Bootlin logo

Elixir Cross Referencer

  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
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
/*
 * LIRC base driver
 *
 * by Artur Lipowski <alipowski@interia.pl>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/device.h>
#include <linux/idr.h>
#include <linux/poll.h>
#include <linux/sched.h>
#include <linux/wait.h>

#include "rc-core-priv.h"
#include <uapi/linux/lirc.h>

#define LIRCBUF_SIZE	256

static dev_t lirc_base_dev;

/* Used to keep track of allocated lirc devices */
static DEFINE_IDA(lirc_ida);

/* Only used for sysfs but defined to void otherwise */
static struct class *lirc_class;

/**
 * ir_lirc_raw_event() - Send raw IR data to lirc to be relayed to userspace
 *
 * @dev:	the struct rc_dev descriptor of the device
 * @ev:		the struct ir_raw_event descriptor of the pulse/space
 */
void ir_lirc_raw_event(struct rc_dev *dev, struct ir_raw_event ev)
{
	unsigned long flags;
	struct lirc_fh *fh;
	int sample;

	/* Packet start */
	if (ev.reset) {
		/*
		 * Userspace expects a long space event before the start of
		 * the signal to use as a sync.  This may be done with repeat
		 * packets and normal samples.  But if a reset has been sent
		 * then we assume that a long time has passed, so we send a
		 * space with the maximum time value.
		 */
		sample = LIRC_SPACE(LIRC_VALUE_MASK);
		IR_dprintk(2, "delivering reset sync space to lirc_dev\n");

	/* Carrier reports */
	} else if (ev.carrier_report) {
		sample = LIRC_FREQUENCY(ev.carrier);
		IR_dprintk(2, "carrier report (freq: %d)\n", sample);

	/* Packet end */
	} else if (ev.timeout) {
		if (dev->gap)
			return;

		dev->gap_start = ktime_get();
		dev->gap = true;
		dev->gap_duration = ev.duration;

		sample = LIRC_TIMEOUT(ev.duration / 1000);
		IR_dprintk(2, "timeout report (duration: %d)\n", sample);

	/* Normal sample */
	} else {
		if (dev->gap) {
			dev->gap_duration += ktime_to_ns(ktime_sub(ktime_get(),
							 dev->gap_start));

			/* Convert to ms and cap by LIRC_VALUE_MASK */
			do_div(dev->gap_duration, 1000);
			dev->gap_duration = min_t(u64, dev->gap_duration,
						  LIRC_VALUE_MASK);

			spin_lock_irqsave(&dev->lirc_fh_lock, flags);
			list_for_each_entry(fh, &dev->lirc_fh, list)
				kfifo_put(&fh->rawir,
					  LIRC_SPACE(dev->gap_duration));
			spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
			dev->gap = false;
		}

		sample = ev.pulse ? LIRC_PULSE(ev.duration / 1000) :
					LIRC_SPACE(ev.duration / 1000);
		IR_dprintk(2, "delivering %uus %s to lirc_dev\n",
			   TO_US(ev.duration), TO_STR(ev.pulse));
	}

	spin_lock_irqsave(&dev->lirc_fh_lock, flags);
	list_for_each_entry(fh, &dev->lirc_fh, list) {
		if (LIRC_IS_TIMEOUT(sample) && !fh->send_timeout_reports)
			continue;
		if (kfifo_put(&fh->rawir, sample))
			wake_up_poll(&fh->wait_poll, EPOLLIN | EPOLLRDNORM);
	}
	spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
}

/**
 * ir_lirc_scancode_event() - Send scancode data to lirc to be relayed to
 *		userspace. This can be called in atomic context.
 * @dev:	the struct rc_dev descriptor of the device
 * @lsc:	the struct lirc_scancode describing the decoded scancode
 */
void ir_lirc_scancode_event(struct rc_dev *dev, struct lirc_scancode *lsc)
{
	unsigned long flags;
	struct lirc_fh *fh;

	lsc->timestamp = ktime_get_ns();

