linuxdebug/Documentation/userspace-api/media/dvb/fe-read-snr.rst

50 lines
852 B
ReStructuredText
Raw Normal View History

2024-07-16 15:50:57 +02:00
.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
.. c:namespace:: DTV.fe
.. _FE_READ_SNR:
***********
FE_READ_SNR
***********
Name
====
FE_READ_SNR
.. attention:: This ioctl is deprecated.
Synopsis
========
.. c:macro:: FE_READ_SNR
``int ioctl(int fd, FE_READ_SNR, int16_t *snr)``
Arguments
=========
``fd``
File descriptor returned by :c:func:`open()`.
``snr``
The signal-to-noise ratio is stored into \*snr.
Description
===========
This ioctl call returns the signal-to-noise ratio 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 is returned, and the ``errno`` variable is set
appropriately.
Generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.