xref: /openbmc/linux/drivers/media/rc/lirc_dev.c (revision 7f6964c5)
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	256
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  * ir_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 ir_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 	/* Packet start */
45 	if (ev.reset) {
46 		/*
47 		 * Userspace expects a long space event before the start of
48 		 * the signal to use as a sync.  This may be done with repeat
49 		 * packets and normal samples.  But if a reset has been sent
50 		 * then we assume that a long time has passed, so we send a
51 		 * space with the maximum time value.
52 		 */
53 		sample = LIRC_SPACE(LIRC_VALUE_MASK);
54 		dev_dbg(&dev->dev, "delivering reset sync space to lirc_dev\n");
55 
56 	/* Carrier reports */
57 	} else if (ev.carrier_report) {
58 		sample = LIRC_FREQUENCY(ev.carrier);
59 		dev_dbg(&dev->dev, "carrier report (freq: %d)\n", sample);
60 
61 	/* Packet end */
62 	} else if (ev.timeout) {
63 		if (dev->gap)
64 			return;
65 
66 		dev->gap_start = ktime_get();
67 		dev->gap = true;
68 		dev->gap_duration = ev.duration;
69 
70 		sample = LIRC_TIMEOUT(ev.duration / 1000);
71 		dev_dbg(&dev->dev, "timeout report (duration: %d)\n", sample);
72 
73 	/* Normal sample */
74 	} else {
75 		if (dev->gap) {
76 			dev->gap_duration += ktime_to_ns(ktime_sub(ktime_get(),
77 							 dev->gap_start));
78 
79 			/* Convert to ms and cap by LIRC_VALUE_MASK */
80 			do_div(dev->gap_duration, 1000);
81 			dev->gap_duration = min_t(u64, dev->gap_duration,
82 						  LIRC_VALUE_MASK);
83 
84 			spin_lock_irqsave(&dev->lirc_fh_lock, flags);
85 			list_for_each_entry(fh, &dev->lirc_fh, list)
86 				kfifo_put(&fh->rawir,
87 					  LIRC_SPACE(dev->gap_duration));
88 			spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
89 			dev->gap = false;
90 		}
91 
92 		sample = ev.pulse ? LIRC_PULSE(ev.duration / 1000) :
93 					LIRC_SPACE(ev.duration / 1000);
94 		dev_dbg(&dev->dev, "delivering %uus %s to lirc_dev\n",
95 			TO_US(ev.duration), TO_STR(ev.pulse));
96 	}
97 
98 	/*
99 	 * bpf does not care about the gap generated above; that exists
100 	 * for backwards compatibility
101 	 */
102 	lirc_bpf_run(dev, sample);
103 
104 	spin_lock_irqsave(&dev->lirc_fh_lock, flags);
105 	list_for_each_entry(fh, &dev->lirc_fh, list) {
106 		if (LIRC_IS_TIMEOUT(sample) && !fh->send_timeout_reports)
107 			continue;
108 		if (kfifo_put(&fh->rawir, sample))
109 			wake_up_poll(&fh->wait_poll, EPOLLIN | EPOLLRDNORM);
110 	}
111 	spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
112 }
113 
114 /**
115  * ir_lirc_scancode_event() - Send scancode data to lirc to be relayed to
116  *		userspace. This can be called in atomic context.
