xref: /openbmc/linux/drivers/media/rc/lirc_dev.c (revision d5a9588c)
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 		/* drop trailing space */
280 		if (!(ret % 2))
281 			count = ret - 1;
282 		else
283 			count = ret;
284 
285 		txbuf = kmalloc_array(count, sizeof(unsigned int), GFP_KERNEL);
286 		if (!txbuf) {
287 			ret = -ENOMEM;
288 			goto out_kfree_raw;
289 		}
290 
291 		for (i = 0; i < count; i++)
292 			txbuf[i] = raw[i].duration;
293 
294 		if (dev->s_tx_carrier) {
295 			int carrier = ir_raw_encode_carrier(scan.rc_proto);
296 
297 			if (carrier > 0)
298 				dev->s_tx_carrier(dev, carrier);
299 		}
300 	} else {
301 		if (n < sizeof(unsigned int) || n % sizeof(unsigned int)) {
302 			ret = -EINVAL;
303 			goto out_unlock;
304 		}
305 
306 		count = n / sizeof(unsigned int);
307 		if (count > LIRCBUF_SIZE || count % 2 == 0) {
308 			ret = -EINVAL;
309 			goto out_unlock;
310 		}
311 
312 		txbuf = memdup_user(buf, n);
313 		if (IS_ERR(txbuf)) {
314 			ret = PTR_ERR(txbuf);
315 			goto out_unlock;
316 		}
317 	}
318 
319 	for (i = 0; i < count; i++) {
320 		if (txbuf[i] > IR_MAX_DURATION - duration || !txbuf[i]) {
321 			ret = -EINVAL;
322 			goto out_kfree;
323 		}
324 
325 		duration += txbuf[i];
326 	}
327 
328 	start = ktime_get();
329 
330 	ret = dev->tx_ir(dev, txbuf, count);
331 	if (ret < 0)
332 		goto out_kfree;
333 
334 	kfree(txbuf);
335 	kfree(raw);
336 	mutex_unlock(&dev->lock);
337 
338 	/*
339 	 * The lircd gap calculation expects the write function to
340 	 * wait for the actual IR signal to be transmitted before
341 	 * returning.
342 	 */
343 	towait = ktime_us_delta(ktime_add_us(start, duration),
344 				ktime_get());
345 	if (towait > 0) {
346 		set_current_state(TASK_INTERRUPTIBLE);
347 		schedule_timeout(usecs_to_jiffies(towait));
348 	}
349 
350 	return n;
351 out_kfree:
352 	kfree(txbuf);
353 out_kfree_raw:
354 	kfree(raw);
355 out_unlock:
356 	mutex_unlock(&dev->lock);
357 	return ret;
358 }
359 
360 static long lirc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
361 {
362 	struct lirc_fh *fh = file->private_data;
363 	struct rc_dev *dev = fh->rc;
364 	u32 __user *argp = (u32 __user *)(arg);
365 	u32 val = 0;
366 	int ret;
367 
368 	if (_IOC_DIR(cmd) & _IOC_WRITE) {
369 		ret = get_user(val, argp);
370 		if (ret)
371 			return ret;
372 	}
373 
374 	ret = mutex_lock_interruptible(&dev->lock);
375 	if (ret)
376 		return ret;
377 
378 	if (!dev->registered) {
379 		ret = -ENODEV;
380 		goto out;
381 	}
382 
383 	switch (cmd) {
384 	case LIRC_GET_FEATURES:
385 		if (dev->driver_type == RC_DRIVER_SCANCODE)
386 			val |= LIRC_CAN_REC_SCANCODE;
387 
388 		if (dev->driver_type == RC_DRIVER_IR_RAW) {
389 			val |= LIRC_CAN_REC_MODE2;
390 			if (dev->rx_resolution)
391 				val |= LIRC_CAN_GET_REC_RESOLUTION;
