[mirror_ubuntu-bionic-kernel.git] / drivers / media / media-device.c

/*
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/compat.h>
#include <linux/export.h>
#include <linux/ioctl.h>
#include <linux/media.h>
#include <linux/types.h>

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

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

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

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

static int media_device_get_info(struct media_device *dev,
				 struct media_device_info __user *__info)
{
	struct media_device_info info;

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

	strlcpy(info.driver, dev->dev->driver->name, sizeof(info.driver));
	strlcpy(info.model, dev->model, sizeof(info.model));
	strlcpy(info.serial, dev->serial, sizeof(info.serial));
	strlcpy(info.bus_info, dev->bus_info, sizeof(info.bus_info));

	info.media_version = MEDIA_API_VERSION;
	info.hw_revision = dev->hw_revision;
	info.driver_version = dev->driver_version;

	if (copy_to_user(__info, &info, sizeof(*__info)))
		return -EFAULT;
	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;

	spin_lock(&mdev->lock);

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

	spin_unlock(&mdev->lock);

	return NULL;
}

static long media_device_enum_entities(struct media_device *mdev,
				       struct media_entity_desc __user *uent)
{
	struct media_entity *ent;
	struct media_entity_desc u_ent;

	if (copy_from_user(&u_ent.id, &uent->id, sizeof(u_ent.id)))
		return -EFAULT;

	ent = find_entity(mdev, u_ent.id);

	if (ent == NULL)
		return -EINVAL;

	u_ent.id = ent->id;
	if (ent->name) {
		strncpy(u_ent.name, ent->name, sizeof(u_ent.name));
		u_ent.name[sizeof(u_ent.name) - 1] = '\0';
	} else {
		memset(u_ent.name, 0, sizeof(u_ent.name));
	}
	u_ent.type = ent->type;
	u_ent.revision = ent->revision;
	u_ent.flags = ent->flags;
	u_ent.group_id = ent->group_id;
	u_ent.pads = ent->num_pads;
	u_ent.links = ent->num_links - ent->num_backlinks;
	memcpy(&u_ent.raw, &ent->info, sizeof(ent->info));
	if (copy_to_user(uent, &u_ent, sizeof(u_ent)))
		return -EFAULT;
	return 0;
}

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

static long __media_device_enum_links(struct media_device *mdev,
				      struct media_links_enum *links)
{
	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_desc __user *ulink;
		unsigned int l;

		for (l = 0, ulink = links->links; l < entity->num_links; l++) {
			struct media_link_desc link;

			/* Ignore backlinks. */
			if (entity->links[l].source->entity != entity)
				continue;

			memset(&link, 0, sizeof(link));
			media_device_kpad_to_upad(entity->links[l].source,
						  &link.source);
			media_device_kpad_to_upad(entity->links[l].sink,
						  &link.sink);
			link.flags = entity->links[l].flags;
			if (copy_to_user(ulink, &link, sizeof(*ulink)))
				return -EFAULT;
			ulink++;
		}
	}

	return 0;
}

static long media_device_enum_links(struct media_device *mdev,
				    struct media_links_enum __user *ulinks)
{
	struct media_links_enum links;
	int rval;

	if (copy_from_user(&links, ulinks, sizeof(links)))
		return -EFAULT;

	rval = __media_device_enum_links(mdev, &links);
	if (rval < 0)
		return rval;

	if (copy_to_user(ulinks, &links, sizeof(*ulinks)))
		return -EFAULT;

	return 0;
}

static long media_device_setup_link(struct media_device *mdev,
				    struct media_link_desc __user *_ulink)
{
	struct media_link *link = NULL;
	struct media_link_desc ulink;
	struct media_entity *source;
	struct media_entity *sink;
	int ret;

	if (copy_from_user(&ulink, _ulink, sizeof(ulink)))
		return -EFAULT;

