1// SPDX-License-Identifier: GPL-2.0
2/*
3 * The Virtual DTV test driver serves as a reference DVB driver and helps
4 * validate the existing APIs in the media subsystem. It can also aid
5 * developers working on userspace applications.
6 *
7 * When this module is loaded, it will attempt to modprobe 'dvb_vidtv_tuner'
8 * and 'dvb_vidtv_demod'.
9 *
10 * Copyright (C) 2020 Daniel W. S. Almeida
11 */
12
13#include <linux/dev_printk.h>
14#include <linux/moduleparam.h>
15#include <linux/mutex.h>
16#include <linux/platform_device.h>
17#include <linux/time.h>
18#include <linux/types.h>
19#include <linux/workqueue.h>
20
21#include "vidtv_bridge.h"
22#include "vidtv_common.h"
23#include "vidtv_demod.h"
24#include "vidtv_mux.h"
25#include "vidtv_ts.h"
26#include "vidtv_tuner.h"
27
28#define MUX_BUF_MIN_SZ 90164
29#define MUX_BUF_MAX_SZ (MUX_BUF_MIN_SZ * 10)
30#define TUNER_DEFAULT_ADDR 0x68
31#define DEMOD_DEFAULT_ADDR 0x60
32#define VIDTV_DEFAULT_NETWORK_ID 0xff44
33#define VIDTV_DEFAULT_NETWORK_NAME "LinuxTV.org"
34#define VIDTV_DEFAULT_TS_ID 0x4081
35
36/*
37 * The LNBf fake parameters here are the ranges used by an
38 * Universal (extended) European LNBf, which is likely the most common LNBf
39 * found on Satellite digital TV system nowadays.
40 */
41#define LNB_CUT_FREQUENCY	11700000	/* high IF frequency */
42#define LNB_LOW_FREQ		9750000		/* low IF frequency */
43#define LNB_HIGH_FREQ		10600000	/* transition frequency */
44
45static unsigned int drop_tslock_prob_on_low_snr;
46module_param(drop_tslock_prob_on_low_snr, uint, 0);
47MODULE_PARM_DESC(drop_tslock_prob_on_low_snr,
48		 "Probability of losing the TS lock if the signal quality is bad");
49
50static unsigned int recover_tslock_prob_on_good_snr;
51module_param(recover_tslock_prob_on_good_snr, uint, 0);
52MODULE_PARM_DESC(recover_tslock_prob_on_good_snr,
53		 "Probability recovering the TS lock when the signal improves");
54
55static unsigned int mock_power_up_delay_msec;
56module_param(mock_power_up_delay_msec, uint, 0);
57MODULE_PARM_DESC(mock_power_up_delay_msec, "Simulate a power up delay");
58
59static unsigned int mock_tune_delay_msec;
60module_param(mock_tune_delay_msec, uint, 0);
61MODULE_PARM_DESC(mock_tune_delay_msec, "Simulate a tune delay");
62
63static unsigned int vidtv_valid_dvb_t_freqs[NUM_VALID_TUNER_FREQS] = {
64	474000000
65};
66
67module_param_array(vidtv_valid_dvb_t_freqs, uint, NULL, 0);
68MODULE_PARM_DESC(vidtv_valid_dvb_t_freqs,
69		 "Valid DVB-T frequencies to simulate, in Hz");
70
71static unsigned int vidtv_valid_dvb_c_freqs[NUM_VALID_TUNER_FREQS] = {
72	474000000
73};
74
75module_param_array(vidtv_valid_dvb_c_freqs, uint, NULL, 0);
76MODULE_PARM_DESC(vidtv_valid_dvb_c_freqs,
77		 "Valid DVB-C frequencies to simulate, in Hz");
78
79static unsigned int vidtv_valid_dvb_s_freqs[NUM_VALID_TUNER_FREQS] = {
80	11362000
81};
82module_param_array(vidtv_valid_dvb_s_freqs, uint, NULL, 0);
83MODULE_PARM_DESC(vidtv_valid_dvb_s_freqs,
84		 "Valid DVB-S/S2 frequencies to simulate at Ku-Band, in kHz");
85
86static unsigned int max_frequency_shift_hz;
87module_param(max_frequency_shift_hz, uint, 0);
88MODULE_PARM_DESC(max_frequency_shift_hz,
89		 "Maximum shift in HZ allowed when tuning in a channel");
90
91DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nums);
92
93/*
94 * Influences the signal acquisition time. See ISO/IEC 13818-1 : 2000. p. 113.
