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linux-next/Documentation/media/uapi/dvb/fe-read-signal-strength.rst
Mauro Carvalho Chehab cf8076c314 [media] docs-rst: Convert DVB uAPI to use C function references
Name all ioctl references and make them match the ioctls that
are documented. That will improve the cross-reference index,
as it will have all ioctls and syscalls there.

While here, improve the documentation, marking the deprecated
ioctls, and making the non-deprecated ones more like the rest
of the media book.

Also, add a notice for ioctls that still require documentation.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-08-22 21:23:34 -03:00

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.. -*- coding: utf-8; mode: rst -*-
.. _FE_READ_SIGNAL_STRENGTH:
***********************
FE_READ_SIGNAL_STRENGTH
***********************
Name
====
FE_READ_SIGNAL_STRENGTH
.. attention:: This ioctl is deprecated.
Synopsis
========
.. c:function:: int ioctl( int fd, FE_READ_SIGNAL_STRENGTH, uint16_t *strength)
:name: FE_READ_SIGNAL_STRENGTH
Arguments
=========
``fd``
File descriptor returned by :c:func:`open() <dvb-fe-open>`.
``strength``
The signal strength value is stored into \*strength.
Description
===========
This ioctl call returns the signal strength value for the signal
currently received by the front-end. For this command, read-only access
to the device is sufficient.
Return Value
============
On success 0 is returned, on error -1 and the ``errno`` variable is set
appropriately. The generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.