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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  */
lirc_raw_event(struct rc_dev * dev,struct ir_raw_event ev)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 	/* 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);
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_us(ktime_sub(ktime_get(),
77 							 dev->gap_start));
78 
79 			/* Cap by LIRC_VALUE_MASK */
80 			dev->gap_duration = min_t(u64, dev->gap_duration,
81 						  LIRC_VALUE_MASK);
82 
83 			spin_lock_irqsave(&dev->lirc_fh_lock, flags);
84 			list_for_each_entry(fh, &dev->lirc_fh, list)
85 				kfifo_put(&fh->rawir,
86 					  LIRC_SPACE(dev->gap_duration));
87 			spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
88 			dev->gap = false;
89 		}
90 
91 		sample = ev.pulse ? LIRC_PULSE(ev.duration) :
92 					LIRC_SPACE(ev.duration);
93 		dev_dbg(&dev->dev, "delivering %uus %s to lirc_dev\n",
94 			ev.duration, TO_STR(ev.pulse));
95 	}
96 
97 	/*
98 	 * bpf does not care about the gap generated above; that exists
99 	 * for backwards compatibility
100 	 */
101 	lirc_bpf_run(dev, sample);
102 
103 	spin_lock_irqsave(&dev->lirc_fh_lock, flags);
104 	list_for_each_entry(fh, &dev->lirc_fh, list) {
105 		if (LIRC_IS_TIMEOUT(sample) && !fh->send_timeout_reports)
106 			continue;
107 		if (kfifo_put(&fh->rawir, sample))
108 			wake_up_poll(&fh->wait_poll, EPOLLIN | EPOLLRDNORM);
109 	}
110 	spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
111 }
112 
113 /**
114  * lirc_scancode_event() - Send scancode data to lirc to be relayed to
115  *		userspace. This can be called in atomic context.
116  * @dev:	the struct rc_dev descriptor of the device
117  * @lsc:	the struct lirc_scancode describing the decoded scancode
118  */
lirc_scancode_event(struct rc_dev * dev,struct lirc_scancode * lsc)119 void lirc_scancode_event(struct rc_dev *dev, struct lirc_scancode *lsc)
120 {
121 	unsigned long flags;
122 	struct lirc_fh *fh;
123 
124 	lsc->timestamp = ktime_get_ns();
125 
126 	spin_lock_irqsave(&dev->lirc_fh_lock, flags);
127 	list_for_each_entry(fh, &dev->lirc_fh, list) {
128 		if (kfifo_put(&fh->scancodes, *lsc))
129 			wake_up_poll(&fh->wait_poll, EPOLLIN | EPOLLRDNORM);
130 	}
131 	spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
132 }
133 EXPORT_SYMBOL_GPL(lirc_scancode_event);
134 
lirc_open(struct inode * inode,struct file * file)135 static int lirc_open(struct inode *inode, struct file *file)
136 {
137 	struct rc_dev *dev = container_of(inode->i_cdev, struct rc_dev,
138 					  lirc_cdev);
139 	struct lirc_fh *fh = kzalloc(sizeof(*fh), GFP_KERNEL);
140 	unsigned long flags;
141 	int retval;
142 
143 	if (!fh)
144 		return -ENOMEM;
145 
146 	get_device(&dev->dev);
147 
148 	if (!dev->registered) {
149 		retval = -ENODEV;
150 		goto out_fh;
151 	}
152 
153 	if (dev->driver_type == RC_DRIVER_IR_RAW) {
154 		if (kfifo_alloc(&fh->rawir, MAX_IR_EVENT_SIZE, GFP_KERNEL)) {
155 			retval = -ENOMEM;