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

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

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

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

	/* Setup the link on both entities. */
	ret = __media_entity_setup_link(link, ulink.flags);

	if (copy_to_user(_ulink, &ulink, sizeof(ulink)))
		return -EFAULT;

	return ret;
}

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 = to_media_device(devnode);
	long ret;

	switch (cmd) {
	case MEDIA_IOC_DEVICE_INFO:
		ret = media_device_get_info(dev,
				(struct media_device_info __user *)arg);
		break;

	case MEDIA_IOC_ENUM_ENTITIES:
		ret = media_device_enum_entities(dev,
				(struct media_entity_desc __user *)arg);
		break;

	case MEDIA_IOC_ENUM_LINKS:
		mutex_lock(&dev->graph_mutex);
		ret = media_device_enum_links(dev,
				(struct media_links_enum __user *)arg);
		mutex_unlock(&dev->graph_mutex);
		break;

	case MEDIA_IOC_SETUP_LINK:
		mutex_lock(&dev->graph_mutex);
		ret = media_device_setup_link(dev,
				(struct media_link_desc __user *)arg);
		mutex_unlock(&dev->graph_mutex);
		break;

	default:
		ret = -ENOIOCTLCMD;
	}

	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 = to_media_device(devnode);
	long ret;

	switch (cmd) {
	case MEDIA_IOC_DEVICE_INFO:
	case MEDIA_IOC_ENUM_ENTITIES:
	case MEDIA_IOC_SETUP_LINK:
		return media_device_ioctl(filp, cmd, arg);

	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:
		ret = -ENOIOCTLCMD;
	}

	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_device *mdev = to_media_device(to_media_devnode(cd));

	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 *mdev)
{
}

/**
 * media_device_register - register 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
 */
int __must_check media_device_register(struct media_device *mdev)
{
	int ret;

	if (WARN_ON(mdev->dev == NULL || mdev->model[0] == 0))
		return -EINVAL;

	mdev->entity_id = 1;
	INIT_LIST_HEAD(&mdev->entities);
	spin_lock_init(&mdev->lock);
	mutex_init(&mdev->graph_mutex);

	/* Register the device node. */
	mdev->devnode.fops = &media_device_fops;
	mdev->devnode.parent = mdev->dev;
	mdev->devnode.release = media_device_release;
	ret = media_devnode_register(&mdev->devnode);
	if (ret < 0)
		return ret;

	ret = device_create_file(&mdev->devnode.dev, &dev_attr_model);
	if (ret < 0) {
		media_devnode_unregister(&mdev->devnode);
		return ret;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(media_device_register);

/**
 * media_device_unregister - unregister a media device
 * @mdev:	The media device
 *
 */
void media_device_unregister(struct media_device *mdev)
{
	struct media_entity *entity;
	struct media_entity *next;

	list_for_each_entry_safe(entity, next, &mdev->entities, list)
		media_device_unregister_entity(entity);

	device_remove_file(&mdev->devnode.dev, &dev_attr_model);
	media_devnode_unregister(&mdev->devnode);
}
EXPORT_SYMBOL_GPL(media_device_unregister);

/**
 * 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)
{
	/* Warn if we apparently re-register an entity */
	WARN_ON(entity->parent != NULL);
	entity->parent = mdev;

	spin_lock(&mdev->lock);
	if (entity->id == 0)
		entity->id = mdev->entity_id++;
	else
		mdev->entity_id = max(entity->id + 1, mdev->entity_id);
	list_add_tail(&entity->list, &mdev->entities);
	spin_unlock(&mdev->lock);

	return 0;
}
EXPORT_SYMBOL_GPL(media_device_register_entity);

/**
 * media_device_unregister_entity - Unregister an entity
 * @entity:	The entity
 *
 * If the entity has never been registered this function will return
 * immediately.
 */
void media_device_unregister_entity(struct media_entity *entity)
{
	struct media_device *mdev = entity->parent;

	if (mdev == NULL)
		return;

