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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/userspace-api/media/dvb/ca-fopen.rst | |
parent | Initial commit. (diff) | |
download | linux-upstream/5.10.209.tar.xz linux-upstream/5.10.209.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/userspace-api/media/dvb/ca-fopen.rst')
-rw-r--r-- | Documentation/userspace-api/media/dvb/ca-fopen.rst | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/dvb/ca-fopen.rst b/Documentation/userspace-api/media/dvb/ca-fopen.rst new file mode 100644 index 000000000..7f99908ff --- /dev/null +++ b/Documentation/userspace-api/media/dvb/ca-fopen.rst @@ -0,0 +1,72 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: DTV.ca + +.. _ca_fopen: + +==================== +Digital TV CA open() +==================== + +Name +---- + +Digital TV CA open() + +Synopsis +-------- + +.. c:function:: int open(const char *name, int flags) + +Arguments +--------- + +``name`` + Name of specific Digital TV CA device. + +``flags`` + A bit-wise OR of the following flags: + +.. tabularcolumns:: |p{2.5cm}|p{15.0cm}| + +.. flat-table:: + :header-rows: 0 + :stub-columns: 0 + :widths: 1 16 + + - - ``O_RDONLY`` + - read-only access + + - - ``O_RDWR`` + - read/write access + + - - ``O_NONBLOCK`` + - open in non-blocking mode + (blocking mode is the default) + +Description +----------- + +This system call opens a named ca device (e.g. ``/dev/dvb/adapter?/ca?``) +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 CA Device in ``O_RDWR`` mode. All other +attempts to open the device in this mode will fail, and an error code +will be returned. + +Return Value +------------ + +On success 0 is returned. + +On error -1 is returned, and the ``errno`` variable is set +appropriately. + +Generic error codes are described at the +:ref:`Generic Error Codes <gen-errors>` chapter. |