Commit | Line | Data |
---|---|---|
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 | 28 | #include <asm/uaccess.h> |
27a5e6d3 HV |
29 | |
30 | #include <media/v4l2-common.h> | |
9bea3514 | 31 | #include <media/v4l2-device.h> |
bec43661 | 32 | #include <media/v4l2-ioctl.h> |
27a5e6d3 HV |
33 | |
34 | #define VIDEO_NUM_DEVICES 256 | |
35 | #define VIDEO_NAME "video4linux" | |
36 | ||
37 | /* | |
38 | * sysfs stuff | |
39 | */ | |
40 | ||
41 | static ssize_t show_index(struct device *cd, | |
42 | struct device_attribute *attr, char *buf) | |
43 | { | |
dc93a70c | 44 | struct video_device *vdev = to_video_device(cd); |
bfa8a273 | 45 | |
dc93a70c | 46 | return sprintf(buf, "%i\n", vdev->index); |
27a5e6d3 HV |
47 | } |
48 | ||
49 | static ssize_t show_name(struct device *cd, | |
50 | struct device_attribute *attr, char *buf) | |
51 | { | |
dc93a70c | 52 | struct video_device *vdev = to_video_device(cd); |
bfa8a273 | 53 | |
dc93a70c | 54 | return sprintf(buf, "%.*s\n", (int)sizeof(vdev->name), vdev->name); |
27a5e6d3 HV |
55 | } |
56 | ||
57 | static struct device_attribute video_device_attrs[] = { | |
58 | __ATTR(name, S_IRUGO, show_name, NULL), | |
59 | __ATTR(index, S_IRUGO, show_index, NULL), | |
60 | __ATTR_NULL | |
61 | }; | |
62 | ||
7f8ecfab HV |
63 | /* |
64 | * Active devices | |
65 | */ | |
66 | static struct video_device *video_device[VIDEO_NUM_DEVICES]; | |
67 | static DEFINE_MUTEX(videodev_lock); | |
22e22125 | 68 | static DECLARE_BITMAP(devnode_nums[VFL_TYPE_MAX], VIDEO_NUM_DEVICES); |
7f8ecfab | 69 | |
5062cb70 HV |
70 | /* Device node utility functions */ |
71 | ||
72 | /* Note: these utility functions all assume that vfl_type is in the range | |
73 | [0, VFL_TYPE_MAX-1]. */ | |
74 | ||
75 | #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES | |
76 | /* Return the bitmap corresponding to vfl_type. */ | |
77 | static inline unsigned long *devnode_bits(int vfl_type) | |
78 | { | |
79 | /* Any types not assigned to fixed minor ranges must be mapped to | |
80 | one single bitmap for the purposes of finding a free node number | |
81 | since all those unassigned types use the same minor range. */ | |
226c0eea | 82 | int idx = (vfl_type > VFL_TYPE_RADIO) ? VFL_TYPE_MAX - 1 : vfl_type; |
5062cb70 HV |
83 | |
84 | return devnode_nums[idx]; | |
85 | } | |
86 | #else | |
87 | /* Return the bitmap corresponding to vfl_type. */ | |
88 | static inline unsigned long *devnode_bits(int vfl_type) | |
89 | { | |
90 | return devnode_nums[vfl_type]; | |
91 | } | |
92 | #endif | |
93 | ||
94 | /* Mark device node number vdev->num as used */ | |
95 | static inline void devnode_set(struct video_device *vdev) | |
96 | { | |
97 | set_bit(vdev->num, devnode_bits(vdev->vfl_type)); | |
98 | } | |
99 | ||
100 | /* Mark device node number vdev->num as unused */ | |
101 | static inline void devnode_clear(struct video_device *vdev) | |
102 | { | |
103 | clear_bit(vdev->num, devnode_bits(vdev->vfl_type)); | |
104 | } | |
105 | ||
106 | /* Try to find a free device node number in the range [from, to> */ | |
107 | static inline int devnode_find(struct video_device *vdev, int from, int to) | |
108 | { | |
109 | return find_next_zero_bit(devnode_bits(vdev->vfl_type), to, from); | |
110 | } | |
111 | ||
27a5e6d3 HV |
112 | struct video_device *video_device_alloc(void) |
113 | { | |
bfa8a273 | 114 | return kzalloc(sizeof(struct video_device), GFP_KERNEL); |
27a5e6d3 HV |
115 | } |
116 | EXPORT_SYMBOL(video_device_alloc); | |
117 | ||
dc93a70c | 118 | void video_device_release(struct video_device *vdev) |
27a5e6d3 | 119 | { |
dc93a70c | 120 | kfree(vdev); |
27a5e6d3 HV |
121 | } |
122 | EXPORT_SYMBOL(video_device_release); | |
123 | ||
dc93a70c | 124 | void video_device_release_empty(struct video_device *vdev) |
f9e86b5e HV |
125 | { |
126 | /* Do nothing */ | |