	spin_lock_irqsave(&dev->lirc_fh_lock, flags);
	list_for_each_entry(fh, &dev->lirc_fh, list) {
		if (kfifo_put(&fh->scancodes, *lsc))
			wake_up_poll(&fh->wait_poll, EPOLLIN | EPOLLRDNORM);
	}
	spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
}
EXPORT_SYMBOL_GPL(ir_lirc_scancode_event);

static int ir_lirc_open(struct inode *inode, struct file *file)
{
	struct rc_dev *dev = container_of(inode->i_cdev, struct rc_dev,
					  lirc_cdev);
	struct lirc_fh *fh = kzalloc(sizeof(*fh), GFP_KERNEL);
	unsigned long flags;
	int retval;

	if (!fh)
		return -ENOMEM;

	get_device(&dev->dev);

	if (!dev->registered) {
		retval = -ENODEV;
		goto out_fh;
	}

	if (dev->driver_type == RC_DRIVER_IR_RAW) {
		if (kfifo_alloc(&fh->rawir, MAX_IR_EVENT_SIZE, GFP_KERNEL)) {
			retval = -ENOMEM;
			goto out_fh;
		}
	}

	if (dev->driver_type != RC_DRIVER_IR_RAW_TX) {
		if (kfifo_alloc(&fh->scancodes, 32, GFP_KERNEL)) {
			retval = -ENOMEM;
			goto out_rawir;
		}
	}

	fh->send_mode = LIRC_MODE_PULSE;
	fh->rc = dev;
	fh->send_timeout_reports = true;

	if (dev->driver_type == RC_DRIVER_SCANCODE)
		fh->rec_mode = LIRC_MODE_SCANCODE;
	else
		fh->rec_mode = LIRC_MODE_MODE2;

	retval = rc_open(dev);
	if (retval)
		goto out_kfifo;

	init_waitqueue_head(&fh->wait_poll);

	file->private_data = fh;
	spin_lock_irqsave(&dev->lirc_fh_lock, flags);
	list_add(&fh->list, &dev->lirc_fh);
	spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);

	nonseekable_open(inode, file);

	return 0;
out_kfifo:
	if (dev->driver_type != RC_DRIVER_IR_RAW_TX)
		kfifo_free(&fh->scancodes);
out_rawir:
	if (dev->driver_type == RC_DRIVER_IR_RAW)
		kfifo_free(&fh->rawir);
out_fh:
	kfree(fh);
	put_device(&dev->dev);

	return retval;
}

static int ir_lirc_close(struct inode *inode, struct file *file)
{
	struct lirc_fh *fh = file->private_data;
	struct rc_dev *dev = fh->rc;
	unsigned long flags;

	spin_lock_irqsave(&dev->lirc_fh_lock, flags);
	list_del(&fh->list);
	spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);

	if (dev->driver_type == RC_DRIVER_IR_RAW)
		kfifo_free(&fh->rawir);
	if (dev->driver_type != RC_DRIVER_IR_RAW_TX)
		kfifo_free(&fh->scancodes);
	kfree(fh);

	rc_close(dev);
	put_device(&dev->dev);

	return 0;
}

static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
				   size_t n, loff_t *ppos)
{
	struct lirc_fh *fh = file->private_data;
	struct rc_dev *dev = fh->rc;
	unsigned int *txbuf;
	struct ir_raw_event *raw = NULL;
	ssize_t ret;
	size_t count;
	ktime_t start;
	s64 towait;
	unsigned int duration = 0; /* signal duration in us */
	int i;

	ret = mutex_lock_interruptible(&dev->lock);
	if (ret)
		return ret;

	if (!dev->registered) {
		ret = -ENODEV;
		goto out_unlock;
	}

	start = ktime_get();

	if (!dev->tx_ir) {
		ret = -EINVAL;
		goto out_unlock;
	}

	if (fh->send_mode == LIRC_MODE_SCANCODE) {
		struct lirc_scancode scan;

		if (n != sizeof(scan)) {
			ret = -EINVAL;
			goto out_unlock;
		}

		if (copy_from_user(&scan, buf, sizeof(scan))) {
			ret = -EFAULT;
			goto out_unlock;
		}

		if (scan.flags || scan.keycode || scan.timestamp) {
			ret = -EINVAL;
			goto out_unlock;
		}

