xref: /linux/drivers/media/mc/mc-device.c (revision 24b10e5f8e0d2bee1a10fc67011ea5d936c1a389)
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 	int *alloc_fd = arg;
376 
377 	if (!mdev->ops || !mdev->ops->req_validate || !mdev->ops->req_queue)
378 		return -ENOTTY;
379 
380 	return media_request_alloc(mdev, alloc_fd);
381 }
382 
383 static long copy_arg_from_user(void *karg, void __user *uarg, unsigned int cmd)
384 {
385 	if ((_IOC_DIR(cmd) & _IOC_WRITE) &&
386 	    copy_from_user(karg, uarg, _IOC_SIZE(cmd)))
387 		return -EFAULT;
388 
389 	return 0;
390 }
391 
392 static long copy_arg_to_user(void __user *uarg, void *karg, unsigned int cmd)
393 {
394 	if ((_IOC_DIR(cmd) & _IOC_READ) &&
395 	    copy_to_user(uarg, karg, _IOC_SIZE(cmd)))
396 		return -EFAULT;
397 
398 	return 0;
399 }
400 
401 /* Do acquire the graph mutex */
402 #define MEDIA_IOC_FL_GRAPH_MUTEX	BIT(0)
403 
404 #define MEDIA_IOC_ARG(__cmd, func, fl, from_user, to_user)		\
405 	[_IOC_NR(MEDIA_IOC_##__cmd)] = {				\
406 		.cmd = MEDIA_IOC_##__cmd,				\
407 		.fn = func,						\
408 		.flags = fl,						\
409 		.arg_from_user = from_user,				\
410 		.arg_to_user = to_user,					\
411 	}
412 
413 #define MEDIA_IOC(__cmd, func, fl)					\
414 	MEDIA_IOC_ARG(__cmd, func, fl, copy_arg_from_user, copy_arg_to_user)
415 
416 /* the table is indexed by _IOC_NR(cmd) */
417 struct media_ioctl_info {
418 	unsigned int cmd;
419 	unsigned short flags;
420 	long (*fn)(struct media_device *dev, void *arg);
421 	long (*arg_from_user)(void *karg, void __user *uarg, unsigned int cmd);
422 	long (*arg_to_user)(void __user *uarg, void *karg, unsigned int cmd);
423 };
424 
425 static const struct media_ioctl_info ioctl_info[] = {
426 	MEDIA_IOC(DEVICE_INFO, media_device_get_info, MEDIA_IOC_FL_GRAPH_MUTEX),
427 	MEDIA_IOC(ENUM_ENTITIES, media_device_enum_entities, MEDIA_IOC_FL_GRAPH_MUTEX),
428 	MEDIA_IOC(ENUM_LINKS, media_device_enum_links, MEDIA_IOC_FL_GRAPH_MUTEX),
429 	MEDIA_IOC(SETUP_LINK, media_device_setup_link, MEDIA_IOC_FL_GRAPH_MUTEX),
430 	MEDIA_IOC(G_TOPOLOGY, media_device_get_topology, MEDIA_IOC_FL_GRAPH_MUTEX),
431 	MEDIA_IOC(REQUEST_ALLOC, media_device_request_alloc, 0),
432 };
433 
434 static long media_device_ioctl(struct file *filp, unsigned int cmd,
435 			       unsigned long __arg)
436 {
437 	struct media_devnode *devnode = media_devnode_data(filp);
438 	struct media_device *dev = devnode->media_dev;
439 	const struct media_ioctl_info *info;
440 	void __user *arg = (void __user *)__arg;
441 	char __karg[256], *karg = __karg;
442 	long ret;
443 
444 	if (_IOC_NR(cmd) >= ARRAY_SIZE(ioctl_info)
445 	    || ioctl_info[_IOC_NR(cmd)].cmd != cmd)
446 		return -ENOIOCTLCMD;
447 
448 	info = &ioctl_info[_IOC_NR(cmd)];
449 
450 	if (_IOC_SIZE(info->cmd) > sizeof(__karg)) {
451 		karg = kmalloc(_IOC_SIZE(info->cmd), GFP_KERNEL);
452 		if (!karg)
453 			return -ENOMEM;
454 	}
455 
456 	if (info->arg_from_user) {
457 		ret = info->arg_from_user(karg, arg, cmd);
458 		if (ret)
