Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

10 files changed, 3182 insertions, 0 deletions

diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig
new file mode 100644
index 000000000..b8e005be4
--- /dev/null
+++ b/drivers/iio/chemical/Kconfig
@@ -0,0 +1,72 @@
+#
+# Chemical sensors
+#
+
+menu "Chemical Sensors"
+
+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 BME680
+	tristate "Bosch Sensortec BME680 sensor driver"
+	depends on (I2C || SPI)
+	select REGMAP
+	select BME680_I2C if I2C
+	select BME680_SPI if SPI
+	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 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 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..2f4c4ba4d
--- /dev/null
+++ b/drivers/iio/chemical/Makefile
@@ -0,0 +1,12 @@
+#
+# Makefile for IIO chemical sensors
+#
+
+# When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_ATLAS_PH_SENSOR)	+= atlas-ph-sensor.o
+obj-$(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_IAQCORE)		+= ams-iaq-core.o
+obj-$(CONFIG_VZ89X)		+= vz89x.o
diff --git a/drivers/iio/chemical/ams-iaq-core.c b/drivers/iio/chemical/ams-iaq-core.c
new file mode 100644
index 000000000..a0646ba2a
--- /dev/null
+++ b/drivers/iio/chemical/ams-iaq-core.c
@@ -0,0 +1,190 @@
+// 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;
+} __attribute__((__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,
+			     const struct i2c_device_id *id)
+{
+	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->dev.parent = &client->dev;
+	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[] = {
+	{ "ams-iaq-core", 0 },
+	{ }
+};
+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 = of_match_ptr(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-ph-sensor.c b/drivers/iio/chemical/atlas-ph-sensor.c
new file mode 100644
index 000000000..3a20cb5d9
--- /dev/null
+++ b/drivers/iio/chemical/atlas-ph-sensor.c
@@ -0,0 +1,685 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * atlas-ph-sensor.c - Support for Atlas Scientific OEM pH-SM sensor
+ *
+ * Copyright (C) 2015-2018 Matt Ranostay
+ * 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/irq_work.h>
+#include <linux/gpio.h>
+#include <linux/i2c.h>
+#include <linux/of_device.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_REGMAP_NAME	"atlas_ph_regmap"
+#define ATLAS_DRV_NAME		"atlas_ph"
+
+#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_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_PH_INT_TIME_IN_MS		450
+#define ATLAS_EC_INT_TIME_IN_MS		650
+#define ATLAS_ORP_INT_TIME_IN_MS	450
+
+enum {
+	ATLAS_PH_SM,
+	ATLAS_EC_SM,
+	ATLAS_ORP_SM,
+};
+
+struct atlas_data {
+	struct i2c_client *client;
+	struct iio_trigger *trig;
+	struct atlas_device *chip;
+	struct regmap *regmap;
+	struct irq_work work;
+
+	__be32 buffer[6]; /* 96-bit data + 32-bit pad + 64-bit timestamp */
+};
+
+static const struct regmap_config atlas_regmap_config = {
+	.name = ATLAS_REGMAP_NAME,
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+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_EC_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_EC_CHANNEL(0, ATLAS_REG_TDS_DATA),
+	ATLAS_EC_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 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;
+};
+
+struct atlas_device {
+	const struct iio_chan_spec *channels;
+	int num_channels;
+	int data_reg;
+
+	int (*calibration)(struct atlas_data *data);
+	int delay;
+};
+
+static 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,
+	},
+};
+
+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)
+{
+	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 = iio_triggered_buffer_postenable(indio_dev);
+	if (ret)
+		return ret;
+
+	ret = pm_runtime_get_sync(&data->client->dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(&data->client->dev);
+		return ret;
+	}
+
+	return atlas_set_interrupt(data, true);
+}
+
+static int atlas_buffer_predisable(struct iio_dev *indio_dev)
+{
+	struct atlas_data *data = iio_priv(indio_dev);
+	int ret;
+
+	ret = iio_triggered_buffer_predisable(indio_dev);
+	if (ret)
+		return ret;
+
+	ret = atlas_set_interrupt(data, false);
+	if (ret)
+		return ret;
+
+	pm_runtime_mark_last_busy(&data->client->dev);
+	return pm_runtime_put_autosuspend(&data->client->dev);
+}
+
+static const struct iio_trigger_ops atlas_interrupt_trigger_ops = {
+};
+
+static const struct iio_buffer_setup_ops atlas_buffer_setup_ops = {
+	.postenable = atlas_buffer_postenable,
+	.predisable = atlas_buffer_predisable,
+};
+
+static void atlas_work_handler(struct irq_work *work)
+{
+	struct atlas_data *data = container_of(work, struct atlas_data, work);
+
+	iio_trigger_poll(data->trig);
+}
+
+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 ret;
+
+	ret = regmap_bulk_read(data->regmap, data->chip->data_reg,
+			      (u8 *) &data->buffer,
+			      sizeof(__be32) * (data->chip->num_channels - 2));
+
+	if (!ret)
+		iio_push_to_buffers_with_timestamp(indio_dev, 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);
+
+	irq_work_queue(&data->work);
+
+	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_get_sync(dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(dev);
+		return ret;
+	}
+
+	if (suspended)
+		msleep(data->chip->delay);
+
+	ret = regmap_bulk_read(data->regmap, reg, (u8 *) val, sizeof(*val));
+
+	pm_runtime_mark_last_busy(dev);
+	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_RAW: {
+		int ret;
+		__be32 reg;
+
+		switch (chan->type) {
+		case IIO_TEMP:
+			ret = regmap_bulk_read(data->regmap, chan->address,
+					      (u8 *) &reg, sizeof(reg));
+			break;
+		case IIO_PH:
