// SPDX-License-Identifier: GPL-2.0
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/*
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* The Virtual DVB 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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* The vidtv tuner should support common TV standards such as
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* DVB-T/T2/S/S2, ISDB-T and ATSC when completed.
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*
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* Copyright (C) 2020 Daniel W. S. Almeida
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*/
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#include <linux/errno.h>
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#include <linux/i2c.h>
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#include <linux/module.h>
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#include <linux/printk.h>
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#include <linux/ratelimit.h>
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#include <linux/slab.h>
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#include <linux/types.h>
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#include <media/dvb_frontend.h>
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#include "vidtv_tuner.h"
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struct vidtv_tuner_cnr_to_qual_s {
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/* attempt to use the same values as libdvbv5 */
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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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static const struct vidtv_tuner_cnr_to_qual_s vidtv_tuner_c_cnr_2_qual[] = {
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/* from libdvbv5 source code, in milli db */
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{ QAM_256, FEC_NONE, 34000, 38000},
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{ QAM_64, FEC_NONE, 30000, 34000},
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};
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static const struct vidtv_tuner_cnr_to_qual_s vidtv_tuner_s_cnr_2_qual[] = {
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/* from libdvbv5 source code, in milli db */
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{ QPSK, FEC_1_2, 7000, 10000},
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{ QPSK, FEC_2_3, 9000, 12000},
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{ QPSK, FEC_3_4, 10000, 13000},
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{ QPSK, FEC_5_6, 11000, 14000},
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{ QPSK, FEC_7_8, 12000, 15000},
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};
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static const struct vidtv_tuner_cnr_to_qual_s vidtv_tuner_s2_cnr_2_qual[] = {
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/* from libdvbv5 source code, in milli db */
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{ QPSK, FEC_1_2, 9000, 12000},
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{ QPSK, FEC_2_3, 11000, 14000},
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{ QPSK, FEC_3_4, 12000, 15000},
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{ QPSK, FEC_5_6, 12000, 15000},
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{ QPSK, FEC_8_9, 13000, 16000},
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{ QPSK, FEC_9_10, 13500, 16500},
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{ PSK_8, FEC_2_3, 14500, 17500},
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{ PSK_8, FEC_3_4, 16000, 19000},
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{ PSK_8, FEC_5_6, 17500, 20500},
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{ PSK_8, FEC_8_9, 19000, 22000},
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};
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static const struct vidtv_tuner_cnr_to_qual_s vidtv_tuner_t_cnr_2_qual[] = {
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/* from libdvbv5 source code, in milli db*/
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{ QPSK, FEC_1_2, 4100, 5900},
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{ QPSK, FEC_2_3, 6100, 9600},
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{ QPSK, FEC_3_4, 7200, 12400},
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{ QPSK, FEC_5_6, 8500, 15600},
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{ QPSK, FEC_7_8, 9200, 17500},
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{ QAM_16, FEC_1_2, 9800, 11800},
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{ QAM_16, FEC_2_3, 12100, 15300},
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{ QAM_16, FEC_3_4, 13400, 18100},
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{ QAM_16, FEC_5_6, 14800, 21300},
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{ QAM_16, FEC_7_8, 15700, 23600},
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{ QAM_64, FEC_1_2, 14000, 16000},
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{ QAM_64, FEC_2_3, 19900, 25400},
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{ QAM_64, FEC_3_4, 24900, 27900},
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{ QAM_64, FEC_5_6, 21300, 23300},
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{ QAM_64, FEC_7_8, 22000, 24000},
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};
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/**
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* struct vidtv_tuner_hardware_state - Simulate the tuner hardware status
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* @asleep: whether the tuner is asleep, i.e whether _sleep() or _suspend() was
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* called.
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* @lock_status: Whether the tuner has managed to lock on the requested
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* frequency.
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* @if_frequency: The tuner's intermediate frequency. Hardcoded for the purposes
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* of simulation.
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* @tuned_frequency: The actual tuned frequency.
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* @bandwidth: The actual bandwidth.
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*
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* This structure is meant to simulate the status of the tuner hardware, as if
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* we had a physical tuner hardware.
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*/
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struct vidtv_tuner_hardware_state {
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bool asleep;
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u32 lock_status;
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u32 if_frequency;
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u32 tuned_frequency;
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u32 bandwidth;
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};
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/**
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* struct vidtv_tuner_dev - The tuner struct
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* @fe: A pointer to the dvb_frontend structure allocated by vidtv_demod
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* @hw_state: A struct to simulate the tuner's hardware state as if we had a
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* physical tuner hardware.
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* @config: The configuration used to start the tuner 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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* tuner module is probed.