117  * @dev:	the struct rc_dev descriptor of the device
118  * @lsc:	the struct lirc_scancode describing the decoded scancode
119  */
120 void ir_lirc_scancode_event(struct rc_dev *dev, struct lirc_scancode *lsc)
121 {
122 	unsigned long flags;
123 	struct lirc_fh *fh;
124 
125 	lsc->timestamp = ktime_get_ns();
126 
127 	spin_lock_irqsave(&dev->lirc_fh_lock, flags);
128 	list_for_each_entry(fh, &dev->lirc_fh, list) {
129 		if (kfifo_put(&fh->scancodes, *lsc))
130 			wake_up_poll(&fh->wait_poll, EPOLLIN | EPOLLRDNORM);
131 	}
132 	spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
133 }
134 EXPORT_SYMBOL_GPL(ir_lirc_scancode_event);
135 
136 static int ir_lirc_open(struct inode *inode, struct file *file)
137 {
138 	struct rc_dev *dev = container_of(inode->i_cdev, struct rc_dev,
139 					  lirc_cdev);
140 	struct lirc_fh *fh = kzalloc(sizeof(*fh), GFP_KERNEL);
141 	unsigned long flags;
142 	int retval;
143 
144 	if (!fh)
145 		return -ENOMEM;
146 
147 	get_device(&dev->dev);
148 
149 	if (!dev->registered) {
150 		retval = -ENODEV;
151 		goto out_fh;
152 	}
153 
154 	if (dev->driver_type == RC_DRIVER_IR_RAW) {
155 		if (kfifo_alloc(&fh->rawir, MAX_IR_EVENT_SIZE, GFP_KERNEL)) {
156 			retval = -ENOMEM;
157 			goto out_fh;
158 		}
159 	}
160 
161 	if (dev->driver_type != RC_DRIVER_IR_RAW_TX) {
162 		if (kfifo_alloc(&fh->scancodes, 32, GFP_KERNEL)) {
163 			retval = -ENOMEM;
164 			goto out_rawir;
165 		}
166 	}
167 
168 	fh->send_mode = LIRC_MODE_PULSE;
169 	fh->rc = dev;
170 	fh->send_timeout_reports = true;
171 
172 	if (dev->driver_type == RC_DRIVER_SCANCODE)
173 		fh->rec_mode = LIRC_MODE_SCANCODE;
174 	else
175 		fh->rec_mode = LIRC_MODE_MODE2;
176 
177 	retval = rc_open(dev);
178 	if (retval)
179 		goto out_kfifo;
180 
181 	init_waitqueue_head(&fh->wait_poll);
182 
183 	file->private_data = fh;
184 	spin_lock_irqsave(&dev->lirc_fh_lock, flags);
185 	list_add(&fh->list, &dev->lirc_fh);
186 	spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
187 
188 	stream_open(inode, file);
189 
190 	return 0;
191 out_kfifo:
192 	if (dev->driver_type != RC_DRIVER_IR_RAW_TX)
193 		kfifo_free(&fh->scancodes);
194 out_rawir:
195 	if (dev->driver_type == RC_DRIVER_IR_RAW)
196 		kfifo_free(&fh->rawir);
197 out_fh:
198 	kfree(fh);
199 	put_device(&dev->dev);
200 
201 	return retval;
202 }
203 
204 static int ir_lirc_close(struct inode *inode, struct file *file)
205 {
206 	struct lirc_fh *fh = file->private_data;
207 	struct rc_dev *dev = fh->rc;
208 	unsigned long flags;
209 
210 	spin_lock_irqsave(&dev->lirc_fh_lock, flags);
211 	list_del(&fh->list);
212 	spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
213 
214 	if (dev->driver_type == RC_DRIVER_IR_RAW)
215 		kfifo_free(&fh->rawir);
216 	if (dev->driver_type != RC_DRIVER_IR_RAW_TX)
217 		kfifo_free(&fh->scancodes);
218 	kfree(fh);
219 
220 	rc_close(dev);
221 	put_device(&dev->dev);
222 
223 	return 0;
224 }
225 
226 static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
227 				   size_t n, loff_t *ppos)
228 {
229 	struct lirc_fh *fh = file->private_data;
230 	struct rc_dev *dev = fh->rc;
231 	unsigned int *txbuf;
232 	struct ir_raw_event *raw = NULL;
233 	ssize_t ret;
234 	size_t count;
235 	ktime_t start;
236 	s64 towait;
237 	unsigned int duration = 0; /* signal duration in us */
238 	int i;
239 
240 	ret = mutex_lock_interruptible(&dev->lock);
241 	if (ret)
242 		return ret;
243 
244 	if (!dev->registered) {
245 		ret = -ENODEV;
246 		goto out_unlock;
247 	}
248 
249 	if (!dev->tx_ir) {
250 		ret = -EINVAL;
251 		goto out_unlock;
252 	}
253 
254 	if (fh->send_mode == LIRC_MODE_SCANCODE) {
255 		struct lirc_scancode scan;
256 
257 		if (n != sizeof(scan)) {
258 			ret = -EINVAL;
259 			goto out_unlock;
260 		}
261 
262 		if (copy_from_user(&scan, buf, sizeof(scan))) {
263 			ret = -EFAULT;
264 			goto out_unlock;
265 		}
266 
267 		if (scan.flags || scan.keycode || scan.timestamp) {
268 			ret = -EINVAL;
269 			goto out_unlock;
270 		}
271 
272 		/*
273 		 * The scancode field in lirc_scancode is 64-bit simply
274 		 * to future-proof it, since there are IR protocols encode
275 		 * use more than 32 bits. For now only 32-bit protocols
276 		 * are supported.
