[mirror_ubuntu-jammy-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/videodev2.h>
#include <media/v4l2-device.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);
	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))
		v4l2_warn(v4l2_dev, "Non-NULL drvdata on register\n");
	dev_set_drvdata(dev, v4l2_dev);
	return 0;
}
EXPORT_SYMBOL_GPL(v4l2_device_register);

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

	if (v4l2_dev == NULL)
		return;
	if (v4l2_dev->dev)
		dev_set_drvdata(v4l2_dev->dev, NULL);
	/* Unregister subdevs */
	list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list)
		v4l2_device_unregister_subdev(sd);

	v4l2_dev->dev = NULL;
}
EXPORT_SYMBOL_GPL(v4l2_device_unregister);

int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
						struct v4l2_subdev *sd)
{
	/* 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;
	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);

void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)
{
	/* return if it isn't registered */
	if (sd == NULL || sd->v4l2_dev == NULL)
		return;
	spin_lock(&sd->v4l2_dev->lock);
	list_del(&sd->list);
	spin_unlock(&sd->v4l2_dev->lock);
	sd->v4l2_dev = NULL;
	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>
	24	#include <linux/videodev2.h>
	25	#include <media/v4l2-device.h>
	26
	27	int v4l2_device_register(struct device dev, struct v4l2_device v4l2_dev)
	28	{
3a63e449	29	if (v4l2_dev == NULL)
2a1fcdf0	30	return -EINVAL;
3a63e449	31
2a1fcdf0 HV	32	INIT_LIST_HEAD(&v4l2_dev->subdevs);
	33	spin_lock_init(&v4l2_dev->lock);
	34	v4l2_dev->dev = dev;
3a63e449 HV	35	if (dev == NULL) {
	36	/* If dev == NULL, then name must be filled in by the caller */
	37	WARN_ON(!v4l2_dev->name[0]);
	38	return 0;
	39	}
	40
	41	/* Set name to driver name + device name if it is empty. */
	42	if (!v4l2_dev->name[0])
	43	snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s",
c3ef01ce	44	dev->driver->name, dev_name(dev));
3a63e449 HV	45	if (dev_get_drvdata(dev))
3a63e449 HV	46	v4l2_warn(v4l2_dev, "Non-NULL drvdata on register\n");
2a1fcdf0 HV	47	dev_set_drvdata(dev, v4l2_dev);
	48	return 0;
	49	}
	50	EXPORT_SYMBOL_GPL(v4l2_device_register);
	51
	52	void v4l2_device_unregister(struct v4l2_device *v4l2_dev)
	53	{
	54	struct v4l2_subdev sd, next;
	55
3a63e449	56	if (v4l2_dev == NULL)
2a1fcdf0	57	return;
3a63e449 HV	58	if (v4l2_dev->dev)
	59	dev_set_drvdata(v4l2_dev->dev, NULL);
	60	/* Unregister subdevs */
2a1fcdf0 HV	61	list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list)
	62	v4l2_device_unregister_subdev(sd);
	63
	64	v4l2_dev->dev = NULL;
	65	}
	66	EXPORT_SYMBOL_GPL(v4l2_device_unregister);
	67
3a63e449 HV	68	int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
3a63e449 HV	69	struct v4l2_subdev *sd)
2a1fcdf0 HV	70	{
2a1fcdf0 HV	71	/* Check for valid input */
3a63e449	72	if (v4l2_dev == NULL \|\| sd == NULL \|\| !sd->name[0])
2a1fcdf0 HV	73	return -EINVAL;
2a1fcdf0 HV	74	/* Warn if we apparently re-register a subdev */
b0167600	75	WARN_ON(sd->v4l2_dev != NULL);
2a1fcdf0 HV	76	if (!try_module_get(sd->owner))
2a1fcdf0 HV	77	return -ENODEV;
b0167600	78	sd->v4l2_dev = v4l2_dev;
3a63e449 HV	79	spin_lock(&v4l2_dev->lock);
	80	list_add_tail(&sd->list, &v4l2_dev->subdevs);
	81	spin_unlock(&v4l2_dev->lock);
2a1fcdf0 HV	82	return 0;
	83	}
	84	EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
	85
	86	void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)
	87	{
	88	/* return if it isn't registered */
b0167600	89	if (sd == NULL \|\| sd->v4l2_dev == NULL)
2a1fcdf0	90	return;
b0167600	91	spin_lock(&sd->v4l2_dev->lock);
2a1fcdf0	92	list_del(&sd->list);
b0167600 HV	93	spin_unlock(&sd->v4l2_dev->lock);
b0167600 HV	94	sd->v4l2_dev = NULL;
2a1fcdf0 HV	95	module_put(sd->owner);
	96	}
	97	EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);