462 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * The Virtual DVB test driver serves as a reference DVB driver and helps4 * validate the existing APIs in the media subsystem. It can also aid5 * developers working on userspace applications.6 *7 * Copyright (C) 2020 Daniel W. S. Almeida8 * Based on the example driver written by Emard <emard@softhome.net>9 */10 11#include <linux/errno.h>12#include <linux/i2c.h>13#include <linux/init.h>14#include <linux/kernel.h>15#include <linux/module.h>16#include <linux/printk.h>17#include <linux/random.h>18#include <linux/ratelimit.h>19#include <linux/slab.h>20#include <linux/string.h>21#include <linux/workqueue.h>22 23#include <media/dvb_frontend.h>24 25#include "vidtv_demod.h"26 27#define POLL_THRD_TIME 2000 /* ms */28 29static const struct vidtv_demod_cnr_to_qual_s vidtv_demod_c_cnr_2_qual[] = {30 /* from libdvbv5 source code, in milli db */31 { QAM_256, FEC_NONE, 34000, 38000},32 { QAM_64, FEC_NONE, 30000, 34000},33};34 35static const struct vidtv_demod_cnr_to_qual_s vidtv_demod_s_cnr_2_qual[] = {36 /* from libdvbv5 source code, in milli db */37 { QPSK, FEC_1_2, 7000, 10000},38 { QPSK, FEC_2_3, 9000, 12000},39 { QPSK, FEC_3_4, 10000, 13000},40 { QPSK, FEC_5_6, 11000, 14000},41 { QPSK, FEC_7_8, 12000, 15000},42};43 44static const struct vidtv_demod_cnr_to_qual_s vidtv_demod_s2_cnr_2_qual[] = {45 /* from libdvbv5 source code, in milli db */46 { QPSK, FEC_1_2, 9000, 12000},47 { QPSK, FEC_2_3, 11000, 14000},48 { QPSK, FEC_3_4, 12000, 15000},49 { QPSK, FEC_5_6, 12000, 15000},50 { QPSK, FEC_8_9, 13000, 16000},51 { QPSK, FEC_9_10, 13500, 16500},52 { PSK_8, FEC_2_3, 14500, 17500},53 { PSK_8, FEC_3_4, 16000, 19000},54 { PSK_8, FEC_5_6, 17500, 20500},55 { PSK_8, FEC_8_9, 19000, 22000},56};57 58static const struct vidtv_demod_cnr_to_qual_s vidtv_demod_t_cnr_2_qual[] = {59 /* from libdvbv5 source code, in milli db*/60 { QPSK, FEC_1_2, 4100, 5900},61 { QPSK, FEC_2_3, 6100, 9600},62 { QPSK, FEC_3_4, 7200, 12400},63 { QPSK, FEC_5_6, 8500, 15600},64 { QPSK, FEC_7_8, 9200, 17500},65 { QAM_16, FEC_1_2, 9800, 11800},66 { QAM_16, FEC_2_3, 12100, 15300},67 { QAM_16, FEC_3_4, 13400, 18100},68 { QAM_16, FEC_5_6, 14800, 21300},69 { QAM_16, FEC_7_8, 15700, 23600},70 { QAM_64, FEC_1_2, 14000, 16000},71 { QAM_64, FEC_2_3, 19900, 25400},72 { QAM_64, FEC_3_4, 24900, 27900},73 { QAM_64, FEC_5_6, 21300, 23300},74 { QAM_64, FEC_7_8, 22000, 24000},75};76 77static const struct vidtv_demod_cnr_to_qual_s *vidtv_match_cnr_s(struct dvb_frontend *fe)78{79 const struct vidtv_demod_cnr_to_qual_s *cnr2qual = NULL;80 struct device *dev = fe->dvb->device;81 struct dtv_frontend_properties *c;82 u32 array_size = 0;83 u32 i;84 85 c = &fe->dtv_property_cache;86 87 switch (c->delivery_system) {88 case SYS_DVBT:89 case SYS_DVBT2:90 cnr2qual = vidtv_demod_t_cnr_2_qual;91 array_size = ARRAY_SIZE(vidtv_demod_t_cnr_2_qual);92 break;93 94 case SYS_DVBS:95 cnr2qual = vidtv_demod_s_cnr_2_qual;96 array_size = ARRAY_SIZE(vidtv_demod_s_cnr_2_qual);97 break;98 99 case SYS_DVBS2:100 cnr2qual = vidtv_demod_s2_cnr_2_qual;101 array_size = ARRAY_SIZE(vidtv_demod_s2_cnr_2_qual);102 break;103 104 case SYS_DVBC_ANNEX_A:105 cnr2qual = vidtv_demod_c_cnr_2_qual;106 