459 			goto out_free;
460 	}
461 
462 	if (info->flags & MEDIA_IOC_FL_GRAPH_MUTEX)
463 		mutex_lock(&dev->graph_mutex);
464 
465 	ret = info->fn(dev, karg);
466 
467 	if (info->flags & MEDIA_IOC_FL_GRAPH_MUTEX)
468 		mutex_unlock(&dev->graph_mutex);
469 
470 	if (!ret && info->arg_to_user)
471 		ret = info->arg_to_user(arg, karg, cmd);
472 
473 out_free:
474 	if (karg != __karg)
475 		kfree(karg);
476 
477 	return ret;
478 }
479 
480 #ifdef CONFIG_COMPAT
481 
482 struct media_links_enum32 {
483 	__u32 entity;
484 	compat_uptr_t pads; /* struct media_pad_desc * */
485 	compat_uptr_t links; /* struct media_link_desc * */
486 	__u32 reserved[4];
487 };
488 
489 static long media_device_enum_links32(struct media_device *mdev,
490 				      struct media_links_enum32 __user *ulinks)
491 {
492 	struct media_links_enum links;
493 	compat_uptr_t pads_ptr, links_ptr;
494 	int ret;
495 
496 	memset(&links, 0, sizeof(links));
497 
498 	if (get_user(links.entity, &ulinks->entity)
499 	    || get_user(pads_ptr, &ulinks->pads)
500 	    || get_user(links_ptr, &ulinks->links))
501 		return -EFAULT;
502 
503 	links.pads = compat_ptr(pads_ptr);
504 	links.links = compat_ptr(links_ptr);
505 
506 	ret = media_device_enum_links(mdev, &links);
507 	if (ret)
508 		return ret;
509 
510 	if (copy_to_user(ulinks->reserved, links.reserved,
511 			 sizeof(ulinks->reserved)))
512 		return -EFAULT;
513 	return 0;
514 }
515 
516 #define MEDIA_IOC_ENUM_LINKS32		_IOWR('|', 0x02, struct media_links_enum32)
517 
518 static long media_device_compat_ioctl(struct file *filp, unsigned int cmd,
519 				      unsigned long arg)
520 {
521 	struct media_devnode *devnode = media_devnode_data(filp);
522 	struct media_device *dev = devnode->media_dev;
523 	long ret;
524 
525 	switch (cmd) {
526 	case MEDIA_IOC_ENUM_LINKS32:
527 		mutex_lock(&dev->graph_mutex);
528 		ret = media_device_enum_links32(dev,
529 				(struct media_links_enum32 __user *)arg);
530 		mutex_unlock(&dev->graph_mutex);
531 		break;
532 
533 	default:
534 		return media_device_ioctl(filp, cmd, arg);
535 	}
536 
537 	return ret;
538 }
539 #endif /* CONFIG_COMPAT */
540 
541 static const struct media_file_operations media_device_fops = {
542 	.owner = THIS_MODULE,
543 	.open = media_device_open,
544 	.ioctl = media_device_ioctl,
545 #ifdef CONFIG_COMPAT
546 	.compat_ioctl = media_device_compat_ioctl,
547 #endif /* CONFIG_COMPAT */
548 	.release = media_device_close,
549 };
550 
551 /* -----------------------------------------------------------------------------
552  * sysfs
553  */
554 
555 static ssize_t model_show(struct device *cd,
556 			  struct device_attribute *attr, char *buf)
557 {
558 	struct media_devnode *devnode = to_media_devnode(cd);
559 	struct media_device *mdev = devnode->media_dev;
560 
561 	return sprintf(buf, "%.*s\n", (int)sizeof(mdev->model), mdev->model);
562 }
563 
564 static DEVICE_ATTR_RO(model);
565 
566 /* -----------------------------------------------------------------------------
