xref: /openbmc/linux/drivers/media/rc/lirc_dev.c (revision f71a261a)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * LIRC base driver
4  *
5  * by Artur Lipowski <alipowski@interia.pl>
6  */
7 
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 
10 #include <linux/module.h>
11 #include <linux/mutex.h>
12 #include <linux/device.h>
13 #include <linux/file.h>
14 #include <linux/idr.h>
15 #include <linux/poll.h>
16 #include <linux/sched.h>
17 #include <linux/wait.h>
18 
19 #include "rc-core-priv.h"
20 #include <uapi/linux/lirc.h>
21 
22 #define LIRCBUF_SIZE	1024
23 
24 static dev_t lirc_base_dev;
25 
26 /* Used to keep track of allocated lirc devices */
27 static DEFINE_IDA(lirc_ida);
28 
29 /* Only used for sysfs but defined to void otherwise */
30 static struct class *lirc_class;
31 
32 /**
33  * lirc_raw_event() - Send raw IR data to lirc to be relayed to userspace
34  *
35  * @dev:	the struct rc_dev descriptor of the device
36  * @ev:		the struct ir_raw_event descriptor of the pulse/space
37  */
38 void lirc_raw_event(struct rc_dev *dev, struct ir_raw_event ev)
39 {
40 	unsigned long flags;
41 	struct lirc_fh *fh;
42 	int sample;
43 
44 	/* Receiver overflow, data missing */
45 	if (ev.overflow) {
46 		/*
47 		 * Send lirc overflow message. This message is unknown to
48 		 * lircd, but it will interpret this as a long space as
49 		 * long as the value is set to high value. This resets its
50 		 * decoder state.
51 		 */
52 		sample = LIRC_OVERFLOW(LIRC_VALUE_MASK);
53 		dev_dbg(&dev->dev, "delivering overflow to lirc_dev\n");
54 
55 	/* Carrier reports */
56 	} else if (ev.carrier_report) {
57 		sample = LIRC_FREQUENCY(ev.carrier);
58 		dev_dbg(&dev->dev, "carrier report (freq: %d)\n", sample);
59 
60 	/* Packet end */
61 	} else if (ev.timeout) {
62 		dev->gap_start = ktime_get();
63 
64 		sample = LIRC_TIMEOUT(ev.duration);
65 		dev_dbg(&dev->dev, "timeout report (duration: %d)\n", sample);
66 
67 	/* Normal sample */
68 	} else {
69 		if (dev->gap_start) {
70 			u64 duration = ktime_us_delta(ktime_get(),
71 						      dev->gap_start);
72 
73 			/* Cap by LIRC_VALUE_MASK */
74 			duration = min_t(u64, duration, LIRC_VALUE_MASK);
75 
76 			spin_lock_irqsave(&dev->lirc_fh_lock, flags);
77 			list_for_each_entry(fh, &dev->lirc_fh, list)
78 				kfifo_put(&fh->rawir, LIRC_SPACE(duration));
79 			spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
80 			dev->gap_start = 0;
81 		}
82 
83 		sample = ev.pulse ? LIRC_PULSE(ev.duration) :
84 					LIRC_SPACE(ev.duration);
85 		dev_dbg(&dev->dev, "delivering %uus %s to lirc_dev\n",
86 			ev.duration, TO_STR(ev.pulse));
87 	}
88 
89 	/*
90 	 * bpf does not care about the gap generated above; that exists
91 	 * for backwards compatibility
92 	 */
93 	lirc_bpf_run(dev, sample);
94 
95 	spin_lock_irqsave(&dev->lirc_fh_lock, flags);
96 	list_for_each_entry(fh, &dev->lirc_fh, list) {
97 		if (kfifo_put(&fh->rawir, sample))
98 			wake_up_poll(&fh->wait_poll, EPOLLIN | EPOLLRDNORM);
99 	}
100 	spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
101 }
102 
103 /**
104  * lirc_scancode_event() - Send scancode data to lirc to be relayed to
105  *		userspace. This can be called in atomic context.
