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[media] v4l2 spec: add VIDIOC_ENUM_FREQ_BANDS documentation

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Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Hans Verkuil 2012-07-05 06:54:38 -03:00 committed by Mauro Carvalho Chehab
parent 82b655bfc3
commit 50121317c2
5 changed files with 221 additions and 9 deletions
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12
Documentation/DocBook/media/v4l/compat.xml
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@ -2480,6 +2480,15 @@ that used it. It was originally scheduled for removal in 2.6.35.
</orderedlist>
</section>
<section>
<title>V4L2 in Linux 3.6</title>
<orderedlist>
<listitem>
<para>Added support for frequency band enumerations: &VIDIOC-ENUM-FREQ-BANDS;.</para>
</listitem>
</orderedlist>
</section>
<section id="other">
<title>Relation of V4L2 to other Linux multimedia APIs</title>
@ -2609,6 +2618,9 @@ ioctls.</para>
<para><link linkend="v4l2-auto-focus-area"><constant>
V4L2_CID_AUTO_FOCUS_AREA</constant></link> control.</para>
</listitem>
<listitem>
<para>Support for frequency band enumeration: &VIDIOC-ENUM-FREQ-BANDS; ioctl.</para>
</listitem>
</itemizedlist>
</section>

6
Documentation/DocBook/media/v4l/v4l2.xml
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@ -140,6 +140,11 @@ structs, ioctls) must be noted in more detail in the history chapter
applications. -->
<revision>
<revnumber>3.6</revnumber>
<date>2012-07-02</date>
<authorinitials>hv</authorinitials>
<revremark>Added VIDIOC_ENUM_FREQ_BANDS.
</revremark>
<revnumber>3.5</revnumber>
<date>2012-05-07</date>
<authorinitials>sa, sn</authorinitials>
@ -534,6 +539,7 @@ and discussions on the V4L mailing list.</revremark>
&sub-enum-fmt;
&sub-enum-framesizes;
&sub-enum-frameintervals;
&sub-enum-freq-bands;
&sub-enuminput;
&sub-enumoutput;
&sub-enumstd;

179
Documentation/DocBook/media/v4l/vidioc-enum-freq-bands.xml Normal file
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@ -0,0 +1,179 @@
<refentry id="vidioc-enum-freq-bands">
<refmeta>
<refentrytitle>ioctl VIDIOC_ENUM_FREQ_BANDS</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>VIDIOC_ENUM_FREQ_BANDS</refname>
<refpurpose>Enumerate supported frequency bands</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_frequency_band
*<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_ENUM_FREQ_BANDS</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>argp</parameter></term>
<listitem>
<para></para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<note>
<title>Experimental</title>
<para>This is an <link linkend="experimental"> experimental </link>
interface and may change in the future.</para>
</note>
<para>Enumerates the frequency bands that a tuner or modulator supports.
To do this applications initialize the <structfield>tuner</structfield>,
<structfield>type</structfield> and <structfield>index</structfield> fields,
and zero out the <structfield>reserved</structfield> array of a &v4l2-frequency-band; and
call the <constant>VIDIOC_ENUM_FREQ_BANDS</constant> ioctl with a pointer
to this structure.</para>
<para>This ioctl is supported if the <constant>V4L2_TUNER_CAP_FREQ_BANDS</constant> capability
of the corresponding tuner/modulator is set.</para>
<table pgwide="1" frame="none" id="v4l2-frequency-band">
<title>struct <structname>v4l2_frequency_band</structname></title>
<tgroup cols="3">
&cs-str;
<tbody valign="top">
<row>
<entry>__u32</entry>
<entry><structfield>tuner</structfield></entry>
<entry>The tuner or modulator index number. This is the
same value as in the &v4l2-input; <structfield>tuner</structfield>
field and the &v4l2-tuner; <structfield>index</structfield> field, or
the &v4l2-output; <structfield>modulator</structfield> field and the
&v4l2-modulator; <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. The type must be set
to <constant>V4L2_TUNER_RADIO</constant> for <filename>/dev/radioX</filename>
device nodes, and to <constant>V4L2_TUNER_ANALOG_TV</constant>
for all others. Set this field to <constant>V4L2_TUNER_RADIO</constant> for
modulators (currently only radio modulators are supported).
See <xref linkend="v4l2-tuner-type" /></entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>index</structfield></entry>
<entry>Identifies the frequency band, set by the application.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>capability</structfield></entry>
<entry spanname="hspan">The tuner/modulator capability flags for
this frequency band, see <xref linkend="tuner-capability" />. The <constant>V4L2_TUNER_CAP_LOW</constant>
capability must be the same for all frequency bands of the selected tuner/modulator.
So either all bands have that capability set, or none of them have that capability.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>rangelow</structfield></entry>
<entry spanname="hspan">The lowest tunable frequency in
units of 62.5 kHz, or if the <structfield>capability</structfield>
flag <constant>V4L2_TUNER_CAP_LOW</constant> is set, in units of 62.5
Hz, for this frequency band.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>rangehigh</structfield></entry>
<entry spanname="hspan">The highest tunable frequency in
units of 62.5 kHz, or if the <structfield>capability</structfield>
flag <constant>V4L2_TUNER_CAP_LOW</constant> is set, in units of 62.5
Hz, for this frequency band.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>modulation</structfield></entry>
<entry spanname="hspan">The supported modulation systems of this frequency band.
See <xref linkend="band-modulation" />. Note that currently only one
modulation system per frequency band is supported. More work will need to
be done if multiple modulation systems are possible. Contact the
linux-media mailing list (&v4l-ml;) if you need that functionality.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>reserved</structfield>[9]</entry>
<entry>Reserved for future extensions. Applications and drivers
must set the array to zero.</entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="band-modulation">
<title>Band Modulation Systems</title>
<tgroup cols="3">
&cs-def;
<tbody valign="top">
<row>
<entry><constant>V4L2_BAND_MODULATION_VSB</constant></entry>
<entry>0x02</entry>
<entry>Vestigial Sideband modulation, used for analog TV.</entry>
</row>
<row>
<entry><constant>V4L2_BAND_MODULATION_FM</constant></entry>
<entry>0x04</entry>
<entry>Frequency Modulation, commonly used for analog radio.</entry>
</row>
<row>
<entry><constant>V4L2_BAND_MODULATION_AM</constant></entry>
<entry>0x08</entry>
<entry>Amplitude Modulation, commonly used for analog radio.</entry>
</row>
</tbody>
</tgroup>
</table>
</refsect1>
<refsect1>
&return-value;
<variablelist>
<varlistentry>
<term><errorcode>EINVAL</errorcode></term>
<listitem>
<para>The <structfield>tuner</structfield> or <structfield>index</structfield>
is out of bounds or the <structfield>type</structfield> field is wrong.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
</refentry>

