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> | |
28 | #include <linux/smp_lock.h> | |
29 | #include <asm/uaccess.h> | |
30 | #include <asm/system.h> | |
31 | ||
32 | #include <media/v4l2-common.h> | |
9bea3514 | 33 | #include <media/v4l2-device.h> |
bec43661 | 34 | #include <media/v4l2-ioctl.h> |
27a5e6d3 HV |
35 | |
36 | #define VIDEO_NUM_DEVICES 256 | |
37 | #define VIDEO_NAME "video4linux" | |
38 | ||
39 | /* | |
40 | * sysfs stuff | |
41 | */ | |
42 | ||
43 | static ssize_t show_index(struct device *cd, | |
44 | struct device_attribute *attr, char *buf) | |
45 | { | |
dc93a70c | 46 | struct video_device *vdev = to_video_device(cd); |
bfa8a273 | 47 | |
dc93a70c | 48 | return sprintf(buf, "%i\n", vdev->index); |
27a5e6d3 HV |
49 | } |
50 | ||
51 | static ssize_t show_name(struct device *cd, | |
52 | struct device_attribute *attr, char *buf) | |
53 | { | |
dc93a70c | 54 | struct video_device *vdev = to_video_device(cd); |
bfa8a273 | 55 | |
dc93a70c | 56 | return sprintf(buf, "%.*s\n", (int)sizeof(vdev->name), vdev->name); |
27a5e6d3 HV |
57 | } |
58 | ||
59 | static struct device_attribute video_device_attrs[] = { | |
60 | __ATTR(name, S_IRUGO, show_name, NULL), | |
61 | __ATTR(index, S_IRUGO, show_index, NULL), | |
62 | __ATTR_NULL | |
63 | }; | |
64 | ||
7f8ecfab HV |
65 | /* |
66 | * Active devices | |
67 | */ | |
68 | static struct video_device *video_device[VIDEO_NUM_DEVICES]; | |
69 | static DEFINE_MUTEX(videodev_lock); | |
dd89601d | 70 | static DECLARE_BITMAP(video_nums[VFL_TYPE_MAX], VIDEO_NUM_DEVICES); |
7f8ecfab | 71 | |
27a5e6d3 HV |
72 | struct video_device *video_device_alloc(void) |
73 | { | |
bfa8a273 | 74 | return kzalloc(sizeof(struct video_device), GFP_KERNEL); |
27a5e6d3 HV |
75 | } |
76 | EXPORT_SYMBOL(video_device_alloc); | |
77 | ||
dc93a70c | 78 | void video_device_release(struct video_device *vdev) |
27a5e6d3 | 79 | { |
dc93a70c | 80 | kfree(vdev); |
27a5e6d3 HV |
81 | } |
82 | EXPORT_SYMBOL(video_device_release); | |
83 | ||
dc93a70c | 84 | void video_device_release_empty(struct video_device *vdev) |
f9e86b5e HV |
85 | { |
86 | /* Do nothing */ | |
87 | /* Only valid when the video_device struct is a static. */ | |
88 | } | |
89 | EXPORT_SYMBOL(video_device_release_empty); | |
90 | ||
dc93a70c | 91 | static inline void video_get(struct video_device *vdev) |
7f8ecfab | 92 | { |
dc93a70c HV |
93 | get_device(&vdev->dev); |
94 | } | |
95 | ||
96 | static inline void video_put(struct video_device *vdev) | |
97 | { | |
98 | put_device(&vdev->dev); | |
99 | } | |
100 | ||
101 | /* Called when the last user of the video device exits. */ | |
102 | static void v4l2_device_release(struct device *cd) | |
103 | { | |
104 | struct video_device *vdev = to_video_device(cd); | |
7f8ecfab HV |
105 | |
106 | mutex_lock(&videodev_lock); | |
dc93a70c | 107 | if (video_device[vdev->minor] != vdev) { |
6ea9a182 | 108 | mutex_unlock(&videodev_lock); |
dc93a70c HV |
109 | /* should not happen */ |
