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 show_index(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 
49 static ssize_t show_debug(struct device *cd,
50 			 struct device_attribute *attr, char *buf)
51 {
52 	struct video_device *vdev = to_video_device(cd);
53 
54 	return sprintf(buf, "%i\n", vdev->debug);
55 }
56 
57 static ssize_t set_debug(struct device *cd, struct device_attribute *attr,
58 		   const char *buf, size_t len)
59 {
60 	struct video_device *vdev = to_video_device(cd);
61 	int res = 0;
62 	u16 value;
63 
64 	res = kstrtou16(buf, 0, &value);
65 	if (res)
66 		return res;
67 
68 	vdev->debug = value;
69 	return len;
70 }
71 
72 static ssize_t show_name(struct device *cd,
73 			 struct device_attribute *attr, char *buf)
74 {
75 	struct video_device *vdev = to_video_device(cd);
76 
77 	return sprintf(buf, "%.*s\n", (int)sizeof(vdev->name), vdev->name);
78 }
79 
80 static struct device_attribute video_device_attrs[] = {
81 	__ATTR(name, S_IRUGO, show_name, NULL),
82 	__ATTR(debug, 0644, show_debug, set_debug),
83 	__ATTR(index, S_IRUGO, show_index, NULL),
84 	__ATTR_NULL
85 };
86 
87 /*
88  *	Active devices
89  */
90 static struct video_device *video_device[VIDEO_NUM_DEVICES];
91 static DEFINE_MUTEX(videodev_lock);
92 static DECLARE_BITMAP(devnode_nums[VFL_TYPE_MAX], VIDEO_NUM_DEVICES);
93 
94 /* Device node utility functions */
95 
96 /* Note: these utility functions all assume that vfl_type is in the range
97    [0, VFL_TYPE_MAX-1]. */
98 
99 #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
100 /* Return the bitmap corresponding to vfl_type. */
101 static inline unsigned long *devnode_bits(int vfl_type)
102 {
103 	/* Any types not assigned to fixed minor ranges must be mapped to
104 	   one single bitmap for the purposes of finding a free node number
105 	   since all those unassigned types use the same minor range. */
106 	int idx = (vfl_type > VFL_TYPE_RADIO) ? VFL_TYPE_MAX - 1 : vfl_type;
107 
108 	return devnode_nums[idx];
109 }
110 #else
111 /* Return the bitmap corresponding to vfl_type. */
112 static inline unsigned long *devnode_bits(int vfl_type)
113 {
114 	return devnode_nums[vfl_type];
115 }
116 #endif
117 
118 /* Mark device node number vdev->num as used */
119 static inline void devnode_set(struct video_device *vdev)
120 {
121 	set_bit(vdev->num, devnode_bits(vdev->vfl_type));
122 }
123 
124 /* Mark device node number vdev->num as unused */
125 static inline void devnode_clear(struct video_device *vdev)
126 {
127 	clear_bit(vdev->num, devnode_bits(vdev->vfl_type));
128 }
129 
130 /* Try to find a free device node number in the range [from, to> */
131 static inline int devnode_find(struct video_device *vdev, int from, int to)
132 {
133 	return find_next_zero_bit(devnode_bits(vdev->vfl_type), to, from);
134 }
135 
136 struct video_device *video_device_alloc(void)
137 {
138 	return kzalloc(sizeof(struct video_device), GFP_KERNEL);
139 }
140 EXPORT_SYMBOL(video_device_alloc);
141 
142 void video_device_release(struct video_device *vdev)
143 {
144 	kfree(vdev);
145 }
146 EXPORT_SYMBOL(video_device_release);
147 
148 void video_device_release_empty(struct video_device *vdev)
149 {
150 	/* Do nothing */
151 	/* Only valid when the video_device struct is a static. */