+		case IIO_CONCENTRATION:
+		case IIO_ELECTRICALCONDUCTIVITY:
+		case IIO_VOLTAGE:
+			ret = iio_device_claim_direct_mode(indio_dev);
+			if (ret)
+				return ret;
+
+			ret = atlas_read_measurement(data, chan->address, &reg);
+
+			iio_device_release_direct_mode(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[] = {
+	{ "atlas-ph-sm", ATLAS_PH_SM},
+	{ "atlas-ec-sm", ATLAS_EC_SM},
+	{ "atlas-orp-sm", ATLAS_ORP_SM},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, atlas_id);
+
+static const struct of_device_id atlas_dt_ids[] = {
+	{ .compatible = "atlas,ph-sm", .data = (void *)ATLAS_PH_SM, },
+	{ .compatible = "atlas,ec-sm", .data = (void *)ATLAS_EC_SM, },
+	{ .compatible = "atlas,orp-sm", .data = (void *)ATLAS_ORP_SM, },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, atlas_dt_ids);
+
+static int atlas_probe(struct i2c_client *client,
+		       const struct i2c_device_id *id)
+{
+	struct atlas_data *data;
+	struct atlas_device *chip;
+	const struct of_device_id *of_id;
+	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;
+
+	of_id = of_match_device(atlas_dt_ids, &client->dev);
+	if (!of_id)
+		chip = &atlas_devices[id->driver_data];
+	else
+		chip = &atlas_devices[(unsigned long)of_id->data];
+
+	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;
+	indio_dev->dev.parent = &client->dev;
+
+	trig = devm_iio_trigger_alloc(&client->dev, "%s-dev%d",
+				      indio_dev->name, indio_dev->id);
+
+	if (!trig)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	data->client = client;
+	data->trig = trig;
+	data->chip = chip;
+	trig->dev.parent = indio_dev->dev.parent;
+	trig->ops = &atlas_interrupt_trigger_ops;
+	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;
+
+	if (client->irq <= 0) {
+		dev_err(&client->dev, "no valid irq defined\n");
+		return -EINVAL;
+	}
+
+	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;
+	}
+
+	init_irq_work(&data->work, atlas_work_handler);
+
+	/* 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_err(&client->dev, "request irq (%d) failed\n", client->irq);
+		goto unregister_buffer;
+	}
+
+	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 int atlas_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct atlas_data *data = iio_priv(indio_dev);
+
+	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);
+	pm_runtime_put_noidle(&client->dev);
+
+	return atlas_set_powermode(data, 0);
+}
+
+#ifdef CONFIG_PM
+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);
+}
+#endif
+
+static const struct dev_pm_ops atlas_pm_ops = {
+	SET_RUNTIME_PM_OPS(atlas_runtime_suspend,
+			   atlas_runtime_resume, NULL)
+};
+
+static struct i2c_driver atlas_driver = {
+	.driver = {
+		.name	= ATLAS_DRV_NAME,
+		.of_match_table	= of_match_ptr(atlas_dt_ids),
+		.pm	= &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 pH-SM sensor");
+MODULE_LICENSE("GPL");
diff --git a/drivers/iio/chemical/bme680.h b/drivers/iio/chemical/bme680.h
new file mode 100644
index 000000000..71dd635fc
--- /dev/null
+++ b/drivers/iio/chemical/bme680.h
@@ -0,0 +1,94 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef BME680_H_
+#define BME680_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 BM6880_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_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_MODE_FORCED			1
+#define BME680_MODE_SLEEP			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_MSK			0x0F
+
+#define BME680_REG_RES_HEAT_RANGE		0x02
+#define BME680_RHRANGE_MSK			0x30
+#define BME680_REG_RES_HEAT_VAL			0x00
+#define BME680_REG_RANGE_SW_ERR			0x04
+#define BME680_RSERROR_MSK			0xF0
+#define BME680_REG_RES_HEAT_0			0x5A
+#define BME680_REG_GAS_WAIT_0			0x64
+#define BME680_GAS_RANGE_MASK			0x0F
+#define BME680_ADC_GAS_RES_SHIFT		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_RUN_GAS_EN_BIT		BIT(4)
+#define     BME680_NB_CONV_0_VAL		0
+
+#define BME680_REG_MEAS_STAT_0			0x1D
+#define   BME680_GAS_MEAS_BIT			BIT(6)
+
+/* Calibration Parameters */
+#define BME680_T2_LSB_REG	0x8A
+#define BME680_T3_REG		0x8C
+#define BME680_P1_LSB_REG	0x8E
+#define BME680_P2_LSB_REG	0x90
+#define BME680_P3_REG		0x92
+#define BME680_P4_LSB_REG	0x94
+#define BME680_P5_LSB_REG	0x96
+#define BME680_P7_REG		0x98
+#define BME680_P6_REG		0x99
+#define BME680_P8_LSB_REG	0x9C
+#define BME680_P9_LSB_REG	0x9E
+#define BME680_P10_REG		0xA0
+#define BME680_H2_LSB_REG	0xE2
+#define BME680_H2_MSB_REG	0xE1
+#define BME680_H1_MSB_REG	0xE3
+#define BME680_H1_LSB_REG	0xE2
+#define BME680_H3_REG		0xE4
+#define BME680_H4_REG		0xE5
+#define BME680_H5_REG		0xE6
+#define BME680_H6_REG		0xE7
+#define BME680_H7_REG		0xE8
+#define BME680_T1_LSB_REG	0xE9
+#define BME680_GH2_LSB_REG	0xEB
+#define BME680_GH1_REG		0xED
+#define BME680_GH3_REG		0xEE
+
+extern const struct regmap_config bme680_regmap_config;
+
+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..b2db59812
--- /dev/null
+++ b/drivers/iio/chemical/bme680_core.c
@@ -0,0 +1,995 @@
+// 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/acpi.h>
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/log2.h>
+#include <linux/regmap.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#include "bme680.h"
+
+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;
+	s8  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;
+};
+
+struct bme680_data {
+	struct regmap *regmap;
+	struct bme680_calib bme680;
+	u8 oversampling_temp;
+	u8 oversampling_press;
+	u8 oversampling_humid;
+	u16 heater_dur;
+	u16 heater_temp;
+	/*
+	 * Carryover value from temperature conversion, used in pressure
+	 * and humidity compensation calculations.
