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 <asm/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 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->debug);
56 }
57 
58 static ssize_t 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->debug = value;
70 	return len;
71 }
72 static DEVICE_ATTR_RW(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_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(int 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(int 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 && v4l2_dev->mdev &&
198 	    vdev->vfl_type != VFL_TYPE_SUBDEV)
199 		media_device_unregister_entity(&vdev->entity);
200 #endif
201 
202 	/* Do not call v4l2_device_put if there is no release callback set.
203 	 * Drivers that have no v4l2_device release callback might free the
204 	 * v4l2_dev instance in the video_device release callback below, so we
205 	 * must perform this check here.
206 	 *
207 	 * TODO: In the long run all drivers that use v4l2_device should use the
208 	 * v4l2_device release callback. This check will then be unnecessary.
209 	 */
210 	if (v4l2_dev && v4l2_dev->release == NULL)
211 		v4l2_dev = NULL;
212 
213 	/* Release video_device and perform other
214 	   cleanups as needed. */
215 	vdev->release(vdev);
216 
217 	/* Decrease v4l2_device refcount */
218 	if (v4l2_dev)
219 		v4l2_device_put(v4l2_dev);
220 }
221 
222 static struct class video_class = {
223 	.name = VIDEO_NAME,
224 	.dev_groups = video_device_groups,
225 };
226 
227 struct video_device *video_devdata(struct file *file)
228 {
229 	return video_device[iminor(file_inode(file))];
230 }
231 EXPORT_SYMBOL(video_devdata);
232 
233 
234 /* Priority handling */
235 
236 static inline bool prio_is_valid(enum v4l2_priority prio)
237 {
238 	return prio == V4L2_PRIORITY_BACKGROUND ||
239 	       prio == V4L2_PRIORITY_INTERACTIVE ||
240 	       prio == V4L2_PRIORITY_RECORD;
241 }
242 
243 void v4l2_prio_init(struct v4l2_prio_state *global)
244 {
245 	memset(global, 0, sizeof(*global));
246 }
247 EXPORT_SYMBOL(v4l2_prio_init);
248 
249 int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
250 		     enum v4l2_priority new)
251 {
252 	if (!prio_is_valid(new))
253 		return -EINVAL;
254 	if (*local == new)
255 		return 0;
256 
257 	atomic_inc(&global->prios[new]);
258 	if (prio_is_valid(*local))
259 		atomic_dec(&global->prios[*local]);
260 	*local = new;
261 	return 0;
262 }
263 EXPORT_SYMBOL(v4l2_prio_change);
264 
265 void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local)
266 {
267 	v4l2_prio_change(global, local, V4L2_PRIORITY_DEFAULT);
268 }
269 EXPORT_SYMBOL(v4l2_prio_open);
270 
271 void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local)
272 {
273 	if (prio_is_valid(local))
274 		atomic_dec(&global->prios[local]);
275 }
276 EXPORT_SYMBOL(v4l2_prio_close);
277 
278 enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global)
279 {
280 	if (atomic_read(&global->prios[V4L2_PRIORITY_RECORD]) > 0)
281 		return V4L2_PRIORITY_RECORD;
282 	if (atomic_read(&global->prios[V4L2_PRIORITY_INTERACTIVE]) > 0)
283 		return V4L2_PRIORITY_INTERACTIVE;
284 	if (atomic_read(&global->prios[V4L2_PRIORITY_BACKGROUND]) > 0)
285 		return V4L2_PRIORITY_BACKGROUND;
286 	return V4L2_PRIORITY_UNSET;
287 }
288 EXPORT_SYMBOL(v4l2_prio_max);
289 
290 int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local)
291 {
292 	return (local < v4l2_prio_max(global)) ? -EBUSY : 0;
293 }
294 EXPORT_SYMBOL(v4l2_prio_check);
295 
296 
297 static ssize_t v4l2_read(struct file *filp, char __user *buf,
298 		size_t sz, loff_t *off)
299 {
300 	struct video_device *vdev = video_devdata(filp);
301 	int ret = -ENODEV;
302 
303 	if (!vdev->fops->read)
304 		return -EINVAL;
305 	if (video_is_registered(vdev))
306 		ret = vdev->fops->read(filp, buf, sz, off);
307 	if (vdev->debug)
308 		printk(KERN_DEBUG "%s: read: %zd (%d)\n",
309 			video_device_node_name(vdev), sz, ret);
310 	return ret;
311 }
312 
313 static ssize_t v4l2_write(struct file *filp, const char __user *buf,
314 		size_t sz, loff_t *off)
315 {
316 	struct video_device *vdev = video_devdata(filp);
317 	int ret = -ENODEV;
318 
319 	if (!vdev->fops->write)
320 		return -EINVAL;
321 	if (video_is_registered(vdev))
322 		ret = vdev->fops->write(filp, buf, sz, off);
323 	if (vdev->debug)
324 		printk(KERN_DEBUG "%s: write: %zd (%d)\n",
325 			video_device_node_name(vdev), sz, ret);
326 	return ret;
327 }
328 
329 static unsigned int v4l2_poll(struct file *filp, struct poll_table_struct *poll)
330 {
331 	struct video_device *vdev = video_devdata(filp);
332 	unsigned int res = POLLERR | POLLHUP;
333 
334 	if (!vdev->fops->poll)
335 		return DEFAULT_POLLMASK;
336 	if (video_is_registered(vdev))
337 		res = vdev->fops->poll(filp, poll);
338 	if (vdev->debug)
339 		printk(KERN_DEBUG "%s: poll: %08x\n",
340 			video_device_node_name(vdev), res);
341 	return res;
342 }
343 
344 static long v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
345 {
346 	struct video_device *vdev = video_devdata(filp);
347 	int ret = -ENODEV;
348 
349 	if (vdev->fops->unlocked_ioctl) {
350 		struct mutex *lock = v4l2_ioctl_get_lock(vdev, cmd);
351 
352 		if (lock && mutex_lock_interruptible(lock))
353 			return -ERESTARTSYS;
354 		if (video_is_registered(vdev))
355 			ret = vdev->fops->unlocked_ioctl(filp, cmd, arg);
356 		if (lock)
357 			mutex_unlock(lock);
358 	} else if (vdev->fops->ioctl) {
359 		/* This code path is a replacement for the BKL. It is a major
360 		 * hack but it will have to do for those drivers that are not
361 		 * yet converted to use unlocked_ioctl.