		/*
		 * The scancode field in lirc_scancode is 64-bit simply
		 * to future-proof it, since there are IR protocols encode
		 * use more than 32 bits. For now only 32-bit protocols
		 * are supported.
		 */
		if (scan.scancode > U32_MAX ||
		    !rc_validate_scancode(scan.rc_proto, scan.scancode)) {
			ret = -EINVAL;
			goto out_unlock;
		}

		raw = kmalloc_array(LIRCBUF_SIZE, sizeof(*raw), GFP_KERNEL);
		if (!raw) {
			ret = -ENOMEM;
			goto out_unlock;
		}

		ret = ir_raw_encode_scancode(scan.rc_proto, scan.scancode,
					     raw, LIRCBUF_SIZE);
		if (ret < 0)
			goto out_kfree_raw;

		count = ret;

		txbuf = kmalloc_array(count, sizeof(unsigned int), GFP_KERNEL);
		if (!txbuf) {
			ret = -ENOMEM;
			goto out_kfree_raw;
		}

		for (i = 0; i < count; i++)
			/* Convert from NS to US */
			txbuf[i] = DIV_ROUND_UP(raw[i].duration, 1000);

		if (dev->s_tx_carrier) {
			int carrier = ir_raw_encode_carrier(scan.rc_proto);

			if (carrier > 0)
				dev->s_tx_carrier(dev, carrier);
		}
	} else {
		if (n < sizeof(unsigned int) || n % sizeof(unsigned int)) {
			ret = -EINVAL;
			goto out_unlock;
		}

		count = n / sizeof(unsigned int);
		if (count > LIRCBUF_SIZE || count % 2 == 0) {
			ret = -EINVAL;
			goto out_unlock;
		}

		txbuf = memdup_user(buf, n);
		if (IS_ERR(txbuf)) {
			ret = PTR_ERR(txbuf);
			goto out_unlock;
		}
	}

	for (i = 0; i < count; i++) {
		if (txbuf[i] > IR_MAX_DURATION / 1000 - duration || !txbuf[i]) {
			ret = -EINVAL;
			goto out_kfree;
		}

		duration += txbuf[i];
	}

	ret = dev->tx_ir(dev, txbuf, count);
	if (ret < 0)
		goto out_kfree;

	kfree(txbuf);
	kfree(raw);
	mutex_unlock(&dev->lock);

	/*
	 * The lircd gap calculation expects the write function to
	 * wait for the actual IR signal to be transmitted before
	 * returning.
	 */
	towait = ktime_us_delta(ktime_add_us(start, duration),
				ktime_get());
	if (towait > 0) {
		set_current_state(TASK_INTERRUPTIBLE);
		schedule_timeout(usecs_to_jiffies(towait));
	}

	return n;
out_kfree:
	kfree(txbuf);
out_kfree_raw:
	kfree(raw);
out_unlock:
	mutex_unlock(&dev->lock);
	return ret;
}

static long ir_lirc_ioctl(struct file *file, unsigned int cmd,
			  unsigned long arg)
{
	struct lirc_fh *fh = file->private_data;
	struct rc_dev *dev = fh->rc;
	u32 __user *argp = (u32 __user *)(arg);
	u32 val = 0;
	int ret;

	if (_IOC_DIR(cmd) & _IOC_WRITE) {
		ret = get_user(val, argp);
		if (ret)
			return ret;
	}

	ret = mutex_lock_interruptible(&dev->lock);
	if (ret)
		return ret;

	if (!dev->registered) {
		ret = -ENODEV;
		goto out;
	}

	switch (cmd) {
	case LIRC_GET_FEATURES:
		if (dev->driver_type == RC_DRIVER_SCANCODE)
			val |= LIRC_CAN_REC_SCANCODE;

		if (dev->driver_type == RC_DRIVER_IR_RAW) {
			val |= LIRC_CAN_REC_MODE2;
			if (dev->rx_resolution)
				val |= LIRC_CAN_GET_REC_RESOLUTION;
		}

