• Home
  • History
  • Annotate
  • Line#
  • Navigate
  • Raw
  • Download
  • only in /asuswrt-rt-n18u-9.0.0.4.380.2695/release/src-rt-6.x.4708/linux/linux-2.6/Documentation/DocBook/v4l/
1<refentry id="vidioc-s-hw-freq-seek">
2  <refmeta>
3    <refentrytitle>ioctl VIDIOC_S_HW_FREQ_SEEK</refentrytitle>
4    &manvol;
5  </refmeta>
6
7  <refnamediv>
8    <refname>VIDIOC_S_HW_FREQ_SEEK</refname>
9    <refpurpose>Perform a hardware frequency seek</refpurpose>
10  </refnamediv>
11
12  <refsynopsisdiv>
13    <funcsynopsis>
14      <funcprototype>
15	<funcdef>int <function>ioctl</function></funcdef>
16	<paramdef>int <parameter>fd</parameter></paramdef>
17	<paramdef>int <parameter>request</parameter></paramdef>
18	<paramdef>struct v4l2_hw_freq_seek
19*<parameter>argp</parameter></paramdef>
20      </funcprototype>
21    </funcsynopsis>
22  </refsynopsisdiv>
23
24  <refsect1>
25    <title>Arguments</title>
26
27    <variablelist>
28      <varlistentry>
29	<term><parameter>fd</parameter></term>
30	<listitem>
31	  <para>&fd;</para>
32	</listitem>
33      </varlistentry>
34      <varlistentry>
35	<term><parameter>request</parameter></term>
36	<listitem>
37	  <para>VIDIOC_S_HW_FREQ_SEEK</para>
38	</listitem>
39      </varlistentry>
40      <varlistentry>
41	<term><parameter>argp</parameter></term>
42	<listitem>
43	  <para></para>
44	</listitem>
45      </varlistentry>
46    </variablelist>
47  </refsect1>
48
49  <refsect1>
50    <title>Description</title>
51
52    <para>Start a hardware frequency seek from the current frequency.
53To do this applications initialize the <structfield>tuner</structfield>,
54<structfield>type</structfield>, <structfield>seek_upward</structfield> and
55<structfield>wrap_around</structfield> fields, and zero out the
56<structfield>reserved</structfield> array of a &v4l2-hw-freq-seek; and
57call the <constant>VIDIOC_S_HW_FREQ_SEEK</constant> ioctl with a pointer
58to this structure.</para>
59
60    <para>This ioctl is supported if the <constant>V4L2_CAP_HW_FREQ_SEEK</constant> capability is set.</para>
61
62    <table pgwide="1" frame="none" id="v4l2-hw-freq-seek">
63      <title>struct <structname>v4l2_hw_freq_seek</structname></title>
64      <tgroup cols="3">
65	&cs-str;
66	<tbody valign="top">
67	  <row>
68	    <entry>__u32</entry>
69	    <entry><structfield>tuner</structfield></entry>
70	    <entry>The tuner index number. This is the
71same value as in the &v4l2-input; <structfield>tuner</structfield>
72field and the &v4l2-tuner; <structfield>index</structfield> field.</entry>
73	  </row>
74	  <row>
75	    <entry>&v4l2-tuner-type;</entry>
76	    <entry><structfield>type</structfield></entry>
77	    <entry>The tuner type. This is the same value as in the
78&v4l2-tuner; <structfield>type</structfield> field.</entry>
79	  </row>
80	  <row>
81	    <entry>__u32</entry>
82	    <entry><structfield>seek_upward</structfield></entry>
83	    <entry>If non-zero, seek upward from the current frequency, else seek downward.</entry>
84	  </row>
85	  <row>
86	    <entry>__u32</entry>
87	    <entry><structfield>wrap_around</structfield></entry>
88	    <entry>If non-zero, wrap around when at the end of the frequency range, else stop seeking.</entry>
89	  </row>
90	  <row>
91	    <entry>__u32</entry>
92	    <entry><structfield>reserved</structfield>[8]</entry>
93	    <entry>Reserved for future extensions. Drivers and
94	    applications must set the array to zero.</entry>
95	  </row>
96	</tbody>
97      </tgroup>
98    </table>
99  </refsect1>
100
101  <refsect1>
102    &return-value;
103
104    <variablelist>
105      <varlistentry>
106	<term><errorcode>EINVAL</errorcode></term>
107	<listitem>
108	  <para>The <structfield>tuner</structfield> index is out of
109bounds or the value in the <structfield>type</structfield> field is
110wrong.</para>
111	</listitem>
112      </varlistentry>
113      <varlistentry>
114	<term><errorcode>EAGAIN</errorcode></term>
115	<listitem>
116	  <para>The ioctl timed-out. Try again.</para>
117	</listitem>
118      </varlistentry>
119    </variablelist>
120  </refsect1>
121</refentry>
122
123<!--
124Local Variables:
125mode: sgml
126sgml-parent-document: "v4l2.sgml"
127indent-tabs-mode: nil
128End:
129-->
130