277 		 */
278 		if (scan.scancode > U32_MAX ||
279 		    !rc_validate_scancode(scan.rc_proto, scan.scancode)) {
280 			ret = -EINVAL;
281 			goto out_unlock;
282 		}
283 
284 		raw = kmalloc_array(LIRCBUF_SIZE, sizeof(*raw), GFP_KERNEL);
285 		if (!raw) {
286 			ret = -ENOMEM;
287 			goto out_unlock;
288 		}
289 
290 		ret = ir_raw_encode_scancode(scan.rc_proto, scan.scancode,
291 					     raw, LIRCBUF_SIZE);
292 		if (ret < 0)
293 			goto out_kfree_raw;
294 
295 		count = ret;
296 
297 		txbuf = kmalloc_array(count, sizeof(unsigned int), GFP_KERNEL);
298 		if (!txbuf) {
299 			ret = -ENOMEM;
300 			goto out_kfree_raw;
301 		}
302 
303 		for (i = 0; i < count; i++)
304 			/* Convert from NS to US */
305 			txbuf[i] = DIV_ROUND_UP(raw[i].duration, 1000);
306 
307 		if (dev->s_tx_carrier) {
308 			int carrier = ir_raw_encode_carrier(scan.rc_proto);
309 
310 			if (carrier > 0)
311 				dev->s_tx_carrier(dev, carrier);
312 		}
313 	} else {
314 		if (n < sizeof(unsigned int) || n % sizeof(unsigned int)) {
315 			ret = -EINVAL;
316 			goto out_unlock;
317 		}
318 
319 		count = n / sizeof(unsigned int);
320 		if (count > LIRCBUF_SIZE || count % 2 == 0) {
321 			ret = -EINVAL;
322 			goto out_unlock;
323 		}
324 
325 		txbuf = memdup_user(buf, n);
326 		if (IS_ERR(txbuf)) {
327 			ret = PTR_ERR(txbuf);
328 			goto out_unlock;
329 		}
330 	}
331 
332 	for (i = 0; i < count; i++) {
333 		if (txbuf[i] > IR_MAX_DURATION / 1000 - duration || !txbuf[i]) {
334 			ret = -EINVAL;
335 			goto out_kfree;
336 		}
337 
338 		duration += txbuf[i];
339 	}
340 
341 	start = ktime_get();
342 
343 	ret = dev->tx_ir(dev, txbuf, count);
344 	if (ret < 0)
345 		goto out_kfree;
346 
347 	kfree(txbuf);
348 	kfree(raw);
349 	mutex_unlock(&dev->lock);
350 
351 	/*
352 	 * The lircd gap calculation expects the write function to
353 	 * wait for the actual IR signal to be transmitted before
354 	 * returning.
