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); | |
7f8ecfab HV |
146 | |
147 | mutex_lock(&videodev_lock); | |
dc93a70c | 148 | if (video_device[vdev->minor] != vdev) { |
6ea9a182 | 149 | mutex_unlock(&videodev_lock); |
dc93a70c HV |
150 | /* should not happen */ |
151 | WARN_ON(1); | |
6ea9a182 HV |
152 | return; |
153 | } | |
7f8ecfab HV |
154 | |
155 | /* Free up this device for reuse */ | |
dc93a70c | 156 | video_device[vdev->minor] = NULL; |
7f8ecfab | 157 | |
dc93a70c HV |
158 | /* Delete the cdev on this minor as well */ |
159 | cdev_del(vdev->cdev); | |
160 | /* Just in case some driver tries to access this from | |
161 | the release() callback. */ | |
162 | vdev->cdev = NULL; | |
7f8ecfab | 163 | |
22e22125 | 164 | /* Mark device node number as free */ |
5062cb70 | 165 | devnode_clear(vdev); |
7f8ecfab | 166 | |
dc93a70c | 167 | mutex_unlock(&videodev_lock); |
27a5e6d3 | 168 | |
dc93a70c HV |
169 | /* Release video_device and perform other |
170 | cleanups as needed. */ | |
171 | vdev->release(vdev); | |
27a5e6d3 HV |
172 | } |
173 | ||
174 | static struct class video_class = { | |
175 | .name = VIDEO_NAME, | |
176 | .dev_attrs = video_device_attrs, | |
27a5e6d3 HV |
177 | }; |
178 | ||
27a5e6d3 HV |
179 | struct video_device *video_devdata(struct file *file) |
180 | { | |
181 | return video_device[iminor(file->f_path.dentry->d_inode)]; | |
182 | } | |
183 | EXPORT_SYMBOL(video_devdata); | |
184 | ||
dc93a70c HV |
185 | static ssize_t v4l2_read(struct file *filp, char __user *buf, |
186 | size_t sz, loff_t *off) | |
187 | { | |
188 | struct video_device *vdev = video_devdata(filp); | |
2877842d | 189 | int ret = -ENODEV; |
dc93a70c HV |
190 | |
191 | if (!vdev->fops->read) | |
192 | return -EINVAL; | |
2877842d HV |
193 | if (vdev->lock && mutex_lock_interruptible(vdev->lock)) |
194 | return -ERESTARTSYS; | |
ee6869af HV |
195 | if (video_is_registered(vdev)) |
196 | ret = vdev->fops->read(filp, buf, sz, off); | |
197 | if (vdev->lock) | |
198 | mutex_unlock(vdev->lock); | |
199 | return ret; | |
dc93a70c HV |
200 | } |
201 | ||
202 | static ssize_t v4l2_write(struct file *filp, const char __user *buf, | |
203 | size_t sz, loff_t *off) | |
204 | { | |
205 | struct video_device *vdev = video_devdata(filp); | |
2877842d | 206 | int ret = -ENODEV; |
dc93a70c HV |
207 | |
208 | if (!vdev->fops->write) | |
209 | return -EINVAL; | |
2877842d HV |
210 | if (vdev->lock && mutex_lock_interruptible(vdev->lock)) |
211 | return -ERESTARTSYS; | |
ee6869af HV |
212 | if (video_is_registered(vdev)) |
213 | ret = vdev->fops->write(filp, buf, sz, off); | |
214 | if (vdev->lock) | |
215 | mutex_unlock(vdev->lock); | |
216 | return ret; | |
dc93a70c HV |
217 | } |
218 | ||
219 | static unsigned int v4l2_poll(struct file *filp, struct poll_table_struct *poll) | |
220 | { | |
221 | struct video_device *vdev = video_devdata(filp); | |
2877842d | 222 | int ret = POLLERR | POLLHUP; |
ee6869af HV |
223 | |
224 | if (!vdev->fops->poll) | |
2877842d | 225 | return DEFAULT_POLLMASK; |
ee6869af HV |
