Documentation/userspace-api/media/mediactl/media-func-open.rst

Source file repositories/reference/linux-study-clean/Documentation/userspace-api/media/mediactl/media-func-open.rst

File Facts

System: Linux kernel
Corpus path: Documentation/userspace-api/media/mediactl/media-func-open.rst
Extension: .rst
Size: 1339 bytes
Lines: 66
Domain: Support Tooling And Documentation
Bucket: Documentation
Inferred role: Support Tooling And Documentation: documentation
Status: atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

fcntl.h

Detected Declarations

No top-level syscall, struct, function, initcall, or export declaration detected by the generator.

Annotated Snippet

.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
.. c:namespace:: MC

.. _media-func-open:

************
media open()
************

Name
====

media-open - Open a media device

Synopsis
========

.. code-block:: c

    #include <fcntl.h>

.. c:function:: int open( const char *device_name, int flags )

Arguments
=========

``device_name``
    Device to be opened.

``flags``
    Open flags. Access mode must be either ``O_RDONLY`` or ``O_RDWR``.
    Other flags have no effect.

Description
===========

To open a media device applications call :c:func:`open()` with the
desired device name. The function has no side effects; the device
configuration remain unchanged.

When the device is opened in read-only mode, attempts to modify its
configuration will result in an error, and ``errno`` will be set to
EBADF.

Return Value
============

:c:func:`open()` returns the new file descriptor on success. On error,
-1 is returned, and ``errno`` is set appropriately. Possible error codes
are:

EACCES
    The requested access to the file is not allowed.

EMFILE
    The process already has the maximum number of files open.

ENFILE
    The system limit on the total number of open files has been reached.

ENOMEM
    Insufficient kernel memory was available.

ENXIO
    No device corresponding to this device special file exists.

Annotation

Immediate include surface: `fcntl.h`.
Atlas domain: Support Tooling And Documentation / Documentation.
Implementation status: atlas-only.

Implementation Notes

This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.