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 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); | |
dd89601d | 69 | static DECLARE_BITMAP(video_nums[VFL_TYPE_MAX], VIDEO_NUM_DEVICES); |
7f8ecfab | 70 | |
27a5e6d3 HV |
71 | struct video_device *video_device_alloc(void) |
72 | { | |
bfa8a273 | 73 | return kzalloc(sizeof(struct video_device), GFP_KERNEL); |
27a5e6d3 HV |
74 | } |
75 | EXPORT_SYMBOL(video_device_alloc); | |
76 | ||
dc93a70c | 77 | void video_device_release(struct video_device *vdev) |
27a5e6d3 | 78 | { |
dc93a70c | 79 | kfree(vdev); |
27a5e6d3 HV |
80 | } |
81 | EXPORT_SYMBOL(video_device_release); | |
82 | ||
dc93a70c | 83 | void video_device_release_empty(struct video_device *vdev) |
f9e86b5e HV |
84 | { |
85 | /* Do nothing */ | |
86 | /* Only valid when the video_device struct is a static. */ | |
87 | } | |
88 | EXPORT_SYMBOL(video_device_release_empty); | |
89 | ||
dc93a70c | 90 | static inline void video_get(struct video_device *vdev) |
7f8ecfab | 91 | { |
dc93a70c HV |
92 | get_device(&vdev->dev); |
93 | } | |
94 | ||
95 | static inline void video_put(struct video_device *vdev) | |
96 | { | |
97 | put_device(&vdev->dev); | |
98 | } | |
99 | ||
100 | /* Called when the last user of the video device exits. */ | |
101 | static void v4l2_device_release(struct device *cd) | |
102 | { | |
103 | struct video_device *vdev = to_video_device(cd); | |
7f8ecfab HV |
104 | |
105 | mutex_lock(&videodev_lock); | |
dc93a70c | 106 | if (video_device[vdev->minor] != vdev) { |
6ea9a182 | 107 | mutex_unlock(&videodev_lock); |
dc93a70c HV |
108 | /* should not happen */ |
109 | WARN_ON(1); | |
6ea9a182 HV |
110 | return; |
111 | } | |
7f8ecfab HV |
112 | |
113 | /* Free up this device for reuse */ | |
dc93a70c | 114 | video_device[vdev->minor] = NULL; |
7f8ecfab | 115 | |
dc93a70c HV |
116 | /* Delete the cdev on this minor as well */ |
117 | cdev_del(vdev->cdev); | |
118 | /* Just in case some driver tries to access this from | |
119 | the release() callback. */ | |
120 | vdev->cdev = NULL; | |
7f8ecfab | 121 | |
dc93a70c HV |
122 | /* Mark minor as free */ |
123 | clear_bit(vdev->num, video_nums[vdev->vfl_type]); | |
7f8ecfab | 124 | |
dc93a70c | 125 | mutex_unlock(&videodev_lock); |
27a5e6d3 | 126 | |
dc93a70c HV |
127 | /* Release video_device and perform other |
128 | cleanups as needed. */ | |
129 | vdev->release(vdev); | |
27a5e6d3 HV |
130 | } |
131 | ||
132 | static struct class video_class = { | |
133 | .name = VIDEO_NAME, | |
134 | .dev_attrs = video_device_attrs, | |
27a5e6d3 HV |
135 | }; |
136 | ||
27a5e6d3 HV |
137 | struct video_device *video_devdata(struct file *file) |
138 | { | |
139 | return video_device[iminor(file->f_path.dentry->d_inode)]; | |
140 | } | |
141 | EXPORT_SYMBOL(video_devdata); | |
142 | ||
dc93a70c HV |
143 | static ssize_t v4l2_read(struct file *filp, char __user *buf, |
144 | size_t sz, loff_t *off) | |
145 | { | |
146 | struct video_device *vdev = video_devdata(filp); | |
147 | ||
148 | if (!vdev->fops->read) | |
149 | return -EINVAL; | |
150 | if (video_is_unregistered(vdev)) | |
151 | return -EIO; | |
152 | return vdev->fops->read(filp, buf, sz, off); | |
153 | } | |
154 | ||
155 | static ssize_t v4l2_write(struct file *filp, const char __user *buf, | |
156 | size_t sz, loff_t *off) | |
157 | { | |
158 | struct video_device *vdev = video_devdata(filp); | |
159 | ||
160 | if (!vdev->fops->write) | |
161 | return -EINVAL; | |