362 		 *
363 		 * There are two options: if the driver implements struct
364 		 * v4l2_device, then the lock defined there is used to
365 		 * serialize the ioctls. Otherwise the v4l2 core lock defined
366 		 * below is used. This lock is really bad since it serializes
367 		 * completely independent devices.
368 		 *
369 		 * Both variants suffer from the same problem: if the driver
370 		 * sleeps, then it blocks all ioctls since the lock is still
371 		 * held. This is very common for VIDIOC_DQBUF since that
372 		 * normally waits for a frame to arrive. As a result any other
373 		 * ioctl calls will proceed very, very slowly since each call
374 		 * will have to wait for the VIDIOC_QBUF to finish. Things that
375 		 * should take 0.01s may now take 10-20 seconds.
376 		 *
377 		 * The workaround is to *not* take the lock for VIDIOC_DQBUF.
378 		 * This actually works OK for videobuf-based drivers, since
379 		 * videobuf will take its own internal lock.
380 		 */
381 		static DEFINE_MUTEX(v4l2_ioctl_mutex);
382 		struct mutex *m = vdev->v4l2_dev ?
383 			&vdev->v4l2_dev->ioctl_lock : &v4l2_ioctl_mutex;
384 
385 		if (cmd != VIDIOC_DQBUF && mutex_lock_interruptible(m))
386 			return -ERESTARTSYS;
387 		if (video_is_registered(vdev))
388 			ret = vdev->fops->ioctl(filp, cmd, arg);
389 		if (cmd != VIDIOC_DQBUF)
390 			mutex_unlock(m);
391 	} else
392 		ret = -ENOTTY;
393 
394 	return ret;
395 }
396 
397 #ifdef CONFIG_MMU
398 #define v4l2_get_unmapped_area NULL
399 #else
400 static unsigned long v4l2_get_unmapped_area(struct file *filp,
401 		unsigned long addr, unsigned long len, unsigned long pgoff,
402 		unsigned long flags)
403 {
404 	struct video_device *vdev = video_devdata(filp);
405 	int ret;
406 
407 	if (!vdev->fops->get_unmapped_area)
408 		return -ENOSYS;
409 	if (!video_is_registered(vdev))
410 		return -ENODEV;
411 	ret = vdev->fops->get_unmapped_area(filp, addr, len, pgoff, flags);
412 	if (vdev->debug)
413 		printk(KERN_DEBUG "%s: get_unmapped_area (%d)\n",
414 			video_device_node_name(vdev), ret);
415 	return ret;
416 }
417 #endif
418 
419 static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm)
420 {
421 	struct video_device *vdev = video_devdata(filp);
422 	int ret = -ENODEV;
423 
424 	if (!vdev->fops->mmap)
425 		return -ENODEV;
426 	if (video_is_registered(vdev))
427 		ret = vdev->fops->mmap(filp, vm);
428 	if (vdev->debug)
429 		printk(KERN_DEBUG "%s: mmap (%d)\n",
430 			video_device_node_name(vdev), ret);
431 	return ret;
432 }
433 
434 /* Override for the open function */
435 static int v4l2_open(struct inode *inode, struct file *filp)
436 {
437 	struct video_device *vdev;
438 	int ret = 0;
439 
440 	/* Check if the video device is available */
441 	mutex_lock(&videodev_lock);
442 	vdev = video_devdata(filp);
443 	/* return ENODEV if the video device has already been removed. */
444 	if (vdev == NULL || !video_is_registered(vdev)) {
445 		mutex_unlock(&videodev_lock);
446 		return -ENODEV;
447 	}
448 	/* and increase the device refcount */
449 	video_get(vdev);
450 	mutex_unlock(&videodev_lock);
451 	if (vdev->fops->open) {
452 		if (video_is_registered(vdev))
453 			ret = vdev->fops->open(filp);
454 		else
455 			ret = -ENODEV;
456 	}
457 
458 	if (vdev->debug)
459 		printk(KERN_DEBUG "%s: open (%d)\n",
460 			video_device_node_name(vdev), ret);
