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  *
12  * Authors:	Alan Cox, <alan@lxorguk.ukuu.org.uk> (version 1)
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/uaccess.h>
29 
30 #include <media/v4l2-common.h>
31 #include <media/v4l2-device.h>
32 #include <media/v4l2-ioctl.h>
33 
34 #define VIDEO_NUM_DEVICES	256
35 #define VIDEO_NAME              "video4linux"
36 
37 /*
38  *	sysfs stuff
39  */
40 
41 static ssize_t index_show(struct device *cd,
42 			  struct device_attribute *attr, char *buf)
43 {
44 	struct video_device *vdev = to_video_device(cd);
45 
46 	return sprintf(buf, "%i\n", vdev->index);
47 }
48 static DEVICE_ATTR_RO(index);
49 
50 static ssize_t dev_debug_show(struct device *cd,
51 			  struct device_attribute *attr, char *buf)
52 {
53 	struct video_device *vdev = to_video_device(cd);
54 
55 	return sprintf(buf, "%i\n", vdev->dev_debug);
56 }
57 
58 static ssize_t dev_debug_store(struct device *cd, struct device_attribute *attr,
59 			  const char *buf, size_t len)
60 {
61 	struct video_device *vdev = to_video_device(cd);
62 	int res = 0;
63 	u16 value;
64 
65 	res = kstrtou16(buf, 0, &value);
66 	if (res)
67 		return res;
68 
69 	vdev->dev_debug = value;
70 	return len;
71 }
72 static DEVICE_ATTR_RW(dev_debug);
73 
74 static ssize_t name_show(struct device *cd,
75 			 struct device_attribute *attr, char *buf)
76 {
77 	struct video_device *vdev = to_video_device(cd);
78 
79 	return sprintf(buf, "%.*s\n", (int)sizeof(vdev->name), vdev->name);
80 }
81 static DEVICE_ATTR_RO(name);
82 
83 static struct attribute *video_device_attrs[] = {
84 	&dev_attr_name.attr,
85 	&dev_attr_dev_debug.attr,
86 	&dev_attr_index.attr,
87 	NULL,
88 };
89 ATTRIBUTE_GROUPS(video_device);
90 
91 /*
92  *	Active devices
93  */
94 static struct video_device *video_device[VIDEO_NUM_DEVICES];
95 static DEFINE_MUTEX(videodev_lock);
96 static DECLARE_BITMAP(devnode_nums[VFL_TYPE_MAX], VIDEO_NUM_DEVICES);
97 
98 /* Device node utility functions */
99 
100 /* Note: these utility functions all assume that vfl_type is in the range
101    [0, VFL_TYPE_MAX-1]. */
102 
103 #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
104 /* Return the bitmap corresponding to vfl_type. */
105 static inline unsigned long *devnode_bits(enum vfl_devnode_type vfl_type)
106 {
107 	/* Any types not assigned to fixed minor ranges must be mapped to
108 	   one single bitmap for the purposes of finding a free node number
109 	   since all those unassigned types use the same minor range. */
110 	int idx = (vfl_type > VFL_TYPE_RADIO) ? VFL_TYPE_MAX - 1 : vfl_type;
111 
112 	return devnode_nums[idx];
113 }
114 #else
115 /* Return the bitmap corresponding to vfl_type. */
116 static inline unsigned long *devnode_bits(enum vfl_devnode_type vfl_type)
117 {
118 	return devnode_nums[vfl_type];
119 }
120 #endif
121 
122 /* Mark device node number vdev->num as used */
123 static inline void devnode_set(struct video_device *vdev)
124 {
125 	set_bit(vdev->num, devnode_bits(vdev->vfl_type));
126 }
127 
128 /* Mark device node number vdev->num as unused */
129 static inline void devnode_clear(struct video_device *vdev)
130 {
131 	clear_bit(vdev->num, devnode_bits(vdev->vfl_type));
132 }
133 
134 /* Try to find a free device node number in the range [from, to> */
135 static inline int devnode_find(struct video_device *vdev, int from, int to)
136 {
137 	return find_next_zero_bit(devnode_bits(vdev->vfl_type), to, from);
138 }
139 
140 struct video_device *video_device_alloc(void)
141 {
142 	return kzalloc(sizeof(struct video_device), GFP_KERNEL);
143 }
144 EXPORT_SYMBOL(video_device_alloc);
145 
146 void video_device_release(struct video_device *vdev)
147 {
148 	kfree(vdev);
149 }
150 EXPORT_SYMBOL(video_device_release);
151 
152 void video_device_release_empty(struct video_device *vdev)
153 {
154 	/* Do nothing */
155 	/* Only valid when the video_device struct is a static. */
156 }
157 EXPORT_SYMBOL(video_device_release_empty);
158 
159 static inline void video_get(struct video_device *vdev)
160 {
161 	get_device(&vdev->dev);
162 }
163 
164 static inline void video_put(struct video_device *vdev)
165 {
166 	put_device(&vdev->dev);
167 }
168 
169 /* Called when the last user of the video device exits. */
170 static void v4l2_device_release(struct device *cd)
171 {
172 	struct video_device *vdev = to_video_device(cd);
173 	struct v4l2_device *v4l2_dev = vdev->v4l2_dev;
174 
175 	mutex_lock(&videodev_lock);
176 	if (WARN_ON(video_device[vdev->minor] != vdev)) {
177 		/* should not happen */
178 		mutex_unlock(&videodev_lock);
179 		return;
180 	}
181 
182 	/* Free up this device for reuse */
183 	video_device[vdev->minor] = NULL;
184 
185 	/* Delete the cdev on this minor as well */
186 	cdev_del(vdev->cdev);
187 	/* Just in case some driver tries to access this from
188 	   the release() callback. */
189 	vdev->cdev = NULL;
190 
191 	/* Mark device node number as free */
192 	devnode_clear(vdev);
193 
194 	mutex_unlock(&videodev_lock);
195 
196 #if defined(CONFIG_MEDIA_CONTROLLER)
197 	if (v4l2_dev->mdev) {
198 		/* Remove interfaces and interface links */
199 		media_devnode_remove(vdev->intf_devnode);
200 		if (vdev->entity.function != MEDIA_ENT_F_UNKNOWN)
201 			media_device_unregister_entity(&vdev->entity);
202 	}
203 #endif
204 
205 	/* Do not call v4l2_device_put if there is no release callback set.
