V4L/DVB (12761): DocBook: add media API specs
The V4L and DVB API's are there for a long time. however, up to now,
no efforts were done to merge them to kernel DocBook.
This patch adds the current versions of the specs as an unique compendium.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/Documentation/DocBook/v4l/func-ioctl.xml b/Documentation/DocBook/v4l/func-ioctl.xml
new file mode 100644
index 0000000..00f9690e
--- /dev/null
+++ b/Documentation/DocBook/v4l/func-ioctl.xml
@@ -0,0 +1,146 @@
+<refentry id="func-ioctl">
+ <refmeta>
+ <refentrytitle>V4L2 ioctl()</refentrytitle>
+ &manvol;
+ </refmeta>
+
+ <refnamediv>
+ <refname>v4l2-ioctl</refname>
+ <refpurpose>Program a V4L2 device</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <funcsynopsis>
+ <funcsynopsisinfo>#include <sys/ioctl.h></funcsynopsisinfo>
+ <funcprototype>
+ <funcdef>int <function>ioctl</function></funcdef>
+ <paramdef>int <parameter>fd</parameter></paramdef>
+ <paramdef>int <parameter>request</parameter></paramdef>
+ <paramdef>void *<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>V4L2 ioctl request code as defined in the <link
+linkend="videodev">videodev.h</link> header file, for example
+VIDIOC_QUERYCAP.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>argp</parameter></term>
+ <listitem>
+ <para>Pointer to a function parameter, usually a structure.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>The <function>ioctl()</function> function is used to program
+V4L2 devices. The argument <parameter>fd</parameter> must be an open
+file descriptor. An ioctl <parameter>request</parameter> has encoded
+in it whether the argument is an input, output or read/write
+parameter, and the size of the argument <parameter>argp</parameter> in
+bytes. Macros and defines specifying V4L2 ioctl requests are located
+in the <link linkend="videodev">videodev.h</link> header file.
+Applications should use their own copy, not include the version in the
+kernel sources on the system they compile on. All V4L2 ioctl requests,
+their respective function and parameters are specified in <xref
+ linkend="user-func" />.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Return Value</title>
+
+ <para>On success the <function>ioctl()</function> function returns
+<returnvalue>0</returnvalue> and does not reset the
+<varname>errno</varname> variable. On failure
+<returnvalue>-1</returnvalue> is returned, when the ioctl takes an
+output or read/write parameter it remains unmodified, and the
+<varname>errno</varname> variable is set appropriately. See below for
+possible error codes. Generic errors like <errorcode>EBADF</errorcode>
+or <errorcode>EFAULT</errorcode> are not listed in the sections
+discussing individual ioctl requests.</para>
+ <para>Note ioctls may return undefined error codes. Since errors
+may have side effects such as a driver reset applications should
+abort on unexpected errors.</para>
+
+ <variablelist>
+ <varlistentry>
+ <term><errorcode>EBADF</errorcode></term>
+ <listitem>
+ <para><parameter>fd</parameter> is not a valid open file
+descriptor.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><errorcode>EBUSY</errorcode></term>
+ <listitem>
+ <para>The property cannot be changed right now. Typically
+this error code is returned when I/O is in progress or the driver
+supports multiple opens and another process locked the property.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><errorcode>EFAULT</errorcode></term>
+ <listitem>
+ <para><parameter>argp</parameter> references an inaccessible
+memory area.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><errorcode>ENOTTY</errorcode></term>
+ <listitem>
+ <para><parameter>fd</parameter> is not associated with a
+character special device.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><errorcode>EINVAL</errorcode></term>
+ <listitem>
+ <para>The <parameter>request</parameter> or the data pointed
+to by <parameter>argp</parameter> is not valid. This is a very common
+error code, see the individual ioctl requests listed in <xref
+ linkend="user-func" /> for actual causes.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><errorcode>ENOMEM</errorcode></term>
+ <listitem>
+ <para>Not enough physical or virtual memory was available to
+complete the request.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><errorcode>ERANGE</errorcode></term>
+ <listitem>
+ <para>The application attempted to set a control with the
+&VIDIOC-S-CTRL; ioctl to a value which is out of bounds.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+</refentry>
+
+<!--
+Local Variables:
+mode: sgml
+sgml-parent-document: "v4l2.sgml"
+indent-tabs-mode: nil
+End:
+-->