		if (dev->tx_ir) {
			val |= LIRC_CAN_SEND_PULSE;
			if (dev->s_tx_mask)
				val |= LIRC_CAN_SET_TRANSMITTER_MASK;
			if (dev->s_tx_carrier)
				val |= LIRC_CAN_SET_SEND_CARRIER;
			if (dev->s_tx_duty_cycle)
				val |= LIRC_CAN_SET_SEND_DUTY_CYCLE;
		}

		if (dev->s_rx_carrier_range)
			val |= LIRC_CAN_SET_REC_CARRIER |
				LIRC_CAN_SET_REC_CARRIER_RANGE;

		if (dev->s_learning_mode)
			val |= LIRC_CAN_USE_WIDEBAND_RECEIVER;

		if (dev->s_carrier_report)
			val |= LIRC_CAN_MEASURE_CARRIER;

		if (dev->max_timeout)
			val |= LIRC_CAN_SET_REC_TIMEOUT;

		break;

	/* mode support */
	case LIRC_GET_REC_MODE:
		if (dev->driver_type == RC_DRIVER_IR_RAW_TX)
			ret = -ENOTTY;
		else
			val = fh->rec_mode;
		break;

	case LIRC_SET_REC_MODE:
		switch (dev->driver_type) {
		case RC_DRIVER_IR_RAW_TX:
			ret = -ENOTTY;
			break;
		case RC_DRIVER_SCANCODE:
			if (val != LIRC_MODE_SCANCODE)
				ret = -EINVAL;
			break;
		case RC_DRIVER_IR_RAW:
			if (!(val == LIRC_MODE_MODE2 ||
			      val == LIRC_MODE_SCANCODE))
				ret = -EINVAL;
			break;
		}

		if (!ret)
			fh->rec_mode = val;
		break;

	case LIRC_GET_SEND_MODE:
		if (!dev->tx_ir)
			ret = -ENOTTY;
		else
			val = fh->send_mode;
		break;

	case LIRC_SET_SEND_MODE:
		if (!dev->tx_ir)
			ret = -ENOTTY;
		else if (!(val == LIRC_MODE_PULSE || val == LIRC_MODE_SCANCODE))
			ret = -EINVAL;
		else
			fh->send_mode = val;
		break;

	/* TX settings */
	case LIRC_SET_TRANSMITTER_MASK:
		if (!dev->s_tx_mask)
			ret = -ENOTTY;
		else
			ret = dev->s_tx_mask(dev, val);
		break;

	case LIRC_SET_SEND_CARRIER:
		if (!dev->s_tx_carrier)
			ret = -ENOTTY;
		else
			ret = dev->s_tx_carrier(dev, val);
		break;

	case LIRC_SET_SEND_DUTY_CYCLE:
		if (!dev->s_tx_duty_cycle)
			ret = -ENOTTY;
		else if (val <= 0 || val >= 100)
			ret = -EINVAL;
		else
			ret = dev->s_tx_duty_cycle(dev, val);
		break;

	/* RX settings */
	case LIRC_SET_REC_CARRIER:
		if (!dev->s_rx_carrier_range)
			ret = -ENOTTY;
		else if (val <= 0)
			ret = -EINVAL;
		else
			ret = dev->s_rx_carrier_range(dev, fh->carrier_low,
						      val);
		break;

	case LIRC_SET_REC_CARRIER_RANGE:
		if (!dev->s_rx_carrier_range)
			ret = -ENOTTY;
		else if (val <= 0)
			ret = -EINVAL;
		else
			fh->carrier_low = val;
		break;

	case LIRC_GET_REC_RESOLUTION:
		if (!dev->rx_resolution)
			ret = -ENOTTY;
		else
			val = dev->rx_resolution / 1000;
		break;

	case LIRC_SET_WIDEBAND_RECEIVER:
		if (!dev->s_learning_mode)
			ret = -ENOTTY;
		else
			ret = dev->s_learning_mode(dev, !!val);
		break;

	case LIRC_SET_MEASURE_CARRIER_MODE:
		if (!dev->s_carrier_report)
			ret = -ENOTTY;
		else
			ret = dev->s_carrier_report(dev, !!val);
		break;