+	 */
+	s32 t_fine;
+};
+
+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_RBTREE,
+};
+EXPORT_SYMBOL(bme680_regmap_config);
+
+static const struct iio_chan_spec bme680_channels[] = {
+	{
+		.type = IIO_TEMP,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+	},
+	{
+		.type = IIO_PRESSURE,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+	},
+	{
+		.type = IIO_HUMIDITYRELATIVE,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+	},
+	{
+		.type = IIO_RESISTANCE,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+	},
+};
+
+static const int bme680_oversampling_avail[] = { 1, 2, 4, 8, 16 };
+
+static int bme680_read_calib(struct bme680_data *data,
+			     struct bme680_calib *calib)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	unsigned int tmp, tmp_msb, tmp_lsb;
+	int ret;
+	__le16 buf;
+
+	/* Temperature related coefficients */
+	ret = regmap_bulk_read(data->regmap, BME680_T1_LSB_REG,
+			       (u8 *) &buf, 2);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_T1_LSB_REG\n");
+		return ret;
+	}
+	calib->par_t1 = le16_to_cpu(buf);
+
+	ret = regmap_bulk_read(data->regmap, BME680_T2_LSB_REG,
+			       (u8 *) &buf, 2);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_T2_LSB_REG\n");
+		return ret;
+	}
+	calib->par_t2 = le16_to_cpu(buf);
+
+	ret = regmap_read(data->regmap, BME680_T3_REG, &tmp);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_T3_REG\n");
+		return ret;
+	}
+	calib->par_t3 = tmp;
+
+	/* Pressure related coefficients */
+	ret = regmap_bulk_read(data->regmap, BME680_P1_LSB_REG,
+			       (u8 *) &buf, 2);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_P1_LSB_REG\n");
+		return ret;
+	}
+	calib->par_p1 = le16_to_cpu(buf);
+
+	ret = regmap_bulk_read(data->regmap, BME680_P2_LSB_REG,
+			       (u8 *) &buf, 2);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_P2_LSB_REG\n");
+		return ret;
+	}
+	calib->par_p2 = le16_to_cpu(buf);
+
+	ret = regmap_read(data->regmap, BME680_P3_REG, &tmp);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_P3_REG\n");
+		return ret;
+	}
+	calib->par_p3 = tmp;
+
+	ret = regmap_bulk_read(data->regmap, BME680_P4_LSB_REG,
+			       (u8 *) &buf, 2);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_P4_LSB_REG\n");
+		return ret;
+	}
+	calib->par_p4 = le16_to_cpu(buf);
+
+	ret = regmap_bulk_read(data->regmap, BME680_P5_LSB_REG,
+			       (u8 *) &buf, 2);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_P5_LSB_REG\n");
+		return ret;
+	}
+	calib->par_p5 = le16_to_cpu(buf);
+
+	ret = regmap_read(data->regmap, BME680_P6_REG, &tmp);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_P6_REG\n");
+		return ret;
+	}
+	calib->par_p6 = tmp;
+
+	ret = regmap_read(data->regmap, BME680_P7_REG, &tmp);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_P7_REG\n");
+		return ret;
+	}
+	calib->par_p7 = tmp;
+
+	ret = regmap_bulk_read(data->regmap, BME680_P8_LSB_REG,
+			       (u8 *) &buf, 2);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_P8_LSB_REG\n");
+		return ret;
+	}
+	calib->par_p8 = le16_to_cpu(buf);
+
+	ret = regmap_bulk_read(data->regmap, BME680_P9_LSB_REG,
+			       (u8 *) &buf, 2);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_P9_LSB_REG\n");
+		return ret;
+	}
+	calib->par_p9 = le16_to_cpu(buf);
+
+	ret = regmap_read(data->regmap, BME680_P10_REG, &tmp);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_P10_REG\n");
+		return ret;
+	}
+	calib->par_p10 = tmp;
+
+	/* Humidity related coefficients */
+	ret = regmap_read(data->regmap, BME680_H1_MSB_REG, &tmp_msb);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_H1_MSB_REG\n");
+		return ret;
+	}
+
+	ret = regmap_read(data->regmap, BME680_H1_LSB_REG, &tmp_lsb);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_H1_LSB_REG\n");
+		return ret;
+	}
+
+	calib->par_h1 = (tmp_msb << BME680_HUM_REG_SHIFT_VAL) |
+				(tmp_lsb & BME680_BIT_H1_DATA_MSK);
+
+	ret = regmap_read(data->regmap, BME680_H2_MSB_REG, &tmp_msb);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_H2_MSB_REG\n");
+		return ret;
+	}
+
+	ret = regmap_read(data->regmap, BME680_H2_LSB_REG, &tmp_lsb);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_H2_LSB_REG\n");
+		return ret;
+	}
+
+	calib->par_h2 = (tmp_msb << BME680_HUM_REG_SHIFT_VAL) |
+				(tmp_lsb >> BME680_HUM_REG_SHIFT_VAL);
+
+	ret = regmap_read(data->regmap, BME680_H3_REG, &tmp);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_H3_REG\n");
+		return ret;
+	}
+	calib->par_h3 = tmp;
+
+	ret = regmap_read(data->regmap, BME680_H4_REG, &tmp);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_H4_REG\n");
