[deliverable/linux.git] / drivers / media / v4l2-core / v4l2-device.c

/*
    V4L2 device support.

    Copyright (C) 2008  Hans Verkuil <hverkuil@xs4all.nl>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    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/types.h>
#include <linux/ioctl.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#if defined(CONFIG_SPI)
#include <linux/spi/spi.h>
#endif
#include <linux/videodev2.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ctrls.h>

int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev)
{
	if (v4l2_dev == NULL)
		return -EINVAL;

	INIT_LIST_HEAD(&v4l2_dev->subdevs);
	spin_lock_init(&v4l2_dev->lock);
	mutex_init(&v4l2_dev->ioctl_lock);
	v4l2_prio_init(&v4l2_dev->prio);
	kref_init(&v4l2_dev->ref);
	get_device(dev);
	v4l2_dev->dev = dev;
	if (dev == NULL) {
		/* If dev == NULL, then name must be filled in by the caller */
		if (WARN_ON(!v4l2_dev->name[0]))
			return -EINVAL;
		return 0;
	}

	/* Set name to driver name + device name if it is empty. */
	if (!v4l2_dev->name[0])
		snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s",
			dev->driver->name, dev_name(dev));
	if (!dev_get_drvdata(dev))
		dev_set_drvdata(dev, v4l2_dev);
	return 0;
}
EXPORT_SYMBOL_GPL(v4l2_device_register);

static void v4l2_device_release(struct kref *ref)
{
	struct v4l2_device *v4l2_dev =
		container_of(ref, struct v4l2_device, ref);

	if (v4l2_dev->release)
		v4l2_dev->release(v4l2_dev);
}

int v4l2_device_put(struct v4l2_device *v4l2_dev)
{
	return kref_put(&v4l2_dev->ref, v4l2_device_release);
}
EXPORT_SYMBOL_GPL(v4l2_device_put);

int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename,
						atomic_t *instance)
{
	int num = atomic_inc_return(instance) - 1;
	int len = strlen(basename);

	if (basename[len - 1] >= '0' && basename[len - 1] <= '9')
		snprintf(v4l2_dev->name, sizeof(v4l2_dev->name),
				"%s-%d", basename, num);
	else
		snprintf(v4l2_dev->name, sizeof(v4l2_dev->name),
				"%s%d", basename, num);
	return num;
}
EXPORT_SYMBOL_GPL(v4l2_device_set_name);

void v4l2_device_disconnect(struct v4l2_device *v4l2_dev)
{
	if (v4l2_dev->dev == NULL)
		return;

	if (dev_get_drvdata(v4l2_dev->dev) == v4l2_dev)
		dev_set_drvdata(v4l2_dev->dev, NULL);
	put_device(v4l2_dev->dev);
	v4l2_dev->dev = NULL;
}
EXPORT_SYMBOL_GPL(v4l2_device_disconnect);

void v4l2_device_unregister(struct v4l2_device *v4l2_dev)
{
	struct v4l2_subdev *sd, *next;

	/* Just return if v4l2_dev is NULL or if it was already
	 * unregistered before. */
	if (v4l2_dev == NULL || !v4l2_dev->name[0])
		return;
	v4l2_device_disconnect(v4l2_dev);

	/* Unregister subdevs */
	list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list) {
		v4l2_device_unregister_subdev(sd);
#if IS_ENABLED(CONFIG_I2C)
		if (sd->flags & V4L2_SUBDEV_FL_IS_I2C) {
			struct i2c_client *client = v4l2_get_subdevdata(sd);

			/* We need to unregister the i2c client explicitly.
			   We cannot rely on i2c_del_adapter to always
			   unregister clients for us, since if the i2c bus
			   is a platform bus, then it is never deleted. */
			if (client)
				i2c_unregister_device(client);
			continue;
		}
#endif
#if defined(CONFIG_SPI)
		if (sd->flags & V4L2_SUBDEV_FL_IS_SPI) {
			struct spi_device *spi = v4l2_get_subdevdata(sd);

			if (spi)
				spi_unregister_device(spi);
			continue;
		}
#endif
	}
	/* Mark as unregistered, thus preventing duplicate unregistrations */
	v4l2_dev->name[0] = '\0';
}
EXPORT_SYMBOL_GPL(v4l2_device_unregister);

int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
				struct v4l2_subdev *sd)
{
#if defined(CONFIG_MEDIA_CONTROLLER)
	struct media_entity *entity = &sd->entity;
#endif
	int err;

