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Diffstat (limited to 'Documentation/DocBook/v4l/media-func-open.xml')
-rw-r--r-- | Documentation/DocBook/v4l/media-func-open.xml | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/Documentation/DocBook/v4l/media-func-open.xml b/Documentation/DocBook/v4l/media-func-open.xml new file mode 100644 index 00000000000..f7df034dc9e --- /dev/null +++ b/Documentation/DocBook/v4l/media-func-open.xml @@ -0,0 +1,94 @@ +<refentry id="media-func-open"> + <refmeta> + <refentrytitle>media open()</refentrytitle> + &manvol; + </refmeta> + + <refnamediv> + <refname>media-open</refname> + <refpurpose>Open a media 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 either <constant>O_RDONLY</constant> + or <constant>O_RDWR</constant>. Other flags have no effect.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + <refsect1> + <title>Description</title> + <para>To open a media device applications call <function>open()</function> + with the desired device name. The function has no side effects; the device + configuration remain unchanged.</para> + <para>When the device is opened in read-only mode, attemps to modify its + configuration will result in an error, and <varname>errno</varname> will be + set to <errorcode>EBADF</errorcode>.</para> + </refsect1> + <refsect1> + <title>Return Value</title> + + <para><function>open</function> returns the new file descriptor on success. + On error, -1 is returned, and <varname>errno</varname> is set appropriately. + Possible error codes are:</para> + + <variablelist> + <varlistentry> + <term><errorcode>EACCES</errorcode></term> + <listitem> + <para>The requested access to the file is not allowed.</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 system limit on the total number of open files has been + reached.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><errorcode>ENOMEM</errorcode></term> + <listitem> + <para>Insufficient kernel memory was available.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><errorcode>ENXIO</errorcode></term> + <listitem> + <para>No device corresponding to this device special file exists. + </para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> +</refentry> |