567  * Registration/unregistration
568  */
569 
570 static void media_device_release(struct media_devnode *devnode)
571 {
572 	dev_dbg(devnode->parent, "Media device released\n");
573 }
574 
575 static void __media_device_unregister_entity(struct media_entity *entity)
576 {
577 	struct media_device *mdev = entity->graph_obj.mdev;
578 	struct media_link *link, *tmp;
579 	struct media_interface *intf;
580 	struct media_pad *iter;
581 
582 	ida_free(&mdev->entity_internal_idx, entity->internal_idx);
583 
584 	/* Remove all interface links pointing to this entity */
585 	list_for_each_entry(intf, &mdev->interfaces, graph_obj.list) {
586 		list_for_each_entry_safe(link, tmp, &intf->links, list) {
587 			if (link->entity == entity)
588 				__media_remove_intf_link(link);
589 		}
590 	}
591 
592 	/* Remove all data links that belong to this entity */
593 	__media_entity_remove_links(entity);
594 
595 	/* Remove all pads that belong to this entity */
596 	media_entity_for_each_pad(entity, iter)
597 		media_gobj_destroy(&iter->graph_obj);
598 
599 	/* Remove the entity */
600 	media_gobj_destroy(&entity->graph_obj);
601 
602 	/* invoke entity_notify callbacks to handle entity removal?? */
603 }
604 
605 int __must_check media_device_register_entity(struct media_device *mdev,
606 					      struct media_entity *entity)
607 {
608 	struct media_entity_notify *notify, *next;
609 	struct media_pad *iter;
610 	int ret;
611 
612 	if (entity->function == MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN ||
613 	    entity->function == MEDIA_ENT_F_UNKNOWN)
614 		dev_warn(mdev->dev,
615 			 "Entity type for entity %s was not initialized!\n",
616 			 entity->name);
617 
618 	/* Warn if we apparently re-register an entity */
619 	WARN_ON(entity->graph_obj.mdev != NULL);
620 	entity->graph_obj.mdev = mdev;
621 	INIT_LIST_HEAD(&entity->links);
622 	entity->num_links = 0;
623 	entity->num_backlinks = 0;
624 
625 	ret = ida_alloc_min(&mdev->entity_internal_idx, 1, GFP_KERNEL);
626 	if (ret < 0)
627 		return ret;
628 	entity->internal_idx = ret;
629 
630 	mutex_lock(&mdev->graph_mutex);
631 	mdev->entity_internal_idx_max =
632 		max(mdev->entity_internal_idx_max, entity->internal_idx);
633 
634 	/* Initialize media_gobj embedded at the entity */
635 	media_gobj_create(mdev, MEDIA_GRAPH_ENTITY, &entity->graph_obj);
636 
637 	/* Initialize objects at the pads */
638 	media_entity_for_each_pad(entity, iter)
639 		media_gobj_create(mdev, MEDIA_GRAPH_PAD, &iter->graph_obj);
640 
641 	/* invoke entity_notify callbacks */
642 	list_for_each_entry_safe(notify, next, &mdev->entity_notify, list)
643 		notify->notify(entity, notify->notify_data);
644 
645 	if (mdev->entity_internal_idx_max
646 	    >= mdev->pm_count_walk.ent_enum.idx_max) {
647 		struct media_graph new = { .top = 0 };
648 
649 		/*
650 		 * Initialise the new graph walk before cleaning up
651 		 * the old one in order not to spoil the graph walk
652 		 * object of the media device if graph walk init fails.