461 	/* decrease the refcount in case of an error */
462 	if (ret)
463 		video_put(vdev);
464 	return ret;
465 }
466 
467 /* Override for the release function */
468 static int v4l2_release(struct inode *inode, struct file *filp)
469 {
470 	struct video_device *vdev = video_devdata(filp);
471 	int ret = 0;
472 
473 	if (vdev->fops->release)
474 		ret = vdev->fops->release(filp);
475 	if (vdev->debug)
476 		printk(KERN_DEBUG "%s: release\n",
477 			video_device_node_name(vdev));
478 
479 	/* decrease the refcount unconditionally since the release()
480 	   return value is ignored. */
481 	video_put(vdev);
482 	return ret;
483 }
484 
485 static const struct file_operations v4l2_fops = {
486 	.owner = THIS_MODULE,
487 	.read = v4l2_read,
488 	.write = v4l2_write,
489 	.open = v4l2_open,
490 	.get_unmapped_area = v4l2_get_unmapped_area,
491 	.mmap = v4l2_mmap,
492 	.unlocked_ioctl = v4l2_ioctl,
493 #ifdef CONFIG_COMPAT
494 	.compat_ioctl = v4l2_compat_ioctl32,
495 #endif
496 	.release = v4l2_release,
497 	.poll = v4l2_poll,
498 	.llseek = no_llseek,
499 };
500 
501 /**
502  * get_index - assign stream index number based on v4l2_dev
503  * @vdev: video_device to assign index number to, vdev->v4l2_dev should be assigned
504  *
505  * Note that when this is called the new device has not yet been registered
506  * in the video_device array, but it was able to obtain a minor number.
507  *
508  * This means that we can always obtain a free stream index number since
509  * the worst case scenario is that there are VIDEO_NUM_DEVICES - 1 slots in
510  * use of the video_device array.
511  *
512  * Returns a free index number.
513  */
514 static int get_index(struct video_device *vdev)
515 {
516 	/* This can be static since this function is called with the global
517 	   videodev_lock held. */
518 	static DECLARE_BITMAP(used, VIDEO_NUM_DEVICES);
519 	int i;
520 
521 	bitmap_zero(used, VIDEO_NUM_DEVICES);
522 
523 	for (i = 0; i < VIDEO_NUM_DEVICES; i++) {
524 		if (video_device[i] != NULL &&
525 		    video_device[i]->v4l2_dev == vdev->v4l2_dev) {
526 			set_bit(video_device[i]->index, used);
527 		}
528 	}
529 
530 	return find_first_zero_bit(used, VIDEO_NUM_DEVICES);
531 }
532 
533 #define SET_VALID_IOCTL(ops, cmd, op)			\
534 	if (ops->op)					\
535 		set_bit(_IOC_NR(cmd), valid_ioctls)
536 
537 /* This determines which ioctls are actually implemented in the driver.
538    It's a one-time thing which simplifies video_ioctl2 as it can just do
539    a bit test.
540 
541    Note that drivers can override this by setting bits to 1 in
542    vdev->valid_ioctls. If an ioctl is marked as 1 when this function is
543    called, then that ioctl will actually be marked as unimplemented.
544 
545    It does that by first setting up the local valid_ioctls bitmap, and
546    at the end do a:
547 
548    vdev->valid_ioctls = valid_ioctls & ~(vdev->valid_ioctls)
549  */
550 static void determine_valid_ioctls(struct video_device *vdev)
551 {
552 	DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);
553 	const struct v4l2_ioctl_ops *ops = vdev->ioctl_ops;
554 	bool is_vid = vdev->vfl_type == VFL_TYPE_GRABBER;
555 	bool is_vbi = vdev->vfl_type == VFL_TYPE_VBI;
556 	bool is_radio = vdev->vfl_type == VFL_TYPE_RADIO;
557 	bool is_rx = vdev->vfl_dir != VFL_DIR_TX;
