summaryrefslogtreecommitdiffstats
path: root/kernel/Documentation/DocBook/media/v4l/func-ioctl.xml
diff options
context:
space:
mode:
authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/Documentation/DocBook/media/v4l/func-ioctl.xml
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/Documentation/DocBook/media/v4l/func-ioctl.xml')
-rw-r--r--kernel/Documentation/DocBook/media/v4l/func-ioctl.xml71
1 files changed, 71 insertions, 0 deletions
diff --git a/kernel/Documentation/DocBook/media/v4l/func-ioctl.xml b/kernel/Documentation/DocBook/media/v4l/func-ioctl.xml
new file mode 100644
index 000000000..4394184a1
--- /dev/null
+++ b/kernel/Documentation/DocBook/media/v4l/func-ioctl.xml
@@ -0,0 +1,71 @@
+<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 &lt;sys/ioctl.h&gt;</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 <filename>videodev2.h</filename> 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 <filename>videodev2.h</filename> 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>
+ &return-value;
+ <para>When an ioctl that takes an output or read/write parameter fails,
+ the parameter remains unmodified.</para>
+ </refsect1>
+</refentry>