Merge remote-tracking branch 'battery/for-next'
[deliverable/linux.git] / drivers / media / v4l2-core / v4l2-device.c
CommitLineData
2a1fcdf0
HV
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>
7a707b89 23#include <linux/module.h>
2a1fcdf0 24#include <linux/i2c.h>
3e0ec41c 25#include <linux/slab.h>
85e09219
DB
26#if defined(CONFIG_SPI)
27#include <linux/spi/spi.h>
28#endif
2a1fcdf0
HV
29#include <linux/videodev2.h>
30#include <media/v4l2-device.h>
11bbc1ca 31#include <media/v4l2-ctrls.h>
2a1fcdf0
HV
32
33int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev)
34{
3a63e449 35 if (v4l2_dev == NULL)
2a1fcdf0 36 return -EINVAL;
3a63e449 37
2a1fcdf0
HV
38 INIT_LIST_HEAD(&v4l2_dev->subdevs);
39 spin_lock_init(&v4l2_dev->lock);
0f62fd6a 40 v4l2_prio_init(&v4l2_dev->prio);
bedf8bcf 41 kref_init(&v4l2_dev->ref);
236c5441 42 get_device(dev);
2a1fcdf0 43 v4l2_dev->dev = dev;
3a63e449
HV
44 if (dev == NULL) {
45 /* If dev == NULL, then name must be filled in by the caller */
9e882e3b
HV
46 if (WARN_ON(!v4l2_dev->name[0]))
47 return -EINVAL;
3a63e449
HV
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",
c3ef01ce 54 dev->driver->name, dev_name(dev));
95db3a60
LP
55 if (!dev_get_drvdata(dev))
56 dev_set_drvdata(dev, v4l2_dev);
2a1fcdf0
HV
57 return 0;
58}
59EXPORT_SYMBOL_GPL(v4l2_device_register);
60
bedf8bcf
HV
61static 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
70int v4l2_device_put(struct v4l2_device *v4l2_dev)
71{
72 return kref_put(&v4l2_dev->ref, v4l2_device_release);
73}
74EXPORT_SYMBOL_GPL(v4l2_device_put);
75
102e7813
HV
76int 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}
90EXPORT_SYMBOL_GPL(v4l2_device_set_name);
91
ae6cfaac
HV
92void v4l2_device_disconnect(struct v4l2_device *v4l2_dev)
93{
95db3a60
LP
94 if (v4l2_dev->dev == NULL)
95 return;
96
97 if (dev_get_drvdata(v4l2_dev->dev) == v4l2_dev)
ae6cfaac 98 dev_set_drvdata(v4l2_dev->dev, NULL);
236c5441 99 put_device(v4l2_dev->dev);
95db3a60 100 v4l2_dev->dev = NULL;
ae6cfaac
HV
101}
102EXPORT_SYMBOL_GPL(v4l2_device_disconnect);
103
2a1fcdf0
HV
104void v4l2_device_unregister(struct v4l2_device *v4l2_dev)
105{
106 struct v4l2_subdev *sd, *next;
107
9e882e3b
HV
108 /* Just return if v4l2_dev is NULL or if it was already
109 * unregistered before. */
110 if (v4l2_dev == NULL || !v4l2_dev->name[0])
2a1fcdf0 111 return;
ae6cfaac
HV
112 v4l2_device_disconnect(v4l2_dev);
113
3a63e449 114 /* Unregister subdevs */
b5b2b7ed 115 list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list) {
2a1fcdf0 116 v4l2_device_unregister_subdev(sd);
7b34be71 117#if IS_ENABLED(CONFIG_I2C)
b5b2b7ed
HV
118 if (sd->flags & V4L2_SUBDEV_FL_IS_I2C) {
119 struct i2c_client *client = v4l2_get_subdevdata(sd);
120
0d51ebd3
TF
121 /*
122 * We need to unregister the i2c client
123 * explicitly. We cannot rely on
124 * i2c_del_adapter to always unregister
125 * clients for us, since if the i2c bus is a
126 * platform bus, then it is never deleted.
