Exponential Moving Average (EMA) is a first-order IIR filter.

This is a common IIR algorithm used in mcp9600 and others.

Signed-off-by: Ben Collins <bcollins@kernel.org>
---
 Documentation/ABI/testing/sysfs-bus-iio | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index df42a4040530ee96096b998bebc8a08b4fb2d78f..4e30f1db0a930f021cf07e5553d35a3feffddcc2 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -2281,6 +2281,8 @@ Description:
 		  when reading sampling and frequency related attributes of
 		  this filter, and return -EINVAL when trying to write these
 		  attributes.
+		* "ema" - Exponential Moving Average (EMA) is a first-order
+		  Infinite Impulse Response (IIR) filter.
 		* "sinc1" - The digital sinc1 filter. Fast 1st
 		  conversion time. Poor noise performance.
 		* "sinc3" - The digital sinc3 filter. Moderate 1st

-- 
2.39.5