blob: f4db44d0d95a8c0b065bf99dccae34b63c70a6af (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
|
<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>If an error is returned, then the original frequency will
be restored.</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>__u32</entry>
<entry><structfield>type</structfield></entry>
<entry>The tuner type. This is the same value as in the
&v4l2-tuner; <structfield>type</structfield> field. See <xref
linkend="v4l2-tuner-type" /></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.
The &v4l2-tuner; <structfield>capability</structfield> field will tell you what the
hardware supports.
</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>ENODATA</errorcode></term>
<listitem>
<para>The hardware seek found no channels.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><errorcode>EBUSY</errorcode></term>
<listitem>
<para>Another hardware seek is already in progress.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
</refentry>
|