206 	 * Drivers that have no v4l2_device release callback might free the
207 	 * v4l2_dev instance in the video_device release callback below, so we
208 	 * must perform this check here.
209 	 *
210 	 * TODO: In the long run all drivers that use v4l2_device should use the
211 	 * v4l2_device release callback. This check will then be unnecessary.
212 	 */
213 	if (v4l2_dev->release == NULL)
214 		v4l2_dev = NULL;
215 
216 	/* Release video_device and perform other
217 	   cleanups as needed. */
218 	vdev->release(vdev);
219 
220 	/* Decrease v4l2_device refcount */
221 	if (v4l2_dev)
222 		v4l2_device_put(v4l2_dev);
223 }
224 
225 static struct class video_class = {
226 	.name = VIDEO_NAME,
227 	.dev_groups = video_device_groups,
228 };
229 
230 struct video_device *video_devdata(struct file *file)
231 {
232 	return video_device[iminor(file_inode(file))];
233 }
234 EXPORT_SYMBOL(video_devdata);
235 
236 
237 /* Priority handling */
238 
239 static inline bool prio_is_valid(enum v4l2_priority prio)
240 {
241 	return prio == V4L2_PRIORITY_BACKGROUND ||
242 	       prio == V4L2_PRIORITY_INTERACTIVE ||
243 	       prio == V4L2_PRIORITY_RECORD;
244 }
245 
246 void v4l2_prio_init(struct v4l2_prio_state *global)
247 {
248 	memset(global, 0, sizeof(*global));
249 }
250 EXPORT_SYMBOL(v4l2_prio_init);
251 
252 int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
253 		     enum v4l2_priority new)
254 {
255 	if (!prio_is_valid(new))
256 		return -EINVAL;
257 	if (*local == new)
258 		return 0;
259 
260 	atomic_inc(&global->prios[new]);
261 	if (prio_is_valid(*local))
262 		atomic_dec(&global->prios[*local]);
263 	*local = new;
264 	return 0;
265 }
266 EXPORT_SYMBOL(v4l2_prio_change);
267 
268 void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local)
269 {
270 	v4l2_prio_change(global, local, V4L2_PRIORITY_DEFAULT);
271 }
272 EXPORT_SYMBOL(v4l2_prio_open);
273 
274 void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local)
275 {
276 	if (prio_is_valid(local))
277 		atomic_dec(&global->prios[local]);
278 }
279 EXPORT_SYMBOL(v4l2_prio_close);
280 
281 enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global)
282 {
283 	if (atomic_read(&global->prios[V4L2_PRIORITY_RECORD]) > 0)
284 		return V4L2_PRIORITY_RECORD;
285 	if (atomic_read(&global->prios[V4L2_PRIORITY_INTERACTIVE]) > 0)
286 		return V4L2_PRIORITY_INTERACTIVE;
287 	if (atomic_read(&global->prios[V4L2_PRIORITY_BACKGROUND]) > 0)
288 		return V4L2_PRIORITY_BACKGROUND;
289 	return V4L2_PRIORITY_UNSET;
290 }
291 EXPORT_SYMBOL(v4l2_prio_max);
292 
293 int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local)
294 {
295 	return (local < v4l2_prio_max(global)) ? -EBUSY : 0;
296 }
297 EXPORT_SYMBOL(v4l2_prio_check);
298 
299 
300 static ssize_t v4l2_read(struct file *filp, char __user *buf,
301 		size_t sz, loff_t *off)
302 {
303 	struct video_device *vdev = video_devdata(filp);
304 	int ret = -ENODEV;
305 
306 	if (!vdev->fops->read)
307 		return -EINVAL;
308 	if (video_is_registered(vdev))
309 		ret = vdev->fops->read(filp, buf, sz, off);
310 	if ((vdev->dev_debug & V4L2_DEV_DEBUG_FOP) &&
311 	    (vdev->dev_debug & V4L2_DEV_DEBUG_STREAMING))
312 		printk(KERN_DEBUG "%s: read: %zd (%d)\n",
313 			video_device_node_name(vdev), sz, ret);
314 	return ret;
315 }
316 
317 static ssize_t v4l2_write(struct file *filp, const char __user *buf,
318 		size_t sz, loff_t *off)
319 {
320 	struct video_device *vdev = video_devdata(filp);
321 	int ret = -ENODEV;
322 
323 	if (!vdev->fops->write)
324 		return -EINVAL;
325 	if (video_is_registered(vdev))
326 		ret = vdev->fops->write(filp, buf, sz, off);
327 	if ((vdev->dev_debug & V4L2_DEV_DEBUG_FOP) &&
328 	    (vdev->dev_debug & V4L2_DEV_DEBUG_STREAMING))
329 		printk(KERN_DEBUG "%s: write: %zd (%d)\n",
330 			video_device_node_name(vdev), sz, ret);
331 	return ret;
332 }
333 
334 static __poll_t v4l2_poll(struct file *filp, struct poll_table_struct *poll)
335 {
336 	struct video_device *vdev = video_devdata(filp);
337 	__poll_t res = EPOLLERR | EPOLLHUP;
338 
339 	if (!vdev->fops->poll)
340 		return DEFAULT_POLLMASK;
341 	if (video_is_registered(vdev))
342 		res = vdev->fops->poll(filp, poll);
343 	if (vdev->dev_debug & V4L2_DEV_DEBUG_POLL)
344 		printk(KERN_DEBUG "%s: poll: %08x\n",
345 			video_device_node_name(vdev), res);
346 	return res;
347 }
348 
349 static long v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
350 {
351 	struct video_device *vdev = video_devdata(filp);
352 	int ret = -ENODEV;
353 
354 	if (vdev->fops->unlocked_ioctl) {
355 		struct mutex *lock = v4l2_ioctl_get_lock(vdev, cmd);
356 
357 		if (lock && mutex_lock_interruptible(lock))
358 			return -ERESTARTSYS;
359 		if (video_is_registered(vdev))
360 			ret = vdev->fops->unlocked_ioctl(filp, cmd, arg);
361 		if (lock)
362 			mutex_unlock(lock);