162 | if (video_is_unregistered(vdev)) | |
163 | return -EIO; | |
164 | return vdev->fops->write(filp, buf, sz, off); | |
165 | } | |
166 | ||
167 | static unsigned int v4l2_poll(struct file *filp, struct poll_table_struct *poll) | |
168 | { | |
169 | struct video_device *vdev = video_devdata(filp); | |
170 | ||
171 | if (!vdev->fops->poll || video_is_unregistered(vdev)) | |
172 | return DEFAULT_POLLMASK; | |
173 | return vdev->fops->poll(filp, poll); | |
174 | } | |
175 | ||
176 | static int v4l2_ioctl(struct inode *inode, struct file *filp, | |
177 | unsigned int cmd, unsigned long arg) | |
178 | { | |
179 | struct video_device *vdev = video_devdata(filp); | |
180 | ||
181 | if (!vdev->fops->ioctl) | |
182 | return -ENOTTY; | |
183 | /* Allow ioctl to continue even if the device was unregistered. | |
184 | Things like dequeueing buffers might still be useful. */ | |
bec43661 | 185 | return vdev->fops->ioctl(filp, cmd, arg); |
dc93a70c HV |
186 | } |
187 | ||
188 | static long v4l2_unlocked_ioctl(struct file *filp, | |
189 | unsigned int cmd, unsigned long arg) | |
190 | { | |
191 | struct video_device *vdev = video_devdata(filp); | |
192 | ||
193 | if (!vdev->fops->unlocked_ioctl) | |
194 | return -ENOTTY; | |
195 | /* Allow ioctl to continue even if the device was unregistered. | |
196 | Things like dequeueing buffers might still be useful. */ | |
197 | return vdev->fops->unlocked_ioctl(filp, cmd, arg); | |
198 | } | |
199 | ||
c01f1a5a DG |
200 | #ifdef CONFIG_MMU |
201 | #define v4l2_get_unmapped_area NULL | |
202 | #else | |
203 | static unsigned long v4l2_get_unmapped_area(struct file *filp, | |
204 | unsigned long addr, unsigned long len, unsigned long pgoff, | |
205 | unsigned long flags) | |
206 | { | |
207 | struct video_device *vdev = video_devdata(filp); | |
208 | ||
209 | if (!vdev->fops->get_unmapped_area) | |
210 | return -ENOSYS; | |
211 | if (video_is_unregistered(vdev)) | |
212 | return -ENODEV; | |
213 | return vdev->fops->get_unmapped_area(filp, addr, len, pgoff, flags); | |
214 | } | |
215 | #endif | |
216 | ||
dc93a70c HV |
217 | static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm) |
218 | { | |
219 | struct video_device *vdev = video_devdata(filp); | |
220 | ||
221 | if (!vdev->fops->mmap || | |
222 | video_is_unregistered(vdev)) | |
223 | return -ENODEV; | |
224 | return vdev->fops->mmap(filp, vm); | |
225 | } | |
226 | ||
227 | /* Override for the open function */ | |
228 | static int v4l2_open(struct inode *inode, struct file *filp) | |
229 | { | |
230 | struct video_device *vdev; | |
65d9ff9c | 231 | int ret = 0; |
dc93a70c HV |
232 | |
233 | /* Check if the video device is available */ | |
234 | mutex_lock(&videodev_lock); | |
235 | vdev = video_devdata(filp); | |
236 | /* return ENODEV if the video device has been removed | |
237 | already or if it is not registered anymore. */ | |
238 | if (vdev == NULL || video_is_unregistered(vdev)) { | |
239 | mutex_unlock(&videodev_lock); | |
240 | return -ENODEV; | |
241 | } | |
242 | /* and increase the device refcount */ | |
243 | video_get(vdev); | |
244 | mutex_unlock(&videodev_lock); | |
65d9ff9c HV |
245 | if (vdev->fops->open) |
246 | ret = vdev->fops->open(filp); | |
247 | ||
dc93a70c HV |
248 | /* decrease the refcount in case of an error */ |
249 | if (ret) | |
250 | video_put(vdev); | |
251 | return ret; | |
252 | } | |
253 | ||
254 | /* Override for the release function */ | |
