xref: /linux/drivers/media/mc/mc-device.c (revision 6c363eafc4d637ac4bd83d4a7dd06dd3cfbe7c5f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Media device
4  *
5  * Copyright (C) 2010 Nokia Corporation
6  *
7  * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
8  *	     Sakari Ailus <sakari.ailus@iki.fi>
9  */
10 
11 #include <linux/compat.h>
12 #include <linux/export.h>
13 #include <linux/idr.h>
14 #include <linux/ioctl.h>
15 #include <linux/media.h>
16 #include <linux/slab.h>
17 #include <linux/types.h>
18 #include <linux/pci.h>
19 #include <linux/usb.h>
20 #include <linux/version.h>
21 
22 #include <media/media-device.h>
23 #include <media/media-devnode.h>
24 #include <media/media-entity.h>
25 #include <media/media-request.h>
26 
27 #ifdef CONFIG_MEDIA_CONTROLLER
28 
29 /*
30  * Legacy defines from linux/media.h. This is the only place we need this
31  * so we just define it here. The media.h header doesn't expose it to the
32  * kernel to prevent it from being used by drivers, but here (and only here!)
33  * we need it to handle the legacy behavior.
34  */
35 #define MEDIA_ENT_SUBTYPE_MASK			0x0000ffff
36 #define MEDIA_ENT_T_DEVNODE_UNKNOWN		(MEDIA_ENT_F_OLD_BASE | \
37 						 MEDIA_ENT_SUBTYPE_MASK)
38 
39 /* -----------------------------------------------------------------------------
40  * Userspace API
41  */
42 
43 static inline void __user *media_get_uptr(__u64 arg)
44 {
45 	return (void __user *)(uintptr_t)arg;
46 }
47 
48 static int media_device_open(struct file *filp)
49 {
50 	return 0;
51 }
52 
53 static int media_device_close(struct file *filp)
54 {
55 	return 0;
56 }
57 
58 static long media_device_get_info(struct media_device *dev, void *arg)
59 {
60 	struct media_device_info *info = arg;
61 
62 	memset(info, 0, sizeof(*info));
63 
64 	if (dev->driver_name[0])
65 		strscpy(info->driver, dev->driver_name, sizeof(info->driver));
66 	else
67 		strscpy(info->driver, dev->dev->driver->name,
68 			sizeof(info->driver));
69 
70 	strscpy(info->model, dev->model, sizeof(info->model));
71 	strscpy(info->serial, dev->serial, sizeof(info->serial));
72 	strscpy(info->bus_info, dev->bus_info, sizeof(info->bus_info));
73 
74 	info->media_version = LINUX_VERSION_CODE;
75 	info->driver_version = info->media_version;
76 	info->hw_revision = dev->hw_revision;
77 
78 	return 0;
79 }
80 
81 static struct media_entity *find_entity(struct media_device *mdev, u32 id)
82 {
83 	struct media_entity *entity;
84 	int next = id & MEDIA_ENT_ID_FLAG_NEXT;
85 
86 	id &= ~MEDIA_ENT_ID_FLAG_NEXT;
87 
88 	media_device_for_each_entity(entity, mdev) {
89 		if (((media_entity_id(entity) == id) && !next) ||
90 		    ((media_entity_id(entity) > id) && next)) {
91 			return entity;
92 		}
93 	}
94 
95 	return NULL;
96 }
97 
98 static long media_device_enum_entities(struct media_device *mdev, void *arg)
99 {
100 	struct media_entity_desc *entd = arg;
101 	struct media_entity *ent;
102 
103 	ent = find_entity(mdev, entd->id);
104 	if (ent == NULL)
105 		return -EINVAL;
106 
107 	memset(entd, 0, sizeof(*entd));
108 
109 	entd->id = media_entity_id(ent);
110 	if (ent->name)
111 		strscpy(entd->name, ent->name, sizeof(entd->name));
112 	entd->type = ent->function;
113 	entd->revision = 0;		/* Unused */
114 	entd->flags = ent->flags;
115 	entd->group_id = 0;		/* Unused */
116 	entd->pads = ent->num_pads;
117 	entd->links = ent->num_links - ent->num_backlinks;
118 
119 	/*
120 	 * Workaround for a bug at media-ctl <= v1.10 that makes it to
121 	 * do the wrong thing if the entity function doesn't belong to
122 	 * either MEDIA_ENT_F_OLD_BASE or MEDIA_ENT_F_OLD_SUBDEV_BASE
123 	 * Ranges.