558 	bool is_tx = vdev->vfl_dir != VFL_DIR_RX;
559 
560 	bitmap_zero(valid_ioctls, BASE_VIDIOC_PRIVATE);
561 
562 	/* vfl_type and vfl_dir independent ioctls */
563 
564 	SET_VALID_IOCTL(ops, VIDIOC_QUERYCAP, vidioc_querycap);
565 	if (ops->vidioc_g_priority ||
566 			test_bit(V4L2_FL_USE_FH_PRIO, &vdev->flags))
567 		set_bit(_IOC_NR(VIDIOC_G_PRIORITY), valid_ioctls);
568 	if (ops->vidioc_s_priority ||
569 			test_bit(V4L2_FL_USE_FH_PRIO, &vdev->flags))
570 		set_bit(_IOC_NR(VIDIOC_S_PRIORITY), valid_ioctls);
571 	SET_VALID_IOCTL(ops, VIDIOC_STREAMON, vidioc_streamon);
572 	SET_VALID_IOCTL(ops, VIDIOC_STREAMOFF, vidioc_streamoff);
573 	/* Note: the control handler can also be passed through the filehandle,
574 	   and that can't be tested here. If the bit for these control ioctls
575 	   is set, then the ioctl is valid. But if it is 0, then it can still
576 	   be valid if the filehandle passed the control handler. */
577 	if (vdev->ctrl_handler || ops->vidioc_queryctrl)
578 		set_bit(_IOC_NR(VIDIOC_QUERYCTRL), valid_ioctls);
579 	if (vdev->ctrl_handler || ops->vidioc_g_ctrl || ops->vidioc_g_ext_ctrls)
580 		set_bit(_IOC_NR(VIDIOC_G_CTRL), valid_ioctls);
581 	if (vdev->ctrl_handler || ops->vidioc_s_ctrl || ops->vidioc_s_ext_ctrls)
582 		set_bit(_IOC_NR(VIDIOC_S_CTRL), valid_ioctls);
583 	if (vdev->ctrl_handler || ops->vidioc_g_ext_ctrls)
584 		set_bit(_IOC_NR(VIDIOC_G_EXT_CTRLS), valid_ioctls);
585 	if (vdev->ctrl_handler || ops->vidioc_s_ext_ctrls)
586 		set_bit(_IOC_NR(VIDIOC_S_EXT_CTRLS), valid_ioctls);
587 	if (vdev->ctrl_handler || ops->vidioc_try_ext_ctrls)
588 		set_bit(_IOC_NR(VIDIOC_TRY_EXT_CTRLS), valid_ioctls);
589 	if (vdev->ctrl_handler || ops->vidioc_querymenu)
590 		set_bit(_IOC_NR(VIDIOC_QUERYMENU), valid_ioctls);
591 	SET_VALID_IOCTL(ops, VIDIOC_G_FREQUENCY, vidioc_g_frequency);
592 	SET_VALID_IOCTL(ops, VIDIOC_S_FREQUENCY, vidioc_s_frequency);
593 	SET_VALID_IOCTL(ops, VIDIOC_LOG_STATUS, vidioc_log_status);
594 #ifdef CONFIG_VIDEO_ADV_DEBUG
595 	set_bit(_IOC_NR(VIDIOC_DBG_G_CHIP_INFO), valid_ioctls);
596 	set_bit(_IOC_NR(VIDIOC_DBG_G_REGISTER), valid_ioctls);
597 	set_bit(_IOC_NR(VIDIOC_DBG_S_REGISTER), valid_ioctls);
598 #endif
599 	/* yes, really vidioc_subscribe_event */
600 	SET_VALID_IOCTL(ops, VIDIOC_DQEVENT, vidioc_subscribe_event);
601 	SET_VALID_IOCTL(ops, VIDIOC_SUBSCRIBE_EVENT, vidioc_subscribe_event);
602 	SET_VALID_IOCTL(ops, VIDIOC_UNSUBSCRIBE_EVENT, vidioc_unsubscribe_event);
603 	if (ops->vidioc_enum_freq_bands || ops->vidioc_g_tuner || ops->vidioc_g_modulator)
604 		set_bit(_IOC_NR(VIDIOC_ENUM_FREQ_BANDS), valid_ioctls);
605 
606 	if (is_vid) {
607 		/* video specific ioctls */
608 		if ((is_rx && (ops->vidioc_enum_fmt_vid_cap ||
609 			       ops->vidioc_enum_fmt_vid_cap_mplane ||
610 			       ops->vidioc_enum_fmt_vid_overlay)) ||
611 		    (is_tx && (ops->vidioc_enum_fmt_vid_out ||
612 			       ops->vidioc_enum_fmt_vid_out_mplane)))
613 			set_bit(_IOC_NR(VIDIOC_ENUM_FMT), valid_ioctls);
614 		if ((is_rx && (ops->vidioc_g_fmt_vid_cap ||
615 			       ops->vidioc_g_fmt_vid_cap_mplane ||
616 			       ops->vidioc_g_fmt_vid_overlay)) ||
617 		    (is_tx && (ops->vidioc_g_fmt_vid_out ||
618 			       ops->vidioc_g_fmt_vid_out_mplane ||
619 			       ops->vidioc_g_fmt_vid_out_overlay)))
620 			 set_bit(_IOC_NR(VIDIOC_G_FMT), valid_ioctls);