392 		}
393 
394 		if (dev->tx_ir) {
395 			val |= LIRC_CAN_SEND_PULSE;
396 			if (dev->s_tx_mask)
397 				val |= LIRC_CAN_SET_TRANSMITTER_MASK;
398 			if (dev->s_tx_carrier)
399 				val |= LIRC_CAN_SET_SEND_CARRIER;
400 			if (dev->s_tx_duty_cycle)
401 				val |= LIRC_CAN_SET_SEND_DUTY_CYCLE;
402 		}
403 
404 		if (dev->s_rx_carrier_range)
405 			val |= LIRC_CAN_SET_REC_CARRIER |
406 				LIRC_CAN_SET_REC_CARRIER_RANGE;
407 
408 		if (dev->s_wideband_receiver)
409 			val |= LIRC_CAN_USE_WIDEBAND_RECEIVER;
410 
411 		if (dev->s_carrier_report)
412 			val |= LIRC_CAN_MEASURE_CARRIER;
413 
414 		if (dev->max_timeout)
415 			val |= LIRC_CAN_SET_REC_TIMEOUT;
416 
417 		break;
418 
419 	/* mode support */
420 	case LIRC_GET_REC_MODE:
421 		if (dev->driver_type == RC_DRIVER_IR_RAW_TX)
422 			ret = -ENOTTY;
423 		else
424 			val = fh->rec_mode;
425 		break;
426 
427 	case LIRC_SET_REC_MODE:
428 		switch (dev->driver_type) {
429 		case RC_DRIVER_IR_RAW_TX:
430 			ret = -ENOTTY;
431 			break;
432 		case RC_DRIVER_SCANCODE:
433 			if (val != LIRC_MODE_SCANCODE)
434 				ret = -EINVAL;
435 			break;
436 		case RC_DRIVER_IR_RAW:
437 			if (!(val == LIRC_MODE_MODE2 ||
438 			      val == LIRC_MODE_SCANCODE))
439 				ret = -EINVAL;
440 			break;
441 		}
442 
443 		if (!ret)
444 			fh->rec_mode = val;
445 		break;
446 
447 	case LIRC_GET_SEND_MODE:
448 		if (!dev->tx_ir)
449 			ret = -ENOTTY;
450 		else
451 			val = fh->send_mode;
452 		break;
453 
454 	case LIRC_SET_SEND_MODE:
455 		if (!dev->tx_ir)
456 			ret = -ENOTTY;
457 		else if (!(val == LIRC_MODE_PULSE || val == LIRC_MODE_SCANCODE))
458 			ret = -EINVAL;
459 		else
460 			fh->send_mode = val;
461 		break;
462 
463 	/* TX settings */
464 	case LIRC_SET_TRANSMITTER_MASK:
465 		if (!dev->s_tx_mask)
466 			ret = -ENOTTY;
467 		else
468 			ret = dev->s_tx_mask(dev, val);
469 		break;
470 
471 	case LIRC_SET_SEND_CARRIER:
472 		if (!dev->s_tx_carrier)
473 			ret = -ENOTTY;
474 		else
475 			ret = dev->s_tx_carrier(dev, val);
476 		break;
477 
478 	case LIRC_SET_SEND_DUTY_CYCLE:
479 		if (!dev->s_tx_duty_cycle)
480 			ret = -ENOTTY;
481 		else if (val <= 0 || val >= 100)
482 			ret = -EINVAL;
483 		else
484 			ret = dev->s_tx_duty_cycle(dev, val);
485 		break;
486 
487 	/* RX settings */
488 	case LIRC_SET_REC_CARRIER:
489 		if (!dev->s_rx_carrier_range)
490 			ret = -ENOTTY;
491 		else if (val <= 0)
492 			ret = -EINVAL;
493 		else
494 			ret = dev->s_rx_carrier_range(dev, fh->carrier_low,
495 						      val);
496 		break;
497 
498 	case LIRC_SET_REC_CARRIER_RANGE:
499 		if (!dev->s_rx_carrier_range)
500 			ret = -ENOTTY;
501 		else if (val <= 0)
502 			ret = -EINVAL;
503 		else
504 			fh->carrier_low = val;
505 		break;
506 
507 	case LIRC_GET_REC_RESOLUTION:
508 		if (!dev->rx_resolution)
509 			ret = -ENOTTY;
