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Mauro Carvalho Chehab8e080c22009-09-13 22:16:04 -03001<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>,
Matti Aaltoneneb8942e2010-10-18 10:52:37 -030054<structfield>type</structfield>, <structfield>seek_upward</structfield>,
55<structfield>spacing</structfield> and
Mauro Carvalho Chehab8e080c22009-09-13 22:16:04 -030056<structfield>wrap_around</structfield> fields, and zero out the
57<structfield>reserved</structfield> array of a &v4l2-hw-freq-seek; and
58call the <constant>VIDIOC_S_HW_FREQ_SEEK</constant> ioctl with a pointer
59to this structure.</para>
60
61 <para>This ioctl is supported if the <constant>V4L2_CAP_HW_FREQ_SEEK</constant> capability is set.</para>
62
63 <table pgwide="1" frame="none" id="v4l2-hw-freq-seek">
64 <title>struct <structname>v4l2_hw_freq_seek</structname></title>
65 <tgroup cols="3">
66 &cs-str;
67 <tbody valign="top">
68 <row>
69 <entry>__u32</entry>
70 <entry><structfield>tuner</structfield></entry>
71 <entry>The tuner index number. This is the
72same value as in the &v4l2-input; <structfield>tuner</structfield>
73field and the &v4l2-tuner; <structfield>index</structfield> field.</entry>
74 </row>
75 <row>
76 <entry>&v4l2-tuner-type;</entry>
77 <entry><structfield>type</structfield></entry>
78 <entry>The tuner type. This is the same value as in the
79&v4l2-tuner; <structfield>type</structfield> field.</entry>
80 </row>
81 <row>
82 <entry>__u32</entry>
83 <entry><structfield>seek_upward</structfield></entry>
84 <entry>If non-zero, seek upward from the current frequency, else seek downward.</entry>
85 </row>
86 <row>
87 <entry>__u32</entry>
88 <entry><structfield>wrap_around</structfield></entry>
89 <entry>If non-zero, wrap around when at the end of the frequency range, else stop seeking.</entry>
90 </row>
91 <row>
92 <entry>__u32</entry>
Matti Aaltoneneb8942e2010-10-18 10:52:37 -030093 <entry><structfield>spacing</structfield></entry>
94 <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>
95 </row>
96 <row>
97 <entry>__u32</entry>
98 <entry><structfield>reserved</structfield>[7]</entry>
Mauro Carvalho Chehab8e080c22009-09-13 22:16:04 -030099 <entry>Reserved for future extensions. Drivers and
100 applications must set the array to zero.</entry>
101 </row>
102 </tbody>
103 </tgroup>
104 </table>
105 </refsect1>
106
107 <refsect1>
108 &return-value;
109
110 <variablelist>
111 <varlistentry>
112 <term><errorcode>EINVAL</errorcode></term>
113 <listitem>
114 <para>The <structfield>tuner</structfield> index is out of
115bounds or the value in the <structfield>type</structfield> field is
116wrong.</para>
117 </listitem>
118 </varlistentry>
119 <varlistentry>
120 <term><errorcode>EAGAIN</errorcode></term>
121 <listitem>
122 <para>The ioctl timed-out. Try again.</para>
123 </listitem>
124 </varlistentry>
125 </variablelist>
126 </refsect1>
127</refentry>
128
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