Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit dc9ef7d1 authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab
Browse files

[media] DocBook media: rewrite frontend open/close 



To fix the last xmllint errors the open and close function reference
description was rewritten based on the v4l2 open and close functions.

Signed-off-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@osg.samsung.com>
parent 595d041a

Documentation/DocBook/media/dvb/frontend.xml

+159 −122
Original line number Diff line number Diff line
@@ -59,11 +59,54 @@ specification is available at 
<section id="frontend_fcalls">

<title>Frontend Function Calls</title>



<section id="frontend_f_open">

<title>open()</title>

<para>DESCRIPTION</para>

<informaltable><tgroup cols="1"><tbody><row>

<entry align="char">

<refentry id="frontend_f_open">

  <refmeta>

    <refentrytitle>open()</refentrytitle>

    &manvol;

  </refmeta>



  <refnamediv>

    <refname>fe-open</refname>

    <refpurpose>Open a frontend device</refpurpose>

  </refnamediv>



  <refsynopsisdiv>

    <funcsynopsis>

      <funcsynopsisinfo>#include &lt;fcntl.h&gt;</funcsynopsisinfo>

      <funcprototype>

	<funcdef>int <function>open</function></funcdef>

	<paramdef>const char *<parameter>device_name</parameter></paramdef>

	<paramdef>int <parameter>flags</parameter></paramdef>

      </funcprototype>

    </funcsynopsis>

  </refsynopsisdiv>



  <refsect1>

    <title>Arguments</title>



    <variablelist>

      <varlistentry>

	<term><parameter>device_name</parameter></term>

	<listitem>

	  <para>Device to be opened.</para>

	</listitem>

      </varlistentry>

      <varlistentry>

	<term><parameter>flags</parameter></term>

	<listitem>

	  <para>Open flags. Access mode must be

<constant>O_RDWR</constant>. This is just a technicality, input devices

still support only reading and output devices only writing.</para>

	  <para>When the <constant>O_NONBLOCK</constant> flag is

given, the read() function will return the &EAGAIN; when no data is available,

otherwise these functions block until data becomes

available. Other flags have no effect.</para>

	</listitem>

      </varlistentry>

    </variablelist>

  </refsect1>

  <refsect1>

    <title>Description</title>

<para>This system call opens a named frontend device (/dev/dvb/adapter0/frontend0)

 for subsequent use. Usually the first thing to do after a successful open is to

 find out the frontend type with <link linkend="FE_GET_INFO">FE_GET_INFO</link>.</para>
@@ -82,127 +125,121 @@ specification is available at 
 for use in the specified mode. This implies that the corresponding hardware is