106  * @dev:	the struct rc_dev descriptor of the device
107  * @lsc:	the struct lirc_scancode describing the decoded scancode
108  */
109 void lirc_scancode_event(struct rc_dev *dev, struct lirc_scancode *lsc)
110 {
111 	unsigned long flags;
112 	struct lirc_fh *fh;
113 
114 	lsc->timestamp = ktime_get_ns();
115 
116 	spin_lock_irqsave(&dev->lirc_fh_lock, flags);
117 	list_for_each_entry(fh, &dev->lirc_fh, list) {
118 		if (kfifo_put(&fh->scancodes, *lsc))
119 			wake_up_poll(&fh->wait_poll, EPOLLIN | EPOLLRDNORM);
120 	}
121 	spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
122 }
123 EXPORT_SYMBOL_GPL(lirc_scancode_event);
124 
125 static int lirc_open(struct inode *inode, struct file *file)
126 {
127 	struct rc_dev *dev = container_of(inode->i_cdev, struct rc_dev,
128 					  lirc_cdev);
129 	struct lirc_fh *fh = kzalloc(sizeof(*fh), GFP_KERNEL);
130 	unsigned long flags;
131 	int retval;
132 
133 	if (!fh)
134 		return -ENOMEM;
135 
136 	get_device(&dev->dev);
137 
138 	if (!dev->registered) {
139 		retval = -ENODEV;
140 		goto out_fh;
141 	}
142 
143 	if (dev->driver_type == RC_DRIVER_IR_RAW) {
144 		if (kfifo_alloc(&fh->rawir, MAX_IR_EVENT_SIZE, GFP_KERNEL)) {
145 			retval = -ENOMEM;
146 			goto out_fh;
147 		}
148 	}
149 
150 	if (dev->driver_type != RC_DRIVER_IR_RAW_TX) {
151 		if (kfifo_alloc(&fh->scancodes, 32, GFP_KERNEL)) {
152 			retval = -ENOMEM;
153 			goto out_rawir;
154 		}
155 	}
156 
157 	fh->send_mode = LIRC_MODE_PULSE;
158 	fh->rc = dev;
159 
160 	if (dev->driver_type == RC_DRIVER_SCANCODE)
161 		fh->rec_mode = LIRC_MODE_SCANCODE;
162 	else
163 		fh->rec_mode = LIRC_MODE_MODE2;
164 
165 	retval = rc_open(dev);
166 	if (retval)
167 		goto out_kfifo;
168 
169 	init_waitqueue_head(&fh->wait_poll);
170 
171 	file->private_data = fh;
172 	spin_lock_irqsave(&dev->lirc_fh_lock, flags);
173 	list_add(&fh->list, &dev->lirc_fh);
174 	spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
175 
176 	stream_open(inode, file);
177 
178 	return 0;
179 out_kfifo:
180 	if (dev->driver_type != RC_DRIVER_IR_RAW_TX)
181 		kfifo_free(&fh->scancodes);
182 out_rawir:
183 	if (dev->driver_type == RC_DRIVER_IR_RAW)
184 		kfifo_free(&fh->rawir);
185 out_fh:
186 	kfree(fh);
187 	put_device(&dev->dev);
188 
189 	return retval;
190 }
191 
192 static int lirc_close(struct inode *inode, struct file *file)
193 {
194 	struct lirc_fh *fh = file->private_data;
195 	struct rc_dev *dev = fh->rc;
196 	unsigned long flags;
197 
198 	spin_lock_irqsave(&dev->lirc_fh_lock, flags);
199 	list_del(&fh->list);
200 	spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
201 
202 	if (dev->driver_type == RC_DRIVER_IR_RAW)
203 		kfifo_free(&fh->rawir);
204 	if (dev->driver_type != RC_DRIVER_IR_RAW_TX)
205 		kfifo_free(&fh->scancodes);
206 	kfree(fh);
207 
208 	rc_close(dev);
209 	put_device(&dev->dev);
210 
211 	return 0;
212 }
213 
214 static ssize_t lirc_transmit(struct file *file, const char __user *buf,
