Em Wed, 18 Mar 2020 03:00:16 -0300
"Daniel W. S. Almeida" <dwlsalmeida@xxxxxxxxx> escreveu:
> From: "Daniel W. S. Almeida" <dwlsalmeida@xxxxxxxxx>
>
> 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.
>
> This dummy tuner should support common TV standards such as DVB-T/T2/S/S2,
> ISDB-T and ATSC when completed.
>
> Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@xxxxxxxxx>
> ---
> drivers/media/tuners/Kconfig | 9 +
> drivers/media/tuners/Makefile | 1 +
> drivers/media/tuners/dvb_dummy_tuner.c | 421 +++++++++++++++++++++++++
> 3 files changed, 431 insertions(+)
> create mode 100644 drivers/media/tuners/dvb_dummy_tuner.c
>
> diff --git a/drivers/media/tuners/Kconfig b/drivers/media/tuners/Kconfig
> index e104bb7766e1..8ad54339ceee 100644
> --- a/drivers/media/tuners/Kconfig
> +++ b/drivers/media/tuners/Kconfig
> @@ -296,4 +296,13 @@ config MEDIA_TUNER_QM1D1B0004
> default m if !MEDIA_SUBDRV_AUTOSELECT
> help
> Sharp QM1D1B0004 ISDB-S tuner driver.
> +
> +config MEDIA_TUNER_DVB_DUMMY_TUNER
> + tristate "Dummy DVB Media Tuner"
> + depends on MEDIA_SUPPORT && I2C
> + help
> + Dummy DVB media tuner driver
> + 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.
> endmenu
> diff --git a/drivers/media/tuners/Makefile b/drivers/media/tuners/Makefile
> index 7b4f8423501e..f98de1cf2e19 100644
> --- a/drivers/media/tuners/Makefile
> +++ b/drivers/media/tuners/Makefile
> @@ -44,5 +44,6 @@ obj-$(CONFIG_MEDIA_TUNER_QM1D1C0042) += qm1d1c0042.o
> obj-$(CONFIG_MEDIA_TUNER_QM1D1B0004) += qm1d1b0004.o
> obj-$(CONFIG_MEDIA_TUNER_M88RS6000T) += m88rs6000t.o
> obj-$(CONFIG_MEDIA_TUNER_TDA18250) += tda18250.o
> +obj-$(CONFIG_MEDIA_TUNER_DVB_DUMMY_TUNER) += dvb_dummy_tuner.o
>
> ccflags-y += -I$(srctree)/drivers/media/dvb-frontends
> diff --git a/drivers/media/tuners/dvb_dummy_tuner.c b/drivers/media/tuners/dvb_dummy_tuner.c
> new file mode 100644
> index 000000000000..1408a8c84be2
> --- /dev/null
> +++ b/drivers/media/tuners/dvb_dummy_tuner.c
> @@ -0,0 +1,421 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2020 Daniel W. S. Almeida <dwlsalmeida@xxxxxxxxx>
> + *
> + * 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.
> + *
> + * This dummy tuner should support common TV standards such as
> + * DVB-T/T2/S/S2, ISDB-T and ATSC when completed.
