linux/Documentation/userspace-api/media/dvb/video-fopen.rst
Mauro Carvalho Chehab 54f38fcae5 media: docs: move uAPI book to userspace-api/media
Since 2017, there is an space reserved for userspace API,
created by changeset 1d596dee38 ("docs: Create a user-space API guide").

As the media subsystem was one of the first subsystems to use
Sphinx, until this patch, we were keeping things on a separate
place.

Let's just use the new location, as having all uAPI altogether
will likely make things easier for developers.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-04-14 10:31:49 +02:00

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.. Permission is granted to copy, distribute and/or modify this
.. document under the terms of the GNU Free Documentation License,
.. Version 1.1 or any later version published by the Free Software
.. Foundation, with no Invariant Sections, no Front-Cover Texts
.. and no Back-Cover Texts. A copy of the license is included at
.. Documentation/userspace-api/media/fdl-appendix.rst.
..
.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
.. _video_fopen:
================
dvb video open()
================
Name
----
dvb video open()
.. attention:: This ioctl is deprecated.
Synopsis
--------
.. c:function:: int open(const char *deviceName, int flags)
Arguments
---------
.. flat-table::
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:stub-columns: 0
- .. row 1
- const char \*deviceName
- Name of specific video device.
- .. row 2
- int flags
- A bit-wise OR of the following flags:
- .. row 3
-
- O_RDONLY read-only access
- .. row 4
-
- O_RDWR read/write access
- .. row 5
-
- O_NONBLOCK open in non-blocking mode
- .. row 6
-
- (blocking mode is the default)
Description
-----------
This system call opens a named video device (e.g.
/dev/dvb/adapter0/video0) for subsequent use.
When an open() call has succeeded, the device will be ready for use. The
significance of blocking or non-blocking mode is described in the
documentation for functions where there is a difference. It does not
affect the semantics of the open() call itself. A device opened in
blocking mode can later be put into non-blocking mode (and vice versa)
using the F_SETFL command of the fcntl system call. This is a standard
system call, documented in the Linux manual page for fcntl. Only one
user can open the Video Device in O_RDWR mode. All other attempts to
open the device in this mode will fail, and an error-code will be
returned. If the Video Device is opened in O_RDONLY mode, the only
ioctl call that can be used is VIDEO_GET_STATUS. All other call will
return an error code.
Return Value
------------
.. tabularcolumns:: |p{2.5cm}|p{15.0cm}|
.. flat-table::
:header-rows: 0
:stub-columns: 0
- .. row 1
- ``ENODEV``
- Device driver not loaded/available.
- .. row 2
- ``EINTERNAL``
- Internal error.
- .. row 3
- ``EBUSY``
- Device or resource busy.
- .. row 4
- ``EINVAL``
- Invalid argument.