95 */
96static unsigned int si_period_msec = 40;
97module_param(si_period_msec, uint, 0);
98MODULE_PARM_DESC(si_period_msec, "How often to send SI packets. Default: 40ms");
99
100static unsigned int pcr_period_msec = 40;
101module_param(pcr_period_msec, uint, 0);
102MODULE_PARM_DESC(pcr_period_msec,
103		 "How often to send PCR packets. Default: 40ms");
104
105static unsigned int mux_rate_kbytes_sec = 4096;
106module_param(mux_rate_kbytes_sec, uint, 0);
107MODULE_PARM_DESC(mux_rate_kbytes_sec, "Mux rate: will pad stream if below");
108
109static unsigned int pcr_pid = 0x200;
110module_param(pcr_pid, uint, 0);
111MODULE_PARM_DESC(pcr_pid, "PCR PID for all channels: defaults to 0x200");
112
113static unsigned int mux_buf_sz_pkts;
114module_param(mux_buf_sz_pkts, uint, 0);
115MODULE_PARM_DESC(mux_buf_sz_pkts,
116		 "Size for the internal mux buffer in multiples of 188 bytes");
117
118static u32 vidtv_bridge_mux_buf_sz_for_mux_rate(void)
119{
120	u32 max_elapsed_time_msecs =  VIDTV_MAX_SLEEP_USECS / USEC_PER_MSEC;
121	u32 mux_buf_sz = mux_buf_sz_pkts * TS_PACKET_LEN;
122	u32 nbytes_expected;
123
124	nbytes_expected = mux_rate_kbytes_sec;
125	nbytes_expected *= max_elapsed_time_msecs;
126
127	mux_buf_sz = roundup(nbytes_expected, TS_PACKET_LEN);
128	mux_buf_sz += mux_buf_sz / 10;
129
130	if (mux_buf_sz < MUX_BUF_MIN_SZ)
131		mux_buf_sz = MUX_BUF_MIN_SZ;
132
133	if (mux_buf_sz > MUX_BUF_MAX_SZ)
134		mux_buf_sz = MUX_BUF_MAX_SZ;
135
136	return mux_buf_sz;
137}
138
139static bool vidtv_bridge_check_demod_lock(struct vidtv_dvb *dvb, u32 n)
140{
141	enum fe_status status;
142
143	dvb->fe[n]->ops.read_status(dvb->fe[n], &status);
144
145	return status == (FE_HAS_SIGNAL  |
146			  FE_HAS_CARRIER |
147			  FE_HAS_VITERBI |
148			  FE_HAS_SYNC    |
149			  FE_HAS_LOCK);
150}
151
152/*
153 * called on a separate thread by the mux when new packets become available
154 */
155static void vidtv_bridge_on_new_pkts_avail(void *priv, u8 *buf, u32 npkts)
156{
157	struct vidtv_dvb *dvb = priv;
158
159	/* drop packets if we lose the lock */
160	if (vidtv_bridge_check_demod_lock(dvb, 0))
161		dvb_dmx_swfilter_packets(&dvb->demux, buf, npkts);
162}
163
164static int vidtv_start_streaming(struct vidtv_dvb *dvb)
165{
166	struct vidtv_mux_init_args mux_args = {
167		.mux_rate_kbytes_sec         = mux_rate_kbytes_sec,
168		.on_new_packets_available_cb = vidtv_bridge_on_new_pkts_avail,
169		.pcr_period_usecs            = pcr_period_msec * USEC_PER_MSEC,
170		.si_period_usecs             = si_period_msec * USEC_PER_MSEC,
171		.pcr_pid                     = pcr_pid,
172		.transport_stream_id         = VIDTV_DEFAULT_TS_ID,
173		.network_id                  = VIDTV_DEFAULT_NETWORK_ID,
174		.network_name                = VIDTV_DEFAULT_NETWORK_NAME,
175		.priv                        = dvb,
176	};
177	struct device *dev = &dvb->pdev->dev;
178	u32 mux_buf_sz;
179
180	if (dvb->streaming) {
181		dev_warn_ratelimited(dev, "Already streaming. Skipping.\n");
182		return 0;
183	}
184
185	if (mux_buf_sz_pkts)
186		mux_buf_sz = mux_buf_sz_pkts;
187	else
188		mux_buf_sz = vidtv_bridge_mux_buf_sz_for_mux_rate();
189
190	mux_args.mux_buf_sz  = mux_buf_sz;
191
192	dvb->streaming = true;
193	dvb->mux = vidtv_mux_init(dvb->fe[0], dev, &mux_args);
194	if (!dvb->mux)
195		return -ENOMEM;
