summaryrefslogtreecommitdiffstats
path: root/drivers/media/media-device.c
blob: bed24372e61fcd8c8f588321ceb4243b457afc88 (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
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
/*
 * Media device
 *
 * Copyright (C) 2010 Nokia Corporation
 *
 * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 *	     Sakari Ailus <sakari.ailus@iki.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * 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.
 */

#include <linux/compat.h>
#include <linux/export.h>
#include <linux/idr.h>
#include <linux/ioctl.h>
#include <linux/media.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/usb.h>
#include <linux/version.h>

#include <media/media-device.h>
#include <media/media-devnode.h>
#include <media/media-entity.h>
#include <media/media-request.h>

#ifdef CONFIG_MEDIA_CONTROLLER

/*
 * Legacy defines from linux/media.h. This is the only place we need this
 * so we just define it here. The media.h header doesn't expose it to the
 * kernel to prevent it from being used by drivers, but here (and only here!)
 * we need it to handle the legacy behavior.
 */
#define MEDIA_ENT_SUBTYPE_MASK			0x0000ffff
#define MEDIA_ENT_T_DEVNODE_UNKNOWN		(MEDIA_ENT_F_OLD_BASE | \
						 MEDIA_ENT_SUBTYPE_MASK)

/* -----------------------------------------------------------------------------
 * Userspace API
 */

static inline void __user *media_get_uptr(__u64 arg)
{
	return (void __user *)(uintptr_t)arg;
}

static int media_device_open(struct file *filp)
{
	return 0;
}

static int media_device_close(struct file *filp)
{
	return 0;
}

static long media_device_get_info(struct media_device *dev, void *arg)
{
	struct media_device_info *info = arg;

	memset(info, 0, sizeof(*info));

	if (dev->driver_name[0])
		strscpy(info->driver, dev->driver_name, sizeof(info->driver));
	else
		strscpy(info->driver, dev->dev->driver->name,
			sizeof(info->driver));

	strscpy(info->model, dev->model, sizeof(info->model));
	strscpy(info->serial, dev->serial, sizeof(info->serial));
	strscpy(info->bus_info, dev->bus_info, sizeof(info->bus_info));

	info->media_version = LINUX_VERSION_CODE;
	info->driver_version = info->media_version;
	info->hw_revision = dev->hw_revision;

	return 0;
}

static struct media_entity *find_entity(struct media_device *mdev, u32 id)
{
	struct media_entity *entity;
	int next = id & MEDIA_ENT_ID_FLAG_NEXT;

	id &= ~MEDIA_ENT_ID_FLAG_NEXT;

	media_device_for_each_entity(entity, mdev) {
		if (((media_entity_id(entity) == id) && !next) ||
		    ((media_entity_id(entity) > id) && next)) {
			return entity;
		}
	}

	return NULL;
}

static long media_device_enum_entities(struct media_device *mdev, void *arg)
{
	struct media_entity_desc *entd = arg;
	struct media_entity *ent;

	ent = find_entity(mdev, entd->id);
	if (ent == NULL)
		return -EINVAL;

	memset(entd, 0, sizeof(*entd));

	entd->id = media_entity_id(ent);
	if (ent->name)
		strscpy(entd->name, ent->name, sizeof(entd->name));
	entd->type = ent->function;
	entd->revision = 0;		/* Unused */
	entd->flags = ent->flags;
	entd->group_id = 0;		/* Unused */
	entd->pads = ent->num_pads;
	entd->links = ent->num_links - ent->num_backlinks;

	/*
	 * Workaround for a bug at media-ctl <= v1.10 that makes it to
	 * do the wrong thing if the entity function doesn't belong to
	 * either MEDIA_ENT_F_OLD_BASE or MEDIA_ENT_F_OLD_SUBDEV_BASE
	 * Ranges.
	 *
	 * Non-subdevices are expected to be at the MEDIA_ENT_F_OLD_BASE,
	 * or, otherwise, will be silently ignored by media-ctl when
	 * printing the graphviz diagram. So, map them into the devnode
	 * old range.
	 */
	if (ent->function < MEDIA_ENT_F_OLD_BASE ||
	    ent->function > MEDIA_ENT_F_TUNER) {
		if (is_media_entity_v4l2_subdev(ent))
			entd->type = MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN;
		else if (ent->function != MEDIA_ENT_F_IO_V4L)
			entd->type = MEDIA_ENT_T_DEVNODE_UNKNOWN;
	}