	/* Generic timeout support */
	case LIRC_GET_MIN_TIMEOUT:
		if (!dev->max_timeout)
			ret = -ENOTTY;
		else
			val = DIV_ROUND_UP(dev->min_timeout, 1000);
		break;

	case LIRC_GET_MAX_TIMEOUT:
		if (!dev->max_timeout)
			ret = -ENOTTY;
		else
			val = dev->max_timeout / 1000;
		break;

	case LIRC_SET_REC_TIMEOUT:
		if (!dev->max_timeout) {
			ret = -ENOTTY;
		} else if (val > U32_MAX / 1000) {
			/* Check for multiply overflow */
			ret = -EINVAL;
		} else {
			u32 tmp = val * 1000;

			if (tmp < dev->min_timeout || tmp > dev->max_timeout)
				ret = -EINVAL;
			else if (dev->s_timeout)
				ret = dev->s_timeout(dev, tmp);
			else if (!ret)
				dev->timeout = tmp;
		}
		break;

	case LIRC_SET_REC_TIMEOUT_REPORTS:
		if (!dev->timeout)
			ret = -ENOTTY;
		else
			fh->send_timeout_reports = !!val;
		break;

	default:
		ret = -ENOTTY;
	}

	if (!ret && _IOC_DIR(cmd) & _IOC_READ)
		ret = put_user(val, argp);

out:
	mutex_unlock(&dev->lock);
	return ret;
}

static __poll_t ir_lirc_poll(struct file *file, struct poll_table_struct *wait)
{
	struct lirc_fh *fh = file->private_data;
	struct rc_dev *rcdev = fh->rc;
	__poll_t events = 0;

	poll_wait(file, &fh->wait_poll, wait);

	if (!rcdev->registered) {
		events = EPOLLHUP | EPOLLERR;
	} else if (rcdev->driver_type != RC_DRIVER_IR_RAW_TX) {
		if (fh->rec_mode == LIRC_MODE_SCANCODE &&
		    !kfifo_is_empty(&fh->scancodes))
			events = EPOLLIN | EPOLLRDNORM;

		if (fh->rec_mode == LIRC_MODE_MODE2 &&
		    !kfifo_is_empty(&fh->rawir))
			events = EPOLLIN | EPOLLRDNORM;
	}

	return events;
}

static ssize_t ir_lirc_read_mode2(struct file *file, char __user *buffer,
				  size_t length)
{
	struct lirc_fh *fh = file->private_data;
	struct rc_dev *rcdev = fh->rc;
	unsigned int copied;
	int ret;

	if (length < sizeof(unsigned int) || length % sizeof(unsigned int))
		return -EINVAL;

	do {
		if (kfifo_is_empty(&fh->rawir)) {
			if (file->f_flags & O_NONBLOCK)
				return -EAGAIN;

			ret = wait_event_interruptible(fh->wait_poll,
					!kfifo_is_empty(&fh->rawir) ||
					!rcdev->registered);
			if (ret)
				return ret;
		}

		if (!rcdev->registered)
			return -ENODEV;

		ret = mutex_lock_interruptible(&rcdev->lock);
		if (ret)
			return ret;
		ret = kfifo_to_user(&fh->rawir, buffer, length, &copied);
		mutex_unlock(&rcdev->lock);
		if (ret)
			return ret;
	} while (copied == 0);

	return copied;
}

static ssize_t ir_lirc_read_scancode(struct file *file, char __user *buffer,
				     size_t length)
{
	struct lirc_fh *fh = file->private_data;
	struct rc_dev *rcdev = fh->rc;
	unsigned int copied;
	int ret;

	if (length < sizeof(struct lirc_scancode) ||
	    length % sizeof(struct lirc_scancode))
		return -EINVAL;

	do {
		if (kfifo_is_empty(&fh->scancodes)) {
			if (file->f_flags & O_NONBLOCK)
				return -EAGAIN;

			ret = wait_event_interruptible(fh->wait_poll,
					!kfifo_is_empty(&fh->scancodes) ||
					!rcdev->registered);
			if (ret)
				return ret;
		}

		if (!rcdev->registered)
			return -ENODEV;

		ret = mutex_lock_interruptible(&rcdev->lock);
		if (ret)
			return ret;
		ret = kfifo_to_user(&fh->scancodes, buffer, length, &copied);
		mutex_unlock(&rcdev->lock);
		if (ret)
			return ret;
	} while (copied == 0);

