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diff --git a/drivers/media/test-drivers/vidtv/vidtv_demod.h b/drivers/media/test-drivers/vidtv/vidtv_demod.h
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+/* 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 <emard@softhome.net>
+ */
+
+#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