[PATCH] iio: Add ABI documentation for proximity

[Jonathan Cameron <jic23@kernel.org>]

From: Peter Meerwald <pmeerw@pmeerw.net>

has been in use for a long time, but never documented
proximity is unit-less, except otherwise stated, see e.g.
the as3935 driver where it is meter

Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
---
 Documentation/ABI/testing/sysfs-bus-iio | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index a9757dc..738b56f 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -895,6 +895,19 @@ Description:
 		on-chip EEPROM. After power-up or chip reset the device will
 		automatically load the saved configuration.
 
+What:		/sys/.../iio:deviceX/in_proximity_raw
+What:		/sys/.../iio:deviceX/in_proximity_input
+What:		/sys/.../iio:deviceX/in_proximityY_raw
+KernelVersion:	3.4
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Proximity measurement indicating that some
+		object is near the sensor, usually be observing
+		reflectivity of infrared or ultrasound emitted.
+		Often these sensors are unit less and as such conversion
+		to SI units is not possible.  Where it is, the units should
+		be meters.
+
 What:		/sys/.../iio:deviceX/in_illuminanceY_input
 What:		/sys/.../iio:deviceX/in_illuminanceY_raw
 What:		/sys/.../iio:deviceX/in_illuminanceY_mean_raw
-- 
1.9.2