1 files changed, 36 insertions, 1 deletions

diff --git a/Documentation/DocBook/v4l/common.xml b/Documentation/DocBook/v4l/common.xml
index b1a81d246d58..cea23e1c4fc6 100644
--- a/Documentation/DocBook/v4l/common.xml
+++ b/Documentation/DocBook/v4l/common.xml
@@ -716,6 +716,41 @@ if (-1 == ioctl (fd, &VIDIOC-S-STD;, &std_id)) {
 }
       </programlisting>
     </example>
+  <section id="dv-timings">
+        <title>Digital Video (DV) Timings</title>
+        <para>
+        The video standards discussed so far has been dealing with Analog TV and the
+corresponding video timings. Today there are many more different hardware interfaces
+such as High Definition TV interfaces (HDMI), VGA, DVI connectors etc., that carry
+video signals and there is a need to extend the API to select the video timings
+for these interfaces. Since it is not possible to extend the &v4l2-std-id; due to
+the limited bits available, a new set of IOCTLs is added to set/get video timings at
+the input and output: </para><itemizedlist>
+        <listitem>
+        <para>DV Presets: Digital Video (DV) presets. These are IDs representing a
+video timing at the input/output. Presets are pre-defined timings implemented
+by the hardware according to video standards. A __u32 data type is used to represent
+a preset unlike the bit mask that is used in &v4l2-std-id; allowing future extensions
+to support as many different presets as needed.</para>
+        </listitem>
+        <listitem>
+        <para>Custom DV Timings: This will allow applications to define more detailed
+custom video timings for the interface. This includes parameters such as width, height,
+polarities, frontporch, backporch etc.
+        </para>
+        </listitem>
+        </itemizedlist>
+        <para>To enumerate and query the attributes of DV presets supported by a device,
+applications use the &VIDIOC-ENUM-DV-PRESETS; ioctl. To get the current DV preset,
+applications use the &VIDIOC-G-DV-PRESET; ioctl and to set a preset they use the
+&VIDIOC-S-DV-PRESET; ioctl.</para>
+        <para>To set custom DV timings for the device, applications use the
+&VIDIOC-S-DV-TIMINGS; ioctl and to get current custom DV timings they use the
+&VIDIOC-G-DV-TIMINGS; ioctl.</para>
+        <para>Applications can make use of the <xref linkend="input-capabilities" /> and
+<xref linkend="output-capabilities"/> flags to decide what ioctls are available to set the
+video timings for the device.</para>
+        </section>
   </section>
 
   &sub-controls;
@@ -1135,7 +1170,7 @@ frames per second. If less than this number of frames is to be
 captured or output, applications can request frame skipping or
 duplicating on the driver side. This is especially useful when using
 the &func-read; or &func-write;, which are not augmented by timestamps
-or sequence counters, and to avoid unneccessary data copying.</para>
+or sequence counters, and to avoid unnecessary data copying.</para>
 
     <para>Finally these ioctls can be used to determine the number of
 buffers used internally by a driver in read/write mode. For