124 	 *
125 	 * Non-subdevices are expected to be at the MEDIA_ENT_F_OLD_BASE,
126 	 * or, otherwise, will be silently ignored by media-ctl when
127 	 * printing the graphviz diagram. So, map them into the devnode
128 	 * old range.
129 	 */
130 	if (ent->function < MEDIA_ENT_F_OLD_BASE ||
131 	    ent->function > MEDIA_ENT_F_TUNER) {
132 		if (is_media_entity_v4l2_subdev(ent))
133 			entd->type = MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN;
134 		else if (ent->function != MEDIA_ENT_F_IO_V4L)
135 			entd->type = MEDIA_ENT_T_DEVNODE_UNKNOWN;
136 	}
137 
138 	memcpy(&entd->raw, &ent->info, sizeof(ent->info));
139 
140 	return 0;
141 }
142 
143 static void media_device_kpad_to_upad(const struct media_pad *kpad,
144 				      struct media_pad_desc *upad)
145 {
146 	upad->entity = media_entity_id(kpad->entity);
147 	upad->index = kpad->index;
148 	upad->flags = kpad->flags;
149 }
150 
151 static long media_device_enum_links(struct media_device *mdev, void *arg)
152 {
153 	struct media_links_enum *links = arg;
154 	struct media_entity *entity;
155 
156 	entity = find_entity(mdev, links->entity);
157 	if (entity == NULL)
158 		return -EINVAL;
159 
160 	if (links->pads) {
161 		unsigned int p;
162 
163 		for (p = 0; p < entity->num_pads; p++) {
164 			struct media_pad_desc pad;
165 
166 			memset(&pad, 0, sizeof(pad));
167 			media_device_kpad_to_upad(&entity->pads[p], &pad);
168 			if (copy_to_user(&links->pads[p], &pad, sizeof(pad)))
169 				return -EFAULT;
170 		}
171 	}
172 
173 	if (links->links) {
174 		struct media_link *link;
175 		struct media_link_desc __user *ulink_desc = links->links;
176 
177 		list_for_each_entry(link, &entity->links, list) {
178 			struct media_link_desc klink_desc;
179 
180 			/* Ignore backlinks. */
181 			if (link->source->entity != entity)
182 				continue;
183 			memset(&klink_desc, 0, sizeof(klink_desc));
184 			media_device_kpad_to_upad(link->source,
185 						  &klink_desc.source);
186 			media_device_kpad_to_upad(link->sink,
187 						  &klink_desc.sink);
188 			klink_desc.flags = link->flags;
189 			if (copy_to_user(ulink_desc, &klink_desc,
190 					 sizeof(*ulink_desc)))
191 				return -EFAULT;
192 			ulink_desc++;
193 		}
194 	}
195 	memset(links->reserved, 0, sizeof(links->reserved));
196 
197 	return 0;
198 }
199 
200 static long media_device_setup_link(struct media_device *mdev, void *arg)
201 {
202 	struct media_link_desc *linkd = arg;
203 	struct media_link *link = NULL;
204 	struct media_entity *source;
205 	struct media_entity *sink;
206 
207 	/* Find the source and sink entities and link.
