[PATCHv2 3/9] DocBook: document tuner RF gain control

Antti Palosaari
2015-07-16T07:05:31Z

Add brief description for tuner RF gain control.

Cc: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Antti Palosaari <crope@iki.fi>
---
Documentation/DocBook/media/v4l/compat.xml | 4 ++++
Documentation/DocBook/media/v4l/controls.xml | 14 ++++++++++++++
Documentation/DocBook/media/v4l/v4l2.xml | 1 +
3 files changed, 19 insertions(+)

diff --git a/Documentation/DocBook/media/v4l/compat.xml b/Documentation/DocBook/media/v4l/compat.xml
index f56faf5..eb091c7 100644
--- a/Documentation/DocBook/media/v4l/compat.xml
+++ b/Documentation/DocBook/media/v4l/compat.xml
@@ -2600,6 +2600,10 @@ and &v4l2-mbus-framefmt;.
<constant>V4L2_TUNER_ADC</constant> is deprecated now.


+
+ Added <constant>V4L2_CID_RF_TUNER_RF_GAIN</constant>
+RF Tuner control.
+



diff --git a/Documentation/DocBook/media/v4l/controls.xml b/Documentation/DocBook/media/v4l/controls.xml
index 6e1667b..7cae933 100644
--- a/Documentation/DocBook/media/v4l/controls.xml
+++ b/Documentation/DocBook/media/v4l/controls.xml
@@ -5418,6 +5418,18 @@ set. Unit is in Hz. The range and step are driver-specific.</entry>
<entry spanname="descr">Enables/disables IF automatic gain control (AGC)</entry>
</row>
<row>
+ <entry spanname="id"><constant>V4L2_CID_RF_TUNER_RF_GAIN</constant>&nbsp;</entry>
+ <entry>integer</entry>
+ </row>
+ <row>
+ <entry spanname="descr">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.</entry>
+ </row>
+ <row>
<entry spanname="id"><constant>V4L2_CID_RF_TUNER_LNA_GAIN</constant>&nbsp;</entry>
<entry>integer</entry>
</row>
@@ -5425,6 +5437,8 @@ set. Unit is in Hz. The range and step are driver-specific.</entry>
<entry spanname="descr">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 <constant>V4L2_CID_RF_TUNER_LNA_GAIN_AUTO</constant> is not set.
+See <constant>V4L2_CID_RF_TUNER_RF_GAIN</constant> to understand how RF gain
+and LNA gain differs from the each others.
The range and step are driver-specific.</entry>
</row>
<row>
diff --git a/Documentation/DocBook/media/v4l/v4l2.xml b/Documentation/DocBook/media/v4l/v4l2.xml
index c9eedc1..ab9fca4 100644
--- a/Documentation/DocBook/media/v4l/v4l2.xml
+++ b/Documentation/DocBook/media/v4l/v4l2.xml
@@ -156,6 +156,7 @@ applications. -->
<date>2015-05-26</date>
<authorinitials>ap</authorinitials>
<revremark>Renamed V4L2_TUNER_ADC to V4L2_TUNER_SDR.
+Added V4L2_CID_RF_TUNER_RF_GAIN control.