152 }
153 EXPORT_SYMBOL(video_device_release_empty);
154 
155 static inline void video_get(struct video_device *vdev)
156 {
157 	get_device(&vdev->dev);
158 }
159 
160 static inline void video_put(struct video_device *vdev)
161 {
162 	put_device(&vdev->dev);
163 }
164 
165 /* Called when the last user of the video device exits. */
166 static void v4l2_device_release(struct device *cd)
167 {
168 	struct video_device *vdev = to_video_device(cd);
169 	struct v4l2_device *v4l2_dev = vdev->v4l2_dev;
170 
171 	mutex_lock(&videodev_lock);
172 	if (WARN_ON(video_device[vdev->minor] != vdev)) {
173 		/* should not happen */
174 		mutex_unlock(&videodev_lock);
175 		return;
176 	}
177 
178 	/* Free up this device for reuse */
179 	video_device[vdev->minor] = NULL;
180 
181 	/* Delete the cdev on this minor as well */
182 	cdev_del(vdev->cdev);
183 	/* Just in case some driver tries to access this from
184 	   the release() callback. */
185 	vdev->cdev = NULL;
186 
187 	/* Mark device node number as free */
188 	devnode_clear(vdev);
189 
190 	mutex_unlock(&videodev_lock);
191 
192 #if defined(CONFIG_MEDIA_CONTROLLER)
193 	if (v4l2_dev && v4l2_dev->mdev &&
194 	    vdev->vfl_type != VFL_TYPE_SUBDEV)
195 		media_device_unregister_entity(&vdev->entity);
196 #endif
197 
198 	/* Do not call v4l2_device_put if there is no release callback set.
199 	 * Drivers that have no v4l2_device release callback might free the
200 	 * v4l2_dev instance in the video_device release callback below, so we
201 	 * must perform this check here.
202 	 *
203 	 * TODO: In the long run all drivers that use v4l2_device should use the
204 	 * v4l2_device release callback. This check will then be unnecessary.
205 	 */
206 	if (v4l2_dev && v4l2_dev->release == NULL)
207 		v4l2_dev = NULL;
208 
209 	/* Release video_device and perform other
210 	   cleanups as needed. */
211 	vdev->release(vdev);
212 
213 	/* Decrease v4l2_device refcount */
214 	if (v4l2_dev)
215 		v4l2_device_put(v4l2_dev);
216 }
217 
218 static struct class video_class = {
219 	.name = VIDEO_NAME,
220 	.dev_attrs = video_device_attrs,
221 };
222 
223 struct video_device *video_devdata(struct file *file)
224 {
225 	return video_device[iminor(file_inode(file))];
226 }
227 EXPORT_SYMBOL(video_devdata);
228 
229 
230 /* Priority handling */
231 
232 static inline bool prio_is_valid(enum v4l2_priority prio)
233 {
234 	return prio == V4L2_PRIORITY_BACKGROUND ||
235 	       prio == V4L2_PRIORITY_INTERACTIVE ||
236 	       prio == V4L2_PRIORITY_RECORD;
237 }
238 
239 void v4l2_prio_init(struct v4l2_prio_state *global)
240 {
241 	memset(global, 0, sizeof(*global));
242 }
243 EXPORT_SYMBOL(v4l2_prio_init);
244 
245 int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
246 		     enum v4l2_priority new)
247 {
248 	if (!prio_is_valid(new))
249 		return -EINVAL;
250 	if (*local == new)
251 		return 0;
252 
253 	atomic_inc(&global->prios[new]);
254 	if (prio_is_valid(*local))
255 		atomic_dec(&global->prios[*local]);
256 	*local = new;
257 	return 0;
258 }
259 EXPORT_SYMBOL(v4l2_prio_change);
260 
261 void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local)
262 {
263 	v4l2_prio_change(global, local, V4L2_PRIORITY_DEFAULT);
264 }
265 EXPORT_SYMBOL(v4l2_prio_open);
266 
