Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab...
[linux-2.6.git] / drivers / media / video / v4l2-device.c
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/module.h>
24 #include <linux/i2c.h>
25 #include <linux/slab.h>
26 #if defined(CONFIG_SPI)
27 #include <linux/spi/spi.h>
28 #endif
29 #include <linux/videodev2.h>
30 #include <media/v4l2-device.h>
31 #include <media/v4l2-ctrls.h>
32
33 int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev)
34 {
35         if (v4l2_dev == NULL)
36                 return -EINVAL;
37
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);
43         get_device(dev);
44         v4l2_dev->dev = dev;
45         if (dev == NULL) {
46                 /* If dev == NULL, then name must be filled in by the caller */
47                 WARN_ON(!v4l2_dev->name[0]);
48                 return 0;
49         }
50
51         /* Set name to driver name + device name if it is empty. */
52         if (!v4l2_dev->name[0])
53                 snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s",
54                         dev->driver->name, dev_name(dev));
55         if (!dev_get_drvdata(dev))
56                 dev_set_drvdata(dev, v4l2_dev);
57         return 0;
58 }
59 EXPORT_SYMBOL_GPL(v4l2_device_register);
60
61 static void v4l2_device_release(struct kref *ref)
62 {
63         struct v4l2_device *v4l2_dev =
64                 container_of(ref, struct v4l2_device, ref);
65
66         if (v4l2_dev->release)
67                 v4l2_dev->release(v4l2_dev);
68 }
69
70 int v4l2_device_put(struct v4l2_device *v4l2_dev)
71 {
72         return kref_put(&v4l2_dev->ref, v4l2_device_release);
73 }
74 EXPORT_SYMBOL_GPL(v4l2_device_put);
75
76 int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename,
77                                                 atomic_t *instance)
78 {
79         int num = atomic_inc_return(instance) - 1;
80         int len = strlen(basename);
81
82         if (basename[len - 1] >= '0' && basename[len - 1] <= '9')
83                 snprintf(v4l2_dev->name, sizeof(v4l2_dev->name),
84                                 "%s-%d", basename, num);
85         else
86                 snprintf(v4l2_dev->name, sizeof(v4l2_dev->name),
87                                 "%s%d", basename, num);
88         return num;
89 }
90 EXPORT_SYMBOL_GPL(v4l2_device_set_name);
91
92 void v4l2_device_disconnect(struct v4l2_device *v4l2_dev)
93 {
94         if (v4l2_dev->dev == NULL)
95                 return;
96
97         if (dev_get_drvdata(v4l2_dev->dev) == v4l2_dev)
98                 dev_set_drvdata(v4l2_dev->dev, NULL);
99         put_device(v4l2_dev->dev);
100         v4l2_dev->dev = NULL;
101 }
102 EXPORT_SYMBOL_GPL(v4l2_device_disconnect);
103
104 void v4l2_device_unregister(struct v4l2_device *v4l2_dev)
105 {
106         struct v4l2_subdev *sd, *next;
107
108         if (v4l2_dev == NULL)
109                 return;
110         v4l2_device_disconnect(v4l2_dev);
111
112         /* Unregister subdevs */
113         list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list) {
114                 v4l2_device_unregister_subdev(sd);
115 #if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))
116                 if (sd->flags & V4L2_SUBDEV_FL_IS_I2C) {
117                         struct i2c_client *client = v4l2_get_subdevdata(sd);
118
119                         /* We need to unregister the i2c client explicitly.