110 | WARN_ON(1); | |
6ea9a182 HV |
111 | return; |
112 | } | |
7f8ecfab HV |
113 | |
114 | /* Free up this device for reuse */ | |
dc93a70c | 115 | video_device[vdev->minor] = NULL; |
7f8ecfab | 116 | |
dc93a70c HV |
117 | /* Delete the cdev on this minor as well */ |
118 | cdev_del(vdev->cdev); | |
119 | /* Just in case some driver tries to access this from | |
120 | the release() callback. */ | |
121 | vdev->cdev = NULL; | |
7f8ecfab | 122 | |
dc93a70c HV |
123 | /* Mark minor as free */ |
124 | clear_bit(vdev->num, video_nums[vdev->vfl_type]); | |
7f8ecfab | 125 | |
dc93a70c | 126 | mutex_unlock(&videodev_lock); |
27a5e6d3 | 127 | |
dc93a70c HV |
128 | /* Release video_device and perform other |
129 | cleanups as needed. */ | |
130 | vdev->release(vdev); | |
27a5e6d3 HV |
131 | } |
132 | ||
133 | static struct class video_class = { | |
134 | .name = VIDEO_NAME, | |
135 | .dev_attrs = video_device_attrs, | |
27a5e6d3 HV |
136 | }; |
137 | ||
27a5e6d3 HV |
138 | struct video_device *video_devdata(struct file *file) |
139 | { | |
140 | return video_device[iminor(file->f_path.dentry->d_inode)]; | |
141 | } | |
142 | EXPORT_SYMBOL(video_devdata); | |
143 | ||
dc93a70c HV |
144 | static ssize_t v4l2_read(struct file *filp, char __user *buf, |
145 | size_t sz, loff_t *off) | |
146 | { | |
147 | struct video_device *vdev = video_devdata(filp); | |
148 | ||
149 | if (!vdev->fops->read) | |
150 | return -EINVAL; | |
151 | if (video_is_unregistered(vdev)) | |
152 | return -EIO; | |
153 | return vdev->fops->read(filp, buf, sz, off); | |
154 | } | |
155 | ||
156 | static ssize_t v4l2_write(struct file *filp, const char __user *buf, | |
157 | size_t sz, loff_t *off) | |
158 | { | |
159 | struct video_device *vdev = video_devdata(filp); | |
160 | ||
161 | if (!vdev->fops->write) | |
162 | return -EINVAL; | |
163 | if (video_is_unregistered(vdev)) | |
164 | return -EIO; | |
165 | return vdev->fops->write(filp, buf, sz, off); | |
166 | } | |
167 | ||
168 | static unsigned int v4l2_poll(struct file *filp, struct poll_table_struct *poll) | |
169 | { | |
170 | struct video_device *vdev = video_devdata(filp); | |
171 | ||
172 | if (!vdev->fops->poll || video_is_unregistered(vdev)) | |
173 | return DEFAULT_POLLMASK; | |
174 | return vdev->fops->poll(filp, poll); | |
175 | } | |
176 | ||
177 | static int v4l2_ioctl(struct inode *inode, struct file *filp, | |
178 | unsigned int cmd, unsigned long arg) | |
179 | { | |
180 | struct video_device *vdev = video_devdata(filp); | |
181 | ||
182 | if (!vdev->fops->ioctl) | |
183 | return -ENOTTY; | |
184 | /* Allow ioctl to continue even if the device was unregistered. | |
185 | Things like dequeueing buffers might still be useful. */ | |
bec43661 | 186 | return vdev->fops->ioctl(filp, cmd, arg); |
dc93a70c HV |
187 | } |
188 | ||
189 | static long v4l2_unlocked_ioctl(struct file *filp, | |
190 | unsigned int cmd, unsigned long arg) | |
191 | { | |
192 | struct video_device *vdev = video_devdata(filp); | |