 powered up, and that other front-ends may have been powered down to make

 that possible.</para>

</entry>

 </row></tbody></tgroup></informaltable>



<para>SYNOPSIS</para>

<informaltable><tgroup cols="1"><tbody><row><entry

 align="char">

<para>int open(const char &#x22C6;deviceName, int flags);</para>

</entry>

 </row></tbody></tgroup></informaltable>

<para>PARAMETERS

</para>

<informaltable><tgroup cols="2"><tbody><row><entry

 align="char">

<para>const char

 *deviceName</para>

</entry><entry

 align="char">

<para>Name of specific video device.</para>

</entry>

 </row><row><entry

 align="char">

<para>int flags</para>

</entry><entry

 align="char">

<para>A bit-wise OR of the following flags:</para>

</entry>

 </row><row><entry

 align="char">

</entry><entry

 align="char">

<para>O_RDONLY read-only access</para>

</entry>

 </row><row><entry

 align="char">

</entry><entry

 align="char">

<para>O_RDWR read/write access</para>

</entry>

 </row><row><entry

 align="char">

</entry><entry

 align="char">

<para>O_NONBLOCK open in non-blocking mode</para>

</entry>

 </row><row><entry

 align="char">

</entry><entry

 align="char">

<para>(blocking mode is the default)</para>

</entry>

 </row></tbody></tgroup></informaltable>

<para>RETURN VALUE</para>

<informaltable><tgroup cols="2"><tbody><row><entry

 align="char">

<para>ENODEV</para>

</entry><entry

 align="char">

<para>Device driver not loaded/available.</para>

</entry>

 </row><row><entry

 align="char">

<para>EINTERNAL</para>

</entry><entry

 align="char">

<para>Internal error.</para>

</entry>

 </row><row><entry

 align="char">

<para>EBUSY</para>

</entry><entry

 align="char">

<para>Device or resource busy.</para>

</entry>

 </row><row><entry

 align="char">

<para>EINVAL</para>

</entry><entry

 align="char">

<para>Invalid argument.</para>

</entry>

 </row></tbody></tgroup></informaltable>

</section>

  </refsect1>



<section id="frontend_f_close">

<title>close()</title>

<para>DESCRIPTION

</para>

<informaltable><tgroup cols="1"><tbody><row><entry

 align="char">

  <refsect1>

    <title>Return Value</title>



    <para>On success <function>open</function> returns the new file

descriptor. On error -1 is returned, and the <varname>errno</varname>

variable is set appropriately. Possible error codes are:</para>



    <variablelist>

      <varlistentry>

	<term><errorcode>EACCES</errorcode></term>

	<listitem>

	  <para>The caller has no permission to access the

device.</para>

	</listitem>

      </varlistentry>

      <varlistentry>

	<term><errorcode>EBUSY</errorcode></term>

	<listitem>

	  <para>The driver does not support multiple opens and the

device is already in use.</para>

	</listitem>

      </varlistentry>

      <varlistentry>

	<term><errorcode>ENXIO</errorcode></term>

	<listitem>

	  <para>No device corresponding to this device special file

exists.</para>

	</listitem>

      </varlistentry>

      <varlistentry>

	<term><errorcode>ENOMEM</errorcode></term>

	<listitem>

	  <para>Not enough kernel memory was available to complete the

request.</para>

	</listitem>

      </varlistentry>

      <varlistentry>

	<term><errorcode>EMFILE</errorcode></term>

	<listitem>

	  <para>The  process  already  has  the  maximum number of

files open.</para>

	</listitem>

      </varlistentry>

      <varlistentry>

	<term><errorcode>ENFILE</errorcode></term>

	<listitem>

	  <para>The limit on the total number of files open on the

system has been reached.</para>

	</listitem>

      </varlistentry>

    </variablelist>

  </refsect1>

</refentry>



<refentry id="frontend_f_close">

  <refmeta>

    <refentrytitle>close()</refentrytitle>

    &manvol;

  </refmeta>



  <refnamediv>

    <refname>fe-close</refname>

    <refpurpose>Close a frontend device</refpurpose>

  </refnamediv>



  <refsynopsisdiv>

    <funcsynopsis>

      <funcsynopsisinfo>#include &lt;unistd.h&gt;</funcsynopsisinfo>

      <funcprototype>

	<funcdef>int <function>close</function></funcdef>

	<paramdef>int <parameter>fd</parameter></paramdef>

      </funcprototype>

    </funcsynopsis>

  </refsynopsisdiv>



  <refsect1>

    <title>Arguments</title>



    <variablelist>

      <varlistentry>

	<term><parameter>fd</parameter></term>

	<listitem>

	  <para>&fd;</para>

	</listitem>

      </varlistentry>

    </variablelist>

  </refsect1>



  <refsect1>

    <title>Description</title>

<para>This system call closes a previously opened front-end device. After closing

 a front-end device, its corresponding hardware might be powered down

 automatically.</para>

</entry>

 </row></tbody></tgroup></informaltable>

<para>SYNOPSIS

</para>

<informaltable><tgroup cols="1"><tbody><row><entry

 align="char">

<para>int close(int fd);</para>

</entry>

 </row></tbody></tgroup></informaltable>

<para>PARAMETERS

</para>

<informaltable><tgroup cols="2"><tbody><row><entry

 align="char">

<para>int fd</para>

</entry><entry

 align="char">

<para>File descriptor returned by a previous call to open().</para>

</entry>

 </row></tbody></tgroup></informaltable>

<para>RETURN VALUE</para>

<informaltable><tgroup cols="2"><tbody><row><entry

 align="char">

<para>EBADF</para>

</entry><entry

 align="char">

<para>fd is not a valid open file descriptor.</para>

</entry>

 </row></tbody></tgroup></informaltable>

</section>

</refsect1>

  <refsect1>

    <title>Return Value</title>



    <para>The function returns <returnvalue>0</returnvalue> on

success, <returnvalue>-1</returnvalue> on failure and the

<varname>errno</varname> is set appropriately. Possible error

codes:</para>



    <variablelist>

      <varlistentry>

	<term><errorcode>EBADF</errorcode></term>

	<listitem>

	  <para><parameter>fd</parameter> is not a valid open file

descriptor.</para>

	</listitem>

      </varlistentry>

    </variablelist>

  </refsect1>

</refentry>



&sub-fe-get-info;

&sub-fe-read-status;