196	vidtv_mux_start_thread(dvb->mux);
197
198	dev_dbg_ratelimited(dev, "Started streaming\n");
199	return 0;
200}
201
202static int vidtv_stop_streaming(struct vidtv_dvb *dvb)
203{
204	struct device *dev = &dvb->pdev->dev;
205
206	dvb->streaming = false;
207	vidtv_mux_stop_thread(dvb->mux);
208	vidtv_mux_destroy(dvb->mux);
209	dvb->mux = NULL;
210
211	dev_dbg_ratelimited(dev, "Stopped streaming\n");
212	return 0;
213}
214
215static int vidtv_start_feed(struct dvb_demux_feed *feed)
216{
217	struct dvb_demux *demux = feed->demux;
218	struct vidtv_dvb *dvb   = demux->priv;
219	int ret;
220	int rc;
221
222	if (!demux->dmx.frontend)
223		return -EINVAL;
224
225	mutex_lock(&dvb->feed_lock);
226
227	dvb->nfeeds++;
228	rc = dvb->nfeeds;
229
230	if (dvb->nfeeds == 1) {
231		ret = vidtv_start_streaming(dvb);
232		if (ret < 0)
233			rc = ret;
234	}
235
236	mutex_unlock(&dvb->feed_lock);
237	return rc;
238}
239
240static int vidtv_stop_feed(struct dvb_demux_feed *feed)
241{
242	struct dvb_demux *demux = feed->demux;
243	struct vidtv_dvb *dvb   = demux->priv;
244	int err = 0;
245
246	mutex_lock(&dvb->feed_lock);
247	dvb->nfeeds--;
248
249	if (!dvb->nfeeds)
250		err = vidtv_stop_streaming(dvb);
251
252	mutex_unlock(&dvb->feed_lock);
253	return err;
254}
255
256static struct dvb_frontend *vidtv_get_frontend_ptr(struct i2c_client *c)
257{
258	struct vidtv_demod_state *state = i2c_get_clientdata(c);
259
260	/* the demod will set this when its probe function runs */
261	return &state->frontend;
262}
263
264static int vidtv_master_xfer(struct i2c_adapter *i2c_adap,
265			     struct i2c_msg msgs[],
266			     int num)
267{
268	/*
269	 * Right now, this virtual driver doesn't really send or receive
270	 * messages from I2C. A real driver will require an implementation
271	 * here.
272	 */
273	return 0;
274}
275
276static u32 vidtv_i2c_func(struct i2c_adapter *adapter)
277{
278	return I2C_FUNC_I2C;
279}
280
281static const struct i2c_algorithm vidtv_i2c_algorithm = {
282	.master_xfer   = vidtv_master_xfer,
283	.functionality = vidtv_i2c_func,
284};
285
286static int vidtv_bridge_i2c_register_adap(struct vidtv_dvb *dvb)
287{
288	struct i2c_adapter *i2c_adapter = &dvb->i2c_adapter;
289
290	strscpy(i2c_adapter->name, "vidtv_i2c", sizeof(i2c_adapter->name));
291	i2c_adapter->owner      = THIS_MODULE;
292	i2c_adapter->algo       = &vidtv_i2c_algorithm;
293	i2c_adapter->algo_data  = NULL;
294	i2c_adapter->timeout    = 500;
295	i2c_adapter->retries    = 3;
296	i2c_adapter->dev.parent = &dvb->pdev->dev;
297
298	i2c_set_adapdata(i2c_adapter, dvb);
299	return i2c_add_adapter(&dvb->i2c_adapter);
300}
301
302static int vidtv_bridge_register_adap(struct vidtv_dvb *dvb)
303{
304	int ret = 0;
305
306	ret = dvb_register_adapter(&dvb->adapter,
307				   KBUILD_MODNAME,
308				   THIS_MODULE,
309				   &dvb->i2c_adapter.dev,
310				   adapter_nums);
311
312	return ret;
313}
314
315static int vidtv_bridge_dmx_init(struct vidtv_dvb *dvb)
316{
317	dvb->demux.dmx.capabilities = DMX_TS_FILTERING |
318				      DMX_SECTION_FILTERING;
319
320	dvb->demux.priv       = dvb;
321	dvb->demux.filternum  = 256;
322	dvb->demux.feednum    = 256;
323	dvb->demux.start_feed = vidtv_start_feed;
324	dvb->demux.stop_feed  = vidtv_stop_feed;
325
326	return dvb_dmx_init(&dvb->demux);
327}
328