156 			goto out_fh;
157 		}
158 	}
159 
160 	if (dev->driver_type != RC_DRIVER_IR_RAW_TX) {
161 		if (kfifo_alloc(&fh->scancodes, 32, GFP_KERNEL)) {
162 			retval = -ENOMEM;
163 			goto out_rawir;
164 		}
165 	}
166 
167 	fh->send_mode = LIRC_MODE_PULSE;
168 	fh->rc = dev;
169 	fh->send_timeout_reports = true;
170 
171 	if (dev->driver_type == RC_DRIVER_SCANCODE)
172 		fh->rec_mode = LIRC_MODE_SCANCODE;
173 	else
174 		fh->rec_mode = LIRC_MODE_MODE2;
175 
176 	retval = rc_open(dev);
177 	if (retval)
178 		goto out_kfifo;
179 
180 	init_waitqueue_head(&fh->wait_poll);
181 
182 	file->private_data = fh;
183 	spin_lock_irqsave(&dev->lirc_fh_lock, flags);
184 	list_add(&fh->list, &dev->lirc_fh);
185 	spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
186 
187 	stream_open(inode, file);
188 
189 	return 0;
190 out_kfifo:
191 	if (dev->driver_type != RC_DRIVER_IR_RAW_TX)
192 		kfifo_free(&fh->scancodes);
193 out_rawir:
194 	if (dev->driver_type == RC_DRIVER_IR_RAW)
195 		kfifo_free(&fh->rawir);
196 out_fh:
197 	kfree(fh);
198 	put_device(&dev->dev);
199 
200 	return retval;
201 }
202 
lirc_close(struct inode * inode,struct file * file)203 static int lirc_close(struct inode *inode, struct file *file)
204 {
205 	struct lirc_fh *fh = file->private_data;
206 	struct rc_dev *dev = fh->rc;
207 	unsigned long flags;
208 
209 	spin_lock_irqsave(&dev->lirc_fh_lock, flags);
210 	list_del(&fh->list);
211 	spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
212 
213 	if (dev->driver_type == RC_DRIVER_IR_RAW)
214 		kfifo_free(&fh->rawir);
215 	if (dev->driver_type != RC_DRIVER_IR_RAW_TX)
216 		kfifo_free(&fh->scancodes);
217 	kfree(fh);
218 
219 	rc_close(dev);
220 	put_device(&dev->dev);
221 
222 	return 0;
223 }
224 
lirc_transmit(struct file * file,const char __user * buf,size_t n,loff_t * ppos)225 static ssize_t lirc_transmit(struct file *file, const char __user *buf,
226 			     size_t n, loff_t *ppos)
227 {
228 	struct lirc_fh *fh = file->private_data;
229 	struct rc_dev *dev = fh->rc;
230 	unsigned int *txbuf;
231 	struct ir_raw_event *raw = NULL;
232 	ssize_t ret;
233 	size_t count;
234 	ktime_t start;
235 	s64 towait;
236 	unsigned int duration = 0; /* signal duration in us */
237 	int i;
238 
239 	ret = mutex_lock_interruptible(&dev->lock);
240 	if (ret)
241 		return ret;
242 
243 	if (!dev->registered) {
244 		ret = -ENODEV;
245 		goto out_unlock;
246 	}
247 
248 	if (!dev->tx_ir) {
249 		ret = -EINVAL;
250 		goto out_unlock;
251 	}
252 
253 	if (fh->send_mode == LIRC_MODE_SCANCODE) {
254 		struct lirc_scancode scan;
255 
256 		if (n != sizeof(scan)) {
257 			ret = -EINVAL;
258 			goto out_unlock;
259 		}
260 
261 		if (copy_from_user(&scan, buf, sizeof(scan))) {
262 			ret = -EFAULT;
263 			goto out_unlock;
264 		}
265 
266 		if (scan.flags || scan.keycode || scan.timestamp) {
267 			ret = -EINVAL;
268 			goto out_unlock;
269 		}
270 
271 		/* We only have encoders for 32-bit protocols. */
272 		if (scan.scancode > U32_MAX ||
