summaryrefslogtreecommitdiffstats
path: root/drivers/media/rc/rc-ir-raw.c
blob: 18504870b9f05b9bbb086ac776a519c560139387 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
// SPDX-License-Identifier: GPL-2.0
// rc-ir-raw.c - handle IR pulse/space events
//
// Copyright (C) 2010 by Mauro Carvalho Chehab

#include <linux/export.h>
#include <linux/kthread.h>
#include <linux/mutex.h>
#include <linux/kmod.h>
#include <linux/sched.h>
#include "rc-core-priv.h"

/* Used to keep track of IR raw clients, protected by ir_raw_handler_lock */
static LIST_HEAD(ir_raw_client_list);

/* Used to handle IR raw handler extensions */
static DEFINE_MUTEX(ir_raw_handler_lock);
static LIST_HEAD(ir_raw_handler_list);
static atomic64_t available_protocols = ATOMIC64_INIT(0);

static int ir_raw_event_thread(void *data)
{
	struct ir_raw_event ev;
	struct ir_raw_handler *handler;
	struct ir_raw_event_ctrl *raw = (struct ir_raw_event_ctrl *)data;

	while (1) {
		mutex_lock(&ir_raw_handler_lock);
		while (kfifo_out(&raw->kfifo, &ev, 1)) {
			list_for_each_entry(handler, &ir_raw_handler_list, list)
				if (raw->dev->enabled_protocols &
				    handler->protocols || !handler->protocols)
					handler->decode(raw->dev, ev);
			ir_lirc_raw_event(raw->dev, ev);
			raw->prev_ev = ev;
		}
		mutex_unlock(&ir_raw_handler_lock);

		set_current_state(TASK_INTERRUPTIBLE);

		if (kthread_should_stop()) {
			__set_current_state(TASK_RUNNING);
			break;
		} else if (!kfifo_is_empty(&raw->kfifo))
			set_current_state(TASK_RUNNING);

		schedule();
	}

	return 0;
}

/**
 * ir_raw_event_store() - pass a pulse/space duration to the raw ir decoders
 * @dev:	the struct rc_dev device descriptor
 * @ev:		the struct ir_raw_event descriptor of the pulse/space
 *
 * This routine (which may be called from an interrupt context) stores a
 * pulse/space duration for the raw ir decoding state machines. Pulses are
 * signalled as positive values and spaces as negative values. A zero value
 * will reset the decoding state machines.
 */
int ir_raw_event_store(struct rc_dev *dev, struct ir_raw_event *ev)
{
	if (!dev->raw)
		return -EINVAL;

	IR_dprintk(2, "sample: (%05dus %s)\n",
		   TO_US(ev->duration), TO_STR(ev->pulse));

	if (!kfifo_put(&dev->raw->kfifo, *ev)) {
		dev_err(&dev->dev, "IR event FIFO is full!\n");
		return -ENOSPC;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(ir_raw_event_store);

/**
 * ir_raw_event_store_edge() - notify raw ir decoders of the start of a pulse/space
 * @dev:	the struct rc_dev device descriptor
 * @pulse:	true for pulse, false for space
 *
 * This routine (which may be called from an interrupt context) is used to
 * store the beginning of an ir pulse or space (or the start/end of ir
 * reception) for the raw ir decoding state machines. This is used by
 * hardware which does not provide durations directly but only interrupts
 * (or similar events) on state change.
 */
int ir_raw_event_store_edge(struct rc_dev *dev, bool pulse)
{
	ktime_t			now;
	DEFINE_IR_RAW_EVENT(ev);
	int			rc = 0;

	if (!dev->raw)
		return -EINVAL;

	now = ktime_get();
	ev.duration = ktime_to_ns(ktime_sub(now, dev->raw->last_event));
	ev.pulse = !pulse;

	rc = ir_raw_event_store(dev, &ev);

	dev->raw->last_event = now;

	/* timer could be set to timeout (125ms by default) */
	if (!timer_pending(&dev->raw->edge_handle) ||
	    time_after(dev->raw->edge_handle.expires,
		       jiffies + msecs_to_jiffies(15))) {
		mod_timer(&dev->raw->edge_handle,
			  jiffies + msecs_to_jiffies(15));
	}

	return rc;
}
EXPORT_SYMBOL_GPL(ir_raw_event_store_edge);