	spin_lock(&mdev->lock);
	list_del(&entity->list);
	spin_unlock(&mdev->lock);
	entity->parent = NULL;
}
EXPORT_SYMBOL_GPL(media_device_unregister_entity);
Commit	Line	Data
176fb0d1 LP	1	/*
	2	* Media device
	3	*
	4	* Copyright (C) 2010 Nokia Corporation
	5	*
	6	* Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
	7	* Sakari Ailus <sakari.ailus@iki.fi>
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License version 2 as
	11	* published by the Free Software Foundation.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	21	*/
	22
b0a1f2a8 SA	23	#include <linux/compat.h>
b0a1f2a8 SA	24	#include <linux/export.h>
176fb0d1	25	#include <linux/ioctl.h>
140d8816	26	#include <linux/media.h>
b0a1f2a8	27	#include <linux/types.h>
176fb0d1 LP	28
	29	#include <media/media-device.h>
	30	#include <media/media-devnode.h>
53e269c1	31	#include <media/media-entity.h>
176fb0d1	32
140d8816 LP	33	/* -----------------------------------------------------------------------------
	34	* Userspace API
	35	*/
	36
	37	static int media_device_open(struct file *filp)
	38	{
	39	return 0;
	40	}
	41
	42	static int media_device_close(struct file *filp)
	43	{
	44	return 0;
	45	}
	46
	47	static int media_device_get_info(struct media_device *dev,
	48	struct media_device_info __user *__info)
	49	{
	50	struct media_device_info info;
	51
	52	memset(&info, 0, sizeof(info));
	53
	54	strlcpy(info.driver, dev->dev->driver->name, sizeof(info.driver));
	55	strlcpy(info.model, dev->model, sizeof(info.model));
	56	strlcpy(info.serial, dev->serial, sizeof(info.serial));
	57	strlcpy(info.bus_info, dev->bus_info, sizeof(info.bus_info));
	58
	59	info.media_version = MEDIA_API_VERSION;
	60	info.hw_revision = dev->hw_revision;
	61	info.driver_version = dev->driver_version;
	62
b17d3945 NT	63	if (copy_to_user(__info, &info, sizeof(*__info)))
	64	return -EFAULT;
	65	return 0;
140d8816 LP	66	}
140d8816 LP	67
1651333b LP	68	static struct media_entity find_entity(struct media_device mdev, u32 id)
	69	{
	70	struct media_entity *entity;
	71	int next = id & MEDIA_ENT_ID_FLAG_NEXT;
	72
	73	id &= ~MEDIA_ENT_ID_FLAG_NEXT;
	74
	75	spin_lock(&mdev->lock);
	76
	77	media_device_for_each_entity(entity, mdev) {
	78	if ((entity->id == id && !next) \|\|
	79	(entity->id > id && next)) {
	80	spin_unlock(&mdev->lock);
	81	return entity;
	82	}
	83	}
	84
	85	spin_unlock(&mdev->lock);
	86
	87	return NULL;
	88	}
	89
	90	static long media_device_enum_entities(struct media_device *mdev,
	91	struct media_entity_desc __user *uent)
	92	{
	93	struct media_entity *ent;
	94	struct media_entity_desc u_ent;
	95
	96	if (copy_from_user(&u_ent.id, &uent->id, sizeof(u_ent.id)))
	97	return -EFAULT;
	98
	99	ent = find_entity(mdev, u_ent.id);
	100
	101	if (ent == NULL)
	102	return -EINVAL;
	103
	104	u_ent.id = ent->id;
c06ca8f9 DC	105	if (ent->name) {
	106	strncpy(u_ent.name, ent->name, sizeof(u_ent.name));
	107	u_ent.name[sizeof(u_ent.name) - 1] = '\0';
	108	} else {
	109	memset(u_ent.name, 0, sizeof(u_ent.name));
	110	}
1651333b LP	111	u_ent.type = ent->type;
	112	u_ent.revision = ent->revision;
	113	u_ent.flags = ent->flags;
	114	u_ent.group_id = ent->group_id;
	115	u_ent.pads = ent->num_pads;
	116	u_ent.links = ent->num_links - ent->num_backlinks;
fa5034c6	117	memcpy(&u_ent.raw, &ent->info, sizeof(ent->info));
1651333b LP	118	if (copy_to_user(uent, &u_ent, sizeof(u_ent)))
	119	return -EFAULT;
	120	return 0;