273 		    !rc_validate_scancode(scan.rc_proto, scan.scancode)) {
274 			ret = -EINVAL;
275 			goto out_unlock;
276 		}
277 
278 		raw = kmalloc_array(LIRCBUF_SIZE, sizeof(*raw), GFP_KERNEL);
279 		if (!raw) {
280 			ret = -ENOMEM;
281 			goto out_unlock;
282 		}
283 
284 		ret = ir_raw_encode_scancode(scan.rc_proto, scan.scancode,
285 					     raw, LIRCBUF_SIZE);
286 		if (ret < 0)
287 			goto out_kfree_raw;
288 
289 		/* drop trailing space */
290 		if (!(ret % 2))
291 			count = ret - 1;
292 		else
293 			count = ret;
294 
295 		txbuf = kmalloc_array(count, sizeof(unsigned int), GFP_KERNEL);
296 		if (!txbuf) {
297 			ret = -ENOMEM;
298 			goto out_kfree_raw;
299 		}
300 
301 		for (i = 0; i < count; i++)
302 			txbuf[i] = raw[i].duration;
303 
304 		if (dev->s_tx_carrier) {
305 			int carrier = ir_raw_encode_carrier(scan.rc_proto);
306 
307 			if (carrier > 0)
308 				dev->s_tx_carrier(dev, carrier);
309 		}
310 	} else {
311 		if (n < sizeof(unsigned int) || n % sizeof(unsigned int)) {
312 			ret = -EINVAL;
313 			goto out_unlock;
314 		}
315 
316 		count = n / sizeof(unsigned int);
317 		if (count > LIRCBUF_SIZE || count % 2 == 0) {
318 			ret = -EINVAL;
319 			goto out_unlock;
320 		}
321 
322 		txbuf = memdup_user(buf, n);
323 		if (IS_ERR(txbuf)) {
324 			ret = PTR_ERR(txbuf);
325 			goto out_unlock;
326 		}
327 	}
328 
329 	for (i = 0; i < count; i++) {
330 		if (txbuf[i] > IR_MAX_DURATION - duration || !txbuf[i]) {
331 			ret = -EINVAL;
332 			goto out_kfree;
333 		}
334 
335 		duration += txbuf[i];
336 	}
337 
338 	start = ktime_get();
339 
340 	ret = dev->tx_ir(dev, txbuf, count);
341 	if (ret < 0)
342 		goto out_kfree;
343 
344 	kfree(txbuf);
345 	kfree(raw);
346 	mutex_unlock(&dev->lock);
347 
348 	/*
349 	 * The lircd gap calculation expects the write function to
350 	 * wait for the actual IR signal to be transmitted before
351 	 * returning.
352 	 */
353 	towait = ktime_us_delta(ktime_add_us(start, duration),
354 				ktime_get());
355 	if (towait > 0) {
356 		set_current_state(TASK_INTERRUPTIBLE);
357 		schedule_timeout(usecs_to_jiffies(towait));
358 	}
359 
360 	return n;
361 out_kfree:
362 	kfree(txbuf);
363 out_kfree_raw:
364 	kfree(raw);
365 out_unlock:
366 	mutex_unlock(&dev->lock);
367 	return ret;
368 }
369 
lirc_ioctl(struct file * file,unsigned int cmd,unsigned long arg)370 static long lirc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
371 {
372 	struct lirc_fh *fh = file->private_data;
373 	struct rc_dev *dev = fh->rc;
374 	u32 __user *argp = (u32 __user *)(arg);
375 	u32 val = 0;
376 	int ret;
377 
378 	if (_IOC_DIR(cmd) & _IOC_WRITE) {
379 		ret = get_user(val, argp);
380 		if (ret)
381 			return ret;
382 	}
383 
384 	ret = mutex_lock_interruptible(&dev->lock);
385 	if (ret)
386 		return ret;
387 
388 	if (!dev->registered) {
389 		ret = -ENODEV;
390 		goto out;
391 	}
392 
393 	switch (cmd) {
394 	case LIRC_GET_FEATURES:
395 		if (dev->driver_type == RC_DRIVER_SCANCODE)
