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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
33int 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 if (WARN_ON(!v4l2_dev->name[0]))
48 return -EINVAL;
49 return 0;
50 }
51
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);
58 return 0;
59}
60EXPORT_SYMBOL_GPL(v4l2_device_register);
61
62static void v4l2_device_release(struct kref *ref)
63{
64 struct v4l2_device *v4l2_dev =
65 container_of(ref, struct v4l2_device, ref);
66
67 if (v4l2_dev->release)
68 v4l2_dev->release(v4l2_dev);
69}
70
71int v4l2_device_put(struct v4l2_device *v4l2_dev)
72{
73 return kref_put(&v4l2_dev->ref, v4l2_device_release);
74}
75EXPORT_SYMBOL_GPL(v4l2_device_put);
76
77int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename,
78 atomic_t *instance)
79{
80 int num = atomic_inc_return(instance) - 1;
81 int len = strlen(basename);
82
83 if (basename[len - 1] >= '0' && basename[len - 1] <= '9')
84 snprintf(v4l2_dev->name, sizeof(v4l2_dev->name),
85 "%s-%d", basename, num);
86 else
87 snprintf(v4l2_dev->name, sizeof(v4l2_dev->name),
88 "%s%d", basename, num);
89 return num;
90}
91EXPORT_SYMBOL_GPL(v4l2_device_set_name);
92
93void v4l2_device_disconnect(struct v4l2_device *v4l2_dev)
94{
95 if (v4l2_dev->dev == NULL)
96 return;
97
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;
102}
103EXPORT_SYMBOL_GPL(v4l2_device_disconnect);
104
105void v4l2_device_unregister(struct v4l2_device *v4l2_dev)
106{
107 struct v4l2_subdev *sd, *next;
108
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])
112 return;
113 v4l2_device_disconnect(v4l2_dev);
114
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);
121
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. */
126 if (client)
127 i2c_unregister_device(client);
128 continue;
129 }
130#endif
131#if defined(CONFIG_SPI)
132 if (sd->flags & V4L2_SUBDEV_FL_IS_SPI) {
133 struct spi_device *spi = v4l2_get_subdevdata(sd);
134
135 if (spi)
136 spi_unregister_device(spi);
137 continue;
138 }
139#endif
140 }
141 /* Mark as unregistered, thus preventing duplicate unregistrations */
142 v4l2_dev->name[0] = '\0';
143}
144EXPORT_SYMBOL_GPL(v4l2_device_unregister);
145
146int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
147 struct v4l2_subdev *sd)
148{
149#if defined(CONFIG_MEDIA_CONTROLLER)
150 struct media_entity *entity = &sd->entity;
151#endif
152 int err;
153
154 /* Check for valid input */
155 if (v4l2_dev == NULL || sd == NULL || !sd->name[0])
156 return -EINVAL;
157
158 /* Warn if we apparently re-register a subdev */
159 WARN_ON(sd->v4l2_dev != NULL);
160
161 if (!try_module_get(sd->owner))
162 return -ENODEV;
163
164 sd->v4l2_dev = v4l2_dev;
165 if (sd->internal_ops && sd->internal_ops->registered) {
166 err = sd->internal_ops->registered(sd);
167 if (err)
168 goto error_module;
169 }
170
171 /* This just returns 0 if either of the two args is NULL */
172 err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler, NULL);
173 if (err)
174 goto error_unregister;
175
176#if defined(CONFIG_MEDIA_CONTROLLER)
177 /* Register the entity. */
178 if (v4l2_dev->mdev) {
179 err = media_device_register_entity(v4l2_dev->mdev, entity);
180 if (err < 0)
181 goto error_unregister;
182 }
183#endif
184
185 spin_lock(&v4l2_dev->lock);
186 list_add_tail(&sd->list, &v4l2_dev->subdevs);
187 spin_unlock(&v4l2_dev->lock);
188
189 return 0;
190
191error_unregister:
192 if (sd->internal_ops && sd->internal_ops->unregistered)
193 sd->internal_ops->unregistered(sd);
194error_module:
195 module_put(sd->owner);
196 sd->v4l2_dev = NULL;
197 return err;
198}
199EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
200
201static void v4l2_device_release_subdev_node(struct video_device *vdev)
202{
203 struct v4l2_subdev *sd = video_get_drvdata(vdev);
204 sd->devnode = NULL;
205 kfree(vdev);
206}
207
208int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
209{
210 struct video_device *vdev;
211 struct v4l2_subdev *sd;
212 int err;
213
214 /* Register a device node for every subdev marked with the
215 * V4L2_SUBDEV_FL_HAS_DEVNODE flag.
216 */
217 list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
218 if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE))
219 continue;
220
221 vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
222 if (!vdev) {
223 err = -ENOMEM;
224 goto clean_up;
225 }
226
227 video_set_drvdata(vdev, sd);
228 strlcpy(vdev->name, sd->name, sizeof(vdev->name));
229 vdev->v4l2_dev = v4l2_dev;
230 vdev->fops = &v4l2_subdev_fops;
231 vdev->release = v4l2_device_release_subdev_node;
232 vdev->ctrl_handler = sd->ctrl_handler;
233 err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1,
234 sd->owner);
235 if (err < 0) {
236 kfree(vdev);
237 goto clean_up;
238 }
239#if defined(CONFIG_MEDIA_CONTROLLER)
240 sd->entity.info.v4l.major = VIDEO_MAJOR;
241 sd->entity.info.v4l.minor = vdev->minor;
242#endif
243 sd->devnode = vdev;
244 }
245 return 0;
246
247clean_up:
248 list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
249 if (!sd->devnode)
250 break;
251 video_unregister_device(sd->devnode);
252 }
253
254 return err;
255}
256EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes);
257
258void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)
259{
260 struct v4l2_device *v4l2_dev;
261
262 /* return if it isn't registered */
263 if (sd == NULL || sd->v4l2_dev == NULL)
264 return;
265
266 v4l2_dev = sd->v4l2_dev;
267
268 spin_lock(&v4l2_dev->lock);
269 list_del(&sd->list);
270 spin_unlock(&v4l2_dev->lock);
271
272 if (sd->internal_ops && sd->internal_ops->unregistered)
273 sd->internal_ops->unregistered(sd);
274 sd->v4l2_dev = NULL;
275
276#if defined(CONFIG_MEDIA_CONTROLLER)
277 if (v4l2_dev->mdev) {
278 media_entity_remove_links(&sd->entity);
279 media_device_unregister_entity(&sd->entity);
280 }
281#endif
282 video_unregister_device(sd->devnode);
283 module_put(sd->owner);
284}
285EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);