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-rw-r--r--Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml76
1 files changed, 66 insertions, 10 deletions
diff --git a/Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml b/Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml
index 407dfceb71f..5b379e75219 100644
--- a/Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml
+++ b/Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml
@@ -52,14 +52,32 @@
<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>
+<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">
@@ -87,7 +105,10 @@ field and the &v4l2-tuner; <structfield>index</structfield> field.</entry>
<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>
+ <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>
@@ -96,7 +117,27 @@ field and the &v4l2-tuner; <structfield>index</structfield> field.</entry>
</row>
<row>
<entry>__u32</entry>
- <entry><structfield>reserved</structfield>[7]</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.
+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.
+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>
@@ -113,14 +154,29 @@ field and the &v4l2-tuner; <structfield>index</structfield> field.</entry>
<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>
+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>The ioctl timed-out. Try again.</para>
+ <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>