summaryrefslogtreecommitdiffstats
path: root/kernel/Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml')
-rw-r--r--kernel/Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml188
1 files changed, 188 insertions, 0 deletions
diff --git a/kernel/Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml b/kernel/Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml
new file mode 100644
index 000000000..a5fc4c488
--- /dev/null
+++ b/kernel/Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml
@@ -0,0 +1,188 @@
+<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>wrap_around</structfield>, <structfield>spacing</structfield>,
+<structfield>rangelow</structfield> and <structfield>rangehigh</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>The <structfield>rangelow</structfield> and
+<structfield>rangehigh</structfield> fields can be set to a non-zero value to
+tell the driver to search a specific band. If the &v4l2-tuner;
+<structfield>capability</structfield> field has the
+<constant>V4L2_TUNER_CAP_HWSEEK_PROG_LIM</constant> flag set, these values
+must fall within one of the bands returned by &VIDIOC-ENUM-FREQ-BANDS;. If
+the <constant>V4L2_TUNER_CAP_HWSEEK_PROG_LIM</constant> flag is not set,
+then these values must exactly match those of one of the bands returned by
+&VIDIOC-ENUM-FREQ-BANDS;. If the current frequency of the tuner does not fall
+within the selected band it will be clamped to fit in the band before the
+seek is started.</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>
+
+ <para>If this ioctl is called from a non-blocking filehandle, then &EAGAIN; is
+ returned and no seek takes place.</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>rangelow</structfield></entry>
+ <entry>If non-zero, the lowest tunable frequency of the band to
+search in units of 62.5 kHz, or if the &v4l2-tuner;
+<structfield>capability</structfield> field has the
+<constant>V4L2_TUNER_CAP_LOW</constant> flag set, in units of 62.5 Hz or if the &v4l2-tuner;
+<structfield>capability</structfield> field has the
+<constant>V4L2_TUNER_CAP_1HZ</constant> flag set, in units of 1 Hz.
+If <structfield>rangelow</structfield> is zero a reasonable default value
+is used.</entry>
+ </row>
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>rangehigh</structfield></entry>
+ <entry>If non-zero, the highest tunable frequency of the band to
+search in units of 62.5 kHz, or if the &v4l2-tuner;
+<structfield>capability</structfield> field has the
+<constant>V4L2_TUNER_CAP_LOW</constant> flag set, in units of 62.5 Hz or if the &v4l2-tuner;
+<structfield>capability</structfield> field has the
+<constant>V4L2_TUNER_CAP_1HZ</constant> flag set, in units of 1 Hz.
+If <structfield>rangehigh</structfield> is zero a reasonable default value
+is used.</entry>
+ </row>
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>reserved</structfield>[5]</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 <structfield>wrap_around</structfield> value is not supported or
+one of the values in the <structfield>type</structfield>,
+<structfield>rangelow</structfield> or <structfield>rangehigh</structfield>
+fields is wrong.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><errorcode>EAGAIN</errorcode></term>
+ <listitem>
+ <para>Attempted to call <constant>VIDIOC_S_HW_FREQ_SEEK</constant>
+ with the filehandle in non-blocking mode.</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>