396 			val |= LIRC_CAN_REC_SCANCODE;
397 
398 		if (dev->driver_type == RC_DRIVER_IR_RAW) {
399 			val |= LIRC_CAN_REC_MODE2;
400 			if (dev->rx_resolution)
401 				val |= LIRC_CAN_GET_REC_RESOLUTION;
402 		}
403 
404 		if (dev->tx_ir) {
405 			val |= LIRC_CAN_SEND_PULSE;
406 			if (dev->s_tx_mask)
407 				val |= LIRC_CAN_SET_TRANSMITTER_MASK;
408 			if (dev->s_tx_carrier)
409 				val |= LIRC_CAN_SET_SEND_CARRIER;
410 			if (dev->s_tx_duty_cycle)
411 				val |= LIRC_CAN_SET_SEND_DUTY_CYCLE;
412 		}
413 
414 		if (dev->s_rx_carrier_range)
415 			val |= LIRC_CAN_SET_REC_CARRIER |
416 				LIRC_CAN_SET_REC_CARRIER_RANGE;
417 
418 		if (dev->s_learning_mode)
419 			val |= LIRC_CAN_USE_WIDEBAND_RECEIVER;
420 
421 		if (dev->s_carrier_report)
422 			val |= LIRC_CAN_MEASURE_CARRIER;
423 
424 		if (dev->max_timeout)
425 			val |= LIRC_CAN_SET_REC_TIMEOUT;
426 
427 		break;
428 
429 	/* mode support */
430 	case LIRC_GET_REC_MODE:
431 		if (dev->driver_type == RC_DRIVER_IR_RAW_TX)
432 			ret = -ENOTTY;
433 		else
434 			val = fh->rec_mode;
435 		break;
436 
437 	case LIRC_SET_REC_MODE:
438 		switch (dev->driver_type) {
439 		case RC_DRIVER_IR_RAW_TX:
440 			ret = -ENOTTY;
441 			break;
442 		case RC_DRIVER_SCANCODE:
443 			if (val != LIRC_MODE_SCANCODE)
444 				ret = -EINVAL;
445 			break;
446 		case RC_DRIVER_IR_RAW:
447 			if (!(val == LIRC_MODE_MODE2 ||
448 			      val == LIRC_MODE_SCANCODE))
449 				ret = -EINVAL;
450 			break;
451 		}
452 
453 		if (!ret)
454 			fh->rec_mode = val;
455 		break;
456 
457 	case LIRC_GET_SEND_MODE:
458 		if (!dev->tx_ir)
459 			ret = -ENOTTY;
460 		else
461 			val = fh->send_mode;
462 		break;
463 
464 	case LIRC_SET_SEND_MODE:
465 		if (!dev->tx_ir)
466 			ret = -ENOTTY;
467 		else if (!(val == LIRC_MODE_PULSE || val == LIRC_MODE_SCANCODE))
468 			ret = -EINVAL;
469 		else
470 			fh->send_mode = val;
471 		break;
472 
473 	/* TX settings */
474 	case LIRC_SET_TRANSMITTER_MASK:
475 		if (!dev->s_tx_mask)
476 			ret = -ENOTTY;
477 		else
478 			ret = dev->s_tx_mask(dev, val);
479 		break;
480 
481 	case LIRC_SET_SEND_CARRIER:
482 		if (!dev->s_tx_carrier)
483 			ret = -ENOTTY;
484 		else
485 			ret = dev->s_tx_carrier(dev, val);
486 		break;
487 
488 	case LIRC_SET_SEND_DUTY_CYCLE:
489 		if (!dev->s_tx_duty_cycle)
490 			ret = -ENOTTY;
491 		else if (val <= 0 || val >= 100)
492 			ret = -EINVAL;
493 		else
494 			ret = dev->s_tx_duty_cycle(dev, val);
495 		break;
496 
497 	/* RX settings */
498 	case LIRC_SET_REC_CARRIER:
499 		if (!dev->s_rx_carrier_range)
500 			ret = -ENOTTY;
501 		else if (val <= 0)
502 			ret = -EINVAL;
503 		else
504 			ret = dev->s_rx_carrier_range(dev, fh->carrier_low,
505 						      val);
506 		break;
507 
508 	case LIRC_SET_REC_CARRIER_RANGE:
509 		if (!dev->s_rx_carrier_range)
510 			ret = -ENOTTY;
511 		else if (val <= 0)
512 			ret = -EINVAL;
513 		else
514 			fh->carrier_low = val;
515 		break;
516 
517 	case LIRC_GET_REC_RESOLUTION:
518 		if (!dev->rx_resolution)
