| Message ID | 20200520070334.1778751-4-dwlsalmeida@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | media: vidtv: implement a virtual DVB driver | expand |
On 5/20/20 1:03 AM, Daniel W. S. Almeida wrote: > From: "Daniel W. S. Almeida" <dwlsalmeida@gmail.com> > > Implement a I2C demodulator driver, simulating support for DVB-T, DVB-C > and DVB-S. > > This demodulator will periodically check the signal quality against a table > and drop the TS lock if it drops below a threshold value, regaining it in > the event that the signal improves. > > Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com> > --- > drivers/media/test-drivers/vidtv/Makefile | 3 +- > .../media/test-drivers/vidtv/vidtv_demod.c | 444 ++++++++++++++++++ > .../media/test-drivers/vidtv/vidtv_demod.h | 41 ++ > 3 files changed, 487 insertions(+), 1 deletion(-) > create mode 100644 drivers/media/test-drivers/vidtv/vidtv_demod.c > create mode 100644 drivers/media/test-drivers/vidtv/vidtv_demod.h > > diff --git a/drivers/media/test-drivers/vidtv/Makefile b/drivers/media/test-drivers/vidtv/Makefile > index 58e022c094e5e..21e50c11c94d0 100644 > --- a/drivers/media/test-drivers/vidtv/Makefile > +++ b/drivers/media/test-drivers/vidtv/Makefile > @@ -1,5 +1,6 @@ > # SPDX-License-Identifier: GPL-2.0 > > dvb-vidtv-tuner-objs := vidtv_tuner.o > +dvb-vidtv-demod-objs := vidtv_demod.o > > -obj-$(CONFIG_DVB_VIDTV) += dvb-vidtv-tuner.o > +obj-$(CONFIG_DVB_VIDTV) += dvb-vidtv-tuner.o dvb-vidtv-demod.o > 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 0000000000000..15912e063cf5a > --- /dev/null > +++ b/drivers/media/test-drivers/vidtv/vidtv_demod.c > @@ -0,0 +1,444 @@ > +// 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. > + * > + * Written by Daniel W. S. Almeida <dwlsalmeida@gmail.com> > + * 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" > + > +// FIXME: just added a random value here > +#define POLL_THRD_TIME 10 /* 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) Looks very odd: Move vidtv_match_cnr_s up and: static const struct vidtv_demod_cnr_to_qual_s vidtv_match_cnr_s(struct dvb_frontend *fe) is better. > +{ > + struct dtv_frontend_properties *c; > + const struct vidtv_demod_cnr_to_qual_s *cnr2qual = NULL; > + u32 array_size = 0; This looks really odd. Don't align them. Align them if it makes sense. It doesn't here. > + u32 i; > + > + c = &fe->dtv_property_cache; > + > + switch (c->delivery_system) { Indentation > + 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: > + pr_warn_ratelimited("%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_demod_poll_snr_handler(struct work_struct *work) > +{ > + /* > + * periodically check the signal quality and eventually > + * lose the TS lock if it dips too low > + */ > + struct vidtv_demod_state *state; > + const struct vidtv_demod_cnr_to_qual_s *cnr2qual = NULL; > + struct vidtv_demod_config *config; > + u16 snr = 0; > + > + state = container_of(work, struct vidtv_demod_state, poll_snr.work); > + config = &state->config; > + > + if (!state->frontend.ops.tuner_ops.get_rf_strength) > + return; > + > + state->frontend.ops.tuner_ops.get_rf_strength(&state->frontend, &snr); > + > + cnr2qual = vidtv_match_cnr_s(&state->frontend); > + if (!cnr2qual) > + return; > + > + 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; > + } > + > + schedule_delayed_work(&state->poll_snr, > + msecs_to_jiffies(POLL_THRD_TIME)); > +} > + > +static int vidtv_demod_read_status(struct dvb_frontend *fe, > + enum fe_status *status) > +{ > + struct vidtv_demod_state *state = fe->demodulator_priv; > + > + *status = state->status; > + > + return 0; > +} > + > +static int vidtv_demod_read_ber(struct dvb_frontend *fe, u32 *ber) > +{ > + *ber = 0; > + return 0; > +} > + > +static int vidtv_demod_read_signal_strength(struct dvb_frontend *fe, > + u16 *strength) > +{ > + *strength = 0; > + return 0; > +} > + > +static int vidtv_demod_read_snr(struct dvb_frontend *fe, u16 *snr) > +{ > + *snr = 0; > + return 0; > +} > + > +static int vidtv_demod_read_ucblocks(struct dvb_frontend *fe, u32 *ucblocks) > +{ > + *ucblocks = 0; > + 