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Commit | Line | Data |
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27a5e6d3 HV |
1 | /* |
2 | * Video capture interface for Linux version 2 | |
3 | * | |
4 | * A generic video device interface for the LINUX operating system | |
5 | * using a set of device structures/vectors for low level operations. | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
11 | * | |
d9b01449 | 12 | * Authors: Alan Cox, <alan@lxorguk.ukuu.org.uk> (version 1) |
27a5e6d3 HV |
13 | * Mauro Carvalho Chehab <mchehab@infradead.org> (version 2) |
14 | * | |
15 | * Fixes: 20000516 Claudio Matsuoka <claudio@conectiva.com> | |
16 | * - Added procfs support | |
17 | */ | |
18 | ||
19 | #include <linux/module.h> | |
20 | #include <linux/types.h> | |
21 | #include <linux/kernel.h> | |
22 | #include <linux/mm.h> | |
23 | #include <linux/string.h> | |
24 | #include <linux/errno.h> | |
25 | #include <linux/init.h> | |
26 | #include <linux/kmod.h> | |
27 | #include <linux/slab.h> | |
27a5e6d3 HV |
28 | #include <asm/uaccess.h> |
29 | #include <asm/system.h> | |
30 | ||
31 | #include <media/v4l2-common.h> | |
9bea3514 | 32 | #include <media/v4l2-device.h> |
bec43661 | 33 | #include <media/v4l2-ioctl.h> |
27a5e6d3 HV |
34 | |
35 | #define VIDEO_NUM_DEVICES 256 | |
36 | #define VIDEO_NAME "video4linux" | |
37 | ||
38 | /* | |
39 | * sysfs stuff | |
40 | */ | |
41 | ||
42 | static ssize_t show_index(struct device *cd, | |
43 | struct device_attribute *attr, char *buf) | |
44 | { | |
dc93a70c | 45 | struct video_device *vdev = to_video_device(cd); |
bfa8a273 | 46 | |
dc93a70c | 47 | return sprintf(buf, "%i\n", vdev->index); |
27a5e6d3 HV |
48 | } |
49 | ||
50 | static ssize_t show_name(struct device *cd, | |
51 | struct device_attribute *attr, char *buf) | |
52 | { | |
dc93a70c | 53 | struct video_device *vdev = to_video_device(cd); |
bfa8a273 | 54 | |
dc93a70c | 55 | return sprintf(buf, "%.*s\n", (int)sizeof(vdev->name), vdev->name); |
27a5e6d3 HV |
56 | } |
57 | ||
58 | static struct device_attribute video_device_attrs[] = { | |
59 | __ATTR(name, S_IRUGO, show_name, NULL), | |
60 | __ATTR(index, S_IRUGO, show_index, NULL), | |
61 | __ATTR_NULL | |
62 | }; | |
63 | ||
7f8ecfab HV |
64 | /* |
65 | * Active devices | |
66 | */ | |
67 | static struct video_device *video_device[VIDEO_NUM_DEVICES]; | |
68 | static DEFINE_MUTEX(videodev_lock); | |
22e22125 | 69 | static DECLARE_BITMAP(devnode_nums[VFL_TYPE_MAX], VIDEO_NUM_DEVICES); |
7f8ecfab | 70 | |
5062cb70 HV |
71 | /* Device node utility functions */ |
72 | ||
73 | /* Note: these utility functions all assume that vfl_type is in the range | |
74 | [0, VFL_TYPE_MAX-1]. */ | |
75 | ||
76 | #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES | |
77 | /* Return the bitmap corresponding to vfl_type. */ | |
78 | static inline unsigned long *devnode_bits(int vfl_type) | |
79 | { | |
80 | /* Any types not assigned to fixed minor ranges must be mapped to | |
81 | one single bitmap for the purposes of finding a free node number | |
82 | since all those unassigned types use the same minor range. */ | |
226c0eea | 83 | int idx = (vfl_type > VFL_TYPE_RADIO) ? VFL_TYPE_MAX - 1 : vfl_type; |
5062cb70 HV |
84 | |
85 | return devnode_nums[idx]; | |
86 | } | |
87 | #else | |
88 | /* Return the bitmap corresponding to vfl_type. */ | |
89 | static inline unsigned long *devnode_bits(int vfl_type) | |
90 | { | |
91 | return devnode_nums[vfl_type]; | |
92 | } | |
93 | #endif | |
94 | ||
95 | /* Mark device node number vdev->num as used */ | |
96 | static inline void devnode_set(struct video_device *vdev) | |
97 | { | |
98 | set_bit(vdev->num, devnode_bits(vdev->vfl_type)); | |
99 | } | |
100 | ||
101 | /* Mark device node number vdev->num as unused */ | |
102 | static inline void devnode_clear(struct video_device *vdev) | |
103 | { | |
104 | clear_bit(vdev->num, devnode_bits(vdev->vfl_type)); | |