621 		if ((is_rx && (ops->vidioc_s_fmt_vid_cap ||
622 			       ops->vidioc_s_fmt_vid_cap_mplane ||
623 			       ops->vidioc_s_fmt_vid_overlay)) ||
624 		    (is_tx && (ops->vidioc_s_fmt_vid_out ||
625 			       ops->vidioc_s_fmt_vid_out_mplane ||
626 			       ops->vidioc_s_fmt_vid_out_overlay)))
627 			 set_bit(_IOC_NR(VIDIOC_S_FMT), valid_ioctls);
628 		if ((is_rx && (ops->vidioc_try_fmt_vid_cap ||
629 			       ops->vidioc_try_fmt_vid_cap_mplane ||
630 			       ops->vidioc_try_fmt_vid_overlay)) ||
631 		    (is_tx && (ops->vidioc_try_fmt_vid_out ||
632 			       ops->vidioc_try_fmt_vid_out_mplane ||
633 			       ops->vidioc_try_fmt_vid_out_overlay)))
634 			 set_bit(_IOC_NR(VIDIOC_TRY_FMT), valid_ioctls);
635 		SET_VALID_IOCTL(ops, VIDIOC_OVERLAY, vidioc_overlay);
636 		SET_VALID_IOCTL(ops, VIDIOC_G_FBUF, vidioc_g_fbuf);
637 		SET_VALID_IOCTL(ops, VIDIOC_S_FBUF, vidioc_s_fbuf);
638 		SET_VALID_IOCTL(ops, VIDIOC_G_JPEGCOMP, vidioc_g_jpegcomp);
639 		SET_VALID_IOCTL(ops, VIDIOC_S_JPEGCOMP, vidioc_s_jpegcomp);
640 		SET_VALID_IOCTL(ops, VIDIOC_G_ENC_INDEX, vidioc_g_enc_index);
641 		SET_VALID_IOCTL(ops, VIDIOC_ENCODER_CMD, vidioc_encoder_cmd);
642 		SET_VALID_IOCTL(ops, VIDIOC_TRY_ENCODER_CMD, vidioc_try_encoder_cmd);
643 		SET_VALID_IOCTL(ops, VIDIOC_DECODER_CMD, vidioc_decoder_cmd);
644 		SET_VALID_IOCTL(ops, VIDIOC_TRY_DECODER_CMD, vidioc_try_decoder_cmd);
645 		SET_VALID_IOCTL(ops, VIDIOC_ENUM_FRAMESIZES, vidioc_enum_framesizes);
646 		SET_VALID_IOCTL(ops, VIDIOC_ENUM_FRAMEINTERVALS, vidioc_enum_frameintervals);
647 	} else if (is_vbi) {
648 		/* vbi specific ioctls */
649 		if ((is_rx && (ops->vidioc_g_fmt_vbi_cap ||
650 			       ops->vidioc_g_fmt_sliced_vbi_cap)) ||
651 		    (is_tx && (ops->vidioc_g_fmt_vbi_out ||
652 			       ops->vidioc_g_fmt_sliced_vbi_out)))
653 			set_bit(_IOC_NR(VIDIOC_G_FMT), valid_ioctls);
654 		if ((is_rx && (ops->vidioc_s_fmt_vbi_cap ||
655 			       ops->vidioc_s_fmt_sliced_vbi_cap)) ||
656 		    (is_tx && (ops->vidioc_s_fmt_vbi_out ||
657 			       ops->vidioc_s_fmt_sliced_vbi_out)))
658 			set_bit(_IOC_NR(VIDIOC_S_FMT), valid_ioctls);
659 		if ((is_rx && (ops->vidioc_try_fmt_vbi_cap ||
660 			       ops->vidioc_try_fmt_sliced_vbi_cap)) ||
661 		    (is_tx && (ops->vidioc_try_fmt_vbi_out ||
662 			       ops->vidioc_try_fmt_sliced_vbi_out)))
663 			set_bit(_IOC_NR(VIDIOC_TRY_FMT), valid_ioctls);
664 		SET_VALID_IOCTL(ops, VIDIOC_G_SLICED_VBI_CAP, vidioc_g_sliced_vbi_cap);
665 	}
666 	if (!is_radio) {
667 		/* ioctls valid for video or vbi */
668 		SET_VALID_IOCTL(ops, VIDIOC_REQBUFS, vidioc_reqbufs);
669 		SET_VALID_IOCTL(ops, VIDIOC_QUERYBUF, vidioc_querybuf);
670 		SET_VALID_IOCTL(ops, VIDIOC_QBUF, vidioc_qbuf);
671 		SET_VALID_IOCTL(ops, VIDIOC_EXPBUF, vidioc_expbuf);
672 		SET_VALID_IOCTL(ops, VIDIOC_DQBUF, vidioc_dqbuf);
673 		SET_VALID_IOCTL(ops, VIDIOC_CREATE_BUFS, vidioc_create_bufs);
674 		SET_VALID_IOCTL(ops, VIDIOC_PREPARE_BUF, vidioc_prepare_buf);
675 		if (ops->vidioc_s_std)
676 			set_bit(_IOC_NR(VIDIOC_ENUMSTD), valid_ioctls);
677 		SET_VALID_IOCTL(ops, VIDIOC_S_STD, vidioc_s_std);
678 		SET_VALID_IOCTL(ops, VIDIOC_G_STD, vidioc_g_std);
679 		if (is_rx) {
680 			SET_VALID_IOCTL(ops, VIDIOC_QUERYSTD, vidioc_querystd);
681 			SET_VALID_IOCTL(ops, VIDIOC_ENUMINPUT, vidioc_enum_input);