215 			     size_t n, loff_t *ppos)
216 {
217 	struct lirc_fh *fh = file->private_data;
218 	struct rc_dev *dev = fh->rc;
219 	unsigned int *txbuf;
220 	struct ir_raw_event *raw = NULL;
221 	ssize_t ret;
222 	size_t count;
223 	ktime_t start;
224 	s64 towait;
225 	unsigned int duration = 0; /* signal duration in us */
226 	int i;
227 
228 	ret = mutex_lock_interruptible(&dev->lock);
229 	if (ret)
230 		return ret;
231 
232 	if (!dev->registered) {
233 		ret = -ENODEV;
234 		goto out_unlock;
235 	}
236 
237 	if (!dev->tx_ir) {
238 		ret = -EINVAL;
239 		goto out_unlock;
240 	}
241 
242 	if (fh->send_mode == LIRC_MODE_SCANCODE) {
243 		struct lirc_scancode scan;
244 
245 		if (n != sizeof(scan)) {
246 			ret = -EINVAL;
247 			goto out_unlock;
248 		}
249 
250 		if (copy_from_user(&scan, buf, sizeof(scan))) {
251 			ret = -EFAULT;
252 			goto out_unlock;
253 		}
254 
255 		if (scan.flags || scan.keycode || scan.timestamp ||
256 		    scan.rc_proto > RC_PROTO_MAX) {
257 			ret = -EINVAL;
258 			goto out_unlock;
259 		}
260 
261 		/* We only have encoders for 32-bit protocols. */
262 		if (scan.scancode > U32_MAX ||
263 		    !rc_validate_scancode(scan.rc_proto, scan.scancode)) {
264 			ret = -EINVAL;
265 			goto out_unlock;
266 		}
267 
268 		raw = kmalloc_array(LIRCBUF_SIZE, sizeof(*raw), GFP_KERNEL);
269 		if (!raw) {
270 			ret = -ENOMEM;
271 			goto out_unlock;
272 		}
273 
274 		ret = ir_raw_encode_scancode(scan.rc_proto, scan.scancode,
275 					     raw, LIRCBUF_SIZE);
276 		if (ret < 0)
277 			goto out_kfree_raw;
278 
279 		count = ret;
280 
281 		txbuf = kmalloc_array(count, sizeof(unsigned int), GFP_KERNEL);
282 		if (!txbuf) {
283 			ret = -ENOMEM;
284 			goto out_kfree_raw;
285 		}
286 
287 		for (i = 0; i < count; i++)
288 			txbuf[i] = raw[i].duration;
289 
290 		if (dev->s_tx_carrier) {
291 			int carrier = ir_raw_encode_carrier(scan.rc_proto);
292 
293 			if (carrier > 0)
294 				dev->s_tx_carrier(dev, carrier);
295 		}
296 	} else {
297 		if (n < sizeof(unsigned int) || n % sizeof(unsigned int)) {
298 			ret = -EINVAL;
299 			goto out_unlock;
300 		}
301 
302 		count = n / sizeof(unsigned int);
303 		if (count > LIRCBUF_SIZE || count % 2 == 0) {
304 			ret = -EINVAL;
305 			goto out_unlock;
306 		}
307 
308 		txbuf = memdup_user(buf, n);
309 		if (IS_ERR(txbuf)) {
310 			ret = PTR_ERR(txbuf);
311 			goto out_unlock;
312 		}
313 	}
314 
315 	for (i = 0; i < count; i++) {
316 		if (txbuf[i] > IR_MAX_DURATION - duration || !txbuf[i]) {
317 			ret = -EINVAL;
318 			goto out_kfree;
319 		}
320 
321 		duration += txbuf[i];
322 	}
323 
324 	start = ktime_get();
325 
326 	ret = dev->tx_ir(dev, txbuf, count);
327 	if (ret < 0)
328 		goto out_kfree;
329 
330 	kfree(txbuf);
331 	kfree(raw);
332 	mutex_unlock(&dev->lock);
333 
334 	/*
335 	 * The lircd gap calculation expects the write function to
336 	 * wait for the actual IR signal to be transmitted before
337 	 * returning.