208 	 */
209 	source = find_entity(mdev, linkd->source.entity);
210 	sink = find_entity(mdev, linkd->sink.entity);
211 
212 	if (source == NULL || sink == NULL)
213 		return -EINVAL;
214 
215 	if (linkd->source.index >= source->num_pads ||
216 	    linkd->sink.index >= sink->num_pads)
217 		return -EINVAL;
218 
219 	link = media_entity_find_link(&source->pads[linkd->source.index],
220 				      &sink->pads[linkd->sink.index]);
221 	if (link == NULL)
222 		return -EINVAL;
223 
224 	memset(linkd->reserved, 0, sizeof(linkd->reserved));
225 
226 	/* Setup the link on both entities. */
227 	return __media_entity_setup_link(link, linkd->flags);
228 }
229 
230 static long media_device_get_topology(struct media_device *mdev, void *arg)
231 {
232 	struct media_v2_topology *topo = arg;
233 	struct media_entity *entity;
234 	struct media_interface *intf;
235 	struct media_pad *pad;
236 	struct media_link *link;
237 	struct media_v2_entity kentity, __user *uentity;
238 	struct media_v2_interface kintf, __user *uintf;
239 	struct media_v2_pad kpad, __user *upad;
240 	struct media_v2_link klink, __user *ulink;
241 	unsigned int i;
242 	int ret = 0;
243 
244 	topo->topology_version = mdev->topology_version;
245 
246 	/* Get entities and number of entities */
247 	i = 0;
248 	uentity = media_get_uptr(topo->ptr_entities);
249 	media_device_for_each_entity(entity, mdev) {
250 		i++;
251 		if (ret || !uentity)
252 			continue;
253 
254 		if (i > topo->num_entities) {
255 			ret = -ENOSPC;
256 			continue;
257 		}
258 
259 		/* Copy fields to userspace struct if not error */
260 		memset(&kentity, 0, sizeof(kentity));
261 		kentity.id = entity->graph_obj.id;
262 		kentity.function = entity->function;
263 		kentity.flags = entity->flags;
264 		strscpy(kentity.name, entity->name,
265 			sizeof(kentity.name));
266 
267 		if (copy_to_user(uentity, &kentity, sizeof(kentity)))
268 			ret = -EFAULT;
269 		uentity++;
270 	}
271 	topo->num_entities = i;
272 	topo->reserved1 = 0;
273 
274 	/* Get interfaces and number of interfaces */
275 	i = 0;
276 	uintf = media_get_uptr(topo->ptr_interfaces);
277 	media_device_for_each_intf(intf, mdev) {
278 		i++;
279 		if (ret || !uintf)
280 			continue;
281 
282 		if (i > topo->num_interfaces) {
283 			ret = -ENOSPC;
284 			continue;
285 		}
286 
287 		memset(&kintf, 0, sizeof(kintf));
288 
289 		/* Copy intf fields to userspace struct */
290 		kintf.id = intf->graph_obj.id;
291 		kintf.intf_type = intf->type;
292 		kintf.flags = intf->flags;
293 
294 		if (media_type(&intf->graph_obj) == MEDIA_GRAPH_INTF_DEVNODE) {
295 			struct media_intf_devnode *devnode;
296 
297 			devnode = intf_to_devnode(intf);
298 
299 			kintf.devnode.major = devnode->major;
300 			kintf.devnode.minor = devnode->minor;
301 		}
302 
303 		if (copy_to_user(uintf, &kintf, sizeof(kintf)))
304 			ret = -EFAULT;
305 		uintf++;
306 	}
307 	topo->num_interfaces = i;
308 	topo->reserved2 = 0;
309 
310 	/* Get pads and number of pads */
311 	i = 0;
312 	upad = media_get_uptr(topo->ptr_pads);
313 	media_device_for_each_pad(pad, mdev) {
314 		i++;
315 		if (ret || !upad)
316 			continue;
317 
318 		if (i > topo->num_pads) {
319 			ret = -ENOSPC;
320 			continue;
321 		}
322 
323 		memset(&kpad, 0, sizeof(kpad));
324 
325 		/* Copy pad fields to userspace struct */
326 		kpad.id = pad->graph_obj.id;
327 		kpad.entity_id = pad->entity->graph_obj.id;
328 		kpad.flags = pad->flags;