653 		 */
654 		ret = media_graph_walk_init(&new, mdev);
655 		if (ret) {
656 			__media_device_unregister_entity(entity);
657 			mutex_unlock(&mdev->graph_mutex);
658 			return ret;
659 		}
660 		media_graph_walk_cleanup(&mdev->pm_count_walk);
661 		mdev->pm_count_walk = new;
662 	}
663 	mutex_unlock(&mdev->graph_mutex);
664 
665 	return 0;
666 }
667 EXPORT_SYMBOL_GPL(media_device_register_entity);
668 
669 void media_device_unregister_entity(struct media_entity *entity)
670 {
671 	struct media_device *mdev = entity->graph_obj.mdev;
672 
673 	if (mdev == NULL)
674 		return;
675 
676 	mutex_lock(&mdev->graph_mutex);
677 	__media_device_unregister_entity(entity);
678 	mutex_unlock(&mdev->graph_mutex);
679 }
680 EXPORT_SYMBOL_GPL(media_device_unregister_entity);
681 
682 void media_device_init(struct media_device *mdev)
683 {
684 	INIT_LIST_HEAD(&mdev->entities);
685 	INIT_LIST_HEAD(&mdev->interfaces);
686 	INIT_LIST_HEAD(&mdev->pads);
687 	INIT_LIST_HEAD(&mdev->links);
688 	INIT_LIST_HEAD(&mdev->entity_notify);
689 
690 	mutex_init(&mdev->req_queue_mutex);
691 	mutex_init(&mdev->graph_mutex);
692 	ida_init(&mdev->entity_internal_idx);
693 
694 	atomic_set(&mdev->request_id, 0);
695 
696 	if (!*mdev->bus_info)
697 		media_set_bus_info(mdev->bus_info, sizeof(mdev->bus_info),
698 				   mdev->dev);
699 
700 	dev_dbg(mdev->dev, "Media device initialized\n");
701 }
702 EXPORT_SYMBOL_GPL(media_device_init);
703 
704 void media_device_cleanup(struct media_device *mdev)
705 {
706 	ida_destroy(&mdev->entity_internal_idx);
707 	mdev->entity_internal_idx_max = 0;
708 	media_graph_walk_cleanup(&mdev->pm_count_walk);
709 	mutex_destroy(&mdev->graph_mutex);
710 	mutex_destroy(&mdev->req_queue_mutex);
711 }
712 EXPORT_SYMBOL_GPL(media_device_cleanup);
713 
714 int __must_check __media_device_register(struct media_device *mdev,
715 					 struct module *owner)
716 {
717 	struct media_devnode *devnode;
718 	int ret;
719 
720 	devnode = kzalloc(sizeof(*devnode), GFP_KERNEL);
721 	if (!devnode)
722 		return -ENOMEM;
723 
724 	/* Register the device node. */
725 	mdev->devnode = devnode;
726 	devnode->fops = &media_device_fops;
727 	devnode->parent = mdev->dev;
728 	devnode->release = media_device_release;
729 
730 	/* Set version 0 to indicate user-space that the graph is static */
731 	mdev->topology_version = 0;
732 
733 	ret = media_devnode_register(mdev, devnode, owner);
734 	if (ret < 0) {
735 		/* devnode free is handled in media_devnode_*() */
736 		mdev->devnode = NULL;
737 		return ret;
738 	}
739 
740 	ret = device_create_file(&devnode->dev, &dev_attr_model);
741 	if (ret < 0) {
742 		/* devnode free is handled in media_devnode_*() */
743 		mdev->devnode = NULL;
744 		media_devnode_unregister_prepare(devnode);
745 		media_devnode_unregister(devnode);
746 		return ret;
747 	}
748 
749 	dev_dbg(mdev->dev, "Media device registered\n");
750 
751 	return 0;
752 }
753 EXPORT_SYMBOL_GPL(__media_device_register);
754 
755 void media_device_register_entity_notify(struct media_device *mdev,
756 					struct media_entity_notify *nptr)
757 {
758 	mutex_lock(&mdev->graph_mutex);
759 	list_add_tail(&nptr->list, &mdev->entity_notify);
760 	mutex_unlock(&mdev->graph_mutex);
761 }
762 EXPORT_SYMBOL_GPL(media_device_register_entity_notify);
763 
764 /*
765  * Note: Should be called with mdev->lock held.