127 | /* Only valid when the video_device struct is a static. */ | |
128 | } | |
129 | EXPORT_SYMBOL(video_device_release_empty); | |
130 | ||
dc93a70c | 131 | static inline void video_get(struct video_device *vdev) |
7f8ecfab | 132 | { |
dc93a70c HV |
133 | get_device(&vdev->dev); |
134 | } | |
135 | ||
136 | static inline void video_put(struct video_device *vdev) | |
137 | { | |
138 | put_device(&vdev->dev); | |
139 | } | |
140 | ||
141 | /* Called when the last user of the video device exits. */ | |
142 | static void v4l2_device_release(struct device *cd) | |
143 | { | |
144 | struct video_device *vdev = to_video_device(cd); | |
bedf8bcf | 145 | struct v4l2_device *v4l2_dev = vdev->v4l2_dev; |
7f8ecfab HV |
146 | |
147 | mutex_lock(&videodev_lock); | |
1fc2b5f7 | 148 | if (WARN_ON(video_device[vdev->minor] != vdev)) { |
dc93a70c | 149 | /* should not happen */ |
1fc2b5f7 | 150 | mutex_unlock(&videodev_lock); |
6ea9a182 HV |
151 | return; |
152 | } | |
7f8ecfab HV |
153 | |
154 | /* Free up this device for reuse */ | |
dc93a70c | 155 | video_device[vdev->minor] = NULL; |
7f8ecfab | 156 | |
dc93a70c HV |
157 | /* Delete the cdev on this minor as well */ |
158 | cdev_del(vdev->cdev); | |
159 | /* Just in case some driver tries to access this from | |
160 | the release() callback. */ | |
161 | vdev->cdev = NULL; | |
7f8ecfab | 162 | |
22e22125 | 163 | /* Mark device node number as free */ |
5062cb70 | 164 | devnode_clear(vdev); |
7f8ecfab | 165 | |
dc93a70c | 166 | mutex_unlock(&videodev_lock); |
27a5e6d3 | 167 | |
c064b8ea | 168 | #if defined(CONFIG_MEDIA_CONTROLLER) |
1fc2b5f7 | 169 | if (v4l2_dev && v4l2_dev->mdev && |
c064b8ea LP |
170 | vdev->vfl_type != VFL_TYPE_SUBDEV) |
171 | media_device_unregister_entity(&vdev->entity); | |
172 | #endif | |
173 | ||
8280b662 HV |
174 | /* Do not call v4l2_device_put if there is no release callback set. |
175 | * Drivers that have no v4l2_device release callback might free the | |
176 | * v4l2_dev instance in the video_device release callback below, so we | |
177 | * must perform this check here. | |
178 | * | |
179 | * TODO: In the long run all drivers that use v4l2_device should use the | |
180 | * v4l2_device release callback. This check will then be unnecessary. | |
181 | */ | |
e58fced2 | 182 | if (v4l2_dev && v4l2_dev->release == NULL) |
8280b662 HV |
183 | v4l2_dev = NULL; |
184 | ||
dc93a70c HV |
185 | /* Release video_device and perform other |
186 | cleanups as needed. */ | |
187 | vdev->release(vdev); | |
bedf8bcf HV |
188 | |
189 | /* Decrease v4l2_device refcount */ | |
190 | if (v4l2_dev) | |
191 | v4l2_device_put(v4l2_dev); | |
27a5e6d3 HV |
192 | } |
193 | ||
194 | static struct class video_class = { | |
195 | .name = VIDEO_NAME, | |
196 | .dev_attrs = video_device_attrs, | |
27a5e6d3 HV |
197 | }; |
198 | ||
27a5e6d3 HV |
199 | struct video_device *video_devdata(struct file *file) |
200 | { | |
201 | return video_device[iminor(file->f_path.dentry->d_inode)]; | |
202 | } | |
203 | EXPORT_SYMBOL(video_devdata); | |
204 | ||
02265493 HV |
205 | |
206 | /* Priority handling */ | |
207 | ||
208 | static inline bool prio_is_valid(enum v4l2_priority prio) | |
209 | { | |
210 | return prio == V4L2_PRIORITY_BACKGROUND || | |
211 | prio == V4L2_PRIORITY_INTERACTIVE || | |
212 | prio == V4L2_PRIORITY_RECORD; | |
213 | } | |
214 | ||
215 | void v4l2_prio_init(struct v4l2_prio_state *global) | |
216 | { | |
217 | memset(global, 0, sizeof(*global)); | |
218 | } | |
219 | EXPORT_SYMBOL(v4l2_prio_init); | |
220 | ||
221 | int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local, | |
222 | enum v4l2_priority new) | |
223 | { | |
224 | if (!prio_is_valid(new)) | |
225 | return -EINVAL; | |
226 | if (*local == new) | |
227 | return 0; | |
228 | ||
229 | atomic_inc(&global->prios[new]); | |
230 | if (prio_is_valid(*local)) | |