510 		else
511 			val = dev->rx_resolution;
512 		break;
513 
514 	case LIRC_SET_WIDEBAND_RECEIVER:
515 		if (!dev->s_wideband_receiver)
516 			ret = -ENOTTY;
517 		else
518 			ret = dev->s_wideband_receiver(dev, !!val);
519 		break;
520 
521 	case LIRC_SET_MEASURE_CARRIER_MODE:
522 		if (!dev->s_carrier_report)
523 			ret = -ENOTTY;
524 		else
525 			ret = dev->s_carrier_report(dev, !!val);
526 		break;
527 
528 	/* Generic timeout support */
529 	case LIRC_GET_MIN_TIMEOUT:
530 		if (!dev->max_timeout)
531 			ret = -ENOTTY;
532 		else
533 			val = dev->min_timeout;
534 		break;
535 
536 	case LIRC_GET_MAX_TIMEOUT:
537 		if (!dev->max_timeout)
538 			ret = -ENOTTY;
539 		else
540 			val = dev->max_timeout;
541 		break;
542 
543 	case LIRC_SET_REC_TIMEOUT:
544 		if (!dev->max_timeout) {
545 			ret = -ENOTTY;
546 		} else {
547 			if (val < dev->min_timeout || val > dev->max_timeout)
548 				ret = -EINVAL;
549 			else if (dev->s_timeout)
550 				ret = dev->s_timeout(dev, val);
551 			else
552 				dev->timeout = val;
553 		}
554 		break;
555 
556 	case LIRC_GET_REC_TIMEOUT:
557 		if (!dev->timeout)
558 			ret = -ENOTTY;
559 		else
560 			val = dev->timeout;
561 		break;
562 
563 	case LIRC_SET_REC_TIMEOUT_REPORTS:
564 		if (dev->driver_type != RC_DRIVER_IR_RAW)
565 			ret = -ENOTTY;
566 		break;
567 
568 	default:
569 		ret = -ENOTTY;
570 	}
571 
572 	if (!ret && _IOC_DIR(cmd) & _IOC_READ)
573 		ret = put_user(val, argp);
574 
575 out:
576 	mutex_unlock(&dev->lock);
577 	return ret;
578 }
579 
580 static __poll_t lirc_poll(struct file *file, struct poll_table_struct *wait)
581 {
582 	struct lirc_fh *fh = file->private_data;
583 	struct rc_dev *rcdev = fh->rc;
584 	__poll_t events = 0;
585 
586 	poll_wait(file, &fh->wait_poll, wait);
587 
588 	if (!rcdev->registered) {
589 		events = EPOLLHUP | EPOLLERR;
590 	} else if (rcdev->driver_type != RC_DRIVER_IR_RAW_TX) {
591 		if (fh->rec_mode == LIRC_MODE_SCANCODE &&
592 		    !kfifo_is_empty(&fh->scancodes))
593 			events = EPOLLIN | EPOLLRDNORM;
594 
595 		if (fh->rec_mode == LIRC_MODE_MODE2 &&
596 		    !kfifo_is_empty(&fh->rawir))
597 			events = EPOLLIN | EPOLLRDNORM;
598 	}
599 
600 	return events;
601 }
602 
603 static ssize_t lirc_read_mode2(struct file *file, char __user *buffer,
604 			       size_t length)
605 {
606 	struct lirc_fh *fh = file->private_data;
607 	struct rc_dev *rcdev = fh->rc;
608 	unsigned int copied;
609 	int ret;
610 
611 	if (length < sizeof(unsigned int) || length % sizeof(unsigned int))
612 		return -EINVAL;
613 
614 	do {
615 		if (kfifo_is_empty(&fh->rawir)) {
616 			if (file->f_flags & O_NONBLOCK)
617 				return -EAGAIN;
618 
619 			ret = wait_event_interruptible(fh->wait_poll,
620 					!kfifo_is_empty(&fh->rawir) ||
621 					!rcdev->registered);
622 			if (ret)