	121	}
	122
	123	static void media_device_kpad_to_upad(const struct media_pad *kpad,
	124	struct media_pad_desc *upad)
	125	{
	126	upad->entity = kpad->entity->id;
	127	upad->index = kpad->index;
	128	upad->flags = kpad->flags;
	129	}
	130
b0a1f2a8 SA	131	static long __media_device_enum_links(struct media_device *mdev,
b0a1f2a8 SA	132	struct media_links_enum *links)
1651333b LP	133	{
1651333b LP	134	struct media_entity *entity;
1651333b	135
b0a1f2a8	136	entity = find_entity(mdev, links->entity);
1651333b LP	137	if (entity == NULL)
	138	return -EINVAL;
	139
b0a1f2a8	140	if (links->pads) {
1651333b LP	141	unsigned int p;
	142
	143	for (p = 0; p < entity->num_pads; p++) {
	144	struct media_pad_desc pad;
c88e739b DC	145
c88e739b DC	146	memset(&pad, 0, sizeof(pad));
1651333b	147	media_device_kpad_to_upad(&entity->pads[p], &pad);
b0a1f2a8	148	if (copy_to_user(&links->pads[p], &pad, sizeof(pad)))
1651333b LP	149	return -EFAULT;
	150	}
	151	}
	152
b0a1f2a8	153	if (links->links) {
1651333b LP	154	struct media_link_desc __user *ulink;
	155	unsigned int l;
	156
b0a1f2a8	157	for (l = 0, ulink = links->links; l < entity->num_links; l++) {
1651333b LP	158	struct media_link_desc link;
	159
	160	/* Ignore backlinks. */
	161	if (entity->links[l].source->entity != entity)
	162	continue;
	163
c88e739b	164	memset(&link, 0, sizeof(link));
1651333b LP	165	media_device_kpad_to_upad(entity->links[l].source,
	166	&link.source);
	167	media_device_kpad_to_upad(entity->links[l].sink,
	168	&link.sink);
	169	link.flags = entity->links[l].flags;
	170	if (copy_to_user(ulink, &link, sizeof(*ulink)))
	171	return -EFAULT;
	172	ulink++;
	173	}
	174	}
b0a1f2a8 SA	175
	176	return 0;
	177	}
	178
	179	static long media_device_enum_links(struct media_device *mdev,
	180	struct media_links_enum __user *ulinks)
	181	{
	182	struct media_links_enum links;
	183	int rval;
	184
	185	if (copy_from_user(&links, ulinks, sizeof(links)))
	186	return -EFAULT;
	187
	188	rval = __media_device_enum_links(mdev, &links);
	189	if (rval < 0)
	190	return rval;
	191
1651333b LP	192	if (copy_to_user(ulinks, &links, sizeof(*ulinks)))
1651333b LP	193	return -EFAULT;
b0a1f2a8	194
1651333b LP	195	return 0;
	196	}
	197
97548ed4 LP	198	static long media_device_setup_link(struct media_device *mdev,
	199	struct media_link_desc __user *_ulink)
	200	{
	201	struct media_link *link = NULL;
	202	struct media_link_desc ulink;
	203	struct media_entity *source;
	204	struct media_entity *sink;
	205	int ret;
	206
	207	if (copy_from_user(&ulink, _ulink, sizeof(ulink)))
	208	return -EFAULT;
	209
	210	/* Find the source and sink entities and link.
	211	*/
	212	source = find_entity(mdev, ulink.source.entity);
	213	sink = find_entity(mdev, ulink.sink.entity);
	214
	215	if (source == NULL \|\| sink == NULL)
	216	return -EINVAL;
	217
	218	if (ulink.source.index >= source->num_pads \|\|
	219	ulink.sink.index >= sink->num_pads)
	220	return -EINVAL;
	221
	222	link = media_entity_find_link(&source->pads[ulink.source.index],
	223	&sink->pads[ulink.sink.index]);
	224	if (link == NULL)
	225	return -EINVAL;
	226
	227	/* Setup the link on both entities. */
	228	ret = __media_entity_setup_link(link, ulink.flags);
	229
	230	if (copy_to_user(_ulink, &ulink, sizeof(ulink)))
	231	return -EFAULT;
	232
	233	return ret;
	234	}
	235
140d8816 LP	236	static long media_device_ioctl(struct file *filp, unsigned int cmd,