193 | ||
194 | if (!vdev->fops->unlocked_ioctl) | |
195 | return -ENOTTY; | |
196 | /* Allow ioctl to continue even if the device was unregistered. | |
197 | Things like dequeueing buffers might still be useful. */ | |
198 | return vdev->fops->unlocked_ioctl(filp, cmd, arg); | |
199 | } | |
200 | ||
dc93a70c HV |
201 | static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm) |
202 | { | |
203 | struct video_device *vdev = video_devdata(filp); | |
204 | ||
205 | if (!vdev->fops->mmap || | |
206 | video_is_unregistered(vdev)) | |
207 | return -ENODEV; | |
208 | return vdev->fops->mmap(filp, vm); | |
209 | } | |
210 | ||
211 | /* Override for the open function */ | |
212 | static int v4l2_open(struct inode *inode, struct file *filp) | |
213 | { | |
214 | struct video_device *vdev; | |
215 | int ret; | |
216 | ||
217 | /* Check if the video device is available */ | |
218 | mutex_lock(&videodev_lock); | |
219 | vdev = video_devdata(filp); | |
220 | /* return ENODEV if the video device has been removed | |
221 | already or if it is not registered anymore. */ | |
222 | if (vdev == NULL || video_is_unregistered(vdev)) { | |
223 | mutex_unlock(&videodev_lock); | |
224 | return -ENODEV; | |
225 | } | |
226 | /* and increase the device refcount */ | |
227 | video_get(vdev); | |
228 | mutex_unlock(&videodev_lock); | |
bec43661 | 229 | ret = vdev->fops->open(filp); |
dc93a70c HV |
230 | /* decrease the refcount in case of an error */ |
231 | if (ret) | |
232 | video_put(vdev); | |
233 | return ret; | |
234 | } | |
235 | ||
236 | /* Override for the release function */ | |
237 | static int v4l2_release(struct inode *inode, struct file *filp) | |
238 | { | |
239 | struct video_device *vdev = video_devdata(filp); | |
bec43661 | 240 | int ret = vdev->fops->release(filp); |
dc93a70c HV |
241 | |
242 | /* decrease the refcount unconditionally since the release() | |
243 | return value is ignored. */ | |
244 | video_put(vdev); | |
245 | return ret; | |
246 | } | |
247 | ||
248 | static const struct file_operations v4l2_unlocked_fops = { | |
249 | .owner = THIS_MODULE, | |
250 | .read = v4l2_read, | |
251 | .write = v4l2_write, | |
252 | .open = v4l2_open, | |
253 | .mmap = v4l2_mmap, | |
254 | .unlocked_ioctl = v4l2_unlocked_ioctl, | |
255 | #ifdef CONFIG_COMPAT | |
9bb7cde7 | 256 | .compat_ioctl = v4l2_compat_ioctl32, |
dc93a70c HV |
257 | #endif |
258 | .release = v4l2_release, | |
259 | .poll = v4l2_poll, | |
260 | .llseek = no_llseek, | |
261 | }; | |
262 | ||
263 | static const struct file_operations v4l2_fops = { | |
264 | .owner = THIS_MODULE, | |
265 | .read = v4l2_read, | |
266 | .write = v4l2_write, | |
267 | .open = v4l2_open, | |
268 | .mmap = v4l2_mmap, | |
269 | .ioctl = v4l2_ioctl, | |
270 | #ifdef CONFIG_COMPAT | |
9bb7cde7 | 271 | .compat_ioctl = v4l2_compat_ioctl32, |
dc93a70c HV |
272 | #endif |
273 | .release = v4l2_release, | |
274 | .poll = v4l2_poll, | |
275 | .llseek = no_llseek, | |
276 | }; | |
277 | ||