120                            We cannot rely on i2c_del_adapter to always
121                            unregister clients for us, since if the i2c bus
122                            is a platform bus, then it is never deleted. */
123                         if (client)
124                                 i2c_unregister_device(client);
125                         continue;
126                 }
127 #endif
128 #if defined(CONFIG_SPI)
129                 if (sd->flags & V4L2_SUBDEV_FL_IS_SPI) {
130                         struct spi_device *spi = v4l2_get_subdevdata(sd);
131
132                         if (spi)
133                                 spi_unregister_device(spi);
134                         continue;
135                 }
136 #endif
137         }
138 }
139 EXPORT_SYMBOL_GPL(v4l2_device_unregister);
140
141 int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
142                                 struct v4l2_subdev *sd)
143 {
144 #if defined(CONFIG_MEDIA_CONTROLLER)
145         struct media_entity *entity = &sd->entity;
146 #endif
147         int err;
148
149         /* Check for valid input */
150         if (v4l2_dev == NULL || sd == NULL || !sd->name[0])
151                 return -EINVAL;
152
153         /* Warn if we apparently re-register a subdev */
154         WARN_ON(sd->v4l2_dev != NULL);
155
156         if (!try_module_get(sd->owner))
157                 return -ENODEV;
158
159         sd->v4l2_dev = v4l2_dev;
160         if (sd->internal_ops && sd->internal_ops->registered) {
161                 err = sd->internal_ops->registered(sd);
162                 if (err) {
163                         module_put(sd->owner);
164                         return err;
165                 }
166         }
167
168         /* This just returns 0 if either of the two args is NULL */
169         err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler);
170         if (err) {
171                 if (sd->internal_ops && sd->internal_ops->unregistered)
172                         sd->internal_ops->unregistered(sd);
173                 module_put(sd->owner);
174                 return err;
175         }
176
177 #if defined(CONFIG_MEDIA_CONTROLLER)
178         /* Register the entity. */
179         if (v4l2_dev->mdev) {
180                 err = media_device_register_entity(v4l2_dev->mdev, entity);
181                 if (err < 0) {
182                         if (sd->internal_ops && sd->internal_ops->unregistered)
183                                 sd->internal_ops->unregistered(sd);
184                         module_put(sd->owner);
185                         return err;
186                 }
187         }
188 #endif
189
190         spin_lock(&v4l2_dev->lock);
191         list_add_tail(&sd->list, &v4l2_dev->subdevs);
192         spin_unlock(&v4l2_dev->lock);
193
194         return 0;
195 }
196 EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
197
198 static void v4l2_device_release_subdev_node(struct video_device *vdev)
199 {
200         struct v4l2_subdev *sd = video_get_drvdata(vdev);
201         sd->devnode = NULL;
202         kfree(vdev);
203 }
204
205 int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
206 {
207         struct video_device *vdev;
208         struct v4l2_subdev *sd;
209         int err;
210
211         /* Register a device node for every subdev marked with the
212          * V4L2_SUBDEV_FL_HAS_DEVNODE flag.
213          */
214         list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
215                 if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE))
216                         continue;
217
218                 vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
219                 if (!vdev) {
220                         err = -ENOMEM;
221                         goto clean_up;
222                 }
223
224                 video_set_drvdata(vdev, sd);
225                 strlcpy(vdev->name, sd->name, sizeof(vdev->name));
226                 vdev->v4l2_dev = v4l2_dev;
227                 vdev->fops = &v4l2_subdev_fops;
228                 vdev->release = v4l2_device_release_subdev_node;
229                 vdev->ctrl_handler = sd->ctrl_handler;
230                 err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1,
231                                               sd->owner);
232                 if (err < 0) {
233                         kfree(vdev);
234                         goto clean_up;
235                 }
236 #if defined(CONFIG_MEDIA_CONTROLLER)
237                 sd->entity.info.v4l.major = VIDEO_MAJOR;
238                 sd->entity.info.v4l.minor = vdev->minor;
239 #endif
240                 sd->devnode = vdev;
241         }
242         return 0;
243
244 clean_up:
245         list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
246                 if (!sd->devnode)
247                         break;
248                 video_unregister_device(sd->devnode);
249         }
250
251         return err;
252 }
253 EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes);
254
255 void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)
256 {
257         struct v4l2_device *v4l2_dev;
258
259         /* return if it isn't registered */
260         if (sd == NULL || sd->v4l2_dev == NULL)
261                 return;
262
263         v4l2_dev = sd->v4l2_dev;
264
265         spin_lock(&v4l2_dev->lock);
266         list_del(&sd->list);
267         spin_unlock(&v4l2_dev->lock);
268
269         if (sd->internal_ops && sd->internal_ops->unregistered)
270                 sd->internal_ops->unregistered(sd);
271         sd->v4l2_dev = NULL;
272
273 #if defined(CONFIG_MEDIA_CONTROLLER)
274         if (v4l2_dev->mdev)
275                 media_device_unregister_entity(&sd->entity);
276 #endif
277         video_unregister_device(sd->devnode);
278         module_put(sd->owner);
279 }
280 EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);