	return copied;
}

static ssize_t ir_lirc_read(struct file *file, char __user *buffer,
			    size_t length, loff_t *ppos)
{
	struct lirc_fh *fh = file->private_data;
	struct rc_dev *rcdev = fh->rc;

	if (rcdev->driver_type == RC_DRIVER_IR_RAW_TX)
		return -EINVAL;

	if (!rcdev->registered)
		return -ENODEV;

	if (fh->rec_mode == LIRC_MODE_MODE2)
		return ir_lirc_read_mode2(file, buffer, length);
	else /* LIRC_MODE_SCANCODE */
		return ir_lirc_read_scancode(file, buffer, length);
}

static const struct file_operations lirc_fops = {
	.owner		= THIS_MODULE,
	.write		= ir_lirc_transmit_ir,
	.unlocked_ioctl	= ir_lirc_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl	= ir_lirc_ioctl,
#endif
	.read		= ir_lirc_read,
	.poll		= ir_lirc_poll,
	.open		= ir_lirc_open,
	.release	= ir_lirc_close,
	.llseek		= no_llseek,
};

static void lirc_release_device(struct device *ld)
{
	struct rc_dev *rcdev = container_of(ld, struct rc_dev, lirc_dev);

	put_device(&rcdev->dev);
}

int ir_lirc_register(struct rc_dev *dev)
{
	int err, minor;

	minor = ida_simple_get(&lirc_ida, 0, RC_DEV_MAX, GFP_KERNEL);
	if (minor < 0)
		return minor;

	device_initialize(&dev->lirc_dev);
	dev->lirc_dev.class = lirc_class;
	dev->lirc_dev.parent = &dev->dev;
	dev->lirc_dev.release = lirc_release_device;
	dev->lirc_dev.devt = MKDEV(MAJOR(lirc_base_dev), minor);
	dev_set_name(&dev->lirc_dev, "lirc%d", minor);

	INIT_LIST_HEAD(&dev->lirc_fh);
	spin_lock_init(&dev->lirc_fh_lock);

	cdev_init(&dev->lirc_cdev, &lirc_fops);

	err = cdev_device_add(&dev->lirc_cdev, &dev->lirc_dev);
	if (err)
		goto out_ida;

	get_device(&dev->dev);

	dev_info(&dev->dev, "lirc_dev: driver %s registered at minor = %d",
		 dev->driver_name, minor);

	return 0;

out_ida:
	ida_simple_remove(&lirc_ida, minor);
	return err;
}

void ir_lirc_unregister(struct rc_dev *dev)
{
	unsigned long flags;
	struct lirc_fh *fh;

	dev_dbg(&dev->dev, "lirc_dev: driver %s unregistered from minor = %d\n",
		dev->driver_name, MINOR(dev->lirc_dev.devt));

	spin_lock_irqsave(&dev->lirc_fh_lock, flags);
	list_for_each_entry(fh, &dev->lirc_fh, list)
		wake_up_poll(&fh->wait_poll, EPOLLHUP | EPOLLERR);
	spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);

	cdev_device_del(&dev->lirc_cdev, &dev->lirc_dev);
	ida_simple_remove(&lirc_ida, MINOR(dev->lirc_dev.devt));
}

int __init lirc_dev_init(void)
{
	int retval;

	lirc_class = class_create(THIS_MODULE, "lirc");
	if (IS_ERR(lirc_class)) {
		pr_err("class_create failed\n");
		return PTR_ERR(lirc_class);
	}

	retval = alloc_chrdev_region(&lirc_base_dev, 0, RC_DEV_MAX,
				     "BaseRemoteCtl");
	if (retval) {
		class_destroy(lirc_class);
		pr_err("alloc_chrdev_region failed\n");
		return retval;
	}

	pr_info("IR Remote Control driver registered, major %d\n",
						MAJOR(lirc_base_dev));

	return 0;
}

void __exit lirc_dev_exit(void)
{
	class_destroy(lirc_class);
	unregister_chrdev_region(lirc_base_dev, RC_DEV_MAX);
}

MODULE_ALIAS("lirc_dev");