231 | atomic_dec(&global->prios[*local]); | |
232 | *local = new; | |
233 | return 0; | |
234 | } | |
235 | EXPORT_SYMBOL(v4l2_prio_change); | |
236 | ||
237 | void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local) | |
238 | { | |
239 | v4l2_prio_change(global, local, V4L2_PRIORITY_DEFAULT); | |
240 | } | |
241 | EXPORT_SYMBOL(v4l2_prio_open); | |
242 | ||
243 | void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local) | |
244 | { | |
245 | if (prio_is_valid(local)) | |
246 | atomic_dec(&global->prios[local]); | |
247 | } | |
248 | EXPORT_SYMBOL(v4l2_prio_close); | |
249 | ||
250 | enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global) | |
251 | { | |
252 | if (atomic_read(&global->prios[V4L2_PRIORITY_RECORD]) > 0) | |
253 | return V4L2_PRIORITY_RECORD; | |
254 | if (atomic_read(&global->prios[V4L2_PRIORITY_INTERACTIVE]) > 0) | |
255 | return V4L2_PRIORITY_INTERACTIVE; | |
256 | if (atomic_read(&global->prios[V4L2_PRIORITY_BACKGROUND]) > 0) | |
257 | return V4L2_PRIORITY_BACKGROUND; | |
258 | return V4L2_PRIORITY_UNSET; | |
259 | } | |
260 | EXPORT_SYMBOL(v4l2_prio_max); | |
261 | ||
262 | int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local) | |
263 | { | |
264 | return (local < v4l2_prio_max(global)) ? -EBUSY : 0; | |
265 | } | |
266 | EXPORT_SYMBOL(v4l2_prio_check); | |
267 | ||
268 | ||
dc93a70c HV |
269 | static ssize_t v4l2_read(struct file *filp, char __user *buf, |
270 | size_t sz, loff_t *off) | |
271 | { | |
272 | struct video_device *vdev = video_devdata(filp); | |
2877842d | 273 | int ret = -ENODEV; |
dc93a70c HV |
274 | |
275 | if (!vdev->fops->read) | |
276 | return -EINVAL; | |
2877842d HV |
277 | if (vdev->lock && mutex_lock_interruptible(vdev->lock)) |
278 | return -ERESTARTSYS; | |
ee6869af HV |
279 | if (video_is_registered(vdev)) |
280 | ret = vdev->fops->read(filp, buf, sz, off); | |
281 | if (vdev->lock) | |
282 | mutex_unlock(vdev->lock); | |
283 | return ret; | |
dc93a70c HV |
284 | } |
285 | ||
286 | static ssize_t v4l2_write(struct file *filp, const char __user *buf, | |
287 | size_t sz, loff_t *off) | |
288 | { | |
289 | struct video_device *vdev = video_devdata(filp); | |
2877842d | 290 | int ret = -ENODEV; |
dc93a70c HV |
291 | |
292 | if (!vdev->fops->write) | |
293 | return -EINVAL; | |
2877842d HV |
294 | if (vdev->lock && mutex_lock_interruptible(vdev->lock)) |
295 | return -ERESTARTSYS; | |
ee6869af HV |
296 | if (video_is_registered(vdev)) |
297 | ret = vdev->fops->write(filp, buf, sz, off); | |
298 | if (vdev->lock) | |
299 | mutex_unlock(vdev->lock); | |
300 | return ret; | |
dc93a70c HV |
301 | } |
302 | ||
303 | static unsigned int v4l2_poll(struct file *filp, struct poll_table_struct *poll) | |
304 | { | |
305 | struct video_device *vdev = video_devdata(filp); | |
2877842d | 306 | int ret = POLLERR | POLLHUP; |
ee6869af HV |
307 | |
308 | if (!vdev->fops->poll) | |
2877842d | 309 | return DEFAULT_POLLMASK; |
ee6869af HV |
310 | if (vdev->lock) |
311 | mutex_lock(vdev->lock); | |
312 | if (video_is_registered(vdev)) | |
313 | ret = vdev->fops->poll(filp, poll); | |
314 | if (vdev->lock) | |
315 | mutex_unlock(vdev->lock); | |
316 | return ret; | |
dc93a70c HV |
317 | } |
318 | ||
86a5ef7d | 319 | static long v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) |
dc93a70c HV |
320 | { |
321 | struct video_device *vdev = video_devdata(filp); | |
72420630 | 322 | int ret = -ENODEV; |
dc93a70c | 323 | |
86a5ef7d | 324 | if (vdev->fops->unlocked_ioctl) { |
2877842d HV |
325 | if (vdev->lock && mutex_lock_interruptible(vdev->lock)) |
326 | return -ERESTARTSYS; | |
72420630 MCC |
327 | if (video_is_registered(vdev)) |
328 | ret = vdev->fops->unlocked_ioctl(filp, cmd, arg); | |
ee6869af HV |
329 | if (vdev->lock) |
330 | mutex_unlock(vdev->lock); | |
86a5ef7d | 331 | } else if (vdev->fops->ioctl) { |
879aa24d HV |