519 			ret = -ENOTTY;
520 		else
521 			val = dev->rx_resolution;
522 		break;
523 
524 	case LIRC_SET_WIDEBAND_RECEIVER:
525 		if (!dev->s_learning_mode)
526 			ret = -ENOTTY;
527 		else
528 			ret = dev->s_learning_mode(dev, !!val);
529 		break;
530 
531 	case LIRC_SET_MEASURE_CARRIER_MODE:
532 		if (!dev->s_carrier_report)
533 			ret = -ENOTTY;
534 		else
535 			ret = dev->s_carrier_report(dev, !!val);
536 		break;
537 
538 	/* Generic timeout support */
539 	case LIRC_GET_MIN_TIMEOUT:
540 		if (!dev->max_timeout)
541 			ret = -ENOTTY;
542 		else
543 			val = dev->min_timeout;
544 		break;
545 
546 	case LIRC_GET_MAX_TIMEOUT:
547 		if (!dev->max_timeout)
548 			ret = -ENOTTY;
549 		else
550 			val = dev->max_timeout;
551 		break;
552 
553 	case LIRC_SET_REC_TIMEOUT:
554 		if (!dev->max_timeout) {
555 			ret = -ENOTTY;
556 		} else {
557 			if (val < dev->min_timeout || val > dev->max_timeout)
558 				ret = -EINVAL;
559 			else if (dev->s_timeout)
560 				ret = dev->s_timeout(dev, val);
561 			else
562 				dev->timeout = val;
563 		}
564 		break;
565 
566 	case LIRC_GET_REC_TIMEOUT:
567 		if (!dev->timeout)
568 			ret = -ENOTTY;
569 		else
570 			val = dev->timeout;
571 		break;
572 
573 	case LIRC_SET_REC_TIMEOUT_REPORTS:
574 		if (dev->driver_type != RC_DRIVER_IR_RAW)
575 			ret = -ENOTTY;
576 		else
577 			fh->send_timeout_reports = !!val;
578 		break;
579 
580 	default:
581 		ret = -ENOTTY;
582 	}
583 
584 	if (!ret && _IOC_DIR(cmd) & _IOC_READ)
585 		ret = put_user(val, argp);
586 
587 out:
588 	mutex_unlock(&dev->lock);
589 	return ret;
590 }
591 
lirc_poll(struct file * file,struct poll_table_struct * wait)592 static __poll_t lirc_poll(struct file *file, struct poll_table_struct *wait)
593 {
594 	struct lirc_fh *fh = file->private_data;
595 	struct rc_dev *rcdev = fh->rc;
596 	__poll_t events = 0;
597 
598 	poll_wait(file, &fh->wait_poll, wait);
599 
600 	if (!rcdev->registered) {
601 		events = EPOLLHUP | EPOLLERR;
602 	} else if (rcdev->driver_type != RC_DRIVER_IR_RAW_TX) {
603 		if (fh->rec_mode == LIRC_MODE_SCANCODE &&
604 		    !kfifo_is_empty(&fh->scancodes))
605 			events = EPOLLIN | EPOLLRDNORM;
606 
607 		if (fh->rec_mode == LIRC_MODE_MODE2 &&
608 		    !kfifo_is_empty(&fh->rawir))
609 			events = EPOLLIN | EPOLLRDNORM;
610 	}
611 
612 	return events;
613 }
614 
lirc_read_mode2(struct file * file,char __user * buffer,size_t length)615 static ssize_t lirc_read_mode2(struct file *file, char __user *buffer,
616 			       size_t length)
617 {
618 	struct lirc_fh *fh = file->private_data;
619 	struct rc_dev *rcdev = fh->rc;
620 	unsigned int copied;
621 	int ret;
622 
623 	if (length < sizeof(unsigned int) || length % sizeof(unsigned int))
624 		return -EINVAL;
625 
626 	do {
627 		if (kfifo_is_empty(&fh->rawir)) {
628 			if (file->f_flags & O_NONBLOCK)
629 				return -EAGAIN;
630 
631 			ret = wait_event_interruptible(fh->wait_poll,
632 					!kfifo_is_empty(&fh->rawir) ||
633 					!rcdev->registered);
634 			if (ret)