682 			SET_VALID_IOCTL(ops, VIDIOC_G_INPUT, vidioc_g_input);
683 			SET_VALID_IOCTL(ops, VIDIOC_S_INPUT, vidioc_s_input);
684 			SET_VALID_IOCTL(ops, VIDIOC_ENUMAUDIO, vidioc_enumaudio);
685 			SET_VALID_IOCTL(ops, VIDIOC_G_AUDIO, vidioc_g_audio);
686 			SET_VALID_IOCTL(ops, VIDIOC_S_AUDIO, vidioc_s_audio);
687 			SET_VALID_IOCTL(ops, VIDIOC_QUERY_DV_TIMINGS, vidioc_query_dv_timings);
688 		}
689 		if (is_tx) {
690 			SET_VALID_IOCTL(ops, VIDIOC_ENUMOUTPUT, vidioc_enum_output);
691 			SET_VALID_IOCTL(ops, VIDIOC_G_OUTPUT, vidioc_g_output);
692 			SET_VALID_IOCTL(ops, VIDIOC_S_OUTPUT, vidioc_s_output);
693 			SET_VALID_IOCTL(ops, VIDIOC_ENUMAUDOUT, vidioc_enumaudout);
694 			SET_VALID_IOCTL(ops, VIDIOC_G_AUDOUT, vidioc_g_audout);
695 			SET_VALID_IOCTL(ops, VIDIOC_S_AUDOUT, vidioc_s_audout);
696 		}
697 		if (ops->vidioc_g_crop || ops->vidioc_g_selection)
698 			set_bit(_IOC_NR(VIDIOC_G_CROP), valid_ioctls);
699 		if (ops->vidioc_s_crop || ops->vidioc_s_selection)
700 			set_bit(_IOC_NR(VIDIOC_S_CROP), valid_ioctls);
701 		SET_VALID_IOCTL(ops, VIDIOC_G_SELECTION, vidioc_g_selection);
702 		SET_VALID_IOCTL(ops, VIDIOC_S_SELECTION, vidioc_s_selection);
703 		if (ops->vidioc_cropcap || ops->vidioc_g_selection)
704 			set_bit(_IOC_NR(VIDIOC_CROPCAP), valid_ioctls);
705 		if (ops->vidioc_g_parm || (vdev->vfl_type == VFL_TYPE_GRABBER &&
706 					ops->vidioc_g_std))
707 			set_bit(_IOC_NR(VIDIOC_G_PARM), valid_ioctls);
708 		SET_VALID_IOCTL(ops, VIDIOC_S_PARM, vidioc_s_parm);
709 		SET_VALID_IOCTL(ops, VIDIOC_S_DV_TIMINGS, vidioc_s_dv_timings);
710 		SET_VALID_IOCTL(ops, VIDIOC_G_DV_TIMINGS, vidioc_g_dv_timings);
711 		SET_VALID_IOCTL(ops, VIDIOC_ENUM_DV_TIMINGS, vidioc_enum_dv_timings);
712 		SET_VALID_IOCTL(ops, VIDIOC_DV_TIMINGS_CAP, vidioc_dv_timings_cap);
713 	}
714 	if (is_tx) {
715 		/* transmitter only ioctls */
716 		SET_VALID_IOCTL(ops, VIDIOC_G_MODULATOR, vidioc_g_modulator);
717 		SET_VALID_IOCTL(ops, VIDIOC_S_MODULATOR, vidioc_s_modulator);
718 	}
719 	if (is_rx) {
720 		/* receiver only ioctls */
721 		SET_VALID_IOCTL(ops, VIDIOC_G_TUNER, vidioc_g_tuner);
722 		SET_VALID_IOCTL(ops, VIDIOC_S_TUNER, vidioc_s_tuner);
723 		SET_VALID_IOCTL(ops, VIDIOC_S_HW_FREQ_SEEK, vidioc_s_hw_freq_seek);
724 	}
725 
726 	bitmap_andnot(vdev->valid_ioctls, valid_ioctls, vdev->valid_ioctls,
727 			BASE_VIDIOC_PRIVATE);
728 }
729 
730 /**
731  *	__video_register_device - register video4linux devices
732  *	@vdev: video device structure we want to register
733  *	@type: type of device to register
734  *	@nr:   which device node number (0 == /dev/video0, 1 == /dev/video1, ...
735  *             -1 == first free)
736  *	@warn_if_nr_in_use: warn if the desired device node number
737  *	       was already in use and another number was chosen instead.
738  *	@owner: module that owns the video device node
739  *
740  *	The registration code assigns minor numbers and device node numbers
741  *	based on the requested type and registers the new device node with
742  *	the kernel.
743  *
744  *	This function assumes that struct video_device was zeroed when it
745  *	was allocated and does not contain any stale date.
746  *
747  *	An error is returned if no free minor or device node number could be
748  *	found, or if the registration of the device node failed.
749  *
750  *	Zero is returned on success.
