[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: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
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		|  | @ -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 <fcntl.h></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> | ||||
|   </refsect1> | ||||
| 
 | ||||
| <para>SYNOPSIS</para> | ||||
| <informaltable><tgroup cols="1"><tbody><row><entry | ||||
|  align="char"> | ||||
| <para>int open(const char ⋆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> | ||||
|     <title>Return Value</title> | ||||
| 
 | ||||
| <section id="frontend_f_close"> | ||||
| <title>close()</title> | ||||
| <para>DESCRIPTION | ||||
| </para> | ||||
| <informaltable><tgroup cols="1"><tbody><row><entry | ||||
|  align="char"> | ||||
|     <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 <unistd.h></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; | ||||
|  |  | |||
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