363 	} else
364 		ret = -ENOTTY;
365 
366 	return ret;
367 }
368 
369 #ifdef CONFIG_MMU
370 #define v4l2_get_unmapped_area NULL
371 #else
372 static unsigned long v4l2_get_unmapped_area(struct file *filp,
373 		unsigned long addr, unsigned long len, unsigned long pgoff,
374 		unsigned long flags)
375 {
376 	struct video_device *vdev = video_devdata(filp);
377 	int ret;
378 
379 	if (!vdev->fops->get_unmapped_area)
380 		return -ENOSYS;
381 	if (!video_is_registered(vdev))
382 		return -ENODEV;
383 	ret = vdev->fops->get_unmapped_area(filp, addr, len, pgoff, flags);
384 	if (vdev->dev_debug & V4L2_DEV_DEBUG_FOP)
385 		printk(KERN_DEBUG "%s: get_unmapped_area (%d)\n",
386 			video_device_node_name(vdev), ret);
387 	return ret;
388 }
389 #endif
390 
391 static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm)
392 {
393 	struct video_device *vdev = video_devdata(filp);
394 	int ret = -ENODEV;
395 
396 	if (!vdev->fops->mmap)
397 		return -ENODEV;
398 	if (video_is_registered(vdev))
399 		ret = vdev->fops->mmap(filp, vm);
400 	if (vdev->dev_debug & V4L2_DEV_DEBUG_FOP)
401 		printk(KERN_DEBUG "%s: mmap (%d)\n",
402 			video_device_node_name(vdev), ret);
403 	return ret;
404 }
405 
406 /* Override for the open function */
407 static int v4l2_open(struct inode *inode, struct file *filp)
408 {
409 	struct video_device *vdev;
410 	int ret = 0;
411 
412 	/* Check if the video device is available */
413 	mutex_lock(&videodev_lock);
414 	vdev = video_devdata(filp);
415 	/* return ENODEV if the video device has already been removed. */
416 	if (vdev == NULL || !video_is_registered(vdev)) {
417 		mutex_unlock(&videodev_lock);
418 		return -ENODEV;
419 	}
420 	/* and increase the device refcount */
421 	video_get(vdev);
422 	mutex_unlock(&videodev_lock);
423 	if (vdev->fops->open) {
424 		if (video_is_registered(vdev))
425 			ret = vdev->fops->open(filp);
426 		else
427 			ret = -ENODEV;
428 	}
429 
430 	if (vdev->dev_debug & V4L2_DEV_DEBUG_FOP)
431 		printk(KERN_DEBUG "%s: open (%d)\n",
432 			video_device_node_name(vdev), ret);
433 	/* decrease the refcount in case of an error */
434 	if (ret)
435 		video_put(vdev);
436 	return ret;
437 }
438 
439 /* Override for the release function */
440 static int v4l2_release(struct inode *inode, struct file *filp)
441 {
442 	struct video_device *vdev = video_devdata(filp);
443 	int ret = 0;
444 
445 	if (vdev->fops->release)
446 		ret = vdev->fops->release(filp);
447 	if (vdev->dev_debug & V4L2_DEV_DEBUG_FOP)
448 		printk(KERN_DEBUG "%s: release\n",
449 			video_device_node_name(vdev));
450 
451 	/* decrease the refcount unconditionally since the release()
452 	   return value is ignored. */
453 	video_put(vdev);
454 	return ret;
455 }
456 
457 static const struct file_operations v4l2_fops = {
458 	.owner = THIS_MODULE,
459 	.read = v4l2_read,
460 	.write = v4l2_write,
461 	.open = v4l2_open,
462 	.get_unmapped_area = v4l2_get_unmapped_area,
463 	.mmap = v4l2_mmap,
464 	.unlocked_ioctl = v4l2_ioctl,
465 #ifdef CONFIG_COMPAT
466 	.compat_ioctl = v4l2_compat_ioctl32,
467 #endif
468 	.release = v4l2_release,
469 	.poll = v4l2_poll,
470 	.llseek = no_llseek,
471 };
472 
473 /**
474  * get_index - assign stream index number based on v4l2_dev
475  * @vdev: video_device to assign index number to, vdev->v4l2_dev should be assigned
476  *
477  * Note that when this is called the new device has not yet been registered
478  * in the video_device array, but it was able to obtain a minor number.
479  *
480  * This means that we can always obtain a free stream index number since
481  * the worst case scenario is that there are VIDEO_NUM_DEVICES - 1 slots in
482  * use of the video_device array.
483  *
484  * Returns a free index number.
485  */
486 static int get_index(struct video_device *vdev)
487 {
488 	/* This can be static since this function is called with the global
489 	   videodev_lock held. */
490 	static DECLARE_BITMAP(used, VIDEO_NUM_DEVICES);
491 	int i;
492 
493 	bitmap_zero(used, VIDEO_NUM_DEVICES);
494 
495 	for (i = 0; i < VIDEO_NUM_DEVICES; i++) {
496 		if (video_device[i] != NULL &&
497 		    video_device[i]->v4l2_dev == vdev->v4l2_dev) {
498 			set_bit(video_device[i]->index, used);
499 		}
500 	}
501 
502 	return find_first_zero_bit(used, VIDEO_NUM_DEVICES);
503 }
504 
505 #define SET_VALID_IOCTL(ops, cmd, op)			\
506 	if (ops->op)					\
507 		set_bit(_IOC_NR(cmd), valid_ioctls)
508 
509 /* This determines which ioctls are actually implemented in the driver.
510    It's a one-time thing which simplifies video_ioctl2 as it can just do
511    a bit test.
512 
513    Note that drivers can override this by setting bits to 1 in
514    vdev->valid_ioctls. If an ioctl is marked as 1 when this function is
515    called, then that ioctl will actually be marked as unimplemented.
