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author | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
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committer | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
commit | 871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch) | |
tree | 8718f573808810c2a1e8cb8fb6ac469093ca2784 /Documentation/DocBook/media/v4l/vidioc-g-ctrl.xml | |
parent | 9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff) | |
download | FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.gz FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.bz2 FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.zip |
Moved, renamed, and deleted files
The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.
Diffstat (limited to 'Documentation/DocBook/media/v4l/vidioc-g-ctrl.xml')
-rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-g-ctrl.xml | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/Documentation/DocBook/media/v4l/vidioc-g-ctrl.xml b/Documentation/DocBook/media/v4l/vidioc-g-ctrl.xml new file mode 100644 index 00000000..12b1d050 --- /dev/null +++ b/Documentation/DocBook/media/v4l/vidioc-g-ctrl.xml @@ -0,0 +1,129 @@ +<refentry id="vidioc-g-ctrl"> + <refmeta> + <refentrytitle>ioctl VIDIOC_G_CTRL, VIDIOC_S_CTRL</refentrytitle> + &manvol; + </refmeta> + + <refnamediv> + <refname>VIDIOC_G_CTRL</refname> + <refname>VIDIOC_S_CTRL</refname> + <refpurpose>Get or set the value of a control</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcprototype> + <funcdef>int <function>ioctl</function></funcdef> + <paramdef>int <parameter>fd</parameter></paramdef> + <paramdef>int <parameter>request</parameter></paramdef> + <paramdef>struct v4l2_control +*<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_CTRL, VIDIOC_S_CTRL</para> + </listitem> + </varlistentry> + <varlistentry> + <term><parameter>argp</parameter></term> + <listitem> + <para></para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>Description</title> + + <para>To get the current value of a control applications +initialize the <structfield>id</structfield> field of a struct +<structname>v4l2_control</structname> and call the +<constant>VIDIOC_G_CTRL</constant> ioctl with a pointer to this +structure. To change the value of a control applications initialize +the <structfield>id</structfield> and <structfield>value</structfield> +fields of a struct <structname>v4l2_control</structname> and call the +<constant>VIDIOC_S_CTRL</constant> ioctl.</para> + + <para>When the <structfield>id</structfield> is invalid drivers +return an &EINVAL;. When the <structfield>value</structfield> is out +of bounds drivers can choose to take the closest valid value or return +an &ERANGE;, whatever seems more appropriate. However, +<constant>VIDIOC_S_CTRL</constant> is a write-only ioctl, it does not +return the actual new value.</para> + + <para>These ioctls work only with user controls. For other +control classes the &VIDIOC-G-EXT-CTRLS;, &VIDIOC-S-EXT-CTRLS; or +&VIDIOC-TRY-EXT-CTRLS; must be used.</para> + + <table pgwide="1" frame="none" id="v4l2-control"> + <title>struct <structname>v4l2_control</structname></title> + <tgroup cols="3"> + &cs-str; + <tbody valign="top"> + <row> + <entry>__u32</entry> + <entry><structfield>id</structfield></entry> + <entry>Identifies the control, set by the +application.</entry> + </row> + <row> + <entry>__s32</entry> + <entry><structfield>value</structfield></entry> + <entry>New value or current value.</entry> + </row> + </tbody> + </tgroup> + </table> + </refsect1> + + <refsect1> + &return-value; + + <variablelist> + <varlistentry> + <term><errorcode>EINVAL</errorcode></term> + <listitem> + <para>The &v4l2-control; <structfield>id</structfield> is +invalid.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><errorcode>ERANGE</errorcode></term> + <listitem> + <para>The &v4l2-control; <structfield>value</structfield> +is out of bounds.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><errorcode>EBUSY</errorcode></term> + <listitem> + <para>The control is temporarily not changeable, possibly +because another applications took over control of the device function +this control belongs to.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><errorcode>EACCES</errorcode></term> + <listitem> + <para>Attempt to set a read-only control or to get a + write-only control.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> +</refentry> |