array_size = ARRAY_SIZE(vidtv_demod_c_cnr_2_qual);107 break;108 109 default:110 dev_warn_ratelimited(dev,111 "%s: unsupported delivery system: %u\n",112 __func__,113 c->delivery_system);114 break;115 }116 117 for (i = 0; i < array_size; i++)118 if (cnr2qual[i].modulation == c->modulation &&119 cnr2qual[i].fec == c->fec_inner)120 return &cnr2qual[i];121 122 return NULL; /* not found */123}124 125static void vidtv_clean_stats(struct dvb_frontend *fe)126{127 struct dtv_frontend_properties *c = &fe->dtv_property_cache;128 129 /* Fill the length of each status counter */130 131 /* Signal is always available */132 c->strength.len = 1;133 c->strength.stat[0].scale = FE_SCALE_DECIBEL;134 c->strength.stat[0].svalue = 0;135 136 /* Usually available only after Viterbi lock */137 c->cnr.stat[0].scale = FE_SCALE_NOT_AVAILABLE;138 c->cnr.stat[0].svalue = 0;139 c->cnr.len = 1;140 141 /* Those depends on full lock */142 c->pre_bit_error.stat[0].scale = FE_SCALE_NOT_AVAILABLE;143 c->pre_bit_error.stat[0].uvalue = 0;144 c->pre_bit_error.len = 1;145 c->pre_bit_count.stat[0].scale = FE_SCALE_NOT_AVAILABLE;146 c->pre_bit_count.stat[0].uvalue = 0;147 c->pre_bit_count.len = 1;148 c->post_bit_error.stat[0].scale = FE_SCALE_NOT_AVAILABLE;149 c->post_bit_error.stat[0].uvalue = 0;150 c->post_bit_error.len = 1;151 c->post_bit_count.stat[0].scale = FE_SCALE_NOT_AVAILABLE;152 c->post_bit_count.stat[0].uvalue = 0;153 c->post_bit_count.len = 1;154 c->block_error.stat[0].scale = FE_SCALE_NOT_AVAILABLE;155 c->block_error.stat[0].uvalue = 0;156 c->block_error.len = 1;157 c->block_count.stat[0].scale = FE_SCALE_NOT_AVAILABLE;158 c->block_count.stat[0].uvalue = 0;159 c->block_count.len = 1;160}161 162static void vidtv_demod_update_stats(struct dvb_frontend *fe)163{164 struct dtv_frontend_properties *c = &fe->dtv_property_cache;165 struct vidtv_demod_state *state = fe->demodulator_priv;166 u32 scale;167 168 if (state->status & FE_HAS_LOCK) {169 scale = FE_SCALE_COUNTER;170 c->cnr.stat[0].scale = FE_SCALE_DECIBEL;171 } else {172 scale = FE_SCALE_NOT_AVAILABLE;173 c->cnr.stat[0].scale = scale;174 }175 176 c->pre_bit_error.stat[0].scale = scale;177 c->pre_bit_count.stat[0].scale = scale;178 c->post_bit_error.stat[0].scale = scale;179 c->post_bit_count.stat[0].scale = scale;180 c->block_error.stat[0].scale = scale;181 c->block_count.stat[0].scale = scale;182 183 /*184 * Add a 0.5% of randomness at the signal strength and CNR,185 * and make them different, as we want to have something closer186 * to a real case scenario.187 *188 * Also, usually, signal strength is a negative number in dBm.189 */190 c->strength.stat[0].svalue = state->tuner_cnr;191 c->strength.stat[0].svalue -= get_random_u32_below(state->tuner_cnr / 50);192 c->strength.stat[0].svalue -= 68000; /* Adjust to a better range */193 194 c->cnr.stat[0].svalue = state->tuner_cnr;195 c->cnr.stat[0].svalue -= get_random_u32_below(state->tuner_cnr / 50);196}197 198static int vidtv_demod_read_status(struct dvb_frontend *fe,199 enum fe_status *status)200{201 struct vidtv_demod_state *state = fe->demodulator_priv;202 const struct vidtv_demod_cnr_to_qual_s *cnr2qual = NULL;203 struct vidtv_demod_config *config = &state->config;204 u16 snr = 0;205 206 /* Simulate random lost of signal due to a bad-tuned channel */207 cnr2qual = vidtv_match_cnr_s(&state->frontend);208 209 if (cnr2qual && state->tuner_cnr < cnr2qual->cnr_good &&210 state->frontend.ops.tuner_ops.get_rf_strength) {211 state->frontend.ops.tuner_ops.get_rf_strength(&state->frontend,212 &snr);213 214 if (snr < cnr2qual->cnr_ok) {215 /* eventually lose the TS lock */216 if (get_random_u32_below(100) < config->drop_tslock_prob_on_low_snr)217 state->status = 0;218 } else {219 /* recover if the signal improves */220 if (get_random_u32_below(100) <221 config->recover_tslock_prob_on_good_snr)222 state->status = FE_HAS_SIGNAL |223 FE_HAS_CARRIER |224 FE_HAS_VITERBI |225 FE_HAS_SYNC |226 FE_HAS_LOCK;227 }228 }229 230 vidtv_demod_update_stats(&state->frontend);231 232 *status = state->status;233 234 return 0;235}236 237static int vidtv_demod_read_signal_strength(struct dvb_frontend *fe,238 u16 *strength)239{240 struct dtv_frontend_properties *c = &fe->dtv_property_cache;241 242 *strength = c->strength.stat[0].uvalue;243 244 return 0;245}246 247/*248 * NOTE:249 * This is implemented here just to be used as an example for real250 * demod drivers.251 *252 * Should only be implemented if it actually reads something from the hardware.253 * Also, it should check for the locks, in order to avoid report wrong data254 * to userspace.255 */256static int vidtv_demod_get_frontend(struct dvb_frontend *fe,257 struct dtv_frontend_properties *p)258{259 return 0;260}261 262static int vidtv_demod_set_frontend(struct dvb_frontend *fe)263{264 struct vidtv_demod_state *state = fe->demodulator_priv;265 u32 tuner_status = 0;266 int ret;267 268 if (!fe->ops.tuner_ops.set_params)269 return 0;270 271 fe->ops.tuner_ops.set_params(fe);272 273 /* store the CNR returned by the tuner */274 ret = fe->ops.tuner_ops.get_rf_strength(fe, &state->tuner_cnr);275 if (ret < 0)276 return ret;277 278 fe->ops.tuner_ops.get_status(fe, &tuner_status);279 state->status = (state->tuner_cnr > 0) ? FE_HAS_SIGNAL |280 FE_HAS_CARRIER |281 FE_HAS_VITERBI |282 FE_HAS_SYNC |283 FE_HAS_LOCK :284 0;285 286 vidtv_demod_update_stats(fe);287 288 if (fe->ops.i2c_gate_ctrl)289 fe->ops.i2c_gate_ctrl(fe, 0);290 291 return 0;292}293 294/*295 * NOTE:296 * This is implemented here just to be used as an example for real297 * demod drivers.298 *299 * Should only be implemented if the demod has support for DVB-S or DVB-S2300 */301static int vidtv_demod_set_tone(struct dvb_frontend *fe,302 enum fe_sec_tone_mode tone)303{304 return 0;305}306 307/*308 * NOTE:309 * This is implemented here just to be used as an example for real310 * demod drivers.311 *312 * Should only be implemented if the demod has support for DVB-S or DVB-S2313 */314static int vidtv_demod_set_voltage(struct dvb_frontend *fe,315 enum fe_sec_voltage voltage)316{317 return 0;318}319 320/*321 * NOTE:322 * This is implemented here just to be used as an example for real323 * demod drivers.324 *325 * Should only be implemented if the demod has support for DVB-S or DVB-S2326 */327static int vidtv_send_diseqc_msg(struct dvb_frontend *fe,328 struct dvb_diseqc_master_cmd *cmd)329{330 return 0;331}332 333/*334 * NOTE:335 * This is implemented here just to be used as an example for real336 * demod drivers.337 *338 * Should only be implemented if the demod has support for DVB-S or DVB-S2339 */340static int vidtv_diseqc_send_burst(struct dvb_frontend *fe,341 enum fe_sec_mini_cmd burst)342{343 return 0;344}345 346static void vidtv_demod_release(struct dvb_frontend *fe)347{348 struct vidtv_demod_state *state = fe->demodulator_priv;349 350 kfree(state);351}352 353static const struct dvb_frontend_ops vidtv_demod_ops = {354 .delsys = {355 SYS_DVBT,356 SYS_DVBT2,357 SYS_DVBC_ANNEX_A,358 SYS_DVBS,359 SYS_DVBS2,360 },361 362 .info = {363 .name = "Dummy demod for DVB-T/T2/C/S/S2",364 .frequency_min_hz = 51 * MHz,365 .frequency_max_hz = 2150 * MHz,366 .frequency_stepsize_hz = 62500,367 .frequency_tolerance_hz = 29500 * kHz,368 .symbol_rate_min = 1000000,369 .symbol_rate_max = 45000000,370 371 .caps = FE_CAN_FEC_1_2 |372 FE_CAN_FEC_2_3 |373 FE_CAN_FEC_3_4 |374 FE_CAN_FEC_4_5 |375 FE_CAN_FEC_5_6 |376 FE_CAN_FEC_6_7 |377 FE_CAN_FEC_7_8 |378 FE_CAN_FEC_8_9 |379 FE_CAN_QAM_16 |380 FE_CAN_QAM_64 |381 FE_CAN_QAM_32 |382 FE_CAN_QAM_128 |383 FE_CAN_QAM_256 |384 FE_CAN_QAM_AUTO |385 FE_CAN_QPSK |386 FE_CAN_FEC_AUTO |387 FE_CAN_INVERSION_AUTO |388 FE_CAN_TRANSMISSION_MODE_AUTO |389 FE_CAN_GUARD_INTERVAL_AUTO |390 FE_CAN_HIERARCHY_AUTO,391 },392 393 .release = vidtv_demod_release,394 395 .set_frontend = vidtv_demod_set_frontend,396 .get_frontend = vidtv_demod_get_frontend,397 398 .read_status = vidtv_demod_read_status,399 .read_signal_strength = vidtv_demod_read_signal_strength,400 401 /* For DVB-S/S2 */402 .set_voltage = vidtv_demod_set_voltage,403 .set_tone = vidtv_demod_set_tone,404 .diseqc_send_master_cmd = vidtv_send_diseqc_msg,405 .diseqc_send_burst = vidtv_diseqc_send_burst,406 407};408 409static const struct i2c_device_id vidtv_demod_i2c_id_table[] = {410 { "dvb_vidtv_demod" },411 {}412};413MODULE_DEVICE_TABLE(i2c, vidtv_demod_i2c_id_table);414 415static int vidtv_demod_i2c_probe(struct i2c_client *client)416{417 struct vidtv_tuner_config *config = client->dev.platform_data;418 struct vidtv_demod_state *state;419 420 /* allocate memory for the internal state */421 state = kzalloc(sizeof(*state), GFP_KERNEL);422 if (!state)423 return -ENOMEM;424 425 /* create dvb_frontend */426 memcpy(&state->frontend.ops,427 &vidtv_demod_ops,428 sizeof(struct dvb_frontend_ops));429 430 memcpy(&state->config, config, sizeof(state->config));431 432 state->frontend.demodulator_priv = state;433 i2c_set_clientdata(client, state);434 435 vidtv_clean_stats(&state->frontend);436 437 return 0;438}439 440static void vidtv_demod_i2c_remove(struct i2c_client *client)441{442 struct vidtv_demod_state *state = i2c_get_clientdata(client);443 444 kfree(state);445}446 447static struct i2c_driver vidtv_demod_i2c_driver = {448 .driver = {449 .name = "dvb_vidtv_demod",450 .suppress_bind_attrs = true,451 },452 .probe = vidtv_demod_i2c_probe,453 .remove = vidtv_demod_i2c_remove,454 .id_table = vidtv_demod_i2c_id_table,455};456 457module_i2c_driver(vidtv_demod_i2c_driver);458 459MODULE_DESCRIPTION("Virtual DVB Demodulator Driver");460MODULE_AUTHOR("Daniel W. S. Almeida");461MODULE_LICENSE("GPL");462