	memcpy(&entd->raw, &ent->info, sizeof(ent->info));

	return 0;
}

static void media_device_kpad_to_upad(const struct media_pad *kpad,
				      struct media_pad_desc *upad)
{
	upad->entity = media_entity_id(kpad->entity);
	upad->index = kpad->index;
	upad->flags = kpad->flags;
}

static long media_device_enum_links(struct media_device *mdev, void *arg)
{
	struct media_links_enum *links = arg;
	struct media_entity *entity;

	entity = find_entity(mdev, links->entity);
	if (entity == NULL)
		return -EINVAL;

	if (links->pads) {
		unsigned int p;

		for (p = 0; p < entity->num_pads; p++) {
			struct media_pad_desc pad;

			memset(&pad, 0, sizeof(pad));
			media_device_kpad_to_upad(&entity->pads[p], &pad);
			if (copy_to_user(&links->pads[p], &pad, sizeof(pad)))
				return -EFAULT;
		}
	}

	if (links->links) {
		struct media_link *link;
		struct media_link_desc __user *ulink_desc = links->links;

		list_for_each_entry(link, &entity->links, list) {
			struct media_link_desc klink_desc;

			/* Ignore backlinks. */
			if (link->source->entity != entity)
				continue;
			memset(&klink_desc, 0, sizeof(klink_desc));
			media_device_kpad_to_upad(link->source,
						  &klink_desc.source);
			media_device_kpad_to_upad(link->sink,
						  &klink_desc.sink);
			klink_desc.flags = link->flags;
			if (copy_to_user(ulink_desc, &klink_desc,
					 sizeof(*ulink_desc)))
				return -EFAULT;
			ulink_desc++;
		}
	}
	memset(links->reserved, 0, sizeof(links->reserved));

	return 0;
}

static long media_device_setup_link(struct media_device *mdev, void *arg)
{
	struct media_link_desc *linkd = arg;
	struct media_link *link = NULL;
	struct media_entity *source;
	struct media_entity *sink;

	/* Find the source and sink entities and link.
	 */
	source = find_entity(mdev, linkd->source.entity);
	sink = find_entity(mdev, linkd->sink.entity);

	if (source == NULL || sink == NULL)
		return -EINVAL;

	if (linkd->source.index >= source->num_pads ||
	    linkd->sink.index >= sink->num_pads)
		return -EINVAL;

	link = media_entity_find_link(&source->pads[linkd->source.index],
				      &sink->pads[linkd->sink.index]);
	if (link == NULL)
		return -EINVAL;

	memset(linkd->reserved, 0, sizeof(linkd->reserved));

	/* Setup the link on both entities. */
	return __media_entity_setup_link(link, linkd->flags);
}

static long media_device_get_topology(struct media_device *mdev, void *arg)
{
	struct media_v2_topology *topo = arg;
	struct media_entity *entity;
	struct media_interface *intf;
	struct media_pad *pad;
	struct media_link *link;
	struct media_v2_entity kentity, __user *uentity;
	struct media_v2_interface kintf, __user *uintf;
	struct media_v2_pad kpad, __user *upad;
	struct media_v2_link klink, __user *ulink;
	unsigned int i;
	int ret = 0;

	topo->topology_version = mdev->topology_version;

	/* Get entities and number of entities */
	i = 0;
	uentity = media_get_uptr(topo->ptr_entities);
	media_device_for_each_entity(entity, mdev) {
		i++;
		if (ret || !uentity)
			continue;

		if (i > topo->num_entities) {
			ret = -ENOSPC;
			continue;
		}

		/* Copy fields to userspace struct if not error */
		memset(&kentity, 0, sizeof(kentity));
		kentity.id = entity->graph_obj.id;
		kentity.function = entity->function;
		kentity.flags = entity->flags;
		strscpy(kentity.name, entity->name,
			sizeof(kentity.name));

		if (copy_to_user(uentity, &kentity, sizeof(kentity)))
			ret = -EFAULT;
		uentity++;
	}
	topo->num_entities = i;
	topo->reserved1 = 0;

