan_spec atlas_hum_ezo_channels[] = {
+	{
+		.type = IIO_HUMIDITYRELATIVE,
+		.info_mask_separate =
+			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+		.scan_index = 0,
+		.scan_type =  {
+			.sign = 'u',
+			.realbits = 32,
+			.storagebits = 32,
+			.endianness = IIO_CPU,
+		},
+	},
+};
+
+static const struct atlas_ezo_device atlas_ezo_devices[] = {
+	[ATLAS_CO2_EZO] = {
+		.channels = atlas_co2_ezo_channels,
+		.num_channels = 1,
+		.delay = ATLAS_INT_TIME_IN_MS,
+	},
+	[ATLAS_O2_EZO] = {
+		.channels = atlas_o2_ezo_channels,
+		.num_channels = 1,
+		.delay = ATLAS_INT_TIME_IN_MS,
+	},
+	[ATLAS_HUM_EZO] = {
+		.channels = atlas_hum_ezo_channels,
+		.num_channels = 1,
+		.delay = ATLAS_INT_HUM_TIME_IN_MS,
+	},
+};
+
+static void atlas_ezo_sanitize(char *buf)
+{
+	char *ptr = strchr(buf, '.');
+
+	if (!ptr)
+		return;
+
+	memmove(ptr, ptr + 1, strlen(ptr));
+}
+
+static int atlas_ezo_read_raw(struct iio_dev *indio_dev,
+			  struct iio_chan_spec const *chan,
+			  int *val, int *val2, long mask)
+{
+	struct atlas_ezo_data *data = iio_priv(indio_dev);
+	struct i2c_client *client = data->client;
+
+	if (chan->type != IIO_CONCENTRATION)
+		return -EINVAL;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW: {
+		int ret;
+		long tmp;
+
+		mutex_lock(&data->lock);
+
+		tmp = i2c_smbus_write_byte(client, 'R');
+
+		if (tmp < 0) {
+			mutex_unlock(&data->lock);
+			return tmp;
+		}
+
+		msleep(data->chip->delay);
+
+		tmp = i2c_master_recv(client, data->buffer, sizeof(data->buffer));
+
+		if (tmp < 0 || data->buffer[0] != 1) {
+			mutex_unlock(&data->lock);
+			return -EBUSY;
+		}
+
+		/* removing floating point for fixed number representation */
+		atlas_ezo_sanitize(data->buffer + 2);
+
+		ret = kstrtol(data->buffer + 1, 10, &tmp);
+
+		*val = tmp;
+
+		mutex_unlock(&data->lock);
+
+		return ret ? ret : IIO_VAL_INT;
+	}
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_HUMIDITYRELATIVE:
+			*val = 10;
+			return IIO_VAL_INT;
+		case IIO_CONCENTRATION:
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		/* IIO_CONCENTRATION modifiers */
+		switch (chan->channel2) {
+		case IIO_MOD_CO2:
+			*val = 0;
+			*val2 = 100; /* 0.0001 */
+			return IIO_VAL_INT_PLUS_MICRO;
+		case IIO_MOD_O2:
+			*val = 100;
+			return IIO_VAL_INT;
+		}
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct iio_info atlas_info = {
+	.read_raw = atlas_ezo_read_raw,
+};
+
+static const struct i2c_device_id atlas_ezo_id[] = {
+	{ .name = "atlas-co2-ezo", .driver_data = (kernel_ulong_t)&atlas_ezo_devices[ATLAS_CO2_EZO] },
+	{ .name = "atlas-o2-ezo", .driver_data = (kernel_ulong_t)&atlas_ezo_devices[ATLAS_O2_EZO] },
+	{ .name = "atlas-hum-ezo", .driver_data = (kernel_ulong_t)&atlas_ezo_devices[ATLAS_HUM_EZO] },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, atlas_ezo_id);
+
+static const struct of_device_id atlas_ezo_dt_ids[] = {
+	{ .compatible = "atlas,co2-ezo", .data = &atlas_ezo_devices[ATLAS_CO2_EZO], },
+	{ .compatible = "atlas,o2-ezo", .data = &atlas_ezo_devices[ATLAS_O2_EZO], },
+	{ .compatible = "atlas,hum-ezo", .data = &atlas_ezo_devices[ATLAS_HUM_EZO], },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, atlas_ezo_dt_ids);
+
+static int atlas_ezo_probe(struct i2c_client *client)
+{
+	const struct atlas_ezo_device *chip;
+	struct atlas_ezo_data *data;
+	struct iio_dev *indio_dev;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	chip = i2c_get_match_data(client);
+	if (!chip)
+		return -EINVAL;
+
+	indio_dev->info = &atlas_info;
+	indio_dev->name = ATLAS_EZO_DRV_NAME;
+	indio_dev->channels = chip->channels;
+	indio_dev->num_channels = chip->num_channels;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	data = iio_priv(indio_dev);
+	data->client = client;
+	data->chip = chip;
+	mutex_init(&data->lock);
+
+	return devm_iio_device_register(&client->dev, indio_dev);
+};
+
+static struct i2c_driver atlas_ezo_driver = {
+	.driver = {
+		.name	= ATLAS_EZO_DRV_NAME,
+		.of_match_table	= atlas_ezo_dt_ids,
+	},
+	.probe		= atlas_ezo_probe,
+	.id_table	= atlas_ezo_id,
+};
+module_i2c_driver(atlas_ezo_driver);
+
+MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
+MODULE_DESCRIPTION("Atlas Scientific EZO sensors");
+MODULE_LICENSE("GPL");
diff --git a/drivers/iio/chemical/atlas-sensor.c b/drivers/iio/chemical/atlas-sensor.c
new file mode 100644
index 000000000..1d4a9919d
--- /dev/null
+++ b/drivers/iio/chemical/atlas-sensor.c
@@ -0,0 +1,763 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * atlas-sensor.c - Support for Atlas Scientific OEM SM sensors
+ *
+ * Copyright (C) 2015-2019 Konsulko Group
+ * Author: Matt Ranostay <matt.ranostay@konsulko.com>
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/mutex.h>
+#include <linux/err.h>
+#include <linux/irq.h>
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/pm_runtime.h>
+
+#define ATLAS_DRV_NAME		"atlas"
+
+#define ATLAS_REG_DEV_TYPE		0x00
+#define ATLAS_REG_DEV_VERSION		0x01
+
+#define ATLAS_REG_INT_CONTROL		0x04
+#define ATLAS_REG_INT_CONTROL_EN	BIT(3)
+
+#define ATLAS_REG_PWR_CONTROL		0x06
+
+#define ATLAS_REG_PH_CALIB_STATUS	0x0d
+#define ATLAS_REG_PH_CALIB_STATUS_MASK	0x07
+#define ATLAS_REG_PH_CALIB_STATUS_LOW	BIT(0)
+#define ATLAS_REG_PH_CALIB_STATUS_MID	BIT(1)
+#define ATLAS_REG_PH_CALIB_STATUS_HIGH	BIT(2)
+
+#define ATLAS_REG_EC_CALIB_STATUS		0x0f
+#define ATLAS_REG_EC_CALIB_STATUS_MASK		0x0f
+#define ATLAS_REG_EC_CALIB_STATUS_DRY		BIT(0)
+#define ATLAS_REG_EC_CALIB_STATUS_SINGLE	BIT(1)
+#define ATLAS_REG_EC_CALIB_STATUS_LOW		BIT(2)
+#define ATLAS_REG_EC_CALIB_STATUS_HIGH		BIT(3)
+
+#define ATLAS_REG_DO_CALIB_STATUS		0x09
+#define ATLAS_REG_DO_CALIB_STATUS_MASK		0x03
+#define ATLAS_REG_DO_CALIB_STATUS_PRESSURE	BIT(0)
+#define ATLAS_REG_DO_CALIB_STATUS_DO		BIT(1)
+
+#define ATLAS_REG_RTD_DATA		0x0e
+
+#define ATLAS_REG_PH_TEMP_DATA		0x0e
+#define ATLAS_REG_PH_DATA		0x16
+
+#define ATLAS_REG_EC_PROBE		0x08
+#define ATLAS_REG_EC_TEMP_DATA		0x10
+#define ATLAS_REG_EC_DATA		0x18
+#define ATLAS_REG_TDS_DATA		0x1c
+#define ATLAS_REG_PSS_DATA		0x20
+
+#define ATLAS_REG_ORP_CALIB_STATUS	0x0d
+#define ATLAS_REG_ORP_DATA		0x0e
+
+#define ATLAS_REG_DO_TEMP_DATA		0x12
+#define ATLAS_REG_DO_DATA		0x22
+
+#define ATLAS_PH_INT_TIME_IN_MS		450
+#define ATLAS_EC_INT_TIME_IN_MS		650
+#define ATLAS_ORP_INT_TIME_IN_MS	450
+#define ATLAS_DO_INT_TIME_IN_MS		450
+#define ATLAS_RTD_INT_TIME_IN_MS	450
+
+enum {
+	ATLAS_PH_SM,
+	ATLAS_EC_SM,
+	ATLAS_ORP_SM,
+	ATLAS_DO_SM,
+	ATLAS_RTD_SM,
+};
+
+struct atlas_data {
+	struct i2c_client *client;
+	struct iio_trigger *trig;
+	const struct atlas_device *chip;
+	struct regmap *regmap;
+	unsigned int interrupt_enabled;
+	/* 96-bit data + 32-bit pad + 64-bit timestamp */
+	__be32 buffer[6] __aligned(8);
+};
+
+static const struct regmap_config atlas_regmap_config = {
+	.name = "atlas_regmap",
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static int atlas_buffer_num_channels(const struct iio_chan_spec *spec)
+{
+	int idx = 0;
+
+	for (; spec->type != IIO_TIMESTAMP; spec++)
+		idx++;
+
+	return idx;
+};
+
+static const struct iio_chan_spec atlas_ph_channels[] = {
+	{
+		.type = IIO_PH,
+		.address = ATLAS_REG_PH_DATA,
+		.info_mask_separate =
+			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+		.scan_index = 0,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 32,
+			.storagebits = 32,
+			.endianness = IIO_BE,
+		},
+	},
+	IIO_CHAN_SOFT_TIMESTAMP(1),
+	{
+		.type = IIO_TEMP,
+		.address = ATLAS_REG_PH_TEMP_DATA,
+		.info_mask_separate =
+			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+		.output = 1,
+		.scan_index = -1
+	},
+};
+
+#define ATLAS_CONCENTRATION_CHANNEL(_idx, _addr) \
+	{\
+		.type = IIO_CONCENTRATION, \
+		.indexed = 1, \
+		.channel = _idx, \
+		.address = _addr, \
+		.info_mask_separate = \
+			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), \
+		.scan_index = _idx + 1, \
+		.scan_type = { \
+			.sign = 'u', \
+			.realbits = 32, \
+			.storagebits = 32, \
+			.endianness = IIO_BE, \
+		}, \
+	}
+
+static const struct iio_chan_spec atlas_ec_channels[] = {
+	{
+		.type = IIO_ELECTRICALCONDUCTIVITY,
+		.address = ATLAS_REG_EC_DATA,
+		.info_mask_separate =
+			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+		.scan_index = 0,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 32,
+			.storagebits = 32,
+			.endianness = IIO_BE,
+		},
+	},
+	ATLAS_CONCENTRATION_CHANNEL(0, ATLAS_REG_TDS_DATA),
+	ATLAS_CONCENTRATION_CHANNEL(1, ATLAS_REG_PSS_DATA),
+	IIO_CHAN_SOFT_TIMESTAMP(3),
+	{
+		.type = IIO_TEMP,
+		.address = ATLAS_REG_EC_TEMP_DATA,
+		.info_mask_separate =
+			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+		.output = 1,
+		.scan_index = -1
+	},
+};
+
+static const struct iio_chan_spec atlas_orp_channels[] = {
+	{
+		.type = IIO_VOLTAGE,
+		.address = ATLAS_REG_ORP_DATA,
+		.info_mask_separate =
+			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+		.scan_index = 0,
+		.scan_type = {
+			.sign = 's',
+			.realbits = 32,
+			.storagebits = 32,
+			.endianness = IIO_BE,
+		},
+	},
+	IIO_CHAN_SOFT_TIMESTAMP(1),
+};
+
+static const struct iio_chan_spec atlas_do_channels[] = {
+	{
+		.type = IIO_CONCENTRATION,
+		.address = ATLAS_REG_DO_DATA,
+		.info_mask_separate =
+			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+		.scan_index = 0,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 32,
+			.storagebits = 32,
+			.endianness = IIO_BE,
+		},
+	},
+	IIO_CHAN_SOFT_TIMESTAMP(1),
+	{
+		.type = IIO_TEMP,
+		.address = ATLAS_REG_DO_TEMP_DATA,
+		.info_mask_separate =
+			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+		.output = 1,
+		.scan_index = -1
+	},
+};
+
+static const struct iio_chan_spec atlas_rtd_channels[] = {
+	{
+		.type = IIO_TEMP,
+		.address = ATLAS_REG_RTD_DATA,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+		.scan_index = 0,
+		.scan_type = {
+			.sign = 's',
+			.realbits = 32,
+			.storagebits = 32,
+			.endianness = IIO_BE,
+		},
+	},
+	IIO_CHAN_SOFT_TIMESTAMP(1),
+};
+
+static int atlas_check_ph_calibration(struct atlas_data *data)
+{
+	struct device *dev = &data->client->dev;
+	int ret;
+	unsigned int val;
+
+	ret = regmap_read(data->regmap, ATLAS_REG_PH_CALIB_STATUS, &val);
+	if (ret)
+		return ret;
+
+	if (!(val & ATLAS_REG_PH_CALIB_STATUS_MASK)) {
+		dev_warn(dev, "device has not been calibrated\n");
+		return 0;
+	}
+
+	if (!(val & ATLAS_REG_PH_CALIB_STATUS_LOW))
+		dev_warn(dev, "device missing low point calibration\n");
+
+	if (!(val & ATLAS_REG_PH_CALIB_STATUS_MID))
+		dev_warn(dev, "device missing mid point calibration\n");
+
+	if (!(val & ATLAS_REG_PH_CALIB_STATUS_HIGH))
+		dev_warn(dev, "device missing high point calibration\n");
+
+	return 0;
+}
+
+static int atlas_check_ec_calibration(struct atlas_data *data)
+{
+	struct device *dev = &data->client->dev;
+	int ret;
+	unsigned int val;
+	__be16	rval;
+
+	ret = regmap_bulk_read(data->regmap, ATLAS_REG_EC_PROBE, &rval, 2);
+	if (ret)
+		return ret;
+
+	val = be16_to_cpu(rval);
+	dev_info(dev, "probe set to K = %d.%.2d", val / 100, val % 100);
+
+	ret = regmap_read(data->regmap, ATLAS_REG_EC_CALIB_STATUS, &val);
+	if (ret)
+		return ret;
+
+	if (!(val & ATLAS_REG_EC_CALIB_STATUS_MASK)) {
+		dev_warn(dev, "device has not been calibrated\n");
+		return 0;
+	}
+
+	if (!(val & ATLAS_REG_EC_CALIB_STATUS_DRY))
+		dev_warn(dev, "device missing dry point calibration\n");
+
+	if (val & ATLAS_REG_EC_CALIB_STATUS_SINGLE) {
+		dev_warn(dev, "device using single point calibration\n");
+	} else {
+		if (!(val & ATLAS_REG_EC_CALIB_STATUS_LOW))
+			dev_warn(dev, "device missing low point calibration\n");
+
+		if (!(val & ATLAS_REG_EC_CALIB_STATUS_HIGH))
+			dev_warn(dev, "device missing high point calibration\n");
+	}
+
+	return 0;
+}
+
+static int atlas_check_orp_calibration(struct atlas_data *data)
+{
+	struct device *dev = &data->client->dev;
+	int ret;
+	unsigned int val;
+
+	ret = regmap_read(data->regmap, ATLAS_REG_ORP_CALIB_STATUS, &val);
+	if (ret)
+		return ret;
+
+	if (!val)
+		dev_warn(dev, "device has not been calibrated\n");
+
+	return 0;
+}
+
+static int atlas_check_do_calibration(struct atlas_data *data)
+{
+	struct device *dev = &data->client->dev;
+	int ret;
+	unsigned int val;
+
+	ret = regmap_read(data->regmap, ATLAS_REG_DO_CALIB_STATUS, &val);
+	if (ret)
+		return ret;
+
+	if (!(val & ATLAS_REG_DO_CALIB_STATUS_MASK)) {
+		dev_warn(dev, "device has not been calibrated\n");
+		return 0;
+	}
+
+	if (!(val & ATLAS_REG_DO_CALIB_STATUS_PRESSURE))
+		dev_warn(dev, "device missing atmospheric pressure calibration\n");
+
+	if (!(val & ATLAS_REG_DO_CALIB_STATUS_DO))
+		dev_warn(dev, "device missing dissolved oxygen calibration\n");
+
+	return 0;
+}
+
+struct atlas_device {
+	const struct iio_chan_spec *channels;
+	int num_channels;
+	int data_reg;
+
+	int (*calibration)(struct atlas_data *data);
+	int delay;
+};
+
+static const struct atlas_device atlas_devices[] = {
+	[ATLAS_PH_SM] = {
+				.channels = atlas_ph_channels,
+				.num_channels = 3,
+				.data_reg = ATLAS_REG_PH_DATA,
+				.calibration = &atlas_check_ph_calibration,
+				.delay = ATLAS_PH_INT_TIME_IN_MS,
+	},
+	[ATLAS_EC_SM] = {
+				.channels = atlas_ec_channels,
+				.num_channels = 5,
+				.data_reg = ATLAS_REG_EC_DATA,
+				.calibration = &atlas_check_ec_calibration,
+				.delay = ATLAS_EC_INT_TIME_IN_MS,
+	},
+	[ATLAS_ORP_SM] = {
+				.channels = atlas_orp_channels,
+				.num_channels = 2,
+				.data_reg = ATLAS_REG_ORP_DATA,
+				.calibration = &atlas_check_orp_calibration,
+				.delay = ATLAS_ORP_INT_TIME_IN_MS,
+	},
+	[ATLAS_DO_SM] = {
+				.channels = atlas_do_channels,
+				.num_channels = 3,
+				.data_reg = ATLAS_REG_DO_DATA,
+				.calibration = &atlas_check_do_calibration,
+				.delay = ATLAS_DO_INT_TIME_IN_MS,
+	},
+	[ATLAS_RTD_SM] = {
+				.channels = atlas_rtd_channels,
+				.num_channels = 2,
+				.data_reg = ATLAS_REG_RTD_DATA,
+				.delay = ATLAS_RTD_INT_TIME_IN_MS,
+	},
+};
+
+static int atlas_set_powermode(struct atlas_data *data, int on)
+{
+	return regmap_write(data->regmap, ATLAS_REG_PWR_CONTROL, on);
+}
+
+static int atlas_set_interrupt(struct atlas_data *data, bool state)
+{
+	if (!data->interrupt_enabled)
+		return 0;
+
+	return regmap_update_bits(data->regmap, ATLAS_REG_INT_CONTROL,
+				  ATLAS_REG_INT_CONTROL_EN,
+				  state ? ATLAS_REG_INT_CONTROL_EN : 0);
+}
+
+static int atlas_buffer_postenable(struct iio_dev *indio_dev)
+{
+	struct atlas_data *data = iio_priv(indio_dev);
+	int ret;
+
+	ret = pm_runtime_resume_and_get(&data->client->dev);
+	if (ret)
+		return ret;
+
+	ret = atlas_set_interrupt(data, true);
+	if (ret)
+		pm_runtime_put_autosuspend(&data->client->dev);
+
+	return ret;
+}
+
+static int atlas_buffer_predisable(struct iio_dev *indio_dev)
+{
+	struct atlas_data *data = iio_priv(indio_dev);
+	int ret;
+
+	ret = atlas_set_interrupt(data, false);
+	if (ret)
+		return ret;
+
+	ret = pm_runtime_put_autosuspend(&data->client->dev);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static const struct iio_buffer_setup_ops atlas_buffer_setup_ops = {
+	.postenable = atlas_buffer_postenable,
+	.predisable = atlas_buffer_predisable,
+};
+
+static irqreturn_t atlas_trigger_handler(int irq, void *private)
+{
+	struct iio_poll_func *pf = private;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct atlas_data *data = iio_priv(indio_dev);
+	int channels = atlas_buffer_num_channels(data->chip->channels);
+	int ret;
+
+	ret = regmap_bulk_read(data->regmap, data->chip->data_reg,
+			      &data->buffer, sizeof(__be32) * channels);
+
+	if (!ret)
+		iio_push_to_buffers_with_ts(indio_dev, data->buffer,
+					    sizeof(data->buffer),
+					    iio_get_time_ns(indio_dev));
+
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t atlas_interrupt_handler(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct atlas_data *data = iio_priv(indio_dev);
+
+	iio_trigger_poll_nested(data->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int atlas_read_measurement(struct atlas_data *data, int reg, __be32 *val)
+{
+	struct device *dev = &data->client->dev;
+	int suspended = pm_runtime_suspended(dev);
+	int ret;
+
+	ret = pm_runtime_resume_and_get(dev);
+	if (ret)
+		return ret;
+
+	if (suspended)
+		msleep(data->chip->delay);
+
+	ret = regmap_bulk_read(data->regmap, reg, val, sizeof(*val));
+
+	pm_runtime_put_autosuspend(dev);
+
+	return ret;
+}
+
+static int atlas_read_raw(struct iio_dev *indio_dev,
+			  struct iio_chan_spec const *chan,
+			  int *val, int *val2, long mask)
+{
+	struct atlas_data *data = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_PROCESSED:
+	case IIO_CHAN_INFO_RAW: {
+		int ret;
+		__be32 reg;
+
+		switch (chan->type) {
+		case IIO_TEMP:
+			ret = regmap_bulk_read(data->regmap, chan->address,
+					       &reg, sizeof(reg));
+			break;
+		case IIO_PH:
+		case IIO_CONCENTRATION:
+		case IIO_ELECTRICALCONDUCTIVITY:
+		case IIO_VOLTAGE:
+			if (!iio_device_claim_direct(indio_dev))
+				return -EBUSY;
+
+			ret = atlas_read_measurement(data, chan->address, &reg);
+
+			iio_device_release_direct(indio_dev);
+			break;
+		default:
+			ret = -EINVAL;
+		}
+
+		if (!ret) {
+			*val = be32_to_cpu(reg);
+			ret = IIO_VAL_INT;
+		}
+		return ret;
+	}
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_TEMP:
+			*val = 10;
+			return IIO_VAL_INT;
+		case IIO_PH:
+			*val = 1; /* 0.001 */
+			*val2 = 1000;
+			break;
+		case IIO_ELECTRICALCONDUCTIVITY:
+			*val = 1; /* 0.00001 */
+			*val2 = 100000;
+			break;
+		case IIO_CONCENTRATION:
+			*val = 0; /* 0.000000001 */
+			*val2 = 1000;
+			return IIO_VAL_INT_PLUS_NANO;
+		case IIO_VOLTAGE:
+			*val = 1; /* 0.1 */
+			*val2 = 10;
+			break;
+		default:
+			return -EINVAL;
+		}
+		return IIO_VAL_FRACTIONAL;
+	}
+
+	return -EINVAL;
+}
+
+static int atlas_write_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int val, int val2, long mask)
+{
+	struct atlas_data *data = iio_priv(indio_dev);
+	__be32 reg = cpu_to_be32(val / 10);
+
+	if (val2 != 0 || val < 0 || val > 20000)
+		return -EINVAL;
+
+	if (mask != IIO_CHAN_INFO_RAW || chan->type != IIO_TEMP)
+		return -EINVAL;
+
+	return regmap_bulk_write(data->regmap, chan->address,
+				 &reg, sizeof(reg));
+}
+
+static const struct iio_info atlas_info = {
+	.read_raw = atlas_read_raw,
+	.write_raw = atlas_write_raw,
+};
+
+static const struct i2c_device_id atlas_id[] = {
+	{ .name = "atlas-ph-sm", .driver_data = (kernel_ulong_t)&atlas_devices[ATLAS_PH_SM] },
+	{ .name = "atlas-ec-sm", .driver_data = (kernel_ulong_t)&atlas_devices[ATLAS_EC_SM] },
+	{ .name = "atlas-orp-sm", .driver_data = (kernel_ulong_t)&atlas_devices[ATLAS_ORP_SM] },
+	{ .name = "atlas-do-sm", .driver_data = (kernel_ulong_t)&atlas_devices[ATLAS_DO_SM] },
+	{ .name = "atlas-rtd-sm", .driver_data = (kernel_ulong_t)&atlas_devices[ATLAS_RTD_SM] },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, atlas_id);
+
+static const struct of_device_id atlas_dt_ids[] = {
+	{ .compatible = "atlas,ph-sm", .data = &atlas_devices[ATLAS_PH_SM] },
+	{ .compatible = "atlas,ec-sm", .data = &atlas_devices[ATLAS_EC_SM] },
+	{ .compatible = "atlas,orp-sm", .data = &atlas_devices[ATLAS_ORP_SM] },
+	{ .compatible = "atlas,do-sm", .data = &atlas_devices[ATLAS_DO_SM] },
+	{ .compatible = "atlas,rtd-sm", .data = &atlas_devices[ATLAS_RTD_SM] },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, atlas_dt_ids);
+
+static int atlas_probe(struct i2c_client *client)
+{
+	struct atlas_data *data;
+	const struct atlas_device *chip;
+	struct iio_trigger *trig;
+	struct iio_dev *indio_dev;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	chip = i2c_get_match_data(client);
+
+	indio_dev->info = &atlas_info;
+	indio_dev->name = ATLAS_DRV_NAME;
+	indio_dev->channels = chip->channels;
+	indio_dev->num_channels = chip->num_channels;
+	indio_dev->modes = INDIO_BUFFER_SOFTWARE | INDIO_DIRECT_MODE;
+
+	trig = devm_iio_trigger_alloc(&client->dev, "%s-dev%d",
+				      indio_dev->name, iio_device_id(indio_dev));
+
+	if (!trig)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	data->client = client;
+	data->trig = trig;
+	data->chip = chip;
+	iio_trigger_set_drvdata(trig, indio_dev);
+
+	i2c_set_clientdata(client, indio_dev);
+
+	data->regmap = devm_regmap_init_i2c(client, &atlas_regmap_config);
+	if (IS_ERR(data->regmap)) {
+		dev_err(&client->dev, "regmap initialization failed\n");
+		return PTR_ERR(data->regmap);
+	}
+
+	ret = pm_runtime_set_active(&client->dev);
+	if (ret)
+		return ret;
+
+	ret = chip->calibration(data);
+	if (ret)
+		return ret;
+
+	ret = iio_trigger_register(trig);
+	if (ret) {
+		dev_err(&client->dev, "failed to register trigger\n");
+		return ret;
+	}
+
+	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
+		&atlas_trigger_handler, &atlas_buffer_setup_ops);
+	if (ret) {
+		dev_err(&client->dev, "cannot setup iio trigger\n");
+		goto unregister_trigger;
+	}
+
+	if (client->irq > 0) {
+		/* interrupt pin toggles on new conversion */
+		ret = devm_request_threaded_irq(&client->dev, client->irq,
+				NULL, atlas_interrupt_handler,
+				IRQF_TRIGGER_RISING |
+				IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+				"atlas_irq",
+				indio_dev);
+
+		if (ret)
+			dev_warn(&client->dev,
+				"request irq (%d) failed\n", client->irq);
+		else
+			data->interrupt_enabled = 1;
+	}
+
+	ret = atlas_set_powermode(data, 1);
+	if (ret) {
+		dev_err(&client->dev, "cannot power device on");
+		goto unregister_buffer;
+	}
+
+	pm_runtime_enable(&client->dev);
+	pm_runtime_set_autosuspend_delay(&client->dev, 2500);
+	pm_runtime_use_autosuspend(&client->dev);
+
+	ret = iio_device_register(indio_dev);
+	if (ret) {
+		dev_err(&client->dev, "unable to register device\n");
+		goto unregister_pm;
+	}
+
+	return 0;
+
+unregister_pm:
+	pm_runtime_disable(&client->dev);
+	atlas_set_powermode(data, 0);
+
+unregister_buffer:
+	iio_triggered_buffer_cleanup(indio_dev);
+
+unregister_trigger:
+	iio_trigger_unregister(data->trig);
+
+	return ret;
+}
+
+static void atlas_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct atlas_data *data = iio_priv(indio_dev);
+	int ret;
+
+	iio_device_unregister(indio_dev);
+	iio_triggered_buffer_cleanup(indio_dev);
+	iio_trigger_unregister(data->trig);
+
+	pm_runtime_disable(&client->dev);
+	pm_runtime_set_suspended(&client->dev);
+
+	ret = atlas_set_powermode(data, 0);
+	if (ret)
+		dev_err(&client->dev, "Failed to power down device (%pe)\n",
+			ERR_PTR(ret));
+}
+
+static int atlas_runtime_suspend(struct device *dev)
+{
+	struct atlas_data *data =
+		     iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
+
+	return atlas_set_powermode(data, 0);
+}
+
+static int atlas_runtime_resume(struct device *dev)
+{
+	struct atlas_data *data =
+		     iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
+
+	return atlas_set_powermode(data, 1);
+}
+
+static const struct dev_pm_ops atlas_pm_ops = {
+	RUNTIME_PM_OPS(atlas_runtime_suspend, atlas_runtime_resume, NULL)
+};
+
+static struct i2c_driver atlas_driver = {
+	.driver = {
+		.name	= ATLAS_DRV_NAME,
+		.of_match_table	= atlas_dt_ids,
+		.pm	= pm_ptr(&atlas_pm_ops),
+	},
+	.probe		= atlas_probe,
+	.remove		= atlas_remove,
+	.id_table	= atlas_id,
+};
+module_i2c_driver(atlas_driver);
+
+MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
+MODULE_DESCRIPTION("Atlas Scientific SM sensors");
+MODULE_LICENSE("GPL");
diff --git a/drivers/iio/chemical/bme680.h b/drivers/iio/chemical/bme680.h
new file mode 100644
index 000000000..7d86ed8b0
--- /dev/null
+++ b/drivers/iio/chemical/bme680.h
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef BME680_H_
+#define BME680_H_
+
+#include <linux/pm.h>
+#include <linux/regmap.h>
+
+#define BME680_REG_CHIP_ID			0xD0
+#define   BME680_CHIP_ID_VAL			0x61
+#define BME680_REG_SOFT_RESET			0xE0
+#define   BME680_CMD_SOFTRESET			0xB6
+#define BME680_REG_STATUS			0x73
+#define   BME680_SPI_MEM_PAGE_BIT		BIT(4)
+#define     BME680_SPI_MEM_PAGE_1_VAL		1
+
+#define BME680_REG_TEMP_MSB			0x22
+#define BME680_REG_PRESS_MSB			0x1F
+#define BME680_REG_HUMIDITY_MSB			0x25
+#define BME680_REG_GAS_MSB			0x2A
+#define BME680_REG_GAS_R_LSB			0x2B
+#define   BME680_GAS_STAB_BIT			BIT(4)
+#define   BME680_GAS_RANGE_MASK			GENMASK(3, 0)
+
+#define BME680_REG_CTRL_HUMIDITY		0x72
+#define   BME680_OSRS_HUMIDITY_MASK		GENMASK(2, 0)
+
+#define BME680_REG_CTRL_MEAS			0x74
+#define   BME680_OSRS_TEMP_MASK			GENMASK(7, 5)
+#define   BME680_OSRS_PRESS_MASK		GENMASK(4, 2)
+#define   BME680_MODE_MASK			GENMASK(1, 0)
+
+#define BME680_REG_CONFIG			0x75
+#define   BME680_FILTER_MASK			GENMASK(4, 2)
+#define     BME680_FILTER_COEFF_VAL		BIT(1)
+
+/* TEMP/PRESS/HUMID reading skipped */
+#define BME680_MEAS_SKIPPED			0x8000
+
+#define BME680_MAX_OVERFLOW_VAL			0x40000000
+#define BME680_HUM_REG_SHIFT_VAL		4
+#define BME680_BIT_H1_DATA_MASK			GENMASK(3, 0)
+
+#define   BME680_RHRANGE_MASK			GENMASK(5, 4)
+#define BME680_REG_RES_HEAT_VAL			0x00
+#define   BME680_RSERROR_MASK			GENMASK(7, 4)
+#define BME680_REG_IDAC_HEAT_0			0x50
+#define BME680_REG_RES_HEAT_0			0x5A
+#define BME680_REG_GAS_WAIT_0			0x64
+#define BME680_ADC_GAS_RES			GENMASK(15, 6)
+#define BME680_AMB_TEMP				25
+
+#define BME680_REG_CTRL_GAS_1			0x71
+#define   BME680_RUN_GAS_MASK			BIT(4)
+#define   BME680_NB_CONV_MASK			GENMASK(3, 0)
+
+#define BME680_REG_MEAS_STAT_0			0x1D
+#define   BME680_NEW_DATA_BIT			BIT(7)
+#define   BME680_GAS_MEAS_BIT			BIT(6)
+#define   BME680_MEAS_BIT			BIT(5)
+
+#define BME680_TEMP_NUM_BYTES			3
+#define BME680_PRESS_NUM_BYTES			3
+#define BME680_HUMID_NUM_BYTES			2
+#define BME680_GAS_NUM_BYTES			2
+
+#define BME680_MEAS_TRIM_MASK			GENMASK(24, 4)
+
+/* Datasheet Section 1.1, Table 1 */
+#define BME680_STARTUP_TIME_US			2000
+
+#define BME680_NUM_CHANNELS			4
+#define BME680_NUM_BULK_READ_REGS		15
+
+/* Calibration Parameters */
+#define BME680_T2_LSB_REG	0x8A
+#define BME680_H2_MSB_REG	0xE1
+#define BME680_GH3_REG		0xEE
+
+#define BME680_CALIB_RANGE_1_LEN               23
+#define BME680_CALIB_RANGE_2_LEN               14
+#define BME680_CALIB_RANGE_3_LEN               5
+
+extern const struct regmap_config bme680_regmap_config;
+extern const struct dev_pm_ops bme680_dev_pm_ops;
+
+int bme680_core_probe(struct device *dev, struct regmap *regmap,
+		      const char *name);
+
+#endif  /* BME680_H_ */
diff --git a/drivers/iio/chemical/bme680_core.c b/drivers/iio/chemical/bme680_core.c
new file mode 100644
index 000000000..ac9a73748
--- /dev/null
+++ b/drivers/iio/chemical/bme680_core.c
@@ -0,0 +1,1266 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Bosch BME680 - Temperature, Pressure, Humidity & Gas Sensor
+ *
+ * Copyright (C) 2017 - 2018 Bosch Sensortec GmbH
+ * Copyright (C) 2018 Himanshu Jha <himanshujha199640@gmail.com>
+ *
+ * Datasheet:
+ * https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BME680-DS001-00.pdf
+ */
+#include <linux/bitfield.h>
+#include <linux/cleanup.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/log2.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#include <linux/unaligned.h>
+
+#include "bme680.h"
+
+/* 1st set of calibration data */
+enum {
+	/* Temperature calib indexes */
+	T2_LSB = 0,
+	T3 = 2,
+	/* Pressure calib indexes */
+	P1_LSB = 4,
+	P2_LSB = 6,
+	P3 = 8,
+	P4_LSB = 10,
+	P5_LSB = 12,
+	P7 = 14,
+	P6 = 15,
+	P8_LSB = 18,
+	P9_LSB = 20,
+	P10 = 22,
+};
+
+/* 2nd set of calibration data */
+enum {
+	/* Humidity calib indexes */
+	H2_MSB = 0,
+	H1_LSB = 1,
+	H3 = 3,
+	H4 = 4,
+	H5 = 5,
+	H6 = 6,
+	H7 = 7,
+	/* Stray T1 calib index */
+	T1_LSB = 8,
+	/* Gas heater calib indexes */
+	GH2_LSB = 10,
+	GH1 = 12,
+	GH3 = 13,
+};
+
+/* 3rd set of calibration data */
+enum {
+	RES_HEAT_VAL = 0,
+	RES_HEAT_RANGE = 2,
+	RANGE_SW_ERR = 4,
+};
+
+struct bme680_calib {
+	u16 par_t1;
+	s16 par_t2;
+	s8  par_t3;
+	u16 par_p1;
+	s16 par_p2;
+	s8  par_p3;
+	s16 par_p4;
+	s16 par_p5;
+	s8  par_p6;
+	s8  par_p7;
+	s16 par_p8;
+	s16 par_p9;
+	u8  par_p10;
+	u16 par_h1;
+	u16 par_h2;
+	s8  par_h3;
+	s8  par_h4;
+	s8  par_h5;
+	u8  par_h6;
+	s8  par_h7;
+	s8  par_gh1;
+	s16 par_gh2;
+	s8  par_gh3;
+	u8  res_heat_range;
+	s8  res_heat_val;
+	s8  range_sw_err;
+};
+
+/* values of CTRL_MEAS register */
+enum bme680_op_mode {
+	BME680_MODE_SLEEP = 0,
+	BME680_MODE_FORCED = 1,
+};
+
+enum bme680_scan {
+	BME680_TEMP,
+	BME680_PRESS,
+	BME680_HUMID,
+	BME680_GAS,
+};
+
+static const char *const bme680_supply_names[] = { "vdd", "vddio" };
+
+struct bme680_data {
+	struct regmap *regmap;
+	struct bme680_calib bme680;
+	struct mutex lock; /* Protect multiple serial R/W ops to device. */
+	u8 oversampling_temp;
+	u8 oversampling_press;
+	u8 oversampling_humid;
+	u8 preheat_curr_mA;
+	u16 heater_dur;
+	u16 heater_temp;
+
+	struct {
+		s32 chan[BME680_NUM_CHANNELS];
+		aligned_s64 ts;
+	} scan;
+
+	union {
+		u8 buf[BME680_NUM_BULK_READ_REGS];
+		unsigned int check;
+		__be16 be16;
+		u8 bme680_cal_buf_1[BME680_CALIB_RANGE_1_LEN];
+		u8 bme680_cal_buf_2[BME680_CALIB_RANGE_2_LEN];
+		u8 bme680_cal_buf_3[BME680_CALIB_RANGE_3_LEN];
+	};
+};
+
+static const struct regmap_range bme680_volatile_ranges[] = {
+	regmap_reg_range(BME680_REG_MEAS_STAT_0, BME680_REG_GAS_R_LSB),
+	regmap_reg_range(BME680_REG_STATUS, BME680_REG_STATUS),
+	regmap_reg_range(BME680_T2_LSB_REG, BME680_GH3_REG),
+};
+
+static const struct regmap_access_table bme680_volatile_table = {
+	.yes_ranges	= bme680_volatile_ranges,
+	.n_yes_ranges	= ARRAY_SIZE(bme680_volatile_ranges),
+};
+
+const struct regmap_config bme680_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0xef,
+	.volatile_table = &bme680_volatile_table,
+	.cache_type = REGCACHE_MAPLE,
+};
+EXPORT_SYMBOL_NS(bme680_regmap_config, "IIO_BME680");
+
+static const struct iio_chan_spec bme680_channels[] = {
+	{
+		.type = IIO_TEMP,
+		/* PROCESSED maintained for ABI backwards compatibility */
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+				      BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE) |
+				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+		.scan_index = 0,
+		.scan_type = {
+			.sign = 's',
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_CPU,
+		},
+	},
+	{
+		.type = IIO_PRESSURE,
+		/* PROCESSED maintained for ABI backwards compatibility */
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+				      BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE) |
+				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+		.scan_index = 1,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 32,
+			.storagebits = 32,
+			.endianness = IIO_CPU,
+		},
+	},
+	{
+		.type = IIO_HUMIDITYRELATIVE,
+		/* PROCESSED maintained for ABI backwards compatibility */
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+				      BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE) |
+				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+		.scan_index = 2,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 32,
+			.storagebits = 32,
+			.endianness = IIO_CPU,
+		},
+	},
+	{
+		.type = IIO_RESISTANCE,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+		.scan_index = 3,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 32,
+			.storagebits = 32,
+			.endianness = IIO_CPU,
+		},
+	},
+	IIO_CHAN_SOFT_TIMESTAMP(4),
+	{
+		.type = IIO_CURRENT,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+		.output = 1,
+		.scan_index = -1,
+	},
+};
+
+static int bme680_read_calib(struct bme680_data *data,
+			     struct bme680_calib *calib)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	unsigned int tmp_msb, tmp_lsb;
+	int ret;
+
+	ret = regmap_bulk_read(data->regmap, BME680_T2_LSB_REG,
+			       data->bme680_cal_buf_1,
+			       sizeof(data->bme680_cal_buf_1));
+	if (ret < 0) {
+		dev_err(dev, "failed to read 1st set of calib data;\n");
+		return ret;
+	}
+
+	calib->par_t2 = get_unaligned_le16(&data->bme680_cal_buf_1[T2_LSB]);
+	calib->par_t3 = data->bme680_cal_buf_1[T3];
+	calib->par_p1 = get_unaligned_le16(&data->bme680_cal_buf_1[P1_LSB]);
+	calib->par_p2 = get_unaligned_le16(&data->bme680_cal_buf_1[P2_LSB]);
+	calib->par_p3 = data->bme680_cal_buf_1[P3];
+	calib->par_p4 = get_unaligned_le16(&data->bme680_cal_buf_1[P4_LSB]);
+	calib->par_p5 = get_unaligned_le16(&data->bme680_cal_buf_1[P5_LSB]);
+	calib->par_p7 = data->bme680_cal_buf_1[P7];
+	calib->par_p6 = data->bme680_cal_buf_1[P6];
+	calib->par_p8 = get_unaligned_le16(&data->bme680_cal_buf_1[P8_LSB]);
+	calib->par_p9 = get_unaligned_le16(&data->bme680_cal_buf_1[P9_LSB]);
+	calib->par_p10 = data->bme680_cal_buf_1[P10];
+
+	ret = regmap_bulk_read(data->regmap, BME680_H2_MSB_REG,
+			       data->bme680_cal_buf_2,
+			       sizeof(data->bme680_cal_buf_2));
+	if (ret < 0) {
+		dev_err(dev, "failed to read 2nd set of calib data;\n");
+		return ret;
+	}
+
+	tmp_lsb = data->bme680_cal_buf_2[H1_LSB];
+	tmp_msb = data->bme680_cal_buf_2[H1_LSB + 1];
+	calib->par_h1 = (tmp_msb << BME680_HUM_REG_SHIFT_VAL) |
+			(tmp_lsb & BME680_BIT_H1_DATA_MASK);
+
+	tmp_msb = data->bme680_cal_buf_2[H2_MSB];
+	tmp_lsb = data->bme680_cal_buf_2[H2_MSB + 1];
+	calib->par_h2 = (tmp_msb << BME680_HUM_REG_SHIFT_VAL) |
+			(tmp_lsb >> BME680_HUM_REG_SHIFT_VAL);
+
+	calib->par_h3 = data->bme680_cal_buf_2[H3];
+	calib->par_h4 = data->bme680_cal_buf_2[H4];
+	calib->par_h5 = data->bme680_cal_buf_2[H5];
+	calib->par_h6 = data->bme680_cal_buf_2[H6];
+	calib->par_h7 = data->bme680_cal_buf_2[H7];
+	calib->par_t1 = get_unaligned_le16(&data->bme680_cal_buf_2[T1_LSB]);
+	calib->par_gh2 = get_unaligned_le16(&data->bme680_cal_buf_2[GH2_LSB]);
+	calib->par_gh1 = data->bme680_cal_buf_2[GH1];
+	calib->par_gh3 = data->bme680_cal_buf_2[GH3];
+
+	ret = regmap_bulk_read(data->regmap, BME680_REG_RES_HEAT_VAL,
+			       data->bme680_cal_buf_3,
+			       sizeof(data->bme680_cal_buf_3));
+	if (ret < 0) {
+		dev_err(dev, "failed to read 3rd set of calib data;\n");
+		return ret;
+	}
+
+	calib->res_heat_val = data->bme680_cal_buf_3[RES_HEAT_VAL];
+
+	calib->res_heat_range = FIELD_GET(BME680_RHRANGE_MASK,
+					  data->bme680_cal_buf_3[RES_HEAT_RANGE]);
+
+	calib->range_sw_err = FIELD_GET(BME680_RSERROR_MASK,
+					data->bme680_cal_buf_3[RANGE_SW_ERR]);
+
+	return 0;
+}
+
+static int bme680_read_temp_adc(struct bme680_data *data, u32 *adc_temp)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	u32 value_temp;
+	int ret;
+
+	ret = regmap_bulk_read(data->regmap, BME680_REG_TEMP_MSB,
+			       data->buf, BME680_TEMP_NUM_BYTES);
+	if (ret < 0) {
+		dev_err(dev, "failed to read temperature\n");
+		return ret;
+	}
+
+	value_temp = FIELD_GET(BME680_MEAS_TRIM_MASK,
+			       get_unaligned_be24(data->buf));
+	if (value_temp == BME680_MEAS_SKIPPED) {
+		/* reading was skipped */
+		dev_err(dev, "reading temperature skipped\n");
+		return -EINVAL;
+	}
+	*adc_temp = value_temp;
+
+	return 0;
+}
+
+/*
+ * Taken from Bosch BME680 API:
+ * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L876
+ *
+ * Returns temperature measurement in DegC, resolutions is 0.01 DegC. Therefore,
+ * output value of "3233" represents 32.33 DegC.