329static int vidtv_bridge_dmxdev_init(struct vidtv_dvb *dvb)
330{
331	dvb->dmx_dev.filternum    = 256;
332	dvb->dmx_dev.demux        = &dvb->demux.dmx;
333	dvb->dmx_dev.capabilities = 0;
334
335	return dvb_dmxdev_init(&dvb->dmx_dev, &dvb->adapter);
336}
337
338static int vidtv_bridge_probe_demod(struct vidtv_dvb *dvb, u32 n)
339{
340	struct vidtv_demod_config cfg = {
341		.drop_tslock_prob_on_low_snr     = drop_tslock_prob_on_low_snr,
342		.recover_tslock_prob_on_good_snr = recover_tslock_prob_on_good_snr,
343	};
344	dvb->i2c_client_demod[n] = dvb_module_probe("dvb_vidtv_demod",
345						    NULL,
346						    &dvb->i2c_adapter,
347						    DEMOD_DEFAULT_ADDR,
348						    &cfg);
349
350	/* driver will not work anyways so bail out */
351	if (!dvb->i2c_client_demod[n])
352		return -ENODEV;
353
354	/* retrieve a ptr to the frontend state */
355	dvb->fe[n] = vidtv_get_frontend_ptr(dvb->i2c_client_demod[n]);
356
357	return 0;
358}
359
360static int vidtv_bridge_probe_tuner(struct vidtv_dvb *dvb, u32 n)
361{
362	struct vidtv_tuner_config cfg = {
363		.fe                       = dvb->fe[n],
364		.mock_power_up_delay_msec = mock_power_up_delay_msec,
365		.mock_tune_delay_msec     = mock_tune_delay_msec,
366	};
367	u32 freq;
368	int i;
369
370	/* TODO: check if the frequencies are at a valid range */
371
372	memcpy(cfg.vidtv_valid_dvb_t_freqs,
373	       vidtv_valid_dvb_t_freqs,
374	       sizeof(vidtv_valid_dvb_t_freqs));
375
376	memcpy(cfg.vidtv_valid_dvb_c_freqs,
377	       vidtv_valid_dvb_c_freqs,
378	       sizeof(vidtv_valid_dvb_c_freqs));
379
380	/*
381	 * Convert Satellite frequencies from Ku-band in kHZ into S-band
382	 * frequencies in Hz.
383	 */
384	for (i = 0; i < ARRAY_SIZE(vidtv_valid_dvb_s_freqs); i++) {
385		freq = vidtv_valid_dvb_s_freqs[i];
386		if (freq) {
387			if (freq < LNB_CUT_FREQUENCY)
388				freq = abs(freq - LNB_LOW_FREQ);
389			else
390				freq = abs(freq - LNB_HIGH_FREQ);
391		}
392		cfg.vidtv_valid_dvb_s_freqs[i] = freq;
393	}
394
395	cfg.max_frequency_shift_hz = max_frequency_shift_hz;
396
397	dvb->i2c_client_tuner[n] = dvb_module_probe("dvb_vidtv_tuner",
398						    NULL,
399						    &dvb->i2c_adapter,
400						    TUNER_DEFAULT_ADDR,
401						    &cfg);
402
403	return (dvb->i2c_client_tuner[n]) ? 0 : -ENODEV;
404}
405
406static int vidtv_bridge_dvb_init(struct vidtv_dvb *dvb)
407{
408	int ret, i, j;
409
410	ret = vidtv_bridge_i2c_register_adap(dvb);
411	if (ret < 0)
412		goto fail_i2c;
413
414	ret = vidtv_bridge_register_adap(dvb);
415	if (ret < 0)
416		goto fail_adapter;
417
418	for (i = 0; i < NUM_FE; ++i) {
419		ret = vidtv_bridge_probe_demod(dvb, i);
420		if (ret < 0)
421			goto fail_demod_probe;
422
423		ret = vidtv_bridge_probe_tuner(dvb, i);
424		if (ret < 0)
425			goto fail_tuner_probe;
426
427		ret = dvb_register_frontend(&dvb->adapter, dvb->fe[i]);
428		if (ret < 0)
429			goto fail_fe;
430	}
431
432	ret = vidtv_bridge_dmx_init(dvb);
433	if (ret < 0)
434		goto fail_dmx;
435
436	ret = vidtv_bridge_dmxdev_init(dvb);
437	if (ret < 0)
438		goto fail_dmx_dev;
439
440	for (j = 0; j < NUM_FE; ++j) {
441		ret = dvb->demux.dmx.connect_frontend(&dvb->demux.dmx,
442						      &dvb->dmx_fe[j]);
443		if (ret < 0)
444			goto fail_dmx_conn;
445
446		/*
447		 * The source of the demux is a frontend connected
448		 * to the demux.
