diff options
Diffstat (limited to 'drivers/media/video/v4l2-device.c')
| -rw-r--r-- | drivers/media/video/v4l2-device.c | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/drivers/media/video/v4l2-device.c b/drivers/media/video/v4l2-device.c new file mode 100644 index 00000000000..9eefde03159 --- /dev/null +++ b/drivers/media/video/v4l2-device.c @@ -0,0 +1,86 @@ +/* + 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 (dev == NULL || v4l2_dev == NULL) + return -EINVAL; + /* Warn if we apparently re-register a device */ + WARN_ON(dev_get_drvdata(dev)); + INIT_LIST_HEAD(&v4l2_dev->subdevs); + spin_lock_init(&v4l2_dev->lock); + v4l2_dev->dev = dev; + snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s", + dev->driver->name, dev->bus_id); + 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 || v4l2_dev->dev == NULL) + return; + 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 *dev, struct v4l2_subdev *sd) +{ + /* Check for valid input */ + if (dev == NULL || sd == NULL || !sd->name[0]) + return -EINVAL; + /* Warn if we apparently re-register a subdev */ + WARN_ON(sd->dev); + if (!try_module_get(sd->owner)) + return -ENODEV; + sd->dev = dev; + spin_lock(&dev->lock); + list_add_tail(&sd->list, &dev->subdevs); + spin_unlock(&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->dev == NULL) + return; + spin_lock(&sd->dev->lock); + list_del(&sd->list); + spin_unlock(&sd->dev->lock); + sd->dev = NULL; + module_put(sd->owner); +} +EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev); |