+ */
+static s32 bme680_calc_t_fine(struct bme680_data *data, u32 adc_temp)
+{
+	struct bme680_calib *calib = &data->bme680;
+	s64 var1, var2, var3;
+
+	/* If the calibration is invalid, attempt to reload it */
+	if (!calib->par_t2)
+		bme680_read_calib(data, calib);
+
+	var1 = ((s32)adc_temp >> 3) - ((s32)calib->par_t1 << 1);
+	var2 = (var1 * calib->par_t2) >> 11;
+	var3 = ((var1 >> 1) * (var1 >> 1)) >> 12;
+	var3 = (var3 * ((s32)calib->par_t3 << 4)) >> 14;
+	return var2 + var3; /* t_fine = var2 + var3 */
+}
+
+static int bme680_get_t_fine(struct bme680_data *data, s32 *t_fine)
+{
+	u32 adc_temp;
+	int ret;
+
+	ret = bme680_read_temp_adc(data, &adc_temp);
+	if (ret)
+		return ret;
+
+	*t_fine = bme680_calc_t_fine(data, adc_temp);
+
+	return 0;
+}
+
+static s16 bme680_compensate_temp(struct bme680_data *data,
+				  u32 adc_temp)
+{
+	return (bme680_calc_t_fine(data, adc_temp) * 5 + 128) / 256;
+}
+
+static int bme680_read_press_adc(struct bme680_data *data, u32 *adc_press)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	u32 value_press;
+	int ret;
+
+	ret = regmap_bulk_read(data->regmap, BME680_REG_PRESS_MSB,
+			       data->buf, BME680_PRESS_NUM_BYTES);
+	if (ret < 0) {
+		dev_err(dev, "failed to read pressure\n");
+		return ret;
+	}
+
+	value_press = FIELD_GET(BME680_MEAS_TRIM_MASK,
+				get_unaligned_be24(data->buf));
+	if (value_press == BME680_MEAS_SKIPPED) {
+		/* reading was skipped */
+		dev_err(dev, "reading pressure skipped\n");
+		return -EINVAL;
+	}
+	*adc_press = value_press;
+
+	return 0;
+}
+
+/*
+ * Taken from Bosch BME680 API:
+ * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L896
+ *
+ * Returns pressure measurement in Pa. Output value of "97356" represents
+ * 97356 Pa = 973.56 hPa.
+ */
+static u32 bme680_compensate_press(struct bme680_data *data,
+				   u32 adc_press, s32 t_fine)
+{
+	struct bme680_calib *calib = &data->bme680;
+	s32 var1, var2, var3, press_comp;
+
+	var1 = (t_fine >> 1) - 64000;
+	var2 = ((((var1 >> 2) * (var1 >> 2)) >> 11) * calib->par_p6) >> 2;
+	var2 = var2 + (var1 * calib->par_p5 << 1);
+	var2 = (var2 >> 2) + ((s32)calib->par_p4 << 16);
+	var1 = (((((var1 >> 2) * (var1 >> 2)) >> 13) *
+			((s32)calib->par_p3 << 5)) >> 3) +
+			((calib->par_p2 * var1) >> 1);
+	var1 = var1 >> 18;
+	var1 = ((32768 + var1) * calib->par_p1) >> 15;
+	press_comp = 1048576 - adc_press;
+	press_comp = ((press_comp - (var2 >> 12)) * 3125);
+
+	if (press_comp >= BME680_MAX_OVERFLOW_VAL)
+		press_comp = ((press_comp / (u32)var1) << 1);
+	else
+		press_comp = ((press_comp << 1) / (u32)var1);
+
+	var1 = (calib->par_p9 * (((press_comp >> 3) *
+			(press_comp >> 3)) >> 13)) >> 12;
+	var2 = ((press_comp >> 2) * calib->par_p8) >> 13;
+	var3 = ((press_comp >> 8) * (press_comp >> 8) *
+			(press_comp >> 8) * calib->par_p10) >> 17;
+
+	press_comp += (var1 + var2 + var3 + ((s32)calib->par_p7 << 7)) >> 4;
+
+	return press_comp;
+}
+
+static int bme680_read_humid_adc(struct bme680_data *data, u32 *adc_humidity)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	u32 value_humidity;
+	int ret;
+
+	ret = regmap_bulk_read(data->regmap, BME680_REG_HUMIDITY_MSB,
+			       &data->be16, BME680_HUMID_NUM_BYTES);
+	if (ret < 0) {
+		dev_err(dev, "failed to read humidity\n");
+		return ret;
+	}
+
+	value_humidity = be16_to_cpu(data->be16);
+	if (value_humidity == BME680_MEAS_SKIPPED) {
+		/* reading was skipped */
+		dev_err(dev, "reading humidity skipped\n");
+		return -EINVAL;
+	}
+	*adc_humidity = value_humidity;
+
+	return 0;
+}
+
+/*
+ * Taken from Bosch BME680 API:
+ * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L937
+ *
+ * Returns humidity measurement in percent, resolution is 0.001 percent. Output
+ * value of "43215" represents 43.215 %rH.
+ */
+static u32 bme680_compensate_humid(struct bme680_data *data,
+				   u16 adc_humid, s32 t_fine)
+{
+	struct bme680_calib *calib = &data->bme680;
+	s32 var1, var2, var3, var4, var5, var6, temp_scaled, calc_hum;
+
+	temp_scaled = (t_fine * 5 + 128) >> 8;
+	var1 = (adc_humid - (((s32)calib->par_h1 * 16))) -
+		(((temp_scaled * calib->par_h3) / 100) >> 1);
+	var2 = (calib->par_h2 *
+		(((temp_scaled * calib->par_h4) / 100) +
+		 (((temp_scaled * ((temp_scaled * calib->par_h5) / 100))
+		   >> 6) / 100) + (1 << 14))) >> 10;
+	var3 = var1 * var2;
+	var4 = (s32)calib->par_h6 << 7;
+	var4 = (var4 + ((temp_scaled * calib->par_h7) / 100)) >> 4;
+	var5 = ((var3 >> 14) * (var3 >> 14)) >> 10;
+	var6 = (var4 * var5) >> 1;
+	calc_hum = (((var3 + var6) >> 10) * 1000) >> 12;
+
+	calc_hum = clamp(calc_hum, 0, 100000); /* clamp between 0-100 %rH */
+
+	return calc_hum;
+}
+
+/*
+ * Taken from Bosch BME680 API:
+ * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L973
+ *
+ * Returns gas measurement in Ohm. Output value of "82986" represent 82986 ohms.
+ */
+static u32 bme680_compensate_gas(struct bme680_data *data, u16 gas_res_adc,
+				 u8 gas_range)
+{
+	struct bme680_calib *calib = &data->bme680;
+	s64 var1;
+	u64 var2;
+	s64 var3;
+	u32 calc_gas_res;
+
+	/* Look up table for the possible gas range values */
+	static const u32 lookup_table[16] = {
+		2147483647u, 2147483647u, 2147483647u, 2147483647u,
+		2147483647u, 2126008810u, 2147483647u, 2130303777u,
+		2147483647u, 2147483647u, 2143188679u, 2136746228u,
+		2147483647u, 2126008810u, 2147483647u, 2147483647u
+	};
+
+	var1 = ((1340LL + (5 * calib->range_sw_err)) *
+			(lookup_table[gas_range])) >> 16;
+	var2 = ((gas_res_adc << 15) - 16777216) + var1;
+	var3 = ((125000 << (15 - gas_range)) * var1) >> 9;
+	var3 += (var2 >> 1);
+	calc_gas_res = div64_s64(var3, (s64)var2);
+
+	return calc_gas_res;
+}
+
+/*
+ * Taken from Bosch BME680 API:
+ * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L1002
+ */
+static u8 bme680_calc_heater_res(struct bme680_data *data, u16 temp)
+{
+	struct bme680_calib *calib = &data->bme680;
+	s32 var1, var2, var3, var4, var5, heatr_res_x100;
+	u8 heatr_res;
+
+	if (temp > 400) /* Cap temperature */
+		temp = 400;
+
+	var1 = (((s32)BME680_AMB_TEMP * calib->par_gh3) / 1000) * 256;
+	var2 = (calib->par_gh1 + 784) * (((((calib->par_gh2 + 154009) *
+						temp * 5) / 100)
+						+ 3276800) / 10);
+	var3 = var1 + (var2 / 2);
+	var4 = (var3 / (calib->res_heat_range + 4));
+	var5 = 131 * calib->res_heat_val + 65536;
+	heatr_res_x100 = ((var4 / var5) - 250) * 34;
+	heatr_res = DIV_ROUND_CLOSEST(heatr_res_x100, 100);
+
+	return heatr_res;
+}
+
+/*
+ * Taken from Bosch BME680 API:
+ * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L1188
+ */
+static u8 bme680_calc_heater_dur(u16 dur)
+{
+	u8 durval, factor = 0;
+
+	if (dur >= 0xfc0) {
+		durval = 0xff; /* Max duration */
+	} else {
+		while (dur > 0x3F) {
+			dur = dur / 4;
+			factor += 1;
+		}
+		durval = dur + (factor * 64);
+	}
+
+	return durval;
+}
+
+/* Taken from datasheet, section 5.3.3 */
+static u8 bme680_calc_heater_preheat_current(u8 curr)
+{
+	return 8 * curr - 1;
+}
+
+static int bme680_set_mode(struct bme680_data *data, enum bme680_op_mode mode)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+
+	ret = regmap_write_bits(data->regmap, BME680_REG_CTRL_MEAS,
+				BME680_MODE_MASK, mode);
+	if (ret < 0) {
+		dev_err(dev, "failed to set ctrl_meas register\n");
+		return ret;
+	}
+
+	return ret;
+}
+
+static u8 bme680_oversampling_to_reg(u8 val)
+{
+	return ilog2(val) + 1;
+}
+
+/*
+ * Taken from Bosch BME680 API:
+ * https://github.com/boschsensortec/BME68x_SensorAPI/blob/v4.4.8/bme68x.c#L490
+ */
+static int bme680_wait_for_eoc(struct bme680_data *data)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+	/*
+	 * (Sum of oversampling ratios * time per oversampling) +
+	 * TPH measurement + gas measurement + wait transition from forced mode
+	 * + heater duration
+	 */
+	int wait_eoc_us = ((data->oversampling_temp + data->oversampling_press +
+			   data->oversampling_humid) * 1963) + (477 * 4) +
+			   (477 * 5) + 1000 + (data->heater_dur * 1000);
+
+	fsleep(wait_eoc_us);
+
+	ret = regmap_read(data->regmap, BME680_REG_MEAS_STAT_0, &data->check);
+	if (ret) {
+		dev_err(dev, "failed to read measurement status register.\n");
+		return ret;
+	}
+	if (data->check & BME680_MEAS_BIT) {
+		dev_err(dev, "Device measurement cycle incomplete.\n");
+		return -EBUSY;
+	}
+	if (!(data->check & BME680_NEW_DATA_BIT)) {
+		dev_err(dev, "No new data available from the device.\n");
+		return -ENODATA;
+	}
+
+	return 0;
+}
+
+static int bme680_chip_config(struct bme680_data *data)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+	u8 osrs;
+
+	osrs = FIELD_PREP(BME680_OSRS_HUMIDITY_MASK,
+			  bme680_oversampling_to_reg(data->oversampling_humid));
+	/*
+	 * Highly recommended to set oversampling of humidity before
+	 * temperature/pressure oversampling.
+	 */
+	ret = regmap_update_bits(data->regmap, BME680_REG_CTRL_HUMIDITY,
+				 BME680_OSRS_HUMIDITY_MASK, osrs);
+	if (ret < 0) {
+		dev_err(dev, "failed to write ctrl_hum register\n");
+		return ret;
+	}
+
+	/* IIR filter settings */
+	ret = regmap_update_bits(data->regmap, BME680_REG_CONFIG,
+				 BME680_FILTER_MASK, BME680_FILTER_COEFF_VAL);
+	if (ret < 0) {
+		dev_err(dev, "failed to write config register\n");
+		return ret;
+	}
+
+	osrs = FIELD_PREP(BME680_OSRS_TEMP_MASK,
+			  bme680_oversampling_to_reg(data->oversampling_temp)) |
+	       FIELD_PREP(BME680_OSRS_PRESS_MASK,
+			  bme680_oversampling_to_reg(data->oversampling_press));
+	ret = regmap_write_bits(data->regmap, BME680_REG_CTRL_MEAS,
+				BME680_OSRS_TEMP_MASK | BME680_OSRS_PRESS_MASK,
+				osrs);
+	if (ret < 0) {
+		dev_err(dev, "failed to write ctrl_meas register\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int bme680_preheat_curr_config(struct bme680_data *data, u8 val)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	u8 heatr_curr;
+	int ret;
+
+	heatr_curr = bme680_calc_heater_preheat_current(val);
+	ret = regmap_write(data->regmap, BME680_REG_IDAC_HEAT_0, heatr_curr);
+	if (ret < 0)
+		dev_err(dev, "failed to write idac_heat_0 register\n");
+
+	return ret;
+}
+
+static int bme680_gas_config(struct bme680_data *data)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+	u8 heatr_res, heatr_dur;
+
+	ret = bme680_set_mode(data, BME680_MODE_SLEEP);
+	if (ret < 0)
+		return ret;
+
+	heatr_res = bme680_calc_heater_res(data, data->heater_temp);
+
+	/* set target heater temperature */
+	ret = regmap_write(data->regmap, BME680_REG_RES_HEAT_0, heatr_res);
+	if (ret < 0) {
+		dev_err(dev, "failed to write res_heat_0 register\n");
+		return ret;
+	}
+
+	heatr_dur = bme680_calc_heater_dur(data->heater_dur);
+
+	/* set target heating duration */
+	ret = regmap_write(data->regmap, BME680_REG_GAS_WAIT_0, heatr_dur);
+	if (ret < 0) {
+		dev_err(dev, "failed to write gas_wait_0 register\n");
+		return ret;
+	}
+
+	ret = bme680_preheat_curr_config(data, data->preheat_curr_mA);
+	if (ret)
+		return ret;
+
+	/* Enable the gas sensor and select heater profile set-point 0 */
+	ret = regmap_update_bits(data->regmap, BME680_REG_CTRL_GAS_1,
+				 BME680_RUN_GAS_MASK | BME680_NB_CONV_MASK,
+				 FIELD_PREP(BME680_RUN_GAS_MASK, 1) |
+				 FIELD_PREP(BME680_NB_CONV_MASK, 0));
+	if (ret < 0)
+		dev_err(dev, "failed to write ctrl_gas_1 register\n");
+
+	return ret;
+}
+
+static int bme680_read_temp(struct bme680_data *data, s16 *comp_temp)
+{
+	int ret;
+	u32 adc_temp;
+
+	ret = bme680_read_temp_adc(data, &adc_temp);
+	if (ret)
+		return ret;
+
+	*comp_temp = bme680_compensate_temp(data, adc_temp);
+	return 0;
+}
+
+static int bme680_read_press(struct bme680_data *data, u32 *comp_press)
+{
+	int ret;
+	u32 adc_press;
+	s32 t_fine;
+
+	ret = bme680_get_t_fine(data, &t_fine);
+	if (ret)
+		return ret;
+
+	ret = bme680_read_press_adc(data, &adc_press);
+	if (ret)
+		return ret;
+
+	*comp_press = bme680_compensate_press(data, adc_press, t_fine);
+	return 0;
+}
+
+static int bme680_read_humid(struct bme680_data *data, u32 *comp_humidity)
+{
+	int ret;
+	u32 adc_humidity;
+	s32 t_fine;
+
+	ret = bme680_get_t_fine(data, &t_fine);
+	if (ret)
+		return ret;
+
+	ret = bme680_read_humid_adc(data, &adc_humidity);
+	if (ret)
+		return ret;
+
+	*comp_humidity = bme680_compensate_humid(data, adc_humidity, t_fine);
+	return 0;
+}
+
+static int bme680_read_gas(struct bme680_data *data, int *comp_gas_res)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+	u16 adc_gas_res, gas_regs_val;
+	u8 gas_range;
+
+	ret = regmap_read(data->regmap, BME680_REG_MEAS_STAT_0, &data->check);
+	if (data->check & BME680_GAS_MEAS_BIT) {
+		dev_err(dev, "gas measurement incomplete\n");
+		return -EBUSY;
+	}
+
+	ret = regmap_bulk_read(data->regmap, BME680_REG_GAS_MSB,
+			       &data->be16, BME680_GAS_NUM_BYTES);
+	if (ret < 0) {
+		dev_err(dev, "failed to read gas resistance\n");
+		return ret;
+	}
+
+	gas_regs_val = be16_to_cpu(data->be16);
+	adc_gas_res = FIELD_GET(BME680_ADC_GAS_RES, gas_regs_val);
+
+	/*
+	 * This may occur if either the gas heating duration was insufficient
+	 * to reach the target heater temperature or the target
+	 * heater temperature was too high for the heater sink to
+	 * reach.
+	 */
+	if ((gas_regs_val & BME680_GAS_STAB_BIT) == 0) {
+		dev_err(dev, "heater failed to reach the target temperature\n");
+		return -EINVAL;
+	}
+
+	gas_range = FIELD_GET(BME680_GAS_RANGE_MASK, gas_regs_val);
+	*comp_gas_res = bme680_compensate_gas(data, adc_gas_res, gas_range);
+	return 0;
+}
+
+static int __bme680_read_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int *val, int *val2, long mask)
+{
+	struct bme680_data *data = iio_priv(indio_dev);
+	int chan_val, ret;
+	s16 temp_chan_val;
+
+	guard(mutex)(&data->lock);
+
+	ret = bme680_set_mode(data, BME680_MODE_FORCED);
+	if (ret < 0)
+		return ret;
+
+	ret = bme680_wait_for_eoc(data);
+	if (ret)
+		return ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_PROCESSED:
+		switch (chan->type) {
+		case IIO_TEMP:
+			ret = bme680_read_temp(data, &temp_chan_val);
+			if (ret)
+				return ret;
+
+			*val = temp_chan_val * 10;
+			return IIO_VAL_INT;
+		case IIO_PRESSURE:
+			ret = bme680_read_press(data, &chan_val);
+			if (ret)
+				return ret;
+
+			*val = chan_val;
+			*val2 = 1000;
+			return IIO_VAL_FRACTIONAL;
+		case IIO_HUMIDITYRELATIVE:
+			ret = bme680_read_humid(data, &chan_val);
+			if (ret)
+				return ret;
+
+			*val = chan_val;
+			*val2 = 1000;
+			return IIO_VAL_FRACTIONAL;
+		case IIO_RESISTANCE:
+			ret = bme680_read_gas(data, &chan_val);
+			if (ret)
+				return ret;
+
+			*val = chan_val;
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_RAW:
+		switch (chan->type) {
+		case IIO_TEMP:
+			ret = bme680_read_temp(data, &temp_chan_val);
+			if (ret)
+				return ret;
+
+			*val = temp_chan_val;
+			return IIO_VAL_INT;
+		case IIO_PRESSURE:
+			ret = bme680_read_press(data, &chan_val);
+			if (ret)
+				return ret;
+
+			*val = chan_val;
+			return IIO_VAL_INT;
+		case IIO_HUMIDITYRELATIVE:
+			ret = bme680_read_humid(data, &chan_val);
+			if (ret)
+				return ret;
+
+			*val = chan_val;
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_TEMP:
+			*val = 10;
+			return IIO_VAL_INT;
+		case IIO_PRESSURE:
+			*val = 1;
+			*val2 = 1000;
+			return IIO_VAL_FRACTIONAL;
+		case IIO_HUMIDITYRELATIVE:
+			*val = 1;
+			*val2 = 1000;
+			return IIO_VAL_FRACTIONAL;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		switch (chan->type) {
+		case IIO_TEMP:
+			*val = data->oversampling_temp;
+			return IIO_VAL_INT;
+		case IIO_PRESSURE:
+			*val = data->oversampling_press;
+			return IIO_VAL_INT;
+		case IIO_HUMIDITYRELATIVE:
+			*val = data->oversampling_humid;
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+}
+
+static int bme680_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val, int *val2, long mask)
+{
+	struct bme680_data *data = iio_priv(indio_dev);
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+
+	ret = pm_runtime_resume_and_get(dev);
+	if (ret)
+		return ret;
+
+	ret = __bme680_read_raw(indio_dev, chan, val, val2, mask);
+	pm_runtime_put_autosuspend(dev);
+
+	return ret;
+}
+
+static bool bme680_is_valid_oversampling(int rate)
+{
+	return (rate > 0 && rate <= 16 && is_power_of_2(rate));
+}
+
+static int __bme680_write_raw(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan,
+			      int val, int val2, long mask)
+{
+	struct bme680_data *data = iio_priv(indio_dev);
+
+	guard(mutex)(&data->lock);
+
+	if (val2 != 0)
+		return -EINVAL;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+	{
+		if (!bme680_is_valid_oversampling(val))
+			return -EINVAL;
+
+		switch (chan->type) {
+		case IIO_TEMP:
+			data->oversampling_temp = val;
+			break;
+		case IIO_PRESSURE:
+			data->oversampling_press = val;
+			break;
+		case IIO_HUMIDITYRELATIVE:
+			data->oversampling_humid = val;
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		return bme680_chip_config(data);
+	}
+	case IIO_CHAN_INFO_PROCESSED:
+	{
+		switch (chan->type) {
+		case IIO_CURRENT:
+			return bme680_preheat_curr_config(data, (u8)val);
+		default:
+			return -EINVAL;
+		}
+	}
+	default:
+		return -EINVAL;
+	}
+}
+
+static int bme680_write_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int val, int val2, long mask)
+{
+	struct bme680_data *data = iio_priv(indio_dev);
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+
+	ret = pm_runtime_resume_and_get(dev);
+	if (ret)
+		return ret;
+
+	ret = __bme680_write_raw(indio_dev, chan, val, val2, mask);
+	pm_runtime_put_autosuspend(dev);
+
+	return ret;
+}
+
+static const char bme680_oversampling_ratio_show[] = "1 2 4 8 16";
+
+static IIO_CONST_ATTR(oversampling_ratio_available,
+		      bme680_oversampling_ratio_show);
+
+static struct attribute *bme680_attributes[] = {
+	&iio_const_attr_oversampling_ratio_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group bme680_attribute_group = {
+	.attrs = bme680_attributes,
+};
+
+static const struct iio_info bme680_info = {
+	.read_raw = &bme680_read_raw,
+	.write_raw = &bme680_write_raw,
+	.attrs = &bme680_attribute_group,
+};
+
+static const unsigned long bme680_avail_scan_masks[] = {
+	BIT(BME680_GAS) | BIT(BME680_HUMID) | BIT(BME680_PRESS) | BIT(BME680_TEMP),
+	0
+};
+
+static irqreturn_t bme680_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct bme680_data *data = iio_priv(indio_dev);
+	struct device *dev = regmap_get_device(data->regmap);
+	u32 adc_temp, adc_press, adc_humid;
+	u16 adc_gas_res, gas_regs_val;
+	u8 gas_range;
+	s32 t_fine;
+	int ret;
+
+	guard(mutex)(&data->lock);
+
+	ret = bme680_set_mode(data, BME680_MODE_FORCED);
+	if (ret < 0)
+		goto out;
+
+	ret = bme680_wait_for_eoc(data);
+	if (ret)
+		goto out;
+
+	ret = regmap_bulk_read(data->regmap, BME680_REG_MEAS_STAT_0,
+			       data->buf, sizeof(data->buf));
+	if (ret) {
+		dev_err(dev, "failed to burst read sensor data\n");
+		goto out;
+	}
+	if (data->buf[0] & BME680_GAS_MEAS_BIT) {
+		dev_err(dev, "gas measurement incomplete\n");
+		goto out;
+	}
+
+	/* Temperature calculations */
+	adc_temp = FIELD_GET(BME680_MEAS_TRIM_MASK, get_unaligned_be24(&data->buf[5]));
+	if (adc_temp == BME680_MEAS_SKIPPED) {
+		dev_err(dev, "reading temperature skipped\n");
+		goto out;
+	}
+	data->scan.chan[0] = bme680_compensate_temp(data, adc_temp);
+	t_fine = bme680_calc_t_fine(data, adc_temp);
+
+	/* Pressure calculations */
+	adc_press = FIELD_GET(BME680_MEAS_TRIM_MASK, get_unaligned_be24(&data->buf[2]));
+	if (adc_press == BME680_MEAS_SKIPPED) {
+		dev_err(dev, "reading pressure skipped\n");
+		goto out;
+	}
+	data->scan.chan[1] = bme680_compensate_press(data, adc_press, t_fine);
+
+	/* Humidity calculations */
+	adc_humid = get_unaligned_be16(&data->buf[8]);
+	if (adc_humid == BME680_MEAS_SKIPPED) {
+		dev_err(dev, "reading humidity skipped\n");
+		goto out;
+	}
+	data->scan.chan[2] = bme680_compensate_humid(data, adc_humid, t_fine);
+
+	/* Gas calculations */
+	gas_regs_val = get_unaligned_be16(&data->buf[13]);
+	adc_gas_res = FIELD_GET(BME680_ADC_GAS_RES, gas_regs_val);
+	if ((gas_regs_val & BME680_GAS_STAB_BIT) == 0) {
+		dev_err(dev, "heater failed to reach the target temperature\n");
+		goto out;
+	}
+	gas_range = FIELD_GET(BME680_GAS_RANGE_MASK, gas_regs_val);
+	data->scan.chan[3] = bme680_compensate_gas(data, adc_gas_res, gas_range);
+
+	iio_push_to_buffers_with_ts(indio_dev, &data->scan, sizeof(data->scan),
+				    iio_get_time_ns(indio_dev));
+out:
+	iio_trigger_notify_done(indio_dev->trig);
+	return IRQ_HANDLED;
+}
+
+static int bme680_buffer_preenable(struct iio_dev *indio_dev)
+{
+	struct bme680_data *data = iio_priv(indio_dev);
+	struct device *dev = regmap_get_device(data->regmap);
+
+	return pm_runtime_resume_and_get(dev);
+}
+
+static int bme680_buffer_postdisable(struct iio_dev *indio_dev)
+{
+	struct bme680_data *data = iio_priv(indio_dev);
+	struct device *dev = regmap_get_device(data->regmap);
+
+	pm_runtime_put_autosuspend(dev);
+	return 0;
+}
+
+static const struct iio_buffer_setup_ops bme680_buffer_setup_ops = {
+	.preenable = bme680_buffer_preenable,
+	.postdisable = bme680_buffer_postdisable,
+};
+
+int bme680_core_probe(struct device *dev, struct regmap *regmap,
+		      const char *name)
+{
+	struct iio_dev *indio_dev;
+	struct bme680_data *data;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	mutex_init(&data->lock);
+	dev_set_drvdata(dev, indio_dev);
+	data->regmap = regmap;
+	indio_dev->name = name;
+	indio_dev->channels = bme680_channels;
+	indio_dev->num_channels = ARRAY_SIZE(bme680_channels);
+	indio_dev->available_scan_masks = bme680_avail_scan_masks;
+	indio_dev->info = &bme680_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	/* default values for the sensor */
+	data->oversampling_humid = 2; /* 2X oversampling rate */
+	data->oversampling_press = 4; /* 4X oversampling rate */
+	data->oversampling_temp = 8;  /* 8X oversampling rate */
+	data->heater_temp = 320; /* degree Celsius */
+	data->heater_dur = 150;  /* milliseconds */
+	data->preheat_curr_mA = 0;
+
+	ret = devm_regulator_bulk_get_enable(dev, ARRAY_SIZE(bme680_supply_names),
+					     bme680_supply_names);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "failed to get and enable supplies.\n");
+
+	fsleep(BME680_STARTUP_TIME_US);
+
+	ret = regmap_write(regmap, BME680_REG_SOFT_RESET, BME680_CMD_SOFTRESET);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Failed to reset chip\n");
+
+	fsleep(BME680_STARTUP_TIME_US);
+
+	ret = regmap_read(regmap, BME680_REG_CHIP_ID, &data->check);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Error reading chip ID\n");
+
+	if (data->check != BME680_CHIP_ID_VAL) {
+		dev_err(dev, "Wrong chip ID, got %x expected %x\n",
+			data->check, BME680_CHIP_ID_VAL);
+		return -ENODEV;
+	}
+
+	ret = bme680_read_calib(data, &data->bme680);
+	if (ret < 0) {
+		return dev_err_probe(dev, ret,
+			"failed to read calibration coefficients at probe\n");
+	}
+
+	ret = bme680_chip_config(data);
+	if (ret < 0)
+		return dev_err_probe(dev, ret,
+				     "failed to set chip_config data\n");
+
+	ret = bme680_gas_config(data);
+	if (ret < 0)
+		return dev_err_probe(dev, ret,
+				     "failed to set gas config data\n");
+
+	ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
+					      iio_pollfunc_store_time,
+					      bme680_trigger_handler,
+					      &bme680_buffer_setup_ops);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "iio triggered buffer setup failed\n");
+
+	/* Enable runtime PM */
+	pm_runtime_set_autosuspend_delay(dev, BME680_STARTUP_TIME_US);
+	pm_runtime_use_autosuspend(dev);
+	pm_runtime_set_active(dev);
+	ret = devm_pm_runtime_enable(dev);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+EXPORT_SYMBOL_NS_GPL(bme680_core_probe, "IIO_BME680");
+
+static int bme680_runtime_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct bme680_data *data = iio_priv(indio_dev);
+
+	return bme680_set_mode(data, BME680_MODE_SLEEP);
+}
+
+static int bme680_runtime_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct bme680_data *data = iio_priv(indio_dev);
+	int ret;
+
+	ret = bme680_chip_config(data);
+	if (ret)
+		return ret;
+
+	return bme680_gas_config(data);
+}
+
+EXPORT_RUNTIME_DEV_PM_OPS(bme680_dev_pm_ops, bme680_runtime_suspend,
+			  bme680_runtime_resume, NULL);
+
+MODULE_AUTHOR("Himanshu Jha <himanshujha199640@gmail.com>");
+MODULE_DESCRIPTION("Bosch BME680 Driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/chemical/bme680_i2c.c b/drivers/iio/chemical/bme680_i2c.c
new file mode 100644
index 000000000..c34d67bcb
--- /dev/null
+++ b/drivers/iio/chemical/bme680_i2c.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * BME680 - I2C Driver
+ *
+ * Copyright (C) 2018 Himanshu Jha <himanshujha199640@gmail.com>
+ *
+ * 7-Bit I2C slave address is:
+ *	- 0x76 if SDO is pulled to GND
+ *	- 0x77 if SDO is pulled to VDDIO
+ *
+ * Note: SDO pin cannot be left floating otherwise I2C address
+ *	 will be undefined.