329 		kpad.index = pad->index;
330 
331 		if (copy_to_user(upad, &kpad, sizeof(kpad)))
332 			ret = -EFAULT;
333 		upad++;
334 	}
335 	topo->num_pads = i;
336 	topo->reserved3 = 0;
337 
338 	/* Get links and number of links */
339 	i = 0;
340 	ulink = media_get_uptr(topo->ptr_links);
341 	media_device_for_each_link(link, mdev) {
342 		if (link->is_backlink)
343 			continue;
344 
345 		i++;
346 
347 		if (ret || !ulink)
348 			continue;
349 
350 		if (i > topo->num_links) {
351 			ret = -ENOSPC;
352 			continue;
353 		}
354 
355 		memset(&klink, 0, sizeof(klink));
356 
357 		/* Copy link fields to userspace struct */
358 		klink.id = link->graph_obj.id;
359 		klink.source_id = link->gobj0->id;
360 		klink.sink_id = link->gobj1->id;
361 		klink.flags = link->flags;
362 
363 		if (copy_to_user(ulink, &klink, sizeof(klink)))
364 			ret = -EFAULT;
365 		ulink++;
366 	}
367 	topo->num_links = i;
368 	topo->reserved4 = 0;
369 
370 	return ret;
371 }
372 
373 static long media_device_request_alloc(struct media_device *mdev, void *arg)
374 {
375 #ifdef CONFIG_MEDIA_CONTROLLER_REQUEST_API
376 	int *alloc_fd = arg;
377 
378 	if (!mdev->ops || !mdev->ops->req_validate || !mdev->ops->req_queue)
379 		return -ENOTTY;
380 
381 	return media_request_alloc(mdev, alloc_fd);
382 #else
383 	return -ENOTTY;
384 #endif
385 }
386 
387 static long copy_arg_from_user(void *karg, void __user *uarg, unsigned int cmd)
388 {
389 	if ((_IOC_DIR(cmd) & _IOC_WRITE) &&
390 	    copy_from_user(karg, uarg, _IOC_SIZE(cmd)))
391 		return -EFAULT;
392 
393 	return 0;
394 }
395 
396 static long copy_arg_to_user(void __user *uarg, void *karg, unsigned int cmd)
397 {
398 	if ((_IOC_DIR(cmd) & _IOC_READ) &&
399 	    copy_to_user(uarg, karg, _IOC_SIZE(cmd)))
400 		return -EFAULT;
401 
402 	return 0;
403 }
404 
405 /* Do acquire the graph mutex */
406 #define MEDIA_IOC_FL_GRAPH_MUTEX	BIT(0)
407 
408 #define MEDIA_IOC_ARG(__cmd, func, fl, from_user, to_user)		\
409 	[_IOC_NR(MEDIA_IOC_##__cmd)] = {				\
410 		.cmd = MEDIA_IOC_##__cmd,				\
411 		.fn = func,						\
412 		.flags = fl,						\
413 		.arg_from_user = from_user,				\
414 		.arg_to_user = to_user,					\
415 	}
416 
417 #define MEDIA_IOC(__cmd, func, fl)					\
418 	MEDIA_IOC_ARG(__cmd, func, fl, copy_arg_from_user, copy_arg_to_user)
419 
420 /* the table is indexed by _IOC_NR(cmd) */
421 struct media_ioctl_info {
422 	unsigned int cmd;
423 	unsigned short flags;
424 	long (*fn)(struct media_device *dev, void *arg);
425 	long (*arg_from_user)(void *karg, void __user *uarg, unsigned int cmd);
426 	long (*arg_to_user)(void __user *uarg, void *karg, unsigned int cmd);
427 };
428 
429 static const struct media_ioctl_info ioctl_info[] = {
430 	MEDIA_IOC(DEVICE_INFO, media_device_get_info, MEDIA_IOC_FL_GRAPH_MUTEX),
431 	MEDIA_IOC(ENUM_ENTITIES, media_device_enum_entities, MEDIA_IOC_FL_GRAPH_MUTEX),
432 	MEDIA_IOC(ENUM_LINKS, media_device_enum_links, MEDIA_IOC_FL_GRAPH_MUTEX),
433 	MEDIA_IOC(SETUP_LINK, media_device_setup_link, MEDIA_IOC_FL_GRAPH_MUTEX),
434 	MEDIA_IOC(G_TOPOLOGY, media_device_get_topology, MEDIA_IOC_FL_GRAPH_MUTEX),
435 	MEDIA_IOC(REQUEST_ALLOC, media_device_request_alloc, 0),
436 };
437 
438 static long media_device_ioctl(struct file *filp, unsigned int cmd,
439 			       unsigned long __arg)
440 {
441 	struct media_devnode *devnode = media_devnode_data(filp);
442 	struct media_device *dev = devnode->media_dev;
