/* 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);