> + *
> + */
> +
> +#include <linux/errno.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/types.h>
> +#include <media/dvb_frontend.h>
> +
> +struct dvb_dummy_tuner_config {
> + struct dvb_frontend *fe;
> + u32 mock_power_up_delay_msec;
> + u32 mock_tune_delay_msec;
> + u32 mock_sleep_delay_msec;
> + u32 mock_resume_delay_msec;
> + u32 dummy_valid_dvb_t_frequencies[8];
> + u32 dummy_valid_dvb_c_frequencies[8];
> + u32 dummy_valid_dvb_s_frequencies[8];
> + u8 max_frequency_shift_hz;
> +};
> +
> +struct dvb_dummy_tuner_cnr_to_qual_s {
> + /* attempt to use the same values as libdvbv5 */
> + u32 modulation;
> + u32 fec;
> + u32 cnr_ok, cnr_good;
> +};
> +
> +struct dvb_dummy_tuner_cnr_to_qual_s dvb_c_cnr_2_qual[] = {
> + /* from libdvbv5 source code */
> + { QAM_256, FEC_NONE, 34., 38.},
> + { QAM_64, FEC_NONE, 30., 34.},
Instead of using float point, you should multiply those by some value,
like 1000. So, 34.0 dB would become 34000. Btw, that's the way the DVBv5
API expects it: as mili-dB. See FE_SCALE_DECIBEL at:
https://linuxtv.org/downloads/v4l-dvb-apis-new/uapi/dvb/frontend-stat-properties.html#dtv-stat-cnr
> +};
> +
> +struct dvb_dummy_tuner_cnr_to_qual_s dvb_s_cnr_2_qual[] = {
> + /* from libdvbv5 source code */
> + { QPSK, FEC_1_2, 7., 10.},
> +
> + { QPSK, FEC_2_3, 9., 12.},
> + { QPSK, FEC_3_4, 10., 13.},
> + { QPSK, FEC_5_6, 11., 14.},
> +
> + { QPSK, FEC_7_8, 12., 15.},
> +};
> +
> +struct dvb_dummy_tuner_cnr_to_qual_s dvb_s2_cnr_2_qual[] = {
> + /* from libdvbv5 source code */
> + { QPSK, FEC_1_2, 9., 12.},
> + { QPSK, FEC_2_3, 11., 14.},
> + { QPSK, FEC_3_4, 12., 15.},
> + { QPSK, FEC_5_6, 12., 15.},
> + { QPSK, FEC_8_9, 13., 16.},
> + { QPSK, FEC_9_10, 13.5, 16.5},
> + { PSK_8, FEC_2_3, 14.5, 17.5},
> + { PSK_8, FEC_3_4, 16., 19.},
> + { PSK_8, FEC_5_6, 17.5, 20.5},
> + { PSK_8, FEC_8_9, 19., 22.},
> +};
> +
> +static struct dvb_dummy_tuner_cnr_to_qual_s dvb_t_cnr_2_qual[] = {
> + /* from libdvbv5 source code */
> + { QPSK, FEC_1_2, 4.1, 5.9},
> + { QPSK, FEC_2_3, 6.1, 9.6},
> + { QPSK, FEC_3_4, 7.2, 12.4},
> + { QPSK, FEC_5_6, 8.5, 15.6},
> + { QPSK, FEC_7_8, 9.2, 17.5},
> +
> + { QAM_16, FEC_1_2, 9.8, 11.8},
> + { QAM_16, FEC_2_3, 12.1, 15.3},
> + { QAM_16, FEC_3_4, 13.4, 18.1},
> + { QAM_16, FEC_5_6, 14.8, 21.3},
> + { QAM_16, FEC_7_8, 15.7, 23.6},
> +
> + { QAM_64, FEC_1_2, 14.0, 16.0},
> + { QAM_64, FEC_2_3, 19.9, 25.4},
> + { QAM_64, FEC_3_4, 24.9, 27.9},
> + { QAM_64, FEC_5_6, 21.3, 23.3},
> + { QAM_64, FEC_7_8, 22.0, 24.0},
> +};
> +
> +enum dvb_dummy_tuner_lock_status {
> + STATUS_NO_LOCK = 0,
> + STATUS_LOCKED = TUNER_STATUS_LOCKED,
> +};
> +
> +enum dvb_dummy_tuner_power_status {
> + STATUS_UNKNOWN,
> + STATUS_ASLEEP,
> + STATUS_ACTIVE
> +};
> +
> +enum dvb_dummy_tuner_frequency_shift_status {
> + EXACT_MATCH,
> + CLOSE_MATCH,
> + TOO_FAR_OFF
> +};
> +
> +struct dvb_dummy_tuner_hardware_state {
> + enum dvb_dummy_tuner_power_status power_status;
> + enum dvb_dummy_tuner_lock_status lock_status;
> + u32 if_frequency;
> + u32 tuned_frequency;
> + u32 bandwidth;
> +};
> +
> +struct dvb_dummy_tuner_dev {
> + struct dvb_frontend *fe;
> + struct dvb_dummy_tuner_hardware_state hw_state;
> + struct dvb_dummy_tuner_config config;
> +};
> +
> +static struct dvb_dummy_tuner_dev*
> +dvb_dummy_tuner_get_dev(struct dvb_frontend *fe)
> +{
> + struct i2c_client *client = fe->tuner_priv;
> +
> + return (struct dvb_dummy_tuner_dev *)i2c_get_clientdata(client);
> +}
> +
> +static bool dvb_dummy_tuner_check_frequency_shift(struct dvb_frontend *fe)
> +{
> + struct dvb_dummy_tuner_dev *tuner_dev = dvb_dummy_tuner_get_dev(fe);
> + struct dtv_frontend_properties *c = &fe->dtv_property_cache;
> + struct dvb_dummy_tuner_config config = tuner_dev->config;
> + u32 *valid_frequencies = NULL;
> + u32 array_sz = 0;
> + u32 i;
> +
> + switch (c->delivery_system) {
> + case SYS_DVBT:
> + case SYS_DVBT2:
> + valid_frequencies =
> + config.dummy_valid_dvb_t_frequencies;
Please avoid splitting assignments like that on multiple lines.
