[media] V4L: Add camera ISO sensitivity controls

Add ISO sensitivity and ISO auto/manual controls. The sensitivity
values are related to level of amplification of the analog signal
between image sensor and ADC. These controls allow to support sensors
exposing an interface to accept the ISO values directly.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/Documentation/DocBook/media/v4l/controls.xml b/Documentation/DocBook/media/v4l/controls.xml
index 74876b4..8fccfe1 100644
--- a/Documentation/DocBook/media/v4l/controls.xml
+++ b/Documentation/DocBook/media/v4l/controls.xml
@@ -3117,6 +3117,44 @@
 	  </row>
 	  <row><entry></entry></row>
 
+	  <row>
+	    <entry spanname="id"><constant>V4L2_CID_ISO_SENSITIVITY</constant>&nbsp;</entry>
+	    <entry>integer menu</entry>
+	  </row><row><entry spanname="descr">Determines ISO equivalent of an
+image sensor indicating the sensor's sensitivity to light. The numbers are
+expressed in arithmetic scale, as per <xref linkend="iso12232" /> standard,
+where doubling the sensor sensitivity is represented by doubling the numerical
+ISO value. Applications should interpret the values as standard ISO values
+multiplied by 1000, e.g. control value 800 stands for ISO 0.8. Drivers will
+usually support only a subset of standard ISO values. The effect of setting
+this control while the <constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant>
+control is set to a value other than <constant>V4L2_CID_ISO_SENSITIVITY_MANUAL
+</constant> is undefined, drivers should ignore such requests.</entry>
+	  </row>
+	  <row><entry></entry></row>
+
+	  <row id="v4l2-iso-sensitivity-auto-type">
+	    <entry spanname="id"><constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant>&nbsp;</entry>
+	    <entry>enum&nbsp;v4l2_iso_sensitivity_type</entry>
+	  </row><row><entry spanname="descr">Enables or disables automatic ISO
+sensitivity adjustments.</entry>
+	  </row>
+	  <row>
+	    <entrytbl spanname="descr" cols="2">
+	      <tbody valign="top">
+		<row>
+		  <entry><constant>V4L2_CID_ISO_SENSITIVITY_MANUAL</constant>&nbsp;</entry>
+		  <entry>Manual ISO sensitivity.</entry>
+		</row>
+		<row>
+		  <entry><constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant>&nbsp;</entry>
+		  <entry>Automatic ISO sensitivity adjustments.</entry>
+		</row>
+	      </tbody>
+	    </entrytbl>
+	  </row>
+	  <row><entry></entry></row>
+
 	</tbody>
       </tgroup>
     </table>