443 	const struct media_ioctl_info *info;
444 	void __user *arg = (void __user *)__arg;
445 	char __karg[256], *karg = __karg;
446 	long ret;
447 
448 	if (_IOC_NR(cmd) >= ARRAY_SIZE(ioctl_info)
449 	    || ioctl_info[_IOC_NR(cmd)].cmd != cmd)
450 		return -ENOIOCTLCMD;
451 
452 	info = &ioctl_info[_IOC_NR(cmd)];
453 
454 	if (_IOC_SIZE(info->cmd) > sizeof(__karg)) {
455 		karg = kmalloc(_IOC_SIZE(info->cmd), GFP_KERNEL);
456 		if (!karg)
457 			return -ENOMEM;
458 	}
459 
460 	if (info->arg_from_user) {
461 		ret = info->arg_from_user(karg, arg, cmd);
462 		if (ret)
463 			goto out_free;
464 	}
465 
466 	if (info->flags & MEDIA_IOC_FL_GRAPH_MUTEX)
467 		mutex_lock(&dev->graph_mutex);
468 
469 	ret = info->fn(dev, karg);
470 
471 	if (info->flags & MEDIA_IOC_FL_GRAPH_MUTEX)
472 		mutex_unlock(&dev->graph_mutex);
473 
474 	if (!ret && info->arg_to_user)
475 		ret = info->arg_to_user(arg, karg, cmd);
476 
477 out_free:
478 	if (karg != __karg)
479 		kfree(karg);
480 
481 	return ret;
482 }
483 
484 #ifdef CONFIG_COMPAT
485 
486 struct media_links_enum32 {
487 	__u32 entity;
488 	compat_uptr_t pads; /* struct media_pad_desc * */
489 	compat_uptr_t links; /* struct media_link_desc * */
490 	__u32 reserved[4];
491 };
492 
493 static long media_device_enum_links32(struct media_device *mdev,
494 				      struct media_links_enum32 __user *ulinks)
495 {
496 	struct media_links_enum links;
497 	compat_uptr_t pads_ptr, links_ptr;
498 	int ret;
499 
500 	memset(&links, 0, sizeof(links));
501 
502 	if (get_user(links.entity, &ulinks->entity)
503 	    || get_user(pads_ptr, &ulinks->pads)
504 	    || get_user(links_ptr, &ulinks->links))
505 		return -EFAULT;
506 
507 	links.pads = compat_ptr(pads_ptr);
508 	links.links = compat_ptr(links_ptr);
509 
510 	ret = media_device_enum_links(mdev, &links);
511 	if (ret)
512 		return ret;
513 
514 	if (copy_to_user(ulinks->reserved, links.reserved,
515 			 sizeof(ulinks->reserved)))
516 		return -EFAULT;
517 	return 0;
518 }
519 
520 #define MEDIA_IOC_ENUM_LINKS32		_IOWR('|', 0x02, struct media_links_enum32)
521 
522 static long media_device_compat_ioctl(struct file *filp, unsigned int cmd,
523 				      unsigned long arg)
524 {
525 	struct media_devnode *devnode = media_devnode_data(filp);
526 	struct media_device *dev = devnode->media_dev;
527 	long ret;
528 
529 	switch (cmd) {
530 	case MEDIA_IOC_ENUM_LINKS32:
531 		mutex_lock(&dev->graph_mutex);
532 		ret = media_device_enum_links32(dev,
533 				(struct media_links_enum32 __user *)arg);
534 		mutex_unlock(&dev->graph_mutex);
535 		break;
536 
537 	default:
538 		return media_device_ioctl(filp, cmd, arg);
539 	}
540 
541 	return ret;
542 }
543 #endif /* CONFIG_COMPAT */
544 
545 static const struct media_file_operations media_device_fops = {
546 	.owner = THIS_MODULE,
547 	.open = media_device_open,
548 	.ioctl = media_device_ioctl,
549 #ifdef CONFIG_COMPAT
550 	.compat_ioctl = media_device_compat_ioctl,
551 #endif /* CONFIG_COMPAT */
552 	.release = media_device_close,
553 };
554 
555 /* -----------------------------------------------------------------------------
556  * sysfs
557  */
558 
559 static ssize_t show_model(struct device *cd,
560 			  struct device_attribute *attr, char *buf)
561 {
562 	struct media_devnode *devnode = to_media_devnode(cd);
563 	struct media_device *mdev = devnode->media_dev;
564 