	237	unsigned long arg)
	238	{
	239	struct media_devnode *devnode = media_devnode_data(filp);
	240	struct media_device *dev = to_media_device(devnode);
	241	long ret;
	242
	243	switch (cmd) {
	244	case MEDIA_IOC_DEVICE_INFO:
	245	ret = media_device_get_info(dev,
	246	(struct media_device_info __user *)arg);
	247	break;
	248
1651333b LP	249	case MEDIA_IOC_ENUM_ENTITIES:
	250	ret = media_device_enum_entities(dev,
	251	(struct media_entity_desc __user *)arg);
	252	break;
	253
	254	case MEDIA_IOC_ENUM_LINKS:
	255	mutex_lock(&dev->graph_mutex);
	256	ret = media_device_enum_links(dev,
	257	(struct media_links_enum __user *)arg);
	258	mutex_unlock(&dev->graph_mutex);
	259	break;
	260
97548ed4 LP	261	case MEDIA_IOC_SETUP_LINK:
	262	mutex_lock(&dev->graph_mutex);
	263	ret = media_device_setup_link(dev,
	264	(struct media_link_desc __user *)arg);
	265	mutex_unlock(&dev->graph_mutex);
	266	break;
	267
140d8816 LP	268	default:
	269	ret = -ENOIOCTLCMD;
	270	}
	271
	272	return ret;
	273	}
	274
b0a1f2a8 SA	275	#ifdef CONFIG_COMPAT
	276
	277	struct media_links_enum32 {
	278	__u32 entity;
	279	compat_uptr_t pads; /* struct media_pad_desc * */
	280	compat_uptr_t links; /* struct media_link_desc * */
	281	__u32 reserved[4];
	282	};
	283
	284	static long media_device_enum_links32(struct media_device *mdev,
	285	struct media_links_enum32 __user *ulinks)
	286	{
	287	struct media_links_enum links;
	288	compat_uptr_t pads_ptr, links_ptr;
	289
	290	memset(&links, 0, sizeof(links));
	291
	292	if (get_user(links.entity, &ulinks->entity)
	293	\|\| get_user(pads_ptr, &ulinks->pads)
	294	\|\| get_user(links_ptr, &ulinks->links))
	295	return -EFAULT;
	296
	297	links.pads = compat_ptr(pads_ptr);
	298	links.links = compat_ptr(links_ptr);
	299
	300	return __media_device_enum_links(mdev, &links);
	301	}
	302
	303	#define MEDIA_IOC_ENUM_LINKS32 _IOWR('\|', 0x02, struct media_links_enum32)
	304
	305	static long media_device_compat_ioctl(struct file *filp, unsigned int cmd,
	306	unsigned long arg)
	307	{
	308	struct media_devnode *devnode = media_devnode_data(filp);
	309	struct media_device *dev = to_media_device(devnode);
	310	long ret;
	311
	312	switch (cmd) {
	313	case MEDIA_IOC_DEVICE_INFO:
	314	case MEDIA_IOC_ENUM_ENTITIES:
	315	case MEDIA_IOC_SETUP_LINK:
	316	return media_device_ioctl(filp, cmd, arg);
	317
	318	case MEDIA_IOC_ENUM_LINKS32:
	319	mutex_lock(&dev->graph_mutex);
	320	ret = media_device_enum_links32(dev,
	321	(struct media_links_enum32 __user *)arg);
	322	mutex_unlock(&dev->graph_mutex);
	323	break;
	324
	325	default:
	326	ret = -ENOIOCTLCMD;
	327	}
	328
	329	return ret;
	330	}
	331	#endif /* CONFIG_COMPAT */
	332
176fb0d1 LP	333	static const struct media_file_operations media_device_fops = {
176fb0d1 LP	334	.owner = THIS_MODULE,
140d8816 LP	335	.open = media_device_open,
140d8816 LP	336	.ioctl = media_device_ioctl,
b0a1f2a8 SA	337	#ifdef CONFIG_COMPAT
	338	.compat_ioctl = media_device_compat_ioctl,
	339	#endif /* CONFIG_COMPAT */
140d8816	340	.release = media_device_close,
176fb0d1 LP	341	};
	342
	343	/* -----------------------------------------------------------------------------
	344	* sysfs
	345	*/
	346
	347	static ssize_t show_model(struct device *cd,
	348	struct device_attribute attr, char buf)
	349	{
	350	struct media_device *mdev = to_media_device(to_media_devnode(cd));
	351
	352	return sprintf(buf, "%.*s\n", (int)sizeof(mdev->model), mdev->model);
