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author | Frederic Weisbecker | 2009-10-18 01:09:09 +0200 |
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committer | Frederic Weisbecker | 2009-10-18 01:12:33 +0200 |
commit | 0f8f86c7bdd1c954fbe153af437a0d91a6c5721a (patch) | |
tree | 94a8d419a470a4f9852ca397bb9bbe48db92ff5c /Documentation/DocBook/v4l/vidioc-g-output.xml | |
parent | Merge branch 'linus' into tracing/hw-breakpoints (diff) | |
parent | perf tools: Move dereference after NULL test (diff) | |
download | kernel-qcow2-linux-0f8f86c7bdd1c954fbe153af437a0d91a6c5721a.tar.gz kernel-qcow2-linux-0f8f86c7bdd1c954fbe153af437a0d91a6c5721a.tar.xz kernel-qcow2-linux-0f8f86c7bdd1c954fbe153af437a0d91a6c5721a.zip |
Merge commit 'perf/core' into perf/hw-breakpoint
Conflicts:
kernel/Makefile
kernel/trace/Makefile
kernel/trace/trace.h
samples/Makefile
Merge reason: We need to be uptodate with the perf events development
branch because we plan to rewrite the breakpoints API on top of
perf events.
Diffstat (limited to 'Documentation/DocBook/v4l/vidioc-g-output.xml')
-rw-r--r-- | Documentation/DocBook/v4l/vidioc-g-output.xml | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/Documentation/DocBook/v4l/vidioc-g-output.xml b/Documentation/DocBook/v4l/vidioc-g-output.xml new file mode 100644 index 000000000000..3ea8c0ed812e --- /dev/null +++ b/Documentation/DocBook/v4l/vidioc-g-output.xml @@ -0,0 +1,100 @@ +<refentry id="vidioc-g-output"> + <refmeta> + <refentrytitle>ioctl VIDIOC_G_OUTPUT, VIDIOC_S_OUTPUT</refentrytitle> + &manvol; + </refmeta> + + <refnamediv> + <refname>VIDIOC_G_OUTPUT</refname> + <refname>VIDIOC_S_OUTPUT</refname> + <refpurpose>Query or select the current video output</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcprototype> + <funcdef>int <function>ioctl</function></funcdef> + <paramdef>int <parameter>fd</parameter></paramdef> + <paramdef>int <parameter>request</parameter></paramdef> + <paramdef>int *<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_G_OUTPUT, VIDIOC_S_OUTPUT</para> + </listitem> + </varlistentry> + <varlistentry> + <term><parameter>argp</parameter></term> + <listitem> + <para></para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>Description</title> + + <para>To query the current video output applications call the +<constant>VIDIOC_G_OUTPUT</constant> ioctl with a pointer to an integer +where the driver stores the number of the output, as in the +&v4l2-output; <structfield>index</structfield> field. This ioctl +will fail only when there are no video outputs, returning the +&EINVAL;.</para> + + <para>To select a video output applications store the number of the +desired output in an integer and call the +<constant>VIDIOC_S_OUTPUT</constant> ioctl with a pointer to this integer. +Side effects are possible. For example outputs may support different +video standards, so the driver may implicitly switch the current +standard. It is good practice to select an output before querying or +negotiating any other parameters.</para> + + <para>Information about video outputs is available using the +&VIDIOC-ENUMOUTPUT; ioctl.</para> + </refsect1> + + <refsect1> + &return-value; + + <variablelist> + <varlistentry> + <term><errorcode>EINVAL</errorcode></term> + <listitem> + <para>The number of the video output is out of bounds, or +there are no video outputs at all and this ioctl is not +supported.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><errorcode>EBUSY</errorcode></term> + <listitem> + <para>I/O is in progress, the output cannot be +switched.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> +</refentry> + +<!-- +Local Variables: +mode: sgml +sgml-parent-document: "v4l2.sgml" +indent-tabs-mode: nil +End: +--> |