27a5e6d3 HV |
278 | /** |
279 | * get_index - assign stream number based on parent device | |
dc93a70c HV |
280 | * @vdev: video_device to assign index number to, vdev->parent should be assigned |
281 | * @num: -1 if auto assign, requested number otherwise | |
27a5e6d3 | 282 | * |
dc93a70c HV |
283 | * Note that when this is called the new device has not yet been registered |
284 | * in the video_device array. | |
27a5e6d3 | 285 | * |
dc93a70c | 286 | * Returns -ENFILE if num is already in use, a free index number if |
27a5e6d3 HV |
287 | * successful. |
288 | */ | |
289 | static int get_index(struct video_device *vdev, int num) | |
290 | { | |
291 | u32 used = 0; | |
292 | const int max_index = sizeof(used) * 8 - 1; | |
293 | int i; | |
294 | ||
295 | /* Currently a single v4l driver instance cannot create more than | |
296 | 32 devices. | |
297 | Increase to u64 or an array of u32 if more are needed. */ | |
298 | if (num > max_index) { | |
299 | printk(KERN_ERR "videodev: %s num is too large\n", __func__); | |
300 | return -EINVAL; | |
301 | } | |
302 | ||
806e5b7c HV |
303 | /* Some drivers do not set the parent. In that case always return 0. */ |
304 | if (vdev->parent == NULL) | |
305 | return 0; | |
306 | ||
27a5e6d3 HV |
307 | for (i = 0; i < VIDEO_NUM_DEVICES; i++) { |
308 | if (video_device[i] != NULL && | |
5e85e732 | 309 | video_device[i]->parent == vdev->parent) { |
27a5e6d3 HV |
310 | used |= 1 << video_device[i]->index; |
311 | } | |
312 | } | |
313 | ||
314 | if (num >= 0) { | |
315 | if (used & (1 << num)) | |
316 | return -ENFILE; | |
317 | return num; | |
318 | } | |
319 | ||
320 | i = ffz(used); | |
321 | return i > max_index ? -ENFILE : i; | |
322 | } | |
323 | ||
dc93a70c | 324 | int video_register_device(struct video_device *vdev, int type, int nr) |
27a5e6d3 | 325 | { |
dc93a70c | 326 | return video_register_device_index(vdev, type, nr, -1); |
27a5e6d3 HV |
327 | } |
328 | EXPORT_SYMBOL(video_register_device); | |
329 | ||
330 | /** | |
edc9189c | 331 | * video_register_device_index - register video4linux devices |
dc93a70c | 332 | * @vdev: video device structure we want to register |
27a5e6d3 HV |
333 | * @type: type of device to register |
334 | * @nr: which device number (0 == /dev/video0, 1 == /dev/video1, ... | |
335 | * -1 == first free) | |
edc9189c RD |
336 | * @index: stream number based on parent device; |
337 | * -1 if auto assign, requested number otherwise | |
27a5e6d3 HV |
338 | * |
339 | * The registration code assigns minor numbers based on the type | |
340 | * requested. -ENFILE is returned in all the device slots for this | |
341 | * category are full. If not then the minor field is set and the | |
342 | * driver initialize function is called (if non %NULL). | |
343 | * | |
344 | * Zero is returned on success. | |
345 | * | |
346 | * Valid types are | |
347 | * | |
348 | * %VFL_TYPE_GRABBER - A frame grabber | |
349 | * | |
350 | * %VFL_TYPE_VTX - A teletext device | |
351 | * | |