267 void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local)
268 {
269 	if (prio_is_valid(local))
270 		atomic_dec(&global->prios[local]);
271 }
272 EXPORT_SYMBOL(v4l2_prio_close);
273 
274 enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global)
275 {
276 	if (atomic_read(&global->prios[V4L2_PRIORITY_RECORD]) > 0)
277 		return V4L2_PRIORITY_RECORD;
278 	if (atomic_read(&global->prios[V4L2_PRIORITY_INTERACTIVE]) > 0)
279 		return V4L2_PRIORITY_INTERACTIVE;
280 	if (atomic_read(&global->prios[V4L2_PRIORITY_BACKGROUND]) > 0)
281 		return V4L2_PRIORITY_BACKGROUND;
282 	return V4L2_PRIORITY_UNSET;
283 }
284 EXPORT_SYMBOL(v4l2_prio_max);
285 
286 int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local)
287 {
288 	return (local < v4l2_prio_max(global)) ? -EBUSY : 0;
289 }
290 EXPORT_SYMBOL(v4l2_prio_check);
291 
292 
293 static ssize_t v4l2_read(struct file *filp, char __user *buf,
294 		size_t sz, loff_t *off)
295 {
296 	struct video_device *vdev = video_devdata(filp);
297 	int ret = -ENODEV;
298 
299 	if (!vdev->fops->read)
300 		return -EINVAL;
301 	if (video_is_registered(vdev))
302 		ret = vdev->fops->read(filp, buf, sz, off);
303 	if (vdev->debug)
304 		printk(KERN_DEBUG "%s: read: %zd (%d)\n",
305 			video_device_node_name(vdev), sz, ret);
306 	return ret;
307 }
308 
309 static ssize_t v4l2_write(struct file *filp, const char __user *buf,
310 		size_t sz, loff_t *off)
311 {
312 	struct video_device *vdev = video_devdata(filp);
313 	int ret = -ENODEV;
314 
315 	if (!vdev->fops->write)
316 		return -EINVAL;
317 	if (video_is_registered(vdev))
318 		ret = vdev->fops->write(filp, buf, sz, off);
319 	if (vdev->debug)
320 		printk(KERN_DEBUG "%s: write: %zd (%d)\n",
321 			video_device_node_name(vdev), sz, ret);
322 	return ret;
323 }
324 
325 static unsigned int v4l2_poll(struct file *filp, struct poll_table_struct *poll)
326 {
327 	struct video_device *vdev = video_devdata(filp);
328 	unsigned int res = POLLERR | POLLHUP;
329 
330 	if (!vdev->fops->poll)
331 		return DEFAULT_POLLMASK;
332 	if (video_is_registered(vdev))
333 		res = vdev->fops->poll(filp, poll);
334 	if (vdev->debug)
335 		printk(KERN_DEBUG "%s: poll: %08x\n",
336 			video_device_node_name(vdev), res);
337 	return res;
338 }
339 
340 static long v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
341 {
342 	struct video_device *vdev = video_devdata(filp);
343 	int ret = -ENODEV;
344 
345 	if (vdev->fops->unlocked_ioctl) {
346 		struct mutex *lock = v4l2_ioctl_get_lock(vdev, cmd);
347 
348 		if (lock && mutex_lock_interruptible(lock))
349 			return -ERESTARTSYS;
350 		if (video_is_registered(vdev))
351 			ret = vdev->fops->unlocked_ioctl(filp, cmd, arg);
352 		if (lock)
353 			mutex_unlock(lock);
354 	} else if (vdev->fops->ioctl) {
355 		/* This code path is a replacement for the BKL. It is a major
356 		 * hack but it will have to do for those drivers that are not
357 		 * yet converted to use unlocked_ioctl.
358 		 *
359 		 * There are two options: if the driver implements struct
360 		 * v4l2_device, then the lock defined there is used to
361 		 * serialize the ioctls. Otherwise the v4l2 core lock defined
362 		 * below is used. This lock is really bad since it serializes
363 		 * completely independent devices.
364 		 *
365 		 * Both variants suffer from the same problem: if the driver
366 		 * sleeps, then it blocks all ioctls since the lock is still
367 		 * held. This is very common for VIDIOC_DQBUF since that
368 		 * normally waits for a frame to arrive. As a result any other
369 		 * ioctl calls will proceed very, very slowly since each call
370 		 * will have to wait for the VIDIOC_QBUF to finish. Things that
371 		 * should take 0.01s may now take 10-20 seconds.
372 		 *
373 		 * The workaround is to *not* take the lock for VIDIOC_DQBUF.
374 		 * This actually works OK for videobuf-based drivers, since
375 		 * videobuf will take its own internal lock.
376 		 */
377 		static DEFINE_MUTEX(v4l2_ioctl_mutex);
378 		struct mutex *m = vdev->v4l2_dev ?
379 			&vdev->v4l2_dev->ioctl_lock : &v4l2_ioctl_mutex;
380 
381 		if (cmd != VIDIOC_DQBUF && mutex_lock_interruptible(m))
382 			return -ERESTARTSYS;
383 		if (video_is_registered(vdev))
384 			ret = vdev->fops->ioctl(filp, cmd, arg);
385 		if (cmd != VIDIOC_DQBUF)
386 			mutex_unlock(m);
387 	} else
388 		ret = -ENOTTY;
389 
390 	return ret;
391 }
392 
393 #ifdef CONFIG_MMU
394 #define v4l2_get_unmapped_area NULL
395 #else
396 static unsigned long v4l2_get_unmapped_area(struct file *filp,
397 		unsigned long addr, unsigned long len, unsigned long pgoff,
398 		unsigned long flags)
399 {
400 	struct video_device *vdev = video_devdata(filp);
401 	int ret;
402 
403 	if (!vdev->fops->get_unmapped_area)
404 		return -ENOSYS;
405 	if (!video_is_registered(vdev))
406 		return -ENODEV;
407 	ret = vdev->fops->get_unmapped_area(filp, addr, len, pgoff, flags);
408 	if (vdev->debug)
409 		printk(KERN_DEBUG "%s: get_unmapped_area (%d)\n",
410 			video_device_node_name(vdev), ret);
411 	return ret;
412 }
413 #endif
414 
415 static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm)
416 {
417 	struct video_device *vdev = video_devdata(filp);
418 	int ret = -ENODEV;
419 
420 	if (!vdev->fops->mmap)
421 		return -ENODEV;
422 	if (video_is_registered(vdev))
423 		ret = vdev->fops->mmap(filp, vm);
424 	if (vdev->debug)
425 		printk(KERN_DEBUG "%s: mmap (%d)\n",
426 			video_device_node_name(vdev), ret);
427 	return ret;
428 }
429 
430 /* Override for the open function */
431 static int v4l2_open(struct inode *inode, struct file *filp)
432 {
433 	struct video_device *vdev;
434 	int ret = 0;
435 
436 	/* Check if the video device is available */
437 	mutex_lock(&videodev_lock);
438 	vdev = video_devdata(filp);
439 	/* return ENODEV if the video device has already been removed. */
440 	if (vdev == NULL || !video_is_registered(vdev)) {
441 		mutex_unlock(&videodev_lock);
442 		return -ENODEV;
443 	}
444 	/* and increase the device refcount */
445 	video_get(vdev);
446 	mutex_unlock(&videodev_lock);
447 	if (vdev->fops->open) {
448 		if (video_is_registered(vdev))
449 			ret = vdev->fops->open(filp);
450 		else
451 			ret = -ENODEV;
452 	}
453 
454 	if (vdev->debug)
455 		printk(KERN_DEBUG "%s: open (%d)\n",
456 			video_device_node_name(vdev), ret);
457 	/* decrease the refcount in case of an error */
458 	if (ret)
459 		video_put(vdev);
460 	return ret;
461 }
462 
463 /* Override for the release function */
464 static int v4l2_release(struct inode *inode, struct file *filp)
465 {
466 	struct video_device *vdev = video_devdata(filp);
467 	int ret = 0;
468 
469 	if (vdev->fops->release)
470 		ret = vdev->fops->release(filp);
471 	if (vdev->debug)
472 		printk(KERN_DEBUG "%s: release\n",
473 			video_device_node_name(vdev));
474 
475 	/* decrease the refcount unconditionally since the release()
476 	   return value is ignored. */
477 	video_put(vdev);
478 	return ret;
479 }
480 
481 static const struct file_operations v4l2_fops = {
482 	.owner = THIS_MODULE,
483 	.read = v4l2_read,
484 	.write = v4l2_write,
485 	.open = v4l2_open,
486 	.get_unmapped_area = v4l2_get_unmapped_area,
487 	.mmap = v4l2_mmap,
488 	.unlocked_ioctl = v4l2_ioctl,
489 #ifdef CONFIG_COMPAT
490 	.compat_ioctl = v4l2_compat_ioctl32,
491 #endif
492 	.release = v4l2_release,
493 	.poll = v4l2_poll,
494 	.llseek = no_llseek,
495 };
496 
497 /**
498  * get_index - assign stream index number based on v4l2_dev
499  * @vdev: video_device to assign index number to, vdev->v4l2_dev should be assigned
500  *
501  * Note that when this is called the new device has not yet been registered
502  * in the video_device array, but it was able to obtain a minor number.
503  *
504  * This means that we can always obtain a free stream index number since
505  * the worst case scenario is that there are VIDEO_NUM_DEVICES - 1 slots in
506  * use of the video_device array.
507  *
508  * Returns a free index number.
509  */
510 static int get_index(struct video_device *vdev)
511 {
512 	/* This can be static since this function is called with the global
513 	   videodev_lock held. */
514 	static DECLARE_BITMAP(used, VIDEO_NUM_DEVICES);
515 	int i;
516 
517 	bitmap_zero(used, VIDEO_NUM_DEVICES);
518 
519 	for (i = 0; i < VIDEO_NUM_DEVICES; i++) {
520 		if (video_device[i] != NULL &&
521 		    video_device[i]->v4l2_dev == vdev->v4l2_dev) {
522 			set_bit(video_device[i]->index, used);
523 		}
524 	}
525 
526 	return find_first_zero_bit(used, VIDEO_NUM_DEVICES);
527 }
528 
529 #define SET_VALID_IOCTL(ops, cmd, op)			\
530 	if (ops->op)					\
531 		set_bit(_IOC_NR(cmd), valid_ioctls)
532 
533 /* This determines which ioctls are actually implemented in the driver.
534    It's a one-time thing which simplifies video_ioctl2 as it can just do
535    a bit test.
536 
537    Note that drivers can override this by setting bits to 1 in
538    vdev->valid_ioctls. If an ioctl is marked as 1 when this function is
539    called, then that ioctl will actually be marked as unimplemented.
540 
541    It does that by first setting up the local valid_ioctls bitmap, and
542    at the end do a:
543 
544    vdev->valid_ioctls = valid_ioctls & ~(vdev->valid_ioctls)
545  */
546 static void determine_valid_ioctls(struct video_device *vdev)
547 {
548 	DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);
549 	const struct v4l2_ioctl_ops *ops = vdev->ioctl_ops;
550 	bool is_vid = vdev->vfl_type == VFL_TYPE_GRABBER;
551 	bool is_vbi = vdev->vfl_type == VFL_TYPE_VBI;
552 	bool is_radio = vdev->vfl_type == VFL_TYPE_RADIO;
553 	bool is_rx = vdev->vfl_dir != VFL_DIR_TX;
554 	bool is_tx = vdev->vfl_dir != VFL_DIR_RX;
555 
556 	bitmap_zero(valid_ioctls, BASE_VIDIOC_PRIVATE);
557 
558 	/* vfl_type and vfl_dir independent ioctls */
559 
560 	SET_VALID_IOCTL(ops, VIDIOC_QUERYCAP, vidioc_querycap);
561 	if (ops->vidioc_g_priority ||
562 			test_bit(V4L2_FL_USE_FH_PRIO, &vdev->flags))
563 		set_bit(_IOC_NR(VIDIOC_G_PRIORITY), valid_ioctls);
564 	if (ops->vidioc_s_priority ||
565 			test_bit(V4L2_FL_USE_FH_PRIO, &vdev->flags))
566 		set_bit(_IOC_NR(VIDIOC_S_PRIORITY), valid_ioctls);
567 	SET_VALID_IOCTL(ops, VIDIOC_STREAMON, vidioc_streamon);
568 	SET_VALID_IOCTL(ops, VIDIOC_STREAMOFF, vidioc_streamoff);
569 	/* Note: the control handler can also be passed through the filehandle,
570 	   and that can't be tested here. If the bit for these control ioctls
571 	   is set, then the ioctl is valid. But if it is 0, then it can still
572 	   be valid if the filehandle passed the control handler. */
573 	if (vdev->ctrl_handler || ops->vidioc_queryctrl)
574 		set_bit(_IOC_NR(VIDIOC_QUERYCTRL), valid_ioctls);
575 	if (vdev->ctrl_handler || ops->vidioc_g_ctrl || ops->vidioc_g_ext_ctrls)
576 		set_bit(_IOC_NR(VIDIOC_G_CTRL), valid_ioctls);
577 	if (vdev->ctrl_handler || ops->vidioc_s_ctrl || ops->vidioc_s_ext_ctrls)
578 		set_bit(_IOC_NR(VIDIOC_S_CTRL), valid_ioctls);
579 	if (vdev->ctrl_handler || ops->vidioc_g_ext_ctrls)
580 		set_bit(_IOC_NR(VIDIOC_G_EXT_CTRLS), valid_ioctls);
581 	if (vdev->ctrl_handler || ops->vidioc_s_ext_ctrls)
582 		set_bit(_IOC_NR(VIDIOC_S_EXT_CTRLS), valid_ioctls);
583 	if (vdev->ctrl_handler || ops->vidioc_try_ext_ctrls)
584 		set_bit(_IOC_NR(VIDIOC_TRY_EXT_CTRLS), valid_ioctls);
585 	if (vdev->ctrl_handler || ops->vidioc_querymenu)
586 		set_bit(_IOC_NR(VIDIOC_QUERYMENU), valid_ioctls);
587 	SET_VALID_IOCTL(ops, VIDIOC_G_FREQUENCY, vidioc_g_frequency);
588 	SET_VALID_IOCTL(ops, VIDIOC_S_FREQUENCY, vidioc_s_frequency);
589 	SET_VALID_IOCTL(ops, VIDIOC_LOG_STATUS, vidioc_log_status);
590 #ifdef CONFIG_VIDEO_ADV_DEBUG
591 	set_bit(_IOC_NR(VIDIOC_DBG_G_CHIP_INFO), valid_ioctls);
592 	set_bit(_IOC_NR(VIDIOC_DBG_G_REGISTER), valid_ioctls);
593 	set_bit(_IOC_NR(VIDIOC_DBG_S_REGISTER), valid_ioctls);
594 #endif
595 	/* yes, really vidioc_subscribe_event */
596 	SET_VALID_IOCTL(ops, VIDIOC_DQEVENT, vidioc_subscribe_event);
597 	SET_VALID_IOCTL(ops, VIDIOC_SUBSCRIBE_EVENT, vidioc_subscribe_event);
598 	SET_VALID_IOCTL(ops, VIDIOC_UNSUBSCRIBE_EVENT, vidioc_unsubscribe_event);
599 	if (ops->vidioc_enum_freq_bands || ops->