255 | static int v4l2_release(struct inode *inode, struct file *filp) | |
256 | { | |
257 | struct video_device *vdev = video_devdata(filp); | |
65d9ff9c HV |
258 | int ret = 0; |
259 | ||
260 | if (vdev->fops->release) | |
261 | vdev->fops->release(filp); | |
dc93a70c HV |
262 | |
263 | /* decrease the refcount unconditionally since the release() | |
264 | return value is ignored. */ | |
265 | video_put(vdev); | |
266 | return ret; | |
267 | } | |
268 | ||
269 | static const struct file_operations v4l2_unlocked_fops = { | |
270 | .owner = THIS_MODULE, | |
271 | .read = v4l2_read, | |
272 | .write = v4l2_write, | |
273 | .open = v4l2_open, | |
c01f1a5a | 274 | .get_unmapped_area = v4l2_get_unmapped_area, |
dc93a70c HV |
275 | .mmap = v4l2_mmap, |
276 | .unlocked_ioctl = v4l2_unlocked_ioctl, | |
277 | #ifdef CONFIG_COMPAT | |
9bb7cde7 | 278 | .compat_ioctl = v4l2_compat_ioctl32, |
dc93a70c HV |
279 | #endif |
280 | .release = v4l2_release, | |
281 | .poll = v4l2_poll, | |
282 | .llseek = no_llseek, | |
283 | }; | |
284 | ||
285 | static const struct file_operations v4l2_fops = { | |
286 | .owner = THIS_MODULE, | |
287 | .read = v4l2_read, | |
288 | .write = v4l2_write, | |
289 | .open = v4l2_open, | |
c01f1a5a | 290 | .get_unmapped_area = v4l2_get_unmapped_area, |
dc93a70c HV |
291 | .mmap = v4l2_mmap, |
292 | .ioctl = v4l2_ioctl, | |
293 | #ifdef CONFIG_COMPAT | |
9bb7cde7 | 294 | .compat_ioctl = v4l2_compat_ioctl32, |
dc93a70c HV |
295 | #endif |
296 | .release = v4l2_release, | |
297 | .poll = v4l2_poll, | |
298 | .llseek = no_llseek, | |
299 | }; | |
300 | ||
27a5e6d3 HV |
301 | /** |
302 | * get_index - assign stream number based on parent device | |
dc93a70c HV |
303 | * @vdev: video_device to assign index number to, vdev->parent should be assigned |
304 | * @num: -1 if auto assign, requested number otherwise | |
27a5e6d3 | 305 | * |
dc93a70c HV |
306 | * Note that when this is called the new device has not yet been registered |
307 | * in the video_device array. | |
27a5e6d3 | 308 | * |
dc93a70c | 309 | * Returns -ENFILE if num is already in use, a free index number if |
27a5e6d3 HV |
310 | * successful. |
311 | */ | |
312 | static int get_index(struct video_device *vdev, int num) | |
313 | { | |
775a05dd HV |
314 | /* This can be static since this function is called with the global |
315 | videodev_lock held. */ | |
316 | static DECLARE_BITMAP(used, VIDEO_NUM_DEVICES); | |
27a5e6d3 HV |
317 | int i; |
318 | ||
775a05dd | 319 | if (num >= VIDEO_NUM_DEVICES) { |
27a5e6d3 HV |
320 | printk(KERN_ERR "videodev: %s num is too large\n", __func__); |
321 | return -EINVAL; | |
322 | } | |
323 | ||
775a05dd HV |
324 | /* Some drivers do not set the parent. In that case always return |
325 | num or 0. */ | |
806e5b7c | 326 | if (vdev->parent == NULL) |
775a05dd HV |
327 | return num >= 0 ? num : 0; |
328 | ||
329 | bitmap_zero(used, VIDEO_NUM_DEVICES); | |
806e5b7c | 330 | |
27a5e6d3 HV |
331 | for (i = 0; i < VIDEO_NUM_DEVICES; i++) { |
332 | if (video_device[i] != NULL && | |
5e85e732 | 333 | video_device[i]->parent == vdev->parent) { |
775a05dd | 334 | set_bit(video_device[i]->index, used); |
27a5e6d3 HV |
335 | } |
336 | } | |
337 | ||
338 | if (num >= 0) { | |
775a05dd | 339 | if (test_bit(num, used)) |
27a5e6d3 HV |
340 | return -ENFILE; |
341 | return num; | |
342 | } | |
343 | ||
775a05dd HV |
344 | i = find_first_zero_bit(used, VIDEO_NUM_DEVICES); |
345 | return i == VIDEO_NUM_DEVICES ? -ENFILE : i; | |
