iio: Add ABI documentation for illuminance

has been in use for a long time, but never documented;
state that this measurement should be in lux (drivers may feel
different about this)

Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index 9669c1f..a9757dc 100644 (file)
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -895,6 +895,15 @@ Description:
                on-chip EEPROM. After power-up or chip reset the device will
                automatically load the saved configuration.
 
+What:          /sys/.../iio:deviceX/in_illuminanceY_input
+What:          /sys/.../iio:deviceX/in_illuminanceY_raw
+What:          /sys/.../iio:deviceX/in_illuminanceY_mean_raw
+KernelVersion: 3.4
+Contact:       linux-iio@vger.kernel.org
+Description:
+               Illuminance measurement, units after application of scale
+               and offset are lux.
+
 What:          /sys/.../iio:deviceX/in_intensityY_raw
 What:          /sys/.../iio:deviceX/in_intensityY_ir_raw
 What:          /sys/.../iio:deviceX/in_intensityY_both_raw