516 
517    It does that by first setting up the local valid_ioctls bitmap, and
518    at the end do a:
519 
520    vdev->valid_ioctls = valid_ioctls & ~(vdev->valid_ioctls)
521  */
522 static void determine_valid_ioctls(struct video_device *vdev)
523 {
524 	DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);
525 	const struct v4l2_ioctl_ops *ops = vdev->ioctl_ops;
526 	bool is_vid = vdev->vfl_type == VFL_TYPE_GRABBER;
527 	bool is_vbi = vdev->vfl_type == VFL_TYPE_VBI;
528 	bool is_radio = vdev->vfl_type == VFL_TYPE_RADIO;
529 	bool is_sdr = vdev->vfl_type == VFL_TYPE_SDR;
530 	bool is_tch = vdev->vfl_type == VFL_TYPE_TOUCH;
531 	bool is_rx = vdev->vfl_dir != VFL_DIR_TX;
532 	bool is_tx = vdev->vfl_dir != VFL_DIR_RX;
533 
534 	bitmap_zero(valid_ioctls, BASE_VIDIOC_PRIVATE);
535 
536 	/* vfl_type and vfl_dir independent ioctls */
537 
538 	SET_VALID_IOCTL(ops, VIDIOC_QUERYCAP, vidioc_querycap);
539 	set_bit(_IOC_NR(VIDIOC_G_PRIORITY), valid_ioctls);
540 	set_bit(_IOC_NR(VIDIOC_S_PRIORITY), valid_ioctls);
541 
542 	/* Note: the control handler can also be passed through the filehandle,
543 	   and that can't be tested here. If the bit for these control ioctls
544 	   is set, then the ioctl is valid. But if it is 0, then it can still
545 	   be valid if the filehandle passed the control handler. */
546 	if (vdev->ctrl_handler || ops->vidioc_queryctrl)
547 		set_bit(_IOC_NR(VIDIOC_QUERYCTRL), valid_ioctls);
548 	if (vdev->ctrl_handler || ops->vidioc_query_ext_ctrl)
549 		set_bit(_IOC_NR(VIDIOC_QUERY_EXT_CTRL), valid_ioctls);
550 	if (vdev->ctrl_handler || ops->vidioc_g_ctrl || ops->vidioc_g_ext_ctrls)
551 		set_bit(_IOC_NR(VIDIOC_G_CTRL), valid_ioctls);
552 	if (vdev->ctrl_handler || ops->vidioc_s_ctrl || ops->vidioc_s_ext_ctrls)
553 		set_bit(_IOC_NR(VIDIOC_S_CTRL), valid_ioctls);
554 	if (vdev->ctrl_handler || ops->vidioc_g_ext_ctrls)
555 		set_bit(_IOC_NR(VIDIOC_G_EXT_CTRLS), valid_ioctls);
556 	if (vdev->ctrl_handler || ops->vidioc_s_ext_ctrls)
557 		set_bit(_IOC_NR(VIDIOC_S_EXT_CTRLS), valid_ioctls);
558 	if (vdev->ctrl_handler || ops->vidioc_try_ext_ctrls)
559 		set_bit(_IOC_NR(VIDIOC_TRY_EXT_CTRLS), valid_ioctls);
560 	if (vdev->ctrl_handler || ops->vidioc_querymenu)
561 		set_bit(_IOC_NR(VIDIOC_QUERYMENU), valid_ioctls);
562 	SET_VALID_IOCTL(ops, VIDIOC_G_FREQUENCY, vidioc_g_frequency);
563 	SET_VALID_IOCTL(ops, VIDIOC_S_FREQUENCY, vidioc_s_frequency);
564 	SET_VALID_IOCTL(ops, VIDIOC_LOG_STATUS, vidioc_log_status);
565 #ifdef CONFIG_VIDEO_ADV_DEBUG
566 	set_bit(_IOC_NR(VIDIOC_DBG_G_CHIP_INFO), valid_ioctls);
567 	set_bit(_IOC_NR(VIDIOC_DBG_G_REGISTER), valid_ioctls);
568 	set_bit(_IOC_NR(VIDIOC_DBG_S_REGISTER), valid_ioctls);
569 #endif
570 	/* yes, really vidioc_subscribe_event */
571 	SET_VALID_IOCTL(ops, VIDIOC_DQEVENT, vidioc_subscribe_event);
572 	SET_VALID_IOCTL(ops, VIDIOC_SUBSCRIBE_EVENT, vidioc_subscribe_event);
573 	SET_VALID_IOCTL(ops, VIDIOC_UNSUBSCRIBE_EVENT, vidioc_unsubscribe_event);
574 	if (ops->vidioc_enum_freq_bands || ops->vidioc_g_tuner || ops->vidioc_g_modulator)
575 		set_bit(_IOC_NR(VIDIOC_ENUM_FREQ_BANDS), valid_ioctls);
576 
577 	if (is_vid || is_tch) {
578 		/* video and metadata specific ioctls */
579 		if ((is_rx && (ops->vidioc_enum_fmt_vid_cap ||
580 			       ops->vidioc_enum_fmt_vid_cap_mplane ||
581 			       ops->vidioc_enum_fmt_vid_overlay ||
582 			       ops->vidioc_enum_fmt_meta_cap)) ||
583 		    (is_tx && (ops->vidioc_enum_fmt_vid_out ||
584 			       ops->vidioc_enum_fmt_vid_out_mplane)))
585 			set_bit(_IOC_NR(VIDIOC_ENUM_FMT), valid_ioctls);
586 		if ((is_rx && (ops->vidioc_g_fmt_vid_cap ||
587 			       ops->vidioc_g_fmt_vid_cap_mplane ||
588 			       ops->vidioc_g_fmt_vid_overlay ||
589 			       ops->vidioc_g_fmt_meta_cap)) ||
590 		    (is_tx && (ops->vidioc_g_fmt_vid_out ||
591 			       ops->vidioc_g_fmt_vid_out_mplane ||
592 			       ops->vidioc_g_fmt_vid_out_overlay)))
593 			 set_bit(_IOC_NR(VIDIOC_G_FMT), valid_ioctls);
594 		if ((is_rx && (ops->vidioc_s_fmt_vid_cap ||
595 			       ops->vidioc_s_fmt_vid_cap_mplane ||