	/* Get interfaces and number of interfaces */
	i = 0;
	uintf = media_get_uptr(topo->ptr_interfaces);
	media_device_for_each_intf(intf, mdev) {
		i++;
		if (ret || !uintf)
			continue;

		if (i > topo->num_interfaces) {
			ret = -ENOSPC;
			continue;
		}

		memset(&kintf, 0, sizeof(kintf));

		/* Copy intf fields to userspace struct */
		kintf.id = intf->graph_obj.id;
		kintf.intf_type = intf->type;
		kintf.flags = intf->flags;

		if (media_type(&intf->graph_obj) == MEDIA_GRAPH_INTF_DEVNODE) {
			struct media_intf_devnode *devnode;

			devnode = intf_to_devnode(intf);

			kintf.devnode.major = devnode->major;
			kintf.devnode.minor = devnode->minor;
		}

		if (copy_to_user(uintf, &kintf, sizeof(kintf)))
			ret = -EFAULT;
		uintf++;
	}
	topo->num_interfaces = i;
	topo->reserved2 = 0;

	/* Get pads and number of pads */
	i = 0;
	upad = media_get_uptr(topo->ptr_pads);
	media_device_for_each_pad(pad, mdev) {
		i++;
		if (ret || !upad)
			continue;

		if (i > topo->num_pads) {
			ret = -ENOSPC;
			continue;
		}

		memset(&kpad, 0, sizeof(kpad));

		/* Copy pad fields to userspace struct */
		kpad.id = pad->graph_obj.id;
		kpad.entity_id = pad->entity->graph_obj.id;
		kpad.flags = pad->flags;
		kpad.index = pad->index;

		if (copy_to_user(upad, &kpad, sizeof(kpad)))
			ret = -EFAULT;
		upad++;
	}
	topo->num_pads = i;
	topo->reserved3 = 0;

	/* Get links and number of links */
	i = 0;
	ulink = media_get_uptr(topo->ptr_links);
	media_device_for_each_link(link, mdev) {
		if (link->is_backlink)
			continue;

		i++;

		if (ret || !ulink)
			continue;

		if (i > topo->num_links) {
			ret = -ENOSPC;
			continue;
		}

		memset(&klink, 0, sizeof(klink));

		/* Copy link fields to userspace struct */
		klink.id = link->graph_obj.id;
		klink.source_id = link->gobj0->id;
		klink.sink_id = link->gobj1->id;
		klink.flags = link->flags;

		if (copy_to_user(ulink, &klink, sizeof(klink)))
			ret = -EFAULT;
		ulink++;
	}
	topo->num_links = i;
	topo->reserved4 = 0;

	return ret;
}

static long media_device_request_alloc(struct media_device *mdev,
				       int *alloc_fd)
{
	if (!mdev->ops || !mdev->ops->req_validate || !mdev->ops->req_queue)
		return -ENOTTY;

	return media_request_alloc(mdev, alloc_fd);
}

static long copy_arg_from_user(void *karg, void __user *uarg, unsigned int cmd)
{
	if ((_IOC_DIR(cmd) & _IOC_WRITE) &&
	    copy_from_user(karg, uarg, _IOC_SIZE(cmd)))
		return -EFAULT;

	return 0;
}

static long copy_arg_to_user(void __user *uarg, void *karg, unsigned int cmd)
{
	if ((_IOC_DIR(cmd) & _IOC_READ) &&
	    copy_to_user(uarg, karg, _IOC_SIZE(cmd)))
		return -EFAULT;

	return 0;
}

/* Do acquire the graph mutex */
#define MEDIA_IOC_FL_GRAPH_MUTEX	BIT(0)

#define MEDIA_IOC_ARG(__cmd, func, fl, from_user, to_user)		\
	[_IOC_NR(MEDIA_IOC_##__cmd)] = {				\
		.cmd = MEDIA_IOC_##__cmd,				\
		.fn = (long (*)(struct media_device *, void *))func,	\
		.flags = fl,						\
		.arg_from_user = from_user,				\
		.arg_to_user = to_user,					\
	}

