[media] v4l: Image source control class

Add image source control class. This control class is intended to contain
low level controls which deal with control of the image capture process ---
the A/D converter in image sensors, for example.

Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

Documentation/DocBook/media/v4l/controls.xml

@@ -3599,4 +3599,90 @@ interface and may change in the future.</para>
       to <xref linkend="itu-t81"/>, <xref linkend="jfif"/>,
       <xref linkend="w3c-jpeg-jfif"/>.</para>
     </section>
+
+    <section id="image-source-controls">
+      <title>Image Source Control Reference</title>
+
+      <note>
+	<title>Experimental</title>
+
+	<para>This is an <link
+	linkend="experimental">experimental</link> interface and may
+	change in the future.</para>
+      </note>
+
+      <para>
+	The Image Source control class is intended for low-level
+	control of image source devices such as image sensors. The
+	devices feature an analogue to digital converter and a bus
+	transmitter to transmit the image data out of the device.
+      </para>
+
+      <table pgwide="1" frame="none" id="image-source-control-id">
+      <title>Image Source Control IDs</title>
+
+      <tgroup cols="4">
+	<colspec colname="c1" colwidth="1*" />
+	<colspec colname="c2" colwidth="6*" />
+	<colspec colname="c3" colwidth="2*" />
+	<colspec colname="c4" colwidth="6*" />
+	<spanspec namest="c1" nameend="c2" spanname="id" />
+	<spanspec namest="c2" nameend="c4" spanname="descr" />
+	<thead>
+	  <row>
+	    <entry spanname="id" align="left">ID</entry>
+	    <entry align="left">Type</entry>
+	  </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
+	  </row>
+	</thead>
+	<tbody valign="top">
+	  <row><entry></entry></row>
+	  <row>
+	    <entry spanname="id"><constant>V4L2_CID_IMAGE_SOURCE_CLASS</constant></entry>
+	    <entry>class</entry>
+	  </row>
+	  <row>
+	    <entry spanname="descr">The IMAGE_SOURCE class descriptor.</entry>
+	  </row>
+	  <row>
+	    <entry spanname="id"><constant>V4L2_CID_VBLANK</constant></entry>
+	    <entry>integer</entry>
+	  </row>
+	  <row>
+	    <entry spanname="descr">Vertical blanking. The idle period
+	    after every frame during which no image data is produced.
+	    The unit of vertical blanking is a line. Every line has
+	    length of the image width plus horizontal blanking at the
+	    pixel rate defined by
+	    <constant>V4L2_CID_PIXEL_RATE</constant> control in the
+	    same sub-device.</entry>
+	  </row>
+	  <row>
+	    <entry spanname="id"><constant>V4L2_CID_HBLANK</constant></entry>
+	    <entry>integer</entry>
+	  </row>
+	  <row>
+	    <entry spanname="descr">Horizontal blanking. The idle
+	    period after every line of image data during which no
+	    image data is produced. The unit of horizontal blanking is
+	    pixels.</entry>
+	  </row>
+	  <row>
+	    <entry spanname="id"><constant>V4L2_CID_ANALOGUE_GAIN</constant></entry>
+	    <entry>integer</entry>
+	  </row>
+	  <row>
+	    <entry spanname="descr">Analogue gain is gain affecting
+	    all colour components in the pixel matrix. The gain
+	    operation is performed in the analogue domain before A/D
+	    conversion.
+	    </entry>
+	  </row>
+	  <row><entry></entry></row>
+	</tbody>
+      </tgroup>
+      </table>
+
+    </section>
+
 </section>

Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml

@@ -272,6 +272,12 @@ These controls are described in <xref
 These controls are described in <xref
 		linkend="jpeg-controls" />.</entry>
 	  </row>
+	  <row>
+	    <entry><constant>V4L2_CTRL_CLASS_IMAGE_SOURCE</constant></entry>
+	    <entry>0x9e0000</entry> <entry>The class containing image
+	    source controls. These controls are described in <xref
+	    linkend="image-source-controls" />.</entry>
+	  </row>
 	</tbody>
       </tgroup>
     </table>