338 	 */
339 	towait = ktime_us_delta(ktime_add_us(start, duration),
340 				ktime_get());
341 	if (towait > 0) {
342 		set_current_state(TASK_INTERRUPTIBLE);
343 		schedule_timeout(usecs_to_jiffies(towait));
344 	}
345 
346 	return n;
347 out_kfree:
348 	kfree(txbuf);
349 out_kfree_raw:
350 	kfree(raw);
351 out_unlock:
352 	mutex_unlock(&dev->lock);
353 	return ret;
354 }
355 
356 static long lirc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
357 {
358 	struct lirc_fh *fh = file->private_data;
359 	struct rc_dev *dev = fh->rc;
360 	u32 __user *argp = (u32 __user *)(arg);
361 	u32 val = 0;
362 	int ret;
363 
364 	if (_IOC_DIR(cmd) & _IOC_WRITE) {
365 		ret = get_user(val, argp);
366 		if (ret)
367 			return ret;
368 	}
369 
370 	ret = mutex_lock_interruptible(&dev->lock);
371 	if (ret)
372 		return ret;
373 
374 	if (!dev->registered) {
375 		ret = -ENODEV;
376 		goto out;
377 	}
378 
379 	switch (cmd) {
380 	case LIRC_GET_FEATURES:
381 		if (dev->driver_type == RC_DRIVER_SCANCODE)
382 			val |= LIRC_CAN_REC_SCANCODE;
383 
384 		if (dev->driver_type == RC_DRIVER_IR_RAW) {
385 			val |= LIRC_CAN_REC_MODE2;
386 			if (dev->rx_resolution)
387 				val |= LIRC_CAN_GET_REC_RESOLUTION;
388 		}
389 
390 		if (dev->tx_ir) {
391 			val |= LIRC_CAN_SEND_PULSE;
392 			if (dev->s_tx_mask)
393 				val |= LIRC_CAN_SET_TRANSMITTER_MASK;
394 			if (dev->s_tx_carrier)
395 				val |= LIRC_CAN_SET_SEND_CARRIER;
396 			if (dev->s_tx_duty_cycle)
397 				val |= LIRC_CAN_SET_SEND_DUTY_CYCLE;
398 		}
399 
400 		if (dev->s_rx_carrier_range)
401 			val |= LIRC_CAN_SET_REC_CARRIER |
402 				LIRC_CAN_SET_REC_CARRIER_RANGE;
403 
404 		if (dev->s_wideband_receiver)
405 			val |= LIRC_CAN_USE_WIDEBAND_RECEIVER;
406 
407 		if (dev->s_carrier_report)
408 			val |= LIRC_CAN_MEASURE_CARRIER;
409 
410 		if (dev->max_timeout)
411 			val |= LIRC_CAN_SET_REC_TIMEOUT;
412 
413 		break;
414 
415 	/* mode support */
416 	case LIRC_GET_REC_MODE:
417 		if (dev->driver_type == RC_DRIVER_IR_RAW_TX)
418 			ret = -ENOTTY;
419 		else
420 			val = fh->rec_mode;
421 		break;
422 
423 	case LIRC_SET_REC_MODE:
424 		switch (dev->driver_type) {
425 		case RC_DRIVER_IR_RAW_TX:
426 			ret = -ENOTTY;
427 			break;
428 		case RC_DRIVER_SCANCODE:
429 			if (val != LIRC_MODE_SCANCODE)
430 				ret = -EINVAL;
431 			break;
432 		case RC_DRIVER_IR_RAW:
433 			if (!(val == LIRC_MODE_MODE2 ||
434 			      val == LIRC_MODE_SCANCODE))
435 				ret = -EINVAL;
436 			break;
437 		}
438 
439 		if (!ret)
440 			fh->rec_mode = val;
441 		break;
442 
443 	case LIRC_GET_SEND_MODE:
444 		if (!dev->tx_ir)
445 			ret = -ENOTTY;
446 		else
447 			val = fh->send_mode;
448 		break;
449 
450 	case LIRC_SET_SEND_MODE:
451 		if (!dev->tx_ir)
452 			ret = -ENOTTY;
453 		else if (!(val == LIRC_MODE_PULSE || val == LIRC_MODE_SCANCODE))
454 			ret = -EINVAL;
455 		else
456 			fh->send_mode = val;
457 		break;
458 
459 	/* TX settings */
460 	case LIRC_SET_TRANSMITTER_MASK:
461 		if (!dev->s_tx_mask)
462 			ret = -ENOTTY;
463 		else
464 			ret = dev->s_tx_mask(dev, val);
465 		break;
466 