127 *
128 * Device tree or ACPI based devices must not
129 * be unregistered as they have not been
130 * registered by us, and would not be
131 * re-created by just probing the V4L2 driver.
132 */
133 if (client &&
134 !client->dev.of_node && !client->dev.fwnode)
b5b2b7ed 135 i2c_unregister_device(client);
672dcd54 136 continue;
b5b2b7ed 137 }
85e09219
DB
138#endif
139#if defined(CONFIG_SPI)
140 if (sd->flags & V4L2_SUBDEV_FL_IS_SPI) {
141 struct spi_device *spi = v4l2_get_subdevdata(sd);
142
0d51ebd3 143 if (spi && !spi->dev.of_node && !spi->dev.fwnode)
85e09219 144 spi_unregister_device(spi);
672dcd54 145 continue;
85e09219 146 }
b7fd6067 147#endif
b5b2b7ed 148 }
9e882e3b
HV
149 /* Mark as unregistered, thus preventing duplicate unregistrations */
150 v4l2_dev->name[0] = '\0';
2a1fcdf0
HV
151}
152EXPORT_SYMBOL_GPL(v4l2_device_unregister);
153
3a63e449 154int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
61f5db54 155 struct v4l2_subdev *sd)
2a1fcdf0 156{
61f5db54
LP
157#if defined(CONFIG_MEDIA_CONTROLLER)
158 struct media_entity *entity = &sd->entity;
159#endif
11bbc1ca
HV
160 int err;
161
2a1fcdf0 162 /* Check for valid input */
fc490717 163 if (!v4l2_dev || !sd || sd->v4l2_dev || !sd->name[0])
2a1fcdf0 164 return -EINVAL;
2096a5dc 165
b2a06aec
SA
166 /*
167 * The reason to acquire the module here is to avoid unloading
168 * a module of sub-device which is registered to a media
169 * device. To make it possible to unload modules for media
170 * devices that also register sub-devices, do not
171 * try_module_get() such sub-device owners.
172 */
173 sd->owner_v4l2_dev = v4l2_dev->dev && v4l2_dev->dev->driver &&
174 sd->owner == v4l2_dev->dev->driver->owner;
175
176 if (!sd->owner_v4l2_dev && !try_module_get(sd->owner))
2a1fcdf0 177 return -ENODEV;
2096a5dc 178
45f6f84a 179 sd->v4l2_dev = v4l2_dev;
11bbc1ca 180 /* This just returns 0 if either of the two args is NULL */
34a6b7d0 181 err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler, NULL);
317efce9 182 if (err)
bdf5c198 183 goto error_module;
2096a5dc 184
61f5db54
LP
185#if defined(CONFIG_MEDIA_CONTROLLER)
186 /* Register the entity. */
187 if (v4l2_dev->mdev) {
188 err = media_device_register_entity(v4l2_dev->mdev, entity);
317efce9 189 if (err < 0)
bdf5c198 190 goto error_module;
61f5db54
LP
191 }
192#endif
193
bdf5c198
SA
194 if (sd->internal_ops && sd->internal_ops->registered) {
195 err = sd->internal_ops->registered(sd);
196 if (err)
197 goto error_unregister;
198 }
199
3a63e449
HV
200 spin_lock(&v4l2_dev->lock);
201 list_add_tail(&sd->list, &v4l2_dev->subdevs);
202 spin_unlock(&v4l2_dev->lock);
2096a5dc 203
2a1fcdf0 204 return 0;
317efce9
LP
205
206error_unregister:
bdf5c198
SA
207#if defined(CONFIG_MEDIA_CONTROLLER)
208 media_device_unregister_entity(entity);
209#endif
317efce9 210error_module:
b2a06aec
SA
211 if (!sd->owner_v4l2_dev)
212 module_put(sd->owner);
317efce9
LP
213 sd->v4l2_dev = NULL;
214 return err;
2a1fcdf0
HV
215}
216EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
217
3e0ec41c
GL
218static void v4l2_device_release_subdev_node(struct video_device *vdev)
219{
220 struct v4l2_subdev *sd = video_get_drvdata(vdev);
221 sd->devnode = NULL;
222 kfree(vdev);
223}
224
2096a5dc
LP
225int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
226{
227 struct video_device *vdev;
228 struct v4l2_subdev *sd;
229 int err;
230
231 /* Register a device node for every subdev marked with the
232 * V4L2_SUBDEV_FL_HAS_DEVNODE flag.
