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
v4l2_device_register(struct device * dev,struct v4l2_device * v4l2_dev)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
v4l2_device_release(struct kref * ref)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
v4l2_device_put(struct v4l2_device * v4l2_dev)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
v4l2_device_set_name(struct v4l2_device * v4l2_dev,const char * basename,atomic_t * instance)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
v4l2_device_disconnect(struct v4l2_device * v4l2_dev)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
v4l2_device_unregister(struct v4l2_device * v4l2_dev)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
v4l2_device_register_subdev(struct v4l2_device * v4l2_dev,struct v4l2_subdev * sd)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 goto error_module;
164 }
165
166 /* This just returns 0 if either of the two args is NULL */
167 err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler);
168 if (err)
169 goto error_unregister;
170
171 #if defined(CONFIG_MEDIA_CONTROLLER)
172 /* Register the entity. */
173 if (v4l2_dev->mdev) {
174 err = media_device_register_entity(v4l2_dev->mdev, entity);
175 if (err < 0)
176 goto error_unregister;
177 }
178 #endif
179
180 spin_lock(&v4l2_dev->lock);
181 list_add_tail(&sd->list, &v4l2_dev->subdevs);
182 spin_unlock(&v4l2_dev->lock);
183
184 return 0;
185
186 error_unregister:
187 if (sd->internal_ops && sd->internal_ops->unregistered)
188 sd->internal_ops->unregistered(sd);
189 error_module:
190 module_put(sd->owner);
191 sd->v4l2_dev = NULL;
192 return err;
193 }
194 EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
195
v4l2_device_release_subdev_node(struct video_device * vdev)196 static void v4l2_device_release_subdev_node(struct video_device *vdev)
197 {
198 struct v4l2_subdev *sd = video_get_drvdata(vdev);
199 sd->devnode = NULL;
200 kfree(vdev);
201 }
202
v4l2_device_register_subdev_nodes(struct v4l2_device * v4l2_dev)203 int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
204 {
205 struct video_device *vdev;
206 struct v4l2_subdev *sd;
207 int err;
208
209 /* Register a device node for every subdev marked with the
210 * V4L2_SUBDEV_FL_HAS_DEVNODE flag.
211 */
212 list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
213 if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE))
214 continue;
215
216 vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
217 if (!vdev) {
218 err = -ENOMEM;
219 goto clean_up;
220 }
221
222 video_set_drvdata(vdev, sd);
223 strlcpy(vdev->name, sd->name, sizeof(vdev->name));
224 vdev->v4l2_dev = v4l2_dev;
225 vdev->fops = &v4l2_subdev_fops;
226 vdev->release = v4l2_device_release_subdev_node;
227 vdev->ctrl_handler = sd->ctrl_handler;
228 err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1,
229 sd->owner);
230 if (err < 0) {
231 kfree(vdev);
232 goto clean_up;
233 }
234 #if defined(CONFIG_MEDIA_CONTROLLER)
235 sd->entity.info.v4l.major = VIDEO_MAJOR;
236 sd->entity.info.v4l.minor = vdev->minor;
237 #endif
238 sd->devnode = vdev;
239 }
240 return 0;
241
242 clean_up:
243 list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
244 if (!sd->devnode)
245 break;
246 video_unregister_device(sd->devnode);
247 }
248
249 return err;
250 }
251 EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes);
252
v4l2_device_unregister_subdev(struct v4l2_subdev * sd)253 void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)
254 {
255 struct v4l2_device *v4l2_dev;
256
257 /* return if it isn't registered */
258 if (sd == NULL || sd->v4l2_dev == NULL)
259 return;
260
261 v4l2_dev = sd->v4l2_dev;
262
263 spin_lock(&v4l2_dev->lock);
264 list_del(&sd->list);
265 spin_unlock(&v4l2_dev->lock);
266
267 if (sd->internal_ops && sd->internal_ops->unregistered)
268 sd->internal_ops->unregistered(sd);
269 sd->v4l2_dev = NULL;
270
271 #if defined(CONFIG_MEDIA_CONTROLLER)
272 if (v4l2_dev->mdev)
273 media_device_unregister_entity(&sd->entity);
274 #endif
275 video_unregister_device(sd->devnode);
276 module_put(sd->owner);
277 }
278 EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);
279