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/i2c.h>
24 #if defined(CONFIG_SPI)
25 #include <linux/spi/spi.h>
26 #endif
27 #include <linux/videodev2.h>
28 #include <media/v4l2-device.h>
29 #include <media/v4l2-ctrls.h>
30
v4l2_device_register(struct device * dev,struct v4l2_device * v4l2_dev)31 int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev)
32 {
33 if (v4l2_dev == NULL)
34 return -EINVAL;
35
36 INIT_LIST_HEAD(&v4l2_dev->subdevs);
37 spin_lock_init(&v4l2_dev->lock);
38 mutex_init(&v4l2_dev->ioctl_lock);
39 v4l2_prio_init(&v4l2_dev->prio);
40 kref_init(&v4l2_dev->ref);
41 v4l2_dev->dev = dev;
42 if (dev == NULL) {
43 /* If dev == NULL, then name must be filled in by the caller */
44 WARN_ON(!v4l2_dev->name[0]);
45 return 0;
46 }
47
48 /* Set name to driver name + device name if it is empty. */
49 if (!v4l2_dev->name[0])
50 snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s",
51 dev->driver->name, dev_name(dev));
52 if (!dev_get_drvdata(dev))
53 dev_set_drvdata(dev, v4l2_dev);
54 return 0;
55 }
56 EXPORT_SYMBOL_GPL(v4l2_device_register);
57
v4l2_device_release(struct kref * ref)58 static void v4l2_device_release(struct kref *ref)
59 {
60 struct v4l2_device *v4l2_dev =
61 container_of(ref, struct v4l2_device, ref);
62
63 if (v4l2_dev->release)
64 v4l2_dev->release(v4l2_dev);
65 }
66
v4l2_device_put(struct v4l2_device * v4l2_dev)67 int v4l2_device_put(struct v4l2_device *v4l2_dev)
68 {
69 return kref_put(&v4l2_dev->ref, v4l2_device_release);
70 }
71 EXPORT_SYMBOL_GPL(v4l2_device_put);
72
v4l2_device_set_name(struct v4l2_device * v4l2_dev,const char * basename,atomic_t * instance)73 int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename,
74 atomic_t *instance)
75 {
76 int num = atomic_inc_return(instance) - 1;
77 int len = strlen(basename);
78
79 if (basename[len - 1] >= '0' && basename[len - 1] <= '9')
80 snprintf(v4l2_dev->name, sizeof(v4l2_dev->name),
81 "%s-%d", basename, num);
82 else
83 snprintf(v4l2_dev->name, sizeof(v4l2_dev->name),
84 "%s%d", basename, num);
85 return num;
86 }
87 EXPORT_SYMBOL_GPL(v4l2_device_set_name);
88
v4l2_device_disconnect(struct v4l2_device * v4l2_dev)89 void v4l2_device_disconnect(struct v4l2_device *v4l2_dev)
90 {
91 if (v4l2_dev->dev == NULL)
92 return;
93
94 if (dev_get_drvdata(v4l2_dev->dev) == v4l2_dev)
95 dev_set_drvdata(v4l2_dev->dev, NULL);
96 v4l2_dev->dev = NULL;
97 }
98 EXPORT_SYMBOL_GPL(v4l2_device_disconnect);
99
v4l2_device_unregister(struct v4l2_device * v4l2_dev)100 void v4l2_device_unregister(struct v4l2_device *v4l2_dev)
101 {
102 struct v4l2_subdev *sd, *next;
103
104 if (v4l2_dev == NULL)
105 return;
106 v4l2_device_disconnect(v4l2_dev);
107
108 /* Unregister subdevs */
109 list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list) {
110 v4l2_device_unregister_subdev(sd);
111 #if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))
112 if (sd->flags & V4L2_SUBDEV_FL_IS_I2C) {
113 struct i2c_client *client = v4l2_get_subdevdata(sd);
114
115 /* We need to unregister the i2c client explicitly.
