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Diffstat (limited to 'v4l2-spec/func-open.sgml')
| -rw-r--r-- | v4l2-spec/func-open.sgml | 121 |
1 files changed, 0 insertions, 121 deletions
diff --git a/v4l2-spec/func-open.sgml b/v4l2-spec/func-open.sgml deleted file mode 100644 index 7595d07a8..000000000 --- a/v4l2-spec/func-open.sgml +++ /dev/null @@ -1,121 +0,0 @@ -<refentry id="func-open"> - <refmeta> - <refentrytitle>V4L2 open()</refentrytitle> - &manvol; - </refmeta> - - <refnamediv> - <refname>v4l2-open</refname> - <refpurpose>Open a V4L2 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 and the &VIDIOC-DQBUF; ioctl will return -the &EAGAIN; when no data is available or no buffer is in the driver -outgoing queue, otherwise these functions block until data becomes -available. All V4L2 drivers exchanging data with applications must -support the <constant>O_NONBLOCK</constant> flag.</para> - <para>Other flags have no effect.</para> - </listitem> - </varlistentry> - </variablelist> - </refsect1> - <refsect1> - <title>Description</title> - - <para>To open a V4L2 device applications call -<function>open()</function> with the desired device name. This -function has no side effects; all data format parameters, current -input or output, control values or other properties remain unchanged. -At the first <function>open()</function> call after loading the driver -they will be reset to default values, drivers are never in an -undefined state.</para> - </refsect1> - <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> - -<!-- -Local Variables: -mode: sgml -sgml-parent-document: "v4l2.sgml" -indent-tabs-mode: nil -End: ---> |