751  *
752  *	Valid types are
753  *
754  *	%VFL_TYPE_GRABBER - A frame grabber
755  *
756  *	%VFL_TYPE_VBI - Vertical blank data (undecoded)
757  *
758  *	%VFL_TYPE_RADIO - A radio card
759  *
760  *	%VFL_TYPE_SUBDEV - A subdevice
761  */
762 int __video_register_device(struct video_device *vdev, int type, int nr,
763 		int warn_if_nr_in_use, struct module *owner)
764 {
765 	int i = 0;
766 	int ret;
767 	int minor_offset = 0;
768 	int minor_cnt = VIDEO_NUM_DEVICES;
769 	const char *name_base;
770 
771 	/* A minor value of -1 marks this video device as never
772 	   having been registered */
773 	vdev->minor = -1;
774 
775 	/* the release callback MUST be present */
776 	if (WARN_ON(!vdev->release))
777 		return -EINVAL;
778 	/* the v4l2_dev pointer MUST be present */
779 	if (WARN_ON(!vdev->v4l2_dev))
780 		return -EINVAL;
781 
782 	/* v4l2_fh support */
783 	spin_lock_init(&vdev->fh_lock);
784 	INIT_LIST_HEAD(&vdev->fh_list);
785 
786 	/* Part 1: check device type */
787 	switch (type) {
788 	case VFL_TYPE_GRABBER:
789 		name_base = "video";
790 		break;
791 	case VFL_TYPE_VBI:
792 		name_base = "vbi";
793 		break;
794 	case VFL_TYPE_RADIO:
795 		name_base = "radio";
796 		break;
797 	case VFL_TYPE_SUBDEV:
798 		name_base = "v4l-subdev";
799 		break;
800 	default:
801 		printk(KERN_ERR "%s called with unknown type: %d\n",
802 		       __func__, type);
803 		return -EINVAL;
804 	}
805 
806 	vdev->vfl_type = type;
807 	vdev->cdev = NULL;
808 	if (vdev->dev_parent == NULL)
809 		vdev->dev_parent = vdev->v4l2_dev->dev;
810 	if (vdev->ctrl_handler == NULL)
811 		vdev->ctrl_handler = vdev->v4l2_dev->ctrl_handler;
812 	/* If the prio state pointer is NULL, then use the v4l2_device
813 	   prio state. */
814 	if (vdev->prio == NULL)
815 		vdev->prio = &vdev->v4l2_dev->prio;
816 
817 	/* Part 2: find a free minor, device node number and device index. */
818 #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
819 	/* Keep the ranges for the first four types for historical
820 	 * reasons.
821 	 * Newer devices (not yet in place) should use the range
822 	 * of 128-191 and just pick the first free minor there
823 	 * (new style). */
824 	switch (type) {
825 	case VFL_TYPE_GRABBER:
826 		minor_offset = 0;
827 		minor_cnt = 64;
828 		break;
829 	case VFL_TYPE_RADIO:
830 		minor_offset = 64;
831 		minor_cnt = 64;
832 		break;
833 	case VFL_TYPE_VBI:
834 		minor_offset = 224;
835 		minor_cnt = 32;
836 		break;
837 	default:
838 		minor_offset = 128;
839 		minor_cnt = 64;
840 		break;
841 	}
842 #endif
843 
844 	/* Pick a device node number */
845 	mutex_lock(&videodev_lock);
846 	nr = devnode_find(vdev, nr == -1 ? 0 : nr, minor_cnt);
847 	if (nr == minor_cnt)
848 		nr = devnode_find(vdev, 0, minor_cnt);
849 	if (nr == minor_cnt) {
850 		printk(KERN_ERR "could not get a free device node number\n");
851 		mutex_unlock(&videodev_lock);
852 		return -ENFILE;
853 	}
854 #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
855 	/* 1-on-1 mapping of device node number to minor number */
856 	i = nr;
857 #else
858 	/* The device node number and minor numbers are independent, so
859 	   we just find the first free minor number. */
860 	for (i = 0; i < VIDEO_NUM_DEVICES; i++)
861 		if (video_device[i] == NULL)
862 			break;
863 	if (i == VIDEO_NUM_DEVICES) {
864 		mutex_unlock(&videodev_lock);
865 		printk(KERN_ERR "could not get a free minor\n");
866 		return -ENFILE;
867 	}
868 #endif
869 	vdev->minor = i + minor_offset;
870 	vdev->num = nr;
871 	devnode_set(vdev);
872 
873 	/* Should not happen since we thought this minor was free */
874 	WARN_ON(video_device[vdev->minor] != NULL);
875 	video_device[vdev->minor] = vdev;
876 	vdev->index = get_index(vdev);
877 	mutex_unlock(&videodev_lock);
878 
879 	if (vdev->ioctl_ops)
880 		determine_valid_ioctls(vdev);
881 
882 	/* Part 3: Initialize the character device */
883 	vdev->cdev = cdev_alloc();
884 	if (vdev->cdev == NULL) {
885 		ret = -ENOMEM;
886 		goto cleanup;
887 	}
888 	vdev->cdev->ops = &v4l2_fops;
889 	vdev->cdev->owner = owner;
890 	ret = cdev_add(vdev->cdev, MKDEV(VIDEO_MAJOR, vdev->minor), 1);
891 	if (ret < 0) {