332 | /* This code path is a replacement for the BKL. It is a major |
333 | * hack but it will have to do for those drivers that are not | |
334 | * yet converted to use unlocked_ioctl. | |
335 | * | |
336 | * There are two options: if the driver implements struct | |
337 | * v4l2_device, then the lock defined there is used to | |
338 | * serialize the ioctls. Otherwise the v4l2 core lock defined | |
339 | * below is used. This lock is really bad since it serializes | |
340 | * completely independent devices. | |
341 | * | |
342 | * Both variants suffer from the same problem: if the driver | |
343 | * sleeps, then it blocks all ioctls since the lock is still | |
344 | * held. This is very common for VIDIOC_DQBUF since that | |
345 | * normally waits for a frame to arrive. As a result any other | |
346 | * ioctl calls will proceed very, very slowly since each call | |
347 | * will have to wait for the VIDIOC_QBUF to finish. Things that | |
348 | * should take 0.01s may now take 10-20 seconds. | |
349 | * | |
350 | * The workaround is to *not* take the lock for VIDIOC_DQBUF. | |
351 | * This actually works OK for videobuf-based drivers, since | |
352 | * videobuf will take its own internal lock. | |
353 | */ | |
0edf2e5e | 354 | static DEFINE_MUTEX(v4l2_ioctl_mutex); |
879aa24d HV |
355 | struct mutex *m = vdev->v4l2_dev ? |
356 | &vdev->v4l2_dev->ioctl_lock : &v4l2_ioctl_mutex; | |
0edf2e5e | 357 | |
879aa24d HV |
358 | if (cmd != VIDIOC_DQBUF && mutex_lock_interruptible(m)) |
359 | return -ERESTARTSYS; | |
72420630 MCC |
360 | if (video_is_registered(vdev)) |
361 | ret = vdev->fops->ioctl(filp, cmd, arg); | |
879aa24d HV |
362 | if (cmd != VIDIOC_DQBUF) |
363 | mutex_unlock(m); | |
86a5ef7d AB |
364 | } else |
365 | ret = -ENOTTY; | |
dc93a70c | 366 | |
86a5ef7d | 367 | return ret; |
dc93a70c HV |
368 | } |
369 | ||
ecc6517d BL |
370 | #ifdef CONFIG_MMU |
371 | #define v4l2_get_unmapped_area NULL | |
372 | #else | |
373 | static unsigned long v4l2_get_unmapped_area(struct file *filp, | |
374 | unsigned long addr, unsigned long len, unsigned long pgoff, | |
375 | unsigned long flags) | |
376 | { | |
377 | struct video_device *vdev = video_devdata(filp); | |
378 | ||
379 | if (!vdev->fops->get_unmapped_area) | |
380 | return -ENOSYS; | |
381 | if (!video_is_registered(vdev)) | |
382 | return -ENODEV; | |
383 | return vdev->fops->get_unmapped_area(filp, addr, len, pgoff, flags); | |
384 | } | |
385 | #endif | |
386 | ||
dc93a70c HV |
387 | static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm) |
388 | { | |
389 | struct video_device *vdev = video_devdata(filp); | |
ee6869af HV |
390 | int ret = -ENODEV; |
391 | ||
392 | if (!vdev->fops->mmap) | |
393 | return ret; | |
2877842d HV |
394 | if (vdev->lock && mutex_lock_interruptible(vdev->lock)) |
395 | return -ERESTARTSYS; | |
ee6869af HV |
396 | if (video_is_registered(vdev)) |
397 | ret = vdev->fops->mmap(filp, vm); | |
398 | if (vdev->lock) | |
399 | mutex_unlock(vdev->lock); | |
400 | return ret; | |
dc93a70c HV |
401 | } |
402 | ||
403 | /* Override for the open function */ | |
404 | static int v4l2_open(struct inode *inode, struct file *filp) | |
405 | { | |
406 | struct video_device *vdev; | |
65d9ff9c | 407 | int ret = 0; |
dc93a70c HV |
408 | |
409 | /* Check if the video device is available */ | |
410 | mutex_lock(&videodev_lock); | |
411 | vdev = video_devdata(filp); | |
ee6869af | 412 | /* return ENODEV if the video device has already been removed. */ |
ca9afe6f | 413 | if (vdev == NULL || !video_is_registered(vdev)) { |
dc93a70c HV |
414 | mutex_unlock(&videodev_lock); |
415 | return -ENODEV; | |
416 | } | |
417 | /* and increase the device refcount */ | |
418 | video_get(vdev); | |
419 | mutex_unlock(&videodev_lock); | |
ee6869af | 420 | if (vdev->fops->open) { |
2877842d HV |
