iio: ph: add IIO_PH channel type

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

3 files changed, 9 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index 8fadd272ad8a..80c6fce9935b 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -1493,3 +1493,10 @@ Description:
                 This ABI is especially applicable for humidity sensors
                 to heatup the device and get rid of any condensation
                 in some humidity environment
+
+What:           /sys/bus/iio/devices/iio:deviceX/in_ph_raw
+KernelVersion:  4.5
+Contact:        linux-iio@vger.kernel.org
+Description:
+                Raw (unscaled no offset etc.) pH reading of a substance as a negative
+                base-10 logarithm of hydrodium ions in a litre of water.
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index fd01f3493fc7..eb01a83a5b7c 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -77,6 +77,7 @@ static const char * const iio_chan_type_name_spec[] = {
         [IIO_VELOCITY] = "velocity",
         [IIO_CONCENTRATION] = "concentration",
         [IIO_RESISTANCE] = "resistance",
+        [IIO_PH] = "ph",
 };
 
 static const char * const iio_modifier_names[] = {
diff --git a/include/uapi/linux/iio/types.h b/include/uapi/linux/iio/types.h
index 7c63bd67c36e..c077617f3304 100644
--- a/include/uapi/linux/iio/types.h
+++ b/include/uapi/linux/iio/types.h
@@ -37,6 +37,7 @@ enum iio_chan_type {
         IIO_VELOCITY,
         IIO_CONCENTRATION,
         IIO_RESISTANCE,
+        IIO_PH,
 };
 
 enum iio_modifier {