596 			       ops->vidioc_s_fmt_vid_overlay ||
597 			       ops->vidioc_s_fmt_meta_cap)) ||
598 		    (is_tx && (ops->vidioc_s_fmt_vid_out ||
599 			       ops->vidioc_s_fmt_vid_out_mplane ||
600 			       ops->vidioc_s_fmt_vid_out_overlay)))
601 			 set_bit(_IOC_NR(VIDIOC_S_FMT), valid_ioctls);
602 		if ((is_rx && (ops->vidioc_try_fmt_vid_cap ||
603 			       ops->vidioc_try_fmt_vid_cap_mplane ||
604 			       ops->vidioc_try_fmt_vid_overlay ||
605 			       ops->vidioc_try_fmt_meta_cap)) ||
606 		    (is_tx && (ops->vidioc_try_fmt_vid_out ||
607 			       ops->vidioc_try_fmt_vid_out_mplane ||
608 			       ops->vidioc_try_fmt_vid_out_overlay)))
609 			 set_bit(_IOC_NR(VIDIOC_TRY_FMT), valid_ioctls);
610 		SET_VALID_IOCTL(ops, VIDIOC_OVERLAY, vidioc_overlay);
611 		SET_VALID_IOCTL(ops, VIDIOC_G_FBUF, vidioc_g_fbuf);
612 		SET_VALID_IOCTL(ops, VIDIOC_S_FBUF, vidioc_s_fbuf);
613 		SET_VALID_IOCTL(ops, VIDIOC_G_JPEGCOMP, vidioc_g_jpegcomp);
614 		SET_VALID_IOCTL(ops, VIDIOC_S_JPEGCOMP, vidioc_s_jpegcomp);
615 		SET_VALID_IOCTL(ops, VIDIOC_G_ENC_INDEX, vidioc_g_enc_index);
616 		SET_VALID_IOCTL(ops, VIDIOC_ENCODER_CMD, vidioc_encoder_cmd);
617 		SET_VALID_IOCTL(ops, VIDIOC_TRY_ENCODER_CMD, vidioc_try_encoder_cmd);
618 		SET_VALID_IOCTL(ops, VIDIOC_DECODER_CMD, vidioc_decoder_cmd);
619 		SET_VALID_IOCTL(ops, VIDIOC_TRY_DECODER_CMD, vidioc_try_decoder_cmd);
620 		SET_VALID_IOCTL(ops, VIDIOC_ENUM_FRAMESIZES, vidioc_enum_framesizes);
621 		SET_VALID_IOCTL(ops, VIDIOC_ENUM_FRAMEINTERVALS, vidioc_enum_frameintervals);
622 		if (ops->vidioc_g_crop || ops->vidioc_g_selection)
623 			set_bit(_IOC_NR(VIDIOC_G_CROP), valid_ioctls);
624 		if (ops->vidioc_s_crop || ops->vidioc_s_selection)
625 			set_bit(_IOC_NR(VIDIOC_S_CROP), valid_ioctls);
626 		SET_VALID_IOCTL(ops, VIDIOC_G_SELECTION, vidioc_g_selection);
627 		SET_VALID_IOCTL(ops, VIDIOC_S_SELECTION, vidioc_s_selection);
628 		if (ops->vidioc_cropcap || ops->vidioc_g_selection)
629 			set_bit(_IOC_NR(VIDIOC_CROPCAP), valid_ioctls);
630 	} else if (is_vbi) {
631 		/* vbi specific ioctls */
632 		if ((is_rx && (ops->vidioc_g_fmt_vbi_cap ||
633 			       ops->vidioc_g_fmt_sliced_vbi_cap)) ||
634 		    (is_tx && (ops->vidioc_g_fmt_vbi_out ||
635 			       ops->vidioc_g_fmt_sliced_vbi_out)))
636 			set_bit(_IOC_NR(VIDIOC_G_FMT), valid_ioctls);
637 		if ((is_rx && (ops->vidioc_s_fmt_vbi_cap ||
638 			       ops->vidioc_s_fmt_sliced_vbi_cap)) ||
639 		    (is_tx && (ops->vidioc_s_fmt_vbi_out ||
640 			       ops->vidioc_s_fmt_sliced_vbi_out)))
641 			set_bit(_IOC_NR(VIDIOC_S_FMT), valid_ioctls);
642 		if ((is_rx && (ops->vidioc_try_fmt_vbi_cap ||
643 			       ops->vidioc_try_fmt_sliced_vbi_cap)) ||
644 		    (is_tx && (ops->vidioc_try_fmt_vbi_out ||
645 			       ops->vidioc_try_fmt_sliced_vbi_out)))
646 			set_bit(_IOC_NR(VIDIOC_TRY_FMT), valid_ioctls);
647 		SET_VALID_IOCTL(ops, VIDIOC_G_SLICED_VBI_CAP, vidioc_g_sliced_vbi_cap);
648 	} else if (is_sdr && is_rx) {
649 		/* SDR receiver specific ioctls */
650 		if (ops->vidioc_enum_fmt_sdr_cap)
651 			set_bit(_IOC_NR(VIDIOC_ENUM_FMT), valid_ioctls);
652 		if (ops->vidioc_g_fmt_sdr_cap)
653 			set_bit(_IOC_NR(VIDIOC_G_FMT), valid_ioctls);
654 		if (ops->vidioc_s_fmt_sdr_cap)
655 			set_bit(_IOC_NR(VIDIOC_S_FMT), valid_ioctls);
656 		if (ops->vidioc_try_fmt_sdr_cap)
657 			set_bit(_IOC_NR(VIDIOC_TRY_FMT), valid_ioctls);
658 	} else if (is_sdr && is_tx) {
659 		/* SDR transmitter specific ioctls */
660 		if (ops->vidioc_enum_fmt_sdr_out)
661 			set_bit(_IOC_NR(VIDIOC_ENUM_FMT), valid_ioctls);
662 		if (ops->vidioc_g_fmt_sdr_out)
663 			set_bit(_IOC_NR(VIDIOC_G_FMT), valid_ioctls);
664 		if (ops->vidioc_s_fmt_sdr_out)
665 			set_bit(_IOC_NR(VIDIOC_S_FMT), valid_ioctls);
666 		if (ops->vidioc_try_fmt_sdr_out)
667 			set_bit(_IOC_NR(VIDIOC_TRY_FMT), valid_ioctls);
668 	}
669 
670 	if (is_vid || is_vbi || is_sdr || is_tch) {
671 		/* ioctls valid for video, metadata, vbi or sdr */
672 		SET_VALID_IOCTL(ops, VIDIOC_REQBUFS, vidioc_reqbufs);
673 		SET_VALID_IOCTL(ops, VIDIOC_QUERYBUF, vidioc_querybuf);
