0001 .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
0002 .. c:namespace:: DTV.fe
0003
0004 .. _FE_READ_SNR:
0005
0006 ***********
0007 FE_READ_SNR
0008 ***********
0009
0010 Name
0011 ====
0012
0013 FE_READ_SNR
0014
0015 .. attention:: This ioctl is deprecated.
0016
0017 Synopsis
0018 ========
0019
0020 .. c:macro:: FE_READ_SNR
0021
0022 ``int ioctl(int fd, FE_READ_SNR, int16_t *snr)``
0023
0024 Arguments
0025 =========
0026
0027 ``fd``
0028 File descriptor returned by :c:func:`open()`.
0029
0030 ``snr``
0031 The signal-to-noise ratio is stored into \*snr.
0032
0033 Description
0034 ===========
0035
0036 This ioctl call returns the signal-to-noise ratio for the signal
0037 currently received by the front-end. For this command, read-only access
0038 to the device is sufficient.
0039
0040 Return Value
0041 ============
0042
0043 On success 0 is returned.
0044
0045 On error -1 is returned, and the ``errno`` variable is set
0046 appropriately.
0047
0048 Generic error codes are described at the
0049 :ref:`Generic Error Codes <gen-errors>` chapter.