467 	case LIRC_SET_SEND_CARRIER:
468 		if (!dev->s_tx_carrier)
469 			ret = -ENOTTY;
470 		else
471 			ret = dev->s_tx_carrier(dev, val);
472 		break;
473 
474 	case LIRC_SET_SEND_DUTY_CYCLE:
475 		if (!dev->s_tx_duty_cycle)
476 			ret = -ENOTTY;
477 		else if (val <= 0 || val >= 100)
478 			ret = -EINVAL;
479 		else
480 			ret = dev->s_tx_duty_cycle(dev, val);
481 		break;
482 
483 	/* RX settings */
484 	case LIRC_SET_REC_CARRIER:
485 		if (!dev->s_rx_carrier_range)
486 			ret = -ENOTTY;
487 		else if (val <= 0)
488 			ret = -EINVAL;
489 		else
490 			ret = dev->s_rx_carrier_range(dev, fh->carrier_low,
491 						      val);
492 		break;
493 
494 	case LIRC_SET_REC_CARRIER_RANGE:
495 		if (!dev->s_rx_carrier_range)
496 			ret = -ENOTTY;
497 		else if (val <= 0)
498 			ret = -EINVAL;
499 		else
500 			fh->carrier_low = val;
501 		break;
502 
503 	case LIRC_GET_REC_RESOLUTION:
504 		if (!dev->rx_resolution)
505 			ret = -ENOTTY;
506 		else
507 			val = dev->rx_resolution;
508 		break;
509 
510 	case LIRC_SET_WIDEBAND_RECEIVER:
511 		if (!dev->s_wideband_receiver)
512 			ret = -ENOTTY;
513 		else
514 			ret = dev->s_wideband_receiver(dev, !!val);
515 		break;
516 
517 	case LIRC_SET_MEASURE_CARRIER_MODE:
518 		if (!dev->s_carrier_report)
519 			ret = -ENOTTY;
520 		else
521 			ret = dev->s_carrier_report(dev, !!val);
522 		break;
523 
524 	/* Generic timeout support */
525 	case LIRC_GET_MIN_TIMEOUT:
526 		if (!dev->max_timeout)
527 			ret = -ENOTTY;
528 		else
529 			val = dev->min_timeout;
530 		break;
531 
532 	case LIRC_GET_MAX_TIMEOUT:
533 		if (!dev->max_timeout)
534 			ret = -ENOTTY;
535 		else
536 			val = dev->max_timeout;
537 		break;
538 
539 	case LIRC_SET_REC_TIMEOUT:
540 		if (!dev->max_timeout) {
541 			ret = -ENOTTY;
542 		} else {
543 			if (val < dev->min_timeout || val > dev->max_timeout)
544 				ret = -EINVAL;
545 			else if (dev->s_timeout)
546 				ret = dev->s_timeout(dev, val);
547 			else
548 				dev->timeout = val;
549 		}
550 		break;
551 
552 	case LIRC_GET_REC_TIMEOUT:
553 		if (!dev->timeout)
554 			ret = -ENOTTY;
555 		else
556 			val = dev->timeout;
557 		break;
558 
559 	case LIRC_SET_REC_TIMEOUT_REPORTS:
560 		if (dev->driver_type != RC_DRIVER_IR_RAW)
561 			ret = -ENOTTY;
562 		break;
563 
564 	default:
565 		ret = -ENOTTY;
566 	}
567 
568 	if (!ret && _IOC_DIR(cmd) & _IOC_READ)
569 		ret = put_user(val, argp);
570 
571 out:
572 	mutex_unlock(&dev->lock);
573 	return ret;
574 }
575 
576 static __poll_t lirc_poll(struct file *file, struct poll_table_struct *wait)
577 {
578 	struct lirc_fh *fh = file->private_data;
579 	struct rc_dev *rcdev = fh->rc;
580 	__poll_t events = 0;
581 
582 	poll_wait(file, &fh->wait_poll, wait);
583 
584 	if (!rcdev->registered) {
585 		events = EPOLLHUP | EPOLLERR;
586 	} else if (rcdev->driver_type != RC_DRIVER_IR_RAW_TX) {
587 		if (fh->rec_mode == LIRC_MODE_SCANCODE &&
588 		    !kfifo_is_empty(&fh->scancodes))
589 			events = EPOLLIN | EPOLLRDNORM;
590 
591 		if (fh->rec_mode == LIRC_MODE_MODE2 &&
592 		    !kfifo_is_empty(&fh->rawir))
593 			events = EPOLLIN | EPOLLRDNORM;
