[mirror_ubuntu-bionic-kernel.git] / drivers / media / video / 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/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 */
		WARN_ON(!v4l2_dev->name[0]);
		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;

	if (v4l2_dev == NULL)
		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 defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))
		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
	}
}
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);

	if (!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) {
			module_put(sd->owner);
			return err;
		}
	}

	/* This just returns 0 if either of the two args is NULL */
	err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler);
	if (err) {
		if (sd->internal_ops && sd->internal_ops->unregistered)
			sd->internal_ops->unregistered(sd);
		module_put(sd->owner);
		return err;
	}

#if defined(CONFIG_MEDIA_CONTROLLER)
	/* Register the entity. */
	if (v4l2_dev->mdev) {
		err = media_device_register_entity(v4l2_dev->mdev, entity);
		if (err < 0) {
			if (sd->internal_ops && sd->internal_ops->unregistered)
				sd->internal_ops->unregistered(sd);
			module_put(sd->owner);
			return err;
		}
	}
#endif

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

	return 0;
}
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.v4l.major = VIDEO_MAJOR;
		sd->entity.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_device_unregister_entity(&sd->entity);
#endif
	video_unregister_device(sd->devnode);
	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>
	23	#include <linux/i2c.h>
3e0ec41c	24	#include <linux/slab.h>
85e09219 DB	25	#if defined(CONFIG_SPI)
	26	#include <linux/spi/spi.h>
	27	#endif
2a1fcdf0 HV	28	#include <linux/videodev2.h>
2a1fcdf0 HV	29	#include <media/v4l2-device.h>
11bbc1ca	30	#include <media/v4l2-ctrls.h>
2a1fcdf0 HV	31
	32	int v4l2_device_register(struct device dev, struct v4l2_device v4l2_dev)
	33	{
3a63e449	34	if (v4l2_dev == NULL)
2a1fcdf0	35	return -EINVAL;
3a63e449	36
2a1fcdf0 HV	37	INIT_LIST_HEAD(&v4l2_dev->subdevs);
2a1fcdf0 HV	38	spin_lock_init(&v4l2_dev->lock);
879aa24d	39	mutex_init(&v4l2_dev->ioctl_lock);
0f62fd6a	40	v4l2_prio_init(&v4l2_dev->prio);
bedf8bcf	41	kref_init(&v4l2_dev->ref);
236c5441	42	get_device(dev);
2a1fcdf0	43	v4l2_dev->dev = dev;
3a63e449 HV	44	if (dev == NULL) {
	45	/* If dev == NULL, then name must be filled in by the caller */
	46	WARN_ON(!v4l2_dev->name[0]);
	47	return 0;
	48	}
	49
	50	/* Set name to driver name + device name if it is empty. */
	51	if (!v4l2_dev->name[0])
	52	snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s",
c3ef01ce	53	dev->driver->name, dev_name(dev));
95db3a60 LP	54	if (!dev_get_drvdata(dev))
95db3a60 LP	55	dev_set_drvdata(dev, v4l2_dev);
2a1fcdf0 HV	56	return 0;
	57	}
	58	EXPORT_SYMBOL_GPL(v4l2_device_register);
	59
bedf8bcf HV	60	static void v4l2_device_release(struct kref *ref)
	61	{
	62	struct v4l2_device *v4l2_dev =
	63	container_of(ref, struct v4l2_device, ref);
	64
	65	if (v4l2_dev->release)
	66	v4l2_dev->release(v4l2_dev);
	67	}
	68
	69	int v4l2_device_put(struct v4l2_device *v4l2_dev)
	70	{
	71	return kref_put(&v4l2_dev->ref, v4l2_device_release);
	72	}
	73	EXPORT_SYMBOL_GPL(v4l2_device_put);
	74
102e7813 HV	75	int v4l2_device_set_name(struct v4l2_device v4l2_dev, const char basename,