421 | if (vdev->lock && mutex_lock_interruptible(vdev->lock)) { |
422 | ret = -ERESTARTSYS; | |
423 | goto err; | |
424 | } | |
ee6869af HV |
425 | if (video_is_registered(vdev)) |
426 | ret = vdev->fops->open(filp); | |
427 | else | |
428 | ret = -ENODEV; | |
429 | if (vdev->lock) | |
430 | mutex_unlock(vdev->lock); | |
431 | } | |
65d9ff9c | 432 | |
2877842d | 433 | err: |
dc93a70c | 434 | /* decrease the refcount in case of an error */ |
c064b8ea | 435 | if (ret) |
dc93a70c HV |
436 | video_put(vdev); |
437 | return ret; | |
438 | } | |
439 | ||
440 | /* Override for the release function */ | |
441 | static int v4l2_release(struct inode *inode, struct file *filp) | |
442 | { | |
443 | struct video_device *vdev = video_devdata(filp); | |
65d9ff9c HV |
444 | int ret = 0; |
445 | ||
ee6869af HV |
446 | if (vdev->fops->release) { |
447 | if (vdev->lock) | |
448 | mutex_lock(vdev->lock); | |
65d9ff9c | 449 | vdev->fops->release(filp); |
ee6869af HV |
450 | if (vdev->lock) |
451 | mutex_unlock(vdev->lock); | |
452 | } | |
dc93a70c HV |
453 | /* decrease the refcount unconditionally since the release() |
454 | return value is ignored. */ | |
455 | video_put(vdev); | |
456 | return ret; | |
457 | } | |
458 | ||
dc93a70c HV |
459 | static const struct file_operations v4l2_fops = { |
460 | .owner = THIS_MODULE, | |
461 | .read = v4l2_read, | |
462 | .write = v4l2_write, | |
463 | .open = v4l2_open, | |
ecc6517d | 464 | .get_unmapped_area = v4l2_get_unmapped_area, |
dc93a70c | 465 | .mmap = v4l2_mmap, |
86a5ef7d | 466 | .unlocked_ioctl = v4l2_ioctl, |
dc93a70c | 467 | #ifdef CONFIG_COMPAT |
9bb7cde7 | 468 | .compat_ioctl = v4l2_compat_ioctl32, |
dc93a70c HV |
469 | #endif |
470 | .release = v4l2_release, | |
471 | .poll = v4l2_poll, | |
472 | .llseek = no_llseek, | |
473 | }; | |
474 | ||
27a5e6d3 | 475 | /** |
7ae0cd9b | 476 | * get_index - assign stream index number based on parent device |
dc93a70c | 477 | * @vdev: video_device to assign index number to, vdev->parent should be assigned |
27a5e6d3 | 478 | * |
dc93a70c | 479 | * Note that when this is called the new device has not yet been registered |
7ae0cd9b | 480 | * in the video_device array, but it was able to obtain a minor number. |
27a5e6d3 | 481 | * |
7ae0cd9b HV |
482 | * This means that we can always obtain a free stream index number since |
483 | * the worst case scenario is that there are VIDEO_NUM_DEVICES - 1 slots in | |
484 | * use of the video_device array. | |
485 | * | |
486 | * Returns a free index number. | |
27a5e6d3 | 487 | */ |
7ae0cd9b | 488 | static int get_index(struct video_device *vdev) |
27a5e6d3 | 489 | { |
775a05dd HV |
490 | /* This can be static since this function is called with the global |
491 | videodev_lock held. */ | |
492 | static DECLARE_BITMAP(used, VIDEO_NUM_DEVICES); | |
27a5e6d3 HV |
493 | int i; |
494 | ||
7ae0cd9b | 495 | /* Some drivers do not set the parent. In that case always return 0. */ |
806e5b7c | 496 | if (vdev->parent == NULL) |
7ae0cd9b | 497 | return 0; |
775a05dd HV |
498 | |
499 | bitmap_zero(used, VIDEO_NUM_DEVICES); | |
806e5b7c | 500 | |
27a5e6d3 HV |
501 | for (i = 0; i < VIDEO_NUM_DEVICES; i++) { |
502 | if (video_device[i] != NULL && | |
5e85e732 | 503 | video_device[i]->parent == vdev->parent) { |
775a05dd | 504 | set_bit(video_device[i]->index, used); |
27a5e6d3 HV |
505 | } |
506 | } | |
507 | ||
7ae0cd9b | 508 | return find_first_zero_bit(used, VIDEO_NUM_DEVICES); |
27a5e6d3 HV |
509 | } |
510 | ||
27a5e6d3 | 511 | /** |
2096a5dc | 512 | * __video_register_device - register video4linux devices |
dc93a70c | 513 | * @vdev: video device structure we want to register |
27a5e6d3 | 514 | * @type: type of device to register |
22e22125 | 515 | * @nr: which device node number (0 == /dev/video0, 1 == /dev/video1, ... |
27a5e6d3 | 516 | * -1 == first free) |
6b5270d2 HV |
