<para>The DVB frontend API was designed to support three types of delivery systems:</para>
<itemizedlist>
- <listitem>Terrestrial systems: DVB-T, DVB-T2, ATSC, ATSC M/H, ISDB-T, DVB-H, DTMB, CMMB</listitem>
- <listitem>Cable systems: DVB-C Annex A/C, ClearQAM (DVB-C Annex B), ISDB-C</listitem>
- <listitem>Satellital systems: DVB-S, DVB-S2, DVB Turbo, ISDB-S, DSS</listitem>
+ <listitem><para>Terrestrial systems: DVB-T, DVB-T2, ATSC, ATSC M/H, ISDB-T, DVB-H, DTMB, CMMB</para></listitem>
+ <listitem><para>Cable systems: DVB-C Annex A/C, ClearQAM (DVB-C Annex B), ISDB-C</para></listitem>
+ <listitem><para>Satellite systems: DVB-S, DVB-S2, DVB Turbo, ISDB-S, DSS</para></listitem>
</itemizedlist>
<para>The DVB frontend controls several sub-devices including:</para>
<itemizedlist>
- <listitem>Tuner</listitem>,
- <listitem>Digital TV demodulator</listitem>
- <listitem>Low noise amplifier (LNA)</listitem>
- <listitem>Satellite Equipment Control (SEC) hardware (only for Satellite).</listitem>
+ <listitem><para>Tuner</para></listitem>
+ <listitem><para>Digital TV demodulator</para></listitem>
+ <listitem><para>Low noise amplifier (LNA)</para></listitem>
+ <listitem><para>Satellite Equipment Control (SEC) hardware (only for Satellite).</para></listitem>
</itemizedlist>
<para>The frontend can be accessed through
- <emphasis role="bold">/dev/dvb/adapter?/frontend?</emphasis>. Data types and
+ <constant>/dev/dvb/adapter?/frontend?</constant>. Data types and
ioctl definitions can be accessed by including
- <emphasis role="bold">linux/dvb/frontend.h</emphasis> in your application.
+ <constant>linux/dvb/frontend.h</constant> in your application.
</para>
<para>NOTE: Transmission via the internet (DVB-IP)
is not yet handled by this API but a future extension is possible.</para>
-<para>On Satellital systems, the API support for the Satellite Equipment Control
+<para>On Satellite systems, the API support for the Satellite Equipment Control
(SEC) allows to power control and to send/receive signals to control the
antenna subsystem, selecting the polarization and choosing the Intermediate
Frequency IF) of the Low Noise Block Converter Feed Horn (LNBf). It
<para>The information about the frontend tuner locking status can be queried
using <link linkend="FE_READ_STATUS">FE_READ_STATUS</link>.</para>
<para>Signal statistics are provided via <link linkend="FE_GET_PROPERTY"><constant>FE_GET_PROPERTY</constant></link>.
- Please notice that several statistics require the demodulator to be fully
+ Please note that several statistics require the demodulator to be fully
locked (e. g. with FE_HAS_LOCK bit set). See
- <xref linkend="frontend-stat-properties">Frontend statistics indicators</xref>
+ <link linkend="frontend-stat-properties">Frontend statistics indicators</link>
for more details.</para>
</section>
&sub-dvbproperty;
-<section>
-<title>More OFDM parameters</title>
+<section id="frontend_fcalls">
+<title>Frontend Function Calls</title>
-<section id="fe-guard-interval-t">
-<title>frontend guard inverval</title>
-<programlisting>
-typedef enum fe_guard_interval {
- GUARD_INTERVAL_1_32,
- GUARD_INTERVAL_1_16,
- GUARD_INTERVAL_1_8,
- GUARD_INTERVAL_1_4,
- GUARD_INTERVAL_AUTO,
- GUARD_INTERVAL_1_128,
- GUARD_INTERVAL_19_128,
- GUARD_INTERVAL_19_256,
-} fe_guard_interval_t;
-</programlisting>
-</section>
+<refentry id="frontend_f_open">
+ <refmeta>
+ <refentrytitle>DVB frontend open()</refentrytitle>
+ &manvol;
+ </refmeta>
-<section id="fe-hierarchy-t">
-<title>frontend hierarchy</title>
-<programlisting>
-typedef enum fe_hierarchy {
- HIERARCHY_NONE,
- HIERARCHY_1,
- HIERARCHY_2,
- HIERARCHY_4,
- HIERARCHY_AUTO
- } fe_hierarchy_t;
-</programlisting>
-</section>
+ <refnamediv>
+ <refname>fe-open</refname>
+ <refpurpose>Open a frontend device</refpurpose>
+ </refnamediv>
-</section>
+ <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>
-<section id="frontend_fcalls">
-<title>Frontend Function Calls</title>
+ <refsect1>
+ <title>Arguments</title>
-<section id="frontend_f_open">
-<title>open()</title>
-<para>DESCRIPTION</para>
-<informaltable><tgroup cols="1"><tbody><row>
-<entry align="char">
-<para>This system call opens a named frontend device (/dev/dvb/adapter0/frontend0)
+ <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 can either be
+ <constant>O_RDWR</constant> or <constant>O_RDONLY</constant>.</para>
+ <para>Multiple opens are allowed with <constant>O_RDONLY</constant>. In this mode, only query and read ioctls are allowed.</para>
+ <para>Only one open is allowed in <constant>O_RDWR</constant>. In this mode, all ioctls are allowed.</para>
+ <para>When the <constant>O_NONBLOCK</constant> flag is given, the system calls may return &EAGAIN; when no data is available or when the device driver is temporarily busy.</para>
+ <para>Other flags have no effect.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>This system call opens a named frontend device (<constant>/dev/dvb/adapter?/frontend?</constant>)
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>
<para>The device can be opened in read-only mode, which only allows monitoring of
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 the device driver 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>
+ <varlistentry>
+ <term><errorcode>ENODEV</errorcode></term>
+ <listitem>
+ <para>The device got removed.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+</refentry>
+
+<refentry id="frontend_f_close">
+ <refmeta>
+ <refentrytitle>DVB frontend 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;
projects / cascardo / linux.git / blobdiff