+		return ret;
+	}
+	calib->par_h4 = tmp;
+
+	ret = regmap_read(data->regmap, BME680_H5_REG, &tmp);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_H5_REG\n");
+		return ret;
+	}
+	calib->par_h5 = tmp;
+
+	ret = regmap_read(data->regmap, BME680_H6_REG, &tmp);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_H6_REG\n");
+		return ret;
+	}
+	calib->par_h6 = tmp;
+
+	ret = regmap_read(data->regmap, BME680_H7_REG, &tmp);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_H7_REG\n");
+		return ret;
+	}
+	calib->par_h7 = tmp;
+
+	/* Gas heater related coefficients */
+	ret = regmap_read(data->regmap, BME680_GH1_REG, &tmp);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_GH1_REG\n");
+		return ret;
+	}
+	calib->par_gh1 = tmp;
+
+	ret = regmap_bulk_read(data->regmap, BME680_GH2_LSB_REG,
+			       (u8 *) &buf, 2);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_GH2_LSB_REG\n");
+		return ret;
+	}
+	calib->par_gh2 = le16_to_cpu(buf);
+
+	ret = regmap_read(data->regmap, BME680_GH3_REG, &tmp);
+	if (ret < 0) {
+		dev_err(dev, "failed to read BME680_GH3_REG\n");
+		return ret;
+	}
+	calib->par_gh3 = tmp;
+
+	/* Other coefficients */
+	ret = regmap_read(data->regmap, BME680_REG_RES_HEAT_RANGE, &tmp);
+	if (ret < 0) {
+		dev_err(dev, "failed to read resistance heat range\n");
+		return ret;
+	}
+	calib->res_heat_range = (tmp & BME680_RHRANGE_MSK) / 16;
+
+	ret = regmap_read(data->regmap, BME680_REG_RES_HEAT_VAL, &tmp);
+	if (ret < 0) {
+		dev_err(dev, "failed to read resistance heat value\n");
+		return ret;
+	}
+	calib->res_heat_val = tmp;
+
+	ret = regmap_read(data->regmap, BME680_REG_RANGE_SW_ERR, &tmp);
+	if (ret < 0) {
+		dev_err(dev, "failed to read range software error\n");
+		return ret;
+	}
+	calib->range_sw_err = (tmp & BME680_RSERROR_MSK) / 16;
+
+	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 s16 bme680_compensate_temp(struct bme680_data *data,
+				  s32 adc_temp)
+{
+	struct bme680_calib *calib = &data->bme680;
+	s64 var1, var2, var3;
+	s16 calc_temp;
+
+	/* If the calibration is invalid, attempt to reload it */
+	if (!calib->par_t2)
+		bme680_read_calib(data, calib);
+
+	var1 = (adc_temp >> 3) - (calib->par_t1 << 1);
+	var2 = (var1 * calib->par_t2) >> 11;
+	var3 = ((var1 >> 1) * (var1 >> 1)) >> 12;
+	var3 = (var3 * (calib->par_t3 << 4)) >> 14;
+	data->t_fine = var2 + var3;
+	calc_temp = (data->t_fine * 5 + 128) >> 8;
+
+	return calc_temp;
+}
+
+/*
+ * 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)
+{
+	struct bme680_calib *calib = &data->bme680;
+	s32 var1, var2, var3, press_comp;
+
+	var1 = (data->t_fine >> 1) - 64000;
+	var2 = ((((var1 >> 2) * (var1 >> 2)) >> 11) * calib->par_p6) >> 2;
+	var2 = var2 + (var1 * calib->par_p5 << 1);
+	var2 = (var2 >> 2) + (calib->par_p4 << 16);
+	var1 = (((((var1 >> 2) * (var1 >> 2)) >> 13) *
+			(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 + (calib->par_p7 << 7)) >> 4;
+
+	return press_comp;
+}
+
+/*
+ * 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)
+{
+	struct bme680_calib *calib = &data->bme680;
+	s32 var1, var2, var3, var4, var5, var6, temp_scaled, calc_hum;
+
+	temp_scaled = (data->t_fine * 5 + 128) >> 8;
+	var1 = (adc_humid - ((s32) ((s32) calib->par_h1 * 16))) -
+		(((temp_scaled * (s32) calib->par_h3) / 100) >> 1);
+	var2 = ((s32) 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 = 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;
+
+	if (calc_hum > 100000) /* Cap at 100%rH */
+		calc_hum = 100000;
+	else if (calc_hum < 0)
+		calc_hum = 0;
+
+	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 */
+	const u32 lookupTable[16] = {2147483647u, 2147483647u,
+				2147483647u, 2147483647u, 2147483647u,
+				2126008810u, 2147483647u, 2130303777u,
+				2147483647u, 2147483647u, 2143188679u,
+				2136746228u, 2147483647u, 2126008810u,
+				2147483647u, 2147483647u};
+
+	var1 = ((1340 + (5 * (s64) calib->range_sw_err)) *
+			((s64) lookupTable[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 = (heatr_res_x100 + 50) / 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;
+}
+
+static int bme680_set_mode(struct bme680_data *data, bool mode)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+
+	if (mode) {
+		ret = regmap_write_bits(data->regmap, BME680_REG_CTRL_MEAS,
+					BME680_MODE_MASK, BME680_MODE_FORCED);
+		if (ret < 0)
+			dev_err(dev, "failed to set forced mode\n");
+
+	} else {
+		ret = regmap_write_bits(data->regmap, BME680_REG_CTRL_MEAS,
+					BME680_MODE_MASK, BME680_MODE_SLEEP);
+		if (ret < 0)
+			dev_err(dev, "failed to set sleep mode\n");
+
+	}
+
+	return ret;
+}
+