	/* Check for valid input */
	if (v4l2_dev == NULL || sd == NULL || !sd->name[0])
		return -EINVAL;

	/* Warn if we apparently re-register a subdev */
	WARN_ON(sd->v4l2_dev != NULL);

	/*
	 * The reason to acquire the module here is to avoid unloading
	 * a module of sub-device which is registered to a media
	 * device. To make it possible to unload modules for media
	 * devices that also register sub-devices, do not
	 * try_module_get() such sub-device owners.
	 */
	sd->owner_v4l2_dev = v4l2_dev->dev && v4l2_dev->dev->driver &&
		sd->owner == v4l2_dev->dev->driver->owner;

	if (!sd->owner_v4l2_dev && !try_module_get(sd->owner))
		return -ENODEV;

	sd->v4l2_dev = v4l2_dev;
	if (sd->internal_ops && sd->internal_ops->registered) {
		err = sd->internal_ops->registered(sd);
		if (err)
			goto error_module;
	}

	/* This just returns 0 if either of the two args is NULL */
	err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler, NULL);
	if (err)
		goto error_unregister;

#if defined(CONFIG_MEDIA_CONTROLLER)
	/* Register the entity. */
	if (v4l2_dev->mdev) {
		err = media_device_register_entity(v4l2_dev->mdev, entity);
		if (err < 0)
			goto error_unregister;
	}
#endif

	spin_lock(&v4l2_dev->lock);
	list_add_tail(&sd->list, &v4l2_dev->subdevs);
	spin_unlock(&v4l2_dev->lock);

	return 0;

error_unregister:
	if (sd->internal_ops && sd->internal_ops->unregistered)
		sd->internal_ops->unregistered(sd);
error_module:
	if (!sd->owner_v4l2_dev)
		module_put(sd->owner);
	sd->v4l2_dev = NULL;
	return err;
}
EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);

static void v4l2_device_release_subdev_node(struct video_device *vdev)
{
	struct v4l2_subdev *sd = video_get_drvdata(vdev);
	sd->devnode = NULL;
	kfree(vdev);
}

int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
{
	struct video_device *vdev;
	struct v4l2_subdev *sd;
	int err;

	/* Register a device node for every subdev marked with the
	 * V4L2_SUBDEV_FL_HAS_DEVNODE flag.
	 */
	list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
		if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE))
			continue;

		vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
		if (!vdev) {
			err = -ENOMEM;
			goto clean_up;
		}

		video_set_drvdata(vdev, sd);
		strlcpy(vdev->name, sd->name, sizeof(vdev->name));
		vdev->v4l2_dev = v4l2_dev;
		vdev->fops = &v4l2_subdev_fops;
		vdev->release = v4l2_device_release_subdev_node;
		vdev->ctrl_handler = sd->ctrl_handler;
		err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1,
					      sd->owner);
		if (err < 0) {
			kfree(vdev);
			goto clean_up;
		}
#if defined(CONFIG_MEDIA_CONTROLLER)
		sd->entity.info.v4l.major = VIDEO_MAJOR;
		sd->entity.info.v4l.minor = vdev->minor;
#endif
		sd->devnode = vdev;
	}
	return 0;

clean_up:
	list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
		if (!sd->devnode)
			break;
		video_unregister_device(sd->devnode);
	}

	return err;
}
EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes);

void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)
{
	struct v4l2_device *v4l2_dev;

	/* return if it isn't registered */
	if (sd == NULL || sd->v4l2_dev == NULL)
		return;

	v4l2_dev = sd->v4l2_dev;

	spin_lock(&v4l2_dev->lock);
	list_del(&sd->list);
	spin_unlock(&v4l2_dev->lock);

	if (sd->internal_ops && sd->internal_ops->unregistered)
		sd->internal_ops->unregistered(sd);
	sd->v4l2_dev = NULL;