	76	atomic_t *instance)
	77	{
	78	int num = atomic_inc_return(instance) - 1;
	79	int len = strlen(basename);
	80
	81	if (basename[len - 1] >= '0' && basename[len - 1] <= '9')
	82	snprintf(v4l2_dev->name, sizeof(v4l2_dev->name),
	83	"%s-%d", basename, num);
	84	else
	85	snprintf(v4l2_dev->name, sizeof(v4l2_dev->name),
	86	"%s%d", basename, num);
	87	return num;
	88	}
	89	EXPORT_SYMBOL_GPL(v4l2_device_set_name);
	90
ae6cfaac HV	91	void v4l2_device_disconnect(struct v4l2_device *v4l2_dev)
ae6cfaac HV	92	{
95db3a60 LP	93	if (v4l2_dev->dev == NULL)
	94	return;
	95
	96	if (dev_get_drvdata(v4l2_dev->dev) == v4l2_dev)
ae6cfaac	97	dev_set_drvdata(v4l2_dev->dev, NULL);
236c5441	98	put_device(v4l2_dev->dev);
95db3a60	99	v4l2_dev->dev = NULL;
ae6cfaac HV	100	}
	101	EXPORT_SYMBOL_GPL(v4l2_device_disconnect);
	102
2a1fcdf0 HV	103	void v4l2_device_unregister(struct v4l2_device *v4l2_dev)
	104	{
	105	struct v4l2_subdev sd, next;
	106
3a63e449	107	if (v4l2_dev == NULL)
2a1fcdf0	108	return;
ae6cfaac HV	109	v4l2_device_disconnect(v4l2_dev);
ae6cfaac HV	110
3a63e449	111	/* Unregister subdevs */
b5b2b7ed	112	list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list) {
2a1fcdf0	113	v4l2_device_unregister_subdev(sd);
ef5b5168	114	#if defined(CONFIG_I2C) \|\| (defined(CONFIG_I2C_MODULE) && defined(MODULE))
b5b2b7ed HV	115	if (sd->flags & V4L2_SUBDEV_FL_IS_I2C) {
	116	struct i2c_client *client = v4l2_get_subdevdata(sd);
	117
	118	/* We need to unregister the i2c client explicitly.
	119	We cannot rely on i2c_del_adapter to always
	120	unregister clients for us, since if the i2c bus
	121	is a platform bus, then it is never deleted. */
	122	if (client)
	123	i2c_unregister_device(client);
672dcd54	124	continue;
b5b2b7ed	125	}
85e09219 DB	126	#endif
	127	#if defined(CONFIG_SPI)
	128	if (sd->flags & V4L2_SUBDEV_FL_IS_SPI) {
	129	struct spi_device *spi = v4l2_get_subdevdata(sd);
	130
	131	if (spi)
	132	spi_unregister_device(spi);
672dcd54	133	continue;
85e09219	134	}
b7fd6067	135	#endif
b5b2b7ed	136	}
2a1fcdf0 HV	137	}
	138	EXPORT_SYMBOL_GPL(v4l2_device_unregister);
	139
3a63e449	140	int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
61f5db54	141	struct v4l2_subdev *sd)
2a1fcdf0	142	{
61f5db54 LP	143	#if defined(CONFIG_MEDIA_CONTROLLER)
	144	struct media_entity *entity = &sd->entity;
	145	#endif
11bbc1ca HV	146	int err;
11bbc1ca HV	147
2a1fcdf0	148	/* Check for valid input */
3a63e449	149	if (v4l2_dev == NULL \|\| sd == NULL \|\| !sd->name[0])
2a1fcdf0	150	return -EINVAL;
2096a5dc	151
2a1fcdf0	152	/* Warn if we apparently re-register a subdev */
b0167600	153	WARN_ON(sd->v4l2_dev != NULL);
2096a5dc	154
2a1fcdf0 HV	155	if (!try_module_get(sd->owner))
2a1fcdf0 HV	156	return -ENODEV;
2096a5dc	157
45f6f84a HV	158	sd->v4l2_dev = v4l2_dev;
	159	if (sd->internal_ops && sd->internal_ops->registered) {
	160	err = sd->internal_ops->registered(sd);
b7534f00 LP	161	if (err) {
b7534f00 LP	162	module_put(sd->owner);
45f6f84a	163	return err;
b7534f00	164	}
45f6f84a	165	}
2096a5dc	166
11bbc1ca HV	167	/* This just returns 0 if either of the two args is NULL */
11bbc1ca HV	168	err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler);
45f6f84a HV	169	if (err) {
	170	if (sd->internal_ops && sd->internal_ops->unregistered)
	171	sd->internal_ops->unregistered(sd);
b7534f00	172	module_put(sd->owner);