766  */
767 static void __media_device_unregister_entity_notify(struct media_device *mdev,
768 					struct media_entity_notify *nptr)
769 {
770 	list_del(&nptr->list);
771 }
772 
773 void media_device_unregister_entity_notify(struct media_device *mdev,
774 					struct media_entity_notify *nptr)
775 {
776 	mutex_lock(&mdev->graph_mutex);
777 	__media_device_unregister_entity_notify(mdev, nptr);
778 	mutex_unlock(&mdev->graph_mutex);
779 }
780 EXPORT_SYMBOL_GPL(media_device_unregister_entity_notify);
781 
782 void media_device_unregister(struct media_device *mdev)
783 {
784 	struct media_entity *entity;
785 	struct media_entity *next;
786 	struct media_interface *intf, *tmp_intf;
787 	struct media_entity_notify *notify, *nextp;
788 
789 	if (mdev == NULL)
790 		return;
791 
792 	mutex_lock(&mdev->graph_mutex);
793 
794 	/* Check if mdev was ever registered at all */
795 	if (!media_devnode_is_registered(mdev->devnode)) {
796 		mutex_unlock(&mdev->graph_mutex);
797 		return;
798 	}
799 
800 	/* Clear the devnode register bit to avoid races with media dev open */
801 	media_devnode_unregister_prepare(mdev->devnode);
802 
803 	/* Remove all entities from the media device */
804 	list_for_each_entry_safe(entity, next, &mdev->entities, graph_obj.list)
805 		__media_device_unregister_entity(entity);
806 
807 	/* Remove all entity_notify callbacks from the media device */
808 	list_for_each_entry_safe(notify, nextp, &mdev->entity_notify, list)
809 		__media_device_unregister_entity_notify(mdev, notify);
810 
811 	/* Remove all interfaces from the media device */
812 	list_for_each_entry_safe(intf, tmp_intf, &mdev->interfaces,
813 				 graph_obj.list) {
814 		/*
815 		 * Unlink the interface, but don't free it here; the
816 		 * module which created it is responsible for freeing
817 		 * it
818 		 */
819 		__media_remove_intf_links(intf);
820 		media_gobj_destroy(&intf->graph_obj);
821 	}
822 
823 	mutex_unlock(&mdev->graph_mutex);
824 
825 	dev_dbg(mdev->dev, "Media device unregistered\n");
826 
827 	device_remove_file(&mdev->devnode->dev, &dev_attr_model);
828 	media_devnode_unregister(mdev->devnode);
829 	/* devnode free is handled in media_devnode_*() */
830 	mdev->devnode = NULL;
831 }
832 EXPORT_SYMBOL_GPL(media_device_unregister);
833 
834 #if IS_ENABLED(CONFIG_PCI)
835 void media_device_pci_init(struct media_device *mdev,
836 			   struct pci_dev *pci_dev,
837 			   const char *name)
838 {
839 	mdev->dev = &pci_dev->dev;
840 
841 	if (name)
842 		strscpy(mdev->model, name, sizeof(mdev->model));
843 	else
844 		strscpy(mdev->model, pci_name(pci_dev), sizeof(mdev->model));
845 
846 	sprintf(mdev->bus_info, "PCI:%s", pci_name(pci_dev));
847 
848 	mdev->hw_revision = (pci_dev->subsystem_vendor << 16)
849 			    | pci_dev->subsystem_device;
850 
851 	media_device_init(mdev);
852 }
853 EXPORT_SYMBOL_GPL(media_device_pci_init);
854 #endif
855 
856 #if IS_ENABLED(CONFIG_USB)
857 void __media_device_usb_init(struct media_device *mdev,
858 			     struct usb_device *udev,
859 			     const char *board_name,
860 			     const char *driver_name)
861 {
862 	mdev->dev = &udev->dev;
863 
864 	if (driver_name)
865 		strscpy(mdev->driver_name, driver_name,
866 			sizeof(mdev->driver_name));
867 
868 	if (board_name)
869 		strscpy(mdev->model, board_name, sizeof(mdev->model));
870 	else if (udev->product)
871 		strscpy(mdev->model, udev->product, sizeof(mdev->model));
872 	else
873 		strscpy(mdev->model, "unknown model", sizeof(mdev->model));
874 	if (udev->serial)
875 		strscpy(mdev->serial, udev->serial, sizeof(mdev->serial));
876 	usb_make_path(udev, mdev->bus_info, sizeof(mdev->bus_info));
877 	mdev->hw_revision = le16_to_cpu(udev->descriptor.bcdDevice);
878 
879 	media_device_init(mdev);
880 }
881 EXPORT_SYMBOL_GPL(__media_device_usb_init);
882 #endif
883 
884 
885 #endif /* CONFIG_MEDIA_CONTROLLER */
886