#define MEDIA_IOC(__cmd, func, fl)					\
	MEDIA_IOC_ARG(__cmd, func, fl, copy_arg_from_user, copy_arg_to_user)

/* the table is indexed by _IOC_NR(cmd) */
struct media_ioctl_info {
	unsigned int cmd;
	unsigned short flags;
	long (*fn)(struct media_device *dev, void *arg);
	long (*arg_from_user)(void *karg, void __user *uarg, unsigned int cmd);
	long (*arg_to_user)(void __user *uarg, void *karg, unsigned int cmd);
};

static const struct media_ioctl_info ioctl_info[] = {
	MEDIA_IOC(DEVICE_INFO, media_device_get_info, MEDIA_IOC_FL_GRAPH_MUTEX),
	MEDIA_IOC(ENUM_ENTITIES, media_device_enum_entities, MEDIA_IOC_FL_GRAPH_MUTEX),
	MEDIA_IOC(ENUM_LINKS, media_device_enum_links, MEDIA_IOC_FL_GRAPH_MUTEX),
	MEDIA_IOC(SETUP_LINK, media_device_setup_link, MEDIA_IOC_FL_GRAPH_MUTEX),
	MEDIA_IOC(G_TOPOLOGY, media_device_get_topology, MEDIA_IOC_FL_GRAPH_MUTEX),
	MEDIA_IOC(REQUEST_ALLOC, media_device_request_alloc, 0),
};

static long media_device_ioctl(struct file *filp, unsigned int cmd,
			       unsigned long __arg)
{
	struct media_devnode *devnode = media_devnode_data(filp);
	struct media_device *dev = devnode->media_dev;
	const struct media_ioctl_info *info;
	void __user *arg = (void __user *)__arg;
	char __karg[256], *karg = __karg;
	long ret;

	if (_IOC_NR(cmd) >= ARRAY_SIZE(ioctl_info)
	    || ioctl_info[_IOC_NR(cmd)].cmd != cmd)
		return -ENOIOCTLCMD;

	info = &ioctl_info[_IOC_NR(cmd)];

	if (_IOC_SIZE(info->cmd) > sizeof(__karg)) {
		karg = kmalloc(_IOC_SIZE(info->cmd), GFP_KERNEL);
		if (!karg)
			return -ENOMEM;
	}

	if (info->arg_from_user) {
		ret = info->arg_from_user(karg, arg, cmd);
		if (ret)
			goto out_free;
	}

	if (info->flags & MEDIA_IOC_FL_GRAPH_MUTEX)
		mutex_lock(&dev->graph_mutex);

	ret = info->fn(dev, karg);

	if (info->flags & MEDIA_IOC_FL_GRAPH_MUTEX)
		mutex_unlock(&dev->graph_mutex);

	if (!ret && info->arg_to_user)
		ret = info->arg_to_user(arg, karg, cmd);

out_free:
	if (karg != __karg)
		kfree(karg);

	return ret;
}

#ifdef CONFIG_COMPAT

struct media_links_enum32 {
	__u32 entity;
	compat_uptr_t pads; /* struct media_pad_desc * */
	compat_uptr_t links; /* struct media_link_desc * */
	__u32 reserved[4];
};

static long media_device_enum_links32(struct media_device *mdev,
				      struct media_links_enum32 __user *ulinks)
{
	struct media_links_enum links;
	compat_uptr_t pads_ptr, links_ptr;

	memset(&links, 0, sizeof(links));

	if (get_user(links.entity, &ulinks->entity)
	    || get_user(pads_ptr, &ulinks->pads)
	    || get_user(links_ptr, &ulinks->links))
		return -EFAULT;

	links.pads = compat_ptr(pads_ptr);
	links.links = compat_ptr(links_ptr);

	return media_device_enum_links(mdev, &links);
}

#define MEDIA_IOC_ENUM_LINKS32		_IOWR('|', 0x02, struct media_links_enum32)

static long media_device_compat_ioctl(struct file *filp, unsigned int cmd,
				      unsigned long arg)
{
	struct media_devnode *devnode = media_devnode_data(filp);
	struct media_device *dev = devnode->media_dev;
	long ret;