+static int bme680_chip_config(struct bme680_data *data)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+	u8 osrs = FIELD_PREP(BME680_OSRS_HUMIDITY_MASK,
+			     data->oversampling_humid + 1);
+	/*
+	 * 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, data->oversampling_temp + 1) |
+	       FIELD_PREP(BME680_OSRS_PRESS_MASK, data->oversampling_press + 1);
+
+	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;
+}
+
+static int bme680_gas_config(struct bme680_data *data)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+	u8 heatr_res, heatr_dur;
+
+	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, "failted to write gas_wait_0 register\n");
+		return ret;
+	}
+
+	/* Selecting the runGas and NB conversion settings for the sensor */
+	ret = regmap_update_bits(data->regmap, BME680_REG_CTRL_GAS_1,
+				 BME680_RUN_GAS_MASK | BME680_NB_CONV_MASK,
+				 BME680_RUN_GAS_EN_BIT | BME680_NB_CONV_0_VAL);
+	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, int *val)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+	__be32 tmp = 0;
+	s32 adc_temp;
+	s16 comp_temp;
+
+	/* set forced mode to trigger measurement */
+	ret = bme680_set_mode(data, true);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_bulk_read(data->regmap, BME680_REG_TEMP_MSB,
+			       (u8 *) &tmp, 3);
+	if (ret < 0) {
+		dev_err(dev, "failed to read temperature\n");
+		return ret;
+	}
+
+	adc_temp = be32_to_cpu(tmp) >> 12;
+	if (adc_temp == BME680_MEAS_SKIPPED) {
+		/* reading was skipped */
+		dev_err(dev, "reading temperature skipped\n");
+		return -EINVAL;
+	}
+	comp_temp = bme680_compensate_temp(data, adc_temp);
+	/*
+	 * val might be NULL if we're called by the read_press/read_humid
+	 * routine which is callled to get t_fine value used in
+	 * compensate_press/compensate_humid to get compensated
+	 * pressure/humidity readings.
+	 */
+	if (val) {
+		*val = comp_temp * 10; /* Centidegrees to millidegrees */
+		return IIO_VAL_INT;
+	}
+
+	return ret;
+}
+
+static int bme680_read_press(struct bme680_data *data,
+			     int *val, int *val2)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+	__be32 tmp = 0;
+	s32 adc_press;
+
+	/* Read and compensate temperature to get a reading of t_fine */
+	ret = bme680_read_temp(data, NULL);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_bulk_read(data->regmap, BME680_REG_PRESS_MSB,
+			       (u8 *) &tmp, 3);
+	if (ret < 0) {
+		dev_err(dev, "failed to read pressure\n");
+		return ret;
+	}
+
+	adc_press = be32_to_cpu(tmp) >> 12;
+	if (adc_press == BME680_MEAS_SKIPPED) {
+		/* reading was skipped */
+		dev_err(dev, "reading pressure skipped\n");
+		return -EINVAL;
+	}
+
+	*val = bme680_compensate_press(data, adc_press);
+	*val2 = 100;
+	return IIO_VAL_FRACTIONAL;
+}
+
+static int bme680_read_humid(struct bme680_data *data,
+			     int *val, int *val2)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+	__be16 tmp = 0;
+	s32 adc_humidity;
+	u32 comp_humidity;
+
+	/* Read and compensate temperature to get a reading of t_fine */
+	ret = bme680_read_temp(data, NULL);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_bulk_read(data->regmap, BM6880_REG_HUMIDITY_MSB,
+			       (u8 *) &tmp, 2);
+	if (ret < 0) {
+		dev_err(dev, "failed to read humidity\n");
+		return ret;
+	}
+
+	adc_humidity = be16_to_cpu(tmp);
+	if (adc_humidity == BME680_MEAS_SKIPPED) {
+		/* reading was skipped */
+		dev_err(dev, "reading humidity skipped\n");
+		return -EINVAL;
+	}
+	comp_humidity = bme680_compensate_humid(data, adc_humidity);
+
+	*val = comp_humidity;
+	*val2 = 1000;
+	return IIO_VAL_FRACTIONAL;
+}
+
+static int bme680_read_gas(struct bme680_data *data,
+			   int *val)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+	__be16 tmp = 0;
+	unsigned int check;
+	u16 adc_gas_res;
+	u8 gas_range;
+
+	/* Set heater settings */
+	ret = bme680_gas_config(data);
+	if (ret < 0) {
+		dev_err(dev, "failed to set gas config\n");
+		return ret;
+	}
+
+	/* set forced mode to trigger measurement */
+	ret = bme680_set_mode(data, true);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_read(data->regmap, BME680_REG_MEAS_STAT_0, &check);
+	if (check & BME680_GAS_MEAS_BIT) {
+		dev_err(dev, "gas measurement incomplete\n");
+		return -EBUSY;
+	}
+
+	ret = regmap_read(data->regmap, BME680_REG_GAS_R_LSB, &check);
+	if (ret < 0) {
+		dev_err(dev, "failed to read gas_r_lsb register\n");
+		return ret;
+	}
+
+	/*
+	 * occurs if either the gas heating duration was insuffient
+	 * to reach the target heater temperature or the target
+	 * heater temperature was too high for the heater sink to
+	 * reach.