449		 */
450		dvb->dmx_fe[j].source = DMX_FRONTEND_0;
451	}
452
453	return ret;
454
455fail_dmx_conn:
456	for (j = j - 1; j >= 0; --j)
457		dvb->demux.dmx.remove_frontend(&dvb->demux.dmx,
458					       &dvb->dmx_fe[j]);
459	dvb_dmxdev_release(&dvb->dmx_dev);
460fail_dmx_dev:
461	dvb_dmx_release(&dvb->demux);
462fail_dmx:
463fail_demod_probe:
464	for (i = i - 1; i >= 0; --i) {
465		dvb_unregister_frontend(dvb->fe[i]);
466fail_fe:
467		dvb_module_release(dvb->i2c_client_tuner[i]);
468fail_tuner_probe:
469		dvb_module_release(dvb->i2c_client_demod[i]);
470	}
471fail_adapter:
472	dvb_unregister_adapter(&dvb->adapter);
473fail_i2c:
474	i2c_del_adapter(&dvb->i2c_adapter);
475
476	return ret;
477}
478
479static int vidtv_bridge_probe(struct platform_device *pdev)
480{
481	struct vidtv_dvb *dvb;
482	int ret;
483
484	dvb = kzalloc(sizeof(*dvb), GFP_KERNEL);
485	if (!dvb)
486		return -ENOMEM;
487
488	dvb->pdev = pdev;
489
490	ret = vidtv_bridge_dvb_init(dvb);
491	if (ret < 0)
492		goto err_dvb;
493
494	mutex_init(&dvb->feed_lock);
495
496	platform_set_drvdata(pdev, dvb);
497
498	dev_info(&pdev->dev, "Successfully initialized vidtv!\n");
499	return ret;
500
501err_dvb:
502	kfree(dvb);
503	return ret;
504}
505
506static int vidtv_bridge_remove(struct platform_device *pdev)
507{
508	struct vidtv_dvb *dvb;
509	u32 i;
510
511	dvb = platform_get_drvdata(pdev);
512
513	mutex_destroy(&dvb->feed_lock);
514
515	for (i = 0; i < NUM_FE; ++i) {
516		dvb_unregister_frontend(dvb->fe[i]);
517		dvb_module_release(dvb->i2c_client_tuner[i]);
518		dvb_module_release(dvb->i2c_client_demod[i]);
519	}
520
521	dvb_dmxdev_release(&dvb->dmx_dev);
522	dvb_dmx_release(&dvb->demux);
523	dvb_unregister_adapter(&dvb->adapter);
524
525	return 0;
526}
527
528static void vidtv_bridge_dev_release(struct device *dev)
529{
530}
531
532static struct platform_device vidtv_bridge_dev = {
533	.name		= "vidtv_bridge",
534	.dev.release	= vidtv_bridge_dev_release,
535};
536
537static struct platform_driver vidtv_bridge_driver = {
538	.driver = {
539		.name                = "vidtv_bridge",
540		.suppress_bind_attrs = true,
541	},
542	.probe    = vidtv_bridge_probe,
543	.remove   = vidtv_bridge_remove,
544};
545
546static void __exit vidtv_bridge_exit(void)
547{
548	platform_driver_unregister(&vidtv_bridge_driver);
549	platform_device_unregister(&vidtv_bridge_dev);
550}
551
552static int __init vidtv_bridge_init(void)
553{
554	int ret;
555
556	ret = platform_device_register(&vidtv_bridge_dev);
557	if (ret)
558		return ret;
559
560	ret = platform_driver_register(&vidtv_bridge_driver);
561	if (ret)
562		platform_device_unregister(&vidtv_bridge_dev);
563
564	return ret;
565}
566
567module_init(vidtv_bridge_init);
568module_exit(vidtv_bridge_exit);
569
570MODULE_DESCRIPTION("Virtual Digital TV Test Driver");
571MODULE_AUTHOR("Daniel W. S. Almeida");
572MODULE_LICENSE("GPL");
573MODULE_ALIAS("vidtv");
574MODULE_ALIAS("dvb_vidtv");
575