summaryrefslogtreecommitdiff
path: root/drivers/media/rc/lirc_dev.c
blob: 9080e39ea391e9da698abcfdfb5261de476ab271 (plain)
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
/*
 * 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/sched/signal.h>
#include <linux/ioctl.h>
#include <linux/poll.h>
#include <linux/mutex.h>
#include <linux/device.h>
#include <linux/cdev.h>

#include <media/rc-core.h>
#include <media/lirc.h>
#include <media/lirc_dev.h>

#define NOPLUG		-1
#define LOGHEAD		"lirc_dev (%s[%d]): "

static dev_t lirc_base_dev;

struct irctl {
	struct lirc_driver d;
	int attached;
	int open;

	struct mutex irctl_lock;
	struct lirc_buffer *buf;
	bool buf_internal;
	unsigned int chunk_size;

	struct device dev;
	struct cdev cdev;
};

static DEFINE_MUTEX(lirc_dev_lock);

static struct irctl *irctls[MAX_IRCTL_DEVICES];

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

static void lirc_release(struct device *ld)
{
	struct irctl *ir = container_of(ld, struct irctl, dev);

	put_device(ir->dev.parent);

	if (ir->buf_internal) {
		lirc_buffer_free(ir->buf);
		kfree(ir->buf);
	}

	mutex_lock(&lirc_dev_lock);
	irctls[ir->d.minor] = NULL;
	mutex_unlock(&lirc_dev_lock);
	kfree(ir);
}

static int lirc_allocate_buffer(struct irctl *ir)
{
	int err = 0;
	int bytes_in_key;
	unsigned int chunk_size;
	unsigned int buffer_size;
	struct lirc_driver *d = &ir->d;

	bytes_in_key = BITS_TO_LONGS(d->code_length) +
						(d->code_length % 8 ? 1 : 0);
	buffer_size = d->buffer_size ? d->buffer_size : BUFLEN / bytes_in_key;
	chunk_size  = d->chunk_size  ? d->chunk_size  : bytes_in_key;

	if (d->rbuf) {
		ir->buf = d->rbuf;
		ir->buf_internal = false;
	} else {
		ir->buf = kmalloc(sizeof(struct lirc_buffer), GFP_KERNEL);
		if (!ir->buf) {
			err = -ENOMEM;
			goto out;
		}

		err = lirc_buffer_init(ir->buf, chunk_size, buffer_size);
		if (err) {
			kfree(ir->buf);
			ir->buf = NULL;
			goto out;
		}

		ir->buf_internal = true;
		d->rbuf = ir->buf;
	}
	ir->chunk_size = ir->buf->chunk_size;

out:
	return err;
}

int lirc_register_driver(struct lirc_driver *d)
{
	struct irctl *ir;
	int minor;
	int err;

	if (!d) {
		pr_err("driver pointer must be not NULL!\n");
		return -EBADRQC;
	}

	if (!d->dev) {
		pr_err("dev pointer not filled in!\n");
		return -EINVAL;
	}

	if (!d->fops) {
		pr_err("fops pointer not filled in!\n");
		return -EINVAL;
	}

	if (d->minor >= MAX_IRCTL_DEVICES) {
		dev_err(d->dev, "minor must be between 0 and %d!\n",
						MAX_IRCTL_DEVICES - 1);
		return -EBADRQC;
	}

	if (d->code_length < 1 || d->code_length > (BUFLEN * 8)) {
		dev_err(d->dev, "code length must be less than %d bits\n",
								BUFLEN * 8);
		return -EBADRQC;
	}

	if (!d->rbuf && !(d->fops && d->fops->read &&
			  d->fops->poll && d->fops->unlocked_ioctl)) {
		dev_err(d->dev, "undefined read, poll, ioctl\n");
		return -EBADRQC;
	}

	mutex_lock(&lirc_dev_lock);

	minor = d->minor;

	if (minor < 0) {
		/* find first free slot for driver */
		for (minor = 0; minor < MAX_IRCTL_DEVICES; minor++)
			if (!irctls[minor])
				break;
		if (minor == MAX_IRCTL_DEVICES) {
			dev_err(d->dev, "no free slots for drivers!\n");
			err = -ENOMEM;
			goto out_lock;
		}
	} else if (irctls[minor]) {
		dev_err(d->dev, "minor (%d) just registered!\n", minor);
		err = -EBUSY;
		goto out_lock;
	}

	ir = kzalloc(sizeof(struct irctl), GFP_KERNEL);
	if (!ir) {
		err = -ENOMEM;
		goto out_lock;
	}

	mutex_init(&ir->irctl_lock);
	irctls[minor] = ir;
	d->minor = minor;