+	 */
+	if ((check & BME680_GAS_STAB_BIT) == 0) {
+		dev_err(dev, "heater failed to reach the target temperature\n");
+		return -EINVAL;
+	}
+
+	ret = regmap_bulk_read(data->regmap, BME680_REG_GAS_MSB,
+			       (u8 *) &tmp, 2);
+	if (ret < 0) {
+		dev_err(dev, "failed to read gas resistance\n");
+		return ret;
+	}
+
+	gas_range = check & BME680_GAS_RANGE_MASK;
+	adc_gas_res = be16_to_cpu(tmp) >> BME680_ADC_GAS_RES_SHIFT;
+
+	*val = bme680_compensate_gas(data, adc_gas_res, gas_range);
+	return IIO_VAL_INT;
+}
+
+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);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_PROCESSED:
+		switch (chan->type) {
+		case IIO_TEMP:
+			return bme680_read_temp(data, val);
+		case IIO_PRESSURE:
+			return bme680_read_press(data, val, val2);
+		case IIO_HUMIDITYRELATIVE:
+			return bme680_read_humid(data, val, val2);
+		case IIO_RESISTANCE:
+			return bme680_read_gas(data, val);
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		switch (chan->type) {
+		case IIO_TEMP:
+			*val = 1 << data->oversampling_temp;
+			return IIO_VAL_INT;
+		case IIO_PRESSURE:
+			*val = 1 << data->oversampling_press;
+			return IIO_VAL_INT;
+		case IIO_HUMIDITYRELATIVE:
+			*val = 1 << data->oversampling_humid;
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+}
+
+static int bme680_write_oversampling_ratio_temp(struct bme680_data *data,
+						int val)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(bme680_oversampling_avail); i++) {
+		if (bme680_oversampling_avail[i] == val) {
+			data->oversampling_temp = ilog2(val);
+
+			return bme680_chip_config(data);
+		}
+	}
+
+	return -EINVAL;
+}
+
+static int bme680_write_oversampling_ratio_press(struct bme680_data *data,
+						 int val)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(bme680_oversampling_avail); i++) {
+		if (bme680_oversampling_avail[i] == val) {
+			data->oversampling_press = ilog2(val);
+
+			return bme680_chip_config(data);
+		}
+	}
+
+	return -EINVAL;
+}
+
+static int bme680_write_oversampling_ratio_humid(struct bme680_data *data,
+						 int val)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(bme680_oversampling_avail); i++) {
+		if (bme680_oversampling_avail[i] == val) {
+			data->oversampling_humid = ilog2(val);
+
+			return bme680_chip_config(data);
+		}
+	}
+
+	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);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		switch (chan->type) {
+		case IIO_TEMP:
+			return bme680_write_oversampling_ratio_temp(data, val);
+		case IIO_PRESSURE:
+			return bme680_write_oversampling_ratio_press(data, val);
+		case IIO_HUMIDITYRELATIVE:
+			return bme680_write_oversampling_ratio_humid(data, val);
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+}
+
+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 char *bme680_match_acpi_device(struct device *dev)
+{
+	const struct acpi_device_id *id;
+
+	id = acpi_match_device(dev->driver->acpi_match_table, dev);
+	if (!id)
+		return NULL;
+
+	return dev_name(dev);
+}
+
+int bme680_core_probe(struct device *dev, struct regmap *regmap,
+		      const char *name)
+{
+	struct iio_dev *indio_dev;
+	struct bme680_data *data;
+	unsigned int val;
+	int ret;
+
+	ret = regmap_write(regmap, BME680_REG_SOFT_RESET,
+			   BME680_CMD_SOFTRESET);
+	if (ret < 0) {
+		dev_err(dev, "Failed to reset chip\n");
+		return ret;
+	}
+
+	ret = regmap_read(regmap, BME680_REG_CHIP_ID, &val);
+	if (ret < 0) {
+		dev_err(dev, "Error reading chip ID\n");
+		return ret;
+	}
+
+	if (val != BME680_CHIP_ID_VAL) {
+		dev_err(dev, "Wrong chip ID, got %x expected %x\n",
+				val, BME680_CHIP_ID_VAL);
+		return -ENODEV;
+	}
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	if (!name && ACPI_HANDLE(dev))
+		name = bme680_match_acpi_device(dev);
+
+	data = iio_priv(indio_dev);
+	dev_set_drvdata(dev, indio_dev);
+	data->regmap = regmap;
+	indio_dev->dev.parent = dev;
+	indio_dev->name = name;
+	indio_dev->channels = bme680_channels;
+	indio_dev->num_channels = ARRAY_SIZE(bme680_channels);
+	indio_dev->info = &bme680_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	/* default values for the sensor */
+	data->oversampling_humid = ilog2(2); /* 2X oversampling rate */
+	data->oversampling_press = ilog2(4); /* 4X oversampling rate */
+	data->oversampling_temp = ilog2(8);  /* 8X oversampling rate */
+	data->heater_temp = 320; /* degree Celsius */
+	data->heater_dur = 150;  /* milliseconds */
+