623 				return ret;
624 		}
625 
626 		if (!rcdev->registered)
627 			return -ENODEV;
628 
629 		ret = mutex_lock_interruptible(&rcdev->lock);
630 		if (ret)
631 			return ret;
632 		ret = kfifo_to_user(&fh->rawir, buffer, length, &copied);
633 		mutex_unlock(&rcdev->lock);
634 		if (ret)
635 			return ret;
636 	} while (copied == 0);
637 
638 	return copied;
639 }
640 
641 static ssize_t lirc_read_scancode(struct file *file, char __user *buffer,
642 				  size_t length)
643 {
644 	struct lirc_fh *fh = file->private_data;
645 	struct rc_dev *rcdev = fh->rc;
646 	unsigned int copied;
647 	int ret;
648 
649 	if (length < sizeof(struct lirc_scancode) ||
650 	    length % sizeof(struct lirc_scancode))
651 		return -EINVAL;
652 
653 	do {
654 		if (kfifo_is_empty(&fh->scancodes)) {
655 			if (file->f_flags & O_NONBLOCK)
656 				return -EAGAIN;
657 
658 			ret = wait_event_interruptible(fh->wait_poll,
659 					!kfifo_is_empty(&fh->scancodes) ||
660 					!rcdev->registered);
661 			if (ret)
662 				return ret;
663 		}
664 
665 		if (!rcdev->registered)
666 			return -ENODEV;
667 
668 		ret = mutex_lock_interruptible(&rcdev->lock);
669 		if (ret)
670 			return ret;
671 		ret = kfifo_to_user(&fh->scancodes, buffer, length, &copied);
672 		mutex_unlock(&rcdev->lock);
673 		if (ret)
674 			return ret;
675 	} while (copied == 0);
676 
677 	return copied;
678 }
679 
680 static ssize_t lirc_read(struct file *file, char __user *buffer, size_t length,
681 			 loff_t *ppos)
682 {
683 	struct lirc_fh *fh = file->private_data;
684 	struct rc_dev *rcdev = fh->rc;
685 
686 	if (rcdev->driver_type == RC_DRIVER_IR_RAW_TX)
687 		return -EINVAL;
688 
689 	if (!rcdev->registered)
690 		return -ENODEV;
691 
692 	if (fh->rec_mode == LIRC_MODE_MODE2)
693 		return lirc_read_mode2(file, buffer, length);
694 	else /* LIRC_MODE_SCANCODE */
695 		return lirc_read_scancode(file, buffer, length);
696 }
697 
698 static const struct file_operations lirc_fops = {
699 	.owner		= THIS_MODULE,
700 	.write		= lirc_transmit,
701 	.unlocked_ioctl	= lirc_ioctl,
702 	.compat_ioctl	= compat_ptr_ioctl,
703 	.read		= lirc_read,
704 	.poll		= lirc_poll,
705 	.open		= lirc_open,
706 	.release	= lirc_close,
707 	.llseek		= no_llseek,
708 };
709 
710 static void lirc_release_device(struct device *ld)
711 {
712 	struct rc_dev *rcdev = container_of(ld, struct rc_dev, lirc_dev);
713 
714 	put_device(&rcdev->dev);
715 }
716 
717 int lirc_register(struct rc_dev *dev)
718 {
719 	const char *rx_type, *tx_type;
720 	int err, minor;
721 
722 	minor = ida_alloc_max(&lirc_ida, RC_DEV_MAX - 1, GFP_KERNEL);
723 	if (minor < 0)
724 		return minor;
725 
726 	device_initialize(&dev->lirc_dev);
727 	dev->lirc_dev.class = lirc_class;
728 	dev->lirc_dev.parent = &dev->dev;
729 	dev->lirc_dev.release = lirc_release_device;