+ */
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include "bme680.h"
+
+static int bme680_i2c_probe(struct i2c_client *client)
+{
+	const struct i2c_device_id *id = i2c_client_get_device_id(client);
+	struct regmap *regmap;
+	const char *name = NULL;
+
+	regmap = devm_regmap_init_i2c(client, &bme680_regmap_config);
+	if (IS_ERR(regmap))
+		return dev_err_probe(&client->dev, PTR_ERR(regmap),
+				     "Failed to register i2c regmap\n");
+
+	if (id)
+		name = id->name;
+
+	return bme680_core_probe(&client->dev, regmap, name);
+}
+
+static const struct i2c_device_id bme680_i2c_id[] = {
+	{ .name = "bme680" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, bme680_i2c_id);
+
+static const struct of_device_id bme680_of_i2c_match[] = {
+	{ .compatible = "bosch,bme680", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, bme680_of_i2c_match);
+
+static struct i2c_driver bme680_i2c_driver = {
+	.driver = {
+		.name			= "bme680_i2c",
+		.of_match_table		= bme680_of_i2c_match,
+		.pm = pm_ptr(&bme680_dev_pm_ops),
+	},
+	.probe = bme680_i2c_probe,
+	.id_table = bme680_i2c_id,
+};
+module_i2c_driver(bme680_i2c_driver);
+
+MODULE_AUTHOR("Himanshu Jha <himanshujha199640@gmail.com>");
+MODULE_DESCRIPTION("BME680 I2C driver");
+MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS("IIO_BME680");
diff --git a/drivers/iio/chemical/bme680_spi.c b/drivers/iio/chemical/bme680_spi.c
new file mode 100644
index 000000000..2175b9564
--- /dev/null
+++ b/drivers/iio/chemical/bme680_spi.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * BME680 - SPI Driver
+ *
+ * Copyright (C) 2018 Himanshu Jha <himanshujha199640@gmail.com>
+ */
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+
+#include "bme680.h"
+
+struct bme680_spi_bus_context {
+	struct spi_device *spi;
+	u8 current_page;
+};
+
+/*
+ * In SPI mode there are only 7 address bits, a "page" register determines
+ * which part of the 8-bit range is active. This function looks at the address
+ * and writes the page selection bit if needed
+ */
+static int bme680_regmap_spi_select_page(
+	struct bme680_spi_bus_context *ctx, u8 reg)
+{
+	struct spi_device *spi = ctx->spi;
+	int ret;
+	u8 buf[2];
+	u8 page = (reg & 0x80) ? 0 : 1; /* Page "1" is low range */
+
+	if (page == ctx->current_page)
+		return 0;
+
+	/*
+	 * Data sheet claims we're only allowed to change bit 4, so we must do
+	 * a read-modify-write on each and every page select
+	 */
+	buf[0] = BME680_REG_STATUS;
+	ret = spi_write_then_read(spi, buf, 1, buf + 1, 1);
+	if (ret < 0) {
+		dev_err(&spi->dev, "failed to set page %u\n", page);
+		return ret;
+	}
+
+	buf[0] = BME680_REG_STATUS;
+	if (page)
+		buf[1] |= BME680_SPI_MEM_PAGE_BIT;
+	else
+		buf[1] &= ~BME680_SPI_MEM_PAGE_BIT;
+
+	ret = spi_write(spi, buf, 2);
+	if (ret < 0) {
+		dev_err(&spi->dev, "failed to set page %u\n", page);
+		return ret;
+	}
+
+	ctx->current_page = page;
+
+	return 0;
+}
+
+static int bme680_regmap_spi_write(void *context, const void *data,
+				   size_t count)
+{
+	struct bme680_spi_bus_context *ctx = context;
+	struct spi_device *spi = ctx->spi;
+	int ret;
+	u8 buf[2];
+
+	memcpy(buf, data, 2);
+
+	ret = bme680_regmap_spi_select_page(ctx, buf[0]);
+	if (ret)
+		return ret;
+
+	/*
+	 * The SPI register address (= full register address without bit 7)
+	 * and the write command (bit7 = RW = '0')
+	 */
+	buf[0] &= ~0x80;
+
+	return spi_write(spi, buf, 2);
+}
+
+static int bme680_regmap_spi_read(void *context, const void *reg,
+				  size_t reg_size, void *val, size_t val_size)
+{
+	struct bme680_spi_bus_context *ctx = context;
+	struct spi_device *spi = ctx->spi;
+	int ret;
+	u8 addr = *(const u8 *)reg;
+
+	ret = bme680_regmap_spi_select_page(ctx, addr);
+	if (ret)
+		return ret;
+
+	addr |= 0x80; /* bit7 = RW = '1' */
+
+	return spi_write_then_read(spi, &addr, 1, val, val_size);
+}
+
+static const struct regmap_bus bme680_regmap_bus = {
+	.write = bme680_regmap_spi_write,
+	.read = bme680_regmap_spi_read,
+	.reg_format_endian_default = REGMAP_ENDIAN_BIG,
+	.val_format_endian_default = REGMAP_ENDIAN_BIG,
+};
+
+static int bme680_spi_probe(struct spi_device *spi)
+{
+	const struct spi_device_id *id = spi_get_device_id(spi);
+	struct bme680_spi_bus_context *bus_context;
+	struct regmap *regmap;
+
+	bus_context = devm_kzalloc(&spi->dev, sizeof(*bus_context), GFP_KERNEL);
+	if (!bus_context)
+		return -ENOMEM;
+
+	bus_context->spi = spi;
+	bus_context->current_page = 0xff; /* Undefined on warm boot */
+
+	regmap = devm_regmap_init(&spi->dev, &bme680_regmap_bus,
+				  bus_context, &bme680_regmap_config);
+	if (IS_ERR(regmap))
+		return dev_err_probe(&spi->dev, PTR_ERR(regmap),
+				     "Failed to register spi regmap\n");
+
+	return bme680_core_probe(&spi->dev, regmap, id->name);
+}
+
+static const struct spi_device_id bme680_spi_id[] = {
+	{ .name = "bme680" },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, bme680_spi_id);
+
+static const struct of_device_id bme680_of_spi_match[] = {
+	{ .compatible = "bosch,bme680", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, bme680_of_spi_match);
+
+static struct spi_driver bme680_spi_driver = {
+	.driver = {
+		.name			= "bme680_spi",
+		.of_match_table		= bme680_of_spi_match,
+		.pm = pm_ptr(&bme680_dev_pm_ops),
+	},
+	.probe = bme680_spi_probe,
+	.id_table = bme680_spi_id,
+};
+module_spi_driver(bme680_spi_driver);
+
+MODULE_AUTHOR("Himanshu Jha <himanshujha199640@gmail.com>");
+MODULE_DESCRIPTION("Bosch BME680 SPI driver");
+MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS("IIO_BME680");
diff --git a/drivers/iio/chemical/ccs811.c b/drivers/iio/chemical/ccs811.c
new file mode 100644
index 000000000..d126ee12f
--- /dev/null
+++ b/drivers/iio/chemical/ccs811.c
@@ -0,0 +1,577 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ccs811.c - Support for AMS CCS811 VOC Sensor
+ *
+ * Copyright (C) 2017 Narcisa Vasile <narcisaanamaria12@gmail.com>
+ *
+ * Datasheet: ams.com/content/download/951091/2269479/CCS811_DS000459_3-00.pdf
+ *
+ * IIO driver for AMS CCS811 (I2C address 0x5A/0x5B set by ADDR Low/High)
+ *
+ * TODO:
+ * 1. Make the drive mode selectable form userspace
+ * 2. Add support for interrupts
+ * 3. Adjust time to wait for data to be ready based on selected operation mode
+ * 4. Read error register and put the information in logs
+ */
+
+#include <linux/cleanup.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/module.h>
+
+#define CCS811_STATUS		0x00
+#define CCS811_MEAS_MODE	0x01
+#define CCS811_ALG_RESULT_DATA	0x02
+#define CCS811_RAW_DATA		0x03
+#define CCS811_HW_ID		0x20
+#define CCS811_HW_ID_VALUE	0x81
+#define CCS811_HW_VERSION	0x21
+#define CCS811_HW_VERSION_VALUE	0x10
+#define CCS811_HW_VERSION_MASK	0xF0
+#define CCS811_ERR		0xE0
+/* Used to transition from boot to application mode */
+#define CCS811_APP_START	0xF4
+#define CCS811_SW_RESET		0xFF
+
+/* Status register flags */
+#define CCS811_STATUS_ERROR		BIT(0)
+#define CCS811_STATUS_DATA_READY	BIT(3)
+#define CCS811_STATUS_APP_VALID_MASK	BIT(4)
+#define CCS811_STATUS_APP_VALID_LOADED	BIT(4)
+/*
+ * Value of FW_MODE bit of STATUS register describes the sensor's state:
+ * 0: Firmware is in boot mode, this allows new firmware to be loaded
+ * 1: Firmware is in application mode. CCS811 is ready to take ADC measurements
+ */
+#define CCS811_STATUS_FW_MODE_MASK	BIT(7)
+#define CCS811_STATUS_FW_MODE_APPLICATION	BIT(7)
+
+/* Measurement modes */
+#define CCS811_MODE_IDLE	0x00
+#define CCS811_MODE_IAQ_1SEC	0x10
+#define CCS811_MODE_IAQ_10SEC	0x20
+#define CCS811_MODE_IAQ_60SEC	0x30
+#define CCS811_MODE_RAW_DATA	0x40
+
+#define CCS811_MEAS_MODE_INTERRUPT	BIT(3)
+
+#define CCS811_VOLTAGE_MASK	0x3FF
+
+struct ccs811_reading {
+	__be16 co2;
+	__be16 voc;
+	u8 status;
+	u8 error;
+	__be16 raw_data;
+} __attribute__((__packed__));
+
+struct ccs811_data {
+	struct i2c_client *client;
+	struct mutex lock; /* Protect readings */
+	struct ccs811_reading buffer;
+	struct iio_trigger *drdy_trig;
+	struct gpio_desc *wakeup_gpio;
+	bool drdy_trig_on;
+	/* Ensures correct alignment of timestamp if present */
+	struct {
+		s16 channels[2];
+		aligned_s64 ts;
+	} scan;
+};
+
+static const struct iio_chan_spec ccs811_channels[] = {
+	{
+		.type = IIO_CURRENT,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE),
+		.scan_index = -1,
+	}, {
+		.type = IIO_VOLTAGE,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE),
+		.scan_index = -1,
+	}, {
+		.type = IIO_CONCENTRATION,
+		.channel2 = IIO_MOD_CO2,
+		.modified = 1,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE),
+		.scan_index = 0,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_BE,
+		},
+	}, {
+		.type = IIO_CONCENTRATION,
+		.channel2 = IIO_MOD_VOC,
+		.modified = 1,
+		.info_mask_separate =  BIT(IIO_CHAN_INFO_RAW) |
+				       BIT(IIO_CHAN_INFO_SCALE),
+		.scan_index = 1,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_BE,
+		},
+	},
+	IIO_CHAN_SOFT_TIMESTAMP(2),
+};
+
+/*
+ * The CCS811 powers-up in boot mode. A setup write to CCS811_APP_START will
+ * transition the sensor to application mode.
+ */
+static int ccs811_start_sensor_application(struct i2c_client *client)
+{
+	int ret;
+
+	ret = i2c_smbus_read_byte_data(client, CCS811_STATUS);
+	if (ret < 0)
+		return ret;
+
+	if ((ret & CCS811_STATUS_FW_MODE_APPLICATION))
+		return 0;
+
+	if ((ret & CCS811_STATUS_APP_VALID_MASK) !=
+	    CCS811_STATUS_APP_VALID_LOADED)
+		return -EIO;
+
+	ret = i2c_smbus_write_byte(client, CCS811_APP_START);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_read_byte_data(client, CCS811_STATUS);
+	if (ret < 0)
+		return ret;
+
+	if ((ret & CCS811_STATUS_FW_MODE_MASK) !=
+	    CCS811_STATUS_FW_MODE_APPLICATION) {
+		dev_err(&client->dev, "Application failed to start. Sensor is still in boot mode.\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int ccs811_setup(struct i2c_client *client)
+{
+	int ret;
+
+	ret = ccs811_start_sensor_application(client);
+	if (ret < 0)
+		return ret;
+
+	return i2c_smbus_write_byte_data(client, CCS811_MEAS_MODE,
+					 CCS811_MODE_IAQ_1SEC);
+}
+
+static void ccs811_set_wakeup(struct ccs811_data *data, bool enable)
+{
+	if (!data->wakeup_gpio)
+		return;
+
+	gpiod_set_value(data->wakeup_gpio, enable);
+
+	if (enable)
+		usleep_range(50, 60);
+	else
+		usleep_range(20, 30);
+}
+
+static int ccs811_get_measurement(struct ccs811_data *data)
+{
+	int ret, tries = 11;
+
+	ccs811_set_wakeup(data, true);
+
+	/* Maximum waiting time: 1s, as measurements are made every second */
+	while (tries-- > 0) {
+		ret = i2c_smbus_read_byte_data(data->client, CCS811_STATUS);
+		if (ret < 0)
+			return ret;
+
+		if ((ret & CCS811_STATUS_DATA_READY) || tries == 0)
+			break;
+		msleep(100);
+	}
+	if (!(ret & CCS811_STATUS_DATA_READY))
+		return -EIO;
+
+	ret = i2c_smbus_read_i2c_block_data(data->client,
+					    CCS811_ALG_RESULT_DATA, 8,
+					    (char *)&data->buffer);
+	ccs811_set_wakeup(data, false);
+
+	return ret;
+}
+
+static int ccs811_read_info_raw(struct ccs811_data *data,
+				struct iio_chan_spec const *chan,
+				int *val, int mask)
+{
+	int ret;
+
+	guard(mutex)(&data->lock);
+	ret = ccs811_get_measurement(data);
+	if (ret < 0)
+		return ret;
+
+	switch (chan->type) {
+	case IIO_VOLTAGE:
+		*val = be16_to_cpu(data->buffer.raw_data) & CCS811_VOLTAGE_MASK;
+		return IIO_VAL_INT;
+	case IIO_CURRENT:
+		*val = be16_to_cpu(data->buffer.raw_data) >> 10;
+		return IIO_VAL_INT;
+	case IIO_CONCENTRATION:
+		switch (chan->channel2) {
+		case IIO_MOD_CO2:
+			*val = be16_to_cpu(data->buffer.co2);
+			return IIO_VAL_INT;
+		case IIO_MOD_VOC:
+			*val = be16_to_cpu(data->buffer.voc);
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ccs811_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val, int *val2, long mask)
+{
+	struct ccs811_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		if (!iio_device_claim_direct(indio_dev))
+			return -EBUSY;
+
+		ret = ccs811_read_info_raw(data, chan, val, mask);
+
+		iio_device_release_direct(indio_dev);
+
+		return ret;
+
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_VOLTAGE:
+			*val = 1;
+			*val2 = 612903;
+			return IIO_VAL_INT_PLUS_MICRO;
+		case IIO_CURRENT:
+			*val = 0;
+			*val2 = 1000;
+			return IIO_VAL_INT_PLUS_MICRO;
+		case IIO_CONCENTRATION:
+			switch (chan->channel2) {
+			case IIO_MOD_CO2:
+				*val = 0;
+				*val2 = 100;
+				return IIO_VAL_INT_PLUS_MICRO;
+			case IIO_MOD_VOC:
+				*val = 0;
+				*val2 = 100;
+				return IIO_VAL_INT_PLUS_NANO;
+			default:
+				return -EINVAL;
+			}
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info ccs811_info = {
+	.read_raw = ccs811_read_raw,
+};
+
+static int ccs811_set_trigger_state(struct iio_trigger *trig,
+				    bool state)
+{
+	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+	struct ccs811_data *data = iio_priv(indio_dev);
+	int ret;
+
+	ret = i2c_smbus_read_byte_data(data->client, CCS811_MEAS_MODE);
+	if (ret < 0)
+		return ret;
+
+	if (state)
+		ret |= CCS811_MEAS_MODE_INTERRUPT;
+	else
+		ret &= ~CCS811_MEAS_MODE_INTERRUPT;
+
+	data->drdy_trig_on = state;
+
+	return i2c_smbus_write_byte_data(data->client, CCS811_MEAS_MODE, ret);
+}
+
+static const struct iio_trigger_ops ccs811_trigger_ops = {
+	.set_trigger_state = ccs811_set_trigger_state,
+};
+
+static irqreturn_t ccs811_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct ccs811_data *data = iio_priv(indio_dev);
+	struct i2c_client *client = data->client;
+	int ret;
+
+	ret = i2c_smbus_read_i2c_block_data(client, CCS811_ALG_RESULT_DATA,
+					    sizeof(data->scan.channels),
+					    (u8 *)data->scan.channels);
+	if (ret != 4) {
+		dev_err(&client->dev, "cannot read sensor data\n");
+		goto err;
+	}
+
+	iio_push_to_buffers_with_ts(indio_dev, &data->scan, sizeof(data->scan),
+				    iio_get_time_ns(indio_dev));
+
+err:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t ccs811_data_rdy_trigger_poll(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct ccs811_data *data = iio_priv(indio_dev);
+
+	if (data->drdy_trig_on)
+		iio_trigger_poll(data->drdy_trig);
+
+	return IRQ_HANDLED;
+}
+
+static int ccs811_reset(struct i2c_client *client)
+{
+	struct gpio_desc *reset_gpio;
+	int ret;
+
+	reset_gpio = devm_gpiod_get_optional(&client->dev, "reset",
+					     GPIOD_OUT_LOW);
+	if (IS_ERR(reset_gpio))
+		return PTR_ERR(reset_gpio);
+
+	/* Try to reset using nRESET pin if available else do SW reset */
+	if (reset_gpio) {
+		gpiod_set_value(reset_gpio, 1);
+		usleep_range(20, 30);
+		gpiod_set_value(reset_gpio, 0);
+	} else {
+		/*
+		 * As per the datasheet, this sequence of values needs to be
+		 * written to the SW_RESET register for triggering the soft
+		 * reset in the device and placing it in boot mode.
+		 */
+		static const u8 reset_seq[] = {
+			0x11, 0xE5, 0x72, 0x8A,
+		};
+
+		ret = i2c_smbus_write_i2c_block_data(client, CCS811_SW_RESET,
+					     sizeof(reset_seq), reset_seq);
+		if (ret < 0) {
+			dev_err(&client->dev, "Failed to reset sensor\n");
+			return ret;
+		}
+	}
+
+	/* tSTART delay required after reset */
+	usleep_range(1000, 2000);
+
+	return 0;
+}
+
+static int ccs811_probe(struct i2c_client *client)
+{
+	const struct i2c_device_id *id = i2c_client_get_device_id(client);
+	struct iio_dev *indio_dev;
+	struct ccs811_data *data;
+	int ret;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE
+				     | I2C_FUNC_SMBUS_BYTE_DATA
+				     | I2C_FUNC_SMBUS_READ_I2C_BLOCK))
+		return -EOPNOTSUPP;
+
+	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;
+
+	data->wakeup_gpio = devm_gpiod_get_optional(&client->dev, "wakeup",
+						    GPIOD_OUT_HIGH);
+	if (IS_ERR(data->wakeup_gpio))
+		return PTR_ERR(data->wakeup_gpio);
+
+	ccs811_set_wakeup(data, true);
+
+	ret = ccs811_reset(client);
+	if (ret) {
+		ccs811_set_wakeup(data, false);
+		return ret;
+	}
+
+	/* Check hardware id (should be 0x81 for this family of devices) */
+	ret = i2c_smbus_read_byte_data(client, CCS811_HW_ID);
+	if (ret < 0) {
+		ccs811_set_wakeup(data, false);
+		return ret;
+	}
+
+	if (ret != CCS811_HW_ID_VALUE) {
+		dev_err(&client->dev, "hardware id doesn't match CCS81x\n");
+		ccs811_set_wakeup(data, false);
+		return -ENODEV;
+	}
+
+	ret = i2c_smbus_read_byte_data(client, CCS811_HW_VERSION);
+	if (ret < 0) {
+		ccs811_set_wakeup(data, false);
+		return ret;
+	}
+
+	if ((ret & CCS811_HW_VERSION_MASK) != CCS811_HW_VERSION_VALUE) {
+		dev_err(&client->dev, "no CCS811 sensor\n");
+		ccs811_set_wakeup(data, false);
+		return -ENODEV;
+	}
+
+	ret = ccs811_setup(client);
+	if (ret < 0) {
+		ccs811_set_wakeup(data, false);
+		return ret;
+	}
+
+	ccs811_set_wakeup(data, false);
+
+	mutex_init(&data->lock);
+
+	indio_dev->name = id->name;
+	indio_dev->info = &ccs811_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	indio_dev->channels = ccs811_channels;
+	indio_dev->num_channels = ARRAY_SIZE(ccs811_channels);
+
+	if (client->irq > 0) {
+		ret = devm_request_threaded_irq(&client->dev, client->irq,
+						ccs811_data_rdy_trigger_poll,
+						NULL,
+						IRQF_TRIGGER_FALLING |
+						IRQF_ONESHOT,
+						"ccs811_irq", indio_dev);
+		if (ret)
+			goto err_poweroff;
+
+		data->drdy_trig = devm_iio_trigger_alloc(&client->dev,
+							 "%s-dev%d",
+							 indio_dev->name,
+							 iio_device_id(indio_dev));
+		if (!data->drdy_trig) {
+			ret = -ENOMEM;
+			goto err_poweroff;
+		}
+
+		data->drdy_trig->ops = &ccs811_trigger_ops;
+		iio_trigger_set_drvdata(data->drdy_trig, indio_dev);
+		ret = iio_trigger_register(data->drdy_trig);
+		if (ret)
+			goto err_poweroff;
+
+		indio_dev->trig = iio_trigger_get(data->drdy_trig);
+	}
+
+	ret = iio_triggered_buffer_setup(indio_dev, NULL,
+					 ccs811_trigger_handler, NULL);
+
+	if (ret < 0) {
+		dev_err(&client->dev, "triggered buffer setup failed\n");
+		goto err_trigger_unregister;
+	}
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0) {
+		dev_err(&client->dev, "unable to register iio device\n");
+		goto err_buffer_cleanup;
+	}
+	return 0;
+
+err_buffer_cleanup:
+	iio_triggered_buffer_cleanup(indio_dev);
+err_trigger_unregister:
+	if (data->drdy_trig)
+		iio_trigger_unregister(data->drdy_trig);
+err_poweroff:
+	i2c_smbus_write_byte_data(client, CCS811_MEAS_MODE, CCS811_MODE_IDLE);
+
+	return ret;
+}
+
+static void ccs811_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct ccs811_data *data = iio_priv(indio_dev);
+	int ret;
+
+	iio_device_unregister(indio_dev);
+	iio_triggered_buffer_cleanup(indio_dev);
+	if (data->drdy_trig)
+		iio_trigger_unregister(data->drdy_trig);
+
+	ret = i2c_smbus_write_byte_data(client, CCS811_MEAS_MODE,
+					CCS811_MODE_IDLE);
+	if (ret)
+		dev_warn(&client->dev, "Failed to power down device (%pe)\n",
+			 ERR_PTR(ret));
+}
+
+static const struct i2c_device_id ccs811_id[] = {
+	{ .name = "ccs811" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ccs811_id);
+
+static const struct of_device_id ccs811_dt_ids[] = {
+	{ .compatible = "ams,ccs811" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ccs811_dt_ids);
+
+static struct i2c_driver ccs811_driver = {
+	.driver = {
+		.name = "ccs811",
+		.of_match_table = ccs811_dt_ids,
+	},
+	.probe = ccs811_probe,
+	.remove = ccs811_remove,
+	.id_table = ccs811_id,
+};
+module_i2c_driver(ccs811_driver);
+
+MODULE_AUTHOR("Narcisa Vasile <narcisaanamaria12@gmail.com>");
+MODULE_DESCRIPTION("CCS811 volatile organic compounds sensor");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/chemical/ens160.h b/drivers/iio/chemical/ens160.h
new file mode 100644
index 000000000..f9f0575ce
--- /dev/null
+++ b/drivers/iio/chemical/ens160.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef ENS160_H_
+#define ENS160_H_
+
+int devm_ens160_core_probe(struct device *dev, struct regmap *regmap, int irq,
+			   const char *name);
+
+extern const struct dev_pm_ops ens160_pm_ops;
+
+#endif
diff --git a/drivers/iio/chemical/ens160_core.c b/drivers/iio/chemical/ens160_core.c
new file mode 100644
index 000000000..7c1ffda38
--- /dev/null
+++ b/drivers/iio/chemical/ens160_core.c
@@ -0,0 +1,373 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ScioSense ENS160 multi-gas sensor driver
+ *
+ * Copyright (c) 2024 Gustavo Silva <gustavograzs@gmail.com>
+ *
+ * Datasheet:
+ *  https://www.sciosense.com/wp-content/uploads/2023/12/ENS160-Datasheet.pdf
+ */
+
+#include <linux/bitfield.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/module.h>
+#include <linux/regmap.h>
+
+#include "ens160.h"
+
+#define ENS160_PART_ID 0x160
+
+#define ENS160_BOOTING_TIME_MS 10U
+
+#define ENS160_REG_PART_ID		0x00
+
+#define ENS160_REG_OPMODE		0x10
+
+#define ENS160_REG_CONFIG		0x11
+#define ENS160_REG_CONFIG_INTEN		BIT(0)
+#define ENS160_REG_CONFIG_INTDAT	BIT(1)
+#define ENS160_REG_CONFIG_INT_CFG	BIT(5)
+
+#define ENS160_REG_MODE_DEEP_SLEEP	0x00
+#define ENS160_REG_MODE_IDLE		0x01
+#define ENS160_REG_MODE_STANDARD	0x02
+#define ENS160_REG_MODE_RESET		0xF0
+
+#define ENS160_REG_COMMAND		0x12
+#define ENS160_REG_COMMAND_GET_APPVER	0x0E
+#define ENS160_REG_COMMAND_CLRGPR	0xCC
+
+#define ENS160_REG_TEMP_IN		0x13
+#define ENS160_REG_RH_IN		0x15
+#define ENS160_REG_DEVICE_STATUS	0x20
+#define ENS160_REG_DATA_AQI		0x21
+#define ENS160_REG_DATA_TVOC		0x22
+#define ENS160_REG_DATA_ECO2		0x24
+#define ENS160_REG_DATA_T		0x30
+#define ENS160_REG_DATA_RH		0x32
+#define ENS160_REG_GPR_READ4		0x4C
+
+#define ENS160_STATUS_VALIDITY_FLAG	GENMASK(3, 2)
+
+#define ENS160_STATUS_NORMAL		0x00
+
+struct ens160_data {
+	struct regmap *regmap;
+	/* Protect reads from the sensor */
+	struct mutex mutex;
+	struct {
+		__le16 chans[2];
+		aligned_s64 timestamp;
+	} scan __aligned(IIO_DMA_MINALIGN);
+	u8 fw_version[3];
+	__le16 buf;
+};
+
+static const struct iio_chan_spec ens160_channels[] = {
+	{
+		.type = IIO_CONCENTRATION,
+		.channel2 = IIO_MOD_VOC,
+		.modified = 1,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE),
+		.address = ENS160_REG_DATA_TVOC,
+		.scan_index = 0,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_LE,
+		},
+	},
+	{
+		.type = IIO_CONCENTRATION,
+		.channel2 = IIO_MOD_CO2,
+		.modified = 1,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE),
+		.address = ENS160_REG_DATA_ECO2,
+		.scan_index = 1,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_LE,
+		},
+	},
+	IIO_CHAN_SOFT_TIMESTAMP(2),
+};
+
+static int __ens160_read_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int *val)
+{
+	struct ens160_data *data = iio_priv(indio_dev);
+	int ret;
+
+	guard(mutex)(&data->mutex);
+	ret = regmap_bulk_read(data->regmap, chan->address,
+			       &data->buf, sizeof(data->buf));
+	if (ret)
+		return ret;
+	*val = le16_to_cpu(data->buf);
+	return IIO_VAL_INT;
+}
+
+static int ens160_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val, int *val2, long mask)
+{
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		if (!iio_device_claim_direct(indio_dev))
+			return -EBUSY;
+		ret = __ens160_read_raw(indio_dev, chan, val);
+		iio_device_release_direct(indio_dev);
+		return ret;
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->channel2) {
+		case IIO_MOD_CO2:
+			/* The sensor reads CO2 data as ppm */
+			*val = 0;
+			*val2 = 100;
+			return IIO_VAL_INT_PLUS_MICRO;
+		case IIO_MOD_VOC:
+			/* The sensor reads VOC data as ppb */
+			*val = 0;
+			*val2 = 100;
+			return IIO_VAL_INT_PLUS_NANO;
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ens160_set_mode(struct ens160_data *data, u8 mode)
+{
+	int ret;
+
+	ret = regmap_write(data->regmap, ENS160_REG_OPMODE, mode);
+	if (ret)
+		return ret;
+
+	msleep(ENS160_BOOTING_TIME_MS);
+
+	return 0;
+}
+
+static void ens160_set_idle(void *data)
+{
+	ens160_set_mode(data, ENS160_REG_MODE_IDLE);
+}
+
+static int ens160_chip_init(struct ens160_data *data)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	unsigned int status;
+	int ret;
+
+	ret = ens160_set_mode(data, ENS160_REG_MODE_RESET);
+	if (ret)
+		return ret;
+
+	ret = regmap_bulk_read(data->regmap, ENS160_REG_PART_ID, &data->buf,
+			       sizeof(data->buf));
+	if (ret)
+		return ret;
+
+	if (le16_to_cpu(data->buf) != ENS160_PART_ID)
+		return -ENODEV;
+
+	ret = ens160_set_mode(data, ENS160_REG_MODE_IDLE);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(data->regmap, ENS160_REG_COMMAND,
+			   ENS160_REG_COMMAND_CLRGPR);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(data->regmap, ENS160_REG_COMMAND,
+			   ENS160_REG_COMMAND_GET_APPVER);
+	if (ret)
+		return ret;
+
+	ret = regmap_bulk_read(data->regmap, ENS160_REG_GPR_READ4,
+			       data->fw_version, sizeof(data->fw_version));
+	if (ret)
+		return ret;
+
+	dev_info(dev, "firmware version: %u.%u.%u\n", data->fw_version[2],
+		 data->fw_version[1], data->fw_version[0]);
+
+	ret = ens160_set_mode(data, ENS160_REG_MODE_STANDARD);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(dev, ens160_set_idle, data);
+	if (ret)
+		return ret;
+
+	ret = regmap_read(data->regmap, ENS160_REG_DEVICE_STATUS, &status);
+	if (ret)
+		return ret;
+
+	if (FIELD_GET(ENS160_STATUS_VALIDITY_FLAG, status)
+	    != ENS160_STATUS_NORMAL)
+		return -EINVAL;
+
+	return 0;
+}
+
+static const struct iio_info ens160_info = {
+	.read_raw = ens160_read_raw,
+};
+
+static int ens160_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ens160_data *data = iio_priv(indio_dev);
+
+	return ens160_set_mode(data, ENS160_REG_MODE_DEEP_SLEEP);
+}
+
+static int ens160_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ens160_data *data = iio_priv(indio_dev);
+	int ret;
+
+	ret = ens160_set_mode(data, ENS160_REG_MODE_IDLE);
+	if (ret)
+		return ret;
+
+	return ens160_set_mode(data, ENS160_REG_MODE_STANDARD);
+}
+EXPORT_NS_SIMPLE_DEV_PM_OPS(ens160_pm_ops, ens160_suspend, ens160_resume,
+			    IIO_ENS160);
+
+static irqreturn_t ens160_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct ens160_data *data = iio_priv(indio_dev);
+	int ret;
+
+	guard(mutex)(&data->mutex);
+
+	ret = regmap_bulk_read(data->regmap, ENS160_REG_DATA_TVOC,
+			       data->scan.chans, sizeof(data->scan.chans));
+	if (ret)
+		goto err;
+
+	iio_push_to_buffers_with_ts(indio_dev, &data->scan, sizeof(data->scan),
+				    pf->timestamp);
+err:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int ens160_set_trigger_state(struct iio_trigger *trig, bool state)
+{
+	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+	struct ens160_data *data = iio_priv(indio_dev);
+	unsigned int int_bits = ENS160_REG_CONFIG_INTEN |
+				ENS160_REG_CONFIG_INTDAT |
+				ENS160_REG_CONFIG_INT_CFG;
+
+	if (state)
+		return regmap_set_bits(data->regmap, ENS160_REG_CONFIG,
+				       int_bits);
+	else
+		return regmap_clear_bits(data->regmap, ENS160_REG_CONFIG,
+					 int_bits);
+}
+
+static const struct iio_trigger_ops ens160_trigger_ops = {
+	.set_trigger_state = ens160_set_trigger_state,
+	.validate_device = iio_trigger_validate_own_device,
+};
+
+static int ens160_setup_trigger(struct iio_dev *indio_dev, int irq)
+{
+	struct device *dev = indio_dev->dev.parent;
+	struct iio_trigger *trig;
+	int ret;
+
+	trig = devm_iio_trigger_alloc(dev, "%s-dev%d", indio_dev->name,
+				      iio_device_id(indio_dev));
+	if (!trig)
+		return -ENOMEM;
+
+	trig->ops = &ens160_trigger_ops;
+	iio_trigger_set_drvdata(trig, indio_dev);
+
+	ret = devm_iio_trigger_register(dev, trig);
+	if (ret)
+		return ret;
+
+	indio_dev->trig = iio_trigger_get(trig);
+
+	ret = devm_request_irq(dev, irq, iio_trigger_generic_data_rdy_poll,
+			       IRQF_NO_THREAD, indio_dev->name,
+			       indio_dev->trig);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+int devm_ens160_core_probe(struct device *dev, struct regmap *regmap, int irq,
+			   const char *name)
+{
+	struct ens160_data *data;
+	struct iio_dev *indio_dev;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	data->regmap = regmap;
+
+	indio_dev->name = name;
+	indio_dev->info = &ens160_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = ens160_channels;
+	indio_dev->num_channels = ARRAY_SIZE(ens160_channels);
+
+	if (irq > 0) {
+		ret = ens160_setup_trigger(indio_dev, irq);
+		if (ret)
+			return dev_err_probe(dev, ret,
+					     "failed to setup trigger\n");
+	}
+
+	ret = ens160_chip_init(data);
+	if (ret)
+		return dev_err_probe(dev, ret, "chip initialization failed\n");
+
+	mutex_init(&data->mutex);
+
+	ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
+					      iio_pollfunc_store_time,
+					      ens160_trigger_handler, NULL);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+EXPORT_SYMBOL_NS(devm_ens160_core_probe, "IIO_ENS160");
+
+MODULE_AUTHOR("Gustavo Silva <gustavograzs@gmail.com>");
+MODULE_DESCRIPTION("ScioSense ENS160 driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/chemical/ens160_i2c.c b/drivers/iio/chemical/ens160_i2c.c
new file mode 100644
index 000000000..ab0e8dcce
--- /dev/null
+++ b/drivers/iio/chemical/ens160_i2c.c
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ScioSense ENS160 multi-gas sensor I2C driver
+ *
+ * Copyright (c) 2024 Gustavo Silva <gustavograzs@gmail.com>
+ *
+ * 7-Bit I2C slave address is:
+ *	- 0x52 if ADDR pin LOW
+ *	- 0x53 if ADDR pin HIGH
+ */
+
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include "ens160.h"
+
+static const struct regmap_config ens160_regmap_i2c_conf = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static int ens160_i2c_probe(struct i2c_client *client)
+{
+	struct regmap *regmap;
+
+	regmap = devm_regmap_init_i2c(client, &ens160_regmap_i2c_conf);
+	if (IS_ERR(regmap))
+		return dev_err_probe(&client->dev, PTR_ERR(regmap),
+				     "Failed to register i2c regmap\n");
+
+	return devm_ens160_core_probe(&client->dev, regmap, client->irq,
+				      "ens160");
+}
+
+static const struct i2c_device_id ens160_i2c_id[] = {
+	{ .name = "ens160" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ens160_i2c_id);
+
+static const struct of_device_id ens160_of_i2c_match[] = {
+	{ .compatible = "sciosense,ens160" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ens160_of_i2c_match);
+
+static struct i2c_driver ens160_i2c_driver = {
+	.driver = {
+		.name		= "ens160",
+		.of_match_table	= ens160_of_i2c_match,
+		.pm		= pm_sleep_ptr(&ens160_pm_ops),
+	},
+	.probe = ens160_i2c_probe,
+	.id_table = ens160_i2c_id,
+};
+module_i2c_driver(ens160_i2c_driver);
+
+MODULE_AUTHOR("Gustavo Silva <gustavograzs@gmail.com>");
+MODULE_DESCRIPTION("ScioSense ENS160 I2C driver");
+MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS("IIO_ENS160");
diff --git a/drivers/iio/chemical/ens160_spi.c b/drivers/iio/chemical/ens160_spi.c
new file mode 100644
index 000000000..7c11d1929
--- /dev/null
+++ b/drivers/iio/chemical/ens160_spi.c
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ScioSense ENS160 multi-gas sensor SPI driver
+ *
+ * Copyright (c) 2024 Gustavo Silva <gustavograzs@gmail.com>
+ */
+
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+
+#include "ens160.h"
+
+#define ENS160_SPI_READ BIT(0)
+
+static const struct regmap_config ens160_regmap_spi_conf = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.reg_shift = -1,
+	.read_flag_mask = ENS160_SPI_READ,
+};
+
+static int ens160_spi_probe(struct spi_device *spi)
+{
+	struct regmap *regmap;
+
+	regmap = devm_regmap_init_spi(spi, &ens160_regmap_spi_conf);
+	if (IS_ERR(regmap))
+		return dev_err_probe(&spi->dev, PTR_ERR(regmap),
+				     "Failed to register spi regmap\n");
+
+	return devm_ens160_core_probe(&spi->dev, regmap, spi->irq, "ens160");
+}
+
+static const struct of_device_id ens160_spi_of_match[] = {
+	{ .compatible = "sciosense,ens160" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ens160_spi_of_match);
+
+static const struct spi_device_id ens160_spi_id[] = {
+	{ .name = "ens160" },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, ens160_spi_id);
+
+static struct spi_driver ens160_spi_driver = {
+	.driver = {
+		.name	= "ens160",
+		.of_match_table = ens160_spi_of_match,
+		.pm = pm_sleep_ptr(&ens160_pm_ops),
+	},
+	.probe		= ens160_spi_probe,
+	.id_table	= ens160_spi_id,
+};
+module_spi_driver(ens160_spi_driver);
+
+MODULE_AUTHOR("Gustavo Silva <gustavograzs@gmail.com>");
+MODULE_DESCRIPTION("ScioSense ENS160 SPI driver");
+MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS("IIO_ENS160");
diff --git a/drivers/iio/chemical/mhz19b.c b/drivers/iio/chemical/mhz19b.c
new file mode 100644
index 000000000..a793620e9
--- /dev/null
+++ b/drivers/iio/chemical/mhz19b.c
@@ -0,0 +1,332 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * mh-z19b CO₂ sensor driver
+ *
+ * Copyright (c) 2025 Gyeyoung Baek <gye976@gmail.com>
+ *
+ * Datasheet:
+ * https://www.winsen-sensor.com/d/files/infrared-gas-sensor/mh-z19b-co2-ver1_0.pdf
+ */
+
+#include <linux/array_size.h>
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/jiffies.h>
+#include <linux/kstrtox.h>
+#include <linux/minmax.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <linux/serdev.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/unaligned.h>
+
+/*
+ * Commands have following format:
+ *
+ * +------+------+-----+------+------+------+------+------+-------+
+ * | 0xFF | 0x01 | cmd | arg0 | arg1 | 0x00 | 0x00 | 0x00 | cksum |
+ * +------+------+-----+------+------+------+------+------+-------+
+ */
+#define MHZ19B_CMD_SIZE 9
+
+/* ABC logic in MHZ19B means auto calibration. */
+#define MHZ19B_ABC_LOGIC_CMD		0x79
+#define MHZ19B_READ_CO2_CMD		0x86
+#define MHZ19B_SPAN_POINT_CMD		0x88
+#define MHZ19B_ZERO_POINT_CMD		0x87
+
+#define MHZ19B_SPAN_POINT_PPM_MIN	1000
+#define MHZ19B_SPAN_POINT_PPM_MAX	5000
+
+#define MHZ19B_SERDEV_TIMEOUT msecs_to_jiffies(100)
+
+struct mhz19b_state {
+	struct serdev_device *serdev;
+
+	/* Must wait until the 'buf' is filled with 9 bytes.*/
+	struct completion buf_ready;
+
+	u8 buf_idx;
+	bool buf_overflow;
+
+	/*
+	 * Serdev receive buffer.
