/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* The Virtual DTV test driver serves as a reference DVB driver and helps
* validate the existing APIs in the media subsystem. It can also aid
* developers working on userspace applications.
*
* Copyright (C) 2020 Daniel W. S. Almeida
* Based on the example driver written by Emard <[email protected]>
*/
#ifndef VIDTV_DEMOD_H
#define VIDTV_DEMOD_H
#include <linux/dvb/frontend.h>
#include <media/dvb_frontend.h>
/**
* struct vidtv_demod_cnr_to_qual_s - Map CNR values to a given combination of
* modulation and fec_inner
* @modulation: see enum fe_modulation
* @fec: see enum fe_fec_rate
* @cnr_ok: S/N threshold to consider the signal as OK. Below that, there's
* a chance of losing sync.
* @cnr_good: S/N threshold to consider the signal strong.
*
* This struct matches values for 'good' and 'ok' CNRs given the combination
* of modulation and fec_inner in use. We might simulate some noise if the
* signal quality is not too good.
*
* The values were taken from libdvbv5.
*/
struct vidtv_demod_cnr_to_qual_s {
u32 modulation;
u32 fec;
u32 cnr_ok;
u32 cnr_good;
};
/**
* struct vidtv_demod_config - Configuration used to init the demod
* @drop_tslock_prob_on_low_snr: probability of losing the lock due to low snr
* @recover_tslock_prob_on_good_snr: probability of recovering when the signal
* improves
*
* The configuration used to init the demodulator module, usually filled
* by a bridge driver. For vidtv, this is filled by vidtv_bridge before the
* demodulator module is probed.
*/
struct vidtv_demod_config {
u8 drop_tslock_prob_on_low_snr;
u8 recover_tslock_prob_on_good_snr;
};
/**
* struct vidtv_demod_state - The demodulator state
* @frontend: The frontend structure allocated by the demod.
* @config: The config used to init the demod.
* @status: the demod status.
* @tuner_cnr: current S/N ratio for the signal carrier
*/
struct vidtv_demod_state {
struct dvb_frontend frontend;
struct vidtv_demod_config config;
enum fe_status status;
u16 tuner_cnr;
};
#endif // VIDTV_DEMOD_H
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