linux_dsm_epyc7002/Documentation/userspace-api/media/dvb/fe-get-frontend.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
.. _FE_GET_FRONTEND:
***************
FE_GET_FRONTEND
***************
Name
====
FE_GET_FRONTEND
.. attention:: This ioctl is deprecated.
Synopsis
========
.. c:function:: int ioctl(int fd, FE_GET_FRONTEND, struct dvb_frontend_parameters *p)
:name: FE_GET_FRONTEND
Arguments
=========
``fd``
File descriptor returned by :c:func:`open() <dvb-fe-open>`.
``p``
Points to parameters for tuning operation.
Description
===========
This ioctl call queries the currently effective frontend parameters. For
this command, read-only access to the device is sufficient.
Return Value
============
On success 0 is returned.
On error -1 is returned, and the ``errno`` variable is set
appropriately.
.. flat-table::
:header-rows: 0
:stub-columns: 0
- .. row 1
- ``EINVAL``
- Maximum supported symbol rate reached.
Generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.