Btw, I would just do a s/frequencies/freqs/. So, that would be:
valid_freqs = config.dummy_valid_dvb_t_freqs;
> + array_sz = ARRAY_SIZE(config.dummy_valid_dvb_t_frequencies);
> + break;
> + case SYS_DVBS:
> + case SYS_DVBS2:
> + valid_frequencies =
> + config.dummy_valid_dvb_s_frequencies;
> + array_sz = ARRAY_SIZE(config.dummy_valid_dvb_s_frequencies);
> + break;
> + case SYS_DVBC_ANNEX_A:
> + valid_frequencies =
> + config.dummy_valid_dvb_c_frequencies;
> + array_sz = ARRAY_SIZE(config.dummy_valid_dvb_c_frequencies);
> + break;
> +
> + default:
> + pr_warn("%s: unsupported delivery system: %u\n",
> + __func__,
> + c->delivery_system);
> + break;
> + }
> +
> + for (i = 0; i < array_sz; i++) {
> + if (c->frequency == valid_frequencies[i])
> + return EXACT_MATCH;
I would, instead, return 0 here.
> + else if (c->frequency >= ) -
> + config.max_frequency_shift_hz &&
> + c->frequency <= valid_frequencies[i] +
> + config.max_frequency_shift_hz)
> + return CLOSE_MATCH;
I would, instead, do:
return abs((c->frequency - valid_frequencies[i]) * 100 / config.max_frequency_shift_hz);
This will provide a value from 0 to 100 that would indicate how far is the
tuned frequency from the right one.
> + }
> +
> + return TOO_FAR_OFF;
I would return -1.
> +}
> +
> +static int
> +dvb_dummy_tuner_get_signal_strength(struct dvb_frontend *fe, u16 *strength)
> +{
> + struct dtv_frontend_properties *c = &fe->dtv_property_cache;
> + struct dvb_dummy_tuner_cnr_to_qual_s *cnr2qual = NULL;
> + u32 array_size = 0;
> + enum dvb_dummy_tuner_frequency_shift_status shift_status;
> + u32 i;
> +
> + shift_status = dvb_dummy_tuner_check_frequency_shift(fe);
> +
> + switch (c->delivery_system) {
> + case SYS_DVBT:
> + case SYS_DVBT2:
> + cnr2qual = dvb_t_cnr_2_qual;
> + array_size = ARRAY_SIZE(dvb_t_cnr_2_qual);
> + break;
> +
> + case SYS_DVBS:
> + cnr2qual = dvb_s_cnr_2_qual;
> + array_size = ARRAY_SIZE(dvb_s_cnr_2_qual);
> + break;
> +
> + case SYS_DVBS2:
> + cnr2qual = dvb_s2_cnr_2_qual;
> + array_size = ARRAY_SIZE(dvb_s2_cnr_2_qual);
> + break;
> +
> + case SYS_DVBC_ANNEX_A:
> + cnr2qual = dvb_c_cnr_2_qual;
> + array_size = ARRAY_SIZE(dvb_c_cnr_2_qual);
> + break;
> +
> + default:
> + pr_warn("%s: unsupported delivery system: %u\n",
> + __func__,
> + c->delivery_system);
> + return -EINVAL;
> + }
> +
> + for (i = 0; i <= array_size; i++) {
> + if (cnr2qual[i].modulation == c->modulation &&
> + cnr2qual[i].fec == c->fec_inner) {
> + *strength = (shift_status == EXACT_MATCH) ?
> + cnr2qual[i].cnr_good :
> + (shift_status == CLOSE_MATCH) ?
> + cnr2qual[i].cnr_ok :
> + cnr2qual[i].cnr_ok -
> + (cnr2qual[i].cnr_good - cnr2qual[i].cnr_ok);
> + return 0;
> + }
> +
> + }
> +
> + /* default to some random values if we can't match against the table */
> + *strength = (shift_status == EXACT_MATCH) ? 34 : 10;
Perhaps you could, instead, use the frequency shift to calculate the
strength between 34 and 10.