	353	}
	354
	355	static DEVICE_ATTR(model, S_IRUGO, show_model, NULL);
	356
	357	/* -----------------------------------------------------------------------------
	358	* Registration/unregistration
	359	*/
	360
	361	static void media_device_release(struct media_devnode *mdev)
	362	{
	363	}
	364
	365	/**
	366	* media_device_register - register a media device
	367	* @mdev: The media device
	368	*
	369	* The caller is responsible for initializing the media device before
	370	* registration. The following fields must be set:
	371	*
	372	* - dev must point to the parent device
	373	* - model must be filled with the device model name
	374	*/
	375	int __must_check media_device_register(struct media_device *mdev)
	376	{
	377	int ret;
	378
	379	if (WARN_ON(mdev->dev == NULL \|\| mdev->model[0] == 0))
	380	return -EINVAL;
	381
53e269c1 LP	382	mdev->entity_id = 1;
	383	INIT_LIST_HEAD(&mdev->entities);
	384	spin_lock_init(&mdev->lock);
503c3d82	385	mutex_init(&mdev->graph_mutex);
53e269c1	386
176fb0d1 LP	387	/* Register the device node. */
	388	mdev->devnode.fops = &media_device_fops;
	389	mdev->devnode.parent = mdev->dev;
	390	mdev->devnode.release = media_device_release;
	391	ret = media_devnode_register(&mdev->devnode);
	392	if (ret < 0)
	393	return ret;
	394
	395	ret = device_create_file(&mdev->devnode.dev, &dev_attr_model);
	396	if (ret < 0) {
	397	media_devnode_unregister(&mdev->devnode);
	398	return ret;
	399	}
	400
	401	return 0;
	402	}
	403	EXPORT_SYMBOL_GPL(media_device_register);
	404
	405	/**
	406	* media_device_unregister - unregister a media device
	407	* @mdev: The media device
	408	*
	409	*/
	410	void media_device_unregister(struct media_device *mdev)
	411	{
53e269c1 LP	412	struct media_entity *entity;
	413	struct media_entity *next;
	414
	415	list_for_each_entry_safe(entity, next, &mdev->entities, list)
	416	media_device_unregister_entity(entity);
	417
176fb0d1 LP	418	device_remove_file(&mdev->devnode.dev, &dev_attr_model);
	419	media_devnode_unregister(&mdev->devnode);
	420	}
	421	EXPORT_SYMBOL_GPL(media_device_unregister);
53e269c1 LP	422
	423	/**
	424	* media_device_register_entity - Register an entity with a media device
	425	* @mdev: The media device
	426	* @entity: The entity
	427	*/
	428	int __must_check media_device_register_entity(struct media_device *mdev,
	429	struct media_entity *entity)
	430	{
	431	/* Warn if we apparently re-register an entity */
	432	WARN_ON(entity->parent != NULL);
	433	entity->parent = mdev;
	434
	435	spin_lock(&mdev->lock);
	436	if (entity->id == 0)
	437	entity->id = mdev->entity_id++;
	438	else
	439	mdev->entity_id = max(entity->id + 1, mdev->entity_id);
	440	list_add_tail(&entity->list, &mdev->entities);
	441	spin_unlock(&mdev->lock);
	442
	443	return 0;
	444	}
	445	EXPORT_SYMBOL_GPL(media_device_register_entity);
	446
	447	/**
	448	* media_device_unregister_entity - Unregister an entity
	449	* @entity: The entity
	450	*
	451	* If the entity has never been registered this function will return
	452	* immediately.
	453	*/
	454	void media_device_unregister_entity(struct media_entity *entity)
	455	{
	456	struct media_device *mdev = entity->parent;
	457
	458	if (mdev == NULL)
	459	return;
	460
	461	spin_lock(&mdev->lock);
	462	list_del(&entity->list);
	463	spin_unlock(&mdev->lock);
	464	entity->parent = NULL;
	465	}
	466	EXPORT_SYMBOL_GPL(media_device_unregister_entity);