mirror of https://gitee.com/openkylin/linux.git
128 lines
3.9 KiB
XML
128 lines
3.9 KiB
XML
<refentry id="vidioc-s-hw-freq-seek">
|
|
<refmeta>
|
|
<refentrytitle>ioctl VIDIOC_S_HW_FREQ_SEEK</refentrytitle>
|
|
&manvol;
|
|
</refmeta>
|
|
|
|
<refnamediv>
|
|
<refname>VIDIOC_S_HW_FREQ_SEEK</refname>
|
|
<refpurpose>Perform a hardware frequency seek</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_hw_freq_seek
|
|
*<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_S_HW_FREQ_SEEK</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><parameter>argp</parameter></term>
|
|
<listitem>
|
|
<para></para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Description</title>
|
|
|
|
<para>Start a hardware frequency seek from the current frequency.
|
|
To do this applications initialize the <structfield>tuner</structfield>,
|
|
<structfield>type</structfield>, <structfield>seek_upward</structfield>,
|
|
<structfield>spacing</structfield> and
|
|
<structfield>wrap_around</structfield> fields, and zero out the
|
|
<structfield>reserved</structfield> array of a &v4l2-hw-freq-seek; and
|
|
call the <constant>VIDIOC_S_HW_FREQ_SEEK</constant> ioctl with a pointer
|
|
to this structure.</para>
|
|
|
|
<para>This ioctl is supported if the <constant>V4L2_CAP_HW_FREQ_SEEK</constant> capability is set.</para>
|
|
|
|
<table pgwide="1" frame="none" id="v4l2-hw-freq-seek">
|
|
<title>struct <structname>v4l2_hw_freq_seek</structname></title>
|
|
<tgroup cols="3">
|
|
&cs-str;
|
|
<tbody valign="top">
|
|
<row>
|
|
<entry>__u32</entry>
|
|
<entry><structfield>tuner</structfield></entry>
|
|
<entry>The tuner index number. This is the
|
|
same value as in the &v4l2-input; <structfield>tuner</structfield>
|
|
field and the &v4l2-tuner; <structfield>index</structfield> field.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>&v4l2-tuner-type;</entry>
|
|
<entry><structfield>type</structfield></entry>
|
|
<entry>The tuner type. This is the same value as in the
|
|
&v4l2-tuner; <structfield>type</structfield> field.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>__u32</entry>
|
|
<entry><structfield>seek_upward</structfield></entry>
|
|
<entry>If non-zero, seek upward from the current frequency, else seek downward.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>__u32</entry>
|
|
<entry><structfield>wrap_around</structfield></entry>
|
|
<entry>If non-zero, wrap around when at the end of the frequency range, else stop seeking.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>__u32</entry>
|
|
<entry><structfield>spacing</structfield></entry>
|
|
<entry>If non-zero, defines the hardware seek resolution in Hz. The driver selects the nearest value that is supported by the device. If spacing is zero a reasonable default value is used.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>__u32</entry>
|
|
<entry><structfield>reserved</structfield>[7]</entry>
|
|
<entry>Reserved for future extensions. Applications
|
|
must set the array to zero.</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
&return-value;
|
|
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><errorcode>EINVAL</errorcode></term>
|
|
<listitem>
|
|
<para>The <structfield>tuner</structfield> index is out of
|
|
bounds, the wrap_around value is not supported or the value in the <structfield>type</structfield> field is
|
|
wrong.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><errorcode>EAGAIN</errorcode></term>
|
|
<listitem>
|
|
<para>The ioctl timed-out. Try again.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</refsect1>
|
|
</refentry>
|