	/* some safety check 8-) */
	d->name[sizeof(d->name)-1] = '\0';

	if (d->features == 0)
		d->features = LIRC_CAN_REC_LIRCCODE;

	ir->d = *d;

	if (LIRC_CAN_REC(d->features)) {
		err = lirc_allocate_buffer(irctls[minor]);
		if (err) {
			kfree(ir);
			goto out_lock;
		}
		d->rbuf = ir->buf;
	}

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

	cdev_init(&ir->cdev, d->fops);
	ir->cdev.owner = ir->d.owner;
	ir->cdev.kobj.parent = &ir->dev.kobj;

	err = cdev_add(&ir->cdev, ir->dev.devt, 1);
	if (err)
		goto out_free_dev;

	ir->attached = 1;

	err = device_add(&ir->dev);
	if (err)
		goto out_cdev;

	mutex_unlock(&lirc_dev_lock);

	get_device(ir->dev.parent);

	dev_info(ir->d.dev, "lirc_dev: driver %s registered at minor = %d\n",
		 ir->d.name, ir->d.minor);

	return minor;

out_cdev:
	cdev_del(&ir->cdev);
out_free_dev:
	put_device(&ir->dev);
out_lock:
	mutex_unlock(&lirc_dev_lock);

	return err;
}
EXPORT_SYMBOL(lirc_register_driver);

int lirc_unregister_driver(int minor)
{
	struct irctl *ir;

	if (minor < 0 || minor >= MAX_IRCTL_DEVICES) {
		pr_err("minor (%d) must be between 0 and %d!\n",
					minor, MAX_IRCTL_DEVICES - 1);
		return -EBADRQC;
	}

	ir = irctls[minor];
	if (!ir) {
		pr_err("failed to get irctl\n");
		return -ENOENT;
	}

	mutex_lock(&lirc_dev_lock);

	if (ir->d.minor != minor) {
		dev_err(ir->d.dev, "lirc_dev: minor %d device not registered\n",
									minor);
		mutex_unlock(&lirc_dev_lock);
		return -ENOENT;
	}

	dev_dbg(ir->d.dev, "lirc_dev: driver %s unregistered from minor = %d\n",
		ir->d.name, ir->d.minor);

	ir->attached = 0;
	if (ir->open) {
		dev_dbg(ir->d.dev, LOGHEAD "releasing opened driver\n",
			ir->d.name, ir->d.minor);
		wake_up_interruptible(&ir->buf->wait_poll);
	}

	mutex_unlock(&lirc_dev_lock);

	device_del(&ir->dev);
	cdev_del(&ir->cdev);
	put_device(&ir->dev);

	return 0;
}
EXPORT_SYMBOL(lirc_unregister_driver);

int lirc_dev_fop_open(struct inode *inode, struct file *file)
{
	struct irctl *ir;
	int retval = 0;

	if (iminor(inode) >= MAX_IRCTL_DEVICES) {
		pr_err("open result for %d is -ENODEV\n", iminor(inode));
		return -ENODEV;
	}

	if (mutex_lock_interruptible(&lirc_dev_lock))
		return -ERESTARTSYS;

	ir = irctls[iminor(inode)];
	mutex_unlock(&lirc_dev_lock);

	if (!ir) {
		retval = -ENODEV;
		goto error;
	}

	dev_dbg(ir->d.dev, LOGHEAD "open called\n", ir->d.name, ir->d.minor);