355 	 */
356 	towait = ktime_us_delta(ktime_add_us(start, duration),
357 				ktime_get());
358 	if (towait > 0) {
359 		set_current_state(TASK_INTERRUPTIBLE);
360 		schedule_timeout(usecs_to_jiffies(towait));
361 	}
362 
363 	return n;
364 out_kfree:
365 	kfree(txbuf);
366 out_kfree_raw:
367 	kfree(raw);
368 out_unlock:
369 	mutex_unlock(&dev->lock);
370 	return ret;
371 }
372 
373 static long ir_lirc_ioctl(struct file *file, unsigned int cmd,
374 			  unsigned long arg)
375 {
376 	struct lirc_fh *fh = file->private_data;
377 	struct rc_dev *dev = fh->rc;
378 	u32 __user *argp = (u32 __user *)(arg);
379 	u32 val = 0;
380 	int ret;
381 
382 	if (_IOC_DIR(cmd) & _IOC_WRITE) {
383 		ret = get_user(val, argp);
384 		if (ret)
385 			return ret;
386 	}
387 
388 	ret = mutex_lock_interruptible(&dev->lock);
389 	if (ret)
390 		return ret;
391 
392 	if (!dev->registered) {
393 		ret = -ENODEV;
394 		goto out;
395 	}
396 
397 	switch (cmd) {
398 	case LIRC_GET_FEATURES:
399 		if (dev->driver_type == RC_DRIVER_SCANCODE)
400 			val |= LIRC_CAN_REC_SCANCODE;
401 
402 		if (dev->driver_type == RC_DRIVER_IR_RAW) {
403 			val |= LIRC_CAN_REC_MODE2;
404 			if (dev->rx_resolution)
405 				val |= LIRC_CAN_GET_REC_RESOLUTION;
406 		}
407 
408 		if (dev->tx_ir) {
409 			val |= LIRC_CAN_SEND_PULSE;
410 			if (dev->s_tx_mask)
411 				val |= LIRC_CAN_SET_TRANSMITTER_MASK;
412 			if (dev->s_tx_carrier)
413 				val |= LIRC_CAN_SET_SEND_CARRIER;
414 			if (dev->s_tx_duty_cycle)
415 				val |= LIRC_CAN_SET_SEND_DUTY_CYCLE;
416 		}
417 
418 		if (dev->s_rx_carrier_range)
419 			val |= LIRC_CAN_SET_REC_CARRIER |
420 				LIRC_CAN_SET_REC_CARRIER_RANGE;
421 
422 		if (dev->s_learning_mode)
423 			val |= LIRC_CAN_USE_WIDEBAND_RECEIVER;
424 
425 		if (dev->s_carrier_report)
426 			val |= LIRC_CAN_MEASURE_CARRIER;
427 
428 		if (dev->max_timeout)
429 			val |= LIRC_CAN_SET_REC_TIMEOUT;
430 
431 		break;
432 
433 	/* mode support */
434 	case LIRC_GET_REC_MODE:
435 		if (dev->driver_type == RC_DRIVER_IR_RAW_TX)
436 			ret = -ENOTTY;
437 		else
438 			val = fh->rec_mode;
439 		break;
440 
441 	case LIRC_SET_REC_MODE:
442 		switch (dev->driver_type) {
443 		case RC_DRIVER_IR_RAW_TX:
444 			ret = -ENOTTY;
445 			break;
446 		case RC_DRIVER_SCANCODE:
447 			if (val != LIRC_MODE_SCANCODE)
448 				ret = -EINVAL;
449 			break;
450 		case RC_DRIVER_IR_RAW:
451 			if (!(val == LIRC_MODE_MODE2 ||
452 			      val == LIRC_MODE_SCANCODE))
453 				ret = -EINVAL;
454 			break;
455 		}
456 
457 		if (!ret)
458 			fh->rec_mode = val;
459 		break;
460 
461 	case LIRC_GET_SEND_MODE:
462 		if (!dev->tx_ir)
463 			ret = -ENOTTY;
464 		else
465 			val = fh->send_mode;
466 		break;
467 
468 	case LIRC_SET_SEND_MODE:
469 		if (!dev->tx_ir)
470 			ret = -ENOTTY;
471 		else if (!(val == LIRC_MODE_PULSE || val == LIRC_MODE_SCANCODE))
472 			ret = -EINVAL;
473 		else
474 			fh->send_mode = val;
475 		break;
476 
477 	/* TX settings */
478 	case LIRC_SET_TRANSMITTER_MASK:
479 		if (!dev->s_tx_mask)
480 			ret = -ENOTTY;
481 		else
482 			ret = dev->s_tx_mask(dev, val);
483 		break;
484 
485 	case LIRC_SET_SEND_CARRIER:
486 		if (!dev->s_tx_carrier)
487 			ret = -ENOTTY;