+	 * When data is received from the MH-Z19B,
+	 * the 'mhz19b_receive_buf' callback function is called and fills this buffer.
+	 */
+	u8 buf[MHZ19B_CMD_SIZE] __aligned(IIO_DMA_MINALIGN);
+};
+
+static u8 mhz19b_get_checksum(u8 *cmd_buf)
+{
+	u8 i, checksum = 0;
+
+/*
+ * +------+------+-----+------+------+------+------+------+-------+
+ * | 0xFF | 0x01 | cmd | arg0 | arg1 | 0x00 | 0x00 | 0x00 | cksum |
+ * +------+------+-----+------+------+------+------+------+-------+
+ *	     i:1    2      3      4      5      6      7
+ *
+ *  Sum all cmd_buf elements from index 1 to 7.
+ */
+	for (i = 1; i < 8; i++)
+		checksum += cmd_buf[i];
+
+	return -checksum;
+}
+
+static int mhz19b_serdev_cmd(struct iio_dev *indio_dev, int cmd, u16 arg)
+{
+	struct mhz19b_state *st = iio_priv(indio_dev);
+	struct serdev_device *serdev = st->serdev;
+	struct device *dev = &indio_dev->dev;
+	int ret;
+
+	/*
+	 * cmd_buf[3,4] : arg0,1
+	 * cmd_buf[8]	: checksum
+	 */
+	u8 cmd_buf[MHZ19B_CMD_SIZE] = {
+		0xFF, 0x01, cmd,
+	};
+
+	switch (cmd) {
+	case MHZ19B_ABC_LOGIC_CMD:
+		cmd_buf[3] = arg ? 0xA0 : 0;
+		break;
+	case MHZ19B_SPAN_POINT_CMD:
+		put_unaligned_be16(arg, &cmd_buf[3]);
+		break;
+	default:
+		break;
+	}
+	cmd_buf[8] = mhz19b_get_checksum(cmd_buf);
+
+	/* Write buf to uart ctrl synchronously */
+	st->buf_idx = 0;
+	st->buf_overflow = false;
+	reinit_completion(&st->buf_ready);
+
+	ret = serdev_device_write(serdev, cmd_buf, MHZ19B_CMD_SIZE, 0);
+	if (ret < 0)
+		return ret;
+	if (ret != MHZ19B_CMD_SIZE)
+		return -EIO;
+
+	switch (cmd) {
+	case MHZ19B_READ_CO2_CMD:
+		ret = wait_for_completion_interruptible_timeout(&st->buf_ready,
+			MHZ19B_SERDEV_TIMEOUT);
+		if (ret < 0)
+			return ret;
+		if (!ret)
+			return -ETIMEDOUT;
+
+		if (st->buf_overflow)
+			return -EMSGSIZE;
+
+		if (st->buf[8] != mhz19b_get_checksum(st->buf)) {
+			dev_err(dev, "checksum err");
+			return -EINVAL;
+		}
+
+		return get_unaligned_be16(&st->buf[2]);
+	default:
+		/* No response commands. */
+		return 0;
+	}
+}
+
+static int mhz19b_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val, int *val2, long mask)
+{
+	int ret;
+
+	ret = mhz19b_serdev_cmd(indio_dev, MHZ19B_READ_CO2_CMD, 0);
+	if (ret < 0)
+		return ret;
+
+	*val = ret;
+	return IIO_VAL_INT;
+}
+
+/*
+ * echo 0 > calibration_auto_enable : ABC logic off
+ * echo 1 > calibration_auto_enable : ABC logic on
+ */
+static ssize_t calibration_auto_enable_store(struct device *dev,
+					     struct device_attribute *attr,
+					     const char *buf, size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	bool enable;
+	int ret;
+
+	ret = kstrtobool(buf, &enable);
+	if (ret)
+		return ret;
+
+	ret = mhz19b_serdev_cmd(indio_dev, MHZ19B_ABC_LOGIC_CMD, enable);
+	if (ret < 0)
+		return ret;
+
+	return len;
+}
+static IIO_DEVICE_ATTR_WO(calibration_auto_enable, 0);
+
+/*
+ * echo 0 > calibration_forced_value		 : zero point calibration
+ *	(make sure the sensor has been working under 400ppm for over 20 minutes.)
+ * echo [1000 1 5000] > calibration_forced_value : span point calibration
+ *	(make sure the sensor has been working under a certain level CO₂ for over 20 minutes.)
+ */
+static ssize_t calibration_forced_value_store(struct device *dev,
+					      struct device_attribute *attr,
+					      const char *buf, size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	u16 ppm;
+	int cmd, ret;
+
+	ret = kstrtou16(buf, 0, &ppm);
+	if (ret)
+		return ret;
+
+	if (ppm) {
+		if (!in_range(ppm, MHZ19B_SPAN_POINT_PPM_MIN,
+			MHZ19B_SPAN_POINT_PPM_MAX - MHZ19B_SPAN_POINT_PPM_MIN + 1)) {
+			dev_dbg(&indio_dev->dev,
+				"span point ppm should be in a range [%d-%d]\n",
+				MHZ19B_SPAN_POINT_PPM_MIN, MHZ19B_SPAN_POINT_PPM_MAX);
+			return -EINVAL;
+		}
+
+		cmd = MHZ19B_SPAN_POINT_CMD;
+	} else {
+		cmd = MHZ19B_ZERO_POINT_CMD;
+	}
+
+	ret = mhz19b_serdev_cmd(indio_dev, cmd, ppm);
+	if (ret < 0)
+		return ret;
+
+	return len;
+}
+static IIO_DEVICE_ATTR_WO(calibration_forced_value, 0);
+
+static struct attribute *mhz19b_attrs[] = {
+	&iio_dev_attr_calibration_auto_enable.dev_attr.attr,
+	&iio_dev_attr_calibration_forced_value.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group mhz19b_attr_group = {
+	.attrs = mhz19b_attrs,
+};
+
+static const struct iio_info mhz19b_info = {
+	.attrs = &mhz19b_attr_group,
+	.read_raw = mhz19b_read_raw,
+};
+
+static const struct iio_chan_spec mhz19b_channels[] = {
+	{
+		.type = IIO_CONCENTRATION,
+		.channel2 = IIO_MOD_CO2,
+		.modified = 1,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+	},
+};
+
+static size_t mhz19b_receive_buf(struct serdev_device *serdev,
+			      const u8 *data, size_t len)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(&serdev->dev);
+	struct mhz19b_state *st = iio_priv(indio_dev);
+	size_t remaining = MHZ19B_CMD_SIZE - st->buf_idx;
+
+	if (len > remaining) {
+		st->buf_idx = 0;
+		st->buf_overflow = true;
+		complete(&st->buf_ready);
+		return len;
+	}
+
+	memcpy(st->buf + st->buf_idx, data, len);
+	st->buf_idx += len;
+
+	if (st->buf_idx == MHZ19B_CMD_SIZE) {
+		st->buf_idx = 0;
+		complete(&st->buf_ready);
+	}
+
+	return len;
+}
+
+static const struct serdev_device_ops mhz19b_ops = {
+	.receive_buf = mhz19b_receive_buf,
+	.write_wakeup = serdev_device_write_wakeup,
+};
+
+static int mhz19b_probe(struct serdev_device *serdev)
+{
+	int ret;
+	struct device *dev = &serdev->dev;
+	struct iio_dev *indio_dev;
+	struct mhz19b_state *st;
+
+	serdev_device_set_client_ops(serdev, &mhz19b_ops);
+	ret = devm_serdev_device_open(dev, serdev);
+	if (ret)
+		return ret;
+	serdev_device_set_baudrate(serdev, 9600);
+	serdev_device_set_flow_control(serdev, false);
+	ret = serdev_device_set_parity(serdev, SERDEV_PARITY_NONE);
+	if (ret)
+		return ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+	serdev_device_set_drvdata(serdev, indio_dev);
+
+	st = iio_priv(indio_dev);
+	st->serdev = serdev;
+
+	init_completion(&st->buf_ready);
+
+	ret = devm_regulator_get_enable(dev, "vin");
+	if (ret)
+		return ret;
+
+	indio_dev->name = "mh-z19b";
+	indio_dev->channels = mhz19b_channels;
+	indio_dev->num_channels = ARRAY_SIZE(mhz19b_channels);
+	indio_dev->info = &mhz19b_info;
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct of_device_id mhz19b_of_match[] = {
+	{ .compatible = "winsen,mhz19b", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, mhz19b_of_match);
+
+static struct serdev_device_driver mhz19b_driver = {
+	.driver = {
+		.name = "mhz19b",
+		.of_match_table = mhz19b_of_match,
+	},
+	.probe = mhz19b_probe,
+};
+module_serdev_device_driver(mhz19b_driver);
+
+MODULE_AUTHOR("Gyeyoung Baek");
+MODULE_DESCRIPTION("MH-Z19B CO2 sensor driver using serdev interface");
+MODULE_LICENSE("GPL");
diff --git a/drivers/iio/chemical/pms7003.c b/drivers/iio/chemical/pms7003.c
new file mode 100644
index 000000000..c50edb24a
--- /dev/null
+++ b/drivers/iio/chemical/pms7003.c
@@ -0,0 +1,351 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Plantower PMS7003 particulate matter sensor driver
+ *
+ * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
+ */
+
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/serdev.h>
+#include <linux/types.h>
+#include <linux/unaligned.h>
+
+#define PMS7003_DRIVER_NAME "pms7003"
+
+#define PMS7003_MAGIC 0x424d
+/* last 2 data bytes hold frame checksum */
+#define PMS7003_MAX_DATA_LENGTH 28
+#define PMS7003_CHECKSUM_LENGTH 2
+#define PMS7003_PM10_OFFSET 10
+#define PMS7003_PM2P5_OFFSET 8
+#define PMS7003_PM1_OFFSET 6
+
+#define PMS7003_TIMEOUT msecs_to_jiffies(6000)
+#define PMS7003_CMD_LENGTH 7
+#define PMS7003_PM_MAX 1000
+#define PMS7003_PM_MIN 0
+
+enum {
+	PM1,
+	PM2P5,
+	PM10,
+};
+
+enum pms7003_cmd {
+	CMD_WAKEUP,
+	CMD_ENTER_PASSIVE_MODE,
+	CMD_READ_PASSIVE,
+	CMD_SLEEP,
+};
+
+/*
+ * commands have following format:
+ *
+ * +------+------+-----+------+-----+-----------+-----------+
+ * | 0x42 | 0x4d | cmd | 0x00 | arg | cksum msb | cksum lsb |
+ * +------+------+-----+------+-----+-----------+-----------+
+ */
+static const u8 pms7003_cmd_tbl[][PMS7003_CMD_LENGTH] = {
+	[CMD_WAKEUP] = { 0x42, 0x4d, 0xe4, 0x00, 0x01, 0x01, 0x74 },
+	[CMD_ENTER_PASSIVE_MODE] = { 0x42, 0x4d, 0xe1, 0x00, 0x00, 0x01, 0x70 },
+	[CMD_READ_PASSIVE] = { 0x42, 0x4d, 0xe2, 0x00, 0x00, 0x01, 0x71 },
+	[CMD_SLEEP] = { 0x42, 0x4d, 0xe4, 0x00, 0x00, 0x01, 0x73 },
+};
+
+struct pms7003_frame {
+	u8 data[PMS7003_MAX_DATA_LENGTH];
+	u16 expected_length;
+	u16 length;
+};
+
+struct pms7003_state {
+	struct serdev_device *serdev;
+	struct pms7003_frame frame;
+	struct completion frame_ready;
+	struct mutex lock; /* must be held whenever state gets touched */
+	/* Used to construct scan to push to the IIO buffer */
+	struct {
+		u16 data[3]; /* PM1, PM2P5, PM10 */
+		aligned_s64 ts;
+	} scan;
+};
+
+static int pms7003_do_cmd(struct pms7003_state *state, enum pms7003_cmd cmd)
+{
+	int ret;
+
+	ret = serdev_device_write(state->serdev, pms7003_cmd_tbl[cmd],
+				  PMS7003_CMD_LENGTH, PMS7003_TIMEOUT);
+	if (ret < PMS7003_CMD_LENGTH)
+		return ret < 0 ? ret : -EIO;
+
+	ret = wait_for_completion_interruptible_timeout(&state->frame_ready,
+							PMS7003_TIMEOUT);
+	if (!ret)
+		ret = -ETIMEDOUT;
+
+	return ret < 0 ? ret : 0;
+}
+
+static u16 pms7003_get_pm(const u8 *data)
+{
+	return clamp_val(get_unaligned_be16(data),
+			 PMS7003_PM_MIN, PMS7003_PM_MAX);
+}
+
+static irqreturn_t pms7003_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct pms7003_state *state = iio_priv(indio_dev);
+	struct pms7003_frame *frame = &state->frame;
+	int ret;
+
+	mutex_lock(&state->lock);
+	ret = pms7003_do_cmd(state, CMD_READ_PASSIVE);
+	if (ret) {
+		mutex_unlock(&state->lock);
+		goto err;
+	}
+
+	state->scan.data[PM1] =
+		pms7003_get_pm(frame->data + PMS7003_PM1_OFFSET);
+	state->scan.data[PM2P5] =
+		pms7003_get_pm(frame->data + PMS7003_PM2P5_OFFSET);
+	state->scan.data[PM10] =
+		pms7003_get_pm(frame->data + PMS7003_PM10_OFFSET);
+	mutex_unlock(&state->lock);
+
+	iio_push_to_buffers_with_ts(indio_dev, &state->scan, sizeof(state->scan),
+				    iio_get_time_ns(indio_dev));
+err:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int pms7003_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int *val, int *val2, long mask)
+{
+	struct pms7003_state *state = iio_priv(indio_dev);
+	struct pms7003_frame *frame = &state->frame;
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_PROCESSED:
+		switch (chan->type) {
+		case IIO_MASSCONCENTRATION:
+			mutex_lock(&state->lock);
+			ret = pms7003_do_cmd(state, CMD_READ_PASSIVE);
+			if (ret) {
+				mutex_unlock(&state->lock);
+				return ret;
+			}
+
+			*val = pms7003_get_pm(frame->data + chan->address);
+			mutex_unlock(&state->lock);
+
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static const struct iio_info pms7003_info = {
+	.read_raw = pms7003_read_raw,
+};
+
+#define PMS7003_CHAN(_index, _mod, _addr) { \
+	.type = IIO_MASSCONCENTRATION, \
+	.modified = 1, \
+	.channel2 = IIO_MOD_ ## _mod, \
+	.address = _addr, \
+	.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
+	.scan_index = _index, \
+	.scan_type = { \
+		.sign = 'u', \
+		.realbits = 10, \
+		.storagebits = 16, \
+		.endianness = IIO_CPU, \
+	}, \
+}
+
+static const struct iio_chan_spec pms7003_channels[] = {
+	PMS7003_CHAN(0, PM1, PMS7003_PM1_OFFSET),
+	PMS7003_CHAN(1, PM2P5, PMS7003_PM2P5_OFFSET),
+	PMS7003_CHAN(2, PM10, PMS7003_PM10_OFFSET),
+	IIO_CHAN_SOFT_TIMESTAMP(3),
+};
+
+static u16 pms7003_calc_checksum(struct pms7003_frame *frame)
+{
+	u16 checksum = (PMS7003_MAGIC >> 8) + (u8)(PMS7003_MAGIC & 0xff) +
+		       (frame->length >> 8) + (u8)frame->length;
+	int i;
+
+	for (i = 0; i < frame->length - PMS7003_CHECKSUM_LENGTH; i++)
+		checksum += frame->data[i];
+
+	return checksum;
+}
+
+static bool pms7003_frame_is_okay(struct pms7003_frame *frame)
+{
+	int offset = frame->length - PMS7003_CHECKSUM_LENGTH;
+	u16 checksum = get_unaligned_be16(frame->data + offset);
+
+	return checksum == pms7003_calc_checksum(frame);
+}
+
+static size_t pms7003_receive_buf(struct serdev_device *serdev, const u8 *buf,
+				  size_t size)
+{
+	struct iio_dev *indio_dev = serdev_device_get_drvdata(serdev);
+	struct pms7003_state *state = iio_priv(indio_dev);
+	struct pms7003_frame *frame = &state->frame;
+	size_t num;
+
+	if (!frame->expected_length) {
+		u16 magic;
+
+		/* wait for SOF and data length */
+		if (size < 4)
+			return 0;
+
+		magic = get_unaligned_be16(buf);
+		if (magic != PMS7003_MAGIC)
+			return 2;
+
+		num = get_unaligned_be16(buf + 2);
+		if (num <= PMS7003_MAX_DATA_LENGTH) {
+			frame->expected_length = num;
+			frame->length = 0;
+		}
+
+		return 4;
+	}
+
+	num = min(size, (size_t)(frame->expected_length - frame->length));
+	memcpy(frame->data + frame->length, buf, num);
+	frame->length += num;
+
+	if (frame->length == frame->expected_length) {
+		if (pms7003_frame_is_okay(frame))
+			complete(&state->frame_ready);
+
+		frame->expected_length = 0;
+	}
+
+	return num;
+}
+
+static const struct serdev_device_ops pms7003_serdev_ops = {
+	.receive_buf = pms7003_receive_buf,
+	.write_wakeup = serdev_device_write_wakeup,
+};
+
+static void pms7003_stop(void *data)
+{
+	struct pms7003_state *state = data;
+
+	pms7003_do_cmd(state, CMD_SLEEP);
+}
+
+static const unsigned long pms7003_scan_masks[] = { 0x07, 0x00 };
+
+static int pms7003_probe(struct serdev_device *serdev)
+{
+	struct pms7003_state *state;
+	struct iio_dev *indio_dev;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&serdev->dev, sizeof(*state));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	state = iio_priv(indio_dev);
+	serdev_device_set_drvdata(serdev, indio_dev);
+	state->serdev = serdev;
+	indio_dev->info = &pms7003_info;
+	indio_dev->name = PMS7003_DRIVER_NAME;
+	indio_dev->channels = pms7003_channels;
+	indio_dev->num_channels = ARRAY_SIZE(pms7003_channels);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->available_scan_masks = pms7003_scan_masks;
+
+	mutex_init(&state->lock);
+	init_completion(&state->frame_ready);
+
+	serdev_device_set_client_ops(serdev, &pms7003_serdev_ops);
+	ret = devm_serdev_device_open(&serdev->dev, serdev);
+	if (ret)
+		return ret;
+
+	serdev_device_set_baudrate(serdev, 9600);
+	serdev_device_set_flow_control(serdev, false);
+
+	ret = serdev_device_set_parity(serdev, SERDEV_PARITY_NONE);
+	if (ret)
+		return ret;
+
+	ret = pms7003_do_cmd(state, CMD_WAKEUP);
+	if (ret) {
+		dev_err(&serdev->dev, "failed to wakeup sensor\n");
+		return ret;
+	}
+
+	ret = pms7003_do_cmd(state, CMD_ENTER_PASSIVE_MODE);
+	if (ret) {
+		dev_err(&serdev->dev, "failed to enter passive mode\n");
+		return ret;
+	}
+
+	ret = devm_add_action_or_reset(&serdev->dev, pms7003_stop, state);
+	if (ret)
+		return ret;
+
+	ret = devm_iio_triggered_buffer_setup(&serdev->dev, indio_dev, NULL,
+					      pms7003_trigger_handler, NULL);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(&serdev->dev, indio_dev);
+}
+
+static const struct of_device_id pms7003_of_match[] = {
+	{ .compatible = "plantower,pms1003" },
+	{ .compatible = "plantower,pms3003" },
+	{ .compatible = "plantower,pms5003" },
+	{ .compatible = "plantower,pms6003" },
+	{ .compatible = "plantower,pms7003" },
+	{ .compatible = "plantower,pmsa003" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, pms7003_of_match);
+
+static struct serdev_device_driver pms7003_driver = {
+	.driver = {
+		.name = PMS7003_DRIVER_NAME,
+		.of_match_table = pms7003_of_match,
+	},
+	.probe = pms7003_probe,
+};
+module_serdev_device_driver(pms7003_driver);
+
+MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
+MODULE_DESCRIPTION("Plantower PMS7003 particulate matter sensor driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/chemical/scd30.h b/drivers/iio/chemical/scd30.h
new file mode 100644
index 000000000..1ac9f3f79
--- /dev/null
+++ b/drivers/iio/chemical/scd30.h
@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _SCD30_H
+#define _SCD30_H
+
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/mutex.h>
+#include <linux/pm.h>
+#include <linux/regulator/consumer.h>
+#include <linux/types.h>
+
+struct scd30_state;
+
+enum scd30_cmd {
+	/* start continuous measurement with pressure compensation */
+	CMD_START_MEAS,
+	/* stop continuous measurement */
+	CMD_STOP_MEAS,
+	/* set/get measurement interval */
+	CMD_MEAS_INTERVAL,
+	/* check whether new measurement is ready */
+	CMD_MEAS_READY,
+	/* get measurement */
+	CMD_READ_MEAS,
+	/* turn on/off automatic self calibration */
+	CMD_ASC,
+	/* set/get forced recalibration value */
+	CMD_FRC,
+	/* set/get temperature offset */
+	CMD_TEMP_OFFSET,
+	/* get firmware version */
+	CMD_FW_VERSION,
+	/* reset sensor */
+	CMD_RESET,
+	/*
+	 * Command for altitude compensation was omitted intentionally because
+	 * the same can be achieved by means of CMD_START_MEAS which takes
+	 * pressure above the sea level as an argument.
+	 */
+};
+
+#define SCD30_MEAS_COUNT 3
+
+typedef int (*scd30_command_t)(struct scd30_state *state, enum scd30_cmd cmd, u16 arg,
+			       void *response, int size);
+
+struct scd30_state {
+	/* serialize access to the device */
+	struct mutex lock;
+	struct device *dev;
+	struct regulator *vdd;
+	struct completion meas_ready;
+	/*
+	 * priv pointer is solely for serdev driver private data. We keep it
+	 * here because driver_data inside dev has been already used for iio and
+	 * struct serdev_device doesn't have one.
+	 */
+	void *priv;
+	int irq;
+	/*
+	 * no way to retrieve current ambient pressure compensation value from
+	 * the sensor so keep one around
+	 */
+	u16 pressure_comp;
+	u16 meas_interval;
+	int meas[SCD30_MEAS_COUNT];
+
+	scd30_command_t command;
+};
+
+extern const struct dev_pm_ops scd30_pm_ops;
+
+int scd30_probe(struct device *dev, int irq, const char *name, void *priv, scd30_command_t command);
+
+#endif
diff --git a/drivers/iio/chemical/scd30_core.c b/drivers/iio/chemical/scd30_core.c
new file mode 100644
index 000000000..770571c21
--- /dev/null
+++ b/drivers/iio/chemical/scd30_core.c
@@ -0,0 +1,779 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Sensirion SCD30 carbon dioxide sensor core driver
+ *
+ * Copyright (c) 2020 Tomasz Duszynski <tduszyns@gmail.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/cleanup.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/iio/buffer.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>
+#include <linux/iio/types.h>
+#include <linux/interrupt.h>
+#include <linux/irqreturn.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/regulator/consumer.h>
+#include <linux/string.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+#include <asm/byteorder.h>
+
+#include "scd30.h"
+
+#define SCD30_PRESSURE_COMP_MIN_MBAR 700
+#define SCD30_PRESSURE_COMP_MAX_MBAR 1400
+#define SCD30_PRESSURE_COMP_DEFAULT 1013
+#define SCD30_MEAS_INTERVAL_MIN_S 2
+#define SCD30_MEAS_INTERVAL_MAX_S 1800
+#define SCD30_MEAS_INTERVAL_DEFAULT SCD30_MEAS_INTERVAL_MIN_S
+#define SCD30_FRC_MIN_PPM 400
+#define SCD30_FRC_MAX_PPM 2000
+#define SCD30_TEMP_OFFSET_MAX 655360
+#define SCD30_EXTRA_TIMEOUT_PER_S 250
+
+/* Floating point arithmetic macros */
+#define SCD30_FLOAT_MANTISSA_MSK GENMASK(22, 0)
+#define SCD30_FLOAT_EXP_MSK GENMASK(30, 23)
+#define SCD30_FLOAT_SIGN_MSK BIT(31)
+
+enum {
+	SCD30_CONC,
+	SCD30_TEMP,
+	SCD30_HR,
+};
+
+static int scd30_command_write(struct scd30_state *state, enum scd30_cmd cmd, u16 arg)
+{
+	return state->command(state, cmd, arg, NULL, 0);
+}
+
+static int scd30_command_read(struct scd30_state *state, enum scd30_cmd cmd, u16 *val)
+{
+	__be16 tmp;
+	int ret;
+
+	ret = state->command(state, cmd, 0, &tmp, sizeof(tmp));
+	*val = be16_to_cpup(&tmp);
+
+	return ret;
+}
+
+static int scd30_reset(struct scd30_state *state)
+{
+	int ret;
+	u16 val;
+
+	ret = scd30_command_write(state, CMD_RESET, 0);
+	if (ret)
+		return ret;
+
+	/* sensor boots up within 2 secs */
+	msleep(2000);
+	/*
+	 * Power-on-reset causes sensor to produce some glitch on i2c bus and
+	 * some controllers end up in error state. Try to recover by placing
+	 * any data on the bus.
+	 */
+	scd30_command_read(state, CMD_MEAS_READY, &val);
+
+	return 0;
+}
+
+/* simplified float to fixed point conversion with a scaling factor of 0.01 */
+static int scd30_float_to_fp(int float32)
+{
+	int fraction, shift, sign;
+	int mantissa = FIELD_GET(SCD30_FLOAT_MANTISSA_MSK, float32);
+	int exp = FIELD_GET(SCD30_FLOAT_EXP_MSK, float32);
+
+	if (float32 & SCD30_FLOAT_SIGN_MSK)
+		sign = -1;
+	else
+		sign = 1;
+
+	/* special case 0 */
+	if (!exp && !mantissa)
+		return 0;
+
+	exp -= 127;
+	if (exp < 0) {
+		exp = -exp;
+		/* return values ranging from 1 to 99 */
+		return sign * ((((BIT(23) + mantissa) * 100) >> 23) >> exp);
+	}
+
+	/* return values starting at 100 */
+	shift = 23 - exp;
+	float32 = BIT(exp) + (mantissa >> shift);
+	fraction = mantissa & GENMASK(shift - 1, 0);
+
+	return sign * (float32 * 100 + ((fraction * 100) >> shift));
+}
+
+static int scd30_read_meas(struct scd30_state *state)
+{
+	int i, ret;
+
+	ret = state->command(state, CMD_READ_MEAS, 0, state->meas, sizeof(state->meas));
+	if (ret)
+		return ret;
+
+	be32_to_cpu_array(state->meas, (__be32 *)state->meas, ARRAY_SIZE(state->meas));
+
+	for (i = 0; i < ARRAY_SIZE(state->meas); i++)
+		state->meas[i] = scd30_float_to_fp(state->meas[i]);
+
+	/*
+	 * co2 is left unprocessed while temperature and humidity are scaled
+	 * to milli deg C and milli percent respectively.
+	 */
+	state->meas[SCD30_TEMP] *= 10;
+	state->meas[SCD30_HR] *= 10;
+
+	return 0;
+}
+
+static int scd30_wait_meas_irq(struct scd30_state *state)
+{
+	int ret, timeout;
+
+	reinit_completion(&state->meas_ready);
+	enable_irq(state->irq);
+	timeout = msecs_to_jiffies(state->meas_interval * (1000 + SCD30_EXTRA_TIMEOUT_PER_S));
+	ret = wait_for_completion_interruptible_timeout(&state->meas_ready, timeout);
+	if (ret > 0)
+		ret = 0;
+	else if (!ret)
+		ret = -ETIMEDOUT;
+
+	disable_irq(state->irq);
+
+	return ret;
+}
+
+static int scd30_wait_meas_poll(struct scd30_state *state)
+{
+	int timeout = state->meas_interval * SCD30_EXTRA_TIMEOUT_PER_S, tries = 5;
+
+	do {
+		int ret;
+		u16 val;
+
+		ret = scd30_command_read(state, CMD_MEAS_READY, &val);
+		if (ret)
+			return -EIO;
+
+		/* new measurement available */
+		if (val)
+			break;
+
+		msleep_interruptible(timeout);
+	} while (--tries);
+
+	return tries ? 0 : -ETIMEDOUT;
+}
+
+static int scd30_read_poll(struct scd30_state *state)
+{
+	int ret;
+
+	ret = scd30_wait_meas_poll(state);
+	if (ret)
+		return ret;
+
+	return scd30_read_meas(state);
+}
+
+static int scd30_read(struct scd30_state *state)
+{
+	if (state->irq > 0)
+		return scd30_wait_meas_irq(state);
+
+	return scd30_read_poll(state);
+}
+
+static int scd30_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
+			  int *val, int *val2, long mask)
+{
+	struct scd30_state *state = iio_priv(indio_dev);
+	int ret;
+	u16 tmp;
+
+	guard(mutex)(&state->lock);
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+	case IIO_CHAN_INFO_PROCESSED:
+		if (chan->output) {
+			*val = state->pressure_comp;
+			return IIO_VAL_INT;
+		}
+
+		if (!iio_device_claim_direct(indio_dev))
+			return -EBUSY;
+
+		ret = scd30_read(state);
+		if (ret) {
+			iio_device_release_direct(indio_dev);
+			return ret;
+		}
+
+		*val = state->meas[chan->address];
+		iio_device_release_direct(indio_dev);
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = 0;
+		*val2 = 1;
+		return IIO_VAL_INT_PLUS_MICRO;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		ret = scd30_command_read(state, CMD_MEAS_INTERVAL, &tmp);
+		if (ret)
+			return ret;
+
+		*val = 0;
+		*val2 = 1000000000 / tmp;
+		return IIO_VAL_INT_PLUS_NANO;
+	case IIO_CHAN_INFO_CALIBBIAS:
+		ret = scd30_command_read(state, CMD_TEMP_OFFSET, &tmp);
+		if (ret)
+			return ret;
+
+		*val = tmp;
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int scd30_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
+			   int val, int val2, long mask)
+{
+	struct scd30_state *state = iio_priv(indio_dev);
+	int ret;
+
+	guard(mutex)(&state->lock);
+	switch (mask) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		if (val || !val2)
+			return -EINVAL;
+
+		val = 1000000000 / val2;
+		if (val < SCD30_MEAS_INTERVAL_MIN_S || val > SCD30_MEAS_INTERVAL_MAX_S)
+			return -EINVAL;
+
+		ret = scd30_command_write(state, CMD_MEAS_INTERVAL, val);
+		if (ret)
+			return ret;
+
+		state->meas_interval = val;
+		return 0;
+	case IIO_CHAN_INFO_RAW:
+		switch (chan->type) {
+		case IIO_PRESSURE:
+			if (val < SCD30_PRESSURE_COMP_MIN_MBAR ||
+			    val > SCD30_PRESSURE_COMP_MAX_MBAR)
+				return -EINVAL;
+
+			ret = scd30_command_write(state, CMD_START_MEAS, val);
+			if (ret)
+				return ret;
+
+			state->pressure_comp = val;
+			return 0;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_CALIBBIAS:
+		if (val < 0 || val > SCD30_TEMP_OFFSET_MAX)
+			return -EINVAL;
+		/*
+		 * Manufacturer does not explicitly specify min/max sensible
+		 * values hence check is omitted for simplicity.
+		 */
+		return scd30_command_write(state, CMD_TEMP_OFFSET / 10, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int scd30_write_raw_get_fmt(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
+				   long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		return IIO_VAL_INT_PLUS_NANO;
+	case IIO_CHAN_INFO_RAW:
+	case IIO_CHAN_INFO_CALIBBIAS:
+		return IIO_VAL_INT;
+	}
+
+	return -EINVAL;
+}
+
+static const int scd30_pressure_raw_available[] = {
+	SCD30_PRESSURE_COMP_MIN_MBAR, 1, SCD30_PRESSURE_COMP_MAX_MBAR,
+};
+
+static const int scd30_temp_calibbias_available[] = {
+	0, 10, SCD30_TEMP_OFFSET_MAX,
+};
+
+static int scd30_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_RAW:
+		*vals = scd30_pressure_raw_available;
+		*type = IIO_VAL_INT;
+
+		return IIO_AVAIL_RANGE;
+	case IIO_CHAN_INFO_CALIBBIAS:
+		*vals = scd30_temp_calibbias_available;
+		*type = IIO_VAL_INT;
+
+		return IIO_AVAIL_RANGE;
+	}
+
+	return -EINVAL;
+}
+
+static ssize_t sampling_frequency_available_show(struct device *dev, struct device_attribute *attr,
+						 char *buf)
+{
+	int i = SCD30_MEAS_INTERVAL_MIN_S;
+	ssize_t len = 0;
+
+	do {
+		len += sysfs_emit_at(buf, len, "0.%09u ", 1000000000 / i);
+		/*
+		 * Not all values fit PAGE_SIZE buffer hence print every 6th
+		 * (each frequency differs by 6s in time domain from the
+		 * adjacent). Unlisted but valid ones are still accepted.