594 	}
595 
596 	return events;
597 }
598 
599 static ssize_t lirc_read_mode2(struct file *file, char __user *buffer,
600 			       size_t length)
601 {
602 	struct lirc_fh *fh = file->private_data;
603 	struct rc_dev *rcdev = fh->rc;
604 	unsigned int copied;
605 	int ret;
606 
607 	if (length < sizeof(unsigned int) || length % sizeof(unsigned int))
608 		return -EINVAL;
609 
610 	do {
611 		if (kfifo_is_empty(&fh->rawir)) {
612 			if (file->f_flags & O_NONBLOCK)
613 				return -EAGAIN;
614 
615 			ret = wait_event_interruptible(fh->wait_poll,
616 					!kfifo_is_empty(&fh->rawir) ||
617 					!rcdev->registered);
618 			if (ret)
619 				return ret;
620 		}
621 
622 		if (!rcdev->registered)
623 			return -ENODEV;
624 
625 		ret = mutex_lock_interruptible(&rcdev->lock);
626 		if (ret)
627 			return ret;
628 		ret = kfifo_to_user(&fh->rawir, buffer, length, &copied);
629 		mutex_unlock(&rcdev->lock);
630 		if (ret)
631 			return ret;
632 	} while (copied == 0);
633 
634 	return copied;
635 }
636 
637 static ssize_t lirc_read_scancode(struct file *file, char __user *buffer,
638 				  size_t length)
639 {
640 	struct lirc_fh *fh = file->private_data;
641 	struct rc_dev *rcdev = fh->rc;
642 	unsigned int copied;
643 	int ret;
644 
645 	if (length < sizeof(struct lirc_scancode) ||
646 	    length % sizeof(struct lirc_scancode))
647 		return -EINVAL;
648 
649 	do {
650 		if (kfifo_is_empty(&fh->scancodes)) {
651 			if (file->f_flags & O_NONBLOCK)
652 				return -EAGAIN;
653 
654 			ret = wait_event_interruptible(fh->wait_poll,
655 					!kfifo_is_empty(&fh->scancodes) ||
656 					!rcdev->registered);
657 			if (ret)
658 				return ret;
659 		}
660 
661 		if (!rcdev->registered)
662 			return -ENODEV;
663 
664 		ret = mutex_lock_interruptible(&rcdev->lock);
665 		if (ret)
666 			return ret;
667 		ret = kfifo_to_user(&fh->scancodes, buffer, length, &copied);
668 		mutex_unlock(&rcdev->lock);
669 		if (ret)
670 			return ret;
671 	} while (copied == 0);
672 
673 	return copied;
674 }
675 
676 static ssize_t lirc_read(struct file *file, char __user *buffer, size_t length,
677 			 loff_t *ppos)
678 {
679 	struct lirc_fh *fh = file->private_data;
680 	struct rc_dev *rcdev = fh->rc;
681 
682 	if (rcdev->driver_type == RC_DRIVER_IR_RAW_TX)
683 		return -EINVAL;
684 
685 	if (!rcdev->registered)
686 		return -ENODEV;
687 
688 	if (fh->rec_mode == LIRC_MODE_MODE2)
689 		return lirc_read_mode2(file, buffer, length);
690 	else /* LIRC_MODE_SCANCODE */
691 		return lirc_read_scancode(file, buffer, length);
692 }
693 
694 static const struct file_operations lirc_fops = {
695 	.owner		= THIS_MODULE,
696 	.write		= lirc_transmit,
697 	.unlocked_ioctl	= lirc_ioctl,
698 	.compat_ioctl	= compat_ptr_ioctl,
699 	.read		= lirc_read,
700 	.poll		= lirc_poll,
701 	.open		= lirc_open,
702 	.release	= lirc_close,
703 	.llseek		= no_llseek,
704 };
705 
706 static void lirc_release_device(struct device *ld)
707 {
708 	struct rc_dev *rcdev = container_of(ld, struct rc_dev, lirc_dev);
709 
710 	put_device(&rcdev->dev);
711 }
712 
713 int lirc_register(struct rc_dev *dev)