488 		else
489 			ret = dev->s_tx_carrier(dev, val);
490 		break;
491 
492 	case LIRC_SET_SEND_DUTY_CYCLE:
493 		if (!dev->s_tx_duty_cycle)
494 			ret = -ENOTTY;
495 		else if (val <= 0 || val >= 100)
496 			ret = -EINVAL;
497 		else
498 			ret = dev->s_tx_duty_cycle(dev, val);
499 		break;
500 
501 	/* RX settings */
502 	case LIRC_SET_REC_CARRIER:
503 		if (!dev->s_rx_carrier_range)
504 			ret = -ENOTTY;
505 		else if (val <= 0)
506 			ret = -EINVAL;
507 		else
508 			ret = dev->s_rx_carrier_range(dev, fh->carrier_low,
509 						      val);
510 		break;
511 
512 	case LIRC_SET_REC_CARRIER_RANGE:
513 		if (!dev->s_rx_carrier_range)
514 			ret = -ENOTTY;
515 		else if (val <= 0)
516 			ret = -EINVAL;
517 		else
518 			fh->carrier_low = val;
519 		break;
520 
521 	case LIRC_GET_REC_RESOLUTION:
522 		if (!dev->rx_resolution)
523 			ret = -ENOTTY;
524 		else
525 			val = dev->rx_resolution / 1000;
526 		break;
527 
528 	case LIRC_SET_WIDEBAND_RECEIVER:
529 		if (!dev->s_learning_mode)
530 			ret = -ENOTTY;
531 		else
532 			ret = dev->s_learning_mode(dev, !!val);
533 		break;
534 
535 	case LIRC_SET_MEASURE_CARRIER_MODE:
536 		if (!dev->s_carrier_report)
537 			ret = -ENOTTY;
538 		else
539 			ret = dev->s_carrier_report(dev, !!val);
540 		break;
541 
542 	/* Generic timeout support */
543 	case LIRC_GET_MIN_TIMEOUT:
544 		if (!dev->max_timeout)
545 			ret = -ENOTTY;
546 		else
547 			val = DIV_ROUND_UP(dev->min_timeout, 1000);
548 		break;
549 
550 	case LIRC_GET_MAX_TIMEOUT:
551 		if (!dev->max_timeout)
552 			ret = -ENOTTY;
553 		else
554 			val = dev->max_timeout / 1000;
555 		break;
556 
557 	case LIRC_SET_REC_TIMEOUT:
558 		if (!dev->max_timeout) {
559 			ret = -ENOTTY;
560 		} else if (val > U32_MAX / 1000) {
561 			/* Check for multiply overflow */
562 			ret = -EINVAL;
563 		} else {
564 			u32 tmp = val * 1000;
565 
566 			if (tmp < dev->min_timeout || tmp > dev->max_timeout)
567 				ret = -EINVAL;
568 			else if (dev->s_timeout)
569 				ret = dev->s_timeout(dev, tmp);
570 			else
571 				dev->timeout = tmp;
572 		}
573 		break;
574 
575 	case LIRC_GET_REC_TIMEOUT:
576 		if (!dev->timeout)
577 			ret = -ENOTTY;
578 		else
579 			val = DIV_ROUND_UP(dev->timeout, 1000);
580 		break;
581 
582 	case LIRC_SET_REC_TIMEOUT_REPORTS:
583 		if (dev->driver_type != RC_DRIVER_IR_RAW)
584 			ret = -ENOTTY;
585 		else
586 			fh->send_timeout_reports = !!val;
587 		break;
588 
589 	default:
590 		ret = -ENOTTY;
591 	}
592 
593 	if (!ret && _IOC_DIR(cmd) & _IOC_READ)
594 		ret = put_user(val, argp);
595 
596 out:
597 	mutex_unlock(&dev->lock);
598 	return ret;
599 }
600 
601 static __poll_t ir_lirc_poll(struct file *file, struct poll_table_struct *wait)
602 {
603 	struct lirc_fh *fh = file->private_data;
604 	struct rc_dev *rcdev = fh->rc;
605 	__poll_t events = 0;
606 
607 	poll_wait(file, &fh->wait_poll, wait);
608 
609 	if (!rcdev->registered) {
610 		events = EPOLLHUP | EPOLLERR;
611 	} else if (rcdev->driver_type != RC_DRIVER_IR_RAW_TX) {
612 		if (fh->rec_mode == LIRC_MODE_SCANCODE &&
613 		    !kfifo_is_empty(&fh->scancodes))
614 			events = EPOLLIN | EPOLLRDNORM;
615 
616 		if (fh->rec_mode == LIRC_MODE_MODE2 &&