	switch (cmd) {
	case MEDIA_IOC_ENUM_LINKS32:
		mutex_lock(&dev->graph_mutex);
		ret = media_device_enum_links32(dev,
				(struct media_links_enum32 __user *)arg);
		mutex_unlock(&dev->graph_mutex);
		break;

	default:
		return media_device_ioctl(filp, cmd, arg);
	}

	return ret;
}
#endif /* CONFIG_COMPAT */

static const struct media_file_operations media_device_fops = {
	.owner = THIS_MODULE,
	.open = media_device_open,
	.ioctl = media_device_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl = media_device_compat_ioctl,
#endif /* CONFIG_COMPAT */
	.release = media_device_close,
};

/* -----------------------------------------------------------------------------
 * sysfs
 */

static ssize_t show_model(struct device *cd,
			  struct device_attribute *attr, char *buf)
{
	struct media_devnode *devnode = to_media_devnode(cd);
	struct media_device *mdev = devnode->media_dev;

	return sprintf(buf, "%.*s\n", (int)sizeof(mdev->model), mdev->model);
}

static DEVICE_ATTR(model, S_IRUGO, show_model, NULL);

/* -----------------------------------------------------------------------------
 * Registration/unregistration
 */

static void media_device_release(struct media_devnode *devnode)
{
	dev_dbg(devnode->parent, "Media device released\n");
}

/**
 * media_device_register_entity - Register an entity with a media device
 * @mdev:	The media device
 * @entity:	The entity
 */
int __must_check media_device_register_entity(struct media_device *mdev,
					      struct media_entity *entity)
{
	struct media_entity_notify *notify, *next;
	unsigned int i;
	int ret;

	if (entity->function == MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN ||
	    entity->function == MEDIA_ENT_F_UNKNOWN)
		dev_warn(mdev->dev,
			 "Entity type for entity %s was not initialized!\n",
			 entity->name);

	/* Warn if we apparently re-register an entity */
	WARN_ON(entity->graph_obj.mdev != NULL);
	entity->graph_obj.mdev = mdev;
	INIT_LIST_HEAD(&entity->links);
	entity->num_links = 0;
	entity->num_backlinks = 0;

	ret = ida_alloc_min(&mdev->entity_internal_idx, 1, GFP_KERNEL);
	if (ret < 0)
		return ret;
	entity->internal_idx = ret;

	mutex_lock(&mdev->graph_mutex);
	mdev->entity_internal_idx_max =
		max(mdev->entity_internal_idx_max, entity->internal_idx);

	/* Initialize media_gobj embedded at the entity */
	media_gobj_create(mdev, MEDIA_GRAPH_ENTITY, &entity->graph_obj);

	/* Initialize objects at the pads */
	for (i = 0; i < entity->num_pads; i++)
		media_gobj_create(mdev, MEDIA_GRAPH_PAD,
			       &entity->pads[i].graph_obj);

	/* invoke entity_notify callbacks */
	list_for_each_entry_safe(notify, next, &mdev->entity_notify, list)
		notify->notify(entity, notify->notify_data);

	if (mdev->entity_internal_idx_max
	    >= mdev->pm_count_walk.ent_enum.idx_max) {
		struct media_graph new = { .top = 0 };

		/*
		 * Initialise the new graph walk before cleaning up
		 * the old one in order not to spoil the graph walk
		 * object of the media device if graph walk init fails.
		 */
		ret = media_graph_walk_init(&new, mdev);
		if (ret) {
			mutex_unlock(&mdev->graph_mutex);
			return ret;
		}
		media_graph_walk_cleanup(&mdev->pm_count_walk);
		mdev->pm_count_walk = new;
	}
	mutex_unlock(&mdev->graph_mutex);

	return 0;
}
EXPORT_SYMBOL_GPL(media_device_register_entity);

static void __media_device_unregister_entity(struct media_entity *entity)
{
	struct media_device *mdev = entity->graph_obj.mdev;
	struct media_link *link, *tmp;
	struct media_interface *intf;
	unsigned int i;

	ida_free(&mdev->entity_internal_idx, entity->internal_idx);