105 | } | |
106 | ||
107 | /* Try to find a free device node number in the range [from, to> */ | |
108 | static inline int devnode_find(struct video_device *vdev, int from, int to) | |
109 | { | |
110 | return find_next_zero_bit(devnode_bits(vdev->vfl_type), to, from); | |
111 | } | |
112 | ||
27a5e6d3 HV |
113 | struct video_device *video_device_alloc(void) |
114 | { | |
bfa8a273 | 115 | return kzalloc(sizeof(struct video_device), GFP_KERNEL); |
27a5e6d3 HV |
116 | } |
117 | EXPORT_SYMBOL(video_device_alloc); | |
118 | ||
dc93a70c | 119 | void video_device_release(struct video_device *vdev) |
27a5e6d3 | 120 | { |
dc93a70c | 121 | kfree(vdev); |
27a5e6d3 HV |
122 | } |
123 | EXPORT_SYMBOL(video_device_release); | |
124 | ||
dc93a70c | 125 | void video_device_release_empty(struct video_device *vdev) |
f9e86b5e HV |
126 | { |
127 | /* Do nothing */ | |
128 | /* Only valid when the video_device struct is a static. */ | |
129 | } | |
130 | EXPORT_SYMBOL(video_device_release_empty); | |
131 | ||
dc93a70c | 132 | static inline void video_get(struct video_device *vdev) |
7f8ecfab | 133 | { |
dc93a70c HV |
134 | get_device(&vdev->dev); |
135 | } | |
136 | ||
137 | static inline void video_put(struct video_device *vdev) | |
138 | { | |
139 | put_device(&vdev->dev); | |
140 | } | |
141 | ||
142 | /* Called when the last user of the video device exits. */ | |
143 | static void v4l2_device_release(struct device *cd) | |
144 | { | |
145 | struct video_device *vdev = to_video_device(cd); | |
bedf8bcf | 146 | struct v4l2_device *v4l2_dev = vdev->v4l2_dev; |
7f8ecfab HV |
147 | |
148 | mutex_lock(&videodev_lock); | |
dc93a70c | 149 | if (video_device[vdev->minor] != vdev) { |
6ea9a182 | 150 | mutex_unlock(&videodev_lock); |
dc93a70c HV |
151 | /* should not happen */ |
152 | WARN_ON(1); | |
6ea9a182 HV |
153 | return; |
154 | } | |
7f8ecfab HV |
155 | |
156 | /* Free up this device for reuse */ | |
dc93a70c | 157 | video_device[vdev->minor] = NULL; |
7f8ecfab | 158 | |
dc93a70c HV |
159 | /* Delete the cdev on this minor as well */ |
160 | cdev_del(vdev->cdev); | |
161 | /* Just in case some driver tries to access this from | |
162 | the release() callback. */ | |
163 | vdev->cdev = NULL; | |
7f8ecfab | 164 | |
22e22125 | 165 | /* Mark device node number as free */ |
5062cb70 | 166 | devnode_clear(vdev); |
7f8ecfab | 167 | |
dc93a70c | 168 | mutex_unlock(&videodev_lock); |
27a5e6d3 | 169 | |
dc93a70c HV |
170 | /* Release video_device and perform other |
171 | cleanups as needed. */ | |
172 | vdev->release(vdev); | |
bedf8bcf HV |
173 | |
174 | /* Decrease v4l2_device refcount */ | |
175 | if (v4l2_dev) | |
176 | v4l2_device_put(v4l2_dev); | |
27a5e6d3 HV |
177 | } |
178 | ||
179 | static struct class video_class = { | |
180 | .name = VIDEO_NAME, | |
181 | .dev_attrs = video_device_attrs, | |
27a5e6d3 HV |
182 | }; |
183 | ||
27a5e6d3 HV |
184 | struct video_device *video_devdata(struct file *file) |
185 | { | |
186 | return video_device[iminor(file->f_path.dentry->d_inode)]; | |
187 | } | |
188 | EXPORT_SYMBOL(video_devdata); | |
189 | ||
02265493 HV |
190 | |
191 | /* Priority handling */ | |
192 | ||
193 | static inline bool prio_is_valid(enum v4l2_priority prio) | |
194 | { | |
195 | return prio == V4L2_PRIORITY_BACKGROUND || | |
196 | prio == V4L2_PRIORITY_INTERACTIVE || | |
197 | prio == V4L2_PRIORITY_RECORD; | |
198 | } | |
199 | ||
200 | void v4l2_prio_init(struct v4l2_prio_state *global) | |
201 | { | |
202 | memset(global, 0, sizeof(*global)); | |
203 | } | |
204 | EXPORT_SYMBOL(v4l2_prio_init); | |
205 | ||
206 | int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local, | |
207 | enum v4l2_priority new) | |
208 | { | |
209 | if (!prio_is_valid(new)) | |
210 | return -EINVAL; | |
211 | if (*local == new) | |
212 | return 0; | |
213 | ||
214 | atomic_inc(&global->prios[new]); | |
215 | if (prio_is_valid(*local)) | |