/**
 * ir_raw_event_store_with_filter() - pass next pulse/space to decoders with some processing
 * @dev:	the struct rc_dev device descriptor
 * @ev:		the event that has occurred
 *
 * This routine (which may be called from an interrupt context) works
 * in similar manner to ir_raw_event_store_edge.
 * This routine is intended for devices with limited internal buffer
 * It automerges samples of same type, and handles timeouts. Returns non-zero
 * if the event was added, and zero if the event was ignored due to idle
 * processing.
 */
int ir_raw_event_store_with_filter(struct rc_dev *dev, struct ir_raw_event *ev)
{
	if (!dev->raw)
		return -EINVAL;

	/* Ignore spaces in idle mode */
	if (dev->idle && !ev->pulse)
		return 0;
	else if (dev->idle)
		ir_raw_event_set_idle(dev, false);

	if (!dev->raw->this_ev.duration)
		dev->raw->this_ev = *ev;
	else if (ev->pulse == dev->raw->this_ev.pulse)
		dev->raw->this_ev.duration += ev->duration;
	else {
		ir_raw_event_store(dev, &dev->raw->this_ev);
		dev->raw->this_ev = *ev;
	}

	/* Enter idle mode if nessesary */
	if (!ev->pulse && dev->timeout &&
	    dev->raw->this_ev.duration >= dev->timeout)
		ir_raw_event_set_idle(dev, true);

	return 1;
}
EXPORT_SYMBOL_GPL(ir_raw_event_store_with_filter);

/**
 * ir_raw_event_set_idle() - provide hint to rc-core when the device is idle or not
 * @dev:	the struct rc_dev device descriptor
 * @idle:	whether the device is idle or not
 */
void ir_raw_event_set_idle(struct rc_dev *dev, bool idle)
{
	if (!dev->raw)
		return;

	IR_dprintk(2, "%s idle mode\n", idle ? "enter" : "leave");

	if (idle) {
		dev->raw->this_ev.timeout = true;
		ir_raw_event_store(dev, &dev->raw->this_ev);
		init_ir_raw_event(&dev->raw->this_ev);
	}

	if (dev->s_idle)
		dev->s_idle(dev, idle);

	dev->idle = idle;
}
EXPORT_SYMBOL_GPL(ir_raw_event_set_idle);

/**
 * ir_raw_event_handle() - schedules the decoding of stored ir data
 * @dev:	the struct rc_dev device descriptor
 *
 * This routine will tell rc-core to start decoding stored ir data.
 */
void ir_raw_event_handle(struct rc_dev *dev)
{
	if (!dev->raw || !dev->raw->thread)
		return;

	wake_up_process(dev->raw->thread);
}
EXPORT_SYMBOL_GPL(ir_raw_event_handle);

/* used internally by the sysfs interface */
u64
ir_raw_get_allowed_protocols(void)
{
	return atomic64_read(&available_protocols);
}

static int change_protocol(struct rc_dev *dev, u64 *rc_proto)
{
	/* the caller will update dev->enabled_protocols */
	return 0;
}

static void ir_raw_disable_protocols(struct rc_dev *dev, u64 protocols)
{
	mutex_lock(&dev->lock);
	dev->enabled_protocols &= ~protocols;
	mutex_unlock(&dev->lock);
}

/**
 * ir_raw_gen_manchester() - Encode data with Manchester (bi-phase) modulation.
 * @ev:		Pointer to pointer to next free event. *@ev is incremented for
 *		each raw event filled.
 * @max:	Maximum number of raw events to fill.
 * @timings:	Manchester modulation timings.
 * @n:		Number of bits of data.
 * @data:	Data bits to encode.
 *
 * Encodes the @n least significant bits of @data using Manchester (bi-phase)
 * modulation with the timing characteristics described by @timings, writing up
 * to @max raw IR events using the *@ev pointer.
 *
 * Returns:	0 on success.
 *		-ENOBUFS if there isn't enough space in the array to fit the
 *		full encoded data. In this case all @max events will have been
 *		written.
 */
int ir_raw_gen_manchester(struct ir_raw_event **ev, unsigned int max,
			  const struct ir_raw_timings_manchester *timings,
			  unsigned int n, u64 data)
{
	bool need_pulse;
	u64 i;
	int ret = -ENOBUFS;