So, assuming that you take my suggestion of returning a value from 0 to 100,
and such value is stored at a "shift" var, you could do:
*strength = 34 - 24 * shift / 100;
(ok, a linear interpolation is not what would happen on a real case, but
as the goal of a virtual driver is to validate if userspace is doing the
right thing, this works just fine).
> + return 0;
> +}
> +
> +static int dvb_dummy_tuner_init(struct dvb_frontend *fe)
> +{
> + struct dvb_dummy_tuner_dev *tuner_dev = dvb_dummy_tuner_get_dev(fe);
> + struct dvb_dummy_tuner_config config = tuner_dev->config;
> +
> + msleep_interruptible(config.mock_power_up_delay_msec);
> +
> + tuner_dev->hw_state.power_status = STATUS_ACTIVE;
> + tuner_dev->hw_state.if_frequency = 5000;
> +
> + return 0;
> +}
> +
> +static int dvb_dummy_tuner_sleep(struct dvb_frontend *fe)
> +{
> + struct dvb_dummy_tuner_dev *tuner_dev = dvb_dummy_tuner_get_dev(fe);
> + struct dvb_dummy_tuner_config config = tuner_dev->config;
> +
> + msleep_interruptible(config.mock_sleep_delay_msec);
> + tuner_dev->hw_state.power_status = STATUS_ASLEEP;
> +
> + return 0;
> +}
> +
> +static int dvb_dummy_tuner_suspend(struct dvb_frontend *fe)
> +{
> + return dvb_dummy_tuner_sleep(fe);
> +}
> +
> +static int dvb_dummy_tuner_resume(struct dvb_frontend *fe)
> +{
> + struct dvb_dummy_tuner_dev *tuner_dev = dvb_dummy_tuner_get_dev(fe);
> + struct dvb_dummy_tuner_config config = tuner_dev->config;
> +
> + msleep_interruptible(config.mock_resume_delay_msec);
> + tuner_dev->hw_state.power_status = STATUS_ACTIVE;
> +
> + return 0;
> +}
For suspend/resume, I would not do any msleep(). Just set the status.
> +
> +static int dvb_dummy_tuner_set_params(struct dvb_frontend *fe)
> +{
> + struct dvb_dummy_tuner_dev *tuner_dev = dvb_dummy_tuner_get_dev(fe);
> + struct dvb_dummy_tuner_config config = tuner_dev->config;
> + struct dtv_frontend_properties *c = &fe->dtv_property_cache;
> + u32 min_freq = fe->ops.tuner_ops.info.frequency_min_hz;
> + u32 max_freq = fe->ops.tuner_ops.info.frequency_max_hz;
> + u32 min_bw = fe->ops.tuner_ops.info.bandwidth_min;
> + u32 max_bw = fe->ops.tuner_ops.info.bandwidth_max;
> +
> + msleep_interruptible(config.mock_tune_delay_msec);
> +
> + if (c->frequency < min_freq || c->frequency > max_freq ||
> + c->bandwidth_hz < min_bw || c->bandwidth_hz > max_bw) {
> + tuner_dev->hw_state.lock_status = STATUS_NO_LOCK;
> + return -EINVAL;
> + }
You can move the msleep() to be after checking the parameters.
This is what happens on other drivers.
> +
> + tuner_dev->hw_state.tuned_frequency = c->frequency;
> + tuner_dev->hw_state.bandwidth = c->bandwidth_hz;
> + tuner_dev->hw_state.lock_status = STATUS_LOCKED;
> +
> + return 0;
> +}
> +
> +static int dvb_dummy_tuner_set_config(struct dvb_frontend *fe,
> + void *priv_cfg)
> +{
> + struct dvb_dummy_tuner_dev *tuner_dev = dvb_dummy_tuner_get_dev(fe);
> +
> + WARN_ON(sizeof(tuner_dev->config) != sizeof(*priv_cfg));
> + memcpy(&tuner_dev->config, priv_cfg, sizeof(*priv_cfg));
Huh? sizeof(void *priv_config) seems plain wrong to me. The above
shold be, instead:
memcpy(&tuner_dev->config, priv_cfg, sizeof(tuner_dev->config));
but you should ensure that the caller driver will be filling it
properly there.