216 | atomic_dec(&global->prios[*local]); | |
217 | *local = new; | |
218 | return 0; | |
219 | } | |
220 | EXPORT_SYMBOL(v4l2_prio_change); | |
221 | ||
222 | void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local) | |
223 | { | |
224 | v4l2_prio_change(global, local, V4L2_PRIORITY_DEFAULT); | |
225 | } | |
226 | EXPORT_SYMBOL(v4l2_prio_open); | |
227 | ||
228 | void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local) | |
229 | { | |
230 | if (prio_is_valid(local)) | |
231 | atomic_dec(&global->prios[local]); | |
232 | } | |
233 | EXPORT_SYMBOL(v4l2_prio_close); | |
234 | ||
235 | enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global) | |
236 | { | |
237 | if (atomic_read(&global->prios[V4L2_PRIORITY_RECORD]) > 0) | |
238 | return V4L2_PRIORITY_RECORD; | |
239 | if (atomic_read(&global->prios[V4L2_PRIORITY_INTERACTIVE]) > 0) | |
240 | return V4L2_PRIORITY_INTERACTIVE; | |
241 | if (atomic_read(&global->prios[V4L2_PRIORITY_BACKGROUND]) > 0) | |
242 | return V4L2_PRIORITY_BACKGROUND; | |
243 | return V4L2_PRIORITY_UNSET; | |
244 | } | |
245 | EXPORT_SYMBOL(v4l2_prio_max); | |
246 | ||
247 | int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local) | |
248 | { | |
249 | return (local < v4l2_prio_max(global)) ? -EBUSY : 0; | |
250 | } | |
251 | EXPORT_SYMBOL(v4l2_prio_check); | |
252 | ||
253 | ||
dc93a70c HV |
254 | static ssize_t v4l2_read(struct file *filp, char __user *buf, |
255 | size_t sz, loff_t *off) | |
256 | { | |
257 | struct video_device *vdev = video_devdata(filp); | |
2877842d | 258 | int ret = -ENODEV; |
dc93a70c HV |
259 | |
260 | if (!vdev->fops->read) | |
261 | return -EINVAL; | |
2877842d HV |
262 | if (vdev->lock && mutex_lock_interruptible(vdev->lock)) |
263 | return -ERESTARTSYS; | |
ee6869af HV |
264 | if (video_is_registered(vdev)) |
265 | ret = vdev->fops->read(filp, buf, sz, off); | |
266 | if (vdev->lock) | |
267 | mutex_unlock(vdev->lock); | |
268 | return ret; | |
dc93a70c HV |
269 | } |
270 | ||
271 | static ssize_t v4l2_write(struct file *filp, const char __user *buf, | |
272 | size_t sz, loff_t *off) | |
273 | { | |
274 | struct video_device *vdev = video_devdata(filp); | |
2877842d | 275 | int ret = -ENODEV; |
dc93a70c HV |
276 | |
277 | if (!vdev->fops->write) | |
278 | return -EINVAL; | |
2877842d HV |
279 | if (vdev->lock && mutex_lock_interruptible(vdev->lock)) |
280 | return -ERESTARTSYS; | |
ee6869af HV |
281 | if (video_is_registered(vdev)) |
282 | ret = vdev->fops->write(filp, buf, sz, off); | |
283 | if (vdev->lock) | |
284 | mutex_unlock(vdev->lock); | |
285 | return ret; | |
dc93a70c HV |
286 | } |
287 | ||
288 | static unsigned int v4l2_poll(struct file *filp, struct poll_table_struct *poll) | |
289 | { | |
290 | struct video_device *vdev = video_devdata(filp); | |
2877842d | 291 | int ret = POLLERR | POLLHUP; |
ee6869af HV |
292 | |
293 | if (!vdev->fops->poll) | |
2877842d | 294 | return DEFAULT_POLLMASK; |
ee6869af HV |
295 | if (vdev->lock) |
296 | mutex_lock(vdev->lock); | |
297 | if (video_is_registered(vdev)) | |
298 | ret = vdev->fops->poll(filp, poll); | |
299 | if (vdev->lock) | |
300 | mutex_unlock(vdev->lock); | |
301 | return ret; | |
dc93a70c HV |
302 | } |
303 | ||
86a5ef7d | 304 | static long v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) |
dc93a70c HV |
305 | { |
306 | struct video_device *vdev = video_devdata(filp); | |
72420630 | 307 | int ret = -ENODEV; |
dc93a70c | 308 | |
86a5ef7d | 309 | if (vdev->fops->unlocked_ioctl) { |
2877842d HV |
310 | if (vdev->lock && mutex_lock_interruptible(vdev->lock)) |
311 | return -ERESTARTSYS; | |
72420630 MCC |
312 | if (video_is_registered(vdev)) |
313 | ret = vdev->fops->unlocked_ioctl(filp, cmd, arg); | |
ee6869af HV |
314 | if (vdev->lock) |
315 | mutex_unlock(vdev->lock); | |
86a5ef7d | 316 | } else if (vdev->fops->ioctl) { |
879aa24d HV |
