diff --git a/Documentation/DocBook/media/v4l/compat.xml b/Documentation/DocBook/media/v4l/compat.xml
index 08f4efcab4e91756ce6b0fc3c3b1ee6774e22eb4..6c4e95146d160b4a3db5f570750ded0c39e0c5fc 100644
--- a/Documentation/DocBook/media/v4l/compat.xml
+++ b/Documentation/DocBook/media/v4l/compat.xml
@@ -2600,6 +2600,10 @@ and &v4l2-mbus-framefmt;.
V4L2_TUNER_ADC is deprecated now.
+
+ Added V4L2_CID_RF_TUNER_RF_GAIN
+RF Tuner control.
+
diff --git a/Documentation/DocBook/media/v4l/controls.xml b/Documentation/DocBook/media/v4l/controls.xml
index 33aece5418800c51e0b6756e2fc02dc4e222e253..f13a429093f174c406b293a5ca21e8e4d1526e47 100644
--- a/Documentation/DocBook/media/v4l/controls.xml
+++ b/Documentation/DocBook/media/v4l/controls.xml
@@ -5417,6 +5417,18 @@ set. Unit is in Hz. The range and step are driver-specific.
Enables/disables IF automatic gain control (AGC)
+
+ V4L2_CID_RF_TUNER_RF_GAIN
+ integer
+
+
+ The RF amplifier is the very first
+amplifier on the receiver signal path, just right after the antenna input.
+The difference between the LNA gain and the RF gain in this document is that
+the LNA gain is integrated in the tuner chip while the RF gain is a separate
+chip. There may be both RF and LNA gain controls in the same device.
+The range and step are driver-specific.
+
V4L2_CID_RF_TUNER_LNA_GAIN
integer
@@ -5425,6 +5437,8 @@ set. Unit is in Hz. The range and step are driver-specific.
LNA (low noise amplifier) gain is first
gain stage on the RF tuner signal path. It is located very close to tuner
antenna input. Used when V4L2_CID_RF_TUNER_LNA_GAIN_AUTO is not set.
+See V4L2_CID_RF_TUNER_RF_GAIN to understand how RF gain
+and LNA gain differs from the each others.
The range and step are driver-specific.
diff --git a/Documentation/DocBook/media/v4l/v4l2.xml b/Documentation/DocBook/media/v4l/v4l2.xml
index 01a24df92e1db10523faf17ac330b2afbe119fce..9cc4117644fc8ba54ac4cec515dcd51e8ae4e1de 100644
--- a/Documentation/DocBook/media/v4l/v4l2.xml
+++ b/Documentation/DocBook/media/v4l/v4l2.xml
@@ -156,6 +156,7 @@ applications. -->
2015-05-26
ap
Renamed V4L2_TUNER_ADC to V4L2_TUNER_SDR.
+Added V4L2_CID_RF_TUNER_RF_GAIN control.