565 	return sprintf(buf, "%.*s\n", (int)sizeof(mdev->model), mdev->model);
566 }
567 
568 static DEVICE_ATTR(model, S_IRUGO, show_model, NULL);
569 
570 /* -----------------------------------------------------------------------------
571  * Registration/unregistration
572  */
573 
574 static void media_device_release(struct media_devnode *devnode)
575 {
576 	dev_dbg(devnode->parent, "Media device released\n");
577 }
578 
579 static void __media_device_unregister_entity(struct media_entity *entity)
580 {
581 	struct media_device *mdev = entity->graph_obj.mdev;
582 	struct media_link *link, *tmp;
583 	struct media_interface *intf;
584 	unsigned int i;
585 
586 	ida_free(&mdev->entity_internal_idx, entity->internal_idx);
587 
588 	/* Remove all interface links pointing to this entity */
589 	list_for_each_entry(intf, &mdev->interfaces, graph_obj.list) {
590 		list_for_each_entry_safe(link, tmp, &intf->links, list) {
591 			if (link->entity == entity)
592 				__media_remove_intf_link(link);
593 		}
594 	}
595 
596 	/* Remove all data links that belong to this entity */
597 	__media_entity_remove_links(entity);
598 
599 	/* Remove all pads that belong to this entity */
600 	for (i = 0; i < entity->num_pads; i++)
601 		media_gobj_destroy(&entity->pads[i].graph_obj);
602 
603 	/* Remove the entity */
604 	media_gobj_destroy(&entity->graph_obj);
605 
606 	/* invoke entity_notify callbacks to handle entity removal?? */
607 
608 	entity->graph_obj.mdev = NULL;
609 }
610 
611 /**
612  * media_device_register_entity - Register an entity with a media device
613  * @mdev:	The media device
614  * @entity:	The entity
615  */
616 int __must_check media_device_register_entity(struct media_device *mdev,
617 					      struct media_entity *entity)
618 {
619 	struct media_entity_notify *notify, *next;
620 	unsigned int i;
621 	int ret;
622 
623 	if (entity->function == MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN ||
624 	    entity->function == MEDIA_ENT_F_UNKNOWN)
625 		dev_warn(mdev->dev,
626 			 "Entity type for entity %s was not initialized!\n",
627 			 entity->name);
628 
629 	/* Warn if we apparently re-register an entity */
630 	WARN_ON(entity->graph_obj.mdev != NULL);
631 	entity->graph_obj.mdev = mdev;
632 	INIT_LIST_HEAD(&entity->links);
633 	entity->num_links = 0;
634 	entity->num_backlinks = 0;
635 
636 	ret = ida_alloc_min(&mdev->entity_internal_idx, 1, GFP_KERNEL);
637 	if (ret < 0)
638 		return ret;
639 	entity->internal_idx = ret;
640 
641 	mutex_lock(&mdev->graph_mutex);
642 	mdev->entity_internal_idx_max =
643 		max(mdev->entity_internal_idx_max, entity->internal_idx);
644 
645 	/* Initialize media_gobj embedded at the entity */
646 	media_gobj_create(mdev, MEDIA_GRAPH_ENTITY, &entity->graph_obj);
647 
648 	/* Initialize objects at the pads */
649 	for (i = 0; i < entity->num_pads; i++)
650 		media_gobj_create(mdev, MEDIA_GRAPH_PAD,
651 			       &entity->pads[i].graph_obj);
652 
653 	/* invoke entity_notify callbacks */
654 	list_for_each_entry_safe(notify, next, &mdev->entity_notify, list)
655 		notify->notify(entity, notify->notify_data);
656 
657 	if (mdev->entity_internal_idx_max
658 	    >= mdev->pm_count_walk.ent_enum.idx_max) {
659 		struct media_graph new = { .top = 0 };
660 
661 		/*
662 		 * Initialise the new graph walk before cleaning up
663 		 * the old one in order not to spoil the graph walk
664 		 * object of the media device if graph walk init fails.