#if defined(CONFIG_MEDIA_CONTROLLER)
	if (v4l2_dev->mdev) {
		media_entity_remove_links(&sd->entity);
		media_device_unregister_entity(&sd->entity);
	}
#endif
	video_unregister_device(sd->devnode);
	if (!sd->owner_v4l2_dev)
		module_put(sd->owner);
}
EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);
Commit	Line	Data
2a1fcdf0 HV	1	/*
	2	V4L2 device support.
	3
	4	Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl>
	5
	6	This program is free software; you can redistribute it and/or modify
	7	it under the terms of the GNU General Public License as published by
	8	the Free Software Foundation; either version 2 of the License, or
	9	(at your option) any later version.
	10
	11	This program is distributed in the hope that it will be useful,
	12	but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	GNU General Public License for more details.
	15
	16	You should have received a copy of the GNU General Public License
	17	along with this program; if not, write to the Free Software
	18	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	19	*/
	20
	21	#include <linux/types.h>
	22	#include <linux/ioctl.h>
7a707b89	23	#include <linux/module.h>
2a1fcdf0	24	#include <linux/i2c.h>
3e0ec41c	25	#include <linux/slab.h>
85e09219 DB	26	#if defined(CONFIG_SPI)
	27	#include <linux/spi/spi.h>
	28	#endif
2a1fcdf0 HV	29	#include <linux/videodev2.h>
2a1fcdf0 HV	30	#include <media/v4l2-device.h>
11bbc1ca	31	#include <media/v4l2-ctrls.h>
2a1fcdf0 HV	32
	33	int v4l2_device_register(struct device dev, struct v4l2_device v4l2_dev)
	34	{
3a63e449	35	if (v4l2_dev == NULL)
2a1fcdf0	36	return -EINVAL;
3a63e449	37
2a1fcdf0 HV	38	INIT_LIST_HEAD(&v4l2_dev->subdevs);
2a1fcdf0 HV	39	spin_lock_init(&v4l2_dev->lock);
879aa24d	40	mutex_init(&v4l2_dev->ioctl_lock);
0f62fd6a	41	v4l2_prio_init(&v4l2_dev->prio);
bedf8bcf	42	kref_init(&v4l2_dev->ref);
236c5441	43	get_device(dev);
2a1fcdf0	44	v4l2_dev->dev = dev;
3a63e449 HV	45	if (dev == NULL) {
3a63e449 HV	46	/* If dev == NULL, then name must be filled in by the caller */
9e882e3b HV	47	if (WARN_ON(!v4l2_dev->name[0]))
9e882e3b HV	48	return -EINVAL;
3a63e449 HV	49	return 0;
	50	}
	51
	52	/* Set name to driver name + device name if it is empty. */
	53	if (!v4l2_dev->name[0])
	54	snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s",
c3ef01ce	55	dev->driver->name, dev_name(dev));
95db3a60 LP	56	if (!dev_get_drvdata(dev))
95db3a60 LP	57	dev_set_drvdata(dev, v4l2_dev);
2a1fcdf0 HV	58	return 0;
	59	}
	60	EXPORT_SYMBOL_GPL(v4l2_device_register);
	61
bedf8bcf HV	62	static void v4l2_device_release(struct kref *ref)
	63	{
	64	struct v4l2_device *v4l2_dev =
	65	container_of(ref, struct v4l2_device, ref);
	66
	67	if (v4l2_dev->release)
	68	v4l2_dev->release(v4l2_dev);
	69	}
	70
	71	int v4l2_device_put(struct v4l2_device *v4l2_dev)
	72	{
	73	return kref_put(&v4l2_dev->ref, v4l2_device_release);
	74	}
	75	EXPORT_SYMBOL_GPL(v4l2_device_put);
	76
102e7813 HV	77	int v4l2_device_set_name(struct v4l2_device v4l2_dev, const char basename,
	78	atomic_t *instance)
	79	{
	80	int num = atomic_inc_return(instance) - 1;
	81	int len = strlen(basename);
	82
	83	if (basename[len - 1] >= '0' && basename[len - 1] <= '9')
	84	snprintf(v4l2_dev->name, sizeof(v4l2_dev->name),
	85	"%s-%d", basename, num);
	86	else
	87	snprintf(v4l2_dev->name, sizeof(v4l2_dev->name),
	88	"%s%d", basename, num);
	89	return num;
	90	}
	91	EXPORT_SYMBOL_GPL(v4l2_device_set_name);
	92
ae6cfaac HV	93	void v4l2_device_disconnect(struct v4l2_device *v4l2_dev)
ae6cfaac HV	94	{