+	ret = bme680_chip_config(data);
+	if (ret < 0) {
+		dev_err(dev, "failed to set chip_config data\n");
+		return ret;
+	}
+
+	ret = bme680_gas_config(data);
+	if (ret < 0) {
+		dev_err(dev, "failed to set gas config data\n");
+		return ret;
+	}
+
+	ret = bme680_read_calib(data, &data->bme680);
+	if (ret < 0) {
+		dev_err(dev,
+			"failed to read calibration coefficients at probe\n");
+		return ret;
+	}
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+EXPORT_SYMBOL_GPL(bme680_core_probe);
+
+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..cfc4449ed
--- /dev/null
+++ b/drivers/iio/chemical/bme680_i2c.c
@@ -0,0 +1,64 @@
+// 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/acpi.h>
+#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)
+{
+	struct regmap *regmap;
+	const char *name = NULL;
+
+	regmap = devm_regmap_init_i2c(client, &bme680_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&client->dev, "Failed to register i2c regmap %d\n",
+				(int)PTR_ERR(regmap));
+		return PTR_ERR(regmap);
+	}
+
+	if (id)
+		name = id->name;
+
+	return bme680_core_probe(&client->dev, regmap, name);
+}
+
+static const struct i2c_device_id bme680_i2c_id[] = {
+	{"bme680", 0},
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, bme680_i2c_id);
+
+static const struct acpi_device_id bme680_acpi_match[] = {
+	{"BME0680", 0},
+	{},
+};
+MODULE_DEVICE_TABLE(acpi, bme680_acpi_match);
+
+static struct i2c_driver bme680_i2c_driver = {
+	.driver = {
+		.name			= "bme680_i2c",
+		.acpi_match_table       = ACPI_PTR(bme680_acpi_match),
+	},
+	.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");
diff --git a/drivers/iio/chemical/bme680_spi.c b/drivers/iio/chemical/bme680_spi.c
new file mode 100644
index 000000000..881778e55
--- /dev/null
+++ b/drivers/iio/chemical/bme680_spi.c
@@ -0,0 +1,166 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * BME680 - SPI Driver
+ *
+ * Copyright (C) 2018 Himanshu Jha <himanshujha199640@gmail.com>
+ */
+#include <linux/acpi.h>
+#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 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;
+	int ret;
+
+	spi->bits_per_word = 8;
+	ret = spi_setup(spi);
+	if (ret < 0) {
+		dev_err(&spi->dev, "spi_setup failed!\n");
+		return ret;
+	}
+
+	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)) {
+		dev_err(&spi->dev, "Failed to register spi regmap %d\n",
+				(int)PTR_ERR(regmap));
+		return PTR_ERR(regmap);
+	}
+
+	return bme680_core_probe(&spi->dev, regmap, id->name);
+}
+
+static const struct spi_device_id bme680_spi_id[] = {
+	{"bme680", 0},
+	{},
+};
+MODULE_DEVICE_TABLE(spi, bme680_spi_id);
+
+static const struct acpi_device_id bme680_acpi_match[] = {
+	{"BME0680", 0},
+	{},
+};
+MODULE_DEVICE_TABLE(acpi, bme680_acpi_match);
+
+static struct spi_driver bme680_spi_driver = {
+	.driver = {
+		.name			= "bme680_spi",
+		.acpi_match_table	= ACPI_PTR(bme680_acpi_match),
+	},
+	.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");
diff --git a/drivers/iio/chemical/ccs811.c b/drivers/iio/chemical/ccs811.c
new file mode 100644
index 000000000..46d5d48b5
--- /dev/null
+++ b/drivers/iio/chemical/ccs811.c
@@ -0,0 +1,489 @@
+/*
+ * 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
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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/delay.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
+
+/* 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;
+	bool drdy_trig_on;
+	/* Ensures correct alignment of timestamp if present */
+	struct {
+		s16 channels[2];
+		s64 ts __aligned(8);
+	} 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 int ccs811_get_measurement(struct ccs811_data *data)
+{
+	int ret, tries = 11;
+
+	/* 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;
+
+	return i2c_smbus_read_i2c_block_data(data->client,
+					    CCS811_ALG_RESULT_DATA, 8,
+					    (char *)&data->buffer);
+}
+
+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:
+		ret = iio_device_claim_direct_mode(indio_dev);
+		if (ret)
+			return ret;
+		mutex_lock(&data->lock);
+		ret = ccs811_get_measurement(data);
+		if (ret < 0) {
+			mutex_unlock(&data->lock);
+			iio_device_release_direct_mode(indio_dev);
+			return ret;
+		}
+
+		switch (chan->type) {
+		case IIO_VOLTAGE:
+			*val = be16_to_cpu(data->buffer.raw_data) &
+					   CCS811_VOLTAGE_MASK;
+			ret = IIO_VAL_INT;
+			break;
+		case IIO_CURRENT:
+			*val = be16_to_cpu(data->buffer.raw_data) >> 10;