27a5e6d3 HV |
346 | } |
347 | ||
dc93a70c | 348 | int video_register_device(struct video_device *vdev, int type, int nr) |
27a5e6d3 | 349 | { |
dc93a70c | 350 | return video_register_device_index(vdev, type, nr, -1); |
27a5e6d3 HV |
351 | } |
352 | EXPORT_SYMBOL(video_register_device); | |
353 | ||
354 | /** | |
edc9189c | 355 | * video_register_device_index - register video4linux devices |
dc93a70c | 356 | * @vdev: video device structure we want to register |
27a5e6d3 HV |
357 | * @type: type of device to register |
358 | * @nr: which device number (0 == /dev/video0, 1 == /dev/video1, ... | |
359 | * -1 == first free) | |
edc9189c RD |
360 | * @index: stream number based on parent device; |
361 | * -1 if auto assign, requested number otherwise | |
27a5e6d3 HV |
362 | * |
363 | * The registration code assigns minor numbers based on the type | |
364 | * requested. -ENFILE is returned in all the device slots for this | |
365 | * category are full. If not then the minor field is set and the | |
366 | * driver initialize function is called (if non %NULL). | |
367 | * | |
368 | * Zero is returned on success. | |
369 | * | |
370 | * Valid types are | |
371 | * | |
372 | * %VFL_TYPE_GRABBER - A frame grabber | |
373 | * | |
374 | * %VFL_TYPE_VTX - A teletext device | |
375 | * | |
376 | * %VFL_TYPE_VBI - Vertical blank data (undecoded) | |
377 | * | |
378 | * %VFL_TYPE_RADIO - A radio card | |
379 | */ | |
dc93a70c | 380 | int video_register_device_index(struct video_device *vdev, int type, int nr, |
27a5e6d3 HV |
381 | int index) |
382 | { | |
383 | int i = 0; | |
27a5e6d3 | 384 | int ret; |
dd89601d HV |
385 | int minor_offset = 0; |
386 | int minor_cnt = VIDEO_NUM_DEVICES; | |
387 | const char *name_base; | |
dc93a70c | 388 | void *priv = video_get_drvdata(vdev); |
27a5e6d3 | 389 | |
dc93a70c HV |
390 | /* A minor value of -1 marks this video device as never |
391 | having been registered */ | |
428c8d19 | 392 | vdev->minor = -1; |
ee7aa9f8 | 393 | |
dc93a70c | 394 | /* the release callback MUST be present */ |
428c8d19 TP |
395 | WARN_ON(!vdev->release); |
396 | if (!vdev->release) | |
f3b9f50e HK |
397 | return -EINVAL; |
398 | ||
dc93a70c | 399 | /* Part 1: check device type */ |
27a5e6d3 HV |
400 | switch (type) { |
401 | case VFL_TYPE_GRABBER: | |
27a5e6d3 HV |
402 | name_base = "video"; |
403 | break; | |
404 | case VFL_TYPE_VTX: | |
27a5e6d3 HV |
405 | name_base = "vtx"; |
406 | break; | |
407 | case VFL_TYPE_VBI: | |
27a5e6d3 HV |
408 | name_base = "vbi"; |
409 | break; | |
410 | case VFL_TYPE_RADIO: | |
27a5e6d3 HV |
411 | name_base = "radio"; |
412 | break; | |
413 | default: | |
414 | printk(KERN_ERR "%s called with unknown type: %d\n", | |
415 | __func__, type); | |
46f2c21c | 416 | return -EINVAL; |
27a5e6d3 HV |
417 | } |
418 | ||
dc93a70c HV |
419 | vdev->vfl_type = type; |
420 | vdev->cdev = NULL; | |
00575961 | 421 | if (vdev->v4l2_dev && vdev->v4l2_dev->dev) |
9bea3514 | 422 | vdev->parent = vdev->v4l2_dev->dev; |
dd89601d | 423 | |
dc93a70c | 424 | /* Part 2: find a free minor, kernel number and device index. */ |
dd89601d HV |
425 | #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES |
426 | /* Keep the ranges for the first four types for historical | |
427 | * reasons. | |
428 | * Newer devices (not yet in place) should use the range | |
429 | * of 128-191 and just pick the first free minor there | |
430 | * (new style). */ | |