617 		    !kfifo_is_empty(&fh->rawir))
618 			events = EPOLLIN | EPOLLRDNORM;
619 	}
620 
621 	return events;
622 }
623 
624 static ssize_t ir_lirc_read_mode2(struct file *file, char __user *buffer,
625 				  size_t length)
626 {
627 	struct lirc_fh *fh = file->private_data;
628 	struct rc_dev *rcdev = fh->rc;
629 	unsigned int copied;
630 	int ret;
631 
632 	if (length < sizeof(unsigned int) || length % sizeof(unsigned int))
633 		return -EINVAL;
634 
635 	do {
636 		if (kfifo_is_empty(&fh->rawir)) {
637 			if (file->f_flags & O_NONBLOCK)
638 				return -EAGAIN;
639 
640 			ret = wait_event_interruptible(fh->wait_poll,
641 					!kfifo_is_empty(&fh->rawir) ||
642 					!rcdev->registered);
643 			if (ret)
644 				return ret;
645 		}
646 
647 		if (!rcdev->registered)
648 			return -ENODEV;
649 
650 		ret = mutex_lock_interruptible(&rcdev->lock);
651 		if (ret)
652 			return ret;
653 		ret = kfifo_to_user(&fh->rawir, buffer, length, &copied);
654 		mutex_unlock(&rcdev->lock);
655 		if (ret)
656 			return ret;
657 	} while (copied == 0);
658 
659 	return copied;
660 }
661 
662 static ssize_t ir_lirc_read_scancode(struct file *file, char __user *buffer,
663 				     size_t length)
664 {
665 	struct lirc_fh *fh = file->private_data;
666 	struct rc_dev *rcdev = fh->rc;
667 	unsigned int copied;
668 	int ret;
669 
670 	if (length < sizeof(struct lirc_scancode) ||
671 	    length % sizeof(struct lirc_scancode))
672 		return -EINVAL;
673 
674 	do {
675 		if (kfifo_is_empty(&fh->scancodes)) {
676 			if (file->f_flags & O_NONBLOCK)
677 				return -EAGAIN;
678 
679 			ret = wait_event_interruptible(fh->wait_poll,
680 					!kfifo_is_empty(&fh->scancodes) ||
681 					!rcdev->registered);
682 			if (ret)
683 				return ret;
684 		}
685 
686 		if (!rcdev->registered)
687 			return -ENODEV;
688 
689 		ret = mutex_lock_interruptible(&rcdev->lock);
690 		if (ret)
691 			return ret;
692 		ret = kfifo_to_user(&fh->scancodes, buffer, length, &copied);
693 		mutex_unlock(&rcdev->lock);
694 		if (ret)
695 			return ret;
696 	} while (copied == 0);
697 
698 	return copied;
699 }
700 
701 static ssize_t ir_lirc_read(struct file *file, char __user *buffer,
702 			    size_t length, loff_t *ppos)
703 {
704 	struct lirc_fh *fh = file->private_data;
705 	struct rc_dev *rcdev = fh->rc;
706 
707 	if (rcdev->driver_type == RC_DRIVER_IR_RAW_TX)
708 		return -EINVAL;
709 
710 	if (!rcdev->registered)
711 		return -ENODEV;
712 
713 	if (fh->rec_mode == LIRC_MODE_MODE2)
714 		return ir_lirc_read_mode2(file, buffer, length);
715 	else /* LIRC_MODE_SCANCODE */
716 		return ir_lirc_read_scancode(file, buffer, length);
717 }
718 
719 static const struct file_operations lirc_fops = {
720 	.owner		= THIS_MODULE,
721 	.write		= ir_lirc_transmit_ir,
722 	.unlocked_ioctl	= ir_lirc_ioctl,
723 #ifdef CONFIG_COMPAT
724 	.compat_ioctl	= ir_lirc_ioctl,
725 #endif
726 	.read		= ir_lirc_read,
727 	.poll		= ir_lirc_poll,
728 	.open		= ir_lirc_open,
729 	.release	= ir_lirc_close,
730 	.llseek		= no_llseek,
731 };
732 
733 static void lirc_release_device(struct device *ld)
734 {
735 	struct rc_dev *rcdev = container_of(ld, struct rc_dev, lirc_dev);
736 