95db3a60 LP	95	if (v4l2_dev->dev == NULL)
	96	return;
	97
	98	if (dev_get_drvdata(v4l2_dev->dev) == v4l2_dev)
ae6cfaac	99	dev_set_drvdata(v4l2_dev->dev, NULL);
236c5441	100	put_device(v4l2_dev->dev);
95db3a60	101	v4l2_dev->dev = NULL;
ae6cfaac HV	102	}
	103	EXPORT_SYMBOL_GPL(v4l2_device_disconnect);
	104
2a1fcdf0 HV	105	void v4l2_device_unregister(struct v4l2_device *v4l2_dev)
	106	{
	107	struct v4l2_subdev sd, next;
	108
9e882e3b HV	109	/* Just return if v4l2_dev is NULL or if it was already
	110	* unregistered before. */
	111	if (v4l2_dev == NULL \|\| !v4l2_dev->name[0])
2a1fcdf0	112	return;
ae6cfaac HV	113	v4l2_device_disconnect(v4l2_dev);
ae6cfaac HV	114
3a63e449	115	/* Unregister subdevs */
b5b2b7ed	116	list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list) {
2a1fcdf0	117	v4l2_device_unregister_subdev(sd);
7b34be71	118	#if IS_ENABLED(CONFIG_I2C)
b5b2b7ed HV	119	if (sd->flags & V4L2_SUBDEV_FL_IS_I2C) {
	120	struct i2c_client *client = v4l2_get_subdevdata(sd);
	121
	122	/* We need to unregister the i2c client explicitly.
	123	We cannot rely on i2c_del_adapter to always
	124	unregister clients for us, since if the i2c bus
	125	is a platform bus, then it is never deleted. */
	126	if (client)
	127	i2c_unregister_device(client);
672dcd54	128	continue;
b5b2b7ed	129	}
85e09219 DB	130	#endif
	131	#if defined(CONFIG_SPI)
	132	if (sd->flags & V4L2_SUBDEV_FL_IS_SPI) {
	133	struct spi_device *spi = v4l2_get_subdevdata(sd);
	134
	135	if (spi)
	136	spi_unregister_device(spi);
672dcd54	137	continue;
85e09219	138	}
b7fd6067	139	#endif
b5b2b7ed	140	}
9e882e3b HV	141	/* Mark as unregistered, thus preventing duplicate unregistrations */
9e882e3b HV	142	v4l2_dev->name[0] = '\0';
2a1fcdf0 HV	143	}
	144	EXPORT_SYMBOL_GPL(v4l2_device_unregister);
	145
3a63e449	146	int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
61f5db54	147	struct v4l2_subdev *sd)
2a1fcdf0	148	{
61f5db54 LP	149	#if defined(CONFIG_MEDIA_CONTROLLER)
	150	struct media_entity *entity = &sd->entity;
	151	#endif
11bbc1ca HV	152	int err;
11bbc1ca HV	153
2a1fcdf0	154	/* Check for valid input */
3a63e449	155	if (v4l2_dev == NULL \|\| sd == NULL \|\| !sd->name[0])
2a1fcdf0	156	return -EINVAL;
2096a5dc	157
2a1fcdf0	158	/* Warn if we apparently re-register a subdev */
b0167600	159	WARN_ON(sd->v4l2_dev != NULL);
2096a5dc	160
b2a06aec SA	161	/*
	162	* The reason to acquire the module here is to avoid unloading
	163	* a module of sub-device which is registered to a media
	164	* device. To make it possible to unload modules for media
	165	* devices that also register sub-devices, do not
	166	* try_module_get() such sub-device owners.
	167	*/
	168	sd->owner_v4l2_dev = v4l2_dev->dev && v4l2_dev->dev->driver &&
	169	sd->owner == v4l2_dev->dev->driver->owner;
	170
	171	if (!sd->owner_v4l2_dev && !try_module_get(sd->owner))
2a1fcdf0	172	return -ENODEV;
2096a5dc	173
45f6f84a HV	174	sd->v4l2_dev = v4l2_dev;
	175	if (sd->internal_ops && sd->internal_ops->registered) {
	176	err = sd->internal_ops->registered(sd);
317efce9 LP	177	if (err)
317efce9 LP	178	goto error_module;
45f6f84a	179	}
2096a5dc	180
11bbc1ca	181	/* This just returns 0 if either of the two args is NULL */
34a6b7d0	182	err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler, NULL);
317efce9 LP	183	if (err)
317efce9 LP	184	goto error_unregister;
2096a5dc	185
61f5db54 LP	186	#if defined(CONFIG_MEDIA_CONTROLLER)
	187	/* Register the entity. */
	188	if (v4l2_dev->mdev) {
	189	err = media_device_register_entity(v4l2_dev->mdev, entity);