665 		 */
666 		ret = media_graph_walk_init(&new, mdev);
667 		if (ret) {
668 			__media_device_unregister_entity(entity);
669 			mutex_unlock(&mdev->graph_mutex);
670 			return ret;
671 		}
672 		media_graph_walk_cleanup(&mdev->pm_count_walk);
673 		mdev->pm_count_walk = new;
674 	}
675 	mutex_unlock(&mdev->graph_mutex);
676 
677 	return 0;
678 }
679 EXPORT_SYMBOL_GPL(media_device_register_entity);
680 
681 void media_device_unregister_entity(struct media_entity *entity)
682 {
683 	struct media_device *mdev = entity->graph_obj.mdev;
684 
685 	if (mdev == NULL)
686 		return;
687 
688 	mutex_lock(&mdev->graph_mutex);
689 	__media_device_unregister_entity(entity);
690 	mutex_unlock(&mdev->graph_mutex);
691 }
692 EXPORT_SYMBOL_GPL(media_device_unregister_entity);
693 
694 /**
695  * media_device_init() - initialize a media device
696  * @mdev:	The media device
697  *
698  * The caller is responsible for initializing the media device before
699  * registration. The following fields must be set:
700  *
701  * - dev must point to the parent device
702  * - model must be filled with the device model name
703  */
704 void media_device_init(struct media_device *mdev)
705 {
706 	INIT_LIST_HEAD(&mdev->entities);
707 	INIT_LIST_HEAD(&mdev->interfaces);
708 	INIT_LIST_HEAD(&mdev->pads);
709 	INIT_LIST_HEAD(&mdev->links);
710 	INIT_LIST_HEAD(&mdev->entity_notify);
711 
712 	mutex_init(&mdev->req_queue_mutex);
713 	mutex_init(&mdev->graph_mutex);
714 	ida_init(&mdev->entity_internal_idx);
715 
716 	atomic_set(&mdev->request_id, 0);
717 
718 	dev_dbg(mdev->dev, "Media device initialized\n");
719 }
720 EXPORT_SYMBOL_GPL(media_device_init);
721 
722 void media_device_cleanup(struct media_device *mdev)
723 {
724 	ida_destroy(&mdev->entity_internal_idx);
725 	mdev->entity_internal_idx_max = 0;
726 	media_graph_walk_cleanup(&mdev->pm_count_walk);
727 	mutex_destroy(&mdev->graph_mutex);
728 	mutex_destroy(&mdev->req_queue_mutex);
729 }
730 EXPORT_SYMBOL_GPL(media_device_cleanup);
731 
732 int __must_check __media_device_register(struct media_device *mdev,
733 					 struct module *owner)
734 {
735 	struct media_devnode *devnode;
736 	int ret;
737 
738 	devnode = kzalloc(sizeof(*devnode), GFP_KERNEL);
739 	if (!devnode)
740 		return -ENOMEM;
741 
742 	/* Register the device node. */
743 	mdev->devnode = devnode;
744 	devnode->fops = &media_device_fops;
745 	devnode->parent = mdev->dev;
746 	devnode->release = media_device_release;
747 
748 	/* Set version 0 to indicate user-space that the graph is static */
749 	mdev->topology_version = 0;
750 
751 	ret = media_devnode_register(mdev, devnode, owner);
752 	if (ret < 0) {
753 		/* devnode free is handled in media_devnode_*() */
754 		mdev->devnode = NULL;
755 		return ret;
756 	}
757 
758 	ret = device_create_file(&devnode->dev, &dev_attr_model);
759 	if (ret < 0) {
760 		/* devnode free is handled in media_devnode_*() */
761 		mdev->devnode = NULL;
762 		media_devnode_unregister_prepare(devnode);
763 		media_devnode_unregister(devnode);
764 		return ret;
765 	}
766 
767 	dev_dbg(mdev->dev, "Media device registered\n");
768 
769 	return 0;
770 }
771 EXPORT_SYMBOL_GPL(__media_device_register);
772 
773 int __must_check media_device_register_entity_notify(struct media_device *mdev,
774 					struct media_entity_notify *nptr)
775 {
776 	mutex_lock(&mdev->graph_mutex);
777 	list_add_tail(&nptr->list, &mdev->entity_notify);
778 	mutex_unlock(&mdev->graph_mutex);
779 	return 0;
780 }
781 EXPORT_SYMBOL_GPL(media_device_register_entity_notify);
782 
783 /*
784  * Note: Should be called with mdev->lock held.