517 | * @warn_if_nr_in_use: warn if the desired device node number |
518 | * was already in use and another number was chosen instead. | |
2096a5dc | 519 | * @owner: module that owns the video device node |
27a5e6d3 | 520 | * |
22e22125 HV |
521 | * The registration code assigns minor numbers and device node numbers |
522 | * based on the requested type and registers the new device node with | |
523 | * the kernel. | |
46b63377 HV |
524 | * |
525 | * This function assumes that struct video_device was zeroed when it | |
526 | * was allocated and does not contain any stale date. | |
527 | * | |
22e22125 HV |
528 | * An error is returned if no free minor or device node number could be |
529 | * found, or if the registration of the device node failed. | |
27a5e6d3 HV |
530 | * |
531 | * Zero is returned on success. | |
532 | * | |
533 | * Valid types are | |
534 | * | |
535 | * %VFL_TYPE_GRABBER - A frame grabber | |
536 | * | |
27a5e6d3 HV |
537 | * %VFL_TYPE_VBI - Vertical blank data (undecoded) |
538 | * | |
539 | * %VFL_TYPE_RADIO - A radio card | |
2096a5dc LP |
540 | * |
541 | * %VFL_TYPE_SUBDEV - A subdevice | |
27a5e6d3 | 542 | */ |
2096a5dc LP |
543 | int __video_register_device(struct video_device *vdev, int type, int nr, |
544 | int warn_if_nr_in_use, struct module *owner) | |
27a5e6d3 HV |
545 | { |
546 | int i = 0; | |
27a5e6d3 | 547 | int ret; |
dd89601d HV |
548 | int minor_offset = 0; |
549 | int minor_cnt = VIDEO_NUM_DEVICES; | |
550 | const char *name_base; | |
27a5e6d3 | 551 | |
dc93a70c HV |
552 | /* A minor value of -1 marks this video device as never |
553 | having been registered */ | |
428c8d19 | 554 | vdev->minor = -1; |
ee7aa9f8 | 555 | |
dc93a70c | 556 | /* the release callback MUST be present */ |
1fc2b5f7 | 557 | if (WARN_ON(!vdev->release)) |
f3b9f50e HK |
558 | return -EINVAL; |
559 | ||
1babcb46 SA |
560 | /* v4l2_fh support */ |
561 | spin_lock_init(&vdev->fh_lock); | |
562 | INIT_LIST_HEAD(&vdev->fh_list); | |
563 | ||
dc93a70c | 564 | /* Part 1: check device type */ |
27a5e6d3 HV |
565 | switch (type) { |
566 | case VFL_TYPE_GRABBER: | |
27a5e6d3 HV |
567 | name_base = "video"; |
568 | break; | |
27a5e6d3 | 569 | case VFL_TYPE_VBI: |
27a5e6d3 HV |
570 | name_base = "vbi"; |
571 | break; | |
572 | case VFL_TYPE_RADIO: | |
27a5e6d3 HV |
573 | name_base = "radio"; |
574 | break; | |
2096a5dc LP |
575 | case VFL_TYPE_SUBDEV: |
576 | name_base = "v4l-subdev"; | |
577 | break; | |
27a5e6d3 HV |
578 | default: |
579 | printk(KERN_ERR "%s called with unknown type: %d\n", | |
580 | __func__, type); | |
46f2c21c | 581 | return -EINVAL; |
27a5e6d3 HV |
582 | } |
583 | ||
dc93a70c HV |
584 | vdev->vfl_type = type; |
585 | vdev->cdev = NULL; | |
11bbc1ca HV |
586 | if (vdev->v4l2_dev) { |
587 | if (vdev->v4l2_dev->dev) | |
588 | vdev->parent = vdev->v4l2_dev->dev; | |
589 | if (vdev->ctrl_handler == NULL) | |
590 | vdev->ctrl_handler = vdev->v4l2_dev->ctrl_handler; | |
b1a873a3 HV |
591 | /* If the prio state pointer is NULL, then use the v4l2_device |
592 | prio state. */ | |
593 | if (vdev->prio == NULL) | |
0f62fd6a | 594 | vdev->prio = &vdev->v4l2_dev->prio; |
11bbc1ca | 595 | } |
dd89601d | 596 | |
22e22125 | 597 | /* Part 2: find a free minor, device node number and device index. */ |
dd89601d HV |
598 | #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES |
599 | /* Keep the ranges for the first four types for historical | |
600 | * reasons. | |
601 | * Newer devices (not yet in place) should use the range | |
602 | * of 128-191 and just pick the first free minor there | |
603 | * (new style). */ | |
604 | switch (type) { | |
605 | case VFL_TYPE_GRABBER: | |
606 | minor_offset = 0; | |
607 | minor_cnt = 64; | |
608 | break; | |
609 | case VFL_TYPE_RADIO: | |
610 | minor_offset = 64; | |
611 | minor_cnt = 64; | |
612 | break; | |
dd89601d HV |