674 		SET_VALID_IOCTL(ops, VIDIOC_QBUF, vidioc_qbuf);
675 		SET_VALID_IOCTL(ops, VIDIOC_EXPBUF, vidioc_expbuf);
676 		SET_VALID_IOCTL(ops, VIDIOC_DQBUF, vidioc_dqbuf);
677 		SET_VALID_IOCTL(ops, VIDIOC_CREATE_BUFS, vidioc_create_bufs);
678 		SET_VALID_IOCTL(ops, VIDIOC_PREPARE_BUF, vidioc_prepare_buf);
679 		SET_VALID_IOCTL(ops, VIDIOC_STREAMON, vidioc_streamon);
680 		SET_VALID_IOCTL(ops, VIDIOC_STREAMOFF, vidioc_streamoff);
681 	}
682 
683 	if (is_vid || is_vbi || is_tch) {
684 		/* ioctls valid for video or vbi */
685 		if (ops->vidioc_s_std)
686 			set_bit(_IOC_NR(VIDIOC_ENUMSTD), valid_ioctls);
687 		SET_VALID_IOCTL(ops, VIDIOC_S_STD, vidioc_s_std);
688 		SET_VALID_IOCTL(ops, VIDIOC_G_STD, vidioc_g_std);
689 		if (is_rx) {
690 			SET_VALID_IOCTL(ops, VIDIOC_QUERYSTD, vidioc_querystd);
691 			SET_VALID_IOCTL(ops, VIDIOC_ENUMINPUT, vidioc_enum_input);
692 			SET_VALID_IOCTL(ops, VIDIOC_G_INPUT, vidioc_g_input);
693 			SET_VALID_IOCTL(ops, VIDIOC_S_INPUT, vidioc_s_input);
694 			SET_VALID_IOCTL(ops, VIDIOC_ENUMAUDIO, vidioc_enumaudio);
695 			SET_VALID_IOCTL(ops, VIDIOC_G_AUDIO, vidioc_g_audio);
696 			SET_VALID_IOCTL(ops, VIDIOC_S_AUDIO, vidioc_s_audio);
697 			SET_VALID_IOCTL(ops, VIDIOC_QUERY_DV_TIMINGS, vidioc_query_dv_timings);
698 			SET_VALID_IOCTL(ops, VIDIOC_S_EDID, vidioc_s_edid);
699 		}
700 		if (is_tx) {
701 			SET_VALID_IOCTL(ops, VIDIOC_ENUMOUTPUT, vidioc_enum_output);
702 			SET_VALID_IOCTL(ops, VIDIOC_G_OUTPUT, vidioc_g_output);
703 			SET_VALID_IOCTL(ops, VIDIOC_S_OUTPUT, vidioc_s_output);
704 			SET_VALID_IOCTL(ops, VIDIOC_ENUMAUDOUT, vidioc_enumaudout);
705 			SET_VALID_IOCTL(ops, VIDIOC_G_AUDOUT, vidioc_g_audout);
706 			SET_VALID_IOCTL(ops, VIDIOC_S_AUDOUT, vidioc_s_audout);
707 		}
708 		if (ops->vidioc_g_parm || (vdev->vfl_type == VFL_TYPE_GRABBER &&
709 					ops->vidioc_g_std))
710 			set_bit(_IOC_NR(VIDIOC_G_PARM), valid_ioctls);
711 		SET_VALID_IOCTL(ops, VIDIOC_S_PARM, vidioc_s_parm);
712 		SET_VALID_IOCTL(ops, VIDIOC_S_DV_TIMINGS, vidioc_s_dv_timings);
713 		SET_VALID_IOCTL(ops, VIDIOC_G_DV_TIMINGS, vidioc_g_dv_timings);
714 		SET_VALID_IOCTL(ops, VIDIOC_ENUM_DV_TIMINGS, vidioc_enum_dv_timings);
715 		SET_VALID_IOCTL(ops, VIDIOC_DV_TIMINGS_CAP, vidioc_dv_timings_cap);
716 		SET_VALID_IOCTL(ops, VIDIOC_G_EDID, vidioc_g_edid);
717 	}
718 	if (is_tx && (is_radio || is_sdr)) {
719 		/* radio transmitter only ioctls */
720 		SET_VALID_IOCTL(ops, VIDIOC_G_MODULATOR, vidioc_g_modulator);
721 		SET_VALID_IOCTL(ops, VIDIOC_S_MODULATOR, vidioc_s_modulator);
722 	}
723 	if (is_rx) {
724 		/* receiver only ioctls */
725 		SET_VALID_IOCTL(ops, VIDIOC_G_TUNER, vidioc_g_tuner);
726 		SET_VALID_IOCTL(ops, VIDIOC_S_TUNER, vidioc_s_tuner);
727 		SET_VALID_IOCTL(ops, VIDIOC_S_HW_FREQ_SEEK, vidioc_s_hw_freq_seek);
728 	}
729 
730 	bitmap_andnot(vdev->valid_ioctls, valid_ioctls, vdev->valid_ioctls,
731 			BASE_VIDIOC_PRIVATE);
732 }
733 
734 static int video_register_media_controller(struct video_device *vdev, int type)
735 {
736 #if defined(CONFIG_MEDIA_CONTROLLER)
737 	u32 intf_type;
738 	int ret;
739 
740 	if (!vdev->v4l2_dev->mdev)
741 		return 0;
742 
743 	vdev->entity.obj_type = MEDIA_ENTITY_TYPE_VIDEO_DEVICE;
744 	vdev->entity.function = MEDIA_ENT_F_UNKNOWN;
745 
746 	switch (type) {
747 	case VFL_TYPE_GRABBER:
748 		intf_type = MEDIA_INTF_T_V4L_VIDEO;
749 		vdev->entity.function = MEDIA_ENT_F_IO_V4L;
750 		break;
751 	case VFL_TYPE_VBI:
752 		intf_type = MEDIA_INTF_T_V4L_VBI;
753 		vdev->entity.function = MEDIA_ENT_F_IO_VBI;
754 		break;
755 	case VFL_TYPE_SDR:
756 		intf_type = MEDIA_INTF_T_V4L_SWRADIO;
757 		vdev->entity.function = MEDIA_ENT_F_IO_SWRADIO;
758 		break;
759 	case VFL_TYPE_TOUCH:
760 		intf_type = MEDIA_INTF_T_V4L_TOUCH;
761 		vdev->entity.function = MEDIA_ENT_F_IO_V4L;
762 		break;
763 	case VFL_TYPE_RADIO:
764 		intf_type = MEDIA_INTF_T_V4L_RADIO;
765 		/*
766 		 * Radio doesn't have an entity at the V4L2 side to represent
767 		 * radio input or output. Instead, the audio input/output goes
768 		 * via either physical wires or ALSA.