226 | if (vdev->lock) |
227 | mutex_lock(vdev->lock); | |
228 | if (video_is_registered(vdev)) | |
229 | ret = vdev->fops->poll(filp, poll); | |
230 | if (vdev->lock) | |
231 | mutex_unlock(vdev->lock); | |
232 | return ret; | |
dc93a70c HV |
233 | } |
234 | ||
86a5ef7d | 235 | static long v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) |
dc93a70c HV |
236 | { |
237 | struct video_device *vdev = video_devdata(filp); | |
72420630 | 238 | int ret = -ENODEV; |
dc93a70c | 239 | |
86a5ef7d | 240 | if (vdev->fops->unlocked_ioctl) { |
2877842d HV |
241 | if (vdev->lock && mutex_lock_interruptible(vdev->lock)) |
242 | return -ERESTARTSYS; | |
72420630 MCC |
243 | if (video_is_registered(vdev)) |
244 | ret = vdev->fops->unlocked_ioctl(filp, cmd, arg); | |
ee6869af HV |
245 | if (vdev->lock) |
246 | mutex_unlock(vdev->lock); | |
86a5ef7d | 247 | } else if (vdev->fops->ioctl) { |
879aa24d HV |
248 | /* This code path is a replacement for the BKL. It is a major |
249 | * hack but it will have to do for those drivers that are not | |
250 | * yet converted to use unlocked_ioctl. | |
251 | * | |
252 | * There are two options: if the driver implements struct | |
253 | * v4l2_device, then the lock defined there is used to | |
254 | * serialize the ioctls. Otherwise the v4l2 core lock defined | |
255 | * below is used. This lock is really bad since it serializes | |
256 | * completely independent devices. | |
257 | * | |
258 | * Both variants suffer from the same problem: if the driver | |
259 | * sleeps, then it blocks all ioctls since the lock is still | |
260 | * held. This is very common for VIDIOC_DQBUF since that | |
261 | * normally waits for a frame to arrive. As a result any other | |
262 | * ioctl calls will proceed very, very slowly since each call | |
263 | * will have to wait for the VIDIOC_QBUF to finish. Things that | |
264 | * should take 0.01s may now take 10-20 seconds. | |
265 | * | |
266 | * The workaround is to *not* take the lock for VIDIOC_DQBUF. | |
267 | * This actually works OK for videobuf-based drivers, since | |
268 | * videobuf will take its own internal lock. | |
269 | */ | |
0edf2e5e | 270 | static DEFINE_MUTEX(v4l2_ioctl_mutex); |
879aa24d HV |
271 | struct mutex *m = vdev->v4l2_dev ? |
272 | &vdev->v4l2_dev->ioctl_lock : &v4l2_ioctl_mutex; | |
0edf2e5e | 273 | |
879aa24d HV |
274 | if (cmd != VIDIOC_DQBUF && mutex_lock_interruptible(m)) |
275 | return -ERESTARTSYS; | |
72420630 MCC |
276 | if (video_is_registered(vdev)) |
277 | ret = vdev->fops->ioctl(filp, cmd, arg); | |
879aa24d HV |
278 | if (cmd != VIDIOC_DQBUF) |
279 | mutex_unlock(m); | |
86a5ef7d AB |
280 | } else |
281 | ret = -ENOTTY; | |
dc93a70c | 282 | |
86a5ef7d | 283 | return ret; |
dc93a70c HV |
284 | } |
285 | ||
dc93a70c HV |
286 | static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm) |
287 | { | |
288 | struct video_device *vdev = video_devdata(filp); | |
ee6869af HV |
289 | int ret = -ENODEV; |
290 | ||
291 | if (!vdev->fops->mmap) | |
292 | return ret; | |
2877842d HV |
293 | if (vdev->lock && mutex_lock_interruptible(vdev->lock)) |