714 {
715 	const char *rx_type, *tx_type;
716 	int err, minor;
717 
718 	minor = ida_simple_get(&lirc_ida, 0, RC_DEV_MAX, GFP_KERNEL);
719 	if (minor < 0)
720 		return minor;
721 
722 	device_initialize(&dev->lirc_dev);
723 	dev->lirc_dev.class = lirc_class;
724 	dev->lirc_dev.parent = &dev->dev;
725 	dev->lirc_dev.release = lirc_release_device;
726 	dev->lirc_dev.devt = MKDEV(MAJOR(lirc_base_dev), minor);
727 	dev_set_name(&dev->lirc_dev, "lirc%d", minor);
728 
729 	INIT_LIST_HEAD(&dev->lirc_fh);
730 	spin_lock_init(&dev->lirc_fh_lock);
731 
732 	cdev_init(&dev->lirc_cdev, &lirc_fops);
733 
734 	err = cdev_device_add(&dev->lirc_cdev, &dev->lirc_dev);
735 	if (err)
736 		goto out_ida;
737 
738 	get_device(&dev->dev);
739 
740 	switch (dev->driver_type) {
741 	case RC_DRIVER_SCANCODE:
742 		rx_type = "scancode";
743 		break;
744 	case RC_DRIVER_IR_RAW:
745 		rx_type = "raw IR";
746 		break;
747 	default:
748 		rx_type = "no";
749 		break;
750 	}
751 
752 	if (dev->tx_ir)
753 		tx_type = "raw IR";
754 	else
755 		tx_type = "no";
756 
757 	dev_info(&dev->dev, "lirc_dev: driver %s registered at minor = %d, %s receiver, %s transmitter",
758 		 dev->driver_name, minor, rx_type, tx_type);
759 
760 	return 0;
761 
762 out_ida:
763 	ida_simple_remove(&lirc_ida, minor);
764 	return err;
765 }
766 
767 void lirc_unregister(struct rc_dev *dev)
768 {
769 	unsigned long flags;
770 	struct lirc_fh *fh;
771 
772 	dev_dbg(&dev->dev, "lirc_dev: driver %s unregistered from minor = %d\n",
773 		dev->driver_name, MINOR(dev->lirc_dev.devt));
774 
775 	spin_lock_irqsave(&dev->lirc_fh_lock, flags);
776 	list_for_each_entry(fh, &dev->lirc_fh, list)
777 		wake_up_poll(&fh->wait_poll, EPOLLHUP | EPOLLERR);
778 	spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
779 
780 	cdev_device_del(&dev->lirc_cdev, &dev->lirc_dev);
781 	ida_simple_remove(&lirc_ida, MINOR(dev->lirc_dev.devt));
782 }
783 
784 int __init lirc_dev_init(void)
785 {
786 	int retval;
787 
788 	lirc_class = class_create(THIS_MODULE, "lirc");
789 	if (IS_ERR(lirc_class)) {
790 		pr_err("class_create failed\n");
791 		return PTR_ERR(lirc_class);
792 	}
793 
794 	retval = alloc_chrdev_region(&lirc_base_dev, 0, RC_DEV_MAX, "lirc");
795 	if (retval) {
796 		class_destroy(lirc_class);
797 		pr_err("alloc_chrdev_region failed\n");
798 		return retval;
799 	}
800 
801 	pr_debug("IR Remote Control driver registered, major %d\n",
802 		 MAJOR(lirc_base_dev));
803 
804 	return 0;
805 }
806 
807 void __exit lirc_dev_exit(void)
808 {
809 	class_destroy(lirc_class);
810 	unregister_chrdev_region(lirc_base_dev, RC_DEV_MAX);
811 }
812 
813 struct rc_dev *rc_dev_get_from_fd(int fd)
814 {
815 	struct fd f = fdget(fd);
816 	struct lirc_fh *fh;
817 	struct rc_dev *dev;
818 
819 	if (!f.file)
820 		return ERR_PTR(-EBADF);
821 
822 	if (f.file->f_op != &lirc_fops) {
823 		fdput(f);
824 		return ERR_PTR(-EINVAL);
825 	}
826 
827 	fh = f.file->private_data;
828 	dev = fh->rc;
829 
830 	get_device(&dev->dev);
831 	fdput(f);
832 
833 	return dev;
834 }
835 
836 MODULE_ALIAS("lirc_dev");
837