diff options
Diffstat (limited to 'drivers/media/test-drivers/vidtv/vidtv_demod.c')
-rw-r--r-- | drivers/media/test-drivers/vidtv/vidtv_demod.c | 462 |
1 files changed, 462 insertions, 0 deletions
diff --git a/drivers/media/test-drivers/vidtv/vidtv_demod.c b/drivers/media/test-drivers/vidtv/vidtv_demod.c new file mode 100644 index 000000000..e7959ab1a --- /dev/null +++ b/drivers/media/test-drivers/vidtv/vidtv_demod.c @@ -0,0 +1,462 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * The Virtual DVB 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> + */ + +#include <linux/errno.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/printk.h> +#include <linux/random.h> +#include <linux/ratelimit.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/workqueue.h> + +#include <media/dvb_frontend.h> + +#include "vidtv_demod.h" + +#define POLL_THRD_TIME 2000 /* ms */ + +static const struct vidtv_demod_cnr_to_qual_s vidtv_demod_c_cnr_2_qual[] = { + /* from libdvbv5 source code, in milli db */ + { QAM_256, FEC_NONE, 34000, 38000}, + { QAM_64, FEC_NONE, 30000, 34000}, +}; + +static const struct vidtv_demod_cnr_to_qual_s vidtv_demod_s_cnr_2_qual[] = { + /* from libdvbv5 source code, in milli db */ + { QPSK, FEC_1_2, 7000, 10000}, + { QPSK, FEC_2_3, 9000, 12000}, + { QPSK, FEC_3_4, 10000, 13000}, + { QPSK, FEC_5_6, 11000, 14000}, + { QPSK, FEC_7_8, 12000, 15000}, +}; + +static const struct vidtv_demod_cnr_to_qual_s vidtv_demod_s2_cnr_2_qual[] = { + /* from libdvbv5 source code, in milli db */ + { QPSK, FEC_1_2, 9000, 12000}, + { QPSK, FEC_2_3, 11000, 14000}, + { QPSK, FEC_3_4, 12000, 15000}, + { QPSK, FEC_5_6, 12000, 15000}, + { QPSK, FEC_8_9, 13000, 16000}, + { QPSK, FEC_9_10, 13500, 16500}, + { PSK_8, FEC_2_3, 14500, 17500}, + { PSK_8, FEC_3_4, 16000, 19000}, + { PSK_8, FEC_5_6, 17500, 20500}, + { PSK_8, FEC_8_9, 19000, 22000}, +}; + +static const struct vidtv_demod_cnr_to_qual_s vidtv_demod_t_cnr_2_qual[] = { + /* from libdvbv5 source code, in milli db*/ + { QPSK, FEC_1_2, 4100, 5900}, + { QPSK, FEC_2_3, 6100, 9600}, + { QPSK, FEC_3_4, 7200, 12400}, + { QPSK, FEC_5_6, 8500, 15600}, + { QPSK, FEC_7_8, 9200, 17500}, + { QAM_16, FEC_1_2, 9800, 11800}, + { QAM_16, FEC_2_3, 12100, 15300}, + { QAM_16, FEC_3_4, 13400, 18100}, + { QAM_16, FEC_5_6, 14800, 21300}, + { QAM_16, FEC_7_8, 15700, 23600}, + { QAM_64, FEC_1_2, 14000, 16000}, + { QAM_64, FEC_2_3, 19900, 25400}, + { QAM_64, FEC_3_4, 24900, 27900}, + { QAM_64, FEC_5_6, 21300, 23300}, + { QAM_64, FEC_7_8, 22000, 24000}, +}; + +static const struct vidtv_demod_cnr_to_qual_s *vidtv_match_cnr_s(struct dvb_frontend *fe) +{ + const struct vidtv_demod_cnr_to_qual_s *cnr2qual = NULL; + struct device *dev = fe->dvb->device; + struct dtv_frontend_properties *c; + u32 array_size = 0; + u32 i; + + c = &fe->dtv_property_cache; + + switch (c->delivery_system) { + case SYS_DVBT: + case SYS_DVBT2: + cnr2qual = vidtv_demod_t_cnr_2_qual; + array_size = ARRAY_SIZE(vidtv_demod_t_cnr_2_qual); + break; + + case SYS_DVBS: + cnr2qual = vidtv_demod_s_cnr_2_qual; + array_size = ARRAY_SIZE(vidtv_demod_s_cnr_2_qual); + break; + + case SYS_DVBS2: + cnr2qual = vidtv_demod_s2_cnr_2_qual; + array_size = ARRAY_SIZE(vidtv_demod_s2_cnr_2_qual); + break; + + case SYS_DVBC_ANNEX_A: + cnr2qual = vidtv_demod_c_cnr_2_qual; + array_size = ARRAY_SIZE(vidtv_demod_c_cnr_2_qual); + break; + + default: + dev_warn_ratelimited(dev, + "%s: unsupported delivery system: %u\n", + __func__, + c->delivery_system); + break; + } + + for (i = 0; i < array_size; i++) + if (cnr2qual[i].modulation == c->modulation && + cnr2qual[i].fec == c->fec_inner) + return &cnr2qual[i]; + + return NULL; /* not found */ +} + +static void vidtv_clean_stats(struct dvb_frontend *fe) +{ + struct dtv_frontend_properties *c = &fe->dtv_property_cache; + + /* Fill the length of each status counter */ + + /* Signal is always available */ + c->strength.len = 1; + c->strength.stat[0].scale = FE_SCALE_DECIBEL; + c->strength.stat[0].svalue = 0; + + /* Usually available only after Viterbi lock */ + c->cnr.stat[0].scale = FE_SCALE_NOT_AVAILABLE; + c->cnr.stat[0].svalue = 0; + c->cnr.len = 1; + + /* Those depends on full lock */ + c->pre_bit_error.stat[0].scale = FE_SCALE_NOT_AVAILABLE; + c->pre_bit_error.stat[0].uvalue = 0; + c->pre_bit_error.len = 1; + c->pre_bit_count.stat[0].scale = FE_SCALE_NOT_AVAILABLE; + c->pre_bit_count.stat[0].uvalue = 0; + c->pre_bit_count.len = 1; + c->post_bit_error.stat[0].scale = FE_SCALE_NOT_AVAILABLE; + c->post_bit_error.stat[0].uvalue = 0; + c->post_bit_error.len = 1; + c->post_bit_count.stat[0].scale = FE_SCALE_NOT_AVAILABLE; + c->post_bit_count.stat[0].uvalue = 0; + c->post_bit_count.len = 1; + c->block_error.stat[0].scale = FE_SCALE_NOT_AVAILABLE; + c->block_error.stat[0].uvalue = 0; + c->block_error.len = 1; + c->block_count.stat[0].scale = FE_SCALE_NOT_AVAILABLE; + c->block_count.stat[0].uvalue = 0; + c->block_count.len = 1; +} + +static void vidtv_demod_update_stats(struct dvb_frontend *fe) +{ + struct dtv_frontend_properties *c = &fe->dtv_property_cache; + struct vidtv_demod_state *state = fe->demodulator_priv; + u32 scale; + + if (state->status & FE_HAS_LOCK) { + scale = FE_SCALE_COUNTER; + c->cnr.stat[0].scale = FE_SCALE_DECIBEL; + } else { + scale = FE_SCALE_NOT_AVAILABLE; + c->cnr.stat[0].scale = scale; + } + + c->pre_bit_error.stat[0].scale = scale; + c->pre_bit_count.stat[0].scale = scale; + c->post_bit_error.stat[0].scale = scale; + c->post_bit_count.stat[0].scale = scale; + c->block_error.stat[0].scale = scale; + c->block_count.stat[0].scale = scale; + + /* + * Add a 0.5% of randomness at the signal strength and CNR, + * and make them different, as we want to have something closer + * to a real case scenario. + * + * Also, usually, signal strength is a negative number in dBm. + */ + c->strength.stat[0].svalue = state->tuner_cnr; + c->strength.stat[0].svalue -= prandom_u32_max(state->tuner_cnr / 50); + c->strength.stat[0].svalue -= 68000; /* Adjust to a better range */ + + c->cnr.stat[0].svalue = state->tuner_cnr; + c->cnr.stat[0].svalue -= prandom_u32_max(state->tuner_cnr / 50); +} + +static int vidtv_demod_read_status(struct dvb_frontend *fe, + enum fe_status *status) +{ + struct vidtv_demod_state *state = fe->demodulator_priv; + const struct vidtv_demod_cnr_to_qual_s *cnr2qual = NULL; + struct vidtv_demod_config *config = &state->config; + u16 snr = 0; + + /* Simulate random lost of signal due to a bad-tuned channel */ + cnr2qual = vidtv_match_cnr_s(&state->frontend); + + if (cnr2qual && state->tuner_cnr < cnr2qual->cnr_good && + state->frontend.ops.tuner_ops.get_rf_strength) { + state->frontend.ops.tuner_ops.get_rf_strength(&state->frontend, + &snr); + + if (snr < cnr2qual->cnr_ok) { + /* eventually lose the TS lock */ + if (prandom_u32_max(100) < config->drop_tslock_prob_on_low_snr) + state->status = 0; + } else { + /* recover if the signal improves */ + if (prandom_u32_max(100) < + config->recover_tslock_prob_on_good_snr) + state->status = FE_HAS_SIGNAL | + FE_HAS_CARRIER | + FE_HAS_VITERBI | + FE_HAS_SYNC | + FE_HAS_LOCK; + } + } + + vidtv_demod_update_stats(&state->frontend); + + *status = state->status; + + return 