	i = BIT_ULL(n - 1);

	if (timings->leader_pulse) {
		if (!max--)
			return ret;
		init_ir_raw_event_duration((*ev), 1, timings->leader_pulse);
		if (timings->leader_space) {
			if (!max--)
				return ret;
			init_ir_raw_event_duration(++(*ev), 0,
						   timings->leader_space);
		}
	} else {
		/* continue existing signal */
		--(*ev);
	}
	/* from here on *ev will point to the last event rather than the next */

	while (n && i > 0) {
		need_pulse = !(data & i);
		if (timings->invert)
			need_pulse = !need_pulse;
		if (need_pulse == !!(*ev)->pulse) {
			(*ev)->duration += timings->clock;
		} else {
			if (!max--)
				goto nobufs;
			init_ir_raw_event_duration(++(*ev), need_pulse,
						   timings->clock);
		}

		if (!max--)
			goto nobufs;
		init_ir_raw_event_duration(++(*ev), !need_pulse,
					   timings->clock);
		i >>= 1;
	}

	if (timings->trailer_space) {
		if (!(*ev)->pulse)
			(*ev)->duration += timings->trailer_space;
		else if (!max--)
			goto nobufs;
		else
			init_ir_raw_event_duration(++(*ev), 0,
						   timings->trailer_space);
	}

	ret = 0;
nobufs:
	/* point to the next event rather than last event before returning */
	++(*ev);
	return ret;
}
EXPORT_SYMBOL(ir_raw_gen_manchester);

/**
 * ir_raw_gen_pd() - Encode data to raw events with pulse-distance modulation.
 * @ev:		Pointer to pointer to next free event. *@ev is incremented for
 *		each raw event filled.
 * @max:	Maximum number of raw events to fill.
 * @timings:	Pulse distance modulation timings.
 * @n:		Number of bits of data.
 * @data:	Data bits to encode.
 *
 * Encodes the @n least significant bits of @data using pulse-distance
 * modulation with the timing characteristics described by @timings, writing up
 * to @max raw IR events using the *@ev pointer.
 *
 * Returns:	0 on success.
 *		-ENOBUFS if there isn't enough space in the array to fit the
 *		full encoded data. In this case all @max events will have been
 *		written.
 */
int ir_raw_gen_pd(struct ir_raw_event **ev, unsigned int max,
		  const struct ir_raw_timings_pd *timings,
		  unsigned int n, u64 data)
{
	int i;
	int ret;
	unsigned int space;

	if (timings->header_pulse) {
		ret = ir_raw_gen_pulse_space(ev, &max, timings->header_pulse,
					     timings->header_space);
		if (ret)
			return ret;
	}

	if (timings->msb_first) {
		for (i = n - 1; i >= 0; --i) {
			space = timings->bit_space[(data >> i) & 1];
			ret = ir_raw_gen_pulse_space(ev, &max,
						     timings->bit_pulse,
						     space);
			if (ret)
				return ret;
		}
	} else {
		for (i = 0; i < n; ++i, data >>= 1) {
			space = timings->bit_space[data & 1];
			ret = ir_raw_gen_pulse_space(ev, &max,
						     timings->bit_pulse,
						     space);
			if (ret)
				return ret;
		}
	}

	ret = ir_raw_gen_pulse_space(ev, &max, timings->trailer_pulse,
				     timings->trailer_space);
	return ret;
}
EXPORT_SYMBOL(ir_raw_gen_pd);

