| 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
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| 2 | /* |
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| 3 | * The Virtual DTV test driver serves as a reference DVB driver and helps |
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| 4 | * validate the existing APIs in the media subsystem. It can also aid |
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| 5 | * developers working on userspace applications. |
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| 6 | * |
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| 7 | * Copyright (C) 2020 Daniel W. S. Almeida |
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| 8 | * Based on the example driver written by Emard <emard@softhome.net> |
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| 9 | */ |
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| 10 | |
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| 11 | #ifndef VIDTV_DEMOD_H |
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| 12 | #define VIDTV_DEMOD_H |
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| 13 | |
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| 14 | #include <linux/dvb/frontend.h> |
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| 15 | |
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| 16 | #include <media/dvb_frontend.h> |
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| 17 | |
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| 18 | /** |
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| 19 | * struct vidtv_demod_cnr_to_qual_s - Map CNR values to a given combination of |
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| 20 | * modulation and fec_inner |
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| 21 | * @modulation: see enum fe_modulation |
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| 22 | * @fec: see enum fe_fec_rate |
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| 23 | * @cnr_ok: S/N threshold to consider the signal as OK. Below that, there's |
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| 24 | * a chance of losing sync. |
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| 25 | * @cnr_good: S/N threshold to consider the signal strong. |
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| 26 | * |
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| 27 | * This struct matches values for 'good' and 'ok' CNRs given the combination |
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| 28 | * of modulation and fec_inner in use. We might simulate some noise if the |
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| 29 | * signal quality is not too good. |
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| 30 | * |
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| 31 | * The values were taken from libdvbv5. |
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| 32 | */ |
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| 33 | struct vidtv_demod_cnr_to_qual_s { |
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| 34 | u32 modulation; |
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| 35 | u32 fec; |
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| 36 | u32 cnr_ok; |
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| 37 | u32 cnr_good; |
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| 38 | }; |
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| 39 | |
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| 40 | /** |
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| 41 | * struct vidtv_demod_config - Configuration used to init the demod |
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| 42 | * @drop_tslock_prob_on_low_snr: probability of losing the lock due to low snr |
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| 43 | * @recover_tslock_prob_on_good_snr: probability of recovering when the signal |
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| 44 | * improves |
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| 45 | * |
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| 46 | * The configuration used to init the demodulator module, usually filled |
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| 47 | * by a bridge driver. For vidtv, this is filled by vidtv_bridge before the |
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| 48 | * demodulator module is probed. |
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| 49 | */ |
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| 50 | struct vidtv_demod_config { |
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| 51 | u8 drop_tslock_prob_on_low_snr; |
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| 52 | u8 recover_tslock_prob_on_good_snr; |
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| 53 | }; |
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| 54 | |
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| 55 | /** |
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| 56 | * struct vidtv_demod_state - The demodulator state |
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| 57 | * @frontend: The frontend structure allocated by the demod. |
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| 58 | * @config: The config used to init the demod. |
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| 59 | * @status: the demod status. |
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| 60 | * @tuner_cnr: current S/N ratio for the signal carrier |
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| 61 | */ |
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| 62 | struct vidtv_demod_state { |
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| 63 | struct dvb_frontend frontend; |
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| 64 | struct vidtv_demod_config config; |
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| 65 | enum fe_status status; |
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| 66 | u16 tuner_cnr; |
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| 67 | }; |
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| 68 | #endif // VIDTV_DEMOD_H |
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| 69 | |
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