+		 */
+		i += 6;
+	} while (i <= SCD30_MEAS_INTERVAL_MAX_S);
+
+	buf[len - 1] = '\n';
+
+	return len;
+}
+
+static ssize_t calibration_auto_enable_show(struct device *dev, struct device_attribute *attr,
+					    char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct scd30_state *state = iio_priv(indio_dev);
+	int ret;
+	u16 val;
+
+	guard(mutex)(&state->lock);
+
+	ret = scd30_command_read(state, CMD_ASC, &val);
+	if (ret)
+		return ret;
+
+	return sysfs_emit(buf, "%d\n", val);
+}
+
+static ssize_t calibration_auto_enable_store(struct device *dev, struct device_attribute *attr,
+					     const char *buf, size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct scd30_state *state = iio_priv(indio_dev);
+	bool val;
+	int ret;
+
+	ret = kstrtobool(buf, &val);
+	if (ret)
+		return ret;
+
+	guard(mutex)(&state->lock);
+
+	ret = scd30_command_write(state, CMD_ASC, val);
+	if (ret)
+		return ret;
+
+	return len;
+}
+
+static ssize_t calibration_forced_value_show(struct device *dev, struct device_attribute *attr,
+					     char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct scd30_state *state = iio_priv(indio_dev);
+	int ret;
+	u16 val;
+
+	guard(mutex)(&state->lock);
+
+	ret = scd30_command_read(state, CMD_FRC, &val);
+	if (ret)
+		return ret;
+
+	return sysfs_emit(buf, "%d\n", val);
+}
+
+static ssize_t calibration_forced_value_store(struct device *dev, struct device_attribute *attr,
+					      const char *buf, size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct scd30_state *state = iio_priv(indio_dev);
+	int ret;
+	u16 val;
+
+	ret = kstrtou16(buf, 0, &val);
+	if (ret)
+		return ret;
+
+	if (val < SCD30_FRC_MIN_PPM || val > SCD30_FRC_MAX_PPM)
+		return -EINVAL;
+
+	guard(mutex)(&state->lock);
+
+	ret = scd30_command_write(state, CMD_FRC, val);
+	if (ret)
+		return ret;
+
+	return len;
+}
+
+static IIO_DEVICE_ATTR_RO(sampling_frequency_available, 0);
+static IIO_DEVICE_ATTR_RW(calibration_auto_enable, 0);
+static IIO_DEVICE_ATTR_RW(calibration_forced_value, 0);
+
+static struct attribute *scd30_attrs[] = {
+	&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
+	&iio_dev_attr_calibration_auto_enable.dev_attr.attr,
+	&iio_dev_attr_calibration_forced_value.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group scd30_attr_group = {
+	.attrs = scd30_attrs,
+};
+
+static const struct iio_info scd30_info = {
+	.attrs = &scd30_attr_group,
+	.read_raw = scd30_read_raw,
+	.write_raw = scd30_write_raw,
+	.write_raw_get_fmt = scd30_write_raw_get_fmt,
+	.read_avail = scd30_read_avail,
+};
+
+#define SCD30_CHAN_SCAN_TYPE(_sign, _realbits) .scan_type = { \
+	.sign = _sign, \
+	.realbits = _realbits, \
+	.storagebits = 32, \
+	.endianness = IIO_CPU, \
+}
+
+static const struct iio_chan_spec scd30_channels[] = {
+	{
+		/*
+		 * this channel is special in a sense we are pretending that
+		 * sensor is able to change measurement chamber pressure but in
+		 * fact we're just setting pressure compensation value
+		 */
+		.type = IIO_PRESSURE,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW),
+		.output = 1,
+		.scan_index = -1,
+	},
+	{
+		.type = IIO_CONCENTRATION,
+		.channel2 = IIO_MOD_CO2,
+		.address = SCD30_CONC,
+		.scan_index = SCD30_CONC,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+		.modified = 1,
+
+		SCD30_CHAN_SCAN_TYPE('u', 20),
+	},
+	{
+		.type = IIO_TEMP,
+		.address = SCD30_TEMP,
+		.scan_index = SCD30_TEMP,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+				      BIT(IIO_CHAN_INFO_CALIBBIAS),
+		.info_mask_separate_available = BIT(IIO_CHAN_INFO_CALIBBIAS),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+
+		SCD30_CHAN_SCAN_TYPE('s', 18),
+	},
+	{
+		.type = IIO_HUMIDITYRELATIVE,
+		.address = SCD30_HR,
+		.scan_index = SCD30_HR,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+
+		SCD30_CHAN_SCAN_TYPE('u', 17),
+	},
+	IIO_CHAN_SOFT_TIMESTAMP(3),
+};
+
+static int scd30_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct scd30_state *state  = iio_priv(indio_dev);
+	int ret;
+
+	ret = scd30_command_write(state, CMD_STOP_MEAS, 0);
+	if (ret)
+		return ret;
+
+	return regulator_disable(state->vdd);
+}
+
+static int scd30_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct scd30_state *state = iio_priv(indio_dev);
+	int ret;
+
+	ret = regulator_enable(state->vdd);
+	if (ret)
+		return ret;
+
+	return scd30_command_write(state, CMD_START_MEAS, state->pressure_comp);
+}
+
+EXPORT_NS_SIMPLE_DEV_PM_OPS(scd30_pm_ops, scd30_suspend, scd30_resume, IIO_SCD30);
+
+static void scd30_stop_meas(void *data)
+{
+	struct scd30_state *state = data;
+
+	scd30_command_write(state, CMD_STOP_MEAS, 0);
+}
+
+static void scd30_disable_regulator(void *data)
+{
+	struct scd30_state *state = data;
+
+	regulator_disable(state->vdd);
+}
+
+static irqreturn_t scd30_irq_handler(int irq, void *priv)
+{
+	struct iio_dev *indio_dev = priv;
+
+	if (iio_buffer_enabled(indio_dev)) {
+		iio_trigger_poll(indio_dev->trig);
+
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t scd30_irq_thread_handler(int irq, void *priv)
+{
+	struct iio_dev *indio_dev = priv;
+	struct scd30_state *state = iio_priv(indio_dev);
+	int ret;
+
+	ret = scd30_read_meas(state);
+	if (ret)
+		goto out;
+
+	complete_all(&state->meas_ready);
+out:
+	return IRQ_HANDLED;
+}
+
+static int scd30_trigger_handler_helper(struct iio_dev *indio_dev, int *scan_data,
+					size_t scan_data_size)
+{
+	struct scd30_state *state = iio_priv(indio_dev);
+	int ret;
+
+	guard(mutex)(&state->lock);
+
+	if (!iio_trigger_using_own(indio_dev))
+		ret = scd30_read_poll(state);
+	else
+		ret = scd30_read_meas(state);
+	memcpy(scan_data, state->meas, scan_data_size);
+
+	return ret;
+}
+
+static irqreturn_t scd30_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct {
+		int data[SCD30_MEAS_COUNT];
+		aligned_s64 ts;
+	} scan = { };
+	int ret;
+
+	ret = scd30_trigger_handler_helper(indio_dev, scan.data, sizeof(scan.data));
+	if (ret)
+		goto out;
+
+	iio_push_to_buffers_with_ts(indio_dev, &scan, sizeof(scan),
+				    iio_get_time_ns(indio_dev));
+out:
+	iio_trigger_notify_done(indio_dev->trig);
+	return IRQ_HANDLED;
+}
+
+static int scd30_set_trigger_state(struct iio_trigger *trig, bool state)
+{
+	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+	struct scd30_state *st = iio_priv(indio_dev);
+
+	if (state)
+		enable_irq(st->irq);
+	else
+		disable_irq(st->irq);
+
+	return 0;
+}
+
+static const struct iio_trigger_ops scd30_trigger_ops = {
+	.set_trigger_state = scd30_set_trigger_state,
+	.validate_device = iio_trigger_validate_own_device,
+};
+
+static int scd30_setup_trigger(struct iio_dev *indio_dev)
+{
+	struct scd30_state *state = iio_priv(indio_dev);
+	struct device *dev = indio_dev->dev.parent;
+	struct iio_trigger *trig;
+	int ret;
+
+	trig = devm_iio_trigger_alloc(dev, "%s-dev%d", indio_dev->name,
+				      iio_device_id(indio_dev));
+	if (!trig)
+		return -ENOMEM;
+
+	trig->ops = &scd30_trigger_ops;
+	iio_trigger_set_drvdata(trig, indio_dev);
+
+	ret = devm_iio_trigger_register(dev, trig);
+	if (ret)
+		return ret;
+
+	indio_dev->trig = iio_trigger_get(trig);
+
+	/*
+	 * Interrupt is enabled just before taking a fresh measurement
+	 * and disabled afterwards. This means we need to ensure it is not
+	 * enabled here to keep calls to enable/disable balanced.
+	 */
+	ret = devm_request_threaded_irq(dev, state->irq, scd30_irq_handler,
+					scd30_irq_thread_handler,
+					IRQF_TRIGGER_HIGH | IRQF_ONESHOT |
+					IRQF_NO_AUTOEN,
+					indio_dev->name, indio_dev);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+int scd30_probe(struct device *dev, int irq, const char *name, void *priv,
+		scd30_command_t command)
+{
+	static const unsigned long scd30_scan_masks[] = { 0x07, 0x00 };
+	struct scd30_state *state;
+	struct iio_dev *indio_dev;
+	int ret;
+	u16 val;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	state = iio_priv(indio_dev);
+	state->dev = dev;
+	state->priv = priv;
+	state->irq = irq;
+	state->pressure_comp = SCD30_PRESSURE_COMP_DEFAULT;
+	state->meas_interval = SCD30_MEAS_INTERVAL_DEFAULT;
+	state->command = command;
+
+	ret = devm_mutex_init(dev, &state->lock);
+	if (ret)
+		return ret;
+
+	init_completion(&state->meas_ready);
+
+	dev_set_drvdata(dev, indio_dev);
+
+	indio_dev->info = &scd30_info;
+	indio_dev->name = name;
+	indio_dev->channels = scd30_channels;
+	indio_dev->num_channels = ARRAY_SIZE(scd30_channels);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->available_scan_masks = scd30_scan_masks;
+
+	state->vdd = devm_regulator_get(dev, "vdd");
+	if (IS_ERR(state->vdd))
+		return dev_err_probe(dev, PTR_ERR(state->vdd), "failed to get regulator\n");
+
+	ret = regulator_enable(state->vdd);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(dev, scd30_disable_regulator, state);
+	if (ret)
+		return ret;
+
+	ret = scd30_reset(state);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to reset device\n");
+
+	if (state->irq > 0) {
+		ret = scd30_setup_trigger(indio_dev);
+		if (ret)
+			return dev_err_probe(dev, ret, "failed to setup trigger\n");
+	}
+
+	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL, scd30_trigger_handler, NULL);
+	if (ret)
+		return ret;
+
+	ret = scd30_command_read(state, CMD_FW_VERSION, &val);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to read firmware version\n");
+	dev_info(dev, "firmware version: %d.%d\n", val >> 8, (char)val);
+
+	ret = scd30_command_write(state, CMD_MEAS_INTERVAL, state->meas_interval);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to set measurement interval\n");
+
+	ret = scd30_command_write(state, CMD_START_MEAS, state->pressure_comp);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to start measurement\n");
+
+	ret = devm_add_action_or_reset(dev, scd30_stop_meas, state);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+EXPORT_SYMBOL_NS(scd30_probe, "IIO_SCD30");
+
+MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
+MODULE_DESCRIPTION("Sensirion SCD30 carbon dioxide sensor core driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/chemical/scd30_i2c.c b/drivers/iio/chemical/scd30_i2c.c
new file mode 100644
index 000000000..bcef1e473
--- /dev/null
+++ b/drivers/iio/chemical/scd30_i2c.c
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Sensirion SCD30 carbon dioxide sensor i2c driver
+ *
+ * Copyright (c) 2020 Tomasz Duszynski <tduszyns@gmail.com>
+ *
+ * I2C slave address: 0x61
+ */
+#include <linux/crc8.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/unaligned.h>
+
+#include "scd30.h"
+
+#define SCD30_I2C_MAX_BUF_SIZE 18
+#define SCD30_I2C_CRC8_POLYNOMIAL 0x31
+
+static const u16 scd30_i2c_cmd_lookup_tbl[] = {
+	[CMD_START_MEAS] = 0x0010,
+	[CMD_STOP_MEAS] = 0x0104,
+	[CMD_MEAS_INTERVAL] = 0x4600,
+	[CMD_MEAS_READY] = 0x0202,
+	[CMD_READ_MEAS] = 0x0300,
+	[CMD_ASC] = 0x5306,
+	[CMD_FRC] = 0x5204,
+	[CMD_TEMP_OFFSET] = 0x5403,
+	[CMD_FW_VERSION] = 0xd100,
+	[CMD_RESET] = 0xd304,
+};
+
+DECLARE_CRC8_TABLE(scd30_i2c_crc8_tbl);
+
+static int scd30_i2c_xfer(struct scd30_state *state, char *txbuf, int txsize,
+			  char *rxbuf, int rxsize)
+{
+	struct i2c_client *client = to_i2c_client(state->dev);
+	int ret;
+
+	/*
+	 * repeated start is not supported hence instead of sending two i2c
+	 * messages in a row we send one by one
+	 */
+	ret = i2c_master_send(client, txbuf, txsize);
+	if (ret < 0)
+		return ret;
+	if (ret != txsize)
+		return -EIO;
+
+	if (!rxbuf)
+		return 0;
+
+	ret = i2c_master_recv(client, rxbuf, rxsize);
+	if (ret < 0)
+		return ret;
+	if (ret != rxsize)
+		return -EIO;
+
+	return 0;
+}
+
+static int scd30_i2c_command(struct scd30_state *state, enum scd30_cmd cmd, u16 arg,
+			     void *response, int size)
+{
+	char buf[SCD30_I2C_MAX_BUF_SIZE];
+	char *rsp = response;
+	int i, ret;
+	char crc;
+
+	if (!response && size != 0)
+		return -EINVAL;
+
+	put_unaligned_be16(scd30_i2c_cmd_lookup_tbl[cmd], buf);
+	i = 2;
+
+	if (rsp) {
+		/* each two bytes are followed by a crc8 */
+		size += size / 2;
+	} else {
+		put_unaligned_be16(arg, buf + i);
+		crc = crc8(scd30_i2c_crc8_tbl, buf + i, 2, CRC8_INIT_VALUE);
+		i += 2;
+		buf[i] = crc;
+		i += 1;
+
+		/* commands below don't take an argument */
+		if ((cmd == CMD_STOP_MEAS) || (cmd == CMD_RESET))
+			i -= 3;
+	}
+
+	ret = scd30_i2c_xfer(state, buf, i, buf, size);
+	if (ret)
+		return ret;
+
+	/* validate received data and strip off crc bytes */
+	for (i = 0; i < size; i += 3) {
+		crc = crc8(scd30_i2c_crc8_tbl, buf + i, 2, CRC8_INIT_VALUE);
+		if (crc != buf[i + 2]) {
+			dev_err(state->dev, "data integrity check failed\n");
+			return -EIO;
+		}
+
+		*rsp++ = buf[i];
+		*rsp++ = buf[i + 1];
+	}
+
+	return 0;
+}
+
+static int scd30_i2c_probe(struct i2c_client *client)
+{
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+		return -EOPNOTSUPP;
+
+	crc8_populate_msb(scd30_i2c_crc8_tbl, SCD30_I2C_CRC8_POLYNOMIAL);
+
+	return scd30_probe(&client->dev, client->irq, client->name, NULL, scd30_i2c_command);
+}
+
+static const struct of_device_id scd30_i2c_of_match[] = {
+	{ .compatible = "sensirion,scd30" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, scd30_i2c_of_match);
+
+static struct i2c_driver scd30_i2c_driver = {
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.of_match_table = scd30_i2c_of_match,
+		.pm = pm_sleep_ptr(&scd30_pm_ops),
+	},
+	.probe = scd30_i2c_probe,
+};
+module_i2c_driver(scd30_i2c_driver);
+
+MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
+MODULE_DESCRIPTION("Sensirion SCD30 carbon dioxide sensor i2c driver");
+MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS("IIO_SCD30");
diff --git a/drivers/iio/chemical/scd30_serial.c b/drivers/iio/chemical/scd30_serial.c
new file mode 100644
index 000000000..31b0fc957
--- /dev/null
+++ b/drivers/iio/chemical/scd30_serial.c
@@ -0,0 +1,263 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Sensirion SCD30 carbon dioxide sensor serial driver
+ *
+ * Copyright (c) 2020 Tomasz Duszynski <tduszyns@gmail.com>
+ */
+#include <linux/crc16.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/iio/iio.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/serdev.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/unaligned.h>
+
+#include "scd30.h"
+
+#define SCD30_SERDEV_ADDR 0x61
+#define SCD30_SERDEV_WRITE 0x06
+#define SCD30_SERDEV_READ 0x03
+#define SCD30_SERDEV_MAX_BUF_SIZE 17
+#define SCD30_SERDEV_RX_HEADER_SIZE 3
+#define SCD30_SERDEV_CRC_SIZE 2
+#define SCD30_SERDEV_TIMEOUT msecs_to_jiffies(200)
+
+struct scd30_serdev_priv {
+	struct completion meas_ready;
+	char *buf;
+	int num_expected;
+	int num;
+};
+
+static u16 scd30_serdev_cmd_lookup_tbl[] = {
+	[CMD_START_MEAS] = 0x0036,
+	[CMD_STOP_MEAS] = 0x0037,
+	[CMD_MEAS_INTERVAL] = 0x0025,
+	[CMD_MEAS_READY] = 0x0027,
+	[CMD_READ_MEAS] = 0x0028,
+	[CMD_ASC] = 0x003a,
+	[CMD_FRC] = 0x0039,
+	[CMD_TEMP_OFFSET] = 0x003b,
+	[CMD_FW_VERSION] = 0x0020,
+	[CMD_RESET] = 0x0034,
+};
+
+static u16 scd30_serdev_calc_crc(const char *buf, int size)
+{
+	return crc16(0xffff, buf, size);
+}
+
+static int scd30_serdev_xfer(struct scd30_state *state, char *txbuf, int txsize,
+			     char *rxbuf, int rxsize)
+{
+	struct serdev_device *serdev = to_serdev_device(state->dev);
+	struct scd30_serdev_priv *priv = state->priv;
+	int ret;
+
+	priv->buf = rxbuf;
+	priv->num_expected = rxsize;
+	priv->num = 0;
+
+	ret = serdev_device_write(serdev, txbuf, txsize, SCD30_SERDEV_TIMEOUT);
+	if (ret < 0)
+		return ret;
+	if (ret != txsize)
+		return -EIO;
+
+	ret = wait_for_completion_interruptible_timeout(&priv->meas_ready, SCD30_SERDEV_TIMEOUT);
+	if (ret < 0)
+		return ret;
+	if (!ret)
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
+static int scd30_serdev_command(struct scd30_state *state, enum scd30_cmd cmd, u16 arg,
+				void *response, int size)
+{
+	/*
+	 * Communication over serial line is based on modbus protocol (or rather
+	 * its variation called modbus over serial to be precise). Upon
+	 * receiving a request device should reply with response.
+	 *
+	 * Frame below represents a request message. Each field takes
+	 * exactly one byte.
+	 *
+	 * +------+------+-----+-----+-------+-------+-----+-----+
+	 * | dev  | op   | reg | reg | byte1 | byte0 | crc | crc |
+	 * | addr | code | msb | lsb |       |       | lsb | msb |
+	 * +------+------+-----+-----+-------+-------+-----+-----+
+	 *
+	 * The message device replies with depends on the 'op code' field from
+	 * the request. In case it was set to SCD30_SERDEV_WRITE sensor should
+	 * reply with unchanged request. Otherwise 'op code' was set to
+	 * SCD30_SERDEV_READ and response looks like the one below. As with
+	 * request, each field takes one byte.
+	 *
+	 * +------+------+--------+-------+-----+-------+-----+-----+
+	 * | dev  | op   | num of | byte0 | ... | byteN | crc | crc |
+	 * | addr | code | bytes  |       |     |       | lsb | msb |
+	 * +------+------+--------+-------+-----+-------+-----+-----+
+	 */
+	char txbuf[SCD30_SERDEV_MAX_BUF_SIZE] = { SCD30_SERDEV_ADDR },
+	     rxbuf[SCD30_SERDEV_MAX_BUF_SIZE];
+	int ret, rxsize, txsize = 2;
+	char *rsp = response;
+	u16 crc;
+
+	put_unaligned_be16(scd30_serdev_cmd_lookup_tbl[cmd], txbuf + txsize);
+	txsize += 2;
+
+	if (rsp) {
+		txbuf[1] = SCD30_SERDEV_READ;
+		if (cmd == CMD_READ_MEAS)
+			/* number of u16 words to read */
+			put_unaligned_be16(size / 2, txbuf + txsize);
+		else
+			put_unaligned_be16(0x0001, txbuf + txsize);
+		txsize += 2;
+		crc = scd30_serdev_calc_crc(txbuf, txsize);
+		put_unaligned_le16(crc, txbuf + txsize);
+		txsize += 2;
+		rxsize = SCD30_SERDEV_RX_HEADER_SIZE + size + SCD30_SERDEV_CRC_SIZE;
+	} else {
+		if ((cmd == CMD_STOP_MEAS) || (cmd == CMD_RESET))
+			arg = 0x0001;
+
+		txbuf[1] = SCD30_SERDEV_WRITE;
+		put_unaligned_be16(arg, txbuf + txsize);
+		txsize += 2;
+		crc = scd30_serdev_calc_crc(txbuf, txsize);
+		put_unaligned_le16(crc, txbuf + txsize);
+		txsize += 2;
+		rxsize = txsize;
+	}
+
+	ret = scd30_serdev_xfer(state, txbuf, txsize, rxbuf, rxsize);
+	if (ret)
+		return ret;
+
+	switch (txbuf[1]) {
+	case SCD30_SERDEV_WRITE:
+		if (memcmp(txbuf, rxbuf, txsize)) {
+			dev_err(state->dev, "wrong message received\n");
+			return -EIO;
+		}
+		break;
+	case SCD30_SERDEV_READ:
+		if (rxbuf[2] != (rxsize - SCD30_SERDEV_RX_HEADER_SIZE - SCD30_SERDEV_CRC_SIZE)) {
+			dev_err(state->dev, "received data size does not match header\n");
+			return -EIO;
+		}
+
+		rxsize -= SCD30_SERDEV_CRC_SIZE;
+		crc = get_unaligned_le16(rxbuf + rxsize);
+		if (crc != scd30_serdev_calc_crc(rxbuf, rxsize)) {
+			dev_err(state->dev, "data integrity check failed\n");
+			return -EIO;
+		}
+
+		rxsize -= SCD30_SERDEV_RX_HEADER_SIZE;
+		memcpy(rsp, rxbuf + SCD30_SERDEV_RX_HEADER_SIZE, rxsize);
+		break;
+	default:
+		dev_err(state->dev, "received unknown op code\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static size_t scd30_serdev_receive_buf(struct serdev_device *serdev,
+				       const u8 *buf, size_t size)
+{
+	struct iio_dev *indio_dev = serdev_device_get_drvdata(serdev);
+	struct scd30_serdev_priv *priv;
+	struct scd30_state *state;
+	size_t num;
+
+	if (!indio_dev)
+		return 0;
+
+	state = iio_priv(indio_dev);
+	priv = state->priv;
+
+	/* just in case sensor puts some unexpected bytes on the bus */
+	if (!priv->buf)
+		return 0;
+
+	if (priv->num + size >= priv->num_expected)
+		num = priv->num_expected - priv->num;
+	else
+		num = size;
+
+	memcpy(priv->buf + priv->num, buf, num);
+	priv->num += num;
+
+	if (priv->num == priv->num_expected) {
+		priv->buf = NULL;
+		complete(&priv->meas_ready);
+	}
+
+	return num;
+}
+
+static const struct serdev_device_ops scd30_serdev_ops = {
+	.receive_buf = scd30_serdev_receive_buf,
+	.write_wakeup = serdev_device_write_wakeup,
+};
+
+static int scd30_serdev_probe(struct serdev_device *serdev)
+{
+	struct device *dev = &serdev->dev;
+	struct scd30_serdev_priv *priv;
+	int irq, ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	init_completion(&priv->meas_ready);
+	serdev_device_set_client_ops(serdev, &scd30_serdev_ops);
+
+	ret = devm_serdev_device_open(dev, serdev);
+	if (ret)
+		return ret;
+
+	serdev_device_set_baudrate(serdev, 19200);
+	serdev_device_set_flow_control(serdev, false);
+
+	ret = serdev_device_set_parity(serdev, SERDEV_PARITY_NONE);
+	if (ret)
+		return ret;
+
+	irq = fwnode_irq_get(dev_fwnode(dev), 0);
+
+	return scd30_probe(dev, irq, KBUILD_MODNAME, priv, scd30_serdev_command);
+}
+
+static const struct of_device_id scd30_serdev_of_match[] = {
+	{ .compatible = "sensirion,scd30" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, scd30_serdev_of_match);
+
+static struct serdev_device_driver scd30_serdev_driver = {
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.of_match_table = scd30_serdev_of_match,
+		.pm = pm_sleep_ptr(&scd30_pm_ops),
+	},
+	.probe = scd30_serdev_probe,
+};
+module_serdev_device_driver(scd30_serdev_driver);
+
+MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
+MODULE_DESCRIPTION("Sensirion SCD30 carbon dioxide sensor serial driver");
+MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS("IIO_SCD30");
diff --git a/drivers/iio/chemical/scd4x.c b/drivers/iio/chemical/scd4x.c
new file mode 100644
index 000000000..23a326fb6
--- /dev/null
+++ b/drivers/iio/chemical/scd4x.c
@@ -0,0 +1,768 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Sensirion SCD4X carbon dioxide sensor i2c driver
+ *
+ * Copyright (C) 2021 Protonic Holland
+ * Author: Roan van Dijk <roan@protonic.nl>
+ *
+ * I2C slave address: 0x62
+ *
+ * Datasheets:
+ * https://www.sensirion.com/file/datasheet_scd4x
+ */
+
+#include <linux/unaligned.h>
+#include <linux/crc8.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/iio/buffer.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>
+#include <linux/iio/types.h>
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/string.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+
+#define SCD4X_CRC8_POLYNOMIAL 0x31
+#define SCD4X_TIMEOUT_ERR 1000
+#define SCD4X_READ_BUF_SIZE 9
+#define SCD4X_COMMAND_BUF_SIZE 2
+#define SCD4X_WRITE_BUF_SIZE 5
+#define SCD4X_FRC_MIN_PPM 0
+#define SCD4X_FRC_MAX_PPM 2000
+#define SCD4X_PRESSURE_COMP_MIN_MBAR 700
+#define SCD4X_PRESSURE_COMP_MAX_MBAR 1200
+#define SCD4X_READY_MASK 0x01
+
+/*Commands SCD4X*/
+enum scd4x_cmd {
+	CMD_START_MEAS          = 0x21b1,
+	CMD_READ_MEAS           = 0xec05,
+	CMD_STOP_MEAS           = 0x3f86,
+	CMD_SET_TEMP_OFFSET     = 0x241d,
+	CMD_GET_TEMP_OFFSET     = 0x2318,
+	CMD_SET_AMB_PRESSURE	= 0xe000,
+	CMD_GET_AMB_PRESSURE	= 0xe000,
+	CMD_FRC                 = 0x362f,
+	CMD_SET_ASC             = 0x2416,
+	CMD_GET_ASC             = 0x2313,
+	CMD_GET_DATA_READY      = 0xe4b8,
+};
+
+enum scd4x_channel_idx {
+	SCD4X_CO2,
+	SCD4X_TEMP,
+	SCD4X_HR,
+	/* kernel timestamp, at the end of buffer */
+	SCD4X_TS,
+};
+
+struct scd4x_state {
+	struct i2c_client *client;
+	/* maintain access to device, to prevent concurrent reads/writes */
+	struct mutex lock;
+	struct regulator *vdd;
+};
+
+DECLARE_CRC8_TABLE(scd4x_crc8_table);
+
+static int scd4x_i2c_xfer(struct scd4x_state *state, char *txbuf, int txsize,
+				char *rxbuf, int rxsize)
+{
+	struct i2c_client *client = state->client;
+	int ret;
+
+	ret = i2c_master_send(client, txbuf, txsize);
+
+	if (ret < 0)
+		return ret;
+	if (ret != txsize)
+		return -EIO;
+
+	if (rxsize == 0)
+		return 0;
+
+	ret = i2c_master_recv(client, rxbuf, rxsize);
+	if (ret < 0)
+		return ret;
+	if (ret != rxsize)
+		return -EIO;
+
+	return 0;
+}
+
+static int scd4x_send_command(struct scd4x_state *state, enum scd4x_cmd cmd)
+{
+	char buf[SCD4X_COMMAND_BUF_SIZE];
+	int ret;
+
+	/*
+	 * Measurement needs to be stopped before sending commands.
+	 * Except stop and start command.
+	 */
+	if ((cmd != CMD_STOP_MEAS) && (cmd != CMD_START_MEAS)) {
+
+		ret = scd4x_send_command(state, CMD_STOP_MEAS);
+		if (ret)
+			return ret;
+
+		/* execution time for stopping measurement */
+		msleep_interruptible(500);
+	}
+
+	put_unaligned_be16(cmd, buf);
+	ret = scd4x_i2c_xfer(state, buf, 2, buf, 0);
+	if (ret)
+		return ret;
+
+	if ((cmd != CMD_STOP_MEAS) && (cmd != CMD_START_MEAS)) {
+		ret = scd4x_send_command(state, CMD_START_MEAS);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int scd4x_read(struct scd4x_state *state, enum scd4x_cmd cmd,
+			void *response, int response_sz)
+{
+	struct i2c_client *client = state->client;
+	char buf[SCD4X_READ_BUF_SIZE];
+	char *rsp = response;
+	int i, ret;
+	char crc;
+
+	/*
+	 * Measurement needs to be stopped before sending commands.
+	 * Except for reading measurement and data ready command.