730 	dev->lirc_dev.devt = MKDEV(MAJOR(lirc_base_dev), minor);
731 	dev_set_name(&dev->lirc_dev, "lirc%d", minor);
732 
733 	INIT_LIST_HEAD(&dev->lirc_fh);
734 	spin_lock_init(&dev->lirc_fh_lock);
735 
736 	cdev_init(&dev->lirc_cdev, &lirc_fops);
737 
738 	err = cdev_device_add(&dev->lirc_cdev, &dev->lirc_dev);
739 	if (err)
740 		goto out_ida;
741 
742 	get_device(&dev->dev);
743 
744 	switch (dev->driver_type) {
745 	case RC_DRIVER_SCANCODE:
746 		rx_type = "scancode";
747 		break;
748 	case RC_DRIVER_IR_RAW:
749 		rx_type = "raw IR";
750 		break;
751 	default:
752 		rx_type = "no";
753 		break;
754 	}
755 
756 	if (dev->tx_ir)
757 		tx_type = "raw IR";
758 	else
759 		tx_type = "no";
760 
761 	dev_info(&dev->dev, "lirc_dev: driver %s registered at minor = %d, %s receiver, %s transmitter",
762 		 dev->driver_name, minor, rx_type, tx_type);
763 
764 	return 0;
765 
766 out_ida:
767 	ida_free(&lirc_ida, minor);
768 	return err;
769 }
770 
771 void lirc_unregister(struct rc_dev *dev)
772 {
773 	unsigned long flags;
774 	struct lirc_fh *fh;
775 
776 	dev_dbg(&dev->dev, "lirc_dev: driver %s unregistered from minor = %d\n",
777 		dev->driver_name, MINOR(dev->lirc_dev.devt));
778 
779 	spin_lock_irqsave(&dev->lirc_fh_lock, flags);
780 	list_for_each_entry(fh, &dev->lirc_fh, list)
781 		wake_up_poll(&fh->wait_poll, EPOLLHUP | EPOLLERR);
782 	spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
783 
784 	cdev_device_del(&dev->lirc_cdev, &dev->lirc_dev);
785 	ida_free(&lirc_ida, MINOR(dev->lirc_dev.devt));
786 }
787 
788 int __init lirc_dev_init(void)
789 {
790 	int retval;
791 
792 	lirc_class = class_create("lirc");
793 	if (IS_ERR(lirc_class)) {
794 		pr_err("class_create failed\n");
795 		return PTR_ERR(lirc_class);
796 	}
797 
798 	retval = alloc_chrdev_region(&lirc_base_dev, 0, RC_DEV_MAX, "lirc");
799 	if (retval) {
800 		class_destroy(lirc_class);
801 		pr_err("alloc_chrdev_region failed\n");
802 		return retval;
803 	}
804 
805 	pr_debug("IR Remote Control driver registered, major %d\n",
806 		 MAJOR(lirc_base_dev));
807 
808 	return 0;
809 }
810 
811 void __exit lirc_dev_exit(void)
812 {
813 	class_destroy(lirc_class);
814 	unregister_chrdev_region(lirc_base_dev, RC_DEV_MAX);
815 }
816 
817 struct rc_dev *rc_dev_get_from_fd(int fd, bool write)
818 {
819 	struct fd f = fdget(fd);
820 	struct lirc_fh *fh;
821 	struct rc_dev *dev;
822 
823 	if (!f.file)
824 		return ERR_PTR(-EBADF);
825 
826 	if (f.file->f_op != &lirc_fops) {
827 		fdput(f);
828 		return ERR_PTR(-EINVAL);
829 	}
830 
831 	if (write && !(f.file->f_mode & FMODE_WRITE)) {
832 		fdput(f);
833 		return ERR_PTR(-EPERM);
834 	}
835 
836 	fh = f.file->private_data;
837 	dev = fh->rc;
838 
839 	get_device(&dev->dev);
840 	fdput(f);
841 
842 	return dev;
843 }
844 
845 MODULE_ALIAS("lirc_dev");
846