635 				return ret;
636 		}
637 
638 		if (!rcdev->registered)
639 			return -ENODEV;
640 
641 		ret = mutex_lock_interruptible(&rcdev->lock);
642 		if (ret)
643 			return ret;
644 		ret = kfifo_to_user(&fh->rawir, buffer, length, &copied);
645 		mutex_unlock(&rcdev->lock);
646 		if (ret)
647 			return ret;
648 	} while (copied == 0);
649 
650 	return copied;
651 }
652 
lirc_read_scancode(struct file * file,char __user * buffer,size_t length)653 static ssize_t lirc_read_scancode(struct file *file, char __user *buffer,
654 				  size_t length)
655 {
656 	struct lirc_fh *fh = file->private_data;
657 	struct rc_dev *rcdev = fh->rc;
658 	unsigned int copied;
659 	int ret;
660 
661 	if (length < sizeof(struct lirc_scancode) ||
662 	    length % sizeof(struct lirc_scancode))
663 		return -EINVAL;
664 
665 	do {
666 		if (kfifo_is_empty(&fh->scancodes)) {
667 			if (file->f_flags & O_NONBLOCK)
668 				return -EAGAIN;
669 
670 			ret = wait_event_interruptible(fh->wait_poll,
671 					!kfifo_is_empty(&fh->scancodes) ||
672 					!rcdev->registered);
673 			if (ret)
674 				return ret;
675 		}
676 
677 		if (!rcdev->registered)
678 			return -ENODEV;
679 
680 		ret = mutex_lock_interruptible(&rcdev->lock);
681 		if (ret)
682 			return ret;
683 		ret = kfifo_to_user(&fh->scancodes, buffer, length, &copied);
684 		mutex_unlock(&rcdev->lock);
685 		if (ret)
686 			return ret;
687 	} while (copied == 0);
688 
689 	return copied;
690 }
691 
lirc_read(struct file * file,char __user * buffer,size_t length,loff_t * ppos)692 static ssize_t lirc_read(struct file *file, char __user *buffer, size_t length,
693 			 loff_t *ppos)
694 {
695 	struct lirc_fh *fh = file->private_data;
696 	struct rc_dev *rcdev = fh->rc;
697 
698 	if (rcdev->driver_type == RC_DRIVER_IR_RAW_TX)
699 		return -EINVAL;
700 
701 	if (!rcdev->registered)
702 		return -ENODEV;
703 
704 	if (fh->rec_mode == LIRC_MODE_MODE2)
705 		return lirc_read_mode2(file, buffer, length);
706 	else /* LIRC_MODE_SCANCODE */
707 		return lirc_read_scancode(file, buffer, length);
708 }
709 
710 static const struct file_operations lirc_fops = {
711 	.owner		= THIS_MODULE,
712 	.write		= lirc_transmit,
713 	.unlocked_ioctl	= lirc_ioctl,
714 	.compat_ioctl	= compat_ptr_ioctl,
715 	.read		= lirc_read,
716 	.poll		= lirc_poll,
717 	.open		= lirc_open,
718 	.release	= lirc_close,
719 	.llseek		= no_llseek,
720 };
721 
lirc_release_device(struct device * ld)722 static void lirc_release_device(struct device *ld)
723 {
724 	struct rc_dev *rcdev = container_of(ld, struct rc_dev, lirc_dev);
725 
726 	put_device(&rcdev->dev);
727 }
728 
lirc_register(struct rc_dev * dev)729 int lirc_register(struct rc_dev *dev)
730 {
731 	const char *rx_type, *tx_type;
732 	int err, minor;
733 
734 	minor = ida_simple_get(&lirc_ida, 0, RC_DEV_MAX, GFP_KERNEL);
735 	if (minor < 0)
736 		return minor;
737 
738 	device_initialize(&dev->lirc_dev);
739 	dev->lirc_dev.class = lirc_class;
740 	dev->lirc_dev.parent = &dev->dev;