769 		 */
770 		break;
771 	case VFL_TYPE_SUBDEV:
772 		intf_type = MEDIA_INTF_T_V4L_SUBDEV;
773 		/* Entity will be created via v4l2_device_register_subdev() */
774 		break;
775 	default:
776 		return 0;
777 	}
778 
779 	if (vdev->entity.function != MEDIA_ENT_F_UNKNOWN) {
780 		vdev->entity.name = vdev->name;
781 
782 		/* Needed just for backward compatibility with legacy MC API */
783 		vdev->entity.info.dev.major = VIDEO_MAJOR;
784 		vdev->entity.info.dev.minor = vdev->minor;
785 
786 		ret = media_device_register_entity(vdev->v4l2_dev->mdev,
787 						   &vdev->entity);
788 		if (ret < 0) {
789 			printk(KERN_WARNING
790 				"%s: media_device_register_entity failed\n",
791 				__func__);
792 			return ret;
793 		}
794 	}
795 
796 	vdev->intf_devnode = media_devnode_create(vdev->v4l2_dev->mdev,
797 						  intf_type,
798 						  0, VIDEO_MAJOR,
799 						  vdev->minor);
800 	if (!vdev->intf_devnode) {
801 		media_device_unregister_entity(&vdev->entity);
802 		return -ENOMEM;
803 	}
804 
805 	if (vdev->entity.function != MEDIA_ENT_F_UNKNOWN) {
806 		struct media_link *link;
807 
808 		link = media_create_intf_link(&vdev->entity,
809 					      &vdev->intf_devnode->intf,
810 					      MEDIA_LNK_FL_ENABLED);
811 		if (!link) {
812 			media_devnode_remove(vdev->intf_devnode);
813 			media_device_unregister_entity(&vdev->entity);
814 			return -ENOMEM;
815 		}
816 	}
817 
818 	/* FIXME: how to create the other interface links? */
819 
820 #endif
821 	return 0;
822 }
823 
824 int __video_register_device(struct video_device *vdev,
825 			    enum vfl_devnode_type type,
826 			    int nr, int warn_if_nr_in_use,
827 			    struct module *owner)
828 {
829 	int i = 0;
830 	int ret;
831 	int minor_offset = 0;
832 	int minor_cnt = VIDEO_NUM_DEVICES;
833 	const char *name_base;
834 
835 	/* A minor value of -1 marks this video device as never
836 	   having been registered */
837 	vdev->minor = -1;
838 
839 	/* the release callback MUST be present */
840 	if (WARN_ON(!vdev->release))
841 		return -EINVAL;
842 	/* the v4l2_dev pointer MUST be present */
843 	if (WARN_ON(!vdev->v4l2_dev))
844 		return -EINVAL;
845 
846 	/* v4l2_fh support */
847 	spin_lock_init(&vdev->fh_lock);
848 	INIT_LIST_HEAD(&vdev->fh_list);
849 
850 	/* Part 1: check device type */
851 	switch (type) {
852 	case VFL_TYPE_GRABBER:
853 		name_base = "video";
854 		break;
855 	case VFL_TYPE_VBI:
856 		name_base = "vbi";
857 		break;
858 	case VFL_TYPE_RADIO:
859 		name_base = "radio";
860 		break;
861 	case VFL_TYPE_SUBDEV:
862 		name_base = "v4l-subdev";
863 		break;
864 	case VFL_TYPE_SDR:
865 		/* Use device name 'swradio' because 'sdr' was already taken. */
866 		name_base = "swradio";
867 		break;
868 	case VFL_TYPE_TOUCH:
869 		name_base = "v4l-touch";
870 		break;
871 	default:
872 		printk(KERN_ERR "%s called with unknown type: %d\n",
873 		       __func__, type);
874 		return -EINVAL;
875 	}
876 
877 	vdev->vfl_type = type;
878 	vdev->cdev = NULL;
879 	if (vdev->dev_parent == NULL)
880 		vdev->dev_parent = vdev->v4l2_dev->dev;
881 	if (vdev->ctrl_handler == NULL)
882 		vdev->ctrl_handler = vdev->v4l2_dev->ctrl_handler;
883 	/* If the prio state pointer is NULL, then use the v4l2_device
884 	   prio state. */
885 	if (vdev->prio == NULL)
886 		vdev->prio = &vdev->v4l2_dev->prio;
887 
888 	/* Part 2: find a free minor, device node number and device index. */
889 #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
890 	/* Keep the ranges for the first four types for historical
891 	 * reasons.