892 		printk(KERN_ERR "%s: cdev_add failed\n", __func__);
893 		kfree(vdev->cdev);
894 		vdev->cdev = NULL;
895 		goto cleanup;
896 	}
897 
898 	/* Part 4: register the device with sysfs */
899 	vdev->dev.class = &video_class;
900 	vdev->dev.devt = MKDEV(VIDEO_MAJOR, vdev->minor);
901 	vdev->dev.parent = vdev->dev_parent;
902 	dev_set_name(&vdev->dev, "%s%d", name_base, vdev->num);
903 	ret = device_register(&vdev->dev);
904 	if (ret < 0) {
905 		printk(KERN_ERR "%s: device_register failed\n", __func__);
906 		goto cleanup;
907 	}
908 	/* Register the release callback that will be called when the last
909 	   reference to the device goes away. */
910 	vdev->dev.release = v4l2_device_release;
911 
912 	if (nr != -1 && nr != vdev->num && warn_if_nr_in_use)
913 		printk(KERN_WARNING "%s: requested %s%d, got %s\n", __func__,
914 			name_base, nr, video_device_node_name(vdev));
915 
916 	/* Increase v4l2_device refcount */
917 	if (vdev->v4l2_dev)
918 		v4l2_device_get(vdev->v4l2_dev);
919 
920 #if defined(CONFIG_MEDIA_CONTROLLER)
921 	/* Part 5: Register the entity. */
922 	if (vdev->v4l2_dev && vdev->v4l2_dev->mdev &&
923 	    vdev->vfl_type != VFL_TYPE_SUBDEV) {
924 		vdev->entity.type = MEDIA_ENT_T_DEVNODE_V4L;
925 		vdev->entity.name = vdev->name;
926 		vdev->entity.info.v4l.major = VIDEO_MAJOR;
927 		vdev->entity.info.v4l.minor = vdev->minor;
928 		ret = media_device_register_entity(vdev->v4l2_dev->mdev,
929 			&vdev->entity);
930 		if (ret < 0)
931 			printk(KERN_WARNING
932 			       "%s: media_device_register_entity failed\n",
933 			       __func__);
934 	}
935 #endif
936 	/* Part 6: Activate this minor. The char device can now be used. */
937 	set_bit(V4L2_FL_REGISTERED, &vdev->flags);
938 
939 	return 0;
940 
941 cleanup:
942 	mutex_lock(&videodev_lock);
943 	if (vdev->cdev)
944 		cdev_del(vdev->cdev);
945 	video_device[vdev->minor] = NULL;
946 	devnode_clear(vdev);
947 	mutex_unlock(&videodev_lock);
948 	/* Mark this video device as never having been registered. */
949 	vdev->minor = -1;
950 	return ret;
951 }
952 EXPORT_SYMBOL(__video_register_device);
953 
954 /**
955  *	video_unregister_device - unregister a video4linux device
956  *	@vdev: the device to unregister
957  *
958  *	This unregisters the passed device. Future open calls will
959  *	be met with errors.
960  */
961 void video_unregister_device(struct video_device *vdev)
962 {
963 	/* Check if vdev was ever registered at all */
964 	if (!vdev || !video_is_registered(vdev))
965 		return;
966 
967 	mutex_lock(&videodev_lock);
968 	/* This must be in a critical section to prevent a race with v4l2_open.
969 	 * Once this bit has been cleared video_get may never be called again.
970 	 */
971 	clear_bit(V4L2_FL_REGISTERED, &vdev->flags);
972 	mutex_unlock(&videodev_lock);
973 	device_unregister(&vdev->dev);
974 }
975 EXPORT_SYMBOL(video_unregister_device);
976 
977 /*
978  *	Initialise video for linux
979  */
980 static int __init videodev_init(void)
981 {
982 	dev_t dev = MKDEV(VIDEO_MAJOR, 0);
983 	int ret;
984 
985 	printk(KERN_INFO "Linux video capture interface: v2.00\n");
986 	ret = register_chrdev_region(dev, VIDEO_NUM_DEVICES, VIDEO_NAME);
987 	if (ret < 0) {
988 		printk(KERN_WARNING "videodev: unable to get major %d\n",
989 				VIDEO_MAJOR);
990 		return ret;
991 	}
992 
993 	ret = class_register(&video_class);
994 	if (ret < 0) {
995 		unregister_chrdev_region(dev, VIDEO_NUM_DEVICES);
996 		printk(KERN_WARNING "video_dev: class_register failed\n");
997 		return -EIO;
998 	}
999 
1000 	return 0;
1001 }
1002 
1003 static void __exit videodev_exit(void)
1004 {
1005 	dev_t dev = MKDEV(VIDEO_MAJOR, 0);
1006 
1007 	class_unregister(&video_class);
1008 	unregister_chrdev_region(dev, VIDEO_NUM_DEVICES);
1009 }
1010 
1011 subsys_initcall(videodev_init);
1012 module_exit(videodev_exit)
1013 
1014 MODULE_AUTHOR("Alan Cox, Mauro Carvalho Chehab <mchehab@infradead.org>");
1015 MODULE_DESCRIPTION("Device registrar for Video4Linux drivers v2");
1016 MODULE_LICENSE("GPL");
1017 MODULE_ALIAS_CHARDEV_MAJOR(VIDEO_MAJOR);
1018 
1019 
1020 /*
1021  * Local variables:
1022  * c-basic-offset: 8
1023  * End:
1024  */
1025