294 | return -ERESTARTSYS; | |
ee6869af HV |
295 | if (video_is_registered(vdev)) |
296 | ret = vdev->fops->mmap(filp, vm); | |
297 | if (vdev->lock) | |
298 | mutex_unlock(vdev->lock); | |
299 | return ret; | |
dc93a70c HV |
300 | } |
301 | ||
302 | /* Override for the open function */ | |
303 | static int v4l2_open(struct inode *inode, struct file *filp) | |
304 | { | |
305 | struct video_device *vdev; | |
65d9ff9c | 306 | int ret = 0; |
dc93a70c HV |
307 | |
308 | /* Check if the video device is available */ | |
309 | mutex_lock(&videodev_lock); | |
310 | vdev = video_devdata(filp); | |
ee6869af | 311 | /* return ENODEV if the video device has already been removed. */ |
ca9afe6f | 312 | if (vdev == NULL || !video_is_registered(vdev)) { |
dc93a70c HV |
313 | mutex_unlock(&videodev_lock); |
314 | return -ENODEV; | |
315 | } | |
316 | /* and increase the device refcount */ | |
317 | video_get(vdev); | |
318 | mutex_unlock(&videodev_lock); | |
ee6869af | 319 | if (vdev->fops->open) { |
2877842d HV |
320 | if (vdev->lock && mutex_lock_interruptible(vdev->lock)) { |
321 | ret = -ERESTARTSYS; | |
322 | goto err; | |
323 | } | |
ee6869af HV |
324 | if (video_is_registered(vdev)) |
325 | ret = vdev->fops->open(filp); | |
326 | else | |
327 | ret = -ENODEV; | |
328 | if (vdev->lock) | |
329 | mutex_unlock(vdev->lock); | |
330 | } | |
65d9ff9c | 331 | |
2877842d | 332 | err: |
dc93a70c HV |
333 | /* decrease the refcount in case of an error */ |
334 | if (ret) | |
335 | video_put(vdev); | |
336 | return ret; | |
337 | } | |
338 | ||
339 | /* Override for the release function */ | |
340 | static int v4l2_release(struct inode *inode, struct file *filp) | |
341 | { | |
342 | struct video_device *vdev = video_devdata(filp); | |
65d9ff9c HV |
343 | int ret = 0; |
344 | ||
ee6869af HV |
345 | if (vdev->fops->release) { |
346 | if (vdev->lock) | |
347 | mutex_lock(vdev->lock); | |
65d9ff9c | 348 | vdev->fops->release(filp); |
ee6869af HV |
349 | if (vdev->lock) |
350 | mutex_unlock(vdev->lock); | |
351 | } | |
dc93a70c HV |
352 | |
353 | /* decrease the refcount unconditionally since the release() | |
354 | return value is ignored. */ | |
355 | video_put(vdev); | |
356 | return ret; | |
357 | } | |
358 | ||
dc93a70c HV |
359 | static const struct file_operations v4l2_fops = { |
360 | .owner = THIS_MODULE, | |
361 | .read = v4l2_read, | |
362 | .write = v4l2_write, | |
363 | .open = v4l2_open, | |
364 | .mmap = v4l2_mmap, | |
86a5ef7d | 365 | .unlocked_ioctl = v4l2_ioctl, |
dc93a70c | 366 | #ifdef CONFIG_COMPAT |
9bb7cde7 | 367 | .compat_ioctl = v4l2_compat_ioctl32, |
dc93a70c HV |
368 | #endif |
369 | .release = v4l2_release, | |
370 | .poll = v4l2_poll, | |
371 | .llseek = no_llseek, | |
372 | }; | |
373 | ||
27a5e6d3 | 374 | /** |
7ae0cd9b | 375 | * get_index - assign stream index number based on parent device |
dc93a70c | 376 | * @vdev: video_device to assign index number to, vdev->parent should be assigned |
27a5e6d3 | 377 | * |
dc93a70c | 378 | * Note that when this is called the new device has not yet been registered |