317 | /* This code path is a replacement for the BKL. It is a major |
318 | * hack but it will have to do for those drivers that are not | |
319 | * yet converted to use unlocked_ioctl. | |
320 | * | |
321 | * There are two options: if the driver implements struct | |
322 | * v4l2_device, then the lock defined there is used to | |
323 | * serialize the ioctls. Otherwise the v4l2 core lock defined | |
324 | * below is used. This lock is really bad since it serializes | |
325 | * completely independent devices. | |
326 | * | |
327 | * Both variants suffer from the same problem: if the driver | |
328 | * sleeps, then it blocks all ioctls since the lock is still | |
329 | * held. This is very common for VIDIOC_DQBUF since that | |
330 | * normally waits for a frame to arrive. As a result any other | |
331 | * ioctl calls will proceed very, very slowly since each call | |
332 | * will have to wait for the VIDIOC_QBUF to finish. Things that | |
333 | * should take 0.01s may now take 10-20 seconds. | |
334 | * | |
335 | * The workaround is to *not* take the lock for VIDIOC_DQBUF. | |
336 | * This actually works OK for videobuf-based drivers, since | |
337 | * videobuf will take its own internal lock. | |
338 | */ | |
0edf2e5e | 339 | static DEFINE_MUTEX(v4l2_ioctl_mutex); |
879aa24d HV |
340 | struct mutex *m = vdev->v4l2_dev ? |
341 | &vdev->v4l2_dev->ioctl_lock : &v4l2_ioctl_mutex; | |
0edf2e5e | 342 | |
879aa24d HV |
343 | if (cmd != VIDIOC_DQBUF && mutex_lock_interruptible(m)) |
344 | return -ERESTARTSYS; | |
72420630 MCC |
345 | if (video_is_registered(vdev)) |
346 | ret = vdev->fops->ioctl(filp, cmd, arg); | |
879aa24d HV |
347 | if (cmd != VIDIOC_DQBUF) |
348 | mutex_unlock(m); | |
86a5ef7d AB |
349 | } else |
350 | ret = -ENOTTY; | |
dc93a70c | 351 | |
86a5ef7d | 352 | return ret; |
dc93a70c HV |
353 | } |
354 | ||
dc93a70c HV |
355 | static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm) |
356 | { | |
357 | struct video_device *vdev = video_devdata(filp); | |
ee6869af HV |
358 | int ret = -ENODEV; |
359 | ||
360 | if (!vdev->fops->mmap) | |
361 | return ret; | |
2877842d HV |
362 | if (vdev->lock && mutex_lock_interruptible(vdev->lock)) |
363 | return -ERESTARTSYS; | |
ee6869af HV |
364 | if (video_is_registered(vdev)) |
365 | ret = vdev->fops->mmap(filp, vm); | |
366 | if (vdev->lock) | |
367 | mutex_unlock(vdev->lock); | |
368 | return ret; | |
dc93a70c HV |
369 | } |
370 | ||
371 | /* Override for the open function */ | |
372 | static int v4l2_open(struct inode *inode, struct file *filp) | |
373 | { | |
374 | struct video_device *vdev; | |
2c0ab67b LP |
375 | #if defined(CONFIG_MEDIA_CONTROLLER) |
376 | struct media_entity *entity = NULL; | |
377 | #endif | |
65d9ff9c | 378 | int ret = 0; |
dc93a70c HV |
379 | |
380 | /* Check if the video device is available */ | |
381 | mutex_lock(&videodev_lock); | |
382 | vdev = video_devdata(filp); | |
ee6869af | 383 | /* return ENODEV if the video device has already been removed. */ |
ca9afe6f | 384 | if (vdev == NULL || !video_is_registered(vdev)) { |
dc93a70c HV |
385 | mutex_unlock(&videodev_lock); |
386 | return -ENODEV; | |
387 | } | |
388 | /* and increase the device refcount */ | |
389 | video_get(vdev); | |
390 | mutex_unlock(&videodev_lock); | |
2c0ab67b LP |
391 | #if defined(CONFIG_MEDIA_CONTROLLER) |
392 | if (vdev->v4l2_dev && vdev->v4l2_dev->mdev) { | |
393 | entity = media_entity_get(&vdev->entity); | |
394 | if (!entity) { | |
395 | ret = -EBUSY; | |
396 | video_put(vdev); | |
397 | return ret; | |
398 | } | |
399 | } | |
400 | #endif | |
ee6869af | 401 | if (vdev->fops->open) { |
2877842d HV |
402 | if (vdev->lock && mutex_lock_interruptible(vdev->lock)) { |
403 | ret = -ERESTARTSYS; | |
404 | goto err; | |
405 | } | |
ee6869af HV |
406 | if (video_is_registered(vdev)) |
407 | ret = vdev->fops->open(filp); | |
408 | else | |
409 | ret = -ENODEV; | |
410 | if (vdev->lock) | |