	/* Remove all interface links pointing to this entity */
	list_for_each_entry(intf, &mdev->interfaces, graph_obj.list) {
		list_for_each_entry_safe(link, tmp, &intf->links, list) {
			if (link->entity == entity)
				__media_remove_intf_link(link);
		}
	}

	/* Remove all data links that belong to this entity */
	__media_entity_remove_links(entity);

	/* Remove all pads that belong to this entity */
	for (i = 0; i < entity->num_pads; i++)
		media_gobj_destroy(&entity->pads[i].graph_obj);

	/* Remove the entity */
	media_gobj_destroy(&entity->graph_obj);

	/* invoke entity_notify callbacks to handle entity removal?? */

	entity->graph_obj.mdev = NULL;
}

void media_device_unregister_entity(struct media_entity *entity)
{
	struct media_device *mdev = entity->graph_obj.mdev;

	if (mdev == NULL)
		return;

	mutex_lock(&mdev->graph_mutex);
	__media_device_unregister_entity(entity);
	mutex_unlock(&mdev->graph_mutex);
}
EXPORT_SYMBOL_GPL(media_device_unregister_entity);

/**
 * media_device_init() - initialize a media device
 * @mdev:	The media device
 *
 * The caller is responsible for initializing the media device before
 * registration. The following fields must be set:
 *
 * - dev must point to the parent device
 * - model must be filled with the device model name
 */
void media_device_init(struct media_device *mdev)
{
	INIT_LIST_HEAD(&mdev->entities);
	INIT_LIST_HEAD(&mdev->interfaces);
	INIT_LIST_HEAD(&mdev->pads);
	INIT_LIST_HEAD(&mdev->links);
	INIT_LIST_HEAD(&mdev->entity_notify);

	mutex_init(&mdev->req_queue_mutex);
	mutex_init(&mdev->graph_mutex);
	ida_init(&mdev->entity_internal_idx);

	atomic_set(&mdev->request_id, 0);

	dev_dbg(mdev->dev, "Media device initialized\n");
}
EXPORT_SYMBOL_GPL(media_device_init);

void media_device_cleanup(struct media_device *mdev)
{
	ida_destroy(&mdev->entity_internal_idx);
	mdev->entity_internal_idx_max = 0;
	media_graph_walk_cleanup(&mdev->pm_count_walk);
	mutex_destroy(&mdev->graph_mutex);
	mutex_destroy(&mdev->req_queue_mutex);
}
EXPORT_SYMBOL_GPL(media_device_cleanup);

int __must_check __media_device_register(struct media_device *mdev,
					 struct module *owner)
{
	struct media_devnode *devnode;
	int ret;

	devnode = kzalloc(sizeof(*devnode), GFP_KERNEL);
	if (!devnode)
		return -ENOMEM;

	/* Register the device node. */
	mdev->devnode = devnode;
	devnode->fops = &media_device_fops;
	devnode->parent = mdev->dev;
	devnode->release = media_device_release;

	/* Set version 0 to indicate user-space that the graph is static */
	mdev->topology_version = 0;

	ret = media_devnode_register(mdev, devnode, owner);
	if (ret < 0) {
		/* devnode free is handled in media_devnode_*() */
		mdev->devnode = NULL;
		return ret;
	}

	ret = device_create_file(&devnode->dev, &dev_attr_model);
	if (ret < 0) {
		/* devnode free is handled in media_devnode_*() */
		mdev->devnode = NULL;
		media_devnode_unregister_prepare(devnode);
		media_devnode_unregister(devnode);
		return ret;
	}

	dev_dbg(mdev->dev, "Media device registered\n");

	return 0;
}
EXPORT_SYMBOL_GPL(__media_device_register);

int __must_check media_device_register_entity_notify(struct media_device *mdev,
					struct media_entity_notify *nptr)
{
	mutex_lock(&mdev->graph_mutex);
	list_add_tail(&nptr->list, &mdev->entity_notify);
	mutex_unlock(&mdev->graph_mutex);
	return 0;
}
EXPORT_SYMBOL_GPL(media_device_register_entity_notify);