7ae0cd9b | 379 | * in the video_device array, but it was able to obtain a minor number. |
27a5e6d3 | 380 | * |
7ae0cd9b HV |
381 | * This means that we can always obtain a free stream index number since |
382 | * the worst case scenario is that there are VIDEO_NUM_DEVICES - 1 slots in | |
383 | * use of the video_device array. | |
384 | * | |
385 | * Returns a free index number. | |
27a5e6d3 | 386 | */ |
7ae0cd9b | 387 | static int get_index(struct video_device *vdev) |
27a5e6d3 | 388 | { |
775a05dd HV |
389 | /* This can be static since this function is called with the global |
390 | videodev_lock held. */ | |
391 | static DECLARE_BITMAP(used, VIDEO_NUM_DEVICES); | |
27a5e6d3 HV |
392 | int i; |
393 | ||
7ae0cd9b | 394 | /* Some drivers do not set the parent. In that case always return 0. */ |
806e5b7c | 395 | if (vdev->parent == NULL) |
7ae0cd9b | 396 | return 0; |
775a05dd HV |
397 | |
398 | bitmap_zero(used, VIDEO_NUM_DEVICES); | |
806e5b7c | 399 | |
27a5e6d3 HV |
400 | for (i = 0; i < VIDEO_NUM_DEVICES; i++) { |
401 | if (video_device[i] != NULL && | |
5e85e732 | 402 | video_device[i]->parent == vdev->parent) { |
775a05dd | 403 | set_bit(video_device[i]->index, used); |
27a5e6d3 HV |
404 | } |
405 | } | |
406 | ||
7ae0cd9b | 407 | return find_first_zero_bit(used, VIDEO_NUM_DEVICES); |
27a5e6d3 HV |
408 | } |
409 | ||
27a5e6d3 | 410 | /** |
2096a5dc | 411 | * __video_register_device - register video4linux devices |
dc93a70c | 412 | * @vdev: video device structure we want to register |
27a5e6d3 | 413 | * @type: type of device to register |
22e22125 | 414 | * @nr: which device node number (0 == /dev/video0, 1 == /dev/video1, ... |
27a5e6d3 | 415 | * -1 == first free) |
6b5270d2 HV |
416 | * @warn_if_nr_in_use: warn if the desired device node number |
417 | * was already in use and another number was chosen instead. | |
2096a5dc | 418 | * @owner: module that owns the video device node |
27a5e6d3 | 419 | * |
22e22125 HV |
420 | * The registration code assigns minor numbers and device node numbers |
421 | * based on the requested type and registers the new device node with | |
422 | * the kernel. | |
46b63377 HV |
423 | * |
424 | * This function assumes that struct video_device was zeroed when it | |
425 | * was allocated and does not contain any stale date. | |
426 | * | |
22e22125 HV |
427 | * An error is returned if no free minor or device node number could be |
428 | * found, or if the registration of the device node failed. | |
27a5e6d3 HV |
429 | * |
430 | * Zero is returned on success. | |
431 | * | |
432 | * Valid types are | |
433 | * | |
434 | * %VFL_TYPE_GRABBER - A frame grabber | |
435 | * | |
27a5e6d3 HV |
436 | * %VFL_TYPE_VBI - Vertical blank data (undecoded) |
437 | * | |
438 | * %VFL_TYPE_RADIO - A radio card | |
2096a5dc LP |
439 | * |
440 | * %VFL_TYPE_SUBDEV - A subdevice | |
27a5e6d3 | 441 | */ |
2096a5dc LP |
442 | int __video_register_device(struct video_device *vdev, int type, int nr, |
443 | int warn_if_nr_in_use, struct module *owner) | |