785  */
786 static void __media_device_unregister_entity_notify(struct media_device *mdev,
787 					struct media_entity_notify *nptr)
788 {
789 	list_del(&nptr->list);
790 }
791 
792 void media_device_unregister_entity_notify(struct media_device *mdev,
793 					struct media_entity_notify *nptr)
794 {
795 	mutex_lock(&mdev->graph_mutex);
796 	__media_device_unregister_entity_notify(mdev, nptr);
797 	mutex_unlock(&mdev->graph_mutex);
798 }
799 EXPORT_SYMBOL_GPL(media_device_unregister_entity_notify);
800 
801 void media_device_unregister(struct media_device *mdev)
802 {
803 	struct media_entity *entity;
804 	struct media_entity *next;
805 	struct media_interface *intf, *tmp_intf;
806 	struct media_entity_notify *notify, *nextp;
807 
808 	if (mdev == NULL)
809 		return;
810 
811 	mutex_lock(&mdev->graph_mutex);
812 
813 	/* Check if mdev was ever registered at all */
814 	if (!media_devnode_is_registered(mdev->devnode)) {
815 		mutex_unlock(&mdev->graph_mutex);
816 		return;
817 	}
818 
819 	/* Clear the devnode register bit to avoid races with media dev open */
820 	media_devnode_unregister_prepare(mdev->devnode);
821 
822 	/* Remove all entities from the media device */
823 	list_for_each_entry_safe(entity, next, &mdev->entities, graph_obj.list)
824 		__media_device_unregister_entity(entity);
825 
826 	/* Remove all entity_notify callbacks from the media device */
827 	list_for_each_entry_safe(notify, nextp, &mdev->entity_notify, list)
828 		__media_device_unregister_entity_notify(mdev, notify);
829 
830 	/* Remove all interfaces from the media device */
831 	list_for_each_entry_safe(intf, tmp_intf, &mdev->interfaces,
832 				 graph_obj.list) {
833 		/*
834 		 * Unlink the interface, but don't free it here; the
835 		 * module which created it is responsible for freeing
836 		 * it
837 		 */
838 		__media_remove_intf_links(intf);
839 		media_gobj_destroy(&intf->graph_obj);
840 	}
841 
842 	mutex_unlock(&mdev->graph_mutex);
843 
844 	dev_dbg(mdev->dev, "Media device unregistered\n");
845 
846 	device_remove_file(&mdev->devnode->dev, &dev_attr_model);
847 	media_devnode_unregister(mdev->devnode);
848 	/* devnode free is handled in media_devnode_*() */
849 	mdev->devnode = NULL;
850 }
851 EXPORT_SYMBOL_GPL(media_device_unregister);
852 
853 #if IS_ENABLED(CONFIG_PCI)
854 void media_device_pci_init(struct media_device *mdev,
855 			   struct pci_dev *pci_dev,
856 			   const char *name)
857 {
858 	mdev->dev = &pci_dev->dev;
859 
860 	if (name)
861 		strscpy(mdev->model, name, sizeof(mdev->model));
862 	else
863 		strscpy(mdev->model, pci_name(pci_dev), sizeof(mdev->model));
864 
865 	sprintf(mdev->bus_info, "PCI:%s", pci_name(pci_dev));
866 
867 	mdev->hw_revision = (pci_dev->subsystem_vendor << 16)
868 			    | pci_dev->subsystem_device;
869 
870 	media_device_init(mdev);
871 }
872 EXPORT_SYMBOL_GPL(media_device_pci_init);
873 #endif
874 
875 #if IS_ENABLED(CONFIG_USB)
876 void __media_device_usb_init(struct media_device *mdev,
877 			     struct usb_device *udev,
878 			     const char *board_name,
879 			     const char *driver_name)
880 {
881 	mdev->dev = &udev->dev;
882 
883 	if (driver_name)
884 		strscpy(mdev->driver_name, driver_name,
885 			sizeof(mdev->driver_name));
886 
887 	if (board_name)
888 		strscpy(mdev->model, board_name, sizeof(mdev->model));
889 	else if (udev->product)
890 		strscpy(mdev->model, udev->product, sizeof(mdev->model));
891 	else
892 		strscpy(mdev->model, "unknown model", sizeof(mdev->model));
893 	if (udev->serial)
894 		strscpy(mdev->serial, udev->serial, sizeof(mdev->serial));
895 	usb_make_path(udev, mdev->bus_info, sizeof(mdev->bus_info));
896 	mdev->hw_revision = le16_to_cpu(udev->descriptor.bcdDevice);
897 
898 	media_device_init(mdev);
899 }
900 EXPORT_SYMBOL_GPL(__media_device_usb_init);
901 #endif
902 
903 
904 #endif /* CONFIG_MEDIA_CONTROLLER */
905