4 Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl>
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.
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.
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
21 #include <linux/types.h>
22 #include <linux/ioctl.h>
23 #include <linux/module.h>
24 #include <linux/i2c.h>
25 #include <linux/slab.h>
26 #if defined(CONFIG_SPI)
27 #include <linux/spi/spi.h>
29 #include <linux/videodev2.h>
30 #include <media/v4l2-device.h>
31 #include <media/v4l2-ctrls.h>
33 int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev)
38 INIT_LIST_HEAD(&v4l2_dev->subdevs);
39 spin_lock_init(&v4l2_dev->lock);
40 mutex_init(&v4l2_dev->ioctl_lock);
41 v4l2_prio_init(&v4l2_dev->prio);
42 kref_init(&v4l2_dev->ref);
46 /* If dev == NULL, then name must be filled in by the caller */
47 if (WARN_ON(!v4l2_dev->name[0]))
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",
55 dev->driver->name, dev_name(dev));
56 if (!dev_get_drvdata(dev))
57 dev_set_drvdata(dev, v4l2_dev);
60 EXPORT_SYMBOL_GPL(v4l2_device_register);
62 static void v4l2_device_release(struct kref *ref)
64 struct v4l2_device *v4l2_dev =
65 container_of(ref, struct v4l2_device, ref);
67 if (v4l2_dev->release)
68 v4l2_dev->release(v4l2_dev);
71 int v4l2_device_put(struct v4l2_device *v4l2_dev)
73 return kref_put(&v4l2_dev->ref, v4l2_device_release);
75 EXPORT_SYMBOL_GPL(v4l2_device_put);
77 int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename,
80 int num = atomic_inc_return(instance) - 1;
81 int len = strlen(basename);
83 if (basename[len - 1] >= '0' && basename[len - 1] <= '9')
84 snprintf(v4l2_dev->name, sizeof(v4l2_dev->name),
85 "%s-%d", basename, num);
87 snprintf(v4l2_dev->name, sizeof(v4l2_dev->name),
88 "%s%d", basename, num);
91 EXPORT_SYMBOL_GPL(v4l2_device_set_name);
93 void v4l2_device_disconnect(struct v4l2_device *v4l2_dev)
95 if (v4l2_dev->dev == NULL)
98 if (dev_get_drvdata(v4l2_dev->dev) == v4l2_dev)
99 dev_set_drvdata(v4l2_dev->dev, NULL);
100 put_device(v4l2_dev->dev);
101 v4l2_dev->dev = NULL;
103 EXPORT_SYMBOL_GPL(v4l2_device_disconnect);
105 void v4l2_device_unregister(struct v4l2_device *v4l2_dev)
107 struct v4l2_subdev *sd, *next;
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])
113 v4l2_device_disconnect(v4l2_dev);
115 /* Unregister subdevs */
116 list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list) {
117 v4l2_device_unregister_subdev(sd);
118 #if IS_ENABLED(CONFIG_I2C)
119 if (sd->flags & V4L2_SUBDEV_FL_IS_I2C) {
120 struct i2c_client *client = v4l2_get_subdevdata(sd);
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. */
127 i2c_unregister_device(client);
131 #if defined(CONFIG_SPI)
132 if (sd->flags & V4L2_SUBDEV_FL_IS_SPI) {
133 struct spi_device *spi = v4l2_get_subdevdata(sd);
136 spi_unregister_device(spi);
141 /* Mark as unregistered, thus preventing duplicate unregistrations */
142 v4l2_dev->name[0] = '\0';
144 EXPORT_SYMBOL_GPL(v4l2_device_unregister);
146 int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
147 struct v4l2_subdev *sd)
149 #if defined(CONFIG_MEDIA_CONTROLLER)
150 struct media_entity *entity = &sd->entity;
154 /* Check for valid input */
155 if (v4l2_dev == NULL || sd == NULL || !sd->name[0])
158 /* Warn if we apparently re-register a subdev */
159 WARN_ON(sd->v4l2_dev != NULL);
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.
168 sd->owner_v4l2_dev = v4l2_dev->dev && v4l2_dev->dev->driver &&
169 sd->owner == v4l2_dev->dev->driver->owner;
171 if (!sd->owner_v4l2_dev && !try_module_get(sd->owner))
174 sd->v4l2_dev = v4l2_dev;
175 if (sd->internal_ops && sd->internal_ops->registered) {
176 err = sd->internal_ops->registered(sd);
181 /* This just returns 0 if either of the two args is NULL */
182 err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler, NULL);
184 goto error_unregister;
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);
191 goto error_unregister;
195 spin_lock(&v4l2_dev->lock);
196 list_add_tail(&sd->list, &v4l2_dev->subdevs);
197 spin_unlock(&v4l2_dev->lock);
202 if (sd->internal_ops && sd->internal_ops->unregistered)
203 sd->internal_ops->unregistered(sd);
205 if (!sd->owner_v4l2_dev)
206 module_put(sd->owner);
210 EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
212 static void v4l2_device_release_subdev_node(struct video_device *vdev)
214 struct v4l2_subdev *sd = video_get_drvdata(vdev);
219 int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
221 struct video_device *vdev;
222 struct v4l2_subdev *sd;
225 /* Register a device node for every subdev marked with the
226 * V4L2_SUBDEV_FL_HAS_DEVNODE flag.
228 list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
229 if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE))
232 vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
238 video_set_drvdata(vdev, sd);
239 strlcpy(vdev->name, sd->name, sizeof(vdev->name));
240 vdev->v4l2_dev = v4l2_dev;
241 vdev->fops = &v4l2_subdev_fops;
242 vdev->release = v4l2_device_release_subdev_node;
243 vdev->ctrl_handler = sd->ctrl_handler;
244 err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1,
250 #if defined(CONFIG_MEDIA_CONTROLLER)
251 sd->entity.info.v4l.major = VIDEO_MAJOR;
252 sd->entity.info.v4l.minor = vdev->minor;
259 list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
262 video_unregister_device(sd->devnode);
267 EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes);
269 void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)
271 struct v4l2_device *v4l2_dev;
273 /* return if it isn't registered */
274 if (sd == NULL || sd->v4l2_dev == NULL)
277 v4l2_dev = sd->v4l2_dev;
279 spin_lock(&v4l2_dev->lock);
281 spin_unlock(&v4l2_dev->lock);
283 if (sd->internal_ops && sd->internal_ops->unregistered)
284 sd->internal_ops->unregistered(sd);
287 #if defined(CONFIG_MEDIA_CONTROLLER)
288 if (v4l2_dev->mdev) {
289 media_entity_remove_links(&sd->entity);
290 media_device_unregister_entity(&sd->entity);
293 video_unregister_device(sd->devnode);
294 if (!sd->owner_v4l2_dev)
295 module_put(sd->owner);
297 EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);