27a5e6d3 HV |
444 | { |
445 | int i = 0; | |
27a5e6d3 | 446 | int ret; |
dd89601d HV |
447 | int minor_offset = 0; |
448 | int minor_cnt = VIDEO_NUM_DEVICES; | |
449 | const char *name_base; | |
27a5e6d3 | 450 | |
dc93a70c HV |
451 | /* A minor value of -1 marks this video device as never |
452 | having been registered */ | |
428c8d19 | 453 | vdev->minor = -1; |
ee7aa9f8 | 454 | |
dc93a70c | 455 | /* the release callback MUST be present */ |
428c8d19 TP |
456 | WARN_ON(!vdev->release); |
457 | if (!vdev->release) | |
f3b9f50e HK |
458 | return -EINVAL; |
459 | ||
1babcb46 SA |
460 | /* v4l2_fh support */ |
461 | spin_lock_init(&vdev->fh_lock); | |
462 | INIT_LIST_HEAD(&vdev->fh_list); | |
463 | ||
dc93a70c | 464 | /* Part 1: check device type */ |
27a5e6d3 HV |
465 | switch (type) { |
466 | case VFL_TYPE_GRABBER: | |
27a5e6d3 HV |
467 | name_base = "video"; |
468 | break; | |
27a5e6d3 | 469 | case VFL_TYPE_VBI: |
27a5e6d3 HV |
470 | name_base = "vbi"; |
471 | break; | |
472 | case VFL_TYPE_RADIO: | |
27a5e6d3 HV |
473 | name_base = "radio"; |
474 | break; | |
2096a5dc LP |
475 | case VFL_TYPE_SUBDEV: |
476 | name_base = "v4l-subdev"; | |
477 | break; | |
27a5e6d3 HV |
478 | default: |
479 | printk(KERN_ERR "%s called with unknown type: %d\n", | |
480 | __func__, type); | |
46f2c21c | 481 | return -EINVAL; |
27a5e6d3 HV |
482 | } |
483 | ||
dc93a70c HV |
484 | vdev->vfl_type = type; |
485 | vdev->cdev = NULL; | |
11bbc1ca HV |
486 | if (vdev->v4l2_dev) { |
487 | if (vdev->v4l2_dev->dev) | |
488 | vdev->parent = vdev->v4l2_dev->dev; | |
489 | if (vdev->ctrl_handler == NULL) | |
490 | vdev->ctrl_handler = vdev->v4l2_dev->ctrl_handler; | |
491 | } | |
dd89601d | 492 | |
22e22125 | 493 | /* Part 2: find a free minor, device node number and device index. */ |
dd89601d HV |
494 | #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES |
495 | /* Keep the ranges for the first four types for historical | |
496 | * reasons. | |
497 | * Newer devices (not yet in place) should use the range | |
498 | * of 128-191 and just pick the first free minor there | |
499 | * (new style). */ | |
500 | switch (type) { | |
501 | case VFL_TYPE_GRABBER: | |
502 | minor_offset = 0; | |
503 | minor_cnt = 64; | |
504 | break; | |
505 | case VFL_TYPE_RADIO: | |
506 | minor_offset = 64; | |
507 | minor_cnt = 64; | |
508 | break; | |
dd89601d HV |
509 | case VFL_TYPE_VBI: |
510 | minor_offset = 224; | |
511 | minor_cnt = 32; | |
512 | break; | |
513 | default: | |
514 | minor_offset = 128; | |
515 | minor_cnt = 64; | |
516 | break; | |
517 | } | |
518 | #endif | |
519 | ||
22e22125 | 520 | /* Pick a device node number */ |
27a5e6d3 | 521 | mutex_lock(&videodev_lock); |
5062cb70 | 522 | nr = devnode_find(vdev, nr == -1 ? 0 : nr, minor_cnt); |
dd89601d | 523 | if (nr == minor_cnt) |
5062cb70 | 524 | nr = devnode_find(vdev, 0, minor_cnt); |
dd89601d | 525 | if (nr == minor_cnt) { |
22e22125 | 526 | printk(KERN_ERR "could not get a free device node number\n"); |
dd89601d HV |
527 | mutex_unlock(&videodev_lock); |