+	 */
+	if ((cmd != CMD_GET_DATA_READY) && (cmd != CMD_READ_MEAS) &&
+	    (cmd != CMD_GET_AMB_PRESSURE)) {
+		ret = scd4x_send_command(state, CMD_STOP_MEAS);
+		if (ret)
+			return ret;
+
+		/* execution time for stopping measurement */
+		msleep_interruptible(500);
+	}
+
+	/* CRC byte for every 2 bytes of data */
+	response_sz += response_sz / 2;
+
+	put_unaligned_be16(cmd, buf);
+	ret = scd4x_i2c_xfer(state, buf, 2, buf, response_sz);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < response_sz; i += 3) {
+		crc = crc8(scd4x_crc8_table, buf + i, 2, CRC8_INIT_VALUE);
+		if (crc != buf[i + 2]) {
+			dev_err(&client->dev, "CRC error\n");
+			return -EIO;
+		}
+
+		*rsp++ = buf[i];
+		*rsp++ = buf[i + 1];
+	}
+
+	/* start measurement */
+	if ((cmd != CMD_GET_DATA_READY) && (cmd != CMD_READ_MEAS) &&
+	    (cmd != CMD_GET_AMB_PRESSURE)) {
+		ret = scd4x_send_command(state, CMD_START_MEAS);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int scd4x_write(struct scd4x_state *state, enum scd4x_cmd cmd, uint16_t arg)
+{
+	char buf[SCD4X_WRITE_BUF_SIZE];
+	int ret;
+	char crc;
+
+	put_unaligned_be16(cmd, buf);
+	put_unaligned_be16(arg, buf + 2);
+
+	crc = crc8(scd4x_crc8_table, buf + 2, 2, CRC8_INIT_VALUE);
+	buf[4] = crc;
+
+	/* measurement needs to be stopped before sending commands */
+	if (cmd != CMD_SET_AMB_PRESSURE) {
+		ret = scd4x_send_command(state, CMD_STOP_MEAS);
+		if (ret)
+			return ret;
+	}
+
+	/* execution time */
+	msleep_interruptible(500);
+
+	ret = scd4x_i2c_xfer(state, buf, SCD4X_WRITE_BUF_SIZE, buf, 0);
+	if (ret)
+		return ret;
+
+	/* start measurement, except for forced calibration command */
+	if ((cmd != CMD_FRC) && (cmd != CMD_SET_AMB_PRESSURE)) {
+		ret = scd4x_send_command(state, CMD_START_MEAS);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int scd4x_write_and_fetch(struct scd4x_state *state, enum scd4x_cmd cmd,
+				uint16_t arg, void *response, int response_sz)
+{
+	struct i2c_client *client = state->client;
+	char buf[SCD4X_READ_BUF_SIZE];
+	char *rsp = response;
+	int i, ret;
+	char crc;
+
+	ret = scd4x_write(state, CMD_FRC, arg);
+	if (ret)
+		goto err;
+
+	/* execution time */
+	msleep_interruptible(400);
+
+	/* CRC byte for every 2 bytes of data */
+	response_sz += response_sz / 2;
+
+	ret = i2c_master_recv(client, buf, response_sz);
+	if (ret < 0)
+		goto err;
+	if (ret != response_sz) {
+		ret = -EIO;
+		goto err;
+	}
+
+	for (i = 0; i < response_sz; i += 3) {
+		crc = crc8(scd4x_crc8_table, buf + i, 2, CRC8_INIT_VALUE);
+		if (crc != buf[i + 2]) {
+			dev_err(&client->dev, "CRC error\n");
+			ret = -EIO;
+			goto err;
+		}
+
+		*rsp++ = buf[i];
+		*rsp++ = buf[i + 1];
+	}
+
+	return scd4x_send_command(state, CMD_START_MEAS);
+
+err:
+	/*
+	 * on error try to start the measurement,
+	 * puts sensor back into continuous measurement
+	 */
+	scd4x_send_command(state, CMD_START_MEAS);
+
+	return ret;
+}
+
+static int scd4x_read_meas(struct scd4x_state *state, uint16_t *meas)
+{
+	int i, ret;
+	__be16 buf[3];
+
+	ret = scd4x_read(state, CMD_READ_MEAS, buf, sizeof(buf));
+	if (ret)
+		return ret;
+
+	for (i = 0; i < ARRAY_SIZE(buf); i++)
+		meas[i] = be16_to_cpu(buf[i]);
+
+	return 0;
+}
+
+static int scd4x_wait_meas_poll(struct scd4x_state *state)
+{
+	struct i2c_client *client = state->client;
+	int tries = 6;
+	int ret;
+
+	do {
+		__be16 bval;
+		uint16_t val;
+
+		ret = scd4x_read(state, CMD_GET_DATA_READY, &bval, sizeof(bval));
+		if (ret)
+			return -EIO;
+		val = be16_to_cpu(bval);
+
+		/* new measurement available */
+		if (val & 0x7FF)
+			return 0;
+
+		msleep_interruptible(1000);
+	} while (--tries);
+
+	/* try to start sensor on timeout */
+	ret = scd4x_send_command(state, CMD_START_MEAS);
+	if (ret)
+		dev_err(&client->dev, "failed to start measurement: %d\n", ret);
+
+	return -ETIMEDOUT;
+}
+
+static int scd4x_read_poll(struct scd4x_state *state, uint16_t *buf)
+{
+	int ret;
+
+	ret = scd4x_wait_meas_poll(state);
+	if (ret)
+		return ret;
+
+	return scd4x_read_meas(state, buf);
+}
+
+static int scd4x_read_channel(struct scd4x_state *state, int chan)
+{
+	int ret;
+	uint16_t buf[3];
+
+	ret = scd4x_read_poll(state, buf);
+	if (ret)
+		return ret;
+
+	return buf[chan];
+}
+
+static int scd4x_read_raw(struct iio_dev *indio_dev,
+			struct iio_chan_spec const *chan, int *val,
+			int *val2, long mask)
+{
+	struct scd4x_state *state = iio_priv(indio_dev);
+	int ret;
+	__be16 tmp;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		if (chan->output) {
+			mutex_lock(&state->lock);
+			ret = scd4x_read(state, CMD_GET_AMB_PRESSURE, &tmp, sizeof(tmp));
+			mutex_unlock(&state->lock);
+
+			if (ret)
+				return ret;
+
+			*val = be16_to_cpu(tmp);
+			return IIO_VAL_INT;
+		}
+
+		if (!iio_device_claim_direct(indio_dev))
+			return -EBUSY;
+
+		mutex_lock(&state->lock);
+		ret = scd4x_read_channel(state, chan->address);
+		mutex_unlock(&state->lock);
+
+		iio_device_release_direct(indio_dev);
+		if (ret < 0)
+			return ret;
+
+		*val = ret;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		if (chan->type == IIO_CONCENTRATION) {
+			*val = 0;
+			*val2 = 100;
+			return IIO_VAL_INT_PLUS_MICRO;
+		} else if (chan->type == IIO_TEMP) {
+			*val = 175000;
+			*val2 = 65536;
+			return IIO_VAL_FRACTIONAL;
+		} else if (chan->type == IIO_HUMIDITYRELATIVE) {
+			*val = 100000;
+			*val2 = 65536;
+			return IIO_VAL_FRACTIONAL;
+		}
+		return -EINVAL;
+	case IIO_CHAN_INFO_OFFSET:
+		*val = -16852;
+		*val2 = 114286;
+		return IIO_VAL_INT_PLUS_MICRO;
+	case IIO_CHAN_INFO_CALIBBIAS:
+		mutex_lock(&state->lock);
+		ret = scd4x_read(state, CMD_GET_TEMP_OFFSET, &tmp, sizeof(tmp));
+		mutex_unlock(&state->lock);
+		if (ret)
+			return ret;
+
+		*val = be16_to_cpu(tmp);
+
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const int scd4x_pressure_calibbias_available[] = {
+	SCD4X_PRESSURE_COMP_MIN_MBAR, 1, SCD4X_PRESSURE_COMP_MAX_MBAR,
+};
+
+static int scd4x_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_RAW:
+		*vals = scd4x_pressure_calibbias_available;
+		*type = IIO_VAL_INT;
+
+		return IIO_AVAIL_RANGE;
+	}
+
+	return -EINVAL;
+}
+
+
+static int scd4x_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
+				int val, int val2, long mask)
+{
+	struct scd4x_state *state = iio_priv(indio_dev);
+	int ret = 0;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_CALIBBIAS:
+		mutex_lock(&state->lock);
+		ret = scd4x_write(state, CMD_SET_TEMP_OFFSET, val);
+		mutex_unlock(&state->lock);
+
+		return ret;
+	case IIO_CHAN_INFO_RAW:
+		switch (chan->type) {
+		case IIO_PRESSURE:
+			if (val < SCD4X_PRESSURE_COMP_MIN_MBAR ||
+			    val > SCD4X_PRESSURE_COMP_MAX_MBAR)
+				return -EINVAL;
+
+			mutex_lock(&state->lock);
+			ret = scd4x_write(state, CMD_SET_AMB_PRESSURE, val);
+			mutex_unlock(&state->lock);
+
+			return ret;
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+}
+
+static ssize_t calibration_auto_enable_show(struct device *dev,
+			struct device_attribute *attr, char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct scd4x_state *state = iio_priv(indio_dev);
+	int ret;
+	__be16 bval;
+	u16 val;
+
+	mutex_lock(&state->lock);
+	ret = scd4x_read(state, CMD_GET_ASC, &bval, sizeof(bval));
+	mutex_unlock(&state->lock);
+	if (ret) {
+		dev_err(dev, "failed to read automatic calibration");
+		return ret;
+	}
+
+	val = (be16_to_cpu(bval) & SCD4X_READY_MASK) ? 1 : 0;
+
+	return sysfs_emit(buf, "%d\n", val);
+}
+
+static ssize_t calibration_auto_enable_store(struct device *dev,
+					struct device_attribute *attr,
+					const char *buf, size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct scd4x_state *state = iio_priv(indio_dev);
+	bool val;
+	int ret;
+	uint16_t value;
+
+	ret = kstrtobool(buf, &val);
+	if (ret)
+		return ret;
+
+	value = val;
+
+	mutex_lock(&state->lock);
+	ret = scd4x_write(state, CMD_SET_ASC, value);
+	mutex_unlock(&state->lock);
+	if (ret)
+		dev_err(dev, "failed to set automatic calibration");
+
+	return ret ?: len;
+}
+
+static ssize_t calibration_forced_value_store(struct device *dev,
+					struct device_attribute *attr,
+					const char *buf, size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct scd4x_state *state = iio_priv(indio_dev);
+	uint16_t val, arg;
+	int ret;
+
+	ret = kstrtou16(buf, 0, &arg);
+	if (ret)
+		return ret;
+
+	if (arg < SCD4X_FRC_MIN_PPM || arg > SCD4X_FRC_MAX_PPM)
+		return -EINVAL;
+
+	mutex_lock(&state->lock);
+	ret = scd4x_write_and_fetch(state, CMD_FRC, arg, &val, sizeof(val));
+	mutex_unlock(&state->lock);
+
+	if (ret)
+		return ret;
+
+	if (val == 0xff) {
+		dev_err(dev, "forced calibration has failed");
+		return -EINVAL;
+	}
+
+	return len;
+}
+
+static IIO_DEVICE_ATTR_RW(calibration_auto_enable, 0);
+static IIO_DEVICE_ATTR_WO(calibration_forced_value, 0);
+
+static IIO_CONST_ATTR(calibration_forced_value_available,
+	       __stringify([SCD4X_FRC_MIN_PPM 1 SCD4X_FRC_MAX_PPM]));
+
+static struct attribute *scd4x_attrs[] = {
+	&iio_dev_attr_calibration_auto_enable.dev_attr.attr,
+	&iio_dev_attr_calibration_forced_value.dev_attr.attr,
+	&iio_const_attr_calibration_forced_value_available.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group scd4x_attr_group = {
+	.attrs = scd4x_attrs,
+};
+
+static const struct iio_info scd4x_info = {
+	.attrs = &scd4x_attr_group,
+	.read_raw = scd4x_read_raw,
+	.write_raw = scd4x_write_raw,
+	.read_avail = scd4x_read_avail,
+};
+
+static const struct iio_chan_spec scd4x_channels[] = {
+	{
+		/*
+		 * this channel is special in a sense we are pretending that
+		 * sensor is able to change measurement chamber pressure but in
+		 * fact we're just setting pressure compensation value
+		 */
+		.type = IIO_PRESSURE,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW),
+		.output = 1,
+		.scan_index = -1,
+	},
+	{
+		.type = IIO_CONCENTRATION,
+		.channel2 = IIO_MOD_CO2,
+		.modified = 1,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+					BIT(IIO_CHAN_INFO_SCALE),
+		.address = SCD4X_CO2,
+		.scan_index = SCD4X_CO2,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_CPU,
+		},
+	},
+	{
+		.type = IIO_TEMP,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+					BIT(IIO_CHAN_INFO_SCALE) |
+					BIT(IIO_CHAN_INFO_OFFSET) |
+					BIT(IIO_CHAN_INFO_CALIBBIAS),
+		.address = SCD4X_TEMP,
+		.scan_index = SCD4X_TEMP,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_CPU,
+		},
+	},
+	{
+		.type = IIO_HUMIDITYRELATIVE,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+					BIT(IIO_CHAN_INFO_SCALE),
+		.address = SCD4X_HR,
+		.scan_index = SCD4X_HR,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_CPU,
+		},
+	},
+	IIO_CHAN_SOFT_TIMESTAMP(SCD4X_TS),
+};
+
+static int scd4x_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct scd4x_state *state  = iio_priv(indio_dev);
+	int ret;
+
+	ret = scd4x_send_command(state, CMD_STOP_MEAS);
+	if (ret)
+		return ret;
+
+	return regulator_disable(state->vdd);
+}
+
+static int scd4x_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct scd4x_state *state = iio_priv(indio_dev);
+	int ret;
+
+	ret = regulator_enable(state->vdd);
+	if (ret)
+		return ret;
+
+	return scd4x_send_command(state, CMD_START_MEAS);
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(scd4x_pm_ops, scd4x_suspend, scd4x_resume);
+
+static void scd4x_stop_meas(void *state)
+{
+	scd4x_send_command(state, CMD_STOP_MEAS);
+}
+
+static void scd4x_disable_regulator(void *data)
+{
+	struct scd4x_state *state = data;
+
+	regulator_disable(state->vdd);
+}
+
+static irqreturn_t scd4x_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct scd4x_state *state = iio_priv(indio_dev);
+	struct {
+		uint16_t data[3];
+		aligned_s64 ts;
+	} scan = { };
+	int ret;
+
+	mutex_lock(&state->lock);
+	ret = scd4x_read_poll(state, scan.data);
+	mutex_unlock(&state->lock);
+	if (ret)
+		goto out;
+
+	iio_push_to_buffers_with_ts(indio_dev, &scan, sizeof(scan),
+				    iio_get_time_ns(indio_dev));
+out:
+	iio_trigger_notify_done(indio_dev->trig);
+	return IRQ_HANDLED;
+}
+
+static int scd4x_probe(struct i2c_client *client)
+{
+	static const unsigned long scd4x_scan_masks[] = { 0x07, 0x00 };
+	struct device *dev = &client->dev;
+	struct iio_dev *indio_dev;
+	struct scd4x_state *state;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	state = iio_priv(indio_dev);
+	mutex_init(&state->lock);
+	state->client = client;
+	crc8_populate_msb(scd4x_crc8_table, SCD4X_CRC8_POLYNOMIAL);
+
+	indio_dev->info = &scd4x_info;
+	indio_dev->name = client->name;
+	indio_dev->channels = scd4x_channels;
+	indio_dev->num_channels = ARRAY_SIZE(scd4x_channels);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->available_scan_masks = scd4x_scan_masks;
+
+	state->vdd = devm_regulator_get(dev, "vdd");
+	if (IS_ERR(state->vdd))
+		return dev_err_probe(dev, PTR_ERR(state->vdd), "failed to get regulator\n");
+
+	ret = regulator_enable(state->vdd);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(dev, scd4x_disable_regulator, state);
+	if (ret)
+		return ret;
+
+	ret = scd4x_send_command(state, CMD_STOP_MEAS);
+	if (ret) {
+		dev_err(dev, "failed to stop measurement: %d\n", ret);
+		return ret;
+	}
+
+	/* execution time */
+	msleep_interruptible(500);
+
+	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL, scd4x_trigger_handler, NULL);
+	if (ret)
+		return ret;
+
+	ret = scd4x_send_command(state, CMD_START_MEAS);
+	if (ret) {
+		dev_err(dev, "failed to start measurement: %d\n", ret);
+		return ret;
+	}
+
+	ret = devm_add_action_or_reset(dev, scd4x_stop_meas, state);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct of_device_id scd4x_dt_ids[] = {
+	{ .compatible = "sensirion,scd40" },
+	{ .compatible = "sensirion,scd41" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, scd4x_dt_ids);
+
+static struct i2c_driver scd4x_i2c_driver = {
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.of_match_table = scd4x_dt_ids,
+		.pm = pm_sleep_ptr(&scd4x_pm_ops),
+	},
+	.probe = scd4x_probe,
+};
+module_i2c_driver(scd4x_i2c_driver);
+
+MODULE_AUTHOR("Roan van Dijk <roan@protonic.nl>");
+MODULE_DESCRIPTION("Sensirion SCD4X carbon dioxide sensor core driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/chemical/sen0322.c b/drivers/iio/chemical/sen0322.c
new file mode 100644
index 000000000..96c6fc120
--- /dev/null
+++ b/drivers/iio/chemical/sen0322.c
@@ -0,0 +1,161 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for the DFRobot SEN0322 oxygen sensor.
+ *
+ * Datasheet:
+ *	https://wiki.dfrobot.com/Gravity_I2C_Oxygen_Sensor_SKU_SEN0322
+ *
+ * Possible I2C slave addresses:
+ *	0x70
+ *	0x71
+ *	0x72
+ *	0x73
+ *
+ * Copyright (C) 2025 Tóth János <gomba007@gmail.com>
+ */
+
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+
+#include <linux/iio/iio.h>
+
+#define SEN0322_REG_DATA	0x03
+#define SEN0322_REG_COEFF	0x0A
+
+struct sen0322 {
+	struct regmap	*regmap;
+};
+
+static int sen0322_read_data(struct sen0322 *sen0322)
+{
+	u8 data[3] = { };
+	int ret;
+
+	ret = regmap_bulk_read(sen0322->regmap, SEN0322_REG_DATA, data,
+			       sizeof(data));
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * The actual value in the registers is:
+	 *	val = data[0] + data[1] / 10 + data[2] / 100
+	 * but it is multiplied by 100 here to avoid floating-point math
+	 * and the scale is divided by 100 to compensate this.
+	 */
+	return data[0] * 100 + data[1] * 10 + data[2];
+}
+
+static int sen0322_read_scale(struct sen0322 *sen0322, int *num, int *den)
+{
+	u32 val;
+	int ret;
+
+	ret = regmap_read(sen0322->regmap, SEN0322_REG_COEFF, &val);
+	if (ret < 0)
+		return ret;
+
+	if (val) {
+		*num = val;
+		*den = 100000;	/* Coeff is scaled by 1000 at calibration. */
+	} else { /* The device is not calibrated, using the factory-defaults. */
+		*num = 209;	/* Oxygen content in the atmosphere is 20.9%. */
+		*den = 120000;	/* Output of the sensor at 20.9% is 120 uA. */
+	}
+
+	dev_dbg(regmap_get_device(sen0322->regmap), "scale: %d/%d\n",
+		*num, *den);
+
+	return 0;
+}
+
+static int sen0322_read_raw(struct iio_dev *iio_dev,
+			    const struct iio_chan_spec *chan,
+			    int *val, int *val2, long mask)
+{
+	struct sen0322 *sen0322 = iio_priv(iio_dev);
+	int ret;
+
+	if (chan->type != IIO_CONCENTRATION)
+		return -EINVAL;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = sen0322_read_data(sen0322);
+		if (ret < 0)
+			return ret;
+
+		*val = ret;
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SCALE:
+		ret = sen0322_read_scale(sen0322, val, val2);
+		if (ret < 0)
+			return ret;
+
+		return IIO_VAL_FRACTIONAL;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info sen0322_info = {
+	.read_raw = sen0322_read_raw,
+};
+
+static const struct regmap_config sen0322_regmap_conf = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static const struct iio_chan_spec sen0322_channel = {
+	.type = IIO_CONCENTRATION,
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+			      BIT(IIO_CHAN_INFO_SCALE),
+};
+
+static int sen0322_probe(struct i2c_client *client)
+{
+	struct sen0322 *sen0322;
+	struct iio_dev *iio_dev;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+		return -ENODEV;
+
+	iio_dev = devm_iio_device_alloc(&client->dev, sizeof(*sen0322));
+	if (!iio_dev)
+		return -ENOMEM;
+
+	sen0322 = iio_priv(iio_dev);
+
+	sen0322->regmap = devm_regmap_init_i2c(client, &sen0322_regmap_conf);
+	if (IS_ERR(sen0322->regmap))
+		return PTR_ERR(sen0322->regmap);
+
+	iio_dev->info = &sen0322_info;
+	iio_dev->name = "sen0322";
+	iio_dev->channels = &sen0322_channel;
+	iio_dev->num_channels = 1;
+	iio_dev->modes = INDIO_DIRECT_MODE;
+
+	return devm_iio_device_register(&client->dev, iio_dev);
+}
+
+static const struct of_device_id sen0322_of_match[] = {
+	{ .compatible = "dfrobot,sen0322" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, sen0322_of_match);
+
+static struct i2c_driver sen0322_driver = {
+	.driver = {
+		.name = "sen0322",
+		.of_match_table = sen0322_of_match,
+	},
+	.probe = sen0322_probe,
+};
+module_i2c_driver(sen0322_driver);
+
+MODULE_AUTHOR("Tóth János <gomba007@gmail.com>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("SEN0322 oxygen sensor driver");
diff --git a/drivers/iio/chemical/sgp30.c b/drivers/iio/chemical/sgp30.c
new file mode 100644
index 000000000..379c1c4af
--- /dev/null
+++ b/drivers/iio/chemical/sgp30.c
@@ -0,0 +1,588 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * sgp30.c - Support for Sensirion SGP Gas Sensors
+ *
+ * Copyright (C) 2018 Andreas Brauchli <andreas.brauchli@sensirion.com>
+ *
+ * I2C slave address: 0x58
+ *
+ * Datasheets:
+ * https://www.sensirion.com/file/datasheet_sgp30
+ * https://www.sensirion.com/file/datasheet_sgpc3
+ *
+ * TODO:
+ * - baseline support
+ * - humidity compensation
+ * - power mode switching (SGPC3)
+ */
+
+#include <linux/crc8.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define SGP_WORD_LEN				2
+#define SGP_CRC8_POLYNOMIAL			0x31
+#define SGP_CRC8_INIT				0xff
+#define SGP_CRC8_LEN				1
+#define SGP_CMD(cmd_word)			cpu_to_be16(cmd_word)
+#define SGP_CMD_DURATION_US			12000
+#define SGP_MEASUREMENT_DURATION_US		50000
+#define SGP_CMD_LEN				SGP_WORD_LEN
+#define SGP_CMD_MAX_BUF_SIZE			(SGP_CMD_LEN + 2 * SGP_WORD_LEN)
+#define SGP_MEASUREMENT_LEN			2
+#define SGP30_MEASURE_INTERVAL_HZ		1
+#define SGPC3_MEASURE_INTERVAL_HZ		2
+#define SGP_VERS_PRODUCT(data)	((((data)->feature_set) & 0xf000) >> 12)
+#define SGP_VERS_RESERVED(data)	((((data)->feature_set) & 0x0800) >> 11)
+#define SGP_VERS_GEN(data)	((((data)->feature_set) & 0x0600) >> 9)
+#define SGP_VERS_ENG_BIT(data)	((((data)->feature_set) & 0x0100) >> 8)
+#define SGP_VERS_MAJOR(data)	((((data)->feature_set) & 0x00e0) >> 5)
+#define SGP_VERS_MINOR(data)	(((data)->feature_set) & 0x001f)
+
+DECLARE_CRC8_TABLE(sgp_crc8_table);
+
+enum sgp_product_id {
+	SGP30 = 0,
+	SGPC3,
+};
+
+enum sgp30_channel_idx {
+	SGP30_IAQ_TVOC_IDX = 0,
+	SGP30_IAQ_CO2EQ_IDX,
+	SGP30_SIG_ETOH_IDX,
+	SGP30_SIG_H2_IDX,
+};
+
+enum sgpc3_channel_idx {
+	SGPC3_IAQ_TVOC_IDX = 10,
+	SGPC3_SIG_ETOH_IDX,
+};
+
+enum sgp_cmd {
+	SGP_CMD_IAQ_INIT			= SGP_CMD(0x2003),
+	SGP_CMD_IAQ_MEASURE			= SGP_CMD(0x2008),
+	SGP_CMD_GET_FEATURE_SET			= SGP_CMD(0x202f),
+	SGP_CMD_GET_SERIAL_ID			= SGP_CMD(0x3682),
+
+	SGP30_CMD_MEASURE_SIGNAL		= SGP_CMD(0x2050),
+
+	SGPC3_CMD_MEASURE_RAW			= SGP_CMD(0x2046),
+};
+
+struct sgp_version {
+	u8 major;
+	u8 minor;
+};
+
+struct sgp_crc_word {
+	__be16 value;
+	u8 crc8;
+} __attribute__((__packed__));
+
+union sgp_reading {
+	u8 start;
+	struct sgp_crc_word raw_words[4];
+};
+
+enum _iaq_buffer_state {
+	IAQ_BUFFER_EMPTY = 0,
+	IAQ_BUFFER_DEFAULT_VALS,
+	IAQ_BUFFER_VALID,
+};
+
+struct sgp_data {
+	struct i2c_client *client;
+	struct task_struct *iaq_thread;
+	struct mutex data_lock;
+	unsigned long iaq_init_start_jiffies;
+	unsigned long iaq_defval_skip_jiffies;
+	u16 product_id;
+	u16 feature_set;
+	unsigned long measure_interval_jiffies;
+	enum sgp_cmd iaq_init_cmd;
+	enum sgp_cmd measure_iaq_cmd;
+	enum sgp_cmd measure_gas_signals_cmd;
+	union sgp_reading buffer;
+	union sgp_reading iaq_buffer;
+	enum _iaq_buffer_state iaq_buffer_state;
+};
+
+struct sgp_device {
+	unsigned long product_id;
+	const struct iio_chan_spec *channels;
+	int num_channels;
+};
+
+static const struct sgp_version supported_versions_sgp30[] = {
+	{
+		.major = 1,
+		.minor = 0,
+	},
+};
+
+static const struct sgp_version supported_versions_sgpc3[] = {
+	{
+		.major = 0,
+		.minor = 4,
+	},
+};
+
+static const struct iio_chan_spec sgp30_channels[] = {
+	{
+		.type = IIO_CONCENTRATION,
+		.channel2 = IIO_MOD_VOC,
+		.modified = 1,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+		.address = SGP30_IAQ_TVOC_IDX,
+	},
+	{
+		.type = IIO_CONCENTRATION,
+		.channel2 = IIO_MOD_CO2,
+		.modified = 1,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+		.address = SGP30_IAQ_CO2EQ_IDX,
+	},
+	{
+		.type = IIO_CONCENTRATION,
+		.channel2 = IIO_MOD_ETHANOL,
+		.modified = 1,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.address = SGP30_SIG_ETOH_IDX,
+	},
+	{
+		.type = IIO_CONCENTRATION,
+		.channel2 = IIO_MOD_H2,
+		.modified = 1,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.address = SGP30_SIG_H2_IDX,
+	},
+};
+
+static const struct iio_chan_spec sgpc3_channels[] = {
+	{
+		.type = IIO_CONCENTRATION,
+		.channel2 = IIO_MOD_VOC,
+		.modified = 1,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+		.address = SGPC3_IAQ_TVOC_IDX,
+	},
+	{
+		.type = IIO_CONCENTRATION,
+		.channel2 = IIO_MOD_ETHANOL,
+		.modified = 1,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.address = SGPC3_SIG_ETOH_IDX,
+	},
+};
+
+static const struct sgp_device sgp_devices[] = {
+	[SGP30] = {
+		.product_id = SGP30,
+		.channels = sgp30_channels,
+		.num_channels = ARRAY_SIZE(sgp30_channels),
+	},
+	[SGPC3] = {
+		.product_id = SGPC3,
+		.channels = sgpc3_channels,
+		.num_channels = ARRAY_SIZE(sgpc3_channels),
+	},
+};
+
+/**
+ * sgp_verify_buffer() - verify the checksums of the data buffer words
+ *
+ * @data:       SGP data
+ * @buf:        Raw data buffer
+ * @word_count: Num data words stored in the buffer, excluding CRC bytes
+ *
+ * Return:      0 on success, negative error otherwise.
+ */
+static int sgp_verify_buffer(const struct sgp_data *data,
+			     union sgp_reading *buf, size_t word_count)
+{
+	size_t size = word_count * (SGP_WORD_LEN + SGP_CRC8_LEN);
+	int i;
+	u8 crc;
+	u8 *data_buf = &buf->start;
+
+	for (i = 0; i < size; i += SGP_WORD_LEN + SGP_CRC8_LEN) {
+		crc = crc8(sgp_crc8_table, &data_buf[i], SGP_WORD_LEN,
+			   SGP_CRC8_INIT);
+		if (crc != data_buf[i + SGP_WORD_LEN]) {
+			dev_err(&data->client->dev, "CRC error\n");
+			return -EIO;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * sgp_read_cmd() - reads data from sensor after issuing a command
+ * The caller must hold data->data_lock for the duration of the call.
+ * @data:        SGP data
+ * @cmd:         SGP Command to issue
+ * @buf:         Raw data buffer to use
+ * @word_count:  Num words to read, excluding CRC bytes
+ * @duration_us: Time taken to sensor to take a reading and data to be ready.
+ *
+ * Return:       0 on success, negative error otherwise.
+ */
+static int sgp_read_cmd(struct sgp_data *data, enum sgp_cmd cmd,
+			union sgp_reading *buf, size_t word_count,
+			unsigned long duration_us)
+{
+	int ret;
+	struct i2c_client *client = data->client;
+	size_t size = word_count * (SGP_WORD_LEN + SGP_CRC8_LEN);
+	u8 *data_buf;
+
+	ret = i2c_master_send(client, (const char *)&cmd, SGP_CMD_LEN);
+	if (ret != SGP_CMD_LEN)
+		return -EIO;
+	usleep_range(duration_us, duration_us + 1000);
+
+	if (word_count == 0)
+		return 0;
+
+	data_buf = &buf->start;
+	ret = i2c_master_recv(client, data_buf, size);
+	if (ret < 0)
+		return ret;
+	if (ret != size)
+		return -EIO;
+
+	return sgp_verify_buffer(data, buf, word_count);
+}
+
+/**
+ * sgp_measure_iaq() - measure and retrieve IAQ values from sensor
+ * The caller must hold data->data_lock for the duration of the call.
+ * @data:       SGP data
+ *
+ * Return:      0 on success, -EBUSY on default values, negative error
+ *              otherwise.
+ */
+
+static int sgp_measure_iaq(struct sgp_data *data)
+{
+	int ret;
+	/* data contains default values */
+	bool default_vals = !time_after(jiffies, data->iaq_init_start_jiffies +
+						 data->iaq_defval_skip_jiffies);
+
+	ret = sgp_read_cmd(data, data->measure_iaq_cmd, &data->iaq_buffer,
+			   SGP_MEASUREMENT_LEN, SGP_MEASUREMENT_DURATION_US);
+	if (ret < 0)
+		return ret;
+
+	data->iaq_buffer_state = IAQ_BUFFER_DEFAULT_VALS;
+
+	if (default_vals)
+		return -EBUSY;
+
+	data->iaq_buffer_state = IAQ_BUFFER_VALID;
+
+	return 0;
+}
+
+static void sgp_iaq_thread_sleep_until(const struct sgp_data *data,
+				       unsigned long sleep_jiffies)
+{
+	const long IAQ_POLL = 50000;
+
+	while (!time_after(jiffies, sleep_jiffies)) {
+		usleep_range(IAQ_POLL, IAQ_POLL + 10000);
+		if (kthread_should_stop() || data->iaq_init_start_jiffies == 0)
+			return;
+	}
+}
+
+static int sgp_iaq_threadfn(void *p)
+{
+	struct sgp_data *data = (struct sgp_data *)p;
+	unsigned long next_update_jiffies;
+	int ret;
+
+	while (!kthread_should_stop()) {
+		mutex_lock(&data->data_lock);
+		if (data->iaq_init_start_jiffies == 0) {
+			ret = sgp_read_cmd(data, data->iaq_init_cmd, NULL, 0,
+					   SGP_CMD_DURATION_US);
+			if (ret < 0)
+				goto unlock_sleep_continue;
+			data->iaq_init_start_jiffies = jiffies;
+		}
+
+		ret = sgp_measure_iaq(data);
+		if (ret && ret != -EBUSY) {
+			dev_warn(&data->client->dev,
+				 "IAQ measurement error [%d]\n", ret);
+		}
+unlock_sleep_continue:
+		next_update_jiffies = jiffies + data->measure_interval_jiffies;
+		mutex_unlock(&data->data_lock);
+		sgp_iaq_thread_sleep_until(data, next_update_jiffies);
+	}
+
+	return 0;
+}
+
+static int sgp_read_raw(struct iio_dev *indio_dev,
+			struct iio_chan_spec const *chan, int *val,
+			int *val2, long mask)
+{
+	struct sgp_data *data = iio_priv(indio_dev);
+	struct sgp_crc_word *words;
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_PROCESSED:
+		mutex_lock(&data->data_lock);
+		if (data->iaq_buffer_state != IAQ_BUFFER_VALID) {
+			mutex_unlock(&data->data_lock);
+			return -EBUSY;
+		}
+		words = data->iaq_buffer.raw_words;
+		switch (chan->address) {
+		case SGP30_IAQ_TVOC_IDX:
+		case SGPC3_IAQ_TVOC_IDX:
+			*val = 0;
+			*val2 = be16_to_cpu(words[1].value);
+			ret = IIO_VAL_INT_PLUS_NANO;
+			break;
+		case SGP30_IAQ_CO2EQ_IDX:
+			*val = 0;
+			*val2 = be16_to_cpu(words[0].value);
+			ret = IIO_VAL_INT_PLUS_MICRO;
+			break;
+		default:
+			ret = -EINVAL;
+			break;
+		}
+		mutex_unlock(&data->data_lock);
+		break;
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&data->data_lock);
+		if (chan->address == SGPC3_SIG_ETOH_IDX) {
+			if (data->iaq_buffer_state == IAQ_BUFFER_EMPTY)
+				ret = -EBUSY;
+			else
+				ret = 0;
+			words = data->iaq_buffer.raw_words;
+		} else {
+			ret = sgp_read_cmd(data, data->measure_gas_signals_cmd,
+					   &data->buffer, SGP_MEASUREMENT_LEN,
+					   SGP_MEASUREMENT_DURATION_US);
+			words = data->buffer.raw_words;
+		}
+		if (ret) {
+			mutex_unlock(&data->data_lock);
+			return ret;
+		}
+
+		switch (chan->address) {
+		case SGP30_SIG_ETOH_IDX:
+			*val = be16_to_cpu(words[1].value);
+			ret = IIO_VAL_INT;
+			break;
+		case SGPC3_SIG_ETOH_IDX:
+		case SGP30_SIG_H2_IDX:
+			*val = be16_to_cpu(words[0].value);
+			ret = IIO_VAL_INT;
+			break;
+		default:
+			ret = -EINVAL;
+			break;
+		}
+		mutex_unlock(&data->data_lock);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return ret;
+}
+
+static int sgp_check_compat(struct sgp_data *data,
+			    unsigned int product_id)
+{
+	struct device *dev = &data->client->dev;
+	const struct sgp_version *supported_versions;
+	u16 ix, num_fs;
+	u16 product, generation, major, minor;
+
+	/* driver does not match product */
+	generation = SGP_VERS_GEN(data);
+	if (generation != 0) {
+		dev_err(dev,
+			"incompatible product generation %d != 0", generation);
+		return -ENODEV;
+	}
+
+	product = SGP_VERS_PRODUCT(data);
+	if (product != product_id) {
+		dev_err(dev, "sensor reports a different product: 0x%04x\n",
+			product);
+		return -ENODEV;
+	}
+
+	if (SGP_VERS_RESERVED(data))
+		dev_warn(dev, "reserved bit is set\n");
+
+	/* engineering samples are not supported: no interface guarantees */
+	if (SGP_VERS_ENG_BIT(data))
+		return -ENODEV;
+
+	switch (product) {
+	case SGP30:
+		supported_versions = supported_versions_sgp30;
+		num_fs = ARRAY_SIZE(supported_versions_sgp30);
+		break;
+	case SGPC3:
+		supported_versions = supported_versions_sgpc3;
+		num_fs = ARRAY_SIZE(supported_versions_sgpc3);
+		break;
+	default:
+		return -ENODEV;
+	}
+
+	major = SGP_VERS_MAJOR(data);
+	minor = SGP_VERS_MINOR(data);
+	for (ix = 0; ix < num_fs; ix++) {
+		if (major == supported_versions[ix].major &&
+		    minor >= supported_versions[ix].minor)
+			return 0;
+	}
+	dev_err(dev, "unsupported sgp version: %d.%d\n", major, minor);
+
+	return -ENODEV;
+}
+
+static void sgp_init(struct sgp_data *data)
+{
+	data->iaq_init_cmd = SGP_CMD_IAQ_INIT;
+	data->iaq_init_start_jiffies = 0;
+	data->iaq_buffer_state = IAQ_BUFFER_EMPTY;
+	switch (SGP_VERS_PRODUCT(data)) {
+	case SGP30:
+		data->measure_interval_jiffies = SGP30_MEASURE_INTERVAL_HZ * HZ;
+		data->measure_iaq_cmd = SGP_CMD_IAQ_MEASURE;
+		data->measure_gas_signals_cmd = SGP30_CMD_MEASURE_SIGNAL;
+		data->product_id = SGP30;
+		data->iaq_defval_skip_jiffies = 15 * HZ;
+		break;
+	case SGPC3:
+		data->measure_interval_jiffies = SGPC3_MEASURE_INTERVAL_HZ * HZ;
+		data->measure_iaq_cmd = SGPC3_CMD_MEASURE_RAW;
+		data->measure_gas_signals_cmd = SGPC3_CMD_MEASURE_RAW;
+		data->product_id = SGPC3;
+		data->iaq_defval_skip_jiffies =
+			43 * data->measure_interval_jiffies;
+		break;
+	}
+}
+
+static const struct iio_info sgp_info = {
+	.read_raw	= sgp_read_raw,
+};
+
+static const struct of_device_id sgp_dt_ids[] = {
+	{ .compatible = "sensirion,sgp30", .data = &sgp_devices[SGP30] },
+	{ .compatible = "sensirion,sgpc3", .data = &sgp_devices[SGPC3] },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, sgp_dt_ids);
+
+static int sgp_probe(struct i2c_client *client)
+{
+	const struct i2c_device_id *id = i2c_client_get_device_id(client);
+	const struct sgp_device *match_data;
+	struct device *dev = &client->dev;
+	struct iio_dev *indio_dev;
+	struct sgp_data *data;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	match_data = i2c_get_match_data(client);
+
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;
+	crc8_populate_msb(sgp_crc8_table, SGP_CRC8_POLYNOMIAL);
+	mutex_init(&data->data_lock);
+
+	/* get feature set version and write it to client data */
+	ret = sgp_read_cmd(data, SGP_CMD_GET_FEATURE_SET, &data->buffer, 1,
+			   SGP_CMD_DURATION_US);
+	if (ret < 0)
+		return ret;
+
+	data->feature_set = be16_to_cpu(data->buffer.raw_words[0].value);
+
+	ret = sgp_check_compat(data, match_data->product_id);
+	if (ret)
+		return ret;
+
+	indio_dev->info = &sgp_info;
+	indio_dev->name = id->name;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = match_data->channels;
+	indio_dev->num_channels = match_data->num_channels;
+
+	sgp_init(data);
+
+	ret = devm_iio_device_register(dev, indio_dev);
+	if (ret) {
+		dev_err(dev, "failed to register iio device\n");
+		return ret;
+	}
+
+	data->iaq_thread = kthread_run(sgp_iaq_threadfn, data,
+				       "%s-iaq", data->client->name);
+	if (IS_ERR(data->iaq_thread))
+		return dev_err_probe(dev, PTR_ERR(data->iaq_thread),
+				     "failed to start IAQ thread\n");
+
+	return 0;
+}
+
+static void sgp_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct sgp_data *data = iio_priv(indio_dev);
+
+	if (data->iaq_thread)
+		kthread_stop(data->iaq_thread);
+}
+
+static const struct i2c_device_id sgp_id[] = {
+	{ .name = "sgp30", .driver_data = (kernel_ulong_t)&sgp_devices[SGP30] },
+	{ .name = "sgpc3", .driver_data = (kernel_ulong_t)&sgp_devices[SGPC3] },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, sgp_id);
+
+static struct i2c_driver sgp_driver = {
+	.driver = {
+		.name = "sgp30",
+		.of_match_table = sgp_dt_ids,
+	},
+	.probe = sgp_probe,
+	.remove = sgp_remove,
+	.id_table = sgp_id,
+};
+module_i2c_driver(sgp_driver);
+
+MODULE_AUTHOR("Andreas Brauchli <andreas.brauchli@sensirion.com>");
+MODULE_AUTHOR("Pascal Sachs <pascal.sachs@sensirion.com>");
+MODULE_DESCRIPTION("Sensirion SGP gas sensors");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/chemical/sgp40.c b/drivers/iio/chemical/sgp40.c
new file mode 100644
index 000000000..b2b5e32a9
--- /dev/null
+++ b/drivers/iio/chemical/sgp40.c
@@ -0,0 +1,383 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * sgp40.c - Support for Sensirion SGP40 Gas Sensor
+ *
+ * Copyright (C) 2021 Andreas Klinger <ak@it-klinger.de>
+ *
+ * I2C slave address: 0x59
+ *
+ * Datasheet can be found here:
+ * https://www.sensirion.com/file/datasheet_sgp40
+ *
+ * There are two functionalities supported:
+ *
+ * 1) read raw logarithmic resistance value from sensor
+ *    --> useful to pass it to the algorithm of the sensor vendor for
+ *    measuring deteriorations and improvements of air quality.
+ *    It can be read from the attribute in_resistance_raw.
+ *
+ * 2) calculate an estimated absolute voc index (in_concentration_input)
+ *    with 0 - 500 index points) for measuring the air quality.
+ *    For this purpose the value of the resistance for which the voc index
+ *    will be 250 can be set up using in_resistance_calibbias (default 30000).
+ *
+ *    The voc index is calculated as:
+ *      x = (in_resistance_raw - in_resistance_calibbias) * 0.65
+ *      in_concentration_input = 500 / (1 + e^x)
+ *
+ * Compensation values of relative humidity and temperature can be set up
+ * by writing to the out values of temp and humidityrelative.