411 | mutex_unlock(vdev->lock); | |
412 | } | |
65d9ff9c | 413 | |
2877842d | 414 | err: |
dc93a70c | 415 | /* decrease the refcount in case of an error */ |
2c0ab67b LP |
416 | if (ret) { |
417 | #if defined(CONFIG_MEDIA_CONTROLLER) | |
418 | if (vdev->v4l2_dev && vdev->v4l2_dev->mdev) | |
419 | media_entity_put(entity); | |
420 | #endif | |
dc93a70c | 421 | video_put(vdev); |
2c0ab67b | 422 | } |
dc93a70c HV |
423 | return ret; |
424 | } | |
425 | ||
426 | /* Override for the release function */ | |
427 | static int v4l2_release(struct inode *inode, struct file *filp) | |
428 | { | |
429 | struct video_device *vdev = video_devdata(filp); | |
65d9ff9c HV |
430 | int ret = 0; |
431 | ||
ee6869af HV |
432 | if (vdev->fops->release) { |
433 | if (vdev->lock) | |
434 | mutex_lock(vdev->lock); | |
65d9ff9c | 435 | vdev->fops->release(filp); |
ee6869af HV |
436 | if (vdev->lock) |
437 | mutex_unlock(vdev->lock); | |
438 | } | |
2c0ab67b LP |
439 | #if defined(CONFIG_MEDIA_CONTROLLER) |
440 | if (vdev->v4l2_dev && vdev->v4l2_dev->mdev) | |
441 | media_entity_put(&vdev->entity); | |
442 | #endif | |
dc93a70c HV |
443 | /* decrease the refcount unconditionally since the release() |
444 | return value is ignored. */ | |
445 | video_put(vdev); | |
446 | return ret; | |
447 | } | |
448 | ||
dc93a70c HV |
449 | static const struct file_operations v4l2_fops = { |
450 | .owner = THIS_MODULE, | |
451 | .read = v4l2_read, | |
452 | .write = v4l2_write, | |
453 | .open = v4l2_open, | |
454 | .mmap = v4l2_mmap, | |
86a5ef7d | 455 | .unlocked_ioctl = v4l2_ioctl, |
dc93a70c | 456 | #ifdef CONFIG_COMPAT |
9bb7cde7 | 457 | .compat_ioctl = v4l2_compat_ioctl32, |
dc93a70c HV |
458 | #endif |
459 | .release = v4l2_release, | |
460 | .poll = v4l2_poll, | |
461 | .llseek = no_llseek, | |
462 | }; | |
463 | ||
27a5e6d3 | 464 | /** |
7ae0cd9b | 465 | * get_index - assign stream index number based on parent device |
dc93a70c | 466 | * @vdev: video_device to assign index number to, vdev->parent should be assigned |
27a5e6d3 | 467 | * |
dc93a70c | 468 | * Note that when this is called the new device has not yet been registered |
7ae0cd9b | 469 | * in the video_device array, but it was able to obtain a minor number. |
27a5e6d3 | 470 | * |
7ae0cd9b HV |
471 | * This means that we can always obtain a free stream index number since |
472 | * the worst case scenario is that there are VIDEO_NUM_DEVICES - 1 slots in | |
473 | * use of the video_device array. | |
474 | * | |
475 | * Returns a free index number. | |
27a5e6d3 | 476 | */ |
7ae0cd9b | 477 | static int get_index(struct video_device *vdev) |
27a5e6d3 | 478 | { |
775a05dd HV |
479 | /* This can be static since this function is called with the global |
480 | videodev_lock held. */ | |
481 | static DECLARE_BITMAP(used, VIDEO_NUM_DEVICES); | |
27a5e6d3 HV |
482 | int i; |
483 | ||
7ae0cd9b | 484 | /* Some drivers do not set the parent. In that case always return 0. */ |
806e5b7c | 485 | if (vdev->parent == NULL) |
7ae0cd9b | 486 | return 0; |
775a05dd HV |
487 | |
488 | bitmap_zero(used, VIDEO_NUM_DEVICES); | |
806e5b7c | 489 | |
27a5e6d3 HV |
490 | for (i = 0; i < VIDEO_NUM_DEVICES; i++) { |
491 | if (video_device[i] != NULL && | |
5e85e732 | 492 | video_device[i]->parent == vdev->parent) { |
775a05dd | 493 | set_bit(video_device[i]->index, used); |
27a5e6d3 HV |
494 | } |
495 | } | |
496 | ||
7ae0cd9b | 497 | return find_first_zero_bit(used, VIDEO_NUM_DEVICES); |
27a5e6d3 HV |
498 | } |
499 | ||
27a5e6d3 | 500 | /** |
2096a5dc | 501 | * __video_register_device - register video4linux devices |
dc93a70c | 502 | * @vdev: video device structure we want to register |
27a5e6d3 | 503 | * @type: type of device to register |
22e22125 | 504 | * @nr: which device node number (0 == /dev/video0, 1 == /dev/video1, ... |
27a5e6d3 | 505 | * -1 == first free) |
6b5270d2 HV |
506 | * @warn_if_nr_in_use: warn if the desired device node number |
