Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / Documentation / DocBook / media / v4l / vidioc-querystd.xml
diff --git a/kernel/Documentation/DocBook/media/v4l/vidioc-querystd.xml b/kernel/Documentation/DocBook/media/v4l/vidioc-querystd.xml
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+<refentry id="vidioc-querystd">
+  <refmeta>
+    <refentrytitle>ioctl VIDIOC_QUERYSTD</refentrytitle>
+    &manvol;
+  </refmeta>
+
+  <refnamediv>
+    <refname>VIDIOC_QUERYSTD</refname>
+    <refpurpose>Sense the video standard received by the current
+input</refpurpose>
+  </refnamediv>
+
+  <refsynopsisdiv>
+    <funcsynopsis>
+      <funcprototype>
+       <funcdef>int <function>ioctl</function></funcdef>
+       <paramdef>int <parameter>fd</parameter></paramdef>
+       <paramdef>int <parameter>request</parameter></paramdef>
+       <paramdef>v4l2_std_id *<parameter>argp</parameter></paramdef>
+      </funcprototype>
+    </funcsynopsis>
+  </refsynopsisdiv>
+
+  <refsect1>
+    <title>Arguments</title>
+
+    <variablelist>
+       <varlistentry>
+       <term><parameter>fd</parameter></term>
+       <listitem>
+         <para>&fd;</para>
+       </listitem>
+      </varlistentry>
+      <varlistentry>
+       <term><parameter>request</parameter></term>
+       <listitem>
+         <para>VIDIOC_QUERYSTD</para>
+       </listitem>
+      </varlistentry>
+      <varlistentry>
+       <term><parameter>argp</parameter></term>
+       <listitem>
+         <para></para>
+       </listitem>
+      </varlistentry>
+    </variablelist>
+  </refsect1>
+
+  <refsect1>
+    <title>Description</title>
+
+    <para>The hardware may be able to detect the current video
+standard automatically. To do so, applications call <constant>
+VIDIOC_QUERYSTD</constant> with a pointer to a &v4l2-std-id; type. The
+driver stores here a set of candidates, this can be a single flag or a
+set of supported standards if for example the hardware can only
+distinguish between 50 and 60 Hz systems. If no signal was detected,
+then the driver will return V4L2_STD_UNKNOWN. When detection is not
+possible or fails, the set must contain all standards supported by the
+current video input or output.</para>
+
+  </refsect1>
+
+  <refsect1>
+    &return-value;
+    <variablelist>
+      <varlistentry>
+       <term><errorcode>ENODATA</errorcode></term>
+       <listitem>
+         <para>Standard video timings are not supported for this input or output.</para>
+       </listitem>
+      </varlistentry>
+    </variablelist>
+  </refsect1>
+</refentry>