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Diffstat (limited to 'Documentation/media/uapi/dvb/fe-read-snr.rst')
-rw-r--r-- | Documentation/media/uapi/dvb/fe-read-snr.rst | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/Documentation/media/uapi/dvb/fe-read-snr.rst b/Documentation/media/uapi/dvb/fe-read-snr.rst new file mode 100644 index 000000000000..5394f9ae90f4 --- /dev/null +++ b/Documentation/media/uapi/dvb/fe-read-snr.rst @@ -0,0 +1,61 @@ +.. -*- coding: utf-8; mode: rst -*- + +.. _FE_READ_SNR: + +*********** +FE_READ_SNR +*********** + +Name +==== + +FE_READ_SNR + + +Synopsis +======== + +.. cpp:function:: int ioctl(int fd, int request = FE_READ_SNR, int16_t *snr) + + +Arguments +========= + +.. flat-table:: + :header-rows: 0 + :stub-columns: 0 + + + - .. row 1 + + - int fd + + - File descriptor returned by a previous call to open(). + + - .. row 2 + + - int request + + - Equals :ref:`FE_READ_SNR` for this command. + + - .. row 3 + + - uint16_t \*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 and the ``errno`` variable is set +appropriately. The generic error codes are described at the +:ref:`Generic Error Codes <gen-errors>` chapter. |