352 | * %VFL_TYPE_VBI - Vertical blank data (undecoded) | |
353 | * | |
354 | * %VFL_TYPE_RADIO - A radio card | |
355 | */ | |
dc93a70c | 356 | int video_register_device_index(struct video_device *vdev, int type, int nr, |
27a5e6d3 HV |
357 | int index) |
358 | { | |
359 | int i = 0; | |
27a5e6d3 | 360 | int ret; |
dd89601d HV |
361 | int minor_offset = 0; |
362 | int minor_cnt = VIDEO_NUM_DEVICES; | |
363 | const char *name_base; | |
dc93a70c | 364 | void *priv = video_get_drvdata(vdev); |
27a5e6d3 | 365 | |
dc93a70c HV |
366 | /* A minor value of -1 marks this video device as never |
367 | having been registered */ | |
368 | if (vdev) | |
369 | vdev->minor = -1; | |
ee7aa9f8 | 370 | |
dc93a70c HV |
371 | /* the release callback MUST be present */ |
372 | WARN_ON(!vdev || !vdev->release); | |
373 | if (!vdev || !vdev->release) | |
f3b9f50e HK |
374 | return -EINVAL; |
375 | ||
dc93a70c | 376 | /* Part 1: check device type */ |
27a5e6d3 HV |
377 | switch (type) { |
378 | case VFL_TYPE_GRABBER: | |
27a5e6d3 HV |
379 | name_base = "video"; |
380 | break; | |
381 | case VFL_TYPE_VTX: | |
27a5e6d3 HV |
382 | name_base = "vtx"; |
383 | break; | |
384 | case VFL_TYPE_VBI: | |
27a5e6d3 HV |
385 | name_base = "vbi"; |
386 | break; | |
387 | case VFL_TYPE_RADIO: | |
27a5e6d3 HV |
388 | name_base = "radio"; |
389 | break; | |
390 | default: | |
391 | printk(KERN_ERR "%s called with unknown type: %d\n", | |
392 | __func__, type); | |
46f2c21c | 393 | return -EINVAL; |
27a5e6d3 HV |
394 | } |
395 | ||
dc93a70c HV |
396 | vdev->vfl_type = type; |
397 | vdev->cdev = NULL; | |
9bea3514 HV |
398 | if (vdev->v4l2_dev) |
399 | vdev->parent = vdev->v4l2_dev->dev; | |
dd89601d | 400 | |
dc93a70c | 401 | /* Part 2: find a free minor, kernel number and device index. */ |
dd89601d HV |
402 | #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES |
403 | /* Keep the ranges for the first four types for historical | |
404 | * reasons. | |
405 | * Newer devices (not yet in place) should use the range | |
406 | * of 128-191 and just pick the first free minor there | |
407 | * (new style). */ | |
408 | switch (type) { | |
409 | case VFL_TYPE_GRABBER: | |
410 | minor_offset = 0; | |
411 | minor_cnt = 64; | |
412 | break; | |
413 | case VFL_TYPE_RADIO: | |
414 | minor_offset = 64; | |
415 | minor_cnt = 64; | |
416 | break; | |
417 | case VFL_TYPE_VTX: | |
418 | minor_offset = 192; | |
419 | minor_cnt = 32; | |
420 | break; | |
421 | case VFL_TYPE_VBI: | |
422 | minor_offset = 224; | |
423 | minor_cnt = 32; | |
424 | break; | |
425 | default: | |
426 | minor_offset = 128; | |
427 | minor_cnt = 64; | |
428 | break; | |
429 | } | |
430 | #endif | |
431 | ||
dc93a70c | 432 | /* Pick a minor number */ |
27a5e6d3 | 433 | mutex_lock(&videodev_lock); |
dd89601d HV |
434 | nr = find_next_zero_bit(video_nums[type], minor_cnt, nr == -1 ? 0 : nr); |
435 | if (nr == minor_cnt) | |
436 | nr = find_first_zero_bit(video_nums[type], minor_cnt); | |