741 	dev->lirc_dev.release = lirc_release_device;
742 	dev->lirc_dev.devt = MKDEV(MAJOR(lirc_base_dev), minor);
743 	dev_set_name(&dev->lirc_dev, "lirc%d", minor);
744 
745 	INIT_LIST_HEAD(&dev->lirc_fh);
746 	spin_lock_init(&dev->lirc_fh_lock);
747 
748 	cdev_init(&dev->lirc_cdev, &lirc_fops);
749 
750 	err = cdev_device_add(&dev->lirc_cdev, &dev->lirc_dev);
751 	if (err)
752 		goto out_ida;
753 
754 	get_device(&dev->dev);
755 
756 	switch (dev->driver_type) {
757 	case RC_DRIVER_SCANCODE:
758 		rx_type = "scancode";
759 		break;
760 	case RC_DRIVER_IR_RAW:
761 		rx_type = "raw IR";
762 		break;
763 	default:
764 		rx_type = "no";
765 		break;
766 	}
767 
768 	if (dev->tx_ir)
769 		tx_type = "raw IR";
770 	else
771 		tx_type = "no";
772 
773 	dev_info(&dev->dev, "lirc_dev: driver %s registered at minor = %d, %s receiver, %s transmitter",
774 		 dev->driver_name, minor, rx_type, tx_type);
775 
776 	return 0;
777 
778 out_ida:
779 	ida_simple_remove(&lirc_ida, minor);
780 	return err;
781 }
782 
lirc_unregister(struct rc_dev * dev)783 void lirc_unregister(struct rc_dev *dev)
784 {
785 	unsigned long flags;
786 	struct lirc_fh *fh;
787 
788 	dev_dbg(&dev->dev, "lirc_dev: driver %s unregistered from minor = %d\n",
789 		dev->driver_name, MINOR(dev->lirc_dev.devt));
790 
791 	spin_lock_irqsave(&dev->lirc_fh_lock, flags);
792 	list_for_each_entry(fh, &dev->lirc_fh, list)
793 		wake_up_poll(&fh->wait_poll, EPOLLHUP | EPOLLERR);
794 	spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
795 
796 	cdev_device_del(&dev->lirc_cdev, &dev->lirc_dev);
797 	ida_simple_remove(&lirc_ida, MINOR(dev->lirc_dev.devt));
798 }
799 
lirc_dev_init(void)800 int __init lirc_dev_init(void)
801 {
802 	int retval;
803 
804 	lirc_class = class_create(THIS_MODULE, "lirc");
805 	if (IS_ERR(lirc_class)) {
806 		pr_err("class_create failed\n");
807 		return PTR_ERR(lirc_class);
808 	}
809 
810 	retval = alloc_chrdev_region(&lirc_base_dev, 0, RC_DEV_MAX, "lirc");
811 	if (retval) {
812 		class_destroy(lirc_class);
813 		pr_err("alloc_chrdev_region failed\n");
814 		return retval;
815 	}
816 
817 	pr_debug("IR Remote Control driver registered, major %d\n",
818 		 MAJOR(lirc_base_dev));
819 
820 	return 0;
821 }
822 
lirc_dev_exit(void)823 void __exit lirc_dev_exit(void)
824 {
825 	class_destroy(lirc_class);
826 	unregister_chrdev_region(lirc_base_dev, RC_DEV_MAX);
827 }
828 
rc_dev_get_from_fd(int fd,bool write)829 struct rc_dev *rc_dev_get_from_fd(int fd, bool write)
830 {
831 	struct fd f = fdget(fd);
832 	struct lirc_fh *fh;
833 	struct rc_dev *dev;
834 
835 	if (!f.file)
836 		return ERR_PTR(-EBADF);
837 
838 	if (f.file->f_op != &lirc_fops) {
839 		fdput(f);
840 		return ERR_PTR(-EINVAL);
841 	}
842 
843 	if (write && !(f.file->f_mode & FMODE_WRITE))
844 		return ERR_PTR(-EPERM);
845 
846 	fh = f.file->private_data;
847 	dev = fh->rc;
848 
849 	get_device(&dev->dev);
850 	fdput(f);
851 
852 	return dev;
853 }
854 
855 MODULE_ALIAS("lirc_dev");
856