[media] DocBook: document tuner RF gain control

Add brief description for tuner RF gain control.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
This commit is contained in:
Antti Palosaari 2015-10-10 13:50:59 -03:00 committed by Mauro Carvalho Chehab
parent 41018cb84a
commit b2411b93cd
3 changed files with 19 additions and 0 deletions

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@ -2600,6 +2600,10 @@ and &v4l2-mbus-framefmt;.
<constant>V4L2_TUNER_ADC</constant> is deprecated now.
</para>
</listitem>
<listitem>
<para>Added <constant>V4L2_CID_RF_TUNER_RF_GAIN</constant>
RF Tuner control.</para>
</listitem>
</orderedlist>
</section>

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@ -5417,6 +5417,18 @@ set. Unit is in Hz. The range and step are driver-specific.</entry>
<row>
<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>
@ -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>

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@ -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.
</revremark>
</revision>