437 | if (nr == minor_cnt) { | |
438 | printk(KERN_ERR "could not get a free kernel number\n"); | |
439 | mutex_unlock(&videodev_lock); | |
440 | return -ENFILE; | |
27a5e6d3 | 441 | } |
dd89601d HV |
442 | #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES |
443 | /* 1-on-1 mapping of kernel number to minor number */ | |
444 | i = nr; | |
445 | #else | |
446 | /* The kernel number and minor numbers are independent */ | |
447 | for (i = 0; i < VIDEO_NUM_DEVICES; i++) | |
448 | if (video_device[i] == NULL) | |
449 | break; | |
450 | if (i == VIDEO_NUM_DEVICES) { | |
451 | mutex_unlock(&videodev_lock); | |
452 | printk(KERN_ERR "could not get a free minor\n"); | |
453 | return -ENFILE; | |
454 | } | |
455 | #endif | |
dc93a70c HV |
456 | vdev->minor = i + minor_offset; |
457 | vdev->num = nr; | |
dd89601d | 458 | set_bit(nr, video_nums[type]); |
dc93a70c HV |
459 | /* Should not happen since we thought this minor was free */ |
460 | WARN_ON(video_device[vdev->minor] != NULL); | |
461 | ret = vdev->index = get_index(vdev, index); | |
27a5e6d3 HV |
462 | mutex_unlock(&videodev_lock); |
463 | ||
464 | if (ret < 0) { | |
465 | printk(KERN_ERR "%s: get_index failed\n", __func__); | |
dc93a70c | 466 | goto cleanup; |
27a5e6d3 HV |
467 | } |
468 | ||
dc93a70c HV |
469 | /* Part 3: Initialize the character device */ |
470 | vdev->cdev = cdev_alloc(); | |
471 | if (vdev->cdev == NULL) { | |
472 | ret = -ENOMEM; | |
473 | goto cleanup; | |
474 | } | |
475 | if (vdev->fops->unlocked_ioctl) | |
476 | vdev->cdev->ops = &v4l2_unlocked_fops; | |
477 | else | |
478 | vdev->cdev->ops = &v4l2_fops; | |
479 | vdev->cdev->owner = vdev->fops->owner; | |
480 | ret = cdev_add(vdev->cdev, MKDEV(VIDEO_MAJOR, vdev->minor), 1); | |
7f8ecfab HV |
481 | if (ret < 0) { |
482 | printk(KERN_ERR "%s: cdev_add failed\n", __func__); | |
dc93a70c HV |
483 | kfree(vdev->cdev); |
484 | vdev->cdev = NULL; | |
485 | goto cleanup; | |
7f8ecfab | 486 | } |
dc93a70c HV |
487 | |
488 | /* Part 4: register the device with sysfs */ | |
489 | memset(&vdev->dev, 0, sizeof(vdev->dev)); | |
9d95af9d HV |
490 | /* The memset above cleared the device's drvdata, so |
491 | put back the copy we made earlier. */ | |
dc93a70c HV |
492 | video_set_drvdata(vdev, priv); |
493 | vdev->dev.class = &video_class; | |
494 | vdev->dev.devt = MKDEV(VIDEO_MAJOR, vdev->minor); | |
495 | if (vdev->parent) | |
496 | vdev->dev.parent = vdev->parent; | |
497 | dev_set_name(&vdev->dev, "%s%d", name_base, nr); | |
498 | ret = device_register(&vdev->dev); | |
27a5e6d3 HV |
499 | if (ret < 0) { |
500 | printk(KERN_ERR "%s: device_register failed\n", __func__); | |
dc93a70c | 501 | goto cleanup; |
27a5e6d3 | 502 | } |
dc93a70c HV |
503 | /* Register the release callback that will be called when the last |
504 | reference to the device goes away. */ | |
505 | vdev->dev.release = v4l2_device_release; | |
27a5e6d3 | 506 | |
dc93a70c HV |
507 | /* Part 5: Activate this minor. The char device can now be used. */ |
