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