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; > + const struct vidtv_demod_cnr_to_qual_s *cnr2qual = NULL; > + u32 tuner_status = 0; > + > + if (fe->ops.tuner_ops.set_params) { > + fe->ops.tuner_ops.set_params(fe); > + > + /* store the CNR returned by the tuner */ > + fe->ops.tuner_ops.get_rf_strength(fe, &state->tuner_cnr); > + > + 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; > + cnr2qual = vidtv_match_cnr_s(fe); > + > + /* signal isn't good: might lose the lock eventually */ > + if (tuner_status == TUNER_STATUS_LOCKED && > + state->tuner_cnr < cnr2qual->cnr_good) { > + schedule_delayed_work(&state->poll_snr, > + msecs_to_jiffies(POLL_THRD_TIME)); > + > + state->poll_snr_thread_running = true; > + } > + > + if (fe->ops.i2c_gate_ctrl) > + fe->ops.i2c_gate_ctrl(fe, 0); > + } > + > + return 0; > +} > + > +static int vidtv_demod_sleep(struct dvb_frontend *fe) > +{ > + struct vidtv_demod_state *state = fe->demodulator_priv; > + > + if (state->poll_snr_thread_running) { > + cancel_delayed_work_sync(&state->poll_snr); > + state->poll_snr_thread_running = false; > + state->poll_snr_thread_restart = true; > + } > + return 0; > +} > + > +static int vidtv_demod_init(struct dvb_frontend *fe) > +{ > + struct vidtv_demod_state *state = fe->demodulator_priv; > + u32 tuner_status = 0; > + > + if (state->cold_start) > + INIT_DELAYED_WORK(&state->poll_snr, > + &vidtv_demod_poll_snr_handler); > + > + /* > + * At resume, start the snr poll thread only if it was suspended with > + * the thread running. Extra care should be taken here, as some tuner > + * status change might happen at resume time (for example, due to an > + * ioctl syscall to set_frontend, or due to a release syscall). > + */ > + fe->ops.tuner_ops.get_status(fe, &tuner_status); > + > + if (tuner_status == TUNER_STATUS_LOCKED && > + state->poll_snr_thread_restart) { > + schedule_delayed_work(&state->poll_snr, > + msecs_to_jiffies(POLL_THRD_TIME)); > + > + state->poll_snr_thread_restart = false; > + } > + > + state->cold_start = false; > + 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; > +} > + > +static void vidtv_demod_release(struct dvb_frontend *fe) > +{ > + struct vidtv_demod_state *state = fe->demodulator_priv; > + > + if (state->poll_snr_thread_running) > + cancel_delayed_work_sync(&state->poll_snr); > + > + 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_FEC_AUTO | Here is the first one. > + 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 | Duplicate entry? Cut and paste error perhaps. > + FE_CAN_INVERSION_AUTO | > + FE_CAN_TRANSMISSION_MODE_AUTO | > + FE_CAN_GUARD_INTERVAL_AUTO | > + FE_CAN_HIERARCHY_AUTO, > + }, > + > + .release = vidtv_demod_release, > + > + .init = vidtv_demod_init, > + .sleep = vidtv_demod_sleep, > + > + .set_frontend = vidtv_demod_set_frontend, > + .get_frontend = vidtv_demod_get_frontend, > + > + .read_status = vidtv_demod_read_status, > + .read_ber = vidtv_demod_read_ber, > + .read_signal_strength = vidtv_demod_read_signal_strength, > + .read_snr = vidtv_demod_read_snr, > + .read_ucblocks = vidtv_demod_read_ucblocks, > + > + /* For DVB-S/S2 */ > + .set_voltage = vidtv_demod_set_voltage, > + .set_tone = vidtv_demod_set_tone, > +}; > + > +static const struct i2c_device_id vidtv_demod_i2c_id_table[] = { > + {"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_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)); > + > + state->frontend.demodulator_priv = state; > + i2c_set_clientdata(client, state); > + > + return 0; > +} > + > +static int vidtv_demod_i2c_remove(struct i2c_client *client) > +{ > + struct vidtv_demod_state *state = i2c_get_clientdata(client); > + > + memset(&state->frontend.ops, 0, sizeof(struct dvb_frontend_ops)); > + state->frontend.demodulator_priv = NULL; > + kfree(state); > + > + return 0; > +} > + > +static struct i2c_driver vidtv_demod_i2c_driver = { > + .driver = { > + .name = "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"); > diff --git a/drivers/media/test-drivers/vidtv/vidtv_demod.h b/drivers/media/test-drivers/vidtv/vidtv_demod.h > new file mode 100644 > index 0000000000000..b14957d9d4ea0 > --- /dev/null > +++ b/drivers/media/test-drivers/vidtv/vidtv_demod.h > @@ -0,0 +1,41 @@ > +/* 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. > + * > + * Written by Daniel W. S. Almeida <dwlsalmeida@gmail.com> Change it to Copyright. Same comment on all files in this series. > + * 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 { > + /* attempt to use the same values as libdvbv5 */ > + u32 modulation; > + u32 fec; > + u32 cnr_ok, cnr_good; Move cnr_good to a separate line. Describe these variables. Whatare they for and what they do. > +}; > + > +struct vidtv_demod_config { > + /* probability of losing the lock due to low snr */ > + u8 drop_tslock_prob_on_low_snr; > + /* probability of recovering when the signal improves */ > + u8 recover_tslock_prob_on_good_snr; > +}; > + > +struct vidtv_demod_state { > + struct dvb_frontend frontend; > + struct vidtv_demod_config config; > + struct delayed_work poll_snr; > + enum fe_status status; > + u16 tuner_cnr; > + bool cold_start; > + bool poll_snr_thread_running; > + bool poll_snr_thread_restart; > +}; > +#endif // VIDTV_DEMOD_H > thanks, -- Shuah
diff --git a/drivers/media/test-drivers/vidtv/Makefile b/drivers/media/test-drivers/vidtv/Makefile index 58e022c094e5e..21e50c11c94d0 100644 --- a/drivers/media/test-drivers/vidtv/Makefile +++ b/drivers/media/test-drivers/vidtv/Makefile @@ -1,5 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 dvb-vidtv-tuner-objs := vidtv_tuner.o +dvb-vidtv-demod-objs := vidtv_demod.o -obj-$(CONFIG_DVB_VIDTV) += dvb-vidtv-tuner.o +obj-$(CONFIG_DVB_VIDTV) += dvb-vidtv-tuner.o dvb-vidtv-demod.o 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 0000000000000..15912e063cf5a --- /dev/null +++ b/drivers/media/test-drivers/vidtv/vidtv_demod.c @@ -0,0 +1,444 @@ +// 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. + * + * Written by Daniel W. S. Almeida <dwlsalmeida@gmail.com> + * 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" + +// FIXME: just added a random value here +#define POLL_THRD_TIME 10 /* 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) +{ + struct dtv_frontend_properties *c; + const struct vidtv_demod_cnr_to_qual_s *cnr2qual = NULL; + 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: + pr_warn_ratelimited("%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_demod_poll_snr_handler(struct work_struct *work) +{ + /* + * periodically check the signal quality and eventually + * lose the TS lock if it dips too low + */ + struct vidtv_demod_state *state; + const struct vidtv_demod_cnr_to_qual_s *cnr2qual = NULL; + struct vidtv_demod_config *config; + u16 snr = 0; + + state = container_of(work, struct vidtv_demod_state, poll_snr.work); + config = &state->config; + + if (!state->frontend.ops.tuner_ops.get_rf_strength) + return; + + state->frontend.ops.tuner_ops.get_rf_strength(&state->frontend, &snr); + + cnr2qual = vidtv_match_cnr_s(&state->frontend); + if (!cnr2qual) + return; + + 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; + } + + schedule_delayed_work(&state->poll_snr, + msecs_to_jiffies(POLL_THRD_TIME)); +} + +static int vidtv_demod_read_status(struct dvb_frontend *fe, + enum fe_status *status) +{ + struct vidtv_demod_state *state = fe->demodulator_priv; + + *status = state->status; + + return 0; +} + +static int vidtv_demod_read_ber(struct dvb_frontend *fe, u32 *ber) +{ + *ber = 0; + return 0; +} + +static int vidtv_demod_read_signal_strength(struct dvb_frontend *fe, + u16 *strength) +{ + *strength = 0; + return 0; +} + +static int vidtv_demod_read_snr(struct dvb_frontend *fe, u16 *snr) +{ + *snr = 0; + return 0; +} + +static int vidtv_demod_read_ucblocks(struct dvb_frontend *fe, u32 *ucblocks) +{ + *ucblocks = 0; + 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; + const struct vidtv_demod_cnr_to_qual_s *cnr2qual = NULL; + u32 tuner_status = 0; + + if (fe->ops.tuner_ops.set_params) { + fe->ops.tuner_ops.set_params(fe); + + /* store the CNR returned by the tuner */ + fe->ops.tuner_ops.get_rf_strength(fe, &state->tuner_cnr); + + 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; + cnr2qual = vidtv_match_cnr_s(fe); + + /* signal isn't good: might lose the lock eventually */ + if (tuner_status == TUNER_STATUS_LOCKED && + state->tuner_cnr < cnr2qual->cnr_good) { + schedule_delayed_work(&state->poll_snr, + msecs_to_jiffies(POLL_THRD_TIME)); + + state->poll_snr_thread_running = true; + } + + if (fe->ops.i2c_gate_ctrl) + fe->ops.i2c_gate_ctrl(fe, 0); + } + + return 0; +} + +static int vidtv_demod_sleep(struct dvb_frontend *fe) +{ + struct vidtv_demod_state *state = fe->demodulator_priv; + + if (state->poll_snr_thread_running) { + cancel_delayed_work_sync(&state->poll_snr); + state->poll_snr_thread_running = false; + state->poll_snr_thread_restart = true; + } + return 0; +} + +static int vidtv_demod_init(struct dvb_frontend *fe) +{ + struct vidtv_demod_state *state = fe->demodulator_priv; + u32 tuner_status = 0; + + if (state->cold_start) + INIT_DELAYED_WORK(&state->poll_snr, + &vidtv_demod_poll_snr_handler); + + /* + * At resume, start the snr poll thread only if it was suspended with + * the thread running. Extra care should be taken here, as some tuner + * status change might happen at resume time (for example, due to an + * ioctl syscall to set_frontend, or due to a release syscall). + */ + fe->ops.tuner_ops.get_status(fe, &tuner_status); + + if (tuner_status == TUNER_STATUS_LOCKED && + state->poll_snr_thread_restart) { + schedule_delayed_work(&state->poll_snr, + msecs_to_jiffies(POLL_THRD_TIME)); + + state->poll_snr_thread_restart = false; + } + + state->cold_start = false; + 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; +} + +static void vidtv_demod_release(struct dvb_frontend *fe) +{ + struct vidtv_demod_state *state = fe->demodulator_priv; + + if (state->poll_snr_thread_running) + cancel_delayed_work_sync(&state->poll_snr); + + 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_FEC_AUTO | + 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, + + .init = vidtv_demod_init, + .sleep = vidtv_demod_sleep, + + .set_frontend = vidtv_demod_set_frontend, + .get_frontend = vidtv_demod_get_frontend, + + .read_status = vidtv_demod_read_status, + .read_ber = vidtv_demod_read_ber, + .read_signal_strength = vidtv_demod_read_signal_strength, + .read_snr = vidtv_demod_read_snr, + .read_ucblocks = vidtv_demod_read_ucblocks, + + /* For DVB-S/S2 */ + .set_voltage = vidtv_demod_set_voltage, + .set_tone = vidtv_demod_set_tone, +}; + +static const struct i2c_device_id vidtv_demod_i2c_id_table[] = { + {"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_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)); + + state->frontend.demodulator_priv = state; + i2c_set_clientdata(client, state); + + return 0; +} + +static int vidtv_demod_i2c_remove(struct i2c_client *client) +{ + struct vidtv_demod_state *state = i2c_get_clientdata(client); + + memset(&state->frontend.ops, 0, sizeof(struct dvb_frontend_ops)); + state->frontend.demodulator_priv = NULL; + kfree(state); + + return 0; +} + +static struct i2c_driver vidtv_demod_i2c_driver = { + .driver = { + .name = "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"); diff --git a/drivers/media/test-drivers/vidtv/vidtv_demod.h b/drivers/media/test-drivers/vidtv/vidtv_demod.h new file mode 100644 index 0000000000000..b14957d9d4ea0 --- /dev/null +++ b/drivers/media/test-drivers/vidtv/vidtv_demod.h @@ -0,0 +1,41 @@ +/* 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. + * + * Written by Daniel W. S. Almeida <dwlsalmeida@gmail.com> + * 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 { + /* attempt to use the same values as libdvbv5 */ + u32 modulation; + u32 fec; + u32 cnr_ok, cnr_good; +}; + +struct vidtv_demod_config { + /* probability of losing the lock due to low snr */ + u8 drop_tslock_prob_on_low_snr; + /* probability of recovering when the signal improves */ + u8 recover_tslock_prob_on_good_snr; +}; + +struct vidtv_demod_state { + struct dvb_frontend frontend; + struct vidtv_demod_config config; + struct delayed_work poll_snr; + enum fe_status status; + u16 tuner_cnr; + bool cold_start; + bool poll_snr_thread_running; + bool poll_snr_thread_restart; +}; +#endif // VIDTV_DEMOD_H