508 | mutex_lock(&videodev_lock); | |
509 | video_device[vdev->minor] = vdev; | |
510 | mutex_unlock(&videodev_lock); | |
511 | return 0; | |
7f8ecfab | 512 | |
dc93a70c | 513 | cleanup: |
27a5e6d3 | 514 | mutex_lock(&videodev_lock); |
dc93a70c HV |
515 | if (vdev->cdev) |
516 | cdev_del(vdev->cdev); | |
517 | clear_bit(vdev->num, video_nums[type]); | |
27a5e6d3 | 518 | mutex_unlock(&videodev_lock); |
dc93a70c HV |
519 | /* Mark this video device as never having been registered. */ |
520 | vdev->minor = -1; | |
27a5e6d3 HV |
521 | return ret; |
522 | } | |
523 | EXPORT_SYMBOL(video_register_device_index); | |
524 | ||
525 | /** | |
526 | * video_unregister_device - unregister a video4linux device | |
dc93a70c | 527 | * @vdev: the device to unregister |
27a5e6d3 | 528 | * |
dc93a70c HV |
529 | * This unregisters the passed device. Future open calls will |
530 | * be met with errors. | |
27a5e6d3 | 531 | */ |
dc93a70c | 532 | void video_unregister_device(struct video_device *vdev) |
27a5e6d3 | 533 | { |
dc93a70c HV |
534 | /* Check if vdev was ever registered at all */ |
535 | if (!vdev || vdev->minor < 0) | |
536 | return; | |
537 | ||
538 | mutex_lock(&videodev_lock); | |
539 | set_bit(V4L2_FL_UNREGISTERED, &vdev->flags); | |
540 | mutex_unlock(&videodev_lock); | |
541 | device_unregister(&vdev->dev); | |
27a5e6d3 HV |
542 | } |
543 | EXPORT_SYMBOL(video_unregister_device); | |
544 | ||
27a5e6d3 HV |
545 | /* |
546 | * Initialise video for linux | |
547 | */ | |
27a5e6d3 HV |
548 | static int __init videodev_init(void) |
549 | { | |
7f8ecfab | 550 | dev_t dev = MKDEV(VIDEO_MAJOR, 0); |
27a5e6d3 HV |
551 | int ret; |
552 | ||
553 | printk(KERN_INFO "Linux video capture interface: v2.00\n"); | |
7f8ecfab HV |
554 | ret = register_chrdev_region(dev, VIDEO_NUM_DEVICES, VIDEO_NAME); |
555 | if (ret < 0) { | |
556 | printk(KERN_WARNING "videodev: unable to get major %d\n", | |
557 | VIDEO_MAJOR); | |
558 | return ret; | |
27a5e6d3 HV |
559 | } |
560 | ||
561 | ret = class_register(&video_class); | |
562 | if (ret < 0) { | |
7f8ecfab | 563 | unregister_chrdev_region(dev, VIDEO_NUM_DEVICES); |
27a5e6d3 HV |
564 | printk(KERN_WARNING "video_dev: class_register failed\n"); |
565 | return -EIO; | |
566 | } | |
567 | ||
568 | return 0; | |
569 | } | |
570 | ||
571 | static void __exit videodev_exit(void) | |
572 | { | |
7f8ecfab HV |
573 | dev_t dev = MKDEV(VIDEO_MAJOR, 0); |
574 | ||
27a5e6d3 | 575 | class_unregister(&video_class); |
7f8ecfab | 576 | unregister_chrdev_region(dev, VIDEO_NUM_DEVICES); |
27a5e6d3 HV |
577 | } |
578 | ||
579 | module_init(videodev_init) | |
580 | module_exit(videodev_exit) | |
581 | ||
582 | MODULE_AUTHOR("Alan Cox, Mauro Carvalho Chehab <mchehab@infradead.org>"); | |
583 | MODULE_DESCRIPTION("Device registrar for Video4Linux drivers v2"); | |
584 | MODULE_LICENSE("GPL"); | |
585 | ||
586 | ||
587 | /* | |
588 | * Local variables: | |
589 | * c-basic-offset: 8 | |
590 | * End: | |
591 | */ |