+ */
+
+#include <linux/delay.h>
+#include <linux/crc8.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+
+/*
+ * floating point calculation of voc is done as integer
+ * where numbers are multiplied by 1 << SGP40_CALC_POWER
+ */
+#define SGP40_CALC_POWER	14
+
+#define SGP40_CRC8_POLYNOMIAL	0x31
+#define SGP40_CRC8_INIT		0xff
+
+DECLARE_CRC8_TABLE(sgp40_crc8_table);
+
+struct sgp40_data {
+	struct device		*dev;
+	struct i2c_client	*client;
+	int			rht;
+	int			temp;
+	int			res_calibbias;
+	/* Prevent concurrent access to rht, tmp, calibbias */
+	struct mutex		lock;
+};
+
+struct sgp40_tg_measure {
+	u8	command[2];
+	__be16	rht_ticks;
+	u8	rht_crc;
+	__be16	temp_ticks;
+	u8	temp_crc;
+} __packed;
+
+struct sgp40_tg_result {
+	__be16	res_ticks;
+	u8	res_crc;
+} __packed;
+
+static const struct iio_chan_spec sgp40_channels[] = {
+	{
+		.type = IIO_CONCENTRATION,
+		.channel2 = IIO_MOD_VOC,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+	},
+	{
+		.type = IIO_RESISTANCE,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+			BIT(IIO_CHAN_INFO_CALIBBIAS),
+	},
+	{
+		.type = IIO_TEMP,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.output = 1,
+	},
+	{
+		.type = IIO_HUMIDITYRELATIVE,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.output = 1,
+	},
+};
+
+/*
+ * taylor approximation of e^x:
+ * y = 1 + x + x^2 / 2 + x^3 / 6 + x^4 / 24 + ... + x^n / n!
+ *
+ * Because we are calculating x real value multiplied by 2^power we get
+ * an additional 2^power^n to divide for every element. For a reasonable
+ * precision this would overflow after a few iterations. Therefore we
+ * divide the x^n part whenever its about to overflow (xmax).
+ */
+
+static u32 sgp40_exp(int exp, u32 power, u32 rounds)
+{
+        u32 x, y, xp;
+        u32 factorial, divider, xmax;
+        int sign = 1;
+	int i;
+
+        if (exp == 0)
+                return 1 << power;
+        else if (exp < 0) {
+                sign = -1;
+                exp *= -1;
+        }
+
+        xmax = 0x7FFFFFFF / exp;
+        x = exp;
+        xp = 1;
+        factorial = 1;
+        y = 1 << power;
+        divider = 0;
+
+        for (i = 1; i <= rounds; i++) {
+                xp *= x;
+                factorial *= i;
+                y += (xp >> divider) / factorial;
+                divider += power;
+                /* divide when next multiplication would overflow */
+                if (xp >= xmax) {
+                        xp >>= power;
+                        divider -= power;
+                }
+        }
+
+        if (sign == -1)
+                return (1 << (power * 2)) / y;
+        else
+                return y;
+}
+
+static int sgp40_calc_voc(struct sgp40_data *data, u16 resistance_raw, int *voc)
+{
+	int x;
+	u32 exp = 0;
+
+	/* we calculate as a multiple of 16384 (2^14) */
+	mutex_lock(&data->lock);
+	x = ((int)resistance_raw - data->res_calibbias) * 106;
+	mutex_unlock(&data->lock);
+
+	/* voc = 500 / (1 + e^x) */
+	exp = sgp40_exp(x, SGP40_CALC_POWER, 18);
+	*voc = 500 * ((1 << (SGP40_CALC_POWER * 2)) / ((1<<SGP40_CALC_POWER) + exp));
+
+	dev_dbg(data->dev, "raw: %d res_calibbias: %d x: %d exp: %d voc: %d\n",
+				resistance_raw, data->res_calibbias, x, exp, *voc);
+
+	return 0;
+}
+
+static int sgp40_measure_resistance_raw(struct sgp40_data *data, u16 *resistance_raw)
+{
+	int ret;
+	struct i2c_client *client = data->client;
+	u32 ticks;
+	u16 ticks16;
+	u8 crc;
+	struct sgp40_tg_measure tg = {.command = {0x26, 0x0F}};
+	struct sgp40_tg_result tgres;
+
+	mutex_lock(&data->lock);
+
+	ticks = (data->rht / 10) * 65535 / 10000;
+	ticks16 = (u16)clamp(ticks, 0u, 65535u); /* clamp between 0 .. 100 %rH */
+	tg.rht_ticks = cpu_to_be16(ticks16);
+	tg.rht_crc = crc8(sgp40_crc8_table, (u8 *)&tg.rht_ticks, 2, SGP40_CRC8_INIT);
+
+	ticks = ((data->temp + 45000) / 10 ) * 65535 / 17500;
+	ticks16 = (u16)clamp(ticks, 0u, 65535u); /* clamp between -45 .. +130 °C */
+	tg.temp_ticks = cpu_to_be16(ticks16);
+	tg.temp_crc = crc8(sgp40_crc8_table, (u8 *)&tg.temp_ticks, 2, SGP40_CRC8_INIT);
+
+	mutex_unlock(&data->lock);
+
+	ret = i2c_master_send(client, (const char *)&tg, sizeof(tg));
+	if (ret != sizeof(tg)) {
+		dev_warn(data->dev, "i2c_master_send ret: %d sizeof: %zu\n", ret, sizeof(tg));
+		return -EIO;
+	}
+	msleep(30);
+
+	ret = i2c_master_recv(client, (u8 *)&tgres, sizeof(tgres));
+	if (ret < 0)
+		return ret;
+	if (ret != sizeof(tgres)) {
+		dev_warn(data->dev, "i2c_master_recv ret: %d sizeof: %zu\n", ret, sizeof(tgres));
+		return -EIO;
+	}
+
+	crc = crc8(sgp40_crc8_table, (u8 *)&tgres.res_ticks, 2, SGP40_CRC8_INIT);
+	if (crc != tgres.res_crc) {
+		dev_err(data->dev, "CRC error while measure-raw\n");
+		return -EIO;
+	}
+
+	*resistance_raw = be16_to_cpu(tgres.res_ticks);
+
+	return 0;
+}
+
+static int sgp40_read_raw(struct iio_dev *indio_dev,
+			struct iio_chan_spec const *chan, int *val,
+			int *val2, long mask)
+{
+	struct sgp40_data *data = iio_priv(indio_dev);
+	int ret, voc;
+	u16 resistance_raw;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		switch (chan->type) {
+		case IIO_RESISTANCE:
+			ret = sgp40_measure_resistance_raw(data, &resistance_raw);
+			if (ret)
+				return ret;
+
+			*val = resistance_raw;
+			return IIO_VAL_INT;
+		case IIO_TEMP:
+			mutex_lock(&data->lock);
+			*val = data->temp;
+			mutex_unlock(&data->lock);
+			return IIO_VAL_INT;
+		case IIO_HUMIDITYRELATIVE:
+			mutex_lock(&data->lock);
+			*val = data->rht;
+			mutex_unlock(&data->lock);
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_PROCESSED:
+		ret = sgp40_measure_resistance_raw(data, &resistance_raw);
+		if (ret)
+			return ret;
+
+		ret = sgp40_calc_voc(data, resistance_raw, &voc);
+		if (ret)
+			return ret;
+
+		*val = voc / (1 << SGP40_CALC_POWER);
+		/*
+		 * calculation should fit into integer, where:
+		 * voc <= (500 * 2^SGP40_CALC_POWER) = 8192000
+		 * (with SGP40_CALC_POWER = 14)
+		 */
+		*val2 = ((voc % (1 << SGP40_CALC_POWER)) * 244) / (1 << (SGP40_CALC_POWER - 12));
+		dev_dbg(data->dev, "voc: %d val: %d.%06d\n", voc, *val, *val2);
+		return IIO_VAL_INT_PLUS_MICRO;
+	case IIO_CHAN_INFO_CALIBBIAS:
+		mutex_lock(&data->lock);
+		*val = data->res_calibbias;
+		mutex_unlock(&data->lock);
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int sgp40_write_raw(struct iio_dev *indio_dev,
+			struct iio_chan_spec const *chan, int val,
+			int val2, long mask)
+{
+	struct sgp40_data *data = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		switch (chan->type) {
+		case IIO_TEMP:
+			if ((val < -45000) || (val > 130000))
+				return -EINVAL;
+
+			mutex_lock(&data->lock);
+			data->temp = val;
+			mutex_unlock(&data->lock);
+			return 0;
+		case IIO_HUMIDITYRELATIVE:
+			if ((val < 0) || (val > 100000))
+				return -EINVAL;
+
+			mutex_lock(&data->lock);
+			data->rht = val;
+			mutex_unlock(&data->lock);
+			return 0;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_CALIBBIAS:
+		if ((val < 20000) || (val > 52768))
+			return -EINVAL;
+
+		mutex_lock(&data->lock);
+		data->res_calibbias = val;
+		mutex_unlock(&data->lock);
+		return 0;
+	}
+	return -EINVAL;
+}
+
+static const struct iio_info sgp40_info = {
+	.read_raw	= sgp40_read_raw,
+	.write_raw	= sgp40_write_raw,
+};
+
+static int sgp40_probe(struct i2c_client *client)
+{
+	const struct i2c_device_id *id = i2c_client_get_device_id(client);
+	struct device *dev = &client->dev;
+	struct iio_dev *indio_dev;
+	struct sgp40_data *data;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	data->client = client;
+	data->dev = dev;
+
+	crc8_populate_msb(sgp40_crc8_table, SGP40_CRC8_POLYNOMIAL);
+
+	mutex_init(&data->lock);
+
+	/* set default values */
+	data->rht = 50000;		/* 50 % */
+	data->temp = 25000;		/* 25 °C */
+	data->res_calibbias = 30000;	/* resistance raw value for voc index of 250 */
+
+	indio_dev->info = &sgp40_info;
+	indio_dev->name = id->name;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = sgp40_channels;
+	indio_dev->num_channels = ARRAY_SIZE(sgp40_channels);
+
+	ret = devm_iio_device_register(dev, indio_dev);
+	if (ret)
+		dev_err(dev, "failed to register iio device\n");
+
+	return ret;
+}
+
+static const struct i2c_device_id sgp40_id[] = {
+	{ .name = "sgp40" },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(i2c, sgp40_id);
+
+static const struct of_device_id sgp40_dt_ids[] = {
+	{ .compatible = "sensirion,sgp40" },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(of, sgp40_dt_ids);
+
+static struct i2c_driver sgp40_driver = {
+	.driver = {
+		.name = "sgp40",
+		.of_match_table = sgp40_dt_ids,
+	},
+	.probe = sgp40_probe,
+	.id_table = sgp40_id,
+};
+module_i2c_driver(sgp40_driver);
+
+MODULE_AUTHOR("Andreas Klinger <ak@it-klinger.de>");
+MODULE_DESCRIPTION("Sensirion SGP40 gas sensor");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/chemical/sps30.c b/drivers/iio/chemical/sps30.c
new file mode 100644
index 000000000..8e15baa31
--- /dev/null
+++ b/drivers/iio/chemical/sps30.c
@@ -0,0 +1,375 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Sensirion SPS30 particulate matter sensor driver
+ *
+ * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
+ */
+
+#include <linux/cleanup.h>
+#include <linux/crc8.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include "sps30.h"
+
+/* sensor measures reliably up to 3000 ug / m3 */
+#define SPS30_MAX_PM 3000
+/* minimum and maximum self cleaning periods in seconds */
+#define SPS30_AUTO_CLEANING_PERIOD_MIN 0
+#define SPS30_AUTO_CLEANING_PERIOD_MAX 604800
+
+enum {
+	PM1,
+	PM2P5,
+	PM4,
+	PM10,
+};
+
+enum {
+	RESET,
+	MEASURING,
+};
+
+static s32 sps30_float_to_int_clamped(__be32 *fp)
+{
+	int val = be32_to_cpup(fp);
+	int mantissa = val & GENMASK(22, 0);
+	/* this is fine since passed float is always non-negative */
+	int exp = val >> 23;
+	int fraction, shift;
+
+	/* special case 0 */
+	if (!exp && !mantissa)
+		return 0;
+
+	exp -= 127;
+	if (exp < 0) {
+		/* return values ranging from 1 to 99 */
+		return ((((1 << 23) + mantissa) * 100) >> 23) >> (-exp);
+	}
+
+	/* return values ranging from 100 to 300000 */
+	shift = 23 - exp;
+	val = (1 << exp) + (mantissa >> shift);
+	if (val >= SPS30_MAX_PM)
+		return SPS30_MAX_PM * 100;
+
+	fraction = mantissa & GENMASK(shift - 1, 0);
+
+	return val * 100 + ((fraction * 100) >> shift);
+}
+
+static int sps30_do_meas(struct sps30_state *state, s32 *data, int size)
+{
+	int i, ret;
+
+	guard(mutex)(&state->lock);
+
+	if (state->state == RESET) {
+		ret = state->ops->start_meas(state);
+		if (ret)
+			return ret;
+
+		state->state = MEASURING;
+	}
+
+	ret = state->ops->read_meas(state, (__be32 *)data, size);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < size; i++)
+		data[i] = sps30_float_to_int_clamped((__be32 *)&data[i]);
+
+	return 0;
+}
+
+static int sps30_do_reset(struct sps30_state *state)
+{
+	int ret;
+
+	ret = state->ops->reset(state);
+	if (ret)
+		return ret;
+
+	state->state = RESET;
+
+	return 0;
+}
+
+static irqreturn_t sps30_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct sps30_state *state = iio_priv(indio_dev);
+	int ret;
+	struct {
+		s32 data[4]; /* PM1, PM2P5, PM4, PM10 */
+		aligned_s64 ts;
+	} scan;
+
+	ret = sps30_do_meas(state, scan.data, ARRAY_SIZE(scan.data));
+	if (ret)
+		goto err;
+
+	iio_push_to_buffers_with_ts(indio_dev, &scan, sizeof(scan),
+				    iio_get_time_ns(indio_dev));
+err:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int sps30_read_raw(struct iio_dev *indio_dev,
+			  struct iio_chan_spec const *chan,
+			  int *val, int *val2, long mask)
+{
+	struct sps30_state *state = iio_priv(indio_dev);
+	int data[4], ret = -EINVAL;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_PROCESSED:
+		switch (chan->type) {
+		case IIO_MASSCONCENTRATION:
+			/* read up to the number of bytes actually needed */
+			switch (chan->channel2) {
+			case IIO_MOD_PM1:
+				ret = sps30_do_meas(state, data, 1);
+				break;
+			case IIO_MOD_PM2P5:
+				ret = sps30_do_meas(state, data, 2);
+				break;
+			case IIO_MOD_PM4:
+				ret = sps30_do_meas(state, data, 3);
+				break;
+			case IIO_MOD_PM10:
+				ret = sps30_do_meas(state, data, 4);
+				break;
+			}
+			if (ret)
+				return ret;
+
+			*val = data[chan->address] / 100;
+			*val2 = (data[chan->address] % 100) * 10000;
+
+			return IIO_VAL_INT_PLUS_MICRO;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_MASSCONCENTRATION:
+			switch (chan->channel2) {
+			case IIO_MOD_PM1:
+			case IIO_MOD_PM2P5:
+			case IIO_MOD_PM4:
+			case IIO_MOD_PM10:
+				*val = 0;
+				*val2 = 10000;
+
+				return IIO_VAL_INT_PLUS_MICRO;
+			default:
+				return -EINVAL;
+			}
+		default:
+			return -EINVAL;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static ssize_t start_cleaning_store(struct device *dev,
+				    struct device_attribute *attr,
+				    const char *buf, size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct sps30_state *state = iio_priv(indio_dev);
+	int val, ret;
+
+	if (kstrtoint(buf, 0, &val) || val != 1)
+		return -EINVAL;
+
+	guard(mutex)(&state->lock);
+
+	ret = state->ops->clean_fan(state);
+	if (ret)
+		return ret;
+
+	return len;
+}
+
+static ssize_t cleaning_period_show(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct sps30_state *state = iio_priv(indio_dev);
+	__be32 val;
+	int ret;
+
+	guard(mutex)(&state->lock);
+
+	ret = state->ops->read_cleaning_period(state, &val);
+	if (ret)
+		return ret;
+
+	return sysfs_emit(buf, "%d\n", be32_to_cpu(val));
+}
+
+static ssize_t cleaning_period_store(struct device *dev, struct device_attribute *attr,
+				     const char *buf, size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct sps30_state *state = iio_priv(indio_dev);
+	int val, ret;
+
+	if (kstrtoint(buf, 0, &val))
+		return -EINVAL;
+
+	if ((val < SPS30_AUTO_CLEANING_PERIOD_MIN) ||
+	    (val > SPS30_AUTO_CLEANING_PERIOD_MAX))
+		return -EINVAL;
+
+	guard(mutex)(&state->lock);
+
+	ret = state->ops->write_cleaning_period(state, cpu_to_be32(val));
+	if (ret)
+		return ret;
+
+	msleep(20);
+
+	/*
+	 * sensor requires reset in order to return up to date self cleaning
+	 * period
+	 */
+	ret = sps30_do_reset(state);
+	if (ret)
+		dev_warn(dev,
+			 "period changed but reads will return the old value\n");
+
+	return len;
+}
+
+static ssize_t cleaning_period_available_show(struct device *dev,
+					      struct device_attribute *attr,
+					      char *buf)
+{
+	return sysfs_emit(buf, "[%d %d %d]\n",
+			  SPS30_AUTO_CLEANING_PERIOD_MIN, 1,
+			  SPS30_AUTO_CLEANING_PERIOD_MAX);
+}
+
+static IIO_DEVICE_ATTR_WO(start_cleaning, 0);
+static IIO_DEVICE_ATTR_RW(cleaning_period, 0);
+static IIO_DEVICE_ATTR_RO(cleaning_period_available, 0);
+
+static struct attribute *sps30_attrs[] = {
+	&iio_dev_attr_start_cleaning.dev_attr.attr,
+	&iio_dev_attr_cleaning_period.dev_attr.attr,
+	&iio_dev_attr_cleaning_period_available.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group sps30_attr_group = {
+	.attrs = sps30_attrs,
+};
+
+static const struct iio_info sps30_info = {
+	.attrs = &sps30_attr_group,
+	.read_raw = sps30_read_raw,
+};
+
+#define SPS30_CHAN(_index, _mod) { \
+	.type = IIO_MASSCONCENTRATION, \
+	.modified = 1, \
+	.channel2 = IIO_MOD_ ## _mod, \
+	.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+	.address = _mod, \
+	.scan_index = _index, \
+	.scan_type = { \
+		.sign = 'u', \
+		.realbits = 19, \
+		.storagebits = 32, \
+		.endianness = IIO_CPU, \
+	}, \
+}
+
+static const struct iio_chan_spec sps30_channels[] = {
+	SPS30_CHAN(0, PM1),
+	SPS30_CHAN(1, PM2P5),
+	SPS30_CHAN(2, PM4),
+	SPS30_CHAN(3, PM10),
+	IIO_CHAN_SOFT_TIMESTAMP(4),
+};
+
+static void sps30_devm_stop_meas(void *data)
+{
+	struct sps30_state *state = data;
+
+	if (state->state == MEASURING)
+		state->ops->stop_meas(state);
+}
+
+static const unsigned long sps30_scan_masks[] = { 0x0f, 0x00 };
+
+int sps30_probe(struct device *dev, const char *name, void *priv, const struct sps30_ops *ops)
+{
+	struct iio_dev *indio_dev;
+	struct sps30_state *state;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	dev_set_drvdata(dev, indio_dev);
+
+	state = iio_priv(indio_dev);
+	state->dev = dev;
+	state->priv = priv;
+	state->ops = ops;
+	mutex_init(&state->lock);
+
+	indio_dev->info = &sps30_info;
+	indio_dev->name = name;
+	indio_dev->channels = sps30_channels;
+	indio_dev->num_channels = ARRAY_SIZE(sps30_channels);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->available_scan_masks = sps30_scan_masks;
+
+	ret = sps30_do_reset(state);
+	if (ret) {
+		dev_err(dev, "failed to reset device\n");
+		return ret;
+	}
+
+	ret = state->ops->show_info(state);
+	if (ret) {
+		dev_err(dev, "failed to read device info\n");
+		return ret;
+	}
+
+	ret = devm_add_action_or_reset(dev, sps30_devm_stop_meas, state);
+	if (ret)
+		return ret;
+
+	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
+					      sps30_trigger_handler, NULL);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+EXPORT_SYMBOL_NS_GPL(sps30_probe, "IIO_SPS30");
+
+MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
+MODULE_DESCRIPTION("Sensirion SPS30 particulate matter sensor driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/chemical/sps30.h b/drivers/iio/chemical/sps30.h
new file mode 100644
index 000000000..a58ee43cf
--- /dev/null
+++ b/drivers/iio/chemical/sps30.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _SPS30_H
+#define _SPS30_H
+
+#include <linux/types.h>
+
+struct sps30_state;
+struct sps30_ops {
+	int (*start_meas)(struct sps30_state *state);
+	int (*stop_meas)(struct sps30_state *state);
+	int (*read_meas)(struct sps30_state *state, __be32 *meas, size_t num);
+	int (*reset)(struct sps30_state *state);
+	int (*clean_fan)(struct sps30_state *state);
+	int (*read_cleaning_period)(struct sps30_state *state, __be32 *period);
+	int (*write_cleaning_period)(struct sps30_state *state, __be32 period);
+	int (*show_info)(struct sps30_state *state);
+};
+
+struct sps30_state {
+	/* serialize access to the device */
+	struct mutex lock;
+	struct device *dev;
+	int state;
+	/*
+	 * priv pointer is solely for serdev driver private data. We keep it
+	 * here because driver_data inside dev has been already used for iio and
+	 * struct serdev_device doesn't have one.
+	 */
+	void *priv;
+	const struct sps30_ops *ops;
+};
+
+int sps30_probe(struct device *dev, const char *name, void *priv, const struct sps30_ops *ops);
+
+#endif
diff --git a/drivers/iio/chemical/sps30_i2c.c b/drivers/iio/chemical/sps30_i2c.c
new file mode 100644
index 000000000..2d3a876cc
--- /dev/null
+++ b/drivers/iio/chemical/sps30_i2c.c
@@ -0,0 +1,258 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Sensirion SPS30 particulate matter sensor i2c driver
+ *
+ * Copyright (c) 2020 Tomasz Duszynski <tduszyns@gmail.com>
+ *
+ * I2C slave address: 0x69
+ */
+#include <linux/unaligned.h>
+#include <linux/crc8.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/types.h>
+
+#include "sps30.h"
+
+#define SPS30_I2C_CRC8_POLYNOMIAL 0x31
+/* max number of bytes needed to store PM measurements or serial string */
+#define SPS30_I2C_MAX_BUF_SIZE 48
+
+DECLARE_CRC8_TABLE(sps30_i2c_crc8_table);
+
+#define SPS30_I2C_START_MEAS 0x0010
+#define SPS30_I2C_STOP_MEAS 0x0104
+#define SPS30_I2C_READ_MEAS 0x0300
+#define SPS30_I2C_MEAS_READY 0x0202
+#define SPS30_I2C_RESET 0xd304
+#define SPS30_I2C_CLEAN_FAN 0x5607
+#define SPS30_I2C_PERIOD 0x8004
+#define SPS30_I2C_READ_SERIAL 0xd033
+#define SPS30_I2C_READ_VERSION 0xd100
+
+static int sps30_i2c_xfer(struct sps30_state *state, unsigned char *txbuf, size_t txsize,
+			  unsigned char *rxbuf, size_t rxsize)
+{
+	struct i2c_client *client = to_i2c_client(state->dev);
+	int ret;
+
+	/*
+	 * Sensor does not support repeated start so instead of
+	 * sending two i2c messages in a row we just send one by one.
+	 */
+	ret = i2c_master_send(client, txbuf, txsize);
+	if (ret < 0)
+		return ret;
+	if (ret != txsize)
+		return -EIO;
+
+	if (!rxsize)
+		return 0;
+
+	ret = i2c_master_recv(client, rxbuf, rxsize);
+	if (ret < 0)
+		return ret;
+	if (ret != rxsize)
+		return -EIO;
+
+	return 0;
+}
+
+static int sps30_i2c_command(struct sps30_state *state, u16 cmd, void *arg, size_t arg_size,
+			     void *rsp, size_t rsp_size)
+{
+	/*
+	 * Internally sensor stores measurements in a following manner:
+	 *
+	 * PM1:   upper two bytes, crc8, lower two bytes, crc8
+	 * PM2P5: upper two bytes, crc8, lower two bytes, crc8
+	 * PM4:   upper two bytes, crc8, lower two bytes, crc8
+	 * PM10:  upper two bytes, crc8, lower two bytes, crc8
+	 *
+	 * What follows next are number concentration measurements and
+	 * typical particle size measurement which we omit.
+	 */
+	unsigned char buf[SPS30_I2C_MAX_BUF_SIZE];
+	unsigned char *tmp;
+	unsigned char crc;
+	size_t i;
+	int ret;
+
+	put_unaligned_be16(cmd, buf);
+	i = 2;
+
+	if (rsp) {
+		/* each two bytes are followed by a crc8 */
+		rsp_size += rsp_size / 2;
+	} else {
+		tmp = arg;
+
+		while (arg_size) {
+			buf[i] = *tmp++;
+			buf[i + 1] = *tmp++;
+			buf[i + 2] = crc8(sps30_i2c_crc8_table, buf + i, 2, CRC8_INIT_VALUE);
+			arg_size -= 2;
+			i += 3;
+		}
+	}
+
+	ret = sps30_i2c_xfer(state, buf, i, buf, rsp_size);
+	if (ret)
+		return ret;
+
+	/* validate received data and strip off crc bytes */
+	tmp = rsp;
+	for (i = 0; i < rsp_size; i += 3) {
+		crc = crc8(sps30_i2c_crc8_table, buf + i, 2, CRC8_INIT_VALUE);
+		if (crc != buf[i + 2]) {
+			dev_err(state->dev, "data integrity check failed\n");
+			return -EIO;
+		}
+
+		*tmp++ = buf[i];
+		*tmp++ = buf[i + 1];
+	}
+
+	return 0;
+}
+
+static int sps30_i2c_start_meas(struct sps30_state *state)
+{
+	/* request BE IEEE754 formatted data */
+	unsigned char buf[] = { 0x03, 0x00 };
+
+	return sps30_i2c_command(state, SPS30_I2C_START_MEAS, buf, sizeof(buf), NULL, 0);
+}
+
+static int sps30_i2c_stop_meas(struct sps30_state *state)
+{
+	return sps30_i2c_command(state, SPS30_I2C_STOP_MEAS, NULL, 0, NULL, 0);
+}
+
+static int sps30_i2c_reset(struct sps30_state *state)
+{
+	int ret;
+
+	ret = sps30_i2c_command(state, SPS30_I2C_RESET, NULL, 0, NULL, 0);
+	msleep(500);
+	/*
+	 * Power-on-reset causes sensor to produce some glitch on i2c bus and
+	 * some controllers end up in error state. Recover simply by placing
+	 * some data on the bus, for example STOP_MEAS command, which
+	 * is NOP in this case.
+	 */
+	sps30_i2c_stop_meas(state);
+
+	return ret;
+}
+
+static bool sps30_i2c_meas_ready(struct sps30_state *state)
+{
+	unsigned char buf[2];
+	int ret;
+
+	ret = sps30_i2c_command(state, SPS30_I2C_MEAS_READY, NULL, 0, buf, sizeof(buf));
+	if (ret)
+		return false;
+
+	return buf[1];
+}
+
+static int sps30_i2c_read_meas(struct sps30_state *state, __be32 *meas, size_t num)
+{
+	/* measurements are ready within a second */
+	if (msleep_interruptible(1000))
+		return -EINTR;
+
+	if (!sps30_i2c_meas_ready(state))
+		return -ETIMEDOUT;
+
+	return sps30_i2c_command(state, SPS30_I2C_READ_MEAS, NULL, 0, meas, sizeof(*meas) * num);
+}
+
+static int sps30_i2c_clean_fan(struct sps30_state *state)
+{
+	return sps30_i2c_command(state, SPS30_I2C_CLEAN_FAN, NULL, 0, NULL, 0);
+}
+
+static int sps30_i2c_read_cleaning_period(struct sps30_state *state, __be32 *period)
+{
+	return sps30_i2c_command(state, SPS30_I2C_PERIOD, NULL, 0, period, sizeof(*period));
+}
+
+static int sps30_i2c_write_cleaning_period(struct sps30_state *state, __be32 period)
+{
+	return sps30_i2c_command(state, SPS30_I2C_PERIOD, &period, sizeof(period), NULL, 0);
+}
+
+static int sps30_i2c_show_info(struct sps30_state *state)
+{
+	/* extra nul just in case */
+	unsigned char buf[32 + 1] = { 0x00 };
+	int ret;
+
+	ret = sps30_i2c_command(state, SPS30_I2C_READ_SERIAL, NULL, 0, buf, sizeof(buf) - 1);
+	if (ret)
+		return ret;
+
+	dev_info(state->dev, "serial number: %s\n", buf);
+
+	ret = sps30_i2c_command(state, SPS30_I2C_READ_VERSION, NULL, 0, buf, 2);
+	if (ret)
+		return ret;
+
+	dev_info(state->dev, "fw version: %u.%u\n", buf[0], buf[1]);
+
+	return 0;
+}
+
+static const struct sps30_ops sps30_i2c_ops = {
+	.start_meas = sps30_i2c_start_meas,
+	.stop_meas = sps30_i2c_stop_meas,
+	.read_meas = sps30_i2c_read_meas,
+	.reset = sps30_i2c_reset,
+	.clean_fan = sps30_i2c_clean_fan,
+	.read_cleaning_period = sps30_i2c_read_cleaning_period,
+	.write_cleaning_period = sps30_i2c_write_cleaning_period,
+	.show_info = sps30_i2c_show_info,
+};
+
+static int sps30_i2c_probe(struct i2c_client *client)
+{
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+		return -EOPNOTSUPP;
+
+	crc8_populate_msb(sps30_i2c_crc8_table, SPS30_I2C_CRC8_POLYNOMIAL);
+
+	return sps30_probe(&client->dev, client->name, NULL, &sps30_i2c_ops);
+}
+
+static const struct i2c_device_id sps30_i2c_id[] = {
+	{ .name = "sps30" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, sps30_i2c_id);
+
+static const struct of_device_id sps30_i2c_of_match[] = {
+	{ .compatible = "sensirion,sps30" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, sps30_i2c_of_match);
+
+static struct i2c_driver sps30_i2c_driver = {
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.of_match_table = sps30_i2c_of_match,
+	},
+	.id_table = sps30_i2c_id,
+	.probe = sps30_i2c_probe,
+};
+module_i2c_driver(sps30_i2c_driver);
+
+MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
+MODULE_DESCRIPTION("Sensirion SPS30 particulate matter sensor i2c driver");
+MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS("IIO_SPS30");
diff --git a/drivers/iio/chemical/sps30_serial.c b/drivers/iio/chemical/sps30_serial.c
new file mode 100644
index 000000000..0cdba8703
--- /dev/null
+++ b/drivers/iio/chemical/sps30_serial.c
@@ -0,0 +1,431 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Sensirion SPS30 particulate matter sensor serial driver
+ *
+ * Copyright (c) 2021 Tomasz Duszynski <tduszyns@gmail.com>
+ */
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/iio/iio.h>
+#include <linux/minmax.h>
+#include <linux/module.h>
+#include <linux/serdev.h>
+#include <linux/types.h>
+
+#include "sps30.h"
+
+#define SPS30_SERIAL_DEV_NAME "sps30"
+
+#define SPS30_SERIAL_SOF_EOF 0x7e
+#define SPS30_SERIAL_TIMEOUT msecs_to_jiffies(20)
+#define SPS30_SERIAL_MAX_BUF_SIZE 263
+#define SPS30_SERIAL_ESCAPE_CHAR 0x7d
+
+#define SPS30_SERIAL_FRAME_MIN_SIZE 7
+#define SPS30_SERIAL_FRAME_ADR_OFFSET 1
+#define SPS30_SERIAL_FRAME_CMD_OFFSET 2
+#define SPS30_SERIAL_FRAME_MOSI_LEN_OFFSET 3
+#define SPS30_SERIAL_FRAME_MISO_STATE_OFFSET 3
+#define SPS30_SERIAL_FRAME_MISO_LEN_OFFSET 4
+#define SPS30_SERIAL_FRAME_MISO_DATA_OFFSET 5
+
+#define SPS30_SERIAL_START_MEAS 0x00
+#define SPS30_SERIAL_STOP_MEAS 0x01
+#define SPS30_SERIAL_READ_MEAS 0x03
+#define SPS30_SERIAL_RESET 0xd3
+#define SPS30_SERIAL_CLEAN_FAN 0x56
+#define SPS30_SERIAL_PERIOD 0x80
+#define SPS30_SERIAL_DEV_INFO 0xd0
+#define SPS30_SERIAL_READ_VERSION 0xd1
+
+struct sps30_serial_priv {
+	struct completion new_frame;
+	unsigned char buf[SPS30_SERIAL_MAX_BUF_SIZE];
+	size_t num;
+	bool escaped;
+	bool done;
+};
+
+static int sps30_serial_xfer(struct sps30_state *state, const unsigned char *buf, size_t size)
+{
+	struct serdev_device *serdev = to_serdev_device(state->dev);
+	struct sps30_serial_priv *priv = state->priv;
+	int ret;
+
+	priv->num = 0;
+	priv->escaped = false;
+	priv->done = false;
+
+	ret = serdev_device_write(serdev, buf, size, SPS30_SERIAL_TIMEOUT);
+	if (ret < 0)
+		return ret;
+	if (ret != size)
+		return -EIO;
+
+	ret = wait_for_completion_interruptible_timeout(&priv->new_frame, SPS30_SERIAL_TIMEOUT);
+	if (ret < 0)
+		return ret;
+	if (!ret)
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
+static const struct {
+	u8 byte;
+	u8 byte2;
+} sps30_serial_bytes[] = {
+	{ 0x11, 0x31 },
+	{ 0x13, 0x33 },
+	{ 0x7e, 0x5e },
+	{ 0x7d, 0x5d },
+};
+
+static int sps30_serial_put_byte(u8 *buf, u8 byte)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(sps30_serial_bytes); i++) {
+		if (sps30_serial_bytes[i].byte != byte)
+			continue;
+
+		buf[0] = SPS30_SERIAL_ESCAPE_CHAR;
+		buf[1] = sps30_serial_bytes[i].byte2;
+
+		return 2;
+	}
+
+	buf[0] = byte;
+
+	return 1;
+}
+
+static u8 sps30_serial_get_byte(bool escaped, u8 byte2)
+{
+	int i;
+
+	if (!escaped)
+		return byte2;
+
+	for (i = 0; i < ARRAY_SIZE(sps30_serial_bytes); i++) {
+		if (sps30_serial_bytes[i].byte2 != byte2)
+			continue;
+
+		return sps30_serial_bytes[i].byte;
+	}
+
+	return 0;
+}
+
+static unsigned char sps30_serial_calc_chksum(const unsigned char *buf, size_t num)
+{
+	unsigned int chksum = 0;
+	size_t i;
+
+	for (i = 0; i < num; i++)
+		chksum += buf[i];
+
+	return ~chksum;
+}
+
+static int sps30_serial_prep_frame(u8 *buf, u8 cmd, const u8 *arg,
+				   size_t arg_size)
+{
+	unsigned char chksum;
+	int num = 0;
+	size_t i;
+
+	buf[num++] = SPS30_SERIAL_SOF_EOF;
+	buf[num++] = 0;
+	num += sps30_serial_put_byte(buf + num, cmd);
+	num += sps30_serial_put_byte(buf + num, arg_size);
+
+	for (i = 0; i < arg_size; i++)
+		num += sps30_serial_put_byte(buf + num, arg[i]);
+
+	/* SOF isn't checksummed */
+	chksum = sps30_serial_calc_chksum(buf + 1, num - 1);
+	num += sps30_serial_put_byte(buf + num, chksum);
+	buf[num++] = SPS30_SERIAL_SOF_EOF;
+
+	return num;
+}
+
+static bool sps30_serial_frame_valid(struct sps30_state *state, const unsigned char *buf)
+{
+	struct sps30_serial_priv *priv = state->priv;
+	unsigned char chksum;
+
+	if ((priv->num < SPS30_SERIAL_FRAME_MIN_SIZE) ||
+	    (priv->num != SPS30_SERIAL_FRAME_MIN_SIZE +
+	     priv->buf[SPS30_SERIAL_FRAME_MISO_LEN_OFFSET])) {
+		dev_err(state->dev, "frame has invalid number of bytes\n");
+		return false;
+	}
+
+	if ((priv->buf[SPS30_SERIAL_FRAME_ADR_OFFSET] != buf[SPS30_SERIAL_FRAME_ADR_OFFSET]) ||
+	    (priv->buf[SPS30_SERIAL_FRAME_CMD_OFFSET] != buf[SPS30_SERIAL_FRAME_CMD_OFFSET])) {
+		dev_err(state->dev, "frame has wrong ADR and CMD bytes\n");
+		return false;
+	}
+
+	if (priv->buf[SPS30_SERIAL_FRAME_MISO_STATE_OFFSET]) {
+		dev_err(state->dev, "frame with non-zero state received (0x%02x)\n",
+			priv->buf[SPS30_SERIAL_FRAME_MISO_STATE_OFFSET]);
+		return false;
+	}
+
+	/* SOF, checksum and EOF are not checksummed */
+	chksum = sps30_serial_calc_chksum(priv->buf + 1, priv->num - 3);
+	if (priv->buf[priv->num - 2] != chksum) {
+		dev_err(state->dev, "frame integrity check failed\n");
+		return false;
+	}
+
+	return true;
+}
+
+static int sps30_serial_command(struct sps30_state *state, unsigned char cmd,
+				const void *arg, size_t arg_size, void *rsp, size_t rsp_size)
+{
+	struct sps30_serial_priv *priv = state->priv;
+	unsigned char buf[SPS30_SERIAL_MAX_BUF_SIZE];
+	int ret, size;
+
+	size = sps30_serial_prep_frame(buf, cmd, arg, arg_size);
+	ret = sps30_serial_xfer(state, buf, size);
+	if (ret)
+		return ret;
+
+	if (!sps30_serial_frame_valid(state, buf))
+		return -EIO;
+
+	if (rsp) {
+		rsp_size = min_t(size_t, priv->buf[SPS30_SERIAL_FRAME_MISO_LEN_OFFSET], rsp_size);
+		memcpy(rsp, &priv->buf[SPS30_SERIAL_FRAME_MISO_DATA_OFFSET], rsp_size);
+	}
+
+	return rsp_size;
+}
+
+static size_t sps30_serial_receive_buf(struct serdev_device *serdev,
+				       const u8 *buf, size_t size)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(&serdev->dev);
+	struct sps30_serial_priv *priv;
+	struct sps30_state *state;
+	size_t i;
+	u8 byte;
+
+	if (!indio_dev)
+		return 0;
+
+	state = iio_priv(indio_dev);
+	priv = state->priv;
+
+	/* just in case device put some unexpected data on the bus */
+	if (priv->done)
+		return size;
+
+	/* wait for the start of frame */
+	if (!priv->num && size && buf[0] != SPS30_SERIAL_SOF_EOF)
+		return 1;
+
+	if (priv->num + size >= ARRAY_SIZE(priv->buf))
+		size = ARRAY_SIZE(priv->buf) - priv->num;
+
+	for (i = 0; i < size; i++) {
+		byte = buf[i];
+		/* remove stuffed bytes on-the-fly */
+		if (byte == SPS30_SERIAL_ESCAPE_CHAR) {
+			priv->escaped = true;
+			continue;
+		}
+
+		byte = sps30_serial_get_byte(priv->escaped, byte);
+		if (priv->escaped && !byte)
+			dev_warn(state->dev, "unrecognized escaped char (0x%02x)\n", byte);
+
+		priv->buf[priv->num++] = byte;
+
+		/* EOF received */
+		if (!priv->escaped && byte == SPS30_SERIAL_SOF_EOF) {
+			if (priv->num < SPS30_SERIAL_FRAME_MIN_SIZE)
+				continue;
+
+			priv->done = true;
+			complete(&priv->new_frame);
+			i++;
+			break;
+		}
+
+		priv->escaped = false;
+	}
+
+	return i;
+}
+
+static const struct serdev_device_ops sps30_serial_device_ops = {
+	.receive_buf = sps30_serial_receive_buf,
+	.write_wakeup = serdev_device_write_wakeup,
+};
+
+static int sps30_serial_start_meas(struct sps30_state *state)
+{
+	/* request BE IEEE754 formatted data */
+	unsigned char buf[] = { 0x01, 0x03 };
+
+	return sps30_serial_command(state, SPS30_SERIAL_START_MEAS, buf, sizeof(buf), NULL, 0);
+}
+
+static int sps30_serial_stop_meas(struct sps30_state *state)
+{
+	return sps30_serial_command(state, SPS30_SERIAL_STOP_MEAS, NULL, 0, NULL, 0);
+}
+
+static int sps30_serial_reset(struct sps30_state *state)
+{
+	int ret;
+
+	ret = sps30_serial_command(state, SPS30_SERIAL_RESET, NULL, 0, NULL, 0);
+	msleep(500);
+
+	return ret;
+}
+
+static int sps30_serial_read_meas(struct sps30_state *state, __be32 *meas, size_t num)
+{
+	int ret;
+
+	/* measurements are ready within a second */
+	if (msleep_interruptible(1000))
+		return -EINTR;
+
+	ret = sps30_serial_command(state, SPS30_SERIAL_READ_MEAS, NULL, 0, meas, num * sizeof(*meas));
+	if (ret < 0)
+		return ret;
+	/* if measurements aren't ready sensor returns empty frame */
+	if (ret == SPS30_SERIAL_FRAME_MIN_SIZE)
+		return -ETIMEDOUT;
+	if (ret != num * sizeof(*meas))
+		return -EIO;
+
+	return 0;
+}
+
+static int sps30_serial_clean_fan(struct sps30_state *state)
+{
+	return sps30_serial_command(state, SPS30_SERIAL_CLEAN_FAN, NULL, 0, NULL, 0);
+}
+
+static int sps30_serial_read_cleaning_period(struct sps30_state *state, __be32 *period)
+{
+	unsigned char buf[] = { 0x00 };
+	int ret;
+
+	ret = sps30_serial_command(state, SPS30_SERIAL_PERIOD, buf, sizeof(buf),
+				   period, sizeof(*period));
+	if (ret < 0)
+		return ret;
+	if (ret != sizeof(*period))
+		return -EIO;
+
+	return 0;
+}
+
+static int sps30_serial_write_cleaning_period(struct sps30_state *state, __be32 period)
+{
+	unsigned char buf[5] = { 0x00 };
+
+	memcpy(buf + 1, &period, sizeof(period));
+
+	return sps30_serial_command(state, SPS30_SERIAL_PERIOD, buf, sizeof(buf), NULL, 0);
+}
+
+static int sps30_serial_show_info(struct sps30_state *state)
+{
+	/*
+	 * tell device do return serial number and add extra nul byte just in case
+	 * serial number isn't a valid string
+	 */
+	unsigned char buf[32 + 1] = { 0x03 };
+	struct device *dev = state->dev;
+	int ret;
+
+	ret = sps30_serial_command(state, SPS30_SERIAL_DEV_INFO, buf, 1, buf, sizeof(buf) - 1);
+	if (ret < 0)
+		return ret;
+	if (ret != sizeof(buf) - 1)
+		return -EIO;
+
+	dev_info(dev, "serial number: %s\n", buf);
+
+	ret = sps30_serial_command(state, SPS30_SERIAL_READ_VERSION, NULL, 0, buf, sizeof(buf) - 1);
+	if (ret < 0)
+		return ret;
+	if (ret < 2)
+		return -EIO;
+
+	dev_info(dev, "fw version: %u.%u\n", buf[0], buf[1]);
+
+	return 0;
+}
+
+static const struct sps30_ops sps30_serial_ops = {
+	.start_meas = sps30_serial_start_meas,
+	.stop_meas = sps30_serial_stop_meas,
+	.read_meas = sps30_serial_read_meas,
+	.reset = sps30_serial_reset,
+	.clean_fan = sps30_serial_clean_fan,
+	.read_cleaning_period = sps30_serial_read_cleaning_period,
+	.write_cleaning_period = sps30_serial_write_cleaning_period,
+	.show_info = sps30_serial_show_info,
+};
+
+static int sps30_serial_probe(struct serdev_device *serdev)
+{
+	struct device *dev = &serdev->dev;
+	struct sps30_serial_priv *priv;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	init_completion(&priv->new_frame);
+	serdev_device_set_client_ops(serdev, &sps30_serial_device_ops);
+
+	ret = devm_serdev_device_open(dev, serdev);
+	if (ret)
+		return ret;
+
+	serdev_device_set_baudrate(serdev, 115200);
+	serdev_device_set_flow_control(serdev, false);
+
+	ret = serdev_device_set_parity(serdev, SERDEV_PARITY_NONE);
+	if (ret)
+		return ret;
+
+	return sps30_probe(dev, SPS30_SERIAL_DEV_NAME, priv, &sps30_serial_ops);
+}
+
+static const struct of_device_id sps30_serial_of_match[] = {
+	{ .compatible = "sensirion,sps30" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, sps30_serial_of_match);
+
+static struct serdev_device_driver sps30_serial_driver = {
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.of_match_table = sps30_serial_of_match,
+	},
+	.probe = sps30_serial_probe,
+};
+module_serdev_device_driver(sps30_serial_driver);
+
+MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
+MODULE_DESCRIPTION("Sensirion SPS30 particulate matter sensor serial driver");
+MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS("IIO_SPS30");
diff --git a/drivers/iio/chemical/sunrise_co2.c b/drivers/iio/chemical/sunrise_co2.c
new file mode 100644
index 000000000..dae8a7025
--- /dev/null
+++ b/drivers/iio/chemical/sunrise_co2.c
@@ -0,0 +1,534 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Senseair Sunrise 006-0-0007 CO2 sensor driver.