7
Documentation/DocBook/media/v4l/vidioc-g-frequency.xml
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@ -98,11 +98,12 @@ the &v4l2-output; <structfield>modulator</structfield> field and the
<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 The type must be set
&v4l2-tuner; <structfield>type</structfield> field. The type must be set
to <constant>V4L2_TUNER_RADIO</constant> for <filename>/dev/radioX</filename>
device nodes, and to <constant>V4L2_TUNER_ANALOG_TV</constant>
for all others. The field is not applicable to modulators, &ie; ignored
by drivers. See <xref linkend="v4l2-tuner-type" /></entry>
for all others. Set this field to <constant>V4L2_TUNER_RADIO</constant> for
modulators (currently only radio modulators are supported).
See <xref linkend="v4l2-tuner-type" /></entry>
</row>
<row>
<entry>__u32</entry>

26
Documentation/DocBook/media/v4l/vidioc-g-tuner.xml
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@ -119,10 +119,14 @@ field is not quite clear.--></para></entry>
<xref linkend="tuner-capability" />. Audio flags indicate the ability
to decode audio subprograms. They will <emphasis>not</emphasis>
change, for example with the current video standard.</para><para>When
the structure refers to a radio tuner only the
<constant>V4L2_TUNER_CAP_LOW</constant>,
<constant>V4L2_TUNER_CAP_STEREO</constant> and
<constant>V4L2_TUNER_CAP_RDS</constant> flags can be set.</para></entry>
the structure refers to a radio tuner the
<constant>V4L2_TUNER_CAP_LANG1</constant>,
<constant>V4L2_TUNER_CAP_LANG2</constant> and
<constant>V4L2_TUNER_CAP_NORM</constant> flags can't be used.</para>
<para>If multiple frequency bands are supported, then
<structfield>capability</structfield> is the union of all
<structfield>capability></structfield> fields of each &v4l2-frequency-band;.
</para></entry>
</row>
<row>
<entry>__u32</entry>
@ -130,7 +134,9 @@ the structure refers to a radio tuner only the
<entry spanname="hspan">The lowest tunable frequency in
units of 62.5 kHz, or if the <structfield>capability</structfield>
flag <constant>V4L2_TUNER_CAP_LOW</constant> is set, in units of 62.5
Hz.</entry>
Hz. If multiple frequency bands are supported, then
<structfield>rangelow</structfield> is the lowest frequency
of all the frequency bands.</entry>
</row>
<row>
<entry>__u32</entry>
@ -138,7 +144,9 @@ Hz.</entry>
<entry spanname="hspan">The highest tunable frequency in
units of 62.5 kHz, or if the <structfield>capability</structfield>
flag <constant>V4L2_TUNER_CAP_LOW</constant> is set, in units of 62.5
Hz.</entry>
Hz. If multiple frequency bands are supported, then
<structfield>rangehigh</structfield> is the highest frequency
of all the frequency bands.</entry>
</row>
<row>
<entry>__u32</entry>
@ -340,6 +348,12 @@ radio tuners.</entry>
<entry>0x0200</entry>
<entry>The RDS data is parsed by the hardware and set via controls.</entry>
</row>
<row>
<entry><constant>V4L2_TUNER_CAP_FREQ_BANDS</constant></entry>
<entry>0x0400</entry>
<entry>The &VIDIOC-ENUM-FREQ-BANDS; ioctl can be used to enumerate
the available frequency bands.</entry>
</row>
</tbody>
</tgroup>
</table>