/**
 * ir_raw_gen_pl() - Encode data to raw events with pulse-length modulation.
 * @ev:		Pointer to pointer to next free event. *@ev is incremented for
 *		each raw event filled.
 * @max:	Maximum number of raw events to fill.
 * @timings:	Pulse distance modulation timings.
 * @n:		Number of bits of data.
 * @data:	Data bits to encode.
 *
 * Encodes the @n least significant bits of @data using space-distance
 * modulation with the timing characteristics described by @timings, writing up
 * to @max raw IR events using the *@ev pointer.
 *
 * Returns:	0 on success.
 *		-ENOBUFS if there isn't enough space in the array to fit the
 *		full encoded data. In this case all @max events will have been
 *		written.
 */
int ir_raw_gen_pl(struct ir_raw_event **ev, unsigned int max,
		  const struct ir_raw_timings_pl *timings,
		  unsigned int n, u64 data)
{
	int i;
	int ret = -ENOBUFS;
	unsigned int pulse;

	if (!max--)
		return ret;

	init_ir_raw_event_duration((*ev)++, 1, timings->header_pulse);

	if (timings->msb_first) {
		for (i = n - 1; i >= 0; --i) {
			if (!max--)
				return ret;
			init_ir_raw_event_duration((*ev)++, 0,
						   timings->bit_space);
			if (!max--)
				return ret;
			pulse = timings->bit_pulse[(data >> i) & 1];
			init_ir_raw_event_duration((*ev)++, 1, pulse);
		}
	} else {
		for (i = 0; i < n; ++i, data >>= 1) {
			if (!max--)
				return ret;
			init_ir_raw_event_duration((*ev)++, 0,
						   timings->bit_space);
			if (!max--)
				return ret;
			pulse = timings->bit_pulse[data & 1];
			init_ir_raw_event_duration((*ev)++, 1, pulse);
		}
	}

	if (!max--)
		return ret;

	init_ir_raw_event_duration((*ev)++, 0, timings->trailer_space);

	return 0;
}
EXPORT_SYMBOL(ir_raw_gen_pl);

/**
 * ir_raw_encode_scancode() - Encode a scancode as raw events
 *
 * @protocol:		protocol
 * @scancode:		scancode filter describing a single scancode
 * @events:		array of raw events to write into
 * @max:		max number of raw events
 *
 * Attempts to encode the scancode as raw events.
 *
 * Returns:	The number of events written.
 *		-ENOBUFS if there isn't enough space in the array to fit the
 *		encoding. In this case all @max events will have been written.
 *		-EINVAL if the scancode is ambiguous or invalid, or if no
 *		compatible encoder was found.
 */
int ir_raw_encode_scancode(enum rc_proto protocol, u32 scancode,
			   struct ir_raw_event *events, unsigned int max)
{
	struct ir_raw_handler *handler;
	int ret = -EINVAL;
	u64 mask = 1ULL << protocol;

	ir_raw_load_modules(&mask);

	mutex_lock(&ir_raw_handler_lock);
	list_for_each_entry(handler, &ir_raw_handler_list, list) {
		if (handler->protocols & mask && handler->encode) {
			ret = handler->encode(protocol, scancode, events, max);
			if (ret >= 0 || ret == -ENOBUFS)
				break;
		}
	}
	mutex_unlock(&ir_raw_handler_lock);

	return ret;
}
EXPORT_SYMBOL(ir_raw_encode_scancode);

static void edge_handle(struct timer_list *t)
{
	struct ir_raw_event_ctrl *raw = from_timer(raw, t, edge_handle);
	struct rc_dev *dev = raw->dev;
	ktime_t interval = ktime_sub(ktime_get(), dev->raw->last_event);

	if (ktime_to_ns(interval) >= dev->timeout) {
		DEFINE_IR_RAW_EVENT(ev);

		ev.timeout = true;
		ev.duration = ktime_to_ns(interval);

		ir_raw_event_store(dev, &ev);
	} else {
		mod_timer(&dev->raw->edge_handle,
			  jiffies + nsecs_to_jiffies(dev->timeout -
						     ktime_to_ns(interval)));
	}

