diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index 20312a0e8197..08903b940957 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -1460,3 +1460,14 @@ Description:
 		measurements and return the average value as output data. Each
 		value resulted from <type>[_name]_oversampling_ratio measurements
 		is considered as one sample for <type>[_name]_sampling_frequency.
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_concentration_raw
+What:		/sys/bus/iio/devices/iio:deviceX/in_concentrationX_raw
+What:		/sys/bus/iio/devices/iio:deviceX/in_concentration_co2_raw
+What:		/sys/bus/iio/devices/iio:deviceX/in_concentrationX_co2_raw
+What:		/sys/bus/iio/devices/iio:deviceX/in_concentration_voc_raw
+What:		/sys/bus/iio/devices/iio:deviceX/in_concentrationX_voc_raw
+KernelVersion:	4.3
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Raw (unscaled no offset etc.) percentage reading of a substance.
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index bef690ed0480..ee09a945a2c7 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -75,6 +75,7 @@ static const char * const iio_chan_type_name_spec[] = {
 	[IIO_ENERGY] = "energy",
 	[IIO_DISTANCE] = "distance",
 	[IIO_VELOCITY] = "velocity",
+	[IIO_CONCENTRATION] = "concentration",
 };
 
 static const char * const iio_modifier_names[] = {
@@ -111,6 +112,8 @@ static const char * const iio_modifier_names[] = {
 	[IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z] = "sqrt(x^2+y^2+z^2)",
 	[IIO_MOD_I] = "i",
 	[IIO_MOD_Q] = "q",
+	[IIO_MOD_CO2] = "co2",
+	[IIO_MOD_VOC] = "voc",
 };
 
 /* relies on pairs of these shared then separate */
diff --git a/include/uapi/linux/iio/types.h b/include/uapi/linux/iio/types.h
index 2f8b11722204..1e4c4e346ffb 100644
--- a/include/uapi/linux/iio/types.h
+++ b/include/uapi/linux/iio/types.h
@@ -35,6 +35,7 @@ enum iio_chan_type {
 	IIO_ENERGY,
 	IIO_DISTANCE,
 	IIO_VELOCITY,
+	IIO_CONCENTRATION,
 };
 
 enum iio_modifier {
@@ -72,6 +73,8 @@ enum iio_modifier {
 	IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z,
 	IIO_MOD_I,
 	IIO_MOD_Q,
+	IIO_MOD_CO2,
+	IIO_MOD_VOC,
 };
 
 enum iio_event_type {