+			ret = IIO_VAL_INT;
+			break;
+		case IIO_CONCENTRATION:
+			switch (chan->channel2) {
+			case IIO_MOD_CO2:
+				*val = be16_to_cpu(data->buffer.co2);
+				ret =  IIO_VAL_INT;
+				break;
+			case IIO_MOD_VOC:
+				*val = be16_to_cpu(data->buffer.voc);
+				ret = IIO_VAL_INT;
+				break;
+			default:
+				ret = -EINVAL;
+			}
+			break;
+		default:
+			ret = -EINVAL;
+		}
+		mutex_unlock(&data->lock);
+		iio_device_release_direct_mode(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_timestamp(indio_dev, &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_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	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;
+
+	/* Check hardware id (should be 0x81 for this family of devices) */
+	ret = i2c_smbus_read_byte_data(client, CCS811_HW_ID);
+	if (ret < 0)
+		return ret;
+
+	if (ret != CCS811_HW_ID_VALUE) {
+		dev_err(&client->dev, "hardware id doesn't match CCS81x\n");
+		return -ENODEV;
+	}
+
+	ret = i2c_smbus_read_byte_data(client, CCS811_HW_VERSION);
+	if (ret < 0)
+		return ret;
+
+	if ((ret & CCS811_HW_VERSION_MASK) != CCS811_HW_VERSION_VALUE) {
+		dev_err(&client->dev, "no CCS811 sensor\n");
+		return -ENODEV;
+	}
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	ret = ccs811_setup(client);
+	if (ret < 0)
+		return ret;
+
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;
+
+	mutex_init(&data->lock);
+
+	indio_dev->dev.parent = &client->dev;
+	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) {
+			dev_err(&client->dev, "irq request error %d\n", -ret);
+			goto err_poweroff;
+		}
+
+		data->drdy_trig = devm_iio_trigger_alloc(&client->dev,
+							 "%s-dev%d",
+							 indio_dev->name,
+							 indio_dev->id);
+		if (!data->drdy_trig) {
+			ret = -ENOMEM;
+			goto err_poweroff;
+		}
+
+		data->drdy_trig->dev.parent = &client->dev;
+		data->drdy_trig->ops = &ccs811_trigger_ops;
+		iio_trigger_set_drvdata(data->drdy_trig, indio_dev);
+		indio_dev->trig = data->drdy_trig;
+		iio_trigger_get(indio_dev->trig);
+		ret = iio_trigger_register(data->drdy_trig);
+		if (ret)
+			goto err_poweroff;
+	}
+
+	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 int ccs811_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct ccs811_data *data = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	iio_triggered_buffer_cleanup(indio_dev);
+	if (data->drdy_trig)
+		iio_trigger_unregister(data->drdy_trig);
+
+	return i2c_smbus_write_byte_data(client, CCS811_MEAS_MODE,
+					 CCS811_MODE_IDLE);
+}
+
+static const struct i2c_device_id ccs811_id[] = {
+	{"ccs811", 0},
+	{	}
+};
+MODULE_DEVICE_TABLE(i2c, ccs811_id);
+
+static struct i2c_driver ccs811_driver = {
+	.driver = {
+		.name = "ccs811",
+	},
+	.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/vz89x.c b/drivers/iio/chemical/vz89x.c
new file mode 100644
index 000000000..415b39339
--- /dev/null
+++ b/drivers/iio/chemical/vz89x.c
@@ -0,0 +1,415 @@
+// 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/of.h>
+#include <linux/of_device.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 = (u8 *) &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 = (void *) VZ89X },
+	{ .compatible = "sgx,vz89te", .data = (void *) VZ89TE },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, vz89x_dt_ids);
+
+static int vz89x_probe(struct i2c_client *client,
+		       const struct i2c_device_id *id)
+{
+	struct iio_dev *indio_dev;
+	struct vz89x_data *data;
+	const struct of_device_id *of_id;
+	int chip_id;
+
+	indio_dev = devm_iio_device_alloc(&client->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;
+
+	of_id = of_match_device(vz89x_dt_ids, &client->dev);
+	if (!of_id)
+		chip_id = id->driver_data;
+	else
+		chip_id = (unsigned long)of_id->data;
+
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;
+	data->chip = &vz89x_chips[chip_id];
+	data->last_update = jiffies - HZ;
+	mutex_init(&data->lock);
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->info = &vz89x_info;
+	indio_dev->name = dev_name(&client->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(&client->dev, indio_dev);
+}
+
+static const struct i2c_device_id vz89x_id[] = {
+	{ "vz89x", VZ89X },
+	{ "vz89te", VZ89TE },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, vz89x_id);
+
+static struct i2c_driver vz89x_driver = {
+	.driver = {
+		.name	= "vz89x",
+		.of_match_table = of_match_ptr(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");