	ir_raw_event_handle(dev);
}

/**
 * ir_raw_encode_carrier() - Get carrier used for protocol
 *
 * @protocol:		protocol
 *
 * Attempts to find the carrier for the specified protocol
 *
 * Returns:	The carrier in Hz
 *		-EINVAL if the protocol is invalid, or if no
 *		compatible encoder was found.
 */
int ir_raw_encode_carrier(enum rc_proto protocol)
{
	struct ir_raw_handler *handler;
	int ret = -EINVAL;
	u64 mask = BIT_ULL(protocol);

	mutex_lock(&ir_raw_handler_lock);
	list_for_each_entry(handler, &ir_raw_handler_list, list) {
		if (handler->protocols & mask && handler->encode) {
			ret = handler->carrier;
			break;
		}
	}
	mutex_unlock(&ir_raw_handler_lock);

	return ret;
}
EXPORT_SYMBOL(ir_raw_encode_carrier);

/*
 * Used to (un)register raw event clients
 */
int ir_raw_event_prepare(struct rc_dev *dev)
{
	if (!dev)
		return -EINVAL;

	dev->raw = kzalloc(sizeof(*dev->raw), GFP_KERNEL);
	if (!dev->raw)
		return -ENOMEM;

	dev->raw->dev = dev;
	dev->change_protocol = change_protocol;
	timer_setup(&dev->raw->edge_handle, edge_handle, 0);
	INIT_KFIFO(dev->raw->kfifo);

	return 0;
}

int ir_raw_event_register(struct rc_dev *dev)
{
	struct ir_raw_handler *handler;
	struct task_struct *thread;

	thread = kthread_run(ir_raw_event_thread, dev->raw, "rc%u", dev->minor);
	if (IS_ERR(thread))
		return PTR_ERR(thread);

	dev->raw->thread = thread;

	mutex_lock(&ir_raw_handler_lock);
	list_add_tail(&dev->raw->list, &ir_raw_client_list);
	list_for_each_entry(handler, &ir_raw_handler_list, list)
		if (handler->raw_register)
			handler->raw_register(dev);
	mutex_unlock(&ir_raw_handler_lock);

	return 0;
}

void ir_raw_event_free(struct rc_dev *dev)
{
	if (!dev)
		return;

	kfree(dev->raw);
	dev->raw = NULL;
}

void ir_raw_event_unregister(struct rc_dev *dev)
{
	struct ir_raw_handler *handler;

	if (!dev || !dev->raw)
		return;

	kthread_stop(dev->raw->thread);
	del_timer_sync(&dev->raw->edge_handle);

	mutex_lock(&ir_raw_handler_lock);
	list_del(&dev->raw->list);
	list_for_each_entry(handler, &ir_raw_handler_list, list)
		if (handler->raw_unregister)
			handler->raw_unregister(dev);
	mutex_unlock(&ir_raw_handler_lock);

	ir_raw_event_free(dev);
}

/*
 * Extension interface - used to register the IR decoders
 */

int ir_raw_handler_register(struct ir_raw_handler *ir_raw_handler)
{
	struct ir_raw_event_ctrl *raw;

	mutex_lock(&ir_raw_handler_lock);
	list_add_tail(&ir_raw_handler->list, &ir_raw_handler_list);
	if (ir_raw_handler->raw_register)
		list_for_each_entry(raw, &ir_raw_client_list, list)
			ir_raw_handler->raw_register(raw->dev);
	atomic64_or(ir_raw_handler->protocols, &available_protocols);
	mutex_unlock(&ir_raw_handler_lock);

	return 0;
}
EXPORT_SYMBOL(ir_raw_handler_register);

void ir_raw_handler_unregister(struct ir_raw_handler *ir_raw_handler)
{
	struct ir_raw_event_ctrl *raw;
	u64 protocols = ir_raw_handler->protocols;

	mutex_lock(&ir_raw_handler_lock);
	list_del(&ir_raw_handler->list);
	list_for_each_entry(raw, &ir_raw_client_list, list) {
		ir_raw_disable_protocols(raw->dev, protocols);
		if (ir_raw_handler->raw_unregister)
			ir_raw_handler->raw_unregister(raw->dev);
	}
	atomic64_andnot(protocols, &available_protocols);
	mutex_unlock(&ir_raw_handler_lock);
}
EXPORT_SYMBOL(ir_raw_handler_unregister);