892 	 * Newer devices (not yet in place) should use the range
893 	 * of 128-191 and just pick the first free minor there
894 	 * (new style). */
895 	switch (type) {
896 	case VFL_TYPE_GRABBER:
897 		minor_offset = 0;
898 		minor_cnt = 64;
899 		break;
900 	case VFL_TYPE_RADIO:
901 		minor_offset = 64;
902 		minor_cnt = 64;
903 		break;
904 	case VFL_TYPE_VBI:
905 		minor_offset = 224;
906 		minor_cnt = 32;
907 		break;
908 	default:
909 		minor_offset = 128;
910 		minor_cnt = 64;
911 		break;
912 	}
913 #endif
914 
915 	/* Pick a device node number */
916 	mutex_lock(&videodev_lock);
917 	nr = devnode_find(vdev, nr == -1 ? 0 : nr, minor_cnt);
918 	if (nr == minor_cnt)
919 		nr = devnode_find(vdev, 0, minor_cnt);
920 	if (nr == minor_cnt) {
921 		printk(KERN_ERR "could not get a free device node number\n");
922 		mutex_unlock(&videodev_lock);
923 		return -ENFILE;
924 	}
925 #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
926 	/* 1-on-1 mapping of device node number to minor number */
927 	i = nr;
928 #else
929 	/* The device node number and minor numbers are independent, so
930 	   we just find the first free minor number. */
931 	for (i = 0; i < VIDEO_NUM_DEVICES; i++)
932 		if (video_device[i] == NULL)
933 			break;
934 	if (i == VIDEO_NUM_DEVICES) {
935 		mutex_unlock(&videodev_lock);
936 		printk(KERN_ERR "could not get a free minor\n");
937 		return -ENFILE;
938 	}
939 #endif
940 	vdev->minor = i + minor_offset;
941 	vdev->num = nr;
942 
943 	/* Should not happen since we thought this minor was free */
944 	if (WARN_ON(video_device[vdev->minor])) {
945 		mutex_unlock(&videodev_lock);
946 		printk(KERN_ERR "video_device not empty!\n");
947 		return -ENFILE;
948 	}
949 	devnode_set(vdev);
950 	vdev->index = get_index(vdev);
951 	video_device[vdev->minor] = vdev;
952 	mutex_unlock(&videodev_lock);
953 
954 	if (vdev->ioctl_ops)
955 		determine_valid_ioctls(vdev);
956 
957 	/* Part 3: Initialize the character device */
958 	vdev->cdev = cdev_alloc();
959 	if (vdev->cdev == NULL) {
960 		ret = -ENOMEM;
961 		goto cleanup;
962 	}
963 	vdev->cdev->ops = &v4l2_fops;
964 	vdev->cdev->owner = owner;
965 	ret = cdev_add(vdev->cdev, MKDEV(VIDEO_MAJOR, vdev->minor), 1);
966 	if (ret < 0) {
967 		printk(KERN_ERR "%s: cdev_add failed\n", __func__);
968 		kfree(vdev->cdev);
969 		vdev->cdev = NULL;
970 		goto cleanup;
971 	}
972 
973 	/* Part 4: register the device with sysfs */
974 	vdev->dev.class = &video_class;
975 	vdev->dev.devt = MKDEV(VIDEO_MAJOR, vdev->minor);
976 	vdev->dev.parent = vdev->dev_parent;
977 	dev_set_name(&vdev->dev, "%s%d", name_base, vdev->num);
978 	ret = device_register(&vdev->dev);
979 	if (ret < 0) {
980 		printk(KERN_ERR "%s: device_register failed\n", __func__);
981 		goto cleanup;
982 	}
983 	/* Register the release callback that will be called when the last
984 	   reference to the device goes away. */
985 	vdev->dev.release = v4l2_device_release;
986 
987 	if (nr != -1 && nr != vdev->num && warn_if_nr_in_use)
988 		printk(KERN_WARNING "%s: requested %s%d, got %s\n", __func__,
989 			name_base, nr, video_device_node_name(vdev));
990 
991 	/* Increase v4l2_device refcount */
992 	v4l2_device_get(vdev->v4l2_dev);
993 
994 	/* Part 5: Register the entity. */
995 	ret = video_register_media_controller(vdev, type);
996 
997 	/* Part 6: Activate this minor. The char device can now be used. */
998 	set_bit(V4L2_FL_REGISTERED, &vdev->flags);
999 
1000 	return 0;
1001 
1002 cleanup:
1003 	mutex_lock(&videodev_lock);
1004 	if (vdev->cdev)
1005 		cdev_del(vdev->cdev);
1006 	video_device[vdev->minor] = NULL;
1007 	devnode_clear(vdev);
1008 	mutex_unlock(&videodev_lock);
1009 	/* Mark this video device as never having been registered. */
1010 	vdev->minor = -1;
1011 	return ret;
1012 }
1013 EXPORT_SYMBOL(__video_register_device);
1014 
1015 /**
1016  *	video_unregister_device - unregister a video4linux device
1017  *	@vdev: the device to unregister
1018  *
1019  *	This unregisters the passed device. Future open calls will
1020  *	be met with errors.
1021  */
1022 void video_unregister_device(struct video_device *vdev)
1023 {
1024 	/* Check if vdev was ever registered at all */
1025 	if (!vdev || !video_is_registered(vdev))
1026 		return;
1027 
1028 	mutex_lock(&videodev_lock);
1029 	/* This must be in a critical section to prevent a race with v4l2_open.
1030 	 * Once this bit has been cleared video_get may never be called again.
1031 	 */
1032 	clear_bit(V4L2_FL_REGISTERED, &vdev->flags);
1033 	mutex_unlock(&videodev_lock);
1034 	device_unregister(&vdev->dev);
1035 }
1036 EXPORT_SYMBOL(video_unregister_device);
1037 
1038 /*
1039  *	Initialise video for linux
1040  */
1041 static int __init videodev_init(void)
1042 {
1043 	dev_t dev = MKDEV(VIDEO_MAJOR, 0);
1044 	int ret;
1045 
1046 	printk(KERN_INFO "Linux video capture interface: v2.00\n");
1047 	ret = register_chrdev_region(dev, VIDEO_NUM_DEVICES, VIDEO_NAME);
1048 	if (ret < 0) {
1049 		printk(KERN_WARNING "videodev: unable to get major %d\n",
1050 				VIDEO_MAJOR);
1051 		return ret;
1052 	}
1053 
1054 	ret = class_register(&video_class);
1055 	if (ret < 0) {
1056 		unregister_chrdev_region(dev, VIDEO_NUM_DEVICES);
1057 		printk(KERN_WARNING "video_dev: class_register failed\n");
1058 		return -EIO;
1059 	}
1060 
1061 	return 0;
1062 }
1063 
1064 static void __exit videodev_exit(void)
1065 {
1066 	dev_t dev = MKDEV(VIDEO_MAJOR, 0);
1067 
1068 	class_unregister(&video_class);
1069 	unregister_chrdev_region(dev, VIDEO_NUM_DEVICES);
1070 }
1071 
1072 subsys_initcall(videodev_init);
1073 module_exit(videodev_exit)
1074 
1075 MODULE_AUTHOR("Alan Cox, Mauro Carvalho Chehab <mchehab@infradead.org>");
1076 MODULE_DESCRIPTION("Device registrar for Video4Linux drivers v2");
1077 MODULE_LICENSE("GPL");
1078 MODULE_ALIAS_CHARDEV_MAJOR(VIDEO_MAJOR);
1079