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*/
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struct vidtv_tuner_dev {
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struct dvb_frontend *fe;
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struct vidtv_tuner_hardware_state hw_state;
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struct vidtv_tuner_config config;
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};
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static struct vidtv_tuner_dev*
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vidtv_tuner_get_dev(struct dvb_frontend *fe)
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{
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return i2c_get_clientdata(fe->tuner_priv);
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}
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static int vidtv_tuner_check_frequency_shift(struct dvb_frontend *fe)
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{
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struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
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struct dtv_frontend_properties *c = &fe->dtv_property_cache;
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struct vidtv_tuner_config config = tuner_dev->config;
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u32 *valid_freqs = NULL;
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u32 array_sz = 0;
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u32 i;
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u32 shift;
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switch (c->delivery_system) {
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case SYS_DVBT:
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case SYS_DVBT2:
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valid_freqs = config.vidtv_valid_dvb_t_freqs;
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array_sz = ARRAY_SIZE(config.vidtv_valid_dvb_t_freqs);
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break;
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case SYS_DVBS:
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case SYS_DVBS2:
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valid_freqs = config.vidtv_valid_dvb_s_freqs;
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array_sz = ARRAY_SIZE(config.vidtv_valid_dvb_s_freqs);
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break;
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case SYS_DVBC_ANNEX_A:
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valid_freqs = config.vidtv_valid_dvb_c_freqs;
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array_sz = ARRAY_SIZE(config.vidtv_valid_dvb_c_freqs);
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break;
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default:
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dev_warn(fe->dvb->device,
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"%s: unsupported delivery system: %u\n",
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__func__,
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c->delivery_system);
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return -EINVAL;
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}
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for (i = 0; i < array_sz; i++) {
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if (!valid_freqs[i])
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break;
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shift = abs(c->frequency - valid_freqs[i]);
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if (!shift)
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return 0;
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/*
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* This will provide a value from 0 to 100 that would
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* indicate how far is the tuned frequency from the
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* right one.
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*/
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if (shift < config.max_frequency_shift_hz)
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return shift * 100 / config.max_frequency_shift_hz;
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}
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return -EINVAL;
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}
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static int
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vidtv_tuner_get_signal_strength(struct dvb_frontend *fe, u16 *strength)
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{
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struct dtv_frontend_properties *c = &fe->dtv_property_cache;
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struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
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const struct vidtv_tuner_cnr_to_qual_s *cnr2qual = NULL;
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struct device *dev = fe->dvb->device;
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u32 array_size = 0;
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s32 shift;
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u32 i;
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shift = vidtv_tuner_check_frequency_shift(fe);
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if (shift < 0) {
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tuner_dev->hw_state.lock_status = 0;
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*strength = 0;
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return 0;
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}
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switch (c->delivery_system) {
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case SYS_DVBT:
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case SYS_DVBT2:
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cnr2qual = vidtv_tuner_t_cnr_2_qual;
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array_size = ARRAY_SIZE(vidtv_tuner_t_cnr_2_qual);
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break;
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case SYS_DVBS:
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cnr2qual = vidtv_tuner_s_cnr_2_qual;
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array_size = ARRAY_SIZE(vidtv_tuner_s_cnr_2_qual);
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break;
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case SYS_DVBS2:
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cnr2qual = vidtv_tuner_s2_cnr_2_qual;
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array_size = ARRAY_SIZE(vidtv_tuner_s2_cnr_2_qual);
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break;
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case SYS_DVBC_ANNEX_A:
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cnr2qual = vidtv_tuner_c_cnr_2_qual;
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array_size = ARRAY_SIZE(vidtv_tuner_c_cnr_2_qual);
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break;
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default:
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dev_warn_ratelimited(dev,
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"%s: unsupported delivery system: %u\n",
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__func__,
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c->delivery_system);
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return -EINVAL;
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}
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for (i = 0; i < array_size; i++) {
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if (cnr2qual[i].modulation != c->modulation ||
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cnr2qual[i].fec != c->fec_inner)
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continue;
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if (!shift) {
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*strength = cnr2qual[i].cnr_good;
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return 0;
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}
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/*
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* Channel tuned at wrong frequency. Simulate that the
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* Carrier S/N ratio is not too good.