431 | switch (type) { | |
432 | case VFL_TYPE_GRABBER: | |
433 | minor_offset = 0; | |
434 | minor_cnt = 64; | |
435 | break; | |
436 | case VFL_TYPE_RADIO: | |
437 | minor_offset = 64; | |
438 | minor_cnt = 64; | |
439 | break; | |
440 | case VFL_TYPE_VTX: | |
441 | minor_offset = 192; | |
442 | minor_cnt = 32; | |
443 | break; | |
444 | case VFL_TYPE_VBI: | |
445 | minor_offset = 224; | |
446 | minor_cnt = 32; | |
447 | break; | |
448 | default: | |
449 | minor_offset = 128; | |
450 | minor_cnt = 64; | |
451 | break; | |
452 | } | |
453 | #endif | |
454 | ||
dc93a70c | 455 | /* Pick a minor number */ |
27a5e6d3 | 456 | mutex_lock(&videodev_lock); |
dd89601d HV |
457 | nr = find_next_zero_bit(video_nums[type], minor_cnt, nr == -1 ? 0 : nr); |
458 | if (nr == minor_cnt) | |
459 | nr = find_first_zero_bit(video_nums[type], minor_cnt); | |
460 | if (nr == minor_cnt) { | |
461 | printk(KERN_ERR "could not get a free kernel number\n"); | |
462 | mutex_unlock(&videodev_lock); | |
463 | return -ENFILE; | |
27a5e6d3 | 464 | } |
dd89601d HV |
465 | #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES |
466 | /* 1-on-1 mapping of kernel number to minor number */ | |
467 | i = nr; | |
468 | #else | |
469 | /* The kernel number and minor numbers are independent */ | |
470 | for (i = 0; i < VIDEO_NUM_DEVICES; i++) | |
471 | if (video_device[i] == NULL) | |
472 | break; | |
473 | if (i == VIDEO_NUM_DEVICES) { | |
474 | mutex_unlock(&videodev_lock); | |
475 | printk(KERN_ERR "could not get a free minor\n"); | |
476 | return -ENFILE; | |
477 | } | |
478 | #endif | |
dc93a70c HV |
479 | vdev->minor = i + minor_offset; |
480 | vdev->num = nr; | |
dd89601d | 481 | set_bit(nr, video_nums[type]); |
dc93a70c HV |
482 | /* Should not happen since we thought this minor was free */ |
483 | WARN_ON(video_device[vdev->minor] != NULL); | |
484 | ret = vdev->index = get_index(vdev, index); | |
27a5e6d3 HV |
485 | mutex_unlock(&videodev_lock); |
486 | ||
487 | if (ret < 0) { | |
488 | printk(KERN_ERR "%s: get_index failed\n", __func__); | |
dc93a70c | 489 | goto cleanup; |
27a5e6d3 HV |
490 | } |
491 | ||
dc93a70c HV |
492 | /* Part 3: Initialize the character device */ |
493 | vdev->cdev = cdev_alloc(); | |
494 | if (vdev->cdev == NULL) { | |
495 | ret = -ENOMEM; | |
496 | goto cleanup; | |
497 | } | |
498 | if (vdev->fops->unlocked_ioctl) | |
499 | vdev->cdev->ops = &v4l2_unlocked_fops; | |
500 | else | |
501 | vdev->cdev->ops = &v4l2_fops; | |
502 | vdev->cdev->owner = vdev->fops->owner; | |
503 | ret = cdev_add(vdev->cdev, MKDEV(VIDEO_MAJOR, vdev->minor), 1); | |
7f8ecfab HV |
504 | if (ret < 0) { |
505 | printk(KERN_ERR "%s: cdev_add failed\n", __func__); | |
dc93a70c HV |
506 | kfree(vdev->cdev); |
507 | vdev->cdev = NULL; | |
508 | goto cleanup; | |
7f8ecfab | 509 | } |
dc93a70c HV |
510 | |
511 | /* Part 4: register the device with sysfs */ | |
512 | memset(&vdev->dev, 0, sizeof(vdev->dev)); | |
9d95af9d HV |
513 | /* The memset above cleared the device's drvdata, so |
514 | put back the copy we made earlier. */ | |
dc93a70c HV |
515 | video_set_drvdata(vdev, priv); |
516 | vdev->dev.class = &video_class; | |
517 | vdev->dev.devt = MKDEV(VIDEO_MAJOR, vdev->minor); | |
518 | if (vdev->parent) | |
519 | vdev->dev.parent = vdev->parent; | |
520 | dev_set_name(&vdev->dev, "%s%d", name_base, nr); | |
521 | ret = device_register(&vdev->dev); | |
27a5e6d3 HV |
522 | if (ret < 0) { |
