463 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			463 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0-or-later
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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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 * 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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#include <linux/errno.h>
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#include <linux/i2c.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/printk.h>
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#include <linux/random.h>
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#include <linux/ratelimit.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <linux/workqueue.h>
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#include <media/dvb_frontend.h>
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#include "vidtv_demod.h"
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#define POLL_THRD_TIME 2000 /* ms */
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static const struct vidtv_demod_cnr_to_qual_s vidtv_demod_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_demod_cnr_to_qual_s vidtv_demod_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_demod_cnr_to_qual_s vidtv_demod_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_demod_cnr_to_qual_s vidtv_demod_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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static const struct vidtv_demod_cnr_to_qual_s *vidtv_match_cnr_s(struct dvb_frontend *fe)
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{
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	const struct vidtv_demod_cnr_to_qual_s *cnr2qual = NULL;
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	struct device *dev = fe->dvb->device;
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	struct dtv_frontend_properties *c;
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	u32 array_size = 0;
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	u32 i;
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	c = &fe->dtv_property_cache;
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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_demod_t_cnr_2_qual;
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		array_size = ARRAY_SIZE(vidtv_demod_t_cnr_2_qual);
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		break;
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	case SYS_DVBS:
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		cnr2qual   = vidtv_demod_s_cnr_2_qual;
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		array_size = ARRAY_SIZE(vidtv_demod_s_cnr_2_qual);
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		break;
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	case SYS_DVBS2:
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		cnr2qual   = vidtv_demod_s2_cnr_2_qual;
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		array_size = ARRAY_SIZE(vidtv_demod_s2_cnr_2_qual);
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		break;
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	case SYS_DVBC_ANNEX_A:
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		cnr2qual   = vidtv_demod_c_cnr_2_qual;
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		array_size = ARRAY_SIZE(vidtv_demod_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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		break;
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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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			return &cnr2qual[i];
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	return NULL; /* not found */
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}
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static void vidtv_clean_stats(struct dvb_frontend *fe)
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{
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	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
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	/* Fill the length of each status counter */
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	/* Signal is always available */
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	c->strength.len = 1;
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	c->strength.stat[0].scale = FE_SCALE_DECIBEL;
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	c->strength.stat[0].svalue = 0;
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	/* Usually available only after Viterbi lock */
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	c->cnr.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
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	c->cnr.stat[0].svalue = 0;
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	c->cnr.len = 1;
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	/* Those depends on full lock */
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	c->pre_bit_error.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
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	c->pre_bit_error.stat[0].uvalue = 0;
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	c->pre_bit_error.len = 1;
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	c->pre_bit_count.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
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	c->pre_bit_count.stat[0].uvalue = 0;
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	c->pre_bit_count.len = 1;
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	c->post_bit_error.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
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	c->post_bit_error.stat[0].uvalue = 0;
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	c->post_bit_error.len = 1;
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	c->post_bit_count.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
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	c->post_bit_count.stat[0].uvalue = 0;
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	c->post_bit_count.len = 1;
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	c->block_error.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
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	c->block_error.stat[0].uvalue = 0;
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	c->block_error.len = 1;
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	c->block_count.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
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	c->block_count.stat[0].uvalue = 0;
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	c->block_count.len = 1;
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}
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static void vidtv_demod_update_stats(struct dvb_frontend *fe)
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{
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	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
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	struct vidtv_demod_state *state = fe->demodulator_priv;
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	u32 scale;
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	if (state->status & FE_HAS_LOCK) {
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		scale = FE_SCALE_COUNTER;
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		c->cnr.stat[0].scale = FE_SCALE_DECIBEL;
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	} else {
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		scale = FE_SCALE_NOT_AVAILABLE;
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		c->cnr.stat[0].scale = scale;
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	}
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	c->pre_bit_error.stat[0].scale = scale;
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	c->pre_bit_count.stat[0].scale = scale;
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	c->post_bit_error.stat[0].scale = scale;
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	c->post_bit_count.stat[0].scale = scale;
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	c->block_error.stat[0].scale = scale;
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	c->block_count.stat[0].scale = scale;
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	/*
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	 * Add a 0.5% of randomness at the signal strength and CNR,
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	 * and make them different, as we want to have something closer
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	 * to a real case scenario.
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	 *
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	 * Also, usually, signal strength is a negative number in dBm.