116 We cannot rely on i2c_del_adapter to always
117 unregister clients for us, since if the i2c bus
118 is a platform bus, then it is never deleted. */
119 if (client)
120 i2c_unregister_device(client);
121 continue;
122 }
123 #endif
124 #if defined(CONFIG_SPI)
125 if (sd->flags & V4L2_SUBDEV_FL_IS_SPI) {
126 struct spi_device *spi = v4l2_get_subdevdata(sd);
127
128 if (spi)
129 spi_unregister_device(spi);
130 continue;
131 }
132 #endif
133 }
134 }
135 EXPORT_SYMBOL_GPL(v4l2_device_unregister);
136
v4l2_device_register_subdev(struct v4l2_device * v4l2_dev,struct v4l2_subdev * sd)137 int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
138 struct v4l2_subdev *sd)
139 {
140 #if defined(CONFIG_MEDIA_CONTROLLER)
141 struct media_entity *entity = &sd->entity;
142 #endif
143 int err;
144
145 /* Check for valid input */
146 if (v4l2_dev == NULL || sd == NULL || !sd->name[0])
147 return -EINVAL;
148
149 /* Warn if we apparently re-register a subdev */
150 WARN_ON(sd->v4l2_dev != NULL);
151
152 if (!try_module_get(sd->owner))
153 return -ENODEV;
154
155 sd->v4l2_dev = v4l2_dev;
156 if (sd->internal_ops && sd->internal_ops->registered) {
157 err = sd->internal_ops->registered(sd);
158 if (err) {
159 module_put(sd->owner);
160 return err;
161 }
162 }
163
164 /* This just returns 0 if either of the two args is NULL */
165 err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler);
166 if (err) {
167 if (sd->internal_ops && sd->internal_ops->unregistered)
168 sd->internal_ops->unregistered(sd);
169 module_put(sd->owner);
170 return err;
171 }
172
173 #if defined(CONFIG_MEDIA_CONTROLLER)
174 /* Register the entity. */
175 if (v4l2_dev->mdev) {
176 err = media_device_register_entity(v4l2_dev->mdev, entity);
177 if (err < 0) {
178 if (sd->internal_ops && sd->internal_ops->unregistered)
179 sd->internal_ops->unregistered(sd);
180 module_put(sd->owner);
181 return err;
182 }
183 }
184 #endif
185
186 spin_lock(&v4l2_dev->lock);
187 list_add_tail(&sd->list, &v4l2_dev->subdevs);
188 spin_unlock(&v4l2_dev->lock);
189
190 return 0;
191 }
192 EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
193
v4l2_device_register_subdev_nodes(struct v4l2_device * v4l2_dev)194 int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
195 {
196 struct video_device *vdev;
197 struct v4l2_subdev *sd;
198 int err;
199
200 /* Register a device node for every subdev marked with the
201 * V4L2_SUBDEV_FL_HAS_DEVNODE flag.
202 */
203 list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
204 if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE))
205 continue;
206
207 vdev = &sd->devnode;
208 strlcpy(vdev->name, sd->name, sizeof(vdev->name));
209 vdev->v4l2_dev = v4l2_dev;
210 vdev->fops = &v4l2_subdev_fops;
211 vdev->release = video_device_release_empty;
212 err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1,
213 sd->owner);
214 if (err < 0)
215 return err;
216 #if defined(CONFIG_MEDIA_CONTROLLER)
217 sd->entity.v4l.major = VIDEO_MAJOR;
218 sd->entity.v4l.minor = vdev->minor;
219 #endif
220 }
221 return 0;
222 }
223 EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes);
224
v4l2_device_unregister_subdev(struct v4l2_subdev * sd)225 void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)
226 {
227 struct v4l2_device *v4l2_dev;
228
229 /* return if it isn't registered */
230 if (sd == NULL || sd->v4l2_dev == NULL)
231 return;
232
233 v4l2_dev = sd->v4l2_dev;
234
235 spin_lock(&v4l2_dev->lock);
236 list_del(&sd->list);
237 spin_unlock(&v4l2_dev->lock);
238
239 if (sd->internal_ops && sd->internal_ops->unregistered)
240 sd->internal_ops->unregistered(sd);
241 sd->v4l2_dev = NULL;
242
243 #if defined(CONFIG_MEDIA_CONTROLLER)
244 if (v4l2_dev->mdev)
245 media_device_unregister_entity(&sd->entity);
246 #endif
247 video_unregister_device(&sd->devnode);
248 module_put(sd->owner);
249 }
250 EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);
251