> +
> + return 0;
> +}
> +
> +static int dvb_dummy_tuner_get_frequency(struct dvb_frontend *fe,
> + u32 *frequency)
> +{
> + struct dvb_dummy_tuner_dev *tuner_dev = dvb_dummy_tuner_get_dev(fe);
> +
> + *frequency = tuner_dev->hw_state.tuned_frequency;
> +
> + return 0;
> +}
> +
> +static int dvb_dummy_tuner_get_bandwidth(struct dvb_frontend *fe,
> + u32 *bandwidth)
> +{
> + struct dvb_dummy_tuner_dev *tuner_dev = dvb_dummy_tuner_get_dev(fe);
> +
> + *bandwidth = tuner_dev->hw_state.bandwidth;
> +
> + return 0;
> +}
> +
> +static int dvb_dummy_tuner_get_if_frequency(struct dvb_frontend *fe,
> + u32 *frequency)
> +{
> + struct dvb_dummy_tuner_dev *tuner_dev = dvb_dummy_tuner_get_dev(fe);
> +
> + *frequency = tuner_dev->hw_state.if_frequency;
> +
> + return 0;
> +}
> +
> +static int dvb_dummy_tuner_get_status(struct dvb_frontend *fe, u32 *status)
> +{
> + struct dvb_dummy_tuner_dev *tuner_dev = dvb_dummy_tuner_get_dev(fe);
> +
> + *status = tuner_dev->hw_state.lock_status;
> +
> + return 0;
> +}
> +
> +static const struct dvb_tuner_ops dvb_dummy_tuner_ops = {
> + .init = dvb_dummy_tuner_init,
> + .sleep = dvb_dummy_tuner_sleep,
> + .suspend = dvb_dummy_tuner_suspend,
> + .resume = dvb_dummy_tuner_resume,
> + .set_params = dvb_dummy_tuner_set_params,
> + .set_config = dvb_dummy_tuner_set_config,
> + .get_bandwidth = dvb_dummy_tuner_get_bandwidth,
> + .get_frequency = dvb_dummy_tuner_get_frequency,
> + .get_if_frequency = dvb_dummy_tuner_get_if_frequency,
> + .get_status = dvb_dummy_tuner_get_status,
> + .get_rf_strength = dvb_dummy_tuner_get_signal_strength
> +};
> +
> +static const struct i2c_device_id dvb_dummy_tuner_i2c_id_table[] = {
> + {"dvb_dummy_tuner", 0},
> + {}
> +};
> +MODULE_DEVICE_TABLE(i2c, dvb_dummy_tuner_i2c_id_table);
> +
> +static int dvb_dummy_tuner_i2c_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct dvb_dummy_tuner_config *config = client->dev.platform_data;
> + struct dvb_frontend *fe = config->fe;
> + struct dvb_dummy_tuner_dev *tuner_dev = NULL;
> +
> + tuner_dev = kzalloc(sizeof(*tuner_dev), GFP_KERNEL);
> + if (!tuner_dev)
> + return -ENOMEM;
> +
> + tuner_dev->fe = config->fe;
> + i2c_set_clientdata(client, tuner_dev);
> +
> + memcpy(&fe->ops.tuner_ops,
> + &dvb_dummy_tuner_ops,
> + sizeof(struct dvb_tuner_ops));
> +
> + fe->tuner_priv = client;
> +
> + return 0;
> +}
> +
> +static int dvb_dummy_tuner_i2c_remove(struct i2c_client *client)
> +{
> + struct dvb_dummy_tuner_dev *tuner_dev = i2c_get_clientdata(client);
> + struct dvb_frontend *fe = tuner_dev->fe;
> +
> + memset(&fe->ops.tuner_ops, 0, sizeof(struct dvb_tuner_ops));
> + fe->tuner_priv = NULL;
> + kfree(tuner_dev);
> +
> + return 0;
> +}
> +
> +static struct i2c_driver dvb_dummy_tuner_i2c_driver = {
> + .driver = {
> + .name = "dvb_dummy_tuner",
> + .suppress_bind_attrs = true,
> + },
> + .probe = dvb_dummy_tuner_i2c_probe,
> + .remove = dvb_dummy_tuner_i2c_remove,
> + .id_table = dvb_dummy_tuner_i2c_id_table,
> +};
> +module_i2c_driver(dvb_dummy_tuner_i2c_driver);
> +
> +MODULE_DESCRIPTION("DVB Dummy Tuner");
> +MODULE_AUTHOR("Daniel W. S. Almeida");
> +MODULE_LICENSE("GPL");
Thanks,
Mauro