/*
 * Note: Should be called with mdev->lock held.
 */
static void __media_device_unregister_entity_notify(struct media_device *mdev,
					struct media_entity_notify *nptr)
{
	list_del(&nptr->list);
}

void media_device_unregister_entity_notify(struct media_device *mdev,
					struct media_entity_notify *nptr)
{
	mutex_lock(&mdev->graph_mutex);
	__media_device_unregister_entity_notify(mdev, nptr);
	mutex_unlock(&mdev->graph_mutex);
}
EXPORT_SYMBOL_GPL(media_device_unregister_entity_notify);

void media_device_unregister(struct media_device *mdev)
{
	struct media_entity *entity;
	struct media_entity *next;
	struct media_interface *intf, *tmp_intf;
	struct media_entity_notify *notify, *nextp;

	if (mdev == NULL)
		return;

	mutex_lock(&mdev->graph_mutex);

	/* Check if mdev was ever registered at all */
	if (!media_devnode_is_registered(mdev->devnode)) {
		mutex_unlock(&mdev->graph_mutex);
		return;
	}

	/* Clear the devnode register bit to avoid races with media dev open */
	media_devnode_unregister_prepare(mdev->devnode);

	/* Remove all entities from the media device */
	list_for_each_entry_safe(entity, next, &mdev->entities, graph_obj.list)
		__media_device_unregister_entity(entity);

	/* Remove all entity_notify callbacks from the media device */
	list_for_each_entry_safe(notify, nextp, &mdev->entity_notify, list)
		__media_device_unregister_entity_notify(mdev, notify);

	/* Remove all interfaces from the media device */
	list_for_each_entry_safe(intf, tmp_intf, &mdev->interfaces,
				 graph_obj.list) {
		/*
		 * Unlink the interface, but don't free it here; the
		 * module which created it is responsible for freeing
		 * it
		 */
		__media_remove_intf_links(intf);
		media_gobj_destroy(&intf->graph_obj);
	}

	mutex_unlock(&mdev->graph_mutex);

	dev_dbg(mdev->dev, "Media device unregistered\n");

	device_remove_file(&mdev->devnode->dev, &dev_attr_model);
	media_devnode_unregister(mdev->devnode);
	/* devnode free is handled in media_devnode_*() */
	mdev->devnode = NULL;
}
EXPORT_SYMBOL_GPL(media_device_unregister);

#if IS_ENABLED(CONFIG_PCI)
void media_device_pci_init(struct media_device *mdev,
			   struct pci_dev *pci_dev,
			   const char *name)
{
	mdev->dev = &pci_dev->dev;

	if (name)
		strscpy(mdev->model, name, sizeof(mdev->model));
	else
		strscpy(mdev->model, pci_name(pci_dev), sizeof(mdev->model));

	sprintf(mdev->bus_info, "PCI:%s", pci_name(pci_dev));

	mdev->hw_revision = (pci_dev->subsystem_vendor << 16)
			    | pci_dev->subsystem_device;

	media_device_init(mdev);
}
EXPORT_SYMBOL_GPL(media_device_pci_init);
#endif

#if IS_ENABLED(CONFIG_USB)
void __media_device_usb_init(struct media_device *mdev,
			     struct usb_device *udev,
			     const char *board_name,
			     const char *driver_name)
{
	mdev->dev = &udev->dev;

	if (driver_name)
		strscpy(mdev->driver_name, driver_name,
			sizeof(mdev->driver_name));

	if (board_name)
		strscpy(mdev->model, board_name, sizeof(mdev->model));
	else if (udev->product)
		strscpy(mdev->model, udev->product, sizeof(mdev->model));
	else
		strscpy(mdev->model, "unknown model", sizeof(mdev->model));
	if (udev->serial)
		strscpy(mdev->serial, udev->serial, sizeof(mdev->serial));
	usb_make_path(udev, mdev->bus_info, sizeof(mdev->bus_info));
	mdev->hw_revision = le16_to_cpu(udev->descriptor.bcdDevice);

	media_device_init(mdev);
}
EXPORT_SYMBOL_GPL(__media_device_usb_init);
#endif


#endif /* CONFIG_MEDIA_CONTROLLER */