	if (ir->d.minor == NOPLUG) {
		retval = -ENODEV;
		goto error;
	}

	if (ir->open) {
		retval = -EBUSY;
		goto error;
	}

	if (ir->d.rdev) {
		retval = rc_open(ir->d.rdev);
		if (retval)
			goto error;
	}

	if (ir->buf)
		lirc_buffer_clear(ir->buf);

	ir->open++;

error:
	nonseekable_open(inode, file);

	return retval;
}
EXPORT_SYMBOL(lirc_dev_fop_open);

int lirc_dev_fop_close(struct inode *inode, struct file *file)
{
	struct irctl *ir = irctls[iminor(inode)];
	int ret;

	if (!ir) {
		pr_err("called with invalid irctl\n");
		return -EINVAL;
	}

	ret = mutex_lock_killable(&lirc_dev_lock);
	WARN_ON(ret);

	rc_close(ir->d.rdev);

	ir->open--;
	if (!ret)
		mutex_unlock(&lirc_dev_lock);

	return 0;
}
EXPORT_SYMBOL(lirc_dev_fop_close);

unsigned int lirc_dev_fop_poll(struct file *file, poll_table *wait)
{
	struct irctl *ir = irctls[iminor(file_inode(file))];
	unsigned int ret;

	if (!ir) {
		pr_err("called with invalid irctl\n");
		return POLLERR;
	}

	if (!ir->attached)
		return POLLHUP | POLLERR;

	if (ir->buf) {
		poll_wait(file, &ir->buf->wait_poll, wait);

		if (lirc_buffer_empty(ir->buf))
			ret = 0;
		else
			ret = POLLIN | POLLRDNORM;
	} else
		ret = POLLERR;

	dev_dbg(ir->d.dev, LOGHEAD "poll result = %d\n",
		ir->d.name, ir->d.minor, ret);

	return ret;
}
EXPORT_SYMBOL(lirc_dev_fop_poll);

long lirc_dev_fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	__u32 mode;
	int result = 0;
	struct irctl *ir = irctls[iminor(file_inode(file))];

	if (!ir) {
		pr_err("no irctl found!\n");
		return -ENODEV;
	}

	dev_dbg(ir->d.dev, LOGHEAD "ioctl called (0x%x)\n",
		ir->d.name, ir->d.minor, cmd);

	if (ir->d.minor == NOPLUG || !ir->attached) {
		dev_err(ir->d.dev, LOGHEAD "ioctl result = -ENODEV\n",
			ir->d.name, ir->d.minor);
		return -ENODEV;
	}

	mutex_lock(&ir->irctl_lock);

	switch (cmd) {
	case LIRC_GET_FEATURES:
		result = put_user(ir->d.features, (__u32 __user *)arg);
		break;
	case LIRC_GET_REC_MODE:
		if (!LIRC_CAN_REC(ir->d.features)) {
			result = -ENOTTY;
			break;
		}

		result = put_user(LIRC_REC2MODE
				  (ir->d.features & LIRC_CAN_REC_MASK),
				  (__u32 __user *)arg);
		break;
	case LIRC_SET_REC_MODE:
		if (!LIRC_CAN_REC(ir->d.features)) {
			result = -ENOTTY;
			break;
		}

		result = get_user(mode, (__u32 __user *)arg);
		if (!result && !(LIRC_MODE2REC(mode) & ir->d.features))
			result = -EINVAL;
		/*
		 * FIXME: We should actually set the mode somehow but
		 * for now, lirc_serial doesn't support mode changing either
		 */
		break;
	case LIRC_GET_LENGTH:
		result = put_user(ir->d.code_length, (__u32 __user *)arg);
		break;
	case LIRC_GET_MIN_TIMEOUT:
		if (!(ir->d.features & LIRC_CAN_SET_REC_TIMEOUT) ||
		    ir->d.min_timeout == 0) {
			result = -ENOTTY;
			break;
		}

		result = put_user(ir->d.min_timeout, (__u32 __user *)arg);
		break;
	case LIRC_GET_MAX_TIMEOUT:
		if (!(ir->d.features & LIRC_CAN_SET_REC_TIMEOUT) ||
		    ir->d.max_timeout == 0) {
			result = -ENOTTY;
			break;
		}