+ *
+ * Copyright (C) 2021 Jacopo Mondi
+ *
+ * List of features not yet supported by the driver:
+ * - controllable EN pin
+ * - single-shot operations using the nDRY pin.
+ * - ABC/target calibration
+ */
+
+#include <linux/bitops.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/regmap.h>
+#include <linux/time64.h>
+
+#include <linux/iio/iio.h>
+
+#define DRIVER_NAME "sunrise_co2"
+
+#define SUNRISE_ERROR_STATUS_REG		0x00
+#define SUNRISE_CO2_FILTERED_COMP_REG		0x06
+#define SUNRISE_CHIP_TEMPERATURE_REG		0x08
+#define SUNRISE_CALIBRATION_STATUS_REG		0x81
+#define SUNRISE_CALIBRATION_COMMAND_REG		0x82
+#define SUNRISE_CALIBRATION_FACTORY_CMD		0x7c02
+#define SUNRISE_CALIBRATION_BACKGROUND_CMD	0x7c06
+/*
+ * The calibration timeout is not characterized in the datasheet.
+ * Use 30 seconds as a reasonable upper limit.
+ */
+#define SUNRISE_CALIBRATION_TIMEOUT_US		(30 * USEC_PER_SEC)
+
+struct sunrise_dev {
+	struct i2c_client *client;
+	struct regmap *regmap;
+	/* Protects access to IIO attributes. */
+	struct mutex lock;
+	bool ignore_nak;
+};
+
+/* Custom regmap read/write operations: perform unlocked access to the i2c bus. */
+
+static int sunrise_regmap_read(void *context, const void *reg_buf,
+			       size_t reg_size, void *val_buf, size_t val_size)
+{
+	struct i2c_client *client = context;
+	struct sunrise_dev *sunrise = i2c_get_clientdata(client);
+	union i2c_smbus_data data = { };
+	int ret;
+
+	if (reg_size != 1 || !val_size)
+		return -EINVAL;
+
+	data.block[0] = val_size;
+
+	/*
+	 * Wake up sensor by sending sensor address: START, sensor address,
+	 * STOP. Sensor will not ACK this byte.
+	 *
+	 * The chip enters a low power state after 15ms without
+	 * communications or after a complete read/write sequence.
+	 */
+	__i2c_smbus_xfer(client->adapter, client->addr,
+			 sunrise->ignore_nak ? I2C_M_IGNORE_NAK : 0,
+			 I2C_SMBUS_WRITE, 0, I2C_SMBUS_BYTE_DATA, &data);
+
+	usleep_range(500, 1500);
+
+	ret = __i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+			       I2C_SMBUS_READ, ((u8 *)reg_buf)[0],
+			       I2C_SMBUS_I2C_BLOCK_DATA, &data);
+	if (ret < 0)
+		return ret;
+
+	memcpy(val_buf, &data.block[1], data.block[0]);
+
+	return 0;
+}
+
+static int sunrise_regmap_write(void *context, const void *val_buf, size_t count)
+{
+	struct i2c_client *client = context;
+	struct sunrise_dev *sunrise = i2c_get_clientdata(client);
+	union i2c_smbus_data data = { };
+
+	/* Discard reg address from values count. */
+	if (!count)
+		return -EINVAL;
+	count--;
+
+	data.block[0] = count;
+	memcpy(&data.block[1], (u8 *)val_buf + 1, count);
+
+	__i2c_smbus_xfer(client->adapter, client->addr,
+			 sunrise->ignore_nak ? I2C_M_IGNORE_NAK : 0,
+			 I2C_SMBUS_WRITE, 0, I2C_SMBUS_BYTE_DATA, &data);
+
+	usleep_range(500, 1500);
+
+	return __i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+				I2C_SMBUS_WRITE, ((u8 *)val_buf)[0],
+				I2C_SMBUS_I2C_BLOCK_DATA, &data);
+}
+
+/*
+ * Sunrise i2c read/write operations: lock the i2c segment to avoid losing the
+ * wake up session. Use custom regmap operations that perform unlocked access to
+ * the i2c bus.
+ */
+static int sunrise_read_byte(struct sunrise_dev *sunrise, u8 reg)
+{
+	const struct i2c_client *client = sunrise->client;
+	const struct device *dev = &client->dev;
+	unsigned int val;
+	int ret;
+
+	i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
+	ret = regmap_read(sunrise->regmap, reg, &val);
+	i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
+	if (ret) {
+		dev_err(dev, "Read byte failed: reg 0x%02x (%d)\n", reg, ret);
+		return ret;
+	}
+
+	return val;
+}
+
+static int sunrise_read_word(struct sunrise_dev *sunrise, u8 reg, u16 *val)
+{
+	const struct i2c_client *client = sunrise->client;
+	const struct device *dev = &client->dev;
+	__be16 be_val;
+	int ret;
+
+	i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
+	ret = regmap_bulk_read(sunrise->regmap, reg, &be_val, sizeof(be_val));
+	i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
+	if (ret) {
+		dev_err(dev, "Read word failed: reg 0x%02x (%d)\n", reg, ret);
+		return ret;
+	}
+
+	*val = be16_to_cpu(be_val);
+
+	return 0;
+}
+
+static int sunrise_write_byte(struct sunrise_dev *sunrise, u8 reg, u8 val)
+{
+	const struct i2c_client *client = sunrise->client;
+	const struct device *dev = &client->dev;
+	int ret;
+
+	i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
+	ret = regmap_write(sunrise->regmap, reg, val);
+	i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
+	if (ret)
+		dev_err(dev, "Write byte failed: reg 0x%02x (%d)\n", reg, ret);
+
+	return ret;
+}
+
+static int sunrise_write_word(struct sunrise_dev *sunrise, u8 reg, u16 data)
+{
+	const struct i2c_client *client = sunrise->client;
+	const struct device *dev = &client->dev;
+	__be16 be_data = cpu_to_be16(data);
+	int ret;
+
+	i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
+	ret = regmap_bulk_write(sunrise->regmap, reg, &be_data, sizeof(be_data));
+	i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
+	if (ret)
+		dev_err(dev, "Write word failed: reg 0x%02x (%d)\n", reg, ret);
+
+	return ret;
+}
+
+/* Trigger a calibration cycle. */
+
+enum {
+	SUNRISE_CALIBRATION_FACTORY,
+	SUNRISE_CALIBRATION_BACKGROUND,
+};
+
+static const struct sunrise_calib_data {
+	u16 cmd;
+	u8 bit;
+	const char * const name;
+} calib_data[] = {
+	[SUNRISE_CALIBRATION_FACTORY] = {
+		SUNRISE_CALIBRATION_FACTORY_CMD,
+		BIT(2),
+		"factory_calibration",
+	},
+	[SUNRISE_CALIBRATION_BACKGROUND] = {
+		SUNRISE_CALIBRATION_BACKGROUND_CMD,
+		BIT(5),
+		"background_calibration",
+	},
+};
+
+static int sunrise_calibrate(struct sunrise_dev *sunrise,
+			     const struct sunrise_calib_data *data)
+{
+	unsigned int status;
+	int ret;
+
+	/* Reset the calibration status reg. */
+	ret = sunrise_write_byte(sunrise, SUNRISE_CALIBRATION_STATUS_REG, 0x00);
+	if (ret)
+		return ret;
+
+	/* Write a calibration command and poll the calibration status bit. */
+	ret = sunrise_write_word(sunrise, SUNRISE_CALIBRATION_COMMAND_REG, data->cmd);
+	if (ret)
+		return ret;
+
+	dev_dbg(&sunrise->client->dev, "%s in progress\n", data->name);
+
+	/*
+	 * Calibration takes several seconds, so the sleep time between reads
+	 * can be pretty relaxed.
+	 */
+	return read_poll_timeout(sunrise_read_byte, status, status & data->bit,
+				 200000, SUNRISE_CALIBRATION_TIMEOUT_US, false,
+				 sunrise, SUNRISE_CALIBRATION_STATUS_REG);
+}
+
+static ssize_t sunrise_cal_factory_write(struct iio_dev *iiodev,
+					 uintptr_t private,
+					 const struct iio_chan_spec *chan,
+					 const char *buf, size_t len)
+{
+	struct sunrise_dev *sunrise = iio_priv(iiodev);
+	bool enable;
+	int ret;
+
+	ret = kstrtobool(buf, &enable);
+	if (ret)
+		return ret;
+
+	if (!enable)
+		return len;
+
+	mutex_lock(&sunrise->lock);
+	ret = sunrise_calibrate(sunrise, &calib_data[SUNRISE_CALIBRATION_FACTORY]);
+	mutex_unlock(&sunrise->lock);
+	if (ret)
+		return ret;
+
+	return len;
+}
+
+static ssize_t sunrise_cal_background_write(struct iio_dev *iiodev,
+					    uintptr_t private,
+					    const struct iio_chan_spec *chan,
+					    const char *buf, size_t len)
+{
+	struct sunrise_dev *sunrise = iio_priv(iiodev);
+	bool enable;
+	int ret;
+
+	ret = kstrtobool(buf, &enable);
+	if (ret)
+		return ret;
+
+	if (!enable)
+		return len;
+
+	mutex_lock(&sunrise->lock);
+	ret = sunrise_calibrate(sunrise, &calib_data[SUNRISE_CALIBRATION_BACKGROUND]);
+	mutex_unlock(&sunrise->lock);
+	if (ret)
+		return ret;
+
+	return len;
+}
+
+ /* Enumerate and retrieve the chip error status. */
+enum {
+	SUNRISE_ERROR_FATAL,
+	SUNRISE_ERROR_I2C,
+	SUNRISE_ERROR_ALGORITHM,
+	SUNRISE_ERROR_CALIBRATION,
+	SUNRISE_ERROR_SELF_DIAGNOSTIC,
+	SUNRISE_ERROR_OUT_OF_RANGE,
+	SUNRISE_ERROR_MEMORY,
+	SUNRISE_ERROR_NO_MEASUREMENT,
+	SUNRISE_ERROR_LOW_VOLTAGE,
+	SUNRISE_ERROR_MEASUREMENT_TIMEOUT,
+};
+
+static const char * const sunrise_error_statuses[] = {
+	[SUNRISE_ERROR_FATAL] = "error_fatal",
+	[SUNRISE_ERROR_I2C] = "error_i2c",
+	[SUNRISE_ERROR_ALGORITHM] = "error_algorithm",
+	[SUNRISE_ERROR_CALIBRATION] = "error_calibration",
+	[SUNRISE_ERROR_SELF_DIAGNOSTIC] = "error_self_diagnostic",
+	[SUNRISE_ERROR_OUT_OF_RANGE] = "error_out_of_range",
+	[SUNRISE_ERROR_MEMORY] = "error_memory",
+	[SUNRISE_ERROR_NO_MEASUREMENT] = "error_no_measurement",
+	[SUNRISE_ERROR_LOW_VOLTAGE] = "error_low_voltage",
+	[SUNRISE_ERROR_MEASUREMENT_TIMEOUT] = "error_measurement_timeout",
+};
+
+static const struct iio_enum sunrise_error_statuses_enum = {
+	.items = sunrise_error_statuses,
+	.num_items = ARRAY_SIZE(sunrise_error_statuses),
+};
+
+static ssize_t sunrise_error_status_read(struct iio_dev *iiodev,
+					 uintptr_t private,
+					 const struct iio_chan_spec *chan,
+					 char *buf)
+{
+	struct sunrise_dev *sunrise = iio_priv(iiodev);
+	unsigned long errors;
+	ssize_t len = 0;
+	u16 value;
+	int ret;
+	u8 i;
+
+	mutex_lock(&sunrise->lock);
+	ret = sunrise_read_word(sunrise, SUNRISE_ERROR_STATUS_REG, &value);
+	if (ret) {
+		mutex_unlock(&sunrise->lock);
+		return ret;
+	}
+
+	errors = value;
+	for_each_set_bit(i, &errors, ARRAY_SIZE(sunrise_error_statuses))
+		len += sysfs_emit_at(buf, len, "%s ", sunrise_error_statuses[i]);
+
+	if (len)
+		buf[len - 1] = '\n';
+
+	mutex_unlock(&sunrise->lock);
+
+	return len;
+}
+
+static const struct iio_chan_spec_ext_info sunrise_concentration_ext_info[] = {
+	/* Calibration triggers. */
+	{
+		.name = "calibration_factory",
+		.write = sunrise_cal_factory_write,
+		.shared = IIO_SEPARATE,
+	},
+	{
+		.name = "calibration_background",
+		.write = sunrise_cal_background_write,
+		.shared = IIO_SEPARATE,
+	},
+
+	/* Error statuses. */
+	{
+		.name = "error_status",
+		.read = sunrise_error_status_read,
+		.shared = IIO_SHARED_BY_ALL,
+	},
+	{
+		.name = "error_status_available",
+		.shared = IIO_SHARED_BY_ALL,
+		.read = iio_enum_available_read,
+		.private = (uintptr_t)&sunrise_error_statuses_enum,
+	},
+	{ }
+};
+
+static const struct iio_chan_spec sunrise_channels[] = {
+	{
+		.type = IIO_CONCENTRATION,
+		.modified = 1,
+		.channel2 = IIO_MOD_CO2,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE),
+		.ext_info = sunrise_concentration_ext_info,
+	},
+	{
+		.type = IIO_TEMP,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE),
+	},
+};
+
+static int sunrise_read_raw(struct iio_dev *iio_dev,
+			    const struct iio_chan_spec *chan,
+			    int *val, int *val2, long mask)
+{
+	struct sunrise_dev *sunrise = iio_priv(iio_dev);
+	u16 value;
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		switch (chan->type) {
+		case IIO_CONCENTRATION:
+			mutex_lock(&sunrise->lock);
+			ret = sunrise_read_word(sunrise, SUNRISE_CO2_FILTERED_COMP_REG,
+						&value);
+			mutex_unlock(&sunrise->lock);
+
+			if (ret)
+				return ret;
+
+			*val = value;
+			return IIO_VAL_INT;
+
+		case IIO_TEMP:
+			mutex_lock(&sunrise->lock);
+			ret = sunrise_read_word(sunrise, SUNRISE_CHIP_TEMPERATURE_REG,
+						&value);
+			mutex_unlock(&sunrise->lock);
+
+			if (ret)
+				return ret;
+
+			*val = value;
+			return IIO_VAL_INT;
+
+		default:
+			return -EINVAL;
+		}
+
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_CONCENTRATION:
+			/*
+			 * 1 / 10^4 to comply with IIO scale for CO2
+			 * (percentage). The chip CO2 reading range is [400 -
+			 * 5000] ppm which corresponds to [0,004 - 0,5] %.
+			 */
+			*val = 1;
+			*val2 = 10000;
+			return IIO_VAL_FRACTIONAL;
+
+		case IIO_TEMP:
+			/* x10 to comply with IIO scale (millidegrees celsius). */
+			*val = 10;
+			return IIO_VAL_INT;
+
+		default:
+			return -EINVAL;
+		}
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info sunrise_info = {
+	.read_raw = sunrise_read_raw,
+};
+
+static const struct regmap_bus sunrise_regmap_bus = {
+	.read = sunrise_regmap_read,
+	.write = sunrise_regmap_write,
+};
+
+static const struct regmap_config sunrise_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static int sunrise_probe(struct i2c_client *client)
+{
+	struct sunrise_dev *sunrise;
+	struct iio_dev *iio_dev;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
+						      I2C_FUNC_SMBUS_BLOCK_DATA)) {
+		dev_err(&client->dev,
+			"Adapter does not support required functionalities\n");
+		return -EOPNOTSUPP;
+	}
+
+	iio_dev = devm_iio_device_alloc(&client->dev, sizeof(*sunrise));
+	if (!iio_dev)
+		return -ENOMEM;
+
+	sunrise = iio_priv(iio_dev);
+	sunrise->client = client;
+	mutex_init(&sunrise->lock);
+
+	i2c_set_clientdata(client, sunrise);
+
+	sunrise->regmap = devm_regmap_init(&client->dev, &sunrise_regmap_bus,
+					   client, &sunrise_regmap_config);
+	if (IS_ERR(sunrise->regmap)) {
+		dev_err(&client->dev, "Failed to initialize regmap\n");
+		return PTR_ERR(sunrise->regmap);
+	}
+
+	/*
+	 * The chip nacks the wake up message. If the adapter does not support
+	 * protocol mangling do not set the I2C_M_IGNORE_NAK flag at the expense
+	 * of possible cruft in the logs.
+	 */
+	if (i2c_check_functionality(client->adapter, I2C_FUNC_PROTOCOL_MANGLING))
+		sunrise->ignore_nak = true;
+
+	iio_dev->info = &sunrise_info;
+	iio_dev->name = DRIVER_NAME;
+	iio_dev->channels = sunrise_channels;
+	iio_dev->num_channels = ARRAY_SIZE(sunrise_channels);
+	iio_dev->modes = INDIO_DIRECT_MODE;
+
+	return devm_iio_device_register(&client->dev, iio_dev);
+}
+
+static const struct of_device_id sunrise_of_match[] = {
+	{ .compatible = "senseair,sunrise-006-0-0007" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, sunrise_of_match);
+
+static struct i2c_driver sunrise_driver = {
+	.driver = {
+		.name = DRIVER_NAME,
+		.of_match_table = sunrise_of_match,
+	},
+	.probe = sunrise_probe,
+};
+module_i2c_driver(sunrise_driver);
+
+MODULE_AUTHOR("Jacopo Mondi <jacopo@jmondi.org>");
+MODULE_DESCRIPTION("Senseair Sunrise 006-0-0007 CO2 sensor IIO driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/chemical/vz89x.c b/drivers/iio/chemical/vz89x.c
new file mode 100644
index 000000000..2e10a6b17
--- /dev/null
+++ b/drivers/iio/chemical/vz89x.c
@@ -0,0 +1,405 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * vz89x.c - Support for SGX Sensortech MiCS VZ89X VOC sensors
+ *
+ * Copyright (C) 2015-2018
+ * Author: Matt Ranostay <matt.ranostay@konsulko.com>
+ */
+
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define VZ89X_REG_MEASUREMENT		0x09
+#define VZ89X_REG_MEASUREMENT_RD_SIZE	6
+#define VZ89X_REG_MEASUREMENT_WR_SIZE	3
+
+#define VZ89X_VOC_CO2_IDX		0
+#define VZ89X_VOC_SHORT_IDX		1
+#define VZ89X_VOC_TVOC_IDX		2
+#define VZ89X_VOC_RESISTANCE_IDX	3
+
+#define VZ89TE_REG_MEASUREMENT		0x0c
+#define VZ89TE_REG_MEASUREMENT_RD_SIZE	7
+#define VZ89TE_REG_MEASUREMENT_WR_SIZE	6
+
+#define VZ89TE_VOC_TVOC_IDX		0
+#define VZ89TE_VOC_CO2_IDX		1
+#define VZ89TE_VOC_RESISTANCE_IDX	2
+
+enum {
+	VZ89X,
+	VZ89TE,
+};
+
+struct vz89x_chip_data;
+
+struct vz89x_data {
+	struct i2c_client *client;
+	const struct vz89x_chip_data *chip;
+	struct mutex lock;
+	int (*xfer)(struct vz89x_data *data, u8 cmd);
+
+	bool is_valid;
+	unsigned long last_update;
+	u8 buffer[VZ89TE_REG_MEASUREMENT_RD_SIZE];
+};
+
+struct vz89x_chip_data {
+	bool (*valid)(struct vz89x_data *data);
+	const struct iio_chan_spec *channels;
+	u8 num_channels;
+
+	u8 cmd;
+	u8 read_size;
+	u8 write_size;
+};
+
+static const struct iio_chan_spec vz89x_channels[] = {
+	{
+		.type = IIO_CONCENTRATION,
+		.channel2 = IIO_MOD_CO2,
+		.modified = 1,
+		.info_mask_separate =
+			BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_RAW),
+		.address = VZ89X_VOC_CO2_IDX,
+	},
+	{
+		.type = IIO_CONCENTRATION,
+		.channel2 = IIO_MOD_VOC,
+		.modified = 1,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.address = VZ89X_VOC_SHORT_IDX,
+		.extend_name = "short",
+	},
+	{
+		.type = IIO_CONCENTRATION,
+		.channel2 = IIO_MOD_VOC,
+		.modified = 1,
+		.info_mask_separate =
+			BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_RAW),
+		.address = VZ89X_VOC_TVOC_IDX,
+	},
+	{
+		.type = IIO_RESISTANCE,
+		.info_mask_separate =
+			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+		.address = VZ89X_VOC_RESISTANCE_IDX,
+		.scan_index = -1,
+		.scan_type = {
+			.endianness = IIO_LE,
+		},
+	},
+};
+
+static const struct iio_chan_spec vz89te_channels[] = {
+	{
+		.type = IIO_CONCENTRATION,
+		.channel2 = IIO_MOD_VOC,
+		.modified = 1,
+		.info_mask_separate =
+			BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_RAW),
+		.address = VZ89TE_VOC_TVOC_IDX,
+	},
+
+	{
+		.type = IIO_CONCENTRATION,
+		.channel2 = IIO_MOD_CO2,
+		.modified = 1,
+		.info_mask_separate =
+			BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_RAW),
+		.address = VZ89TE_VOC_CO2_IDX,
+	},
+	{
+		.type = IIO_RESISTANCE,
+		.info_mask_separate =
+			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+		.address = VZ89TE_VOC_RESISTANCE_IDX,
+		.scan_index = -1,
+		.scan_type = {
+			.endianness = IIO_BE,
+		},
+	},
+};
+
+static IIO_CONST_ATTR(in_concentration_co2_scale, "0.00000698689");
+static IIO_CONST_ATTR(in_concentration_voc_scale, "0.00000000436681223");
+
+static struct attribute *vz89x_attributes[] = {
+	&iio_const_attr_in_concentration_co2_scale.dev_attr.attr,
+	&iio_const_attr_in_concentration_voc_scale.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group vz89x_attrs_group = {
+	.attrs = vz89x_attributes,
+};
+
+/*
+ * Chipset sometime updates in the middle of a reading causing it to reset the
+ * data pointer, and causing invalid reading of previous data.
+ * We can check for this by reading MSB of the resistance reading that is
+ * always zero, and by also confirming the VOC_short isn't zero.
+ */
+
+static bool vz89x_measurement_is_valid(struct vz89x_data *data)
+{
+	if (data->buffer[VZ89X_VOC_SHORT_IDX] == 0)
+		return true;
+
+	return !!(data->buffer[data->chip->read_size - 1] > 0);
+}
+
+/* VZ89TE device has a modified CRC-8 two complement check */
+static bool vz89te_measurement_is_valid(struct vz89x_data *data)
+{
+	u8 crc = 0;
+	int i, sum = 0;
+
+	for (i = 0; i < (data->chip->read_size - 1); i++) {
+		sum = crc + data->buffer[i];
+		crc = sum;
+		crc += sum / 256;
+	}
+
+	return !((0xff - crc) == data->buffer[data->chip->read_size - 1]);
+}
+
+static int vz89x_i2c_xfer(struct vz89x_data *data, u8 cmd)
+{
+	const struct vz89x_chip_data *chip = data->chip;
+	struct i2c_client *client = data->client;
+	struct i2c_msg msg[2];
+	int ret;
+	u8 buf[6] = { cmd, 0, 0, 0, 0, 0xf3 };
+
+	msg[0].addr = client->addr;
+	msg[0].flags = client->flags;
+	msg[0].len = chip->write_size;
+	msg[0].buf  = (char *) &buf;
+
+	msg[1].addr = client->addr;
+	msg[1].flags = client->flags | I2C_M_RD;
+	msg[1].len = chip->read_size;
+	msg[1].buf = (char *) &data->buffer;
+
+	ret = i2c_transfer(client->adapter, msg, 2);
+
+	return (ret == 2) ? 0 : ret;
+}
+
+static int vz89x_smbus_xfer(struct vz89x_data *data, u8 cmd)
+{
+	struct i2c_client *client = data->client;
+	int ret;
+	int i;
+
+	ret = i2c_smbus_write_word_data(client, cmd, 0);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < data->chip->read_size; i++) {
+		ret = i2c_smbus_read_byte(client);
+		if (ret < 0)
+			return ret;
+		data->buffer[i] = ret;
+	}
+
+	return 0;
+}
+
+static int vz89x_get_measurement(struct vz89x_data *data)
+{
+	const struct vz89x_chip_data *chip = data->chip;
+	int ret;
+
+	/* sensor can only be polled once a second max per datasheet */
+	if (!time_after(jiffies, data->last_update + HZ))
+		return data->is_valid ? 0 : -EAGAIN;
+
+	data->is_valid = false;
+	data->last_update = jiffies;
+
+	ret = data->xfer(data, chip->cmd);
+	if (ret < 0)
+		return ret;
+
+	ret = chip->valid(data);
+	if (ret)
+		return -EAGAIN;
+
+	data->is_valid = true;
+
+	return 0;
+}
+
+static int vz89x_get_resistance_reading(struct vz89x_data *data,
+					struct iio_chan_spec const *chan,
+					int *val)
+{
+	u8 *tmp = &data->buffer[chan->address];
+
+	switch (chan->scan_type.endianness) {
+	case IIO_LE:
+		*val = le32_to_cpup((__le32 *) tmp) & GENMASK(23, 0);
+		break;
+	case IIO_BE:
+		*val = be32_to_cpup((__be32 *) tmp) >> 8;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int vz89x_read_raw(struct iio_dev *indio_dev,
+			  struct iio_chan_spec const *chan, int *val,
+			  int *val2, long mask)
+{
+	struct vz89x_data *data = iio_priv(indio_dev);
+	int ret = -EINVAL;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&data->lock);
+		ret = vz89x_get_measurement(data);
+		mutex_unlock(&data->lock);
+
+		if (ret)
+			return ret;
+
+		switch (chan->type) {
+		case IIO_CONCENTRATION:
+			*val = data->buffer[chan->address];
+			return IIO_VAL_INT;
+		case IIO_RESISTANCE:
+			ret = vz89x_get_resistance_reading(data, chan, val);
+			if (!ret)
+				return IIO_VAL_INT;
+			break;
+		default:
+			return -EINVAL;
+		}
+		break;
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_RESISTANCE:
+			*val = 10;
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+		break;
+	case IIO_CHAN_INFO_OFFSET:
+		switch (chan->channel2) {
+		case IIO_MOD_CO2:
+			*val = 44;
+			*val2 = 250000;
+			return IIO_VAL_INT_PLUS_MICRO;
+		case IIO_MOD_VOC:
+			*val = -13;
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	return ret;
+}
+
+static const struct iio_info vz89x_info = {
+	.attrs		= &vz89x_attrs_group,
+	.read_raw	= vz89x_read_raw,
+};
+
+static const struct vz89x_chip_data vz89x_chips[] = {
+	{
+		.valid = vz89x_measurement_is_valid,
+
+		.cmd = VZ89X_REG_MEASUREMENT,
+		.read_size = VZ89X_REG_MEASUREMENT_RD_SIZE,
+		.write_size = VZ89X_REG_MEASUREMENT_WR_SIZE,
+
+		.channels = vz89x_channels,
+		.num_channels = ARRAY_SIZE(vz89x_channels),
+	},
+	{
+		.valid = vz89te_measurement_is_valid,
+
+		.cmd = VZ89TE_REG_MEASUREMENT,
+		.read_size = VZ89TE_REG_MEASUREMENT_RD_SIZE,
+		.write_size = VZ89TE_REG_MEASUREMENT_WR_SIZE,
+
+		.channels = vz89te_channels,
+		.num_channels = ARRAY_SIZE(vz89te_channels),
+	},
+};
+
+static const struct of_device_id vz89x_dt_ids[] = {
+	{ .compatible = "sgx,vz89x", .data = &vz89x_chips[VZ89X] },
+	{ .compatible = "sgx,vz89te", .data = &vz89x_chips[VZ89TE] },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, vz89x_dt_ids);
+
+static int vz89x_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct iio_dev *indio_dev;
+	struct vz89x_data *data;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+	data = iio_priv(indio_dev);
+
+	if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+		data->xfer = vz89x_i2c_xfer;
+	else if (i2c_check_functionality(client->adapter,
+				I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE))
+		data->xfer = vz89x_smbus_xfer;
+	else
+		return -EOPNOTSUPP;
+
+	data->chip = i2c_get_match_data(client);
+
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;
+	data->last_update = jiffies - HZ;
+	mutex_init(&data->lock);
+
+	indio_dev->info = &vz89x_info;
+	indio_dev->name = dev_name(dev);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	indio_dev->channels = data->chip->channels;
+	indio_dev->num_channels = data->chip->num_channels;
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct i2c_device_id vz89x_id[] = {
+	{ .name = "vz89x", .driver_data = (kernel_ulong_t)&vz89x_chips[VZ89X] },
+	{ .name = "vz89te", .driver_data = (kernel_ulong_t)&vz89x_chips[VZ89TE] },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, vz89x_id);
+
+static struct i2c_driver vz89x_driver = {
+	.driver = {
+		.name	= "vz89x",
+		.of_match_table = vz89x_dt_ids,
+	},
+	.probe = vz89x_probe,
+	.id_table = vz89x_id,
+};
+module_i2c_driver(vz89x_driver);
+
+MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
+MODULE_DESCRIPTION("SGX Sensortech MiCS VZ89X VOC sensors");
+MODULE_LICENSE("GPL v2");