737 	put_device(&rcdev->dev);
738 }
739 
740 int ir_lirc_register(struct rc_dev *dev)
741 {
742 	const char *rx_type, *tx_type;
743 	int err, minor;
744 
745 	minor = ida_simple_get(&lirc_ida, 0, RC_DEV_MAX, GFP_KERNEL);
746 	if (minor < 0)
747 		return minor;
748 
749 	device_initialize(&dev->lirc_dev);
750 	dev->lirc_dev.class = lirc_class;
751 	dev->lirc_dev.parent = &dev->dev;
752 	dev->lirc_dev.release = lirc_release_device;
753 	dev->lirc_dev.devt = MKDEV(MAJOR(lirc_base_dev), minor);
754 	dev_set_name(&dev->lirc_dev, "lirc%d", minor);
755 
756 	INIT_LIST_HEAD(&dev->lirc_fh);
757 	spin_lock_init(&dev->lirc_fh_lock);
758 
759 	cdev_init(&dev->lirc_cdev, &lirc_fops);
760 
761 	err = cdev_device_add(&dev->lirc_cdev, &dev->lirc_dev);
762 	if (err)
763 		goto out_ida;
764 
765 	get_device(&dev->dev);
766 
767 	switch (dev->driver_type) {
768 	case RC_DRIVER_SCANCODE:
769 		rx_type = "scancode";
770 		break;
771 	case RC_DRIVER_IR_RAW:
772 		rx_type = "raw IR";
773 		break;
774 	default:
775 		rx_type = "no";
776 		break;
777 	}
778 
779 	if (dev->tx_ir)
780 		tx_type = "raw IR";
781 	else
782 		tx_type = "no";
783 
784 	dev_info(&dev->dev, "lirc_dev: driver %s registered at minor = %d, %s receiver, %s transmitter",
785 		 dev->driver_name, minor, rx_type, tx_type);
786 
787 	return 0;
788 
789 out_ida:
790 	ida_simple_remove(&lirc_ida, minor);
791 	return err;
792 }
793 
794 void ir_lirc_unregister(struct rc_dev *dev)
795 {
796 	unsigned long flags;
797 	struct lirc_fh *fh;
798 
799 	dev_dbg(&dev->dev, "lirc_dev: driver %s unregistered from minor = %d\n",
800 		dev->driver_name, MINOR(dev->lirc_dev.devt));
801 
802 	spin_lock_irqsave(&dev->lirc_fh_lock, flags);
803 	list_for_each_entry(fh, &dev->lirc_fh, list)
804 		wake_up_poll(&fh->wait_poll, EPOLLHUP | EPOLLERR);
805 	spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
806 
807 	cdev_device_del(&dev->lirc_cdev, &dev->lirc_dev);
808 	ida_simple_remove(&lirc_ida, MINOR(dev->lirc_dev.devt));
809 }
810 
811 int __init lirc_dev_init(void)
812 {
813 	int retval;
814 
815 	lirc_class = class_create(THIS_MODULE, "lirc");
816 	if (IS_ERR(lirc_class)) {
817 		pr_err("class_create failed\n");
818 		return PTR_ERR(lirc_class);
819 	}
820 
821 	retval = alloc_chrdev_region(&lirc_base_dev, 0, RC_DEV_MAX,
822 				     "BaseRemoteCtl");
823 	if (retval) {
824 		class_destroy(lirc_class);
825 		pr_err("alloc_chrdev_region failed\n");
826 		return retval;
827 	}
828 
829 	pr_debug("IR Remote Control driver registered, major %d\n",
830 		 MAJOR(lirc_base_dev));
831 
832 	return 0;
833 }
834 
835 void __exit lirc_dev_exit(void)
836 {
837 	class_destroy(lirc_class);
838 	unregister_chrdev_region(lirc_base_dev, RC_DEV_MAX);
839 }
840 
841 struct rc_dev *rc_dev_get_from_fd(int fd)
842 {
843 	struct fd f = fdget(fd);
844 	struct lirc_fh *fh;
845 	struct rc_dev *dev;
846 
847 	if (!f.file)
848 		return ERR_PTR(-EBADF);
849 
850 	if (f.file->f_op != &lirc_fops) {
851 		fdput(f);
852 		return ERR_PTR(-EINVAL);
853 	}
854 
855 	fh = f.file->private_data;
856 	dev = fh->rc;
857 
858 	get_device(&dev->dev);
859 	fdput(f);
860 
861 	return dev;
862 }
863 
864 MODULE_ALIAS("lirc_dev");
865