613 | case VFL_TYPE_VBI: |
614 | minor_offset = 224; | |
615 | minor_cnt = 32; | |
616 | break; | |
617 | default: | |
618 | minor_offset = 128; | |
619 | minor_cnt = 64; | |
620 | break; | |
621 | } | |
622 | #endif | |
623 | ||
22e22125 | 624 | /* Pick a device node number */ |
27a5e6d3 | 625 | mutex_lock(&videodev_lock); |
5062cb70 | 626 | nr = devnode_find(vdev, nr == -1 ? 0 : nr, minor_cnt); |
dd89601d | 627 | if (nr == minor_cnt) |
5062cb70 | 628 | nr = devnode_find(vdev, 0, minor_cnt); |
dd89601d | 629 | if (nr == minor_cnt) { |
22e22125 | 630 | printk(KERN_ERR "could not get a free device node number\n"); |
dd89601d HV |
631 | mutex_unlock(&videodev_lock); |
632 | return -ENFILE; | |
27a5e6d3 | 633 | } |
dd89601d | 634 | #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES |
22e22125 | 635 | /* 1-on-1 mapping of device node number to minor number */ |
dd89601d HV |
636 | i = nr; |
637 | #else | |
22e22125 HV |
638 | /* The device node number and minor numbers are independent, so |
639 | we just find the first free minor number. */ | |
dd89601d HV |
640 | for (i = 0; i < VIDEO_NUM_DEVICES; i++) |
641 | if (video_device[i] == NULL) | |
642 | break; | |
643 | if (i == VIDEO_NUM_DEVICES) { | |
644 | mutex_unlock(&videodev_lock); | |
645 | printk(KERN_ERR "could not get a free minor\n"); | |
646 | return -ENFILE; | |
647 | } | |
648 | #endif | |
dc93a70c HV |
649 | vdev->minor = i + minor_offset; |
650 | vdev->num = nr; | |
5062cb70 HV |
651 | devnode_set(vdev); |
652 | ||
dc93a70c HV |
653 | /* Should not happen since we thought this minor was free */ |
654 | WARN_ON(video_device[vdev->minor] != NULL); | |
7ae0cd9b | 655 | vdev->index = get_index(vdev); |
27a5e6d3 HV |
656 | mutex_unlock(&videodev_lock); |
657 | ||
dc93a70c HV |
658 | /* Part 3: Initialize the character device */ |
659 | vdev->cdev = cdev_alloc(); | |
660 | if (vdev->cdev == NULL) { | |
661 | ret = -ENOMEM; | |
662 | goto cleanup; | |
663 | } | |
86a5ef7d | 664 | vdev->cdev->ops = &v4l2_fops; |
2096a5dc | 665 | vdev->cdev->owner = owner; |
dc93a70c | 666 | ret = cdev_add(vdev->cdev, MKDEV(VIDEO_MAJOR, vdev->minor), 1); |
7f8ecfab HV |
667 | if (ret < 0) { |
668 | printk(KERN_ERR "%s: cdev_add failed\n", __func__); | |
dc93a70c HV |
669 | kfree(vdev->cdev); |
670 | vdev->cdev = NULL; | |
671 | goto cleanup; | |
7f8ecfab | 672 | } |
dc93a70c HV |
673 | |
674 | /* Part 4: register the device with sysfs */ | |
dc93a70c HV |
675 | vdev->dev.class = &video_class; |
676 | vdev->dev.devt = MKDEV(VIDEO_MAJOR, vdev->minor); | |
677 | if (vdev->parent) | |
678 | vdev->dev.parent = vdev->parent; | |
22e22125 | 679 | dev_set_name(&vdev->dev, "%s%d", name_base, vdev->num); |
dc93a70c | 680 | ret = device_register(&vdev->dev); |
27a5e6d3 HV |
681 | if (ret < 0) { |
682 | printk(KERN_ERR "%s: device_register failed\n", __func__); | |
dc93a70c | 683 | goto cleanup; |
27a5e6d3 | 684 | } |
dc93a70c HV |
685 | /* Register the release callback that will be called when the last |
686 | reference to the device goes away. */ | |
687 | vdev->dev.release = v4l2_device_release; | |
27a5e6d3 | 688 | |
6b5270d2 | 689 | if (nr != -1 && nr != vdev->num && warn_if_nr_in_use) |
eac8ea53 LP |
690 | printk(KERN_WARNING "%s: requested %s%d, got %s\n", __func__, |
691 | name_base, nr, video_device_node_name(vdev)); | |
bedf8bcf HV |
692 | |
693 | /* Increase v4l2_device refcount */ | |
694 | if (vdev->v4l2_dev) | |
695 | v4l2_device_get(vdev->v4l2_dev); | |
696 | ||
2c0ab67b LP |
697 | #if defined(CONFIG_MEDIA_CONTROLLER) |
698 | /* Part 5: Register the entity. */ | |
c4f0b78a LP |
699 | if (vdev->v4l2_dev && vdev->v4l2_dev->mdev && |
700 | vdev->vfl_type != VFL_TYPE_SUBDEV) { | |
2c0ab67b LP |
701 | vdev->entity.type = MEDIA_ENT_T_DEVNODE_V4L; |
702 | vdev->entity.name = vdev->name; | |
fa5034c6 CL |
703 | vdev->entity.info.v4l.major = VIDEO_MAJOR; |