528 | return -ENFILE; | |
27a5e6d3 | 529 | } |
dd89601d | 530 | #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES |
22e22125 | 531 | /* 1-on-1 mapping of device node number to minor number */ |
dd89601d HV |
532 | i = nr; |
533 | #else | |
22e22125 HV |
534 | /* The device node number and minor numbers are independent, so |
535 | we just find the first free minor number. */ | |
dd89601d HV |
536 | for (i = 0; i < VIDEO_NUM_DEVICES; i++) |
537 | if (video_device[i] == NULL) | |
538 | break; | |
539 | if (i == VIDEO_NUM_DEVICES) { | |
540 | mutex_unlock(&videodev_lock); | |
541 | printk(KERN_ERR "could not get a free minor\n"); | |
542 | return -ENFILE; | |
543 | } | |
544 | #endif | |
dc93a70c HV |
545 | vdev->minor = i + minor_offset; |
546 | vdev->num = nr; | |
5062cb70 HV |
547 | devnode_set(vdev); |
548 | ||
dc93a70c HV |
549 | /* Should not happen since we thought this minor was free */ |
550 | WARN_ON(video_device[vdev->minor] != NULL); | |
7ae0cd9b | 551 | vdev->index = get_index(vdev); |
27a5e6d3 HV |
552 | mutex_unlock(&videodev_lock); |
553 | ||
dc93a70c HV |
554 | /* Part 3: Initialize the character device */ |
555 | vdev->cdev = cdev_alloc(); | |
556 | if (vdev->cdev == NULL) { | |
557 | ret = -ENOMEM; | |
558 | goto cleanup; | |
559 | } | |
86a5ef7d | 560 | vdev->cdev->ops = &v4l2_fops; |
2096a5dc | 561 | vdev->cdev->owner = owner; |
dc93a70c | 562 | ret = cdev_add(vdev->cdev, MKDEV(VIDEO_MAJOR, vdev->minor), 1); |
7f8ecfab HV |
563 | if (ret < 0) { |
564 | printk(KERN_ERR "%s: cdev_add failed\n", __func__); | |
dc93a70c HV |
565 | kfree(vdev->cdev); |
566 | vdev->cdev = NULL; | |
567 | goto cleanup; | |
7f8ecfab | 568 | } |
dc93a70c HV |
569 | |
570 | /* Part 4: register the device with sysfs */ | |
dc93a70c HV |
571 | vdev->dev.class = &video_class; |
572 | vdev->dev.devt = MKDEV(VIDEO_MAJOR, vdev->minor); | |
573 | if (vdev->parent) | |
574 | vdev->dev.parent = vdev->parent; | |
22e22125 | 575 | dev_set_name(&vdev->dev, "%s%d", name_base, vdev->num); |
dc93a70c | 576 | ret = device_register(&vdev->dev); |
27a5e6d3 HV |
577 | if (ret < 0) { |
578 | printk(KERN_ERR "%s: device_register failed\n", __func__); | |
dc93a70c | 579 | goto cleanup; |
27a5e6d3 | 580 | } |
dc93a70c HV |
581 | /* Register the release callback that will be called when the last |
582 | reference to the device goes away. */ | |
583 | vdev->dev.release = v4l2_device_release; | |
27a5e6d3 | 584 | |
6b5270d2 | 585 | if (nr != -1 && nr != vdev->num && warn_if_nr_in_use) |
eac8ea53 LP |
586 | printk(KERN_WARNING "%s: requested %s%d, got %s\n", __func__, |
587 | name_base, nr, video_device_node_name(vdev)); | |
6b5270d2 | 588 | |
dc93a70c | 589 | /* Part 5: Activate this minor. The char device can now be used. */ |
957b4aa9 | 590 | set_bit(V4L2_FL_REGISTERED, &vdev->flags); |
dc93a70c HV |
591 | mutex_lock(&videodev_lock); |
592 | video_device[vdev->minor] = vdev; | |
593 | mutex_unlock(&videodev_lock); | |
594 | return 0; | |
7f8ecfab | 595 | |
dc93a70c | 596 | cleanup: |
27a5e6d3 | 597 | mutex_lock(&videodev_lock); |