233 */
234 list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
235 if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE))
236 continue;
237
3e0ec41c
GL
238 vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
239 if (!vdev) {
240 err = -ENOMEM;
241 goto clean_up;
242 }
243
244 video_set_drvdata(vdev, sd);
2096a5dc
LP
245 strlcpy(vdev->name, sd->name, sizeof(vdev->name));
246 vdev->v4l2_dev = v4l2_dev;
247 vdev->fops = &v4l2_subdev_fops;
3e0ec41c 248 vdev->release = v4l2_device_release_subdev_node;
18d171ba 249 vdev->ctrl_handler = sd->ctrl_handler;
2096a5dc
LP
250 err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1,
251 sd->owner);
3e0ec41c
GL
252 if (err < 0) {
253 kfree(vdev);
254 goto clean_up;
255 }
61f5db54 256#if defined(CONFIG_MEDIA_CONTROLLER)
e31a0ba7
MCC
257 sd->entity.info.dev.major = VIDEO_MAJOR;
258 sd->entity.info.dev.minor = vdev->minor;
d9c21e3e
MCC
259
260 /* Interface is created by __video_register_device() */
261 if (vdev->v4l2_dev->mdev) {
262 struct media_link *link;
263
264 link = media_create_intf_link(&sd->entity,
265 &vdev->intf_devnode->intf,
13f6e888 266 MEDIA_LNK_FL_ENABLED);
1630b832
DC
267 if (!link) {
268 err = -ENOMEM;
d9c21e3e 269 goto clean_up;
1630b832 270 }
d9c21e3e 271 }
61f5db54 272#endif
3e0ec41c 273 sd->devnode = vdev;
2096a5dc 274 }
2096a5dc 275 return 0;
3e0ec41c
GL
276
277clean_up:
278 list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
279 if (!sd->devnode)
280 break;
281 video_unregister_device(sd->devnode);
282 }
283
284 return err;
2096a5dc
LP
285}
286EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes);
287
2a1fcdf0
HV
288void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)
289{
61f5db54
LP
290 struct v4l2_device *v4l2_dev;
291
2a1fcdf0 292 /* return if it isn't registered */
b0167600 293 if (sd == NULL || sd->v4l2_dev == NULL)
2a1fcdf0 294 return;
2096a5dc 295
61f5db54
LP
296 v4l2_dev = sd->v4l2_dev;
297
298 spin_lock(&v4l2_dev->lock);
2a1fcdf0 299 list_del(&sd->list);
61f5db54
LP
300 spin_unlock(&v4l2_dev->lock);
301
45f6f84a
HV
302 if (sd->internal_ops && sd->internal_ops->unregistered)
303 sd->internal_ops->unregistered(sd);
b0167600 304 sd->v4l2_dev = NULL;
2096a5dc 305
61f5db54 306#if defined(CONFIG_MEDIA_CONTROLLER)
c2efd3e6 307 if (v4l2_dev->mdev) {
d9c21e3e
MCC
308 /*
309 * No need to explicitly remove links, as both pads and
310 * links are removed by the function below, in the right order
311 */
61f5db54 312 media_device_unregister_entity(&sd->entity);
c2efd3e6 313 }
61f5db54 314#endif
3e0ec41c 315 video_unregister_device(sd->devnode);
b2a06aec
SA
316 if (!sd->owner_v4l2_dev)
317 module_put(sd->owner);
2a1fcdf0
HV
318}
319EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);
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