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	 */
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	c->strength.stat[0].svalue = state->tuner_cnr;
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	c->strength.stat[0].svalue -= prandom_u32_max(state->tuner_cnr / 50);
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	c->strength.stat[0].svalue -= 68000; /* Adjust to a better range */
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	c->cnr.stat[0].svalue = state->tuner_cnr;
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	c->cnr.stat[0].svalue -= prandom_u32_max(state->tuner_cnr / 50);
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}
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static int vidtv_demod_read_status(struct dvb_frontend *fe,
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				   enum fe_status *status)
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{
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	struct vidtv_demod_state *state = fe->demodulator_priv;
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	const struct vidtv_demod_cnr_to_qual_s *cnr2qual = NULL;
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	struct vidtv_demod_config *config = &state->config;
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	u16 snr = 0;
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	/* Simulate random lost of signal due to a bad-tuned channel */
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	cnr2qual = vidtv_match_cnr_s(&state->frontend);
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	if (cnr2qual && state->tuner_cnr < cnr2qual->cnr_good &&
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	    state->frontend.ops.tuner_ops.get_rf_strength) {
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		state->frontend.ops.tuner_ops.get_rf_strength(&state->frontend,
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							      &snr);
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		if (snr < cnr2qual->cnr_ok) {
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			/* eventually lose the TS lock */
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			if (prandom_u32_max(100) < config->drop_tslock_prob_on_low_snr)
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				state->status = 0;
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		} else {
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			/* recover if the signal improves */
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			if (prandom_u32_max(100) <
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			    config->recover_tslock_prob_on_good_snr)
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				state->status = FE_HAS_SIGNAL  |
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						FE_HAS_CARRIER |
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						FE_HAS_VITERBI |
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						FE_HAS_SYNC    |
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						FE_HAS_LOCK;
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		}
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	}
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	vidtv_demod_update_stats(&state->frontend);
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	*status = state->status;
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	return 0;
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}
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static int vidtv_demod_read_signal_strength(struct dvb_frontend *fe,
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					    u16 *strength)
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{
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	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
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	*strength = c->strength.stat[0].uvalue;
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	return 0;
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}
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/*
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 * NOTE:
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 * This is implemented here just to be used as an example for real
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 * demod drivers.
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 *
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 * Should only be implemented if it actually reads something from the hardware.
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 * Also, it should check for the locks, in order to avoid report wrong data
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 * to userspace.
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 */
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static int vidtv_demod_get_frontend(struct dvb_frontend *fe,
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				    struct dtv_frontend_properties *p)
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{
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	return 0;
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}
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static int vidtv_demod_set_frontend(struct dvb_frontend *fe)
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{
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	struct vidtv_demod_state *state = fe->demodulator_priv;
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	u32 tuner_status = 0;
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	int ret;
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	if (!fe->ops.tuner_ops.set_params)
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		return 0;
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	fe->ops.tuner_ops.set_params(fe);
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	/* store the CNR returned by the tuner */
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	ret = fe->ops.tuner_ops.get_rf_strength(fe, &state->tuner_cnr);
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	if (ret < 0)
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		return ret;
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	fe->ops.tuner_ops.get_status(fe, &tuner_status);
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	state->status = (state->tuner_cnr > 0) ?  FE_HAS_SIGNAL  |
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						    FE_HAS_CARRIER |
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						    FE_HAS_VITERBI |
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						    FE_HAS_SYNC    |
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						    FE_HAS_LOCK	 :
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						    0;
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	vidtv_demod_update_stats(fe);
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	if (fe->ops.i2c_gate_ctrl)
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		fe->ops.i2c_gate_ctrl(fe, 0);
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	return 0;
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}
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/*
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 * NOTE:
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 * This is implemented here just to be used as an example for real
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 * demod drivers.
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 *
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 * Should only be implemented if the demod has support for DVB-S or DVB-S2
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 */
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static int vidtv_demod_set_tone(struct dvb_frontend *fe,
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				enum fe_sec_tone_mode tone)
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{
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	return 0;
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}
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/*
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 * NOTE:
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 * This is implemented here just to be used as an example for real
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 * demod drivers.
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 *
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 * Should only be implemented if the demod has support for DVB-S or DVB-S2
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 */
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static int vidtv_demod_set_voltage(struct dvb_frontend *fe,
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				   enum fe_sec_voltage voltage)
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{
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	return 0;
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}
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/*
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 * NOTE:
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 * This is implemented here just to be used as an example for real
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 * demod drivers.
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 *
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 * Should only be implemented if the demod has support for DVB-S or DVB-S2
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 */
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static int vidtv_send_diseqc_msg(struct dvb_frontend *fe,
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				 struct dvb_diseqc_master_cmd *cmd)
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{
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	return 0;
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}
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/*
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 * NOTE:
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 * This is implemented here just to be used as an example for real
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 * demod drivers.