317efce9 LP	190	if (err < 0)
317efce9 LP	191	goto error_unregister;
61f5db54 LP	192	}
	193	#endif
	194
3a63e449 HV	195	spin_lock(&v4l2_dev->lock);
	196	list_add_tail(&sd->list, &v4l2_dev->subdevs);
	197	spin_unlock(&v4l2_dev->lock);
2096a5dc	198
2a1fcdf0	199	return 0;
317efce9 LP	200
	201	error_unregister:
	202	if (sd->internal_ops && sd->internal_ops->unregistered)
	203	sd->internal_ops->unregistered(sd);
	204	error_module:
b2a06aec SA	205	if (!sd->owner_v4l2_dev)
b2a06aec SA	206	module_put(sd->owner);
317efce9 LP	207	sd->v4l2_dev = NULL;
317efce9 LP	208	return err;
2a1fcdf0 HV	209	}
	210	EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
	211
3e0ec41c GL	212	static void v4l2_device_release_subdev_node(struct video_device *vdev)
	213	{
	214	struct v4l2_subdev *sd = video_get_drvdata(vdev);
	215	sd->devnode = NULL;
	216	kfree(vdev);
	217	}
	218
2096a5dc LP	219	int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
	220	{
	221	struct video_device *vdev;
	222	struct v4l2_subdev *sd;
	223	int err;
	224
	225	/* Register a device node for every subdev marked with the
	226	* V4L2_SUBDEV_FL_HAS_DEVNODE flag.
	227	*/
	228	list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
	229	if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE))
	230	continue;
	231
3e0ec41c GL	232	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
	233	if (!vdev) {
	234	err = -ENOMEM;
	235	goto clean_up;
	236	}
	237
	238	video_set_drvdata(vdev, sd);
2096a5dc LP	239	strlcpy(vdev->name, sd->name, sizeof(vdev->name));
	240	vdev->v4l2_dev = v4l2_dev;
	241	vdev->fops = &v4l2_subdev_fops;
3e0ec41c	242	vdev->release = v4l2_device_release_subdev_node;
18d171ba	243	vdev->ctrl_handler = sd->ctrl_handler;
2096a5dc LP	244	err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1,
2096a5dc LP	245	sd->owner);
3e0ec41c GL	246	if (err < 0) {
	247	kfree(vdev);
	248	goto clean_up;
	249	}
61f5db54	250	#if defined(CONFIG_MEDIA_CONTROLLER)
fa5034c6 CL	251	sd->entity.info.v4l.major = VIDEO_MAJOR;
fa5034c6 CL	252	sd->entity.info.v4l.minor = vdev->minor;
61f5db54	253	#endif
3e0ec41c	254	sd->devnode = vdev;
2096a5dc	255	}
2096a5dc	256	return 0;
3e0ec41c GL	257
	258	clean_up:
	259	list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
	260	if (!sd->devnode)
	261	break;
	262	video_unregister_device(sd->devnode);
	263	}
	264
	265	return err;
2096a5dc LP	266	}
	267	EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes);
	268
2a1fcdf0 HV	269	void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)
2a1fcdf0 HV	270	{
61f5db54 LP	271	struct v4l2_device *v4l2_dev;
61f5db54 LP	272
2a1fcdf0	273	/* return if it isn't registered */
b0167600	274	if (sd == NULL \|\| sd->v4l2_dev == NULL)
2a1fcdf0	275	return;
2096a5dc	276
61f5db54 LP	277	v4l2_dev = sd->v4l2_dev;
	278
	279	spin_lock(&v4l2_dev->lock);
2a1fcdf0	280	list_del(&sd->list);
61f5db54 LP	281	spin_unlock(&v4l2_dev->lock);
61f5db54 LP	282
45f6f84a HV	283	if (sd->internal_ops && sd->internal_ops->unregistered)
45f6f84a HV	284	sd->internal_ops->unregistered(sd);
b0167600	285	sd->v4l2_dev = NULL;
2096a5dc	286
61f5db54	287	#if defined(CONFIG_MEDIA_CONTROLLER)
c2efd3e6 SN	288	if (v4l2_dev->mdev) {
c2efd3e6 SN	289	media_entity_remove_links(&sd->entity);
61f5db54	290	media_device_unregister_entity(&sd->entity);
c2efd3e6	291	}
61f5db54	292	#endif
3e0ec41c	293	video_unregister_device(sd->devnode);
b2a06aec SA	294	if (!sd->owner_v4l2_dev)
b2a06aec SA	295	module_put(sd->owner);
2a1fcdf0 HV	296	}
2a1fcdf0 HV	297	EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);