dc93a70c HV |
598 | if (vdev->cdev) |
599 | cdev_del(vdev->cdev); | |
5062cb70 | 600 | devnode_clear(vdev); |
27a5e6d3 | 601 | mutex_unlock(&videodev_lock); |
dc93a70c HV |
602 | /* Mark this video device as never having been registered. */ |
603 | vdev->minor = -1; | |
27a5e6d3 HV |
604 | return ret; |
605 | } | |
2096a5dc | 606 | EXPORT_SYMBOL(__video_register_device); |
6b5270d2 | 607 | |
27a5e6d3 HV |
608 | /** |
609 | * video_unregister_device - unregister a video4linux device | |
dc93a70c | 610 | * @vdev: the device to unregister |
27a5e6d3 | 611 | * |
dc93a70c HV |
612 | * This unregisters the passed device. Future open calls will |
613 | * be met with errors. | |
27a5e6d3 | 614 | */ |
dc93a70c | 615 | void video_unregister_device(struct video_device *vdev) |
27a5e6d3 | 616 | { |
dc93a70c | 617 | /* Check if vdev was ever registered at all */ |
957b4aa9 | 618 | if (!vdev || !video_is_registered(vdev)) |
dc93a70c HV |
619 | return; |
620 | ||
ca9afe6f HV |
621 | mutex_lock(&videodev_lock); |
622 | /* This must be in a critical section to prevent a race with v4l2_open. | |
623 | * Once this bit has been cleared video_get may never be called again. | |
624 | */ | |
957b4aa9 | 625 | clear_bit(V4L2_FL_REGISTERED, &vdev->flags); |
ca9afe6f | 626 | mutex_unlock(&videodev_lock); |
dc93a70c | 627 | device_unregister(&vdev->dev); |
27a5e6d3 HV |
628 | } |
629 | EXPORT_SYMBOL(video_unregister_device); | |
630 | ||
27a5e6d3 HV |
631 | /* |
632 | * Initialise video for linux | |
633 | */ | |
27a5e6d3 HV |
634 | static int __init videodev_init(void) |
635 | { | |
7f8ecfab | 636 | dev_t dev = MKDEV(VIDEO_MAJOR, 0); |
27a5e6d3 HV |
637 | int ret; |
638 | ||
639 | printk(KERN_INFO "Linux video capture interface: v2.00\n"); | |
7f8ecfab HV |
640 | ret = register_chrdev_region(dev, VIDEO_NUM_DEVICES, VIDEO_NAME); |
641 | if (ret < 0) { | |
642 | printk(KERN_WARNING "videodev: unable to get major %d\n", | |
643 | VIDEO_MAJOR); | |
644 | return ret; | |
27a5e6d3 HV |
645 | } |
646 | ||
647 | ret = class_register(&video_class); | |
648 | if (ret < 0) { | |
7f8ecfab | 649 | unregister_chrdev_region(dev, VIDEO_NUM_DEVICES); |
27a5e6d3 HV |
650 | printk(KERN_WARNING "video_dev: class_register failed\n"); |
651 | return -EIO; | |
652 | } | |
653 | ||
654 | return 0; | |
655 | } | |
656 | ||
657 | static void __exit videodev_exit(void) | |
658 | { | |
7f8ecfab HV |
659 | dev_t dev = MKDEV(VIDEO_MAJOR, 0); |
660 | ||
27a5e6d3 | 661 | class_unregister(&video_class); |
7f8ecfab | 662 | unregister_chrdev_region(dev, VIDEO_NUM_DEVICES); |
27a5e6d3 HV |
663 | } |
664 | ||
665 | module_init(videodev_init) | |
666 | module_exit(videodev_exit) | |
667 | ||
668 | MODULE_AUTHOR("Alan Cox, Mauro Carvalho Chehab <mchehab@infradead.org>"); | |
669 | MODULE_DESCRIPTION("Device registrar for Video4Linux drivers v2"); | |
670 | MODULE_LICENSE("GPL"); | |
cbb72b0f | 671 | MODULE_ALIAS_CHARDEV_MAJOR(VIDEO_MAJOR); |
27a5e6d3 HV |
672 | |
673 | ||
674 | /* | |
675 | * Local variables: | |
676 | * c-basic-offset: 8 | |
677 | * End: | |
678 | */ |