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 *
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 * Should only be implemented if the demod has support for DVB-S or DVB-S2
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 */
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static int vidtv_diseqc_send_burst(struct dvb_frontend *fe,
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				   enum fe_sec_mini_cmd burst)
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{
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	return 0;
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}
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static void vidtv_demod_release(struct dvb_frontend *fe)
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{
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	struct vidtv_demod_state *state = fe->demodulator_priv;
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	kfree(state);
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}
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static const struct dvb_frontend_ops vidtv_demod_ops = {
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	.delsys = {
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		SYS_DVBT,
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		SYS_DVBT2,
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		SYS_DVBC_ANNEX_A,
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		SYS_DVBS,
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		SYS_DVBS2,
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	},
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	.info = {
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		.name                   = "Dummy demod for DVB-T/T2/C/S/S2",
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		.frequency_min_hz       = 51 * MHz,
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		.frequency_max_hz       = 2150 * MHz,
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		.frequency_stepsize_hz  = 62500,
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		.frequency_tolerance_hz = 29500 * kHz,
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		.symbol_rate_min        = 1000000,
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		.symbol_rate_max        = 45000000,
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		.caps = FE_CAN_FEC_1_2 |
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			FE_CAN_FEC_2_3 |
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			FE_CAN_FEC_3_4 |
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			FE_CAN_FEC_4_5 |
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			FE_CAN_FEC_5_6 |
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			FE_CAN_FEC_6_7 |
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			FE_CAN_FEC_7_8 |
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			FE_CAN_FEC_8_9 |
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			FE_CAN_QAM_16 |
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			FE_CAN_QAM_64 |
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			FE_CAN_QAM_32 |
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			FE_CAN_QAM_128 |
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			FE_CAN_QAM_256 |
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			FE_CAN_QAM_AUTO |
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			FE_CAN_QPSK |
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			FE_CAN_FEC_AUTO |
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			FE_CAN_INVERSION_AUTO |
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			FE_CAN_TRANSMISSION_MODE_AUTO |
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			FE_CAN_GUARD_INTERVAL_AUTO |
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			FE_CAN_HIERARCHY_AUTO,
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	},
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	.release = vidtv_demod_release,
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						|
	.set_frontend = vidtv_demod_set_frontend,
 | 
						|
	.get_frontend = vidtv_demod_get_frontend,
 | 
						|
 | 
						|
	.read_status          = vidtv_demod_read_status,
 | 
						|
	.read_signal_strength = vidtv_demod_read_signal_strength,
 | 
						|
 | 
						|
	/* For DVB-S/S2 */
 | 
						|
	.set_voltage		= vidtv_demod_set_voltage,
 | 
						|
	.set_tone		= vidtv_demod_set_tone,
 | 
						|
	.diseqc_send_master_cmd	= vidtv_send_diseqc_msg,
 | 
						|
	.diseqc_send_burst	= vidtv_diseqc_send_burst,
 | 
						|
 | 
						|
};
 | 
						|
 | 
						|
static const struct i2c_device_id vidtv_demod_i2c_id_table[] = {
 | 
						|
	{"dvb_vidtv_demod", 0},
 | 
						|
	{}
 | 
						|
};
 | 
						|
MODULE_DEVICE_TABLE(i2c, vidtv_demod_i2c_id_table);
 | 
						|
 | 
						|
static int vidtv_demod_i2c_probe(struct i2c_client *client,
 | 
						|
				 const struct i2c_device_id *id)
 | 
						|
{
 | 
						|
	struct vidtv_tuner_config *config = client->dev.platform_data;
 | 
						|
	struct vidtv_demod_state *state;
 | 
						|
 | 
						|
	/* allocate memory for the internal state */
 | 
						|
	state = kzalloc(sizeof(*state), GFP_KERNEL);
 | 
						|
	if (!state)
 | 
						|
		return -ENOMEM;
 | 
						|
 | 
						|
	/* create dvb_frontend */
 | 
						|
	memcpy(&state->frontend.ops,
 | 
						|
	       &vidtv_demod_ops,
 | 
						|
	       sizeof(struct dvb_frontend_ops));
 | 
						|
 | 
						|
	memcpy(&state->config, config, sizeof(state->config));
 | 
						|
 | 
						|
	state->frontend.demodulator_priv = state;
 | 
						|
	i2c_set_clientdata(client, state);
 | 
						|
 | 
						|
	vidtv_clean_stats(&state->frontend);
 | 
						|
 | 
						|
	return 0;
 | 
						|
}
 | 
						|
 | 
						|
static void vidtv_demod_i2c_remove(struct i2c_client *client)
 | 
						|
{
 | 
						|
	struct vidtv_demod_state *state = i2c_get_clientdata(client);
 | 
						|
 | 
						|
	kfree(state);
 | 
						|
}
 | 
						|
 | 
						|
static struct i2c_driver vidtv_demod_i2c_driver = {
 | 
						|
	.driver = {
 | 
						|
		.name                = "dvb_vidtv_demod",
 | 
						|
		.suppress_bind_attrs = true,
 | 
						|
	},
 | 
						|
	.probe    = vidtv_demod_i2c_probe,
 | 
						|
	.remove   = vidtv_demod_i2c_remove,
 | 
						|
	.id_table = vidtv_demod_i2c_id_table,
 | 
						|
};
 | 
						|
 | 
						|
module_i2c_driver(vidtv_demod_i2c_driver);
 | 
						|
 | 
						|
MODULE_DESCRIPTION("Virtual DVB Demodulator Driver");
 | 
						|
MODULE_AUTHOR("Daniel W. S. Almeida");
 | 
						|
MODULE_LICENSE("GPL");
 |