523 | printk(KERN_ERR "%s: device_register failed\n", __func__); | |
dc93a70c | 524 | goto cleanup; |
27a5e6d3 | 525 | } |
dc93a70c HV |
526 | /* Register the release callback that will be called when the last |
527 | reference to the device goes away. */ | |
528 | vdev->dev.release = v4l2_device_release; | |
27a5e6d3 | 529 | |
dc93a70c HV |
530 | /* Part 5: Activate this minor. The char device can now be used. */ |
531 | mutex_lock(&videodev_lock); | |
532 | video_device[vdev->minor] = vdev; | |
533 | mutex_unlock(&videodev_lock); | |
534 | return 0; | |
7f8ecfab | 535 | |
dc93a70c | 536 | cleanup: |
27a5e6d3 | 537 | mutex_lock(&videodev_lock); |
dc93a70c HV |
538 | if (vdev->cdev) |
539 | cdev_del(vdev->cdev); | |
540 | clear_bit(vdev->num, video_nums[type]); | |
27a5e6d3 | 541 | mutex_unlock(&videodev_lock); |
dc93a70c HV |
542 | /* Mark this video device as never having been registered. */ |
543 | vdev->minor = -1; | |
27a5e6d3 HV |
544 | return ret; |
545 | } | |
546 | EXPORT_SYMBOL(video_register_device_index); | |
547 | ||
548 | /** | |
549 | * video_unregister_device - unregister a video4linux device | |
dc93a70c | 550 | * @vdev: the device to unregister |
27a5e6d3 | 551 | * |
dc93a70c HV |
552 | * This unregisters the passed device. Future open calls will |
553 | * be met with errors. | |
27a5e6d3 | 554 | */ |
dc93a70c | 555 | void video_unregister_device(struct video_device *vdev) |
27a5e6d3 | 556 | { |
dc93a70c HV |
557 | /* Check if vdev was ever registered at all */ |
558 | if (!vdev || vdev->minor < 0) | |
559 | return; | |
560 | ||
561 | mutex_lock(&videodev_lock); | |
562 | set_bit(V4L2_FL_UNREGISTERED, &vdev->flags); | |
563 | mutex_unlock(&videodev_lock); | |
564 | device_unregister(&vdev->dev); | |
27a5e6d3 HV |
565 | } |
566 | EXPORT_SYMBOL(video_unregister_device); | |
567 | ||
27a5e6d3 HV |
568 | /* |
569 | * Initialise video for linux | |
570 | */ | |
27a5e6d3 HV |
571 | static int __init videodev_init(void) |
572 | { | |
7f8ecfab | 573 | dev_t dev = MKDEV(VIDEO_MAJOR, 0); |
27a5e6d3 HV |
574 | int ret; |
575 | ||
576 | printk(KERN_INFO "Linux video capture interface: v2.00\n"); | |
7f8ecfab HV |
577 | ret = register_chrdev_region(dev, VIDEO_NUM_DEVICES, VIDEO_NAME); |
578 | if (ret < 0) { | |
579 | printk(KERN_WARNING "videodev: unable to get major %d\n", | |
580 | VIDEO_MAJOR); | |
581 | return ret; | |
27a5e6d3 HV |
582 | } |
583 | ||
584 | ret = class_register(&video_class); | |
585 | if (ret < 0) { | |
7f8ecfab | 586 | unregister_chrdev_region(dev, VIDEO_NUM_DEVICES); |
27a5e6d3 HV |
587 | printk(KERN_WARNING "video_dev: class_register failed\n"); |
588 | return -EIO; | |
589 | } | |
590 | ||
591 | return 0; | |
592 | } | |
593 | ||
594 | static void __exit videodev_exit(void) | |
595 | { | |
7f8ecfab HV |
596 | dev_t dev = MKDEV(VIDEO_MAJOR, 0); |
597 | ||
27a5e6d3 | 598 | class_unregister(&video_class); |
7f8ecfab | 599 | unregister_chrdev_region(dev, VIDEO_NUM_DEVICES); |
27a5e6d3 HV |
600 | } |
601 | ||
602 | module_init(videodev_init) | |
603 | module_exit(videodev_exit) | |
604 | ||
605 | MODULE_AUTHOR("Alan Cox, Mauro Carvalho Chehab <mchehab@infradead.org>"); | |
606 | MODULE_DESCRIPTION("Device registrar for Video4Linux drivers v2"); | |
607 | MODULE_LICENSE("GPL"); | |
cbb72b0f | 608 | MODULE_ALIAS_CHARDEV_MAJOR(VIDEO_MAJOR); |
27a5e6d3 HV |
609 | |
610 | ||
611 | /* | |
612 | * Local variables: | |
613 | * c-basic-offset: 8 | |
614 | * End: | |
615 | */ |