11bbc1ca	173	return err;
45f6f84a	174	}
2096a5dc	175
61f5db54 LP	176	#if defined(CONFIG_MEDIA_CONTROLLER)
	177	/* Register the entity. */
	178	if (v4l2_dev->mdev) {
	179	err = media_device_register_entity(v4l2_dev->mdev, entity);
	180	if (err < 0) {
	181	if (sd->internal_ops && sd->internal_ops->unregistered)
	182	sd->internal_ops->unregistered(sd);
	183	module_put(sd->owner);
	184	return err;
	185	}
	186	}
	187	#endif
	188
3a63e449 HV	189	spin_lock(&v4l2_dev->lock);
	190	list_add_tail(&sd->list, &v4l2_dev->subdevs);
	191	spin_unlock(&v4l2_dev->lock);
2096a5dc	192
2a1fcdf0 HV	193	return 0;
	194	}
	195	EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
	196
3e0ec41c GL	197	static void v4l2_device_release_subdev_node(struct video_device *vdev)
	198	{
	199	struct v4l2_subdev *sd = video_get_drvdata(vdev);
	200	sd->devnode = NULL;
	201	kfree(vdev);
	202	}
	203
2096a5dc LP	204	int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
	205	{
	206	struct video_device *vdev;
	207	struct v4l2_subdev *sd;
	208	int err;
	209
	210	/* Register a device node for every subdev marked with the
	211	* V4L2_SUBDEV_FL_HAS_DEVNODE flag.
	212	*/
	213	list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
	214	if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE))
	215	continue;
	216
3e0ec41c GL	217	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
	218	if (!vdev) {
	219	err = -ENOMEM;
	220	goto clean_up;
	221	}
	222
	223	video_set_drvdata(vdev, sd);
2096a5dc LP	224	strlcpy(vdev->name, sd->name, sizeof(vdev->name));
	225	vdev->v4l2_dev = v4l2_dev;
	226	vdev->fops = &v4l2_subdev_fops;
3e0ec41c	227	vdev->release = v4l2_device_release_subdev_node;
18d171ba	228	vdev->ctrl_handler = sd->ctrl_handler;
2096a5dc LP	229	err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1,
2096a5dc LP	230	sd->owner);
3e0ec41c GL	231	if (err < 0) {
	232	kfree(vdev);
	233	goto clean_up;
	234	}
61f5db54 LP	235	#if defined(CONFIG_MEDIA_CONTROLLER)
	236	sd->entity.v4l.major = VIDEO_MAJOR;
	237	sd->entity.v4l.minor = vdev->minor;
	238	#endif
3e0ec41c	239	sd->devnode = vdev;
2096a5dc	240	}
2096a5dc	241	return 0;
3e0ec41c GL	242
	243	clean_up:
	244	list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
	245	if (!sd->devnode)
	246	break;
	247	video_unregister_device(sd->devnode);
	248	}
	249
	250	return err;
2096a5dc LP	251	}
	252	EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes);
	253
2a1fcdf0 HV	254	void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)
2a1fcdf0 HV	255	{
61f5db54 LP	256	struct v4l2_device *v4l2_dev;
61f5db54 LP	257
2a1fcdf0	258	/* return if it isn't registered */
b0167600	259	if (sd == NULL \|\| sd->v4l2_dev == NULL)
2a1fcdf0	260	return;
2096a5dc	261
61f5db54 LP	262	v4l2_dev = sd->v4l2_dev;
	263
	264	spin_lock(&v4l2_dev->lock);
2a1fcdf0	265	list_del(&sd->list);
61f5db54 LP	266	spin_unlock(&v4l2_dev->lock);
61f5db54 LP	267
45f6f84a HV	268	if (sd->internal_ops && sd->internal_ops->unregistered)
45f6f84a HV	269	sd->internal_ops->unregistered(sd);
b0167600	270	sd->v4l2_dev = NULL;
2096a5dc	271
61f5db54 LP	272	#if defined(CONFIG_MEDIA_CONTROLLER)
	273	if (v4l2_dev->mdev)
	274	media_device_unregister_entity(&sd->entity);
	275	#endif
3e0ec41c	276	video_unregister_device(sd->devnode);
2a1fcdf0 HV	277	module_put(sd->owner);
	278	}
	279	EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);