507 | * was already in use and another number was chosen instead. | |
2096a5dc | 508 | * @owner: module that owns the video device node |
27a5e6d3 | 509 | * |
22e22125 HV |
510 | * The registration code assigns minor numbers and device node numbers |
511 | * based on the requested type and registers the new device node with | |
512 | * the kernel. | |
46b63377 HV |
513 | * |
514 | * This function assumes that struct video_device was zeroed when it | |
515 | * was allocated and does not contain any stale date. | |
516 | * | |
22e22125 HV |
517 | * An error is returned if no free minor or device node number could be |
518 | * found, or if the registration of the device node failed. | |
27a5e6d3 HV |
519 | * |
520 | * Zero is returned on success. | |
521 | * | |
522 | * Valid types are | |
523 | * | |
524 | * %VFL_TYPE_GRABBER - A frame grabber | |
525 | * | |
27a5e6d3 HV |
526 | * %VFL_TYPE_VBI - Vertical blank data (undecoded) |
527 | * | |
528 | * %VFL_TYPE_RADIO - A radio card | |
2096a5dc LP |
529 | * |
530 | * %VFL_TYPE_SUBDEV - A subdevice | |
27a5e6d3 | 531 | */ |
2096a5dc LP |
532 | int __video_register_device(struct video_device *vdev, int type, int nr, |
533 | int warn_if_nr_in_use, struct module *owner) | |
27a5e6d3 HV |
534 | { |
535 | int i = 0; | |
27a5e6d3 | 536 | int ret; |
dd89601d HV |
537 | int minor_offset = 0; |
538 | int minor_cnt = VIDEO_NUM_DEVICES; | |
539 | const char *name_base; | |
27a5e6d3 | 540 | |
dc93a70c HV |
541 | /* A minor value of -1 marks this video device as never |
542 | having been registered */ | |
428c8d19 | 543 | vdev->minor = -1; |
ee7aa9f8 | 544 | |
dc93a70c | 545 | /* the release callback MUST be present */ |
428c8d19 TP |
546 | WARN_ON(!vdev->release); |
547 | if (!vdev->release) | |
f3b9f50e HK |
548 | return -EINVAL; |
549 | ||
1babcb46 SA |
550 | /* v4l2_fh support */ |
551 | spin_lock_init(&vdev->fh_lock); | |
552 | INIT_LIST_HEAD(&vdev->fh_list); | |
553 | ||
dc93a70c | 554 | /* Part 1: check device type */ |
27a5e6d3 HV |
555 | switch (type) { |
556 | case VFL_TYPE_GRABBER: | |
27a5e6d3 HV |
557 | name_base = "video"; |
558 | break; | |
27a5e6d3 | 559 | case VFL_TYPE_VBI: |
27a5e6d3 HV |
560 | name_base = "vbi"; |
561 | break; | |
562 | case VFL_TYPE_RADIO: | |
27a5e6d3 HV |
563 | name_base = "radio"; |
564 | break; | |
2096a5dc LP |
565 | case VFL_TYPE_SUBDEV: |
566 | name_base = "v4l-subdev"; | |
567 | break; | |
27a5e6d3 HV |
568 | default: |
569 | printk(KERN_ERR "%s called with unknown type: %d\n", | |
570 | __func__, type); | |
46f2c21c | 571 | return -EINVAL; |
27a5e6d3 HV |
572 | } |
573 | ||
dc93a70c HV |
574 | vdev->vfl_type = type; |
575 | vdev->cdev = NULL; | |
11bbc1ca HV |
576 | if (vdev->v4l2_dev) { |
577 | if (vdev->v4l2_dev->dev) | |
578 | vdev->parent = vdev->v4l2_dev->dev; | |
579 | if (vdev->ctrl_handler == NULL) | |
580 | vdev->ctrl_handler = vdev->v4l2_dev->ctrl_handler; | |
0f62fd6a HV |
581 | /* If the prio state pointer is NULL, and if the driver doesn't |
582 | handle priorities itself, then use the v4l2_device prio | |
583 | state. */ | |
584 | if (vdev->prio == NULL && vdev->ioctl_ops && | |
585 | vdev->ioctl_ops->vidioc_s_priority == NULL) | |
586 | vdev->prio = &vdev->v4l2_dev->prio; | |
11bbc1ca | 587 | } |
dd89601d | 588 | |
22e22125 | 589 | /* Part 2: find a free minor, device node number and device index. */ |
dd89601d HV |
590 | #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES |
591 | /* Keep the ranges for the first four types for historical | |
592 | * reasons. | |
593 | * Newer devices (not yet in place) should use the range | |
594 | * of 128-191 and just pick the first free minor there | |
595 | * (new style). */ | |
596 | switch (type) { | |
597 | case VFL_TYPE_GRABBER: | |
598 | minor_offset = 0; | |
599 | minor_cnt = 64; | |
600 | break; | |
601 | case VFL_TYPE_RADIO: | |
602 | minor_offset = 64; | |