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*/
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*strength = cnr2qual[i].cnr_ok -
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(cnr2qual[i].cnr_good - cnr2qual[i].cnr_ok);
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return 0;
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}
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/*
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* do a linear interpolation between 34dB and 10dB if we can't
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* match against the table
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*/
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*strength = 34000 - 24000 * shift / 100;
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return 0;
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}
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static int vidtv_tuner_init(struct dvb_frontend *fe)
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{
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struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
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struct vidtv_tuner_config config = tuner_dev->config;
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msleep_interruptible(config.mock_power_up_delay_msec);
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tuner_dev->hw_state.asleep = false;
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tuner_dev->hw_state.if_frequency = 5000;
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return 0;
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}
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static int vidtv_tuner_sleep(struct dvb_frontend *fe)
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{
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struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
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tuner_dev->hw_state.asleep = true;
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return 0;
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}
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static int vidtv_tuner_suspend(struct dvb_frontend *fe)
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{
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struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
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tuner_dev->hw_state.asleep = true;
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return 0;
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}
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static int vidtv_tuner_resume(struct dvb_frontend *fe)
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{
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struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
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tuner_dev->hw_state.asleep = false;
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return 0;
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}
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static int vidtv_tuner_set_params(struct dvb_frontend *fe)
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{
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struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
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struct vidtv_tuner_config config = tuner_dev->config;
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struct dtv_frontend_properties *c = &fe->dtv_property_cache;
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s32 shift;
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u32 min_freq = fe->ops.tuner_ops.info.frequency_min_hz;
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u32 max_freq = fe->ops.tuner_ops.info.frequency_max_hz;
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u32 min_bw = fe->ops.tuner_ops.info.bandwidth_min;
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u32 max_bw = fe->ops.tuner_ops.info.bandwidth_max;
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if (c->frequency < min_freq || c->frequency > max_freq ||
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c->bandwidth_hz < min_bw || c->bandwidth_hz > max_bw) {
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tuner_dev->hw_state.lock_status = 0;
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return -EINVAL;
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}
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tuner_dev->hw_state.tuned_frequency = c->frequency;
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tuner_dev->hw_state.bandwidth = c->bandwidth_hz;
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tuner_dev->hw_state.lock_status = TUNER_STATUS_LOCKED;
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msleep_interruptible(config.mock_tune_delay_msec);
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shift = vidtv_tuner_check_frequency_shift(fe);
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if (shift < 0) {
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tuner_dev->hw_state.lock_status = 0;
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return shift;
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}
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return 0;
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}
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static int vidtv_tuner_set_config(struct dvb_frontend *fe,
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void *priv_cfg)
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{
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struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
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memcpy(&tuner_dev->config, priv_cfg, sizeof(tuner_dev->config));
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return 0;
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}
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static int vidtv_tuner_get_frequency(struct dvb_frontend *fe,
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u32 *frequency)
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{
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struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
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*frequency = tuner_dev->hw_state.tuned_frequency;
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return 0;
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}
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static int vidtv_tuner_get_bandwidth(struct dvb_frontend *fe,
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u32 *bandwidth)
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{
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struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
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*bandwidth = tuner_dev->hw_state.bandwidth;
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return 0;
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}
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static int vidtv_tuner_get_if_frequency(struct dvb_frontend *fe,
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u32 *frequency)
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{
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struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
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*frequency = tuner_dev->hw_state.if_frequency;
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return 0;
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}
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static int vidtv_tuner_get_status(struct dvb_frontend *fe, u32 *status)
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{
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struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
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*status = tuner_dev->hw_state.lock_status;
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return 0;
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}
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static const struct dvb_tuner_ops vidtv_tuner_ops = {
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.init = vidtv_tuner_init,
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.sleep = vidtv_tuner_sleep,
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.suspend = vidtv_tuner_suspend,
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.resume = vidtv_tuner_resume,
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.set_params = vidtv_tuner_set_params,
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.set_config = vidtv_tuner_set_config,
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.get_bandwidth = vidtv_tuner_get_bandwidth,
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.get_frequency = vidtv_tuner_get_frequency,
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.get_if_frequency = vidtv_tuner_get_if_frequency,
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.get_status = vidtv_tuner_get_status,
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.get_rf_strength = vidtv_tuner_get_signal_strength
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};
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static const struct i2c_device_id vidtv_tuner_i2c_id_table[] = {
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{"dvb_vidtv_tuner", 0},
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{}
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};
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MODULE_DEVICE_TABLE(i2c, vidtv_tuner_i2c_id_table);
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static int vidtv_tuner_i2c_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct vidtv_tuner_config *config = client->dev.platform_data;
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struct dvb_frontend *fe = config->fe;
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struct vidtv_tuner_dev *tuner_dev = NULL;
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tuner_dev = kzalloc(sizeof(*tuner_dev), GFP_KERNEL);
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if (!tuner_dev)
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return -ENOMEM;
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tuner_dev->fe = config->fe;
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i2c_set_clientdata(client, tuner_dev);
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memcpy(&fe->ops.tuner_ops,
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&vidtv_tuner_ops,
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sizeof(struct dvb_tuner_ops));
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memcpy(&tuner_dev->config, config, sizeof(tuner_dev->config));
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fe->tuner_priv = client;
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return 0;
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}
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static int vidtv_tuner_i2c_remove(struct i2c_client *client)
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{
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struct vidtv_tuner_dev *tuner_dev = i2c_get_clientdata(client);
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kfree(tuner_dev);
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return 0;
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}
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static struct i2c_driver vidtv_tuner_i2c_driver = {
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.driver = {
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.name = "dvb_vidtv_tuner",
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.suppress_bind_attrs = true,
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},
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.probe = vidtv_tuner_i2c_probe,
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.remove = vidtv_tuner_i2c_remove,
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.id_table = vidtv_tuner_i2c_id_table,
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};
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module_i2c_driver(vidtv_tuner_i2c_driver);
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MODULE_DESCRIPTION("Virtual DVB Tuner");
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MODULE_AUTHOR("Daniel W. S. Almeida");
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MODULE_LICENSE("GPL");
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