704 | vdev->entity.info.v4l.minor = vdev->minor; | |
2c0ab67b LP |
705 | ret = media_device_register_entity(vdev->v4l2_dev->mdev, |
706 | &vdev->entity); | |
707 | if (ret < 0) | |
708 | printk(KERN_WARNING | |
709 | "%s: media_device_register_entity failed\n", | |
710 | __func__); | |
711 | } | |
712 | #endif | |
713 | /* Part 6: Activate this minor. The char device can now be used. */ | |
957b4aa9 | 714 | set_bit(V4L2_FL_REGISTERED, &vdev->flags); |
dc93a70c HV |
715 | mutex_lock(&videodev_lock); |
716 | video_device[vdev->minor] = vdev; | |
717 | mutex_unlock(&videodev_lock); | |
2c0ab67b | 718 | |
dc93a70c | 719 | return 0; |
7f8ecfab | 720 | |
dc93a70c | 721 | cleanup: |
27a5e6d3 | 722 | mutex_lock(&videodev_lock); |
dc93a70c HV |
723 | if (vdev->cdev) |
724 | cdev_del(vdev->cdev); | |
5062cb70 | 725 | devnode_clear(vdev); |
27a5e6d3 | 726 | mutex_unlock(&videodev_lock); |
dc93a70c HV |
727 | /* Mark this video device as never having been registered. */ |
728 | vdev->minor = -1; | |
27a5e6d3 HV |
729 | return ret; |
730 | } | |
2096a5dc | 731 | EXPORT_SYMBOL(__video_register_device); |
6b5270d2 | 732 | |
27a5e6d3 HV |
733 | /** |
734 | * video_unregister_device - unregister a video4linux device | |
dc93a70c | 735 | * @vdev: the device to unregister |
27a5e6d3 | 736 | * |
dc93a70c HV |
737 | * This unregisters the passed device. Future open calls will |
738 | * be met with errors. | |
27a5e6d3 | 739 | */ |
dc93a70c | 740 | void video_unregister_device(struct video_device *vdev) |
27a5e6d3 | 741 | { |
dc93a70c | 742 | /* Check if vdev was ever registered at all */ |
957b4aa9 | 743 | if (!vdev || !video_is_registered(vdev)) |
dc93a70c HV |
744 | return; |
745 | ||
ca9afe6f HV |
746 | mutex_lock(&videodev_lock); |
747 | /* This must be in a critical section to prevent a race with v4l2_open. | |
748 | * Once this bit has been cleared video_get may never be called again. | |
749 | */ | |
957b4aa9 | 750 | clear_bit(V4L2_FL_REGISTERED, &vdev->flags); |
ca9afe6f | 751 | mutex_unlock(&videodev_lock); |
dc93a70c | 752 | device_unregister(&vdev->dev); |
27a5e6d3 HV |
753 | } |
754 | EXPORT_SYMBOL(video_unregister_device); | |
755 | ||
27a5e6d3 HV |
756 | /* |
757 | * Initialise video for linux | |
758 | */ | |
27a5e6d3 HV |
759 | static int __init videodev_init(void) |
760 | { | |
7f8ecfab | 761 | dev_t dev = MKDEV(VIDEO_MAJOR, 0); |
27a5e6d3 HV |
762 | int ret; |
763 | ||
764 | printk(KERN_INFO "Linux video capture interface: v2.00\n"); | |
7f8ecfab HV |
765 | ret = register_chrdev_region(dev, VIDEO_NUM_DEVICES, VIDEO_NAME); |
766 | if (ret < 0) { | |
767 | printk(KERN_WARNING "videodev: unable to get major %d\n", | |
768 | VIDEO_MAJOR); | |
769 | return ret; | |
27a5e6d3 HV |
770 | } |
771 | ||
772 | ret = class_register(&video_class); | |
773 | if (ret < 0) { | |
7f8ecfab | 774 | unregister_chrdev_region(dev, VIDEO_NUM_DEVICES); |
27a5e6d3 HV |
775 | printk(KERN_WARNING "video_dev: class_register failed\n"); |
776 | return -EIO; | |
777 | } | |
778 | ||
779 | return 0; | |
780 | } | |
781 | ||
782 | static void __exit videodev_exit(void) | |
783 | { | |
7f8ecfab HV |
784 | dev_t dev = MKDEV(VIDEO_MAJOR, 0); |
785 | ||
27a5e6d3 | 786 | class_unregister(&video_class); |
7f8ecfab | 787 | unregister_chrdev_region(dev, VIDEO_NUM_DEVICES); |
27a5e6d3 HV |
788 | } |
789 | ||
ee981c6f | 790 | subsys_initcall(videodev_init); |
27a5e6d3 HV |
791 | module_exit(videodev_exit) |
792 | ||
793 | MODULE_AUTHOR("Alan Cox, Mauro Carvalho Chehab <mchehab@infradead.org>"); | |
794 | MODULE_DESCRIPTION("Device registrar for Video4Linux drivers v2"); | |
795 | MODULE_LICENSE("GPL"); | |
cbb72b0f | 796 | MODULE_ALIAS_CHARDEV_MAJOR(VIDEO_MAJOR); |
27a5e6d3 HV |
797 | |
798 | ||
799 | /* | |
800 | * Local variables: | |
801 | * c-basic-offset: 8 | |
802 | * End: | |
803 | */ |