603 | minor_cnt = 64; | |
604 | break; | |
dd89601d HV |
605 | case VFL_TYPE_VBI: |
606 | minor_offset = 224; | |
607 | minor_cnt = 32; | |
608 | break; | |
609 | default: | |
610 | minor_offset = 128; | |
611 | minor_cnt = 64; | |
612 | break; | |
613 | } | |
614 | #endif | |
615 | ||
22e22125 | 616 | /* Pick a device node number */ |
27a5e6d3 | 617 | mutex_lock(&videodev_lock); |
5062cb70 | 618 | nr = devnode_find(vdev, nr == -1 ? 0 : nr, minor_cnt); |
dd89601d | 619 | if (nr == minor_cnt) |
5062cb70 | 620 | nr = devnode_find(vdev, 0, minor_cnt); |
dd89601d | 621 | if (nr == minor_cnt) { |
22e22125 | 622 | printk(KERN_ERR "could not get a free device node number\n"); |
dd89601d HV |
623 | mutex_unlock(&videodev_lock); |
624 | return -ENFILE; | |
27a5e6d3 | 625 | } |
dd89601d | 626 | #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES |
22e22125 | 627 | /* 1-on-1 mapping of device node number to minor number */ |
dd89601d HV |
628 | i = nr; |
629 | #else | |
22e22125 HV |
630 | /* The device node number and minor numbers are independent, so |
631 | we just find the first free minor number. */ | |
dd89601d HV |
632 | for (i = 0; i < VIDEO_NUM_DEVICES; i++) |
633 | if (video_device[i] == NULL) | |
634 | break; | |
635 | if (i == VIDEO_NUM_DEVICES) { | |
636 | mutex_unlock(&videodev_lock); | |
637 | printk(KERN_ERR "could not get a free minor\n"); | |
638 | return -ENFILE; | |
639 | } | |
640 | #endif | |
dc93a70c HV |
641 | vdev->minor = i + minor_offset; |
642 | vdev->num = nr; | |
5062cb70 HV |
643 | devnode_set(vdev); |
644 | ||
dc93a70c HV |
645 | /* Should not happen since we thought this minor was free */ |
646 | WARN_ON(video_device[vdev->minor] != NULL); | |
7ae0cd9b | 647 | vdev->index = get_index(vdev); |
27a5e6d3 HV |
648 | mutex_unlock(&videodev_lock); |
649 | ||
dc93a70c HV |
650 | /* Part 3: Initialize the character device */ |
651 | vdev->cdev = cdev_alloc(); | |
652 | if (vdev->cdev == NULL) { | |
653 | ret = -ENOMEM; | |
654 | goto cleanup; | |
655 | } | |
86a5ef7d | 656 | vdev->cdev->ops = &v4l2_fops; |
2096a5dc | 657 | vdev->cdev->owner = owner; |
dc93a70c | 658 | ret = cdev_add(vdev->cdev, MKDEV(VIDEO_MAJOR, vdev->minor), 1); |
7f8ecfab HV |
659 | if (ret < 0) { |
660 | printk(KERN_ERR "%s: cdev_add failed\n", __func__); | |
dc93a70c HV |
661 | kfree(vdev->cdev); |
662 | vdev->cdev = NULL; | |
663 | goto cleanup; | |
7f8ecfab | 664 | } |
dc93a70c HV |
665 | |
666 | /* Part 4: register the device with sysfs */ | |
dc93a70c HV |
667 | vdev->dev.class = &video_class; |
668 | vdev->dev.devt = MKDEV(VIDEO_MAJOR, vdev->minor); | |
669 | if (vdev->parent) | |
670 | vdev->dev.parent = vdev->parent; | |
22e22125 | 671 | dev_set_name(&vdev->dev, "%s%d", name_base, vdev->num); |
dc93a70c | 672 | ret = device_register(&vdev->dev); |
27a5e6d3 HV |
673 | if (ret < 0) { |
674 | printk(KERN_ERR "%s: device_register failed\n", __func__); | |
dc93a70c | 675 | goto cleanup; |
27a5e6d3 | 676 | } |
dc93a70c HV |
677 | /* Register the release callback that will be called when the last |
678 | reference to the device goes away. */ | |
679 | vdev->dev.release = v4l2_device_release; | |
27a5e6d3 | 680 | |
6b5270d2 | 681 | if (nr != -1 && nr != vdev->num && warn_if_nr_in_use) |
eac8ea53 LP |
682 | printk(KERN_WARNING "%s: requested %s%d, got %s\n", __func__, |
683 | name_base, nr, video_device_node_name(vdev)); | |
bedf8bcf HV |
684 | |
685 | /* Increase v4l2_device refcount */ | |
686 | if (vdev->v4l2_dev) | |
687 | v4l2_device_get(vdev->v4l2_dev); | |
688 | ||
2c0ab67b LP |
689 | #if defined(CONFIG_MEDIA_CONTROLLER) |
690 | /* Part 5: Register the entity. */ | |
691 | if (vdev->v4l2_dev && vdev->v4l2_dev->mdev) { | |
692 | vdev->entity.type = MEDIA_ENT_T_DEVNODE_V4L; | |
693 | vdev->entity.name = vdev->name; | |
694 | vdev->entity.v4l.major = VIDEO_MAJOR; | |
695 | vdev->entity.v4l.minor = vdev->minor; | |