0; +} + +static int vidtv_demod_read_signal_strength(struct dvb_frontend *fe, + u16 *strength) +{ + struct dtv_frontend_properties *c = &fe->dtv_property_cache; + + *strength = c->strength.stat[0].uvalue; + + return 0; +} + +/* + * NOTE: + * This is implemented here just to be used as an example for real + * demod drivers. + * + * Should only be implemented if it actually reads something from the hardware. + * Also, it should check for the locks, in order to avoid report wrong data + * to userspace. + */ +static int vidtv_demod_get_frontend(struct dvb_frontend *fe, + struct dtv_frontend_properties *p) +{ + return 0; +} + +static int vidtv_demod_set_frontend(struct dvb_frontend *fe) +{ + struct vidtv_demod_state *state = fe->demodulator_priv; + u32 tuner_status = 0; + int ret; + + if (!fe->ops.tuner_ops.set_params) + return 0; + + fe->ops.tuner_ops.set_params(fe); + + /* store the CNR returned by the tuner */ + ret = fe->ops.tuner_ops.get_rf_strength(fe, &state->tuner_cnr); + if (ret < 0) + return ret; + + fe->ops.tuner_ops.get_status(fe, &tuner_status); + state->status = (state->tuner_cnr > 0) ? FE_HAS_SIGNAL | + FE_HAS_CARRIER | + FE_HAS_VITERBI | + FE_HAS_SYNC | + FE_HAS_LOCK : + 0; + + vidtv_demod_update_stats(fe); + + if (fe->ops.i2c_gate_ctrl) + fe->ops.i2c_gate_ctrl(fe, 0); + + return 0; +} + +/* + * NOTE: + * This is implemented here just to be used as an example for real + * demod drivers. + * + * Should only be implemented if the demod has support for DVB-S or DVB-S2 + */ +static int vidtv_demod_set_tone(struct dvb_frontend *fe, + enum fe_sec_tone_mode tone) +{ + return 0; +} + +/* + * NOTE: + * This is implemented here just to be used as an example for real + * demod drivers. + * + * Should only be implemented if the demod has support for DVB-S or DVB-S2 + */ +static int vidtv_demod_set_voltage(struct dvb_frontend *fe, + enum fe_sec_voltage voltage) +{ + return 0; +} + +/* + * NOTE: + * This is implemented here just to be used as an example for real + * demod drivers. + * + * Should only be implemented if the demod has support for DVB-S or DVB-S2 + */ +static int vidtv_send_diseqc_msg(struct dvb_frontend *fe, + struct dvb_diseqc_master_cmd *cmd) +{ + return 0; +} + +/* + * NOTE: + * This is implemented here just to be used as an example for real + * demod drivers. + * + * Should only be implemented if the demod has support for DVB-S or DVB-S2 + */ +static int vidtv_diseqc_send_burst(struct dvb_frontend *fe, + enum fe_sec_mini_cmd burst) +{ + return 0; +} + +static void vidtv_demod_release(struct dvb_frontend *fe) +{ + struct vidtv_demod_state *state = fe->demodulator_priv; + + kfree(state); +} + +static const struct dvb_frontend_ops vidtv_demod_ops = { + .delsys = { + SYS_DVBT, + SYS_DVBT2, + SYS_DVBC_ANNEX_A, + SYS_DVBS, + SYS_DVBS2, + }, + + .info = { + .name = "Dummy demod for DVB-T/T2/C/S/S2", + .frequency_min_hz = 51 * MHz, + .frequency_max_hz = 2150 * MHz, + .frequency_stepsize_hz = 62500, + .frequency_tolerance_hz = 29500 * kHz, + .symbol_rate_min = 1000000, + .symbol_rate_max = 45000000, + + .caps = FE_CAN_FEC_1_2 | + FE_CAN_FEC_2_3 | + FE_CAN_FEC_3_4 | + FE_CAN_FEC_4_5 | + FE_CAN_FEC_5_6 | + FE_CAN_FEC_6_7 | + FE_CAN_FEC_7_8 | + FE_CAN_FEC_8_9 | + FE_CAN_QAM_16 | + FE_CAN_QAM_64 | + FE_CAN_QAM_32 | + FE_CAN_QAM_128 | + FE_CAN_QAM_256 | + FE_CAN_QAM_AUTO | + FE_CAN_QPSK | + FE_CAN_FEC_AUTO | + FE_CAN_INVERSION_AUTO | + FE_CAN_TRANSMISSION_MODE_AUTO | + FE_CAN_GUARD_INTERVAL_AUTO | + FE_CAN_HIERARCHY_AUTO, + }, + + .release = vidtv_demod_release, + + .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"); |