		result = put_user(ir->d.max_timeout, (__u32 __user *)arg);
		break;
	default:
		result = -ENOTTY;
	}

	mutex_unlock(&ir->irctl_lock);

	return result;
}
EXPORT_SYMBOL(lirc_dev_fop_ioctl);

ssize_t lirc_dev_fop_read(struct file *file,
			  char __user *buffer,
			  size_t length,
			  loff_t *ppos)
{
	struct irctl *ir = irctls[iminor(file_inode(file))];
	unsigned char *buf;
	int ret = 0, written = 0;
	DECLARE_WAITQUEUE(wait, current);

	if (!ir) {
		pr_err("called with invalid irctl\n");
		return -ENODEV;
	}

	if (!LIRC_CAN_REC(ir->d.features))
		return -EINVAL;

	dev_dbg(ir->d.dev, LOGHEAD "read called\n", ir->d.name, ir->d.minor);

	buf = kzalloc(ir->chunk_size, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

	if (mutex_lock_interruptible(&ir->irctl_lock)) {
		ret = -ERESTARTSYS;
		goto out_unlocked;
	}
	if (!ir->attached) {
		ret = -ENODEV;
		goto out_locked;
	}

	if (length % ir->chunk_size) {
		ret = -EINVAL;
		goto out_locked;
	}

	/*
	 * we add ourselves to the task queue before buffer check
	 * to avoid losing scan code (in case when queue is awaken somewhere
	 * between while condition checking and scheduling)
	 */
	add_wait_queue(&ir->buf->wait_poll, &wait);

	/*
	 * while we didn't provide 'length' bytes, device is opened in blocking
	 * mode and 'copy_to_user' is happy, wait for data.
	 */
	while (written < length && ret == 0) {
		if (lirc_buffer_empty(ir->buf)) {
			/* According to the read(2) man page, 'written' can be
			 * returned as less than 'length', instead of blocking
			 * again, returning -EWOULDBLOCK, or returning
			 * -ERESTARTSYS
			 */
			if (written)
				break;
			if (file->f_flags & O_NONBLOCK) {
				ret = -EWOULDBLOCK;
				break;
			}
			if (signal_pending(current)) {
				ret = -ERESTARTSYS;
				break;
			}

			mutex_unlock(&ir->irctl_lock);
			set_current_state(TASK_INTERRUPTIBLE);
			schedule();
			set_current_state(TASK_RUNNING);

			if (mutex_lock_interruptible(&ir->irctl_lock)) {
				ret = -ERESTARTSYS;
				remove_wait_queue(&ir->buf->wait_poll, &wait);
				goto out_unlocked;
			}

			if (!ir->attached) {
				ret = -ENODEV;
				goto out_locked;
			}
		} else {
			lirc_buffer_read(ir->buf, buf);
			ret = copy_to_user((void __user *)buffer+written, buf,
					   ir->buf->chunk_size);
			if (!ret)
				written += ir->buf->chunk_size;
			else
				ret = -EFAULT;
		}
	}

	remove_wait_queue(&ir->buf->wait_poll, &wait);

out_locked:
	mutex_unlock(&ir->irctl_lock);

out_unlocked:
	kfree(buf);

	return ret ? ret : written;
}
EXPORT_SYMBOL(lirc_dev_fop_read);

void *lirc_get_pdata(struct file *file)
{
	return irctls[iminor(file_inode(file))]->d.data;
}
EXPORT_SYMBOL(lirc_get_pdata);


static 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, MAX_IRCTL_DEVICES,
				     "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;
}

static void __exit lirc_dev_exit(void)
{
	class_destroy(lirc_class);
	unregister_chrdev_region(lirc_base_dev, MAX_IRCTL_DEVICES);
	pr_info("module unloaded\n");
}

module_init(lirc_dev_init);
module_exit(lirc_dev_exit);

MODULE_DESCRIPTION("LIRC base driver module");
MODULE_AUTHOR("Artur Lipowski");
MODULE_LICENSE("GPL");