696 | ret = media_device_register_entity(vdev->v4l2_dev->mdev, | |
697 | &vdev->entity); | |
698 | if (ret < 0) | |
699 | printk(KERN_WARNING | |
700 | "%s: media_device_register_entity failed\n", | |
701 | __func__); | |
702 | } | |
703 | #endif | |
704 | /* Part 6: Activate this minor. The char device can now be used. */ | |
957b4aa9 | 705 | set_bit(V4L2_FL_REGISTERED, &vdev->flags); |
dc93a70c HV |
706 | mutex_lock(&videodev_lock); |
707 | video_device[vdev->minor] = vdev; | |
708 | mutex_unlock(&videodev_lock); | |
2c0ab67b | 709 | |
dc93a70c | 710 | return 0; |
7f8ecfab | 711 | |
dc93a70c | 712 | cleanup: |
27a5e6d3 | 713 | mutex_lock(&videodev_lock); |
dc93a70c HV |
714 | if (vdev->cdev) |
715 | cdev_del(vdev->cdev); | |
5062cb70 | 716 | devnode_clear(vdev); |
27a5e6d3 | 717 | mutex_unlock(&videodev_lock); |
dc93a70c HV |
718 | /* Mark this video device as never having been registered. */ |
719 | vdev->minor = -1; | |
27a5e6d3 HV |
720 | return ret; |
721 | } | |
2096a5dc | 722 | EXPORT_SYMBOL(__video_register_device); |
6b5270d2 | 723 | |
27a5e6d3 HV |
724 | /** |
725 | * video_unregister_device - unregister a video4linux device | |
dc93a70c | 726 | * @vdev: the device to unregister |
27a5e6d3 | 727 | * |
dc93a70c HV |
728 | * This unregisters the passed device. Future open calls will |
729 | * be met with errors. | |
27a5e6d3 | 730 | */ |
dc93a70c | 731 | void video_unregister_device(struct video_device *vdev) |
27a5e6d3 | 732 | { |
dc93a70c | 733 | /* Check if vdev was ever registered at all */ |
957b4aa9 | 734 | if (!vdev || !video_is_registered(vdev)) |
dc93a70c HV |
735 | return; |
736 | ||
2c0ab67b LP |
737 | #if defined(CONFIG_MEDIA_CONTROLLER) |
738 | if (vdev->v4l2_dev && vdev->v4l2_dev->mdev) | |
739 | media_device_unregister_entity(&vdev->entity); | |
740 | #endif | |
741 | ||
ca9afe6f HV |
742 | mutex_lock(&videodev_lock); |
743 | /* This must be in a critical section to prevent a race with v4l2_open. | |
744 | * Once this bit has been cleared video_get may never be called again. | |
745 | */ | |
957b4aa9 | 746 | clear_bit(V4L2_FL_REGISTERED, &vdev->flags); |
ca9afe6f | 747 | mutex_unlock(&videodev_lock); |
dc93a70c | 748 | device_unregister(&vdev->dev); |
27a5e6d3 HV |
749 | } |
750 | EXPORT_SYMBOL(video_unregister_device); | |
751 | ||
27a5e6d3 HV |
752 | /* |
753 | * Initialise video for linux | |
754 | */ | |
27a5e6d3 HV |
755 | static int __init videodev_init(void) |
756 | { | |
7f8ecfab | 757 | dev_t dev = MKDEV(VIDEO_MAJOR, 0); |
27a5e6d3 HV |
758 | int ret; |
759 | ||
760 | printk(KERN_INFO "Linux video capture interface: v2.00\n"); | |
7f8ecfab HV |
761 | ret = register_chrdev_region(dev, VIDEO_NUM_DEVICES, VIDEO_NAME); |
762 | if (ret < 0) { | |
763 | printk(KERN_WARNING "videodev: unable to get major %d\n", | |
764 | VIDEO_MAJOR); | |
765 | return ret; | |
27a5e6d3 HV |
766 | } |
767 | ||
768 | ret = class_register(&video_class); | |
769 | if (ret < 0) { | |
7f8ecfab | 770 | unregister_chrdev_region(dev, VIDEO_NUM_DEVICES); |
27a5e6d3 HV |
771 | printk(KERN_WARNING "video_dev: class_register failed\n"); |
772 | return -EIO; | |
773 | } | |
774 | ||
775 | return 0; | |
776 | } | |
777 | ||
778 | static void __exit videodev_exit(void) | |
779 | { | |
7f8ecfab HV |
780 | dev_t dev = MKDEV(VIDEO_MAJOR, 0); |
781 | ||
27a5e6d3 | 782 | class_unregister(&video_class); |
7f8ecfab | 783 | unregister_chrdev_region(dev, VIDEO_NUM_DEVICES); |
27a5e6d3 HV |
784 | } |
785 | ||
786 | module_init(videodev_init) | |
787 | module_exit(videodev_exit) | |
788 | ||
789 | MODULE_AUTHOR("Alan Cox, Mauro Carvalho Chehab <mchehab@infradead.org>"); | |
790 | MODULE_DESCRIPTION("Device registrar for Video4Linux drivers v2"); | |
791 | MODULE_LICENSE("GPL"); | |
cbb72b0f | 792 | MODULE_ALIAS_CHARDEV_MAJOR(VIDEO_MAJOR); |
27a5e6d3 HV |
793 | |
794 | ||
795 | /* | |
796 | * Local variables: | |
797 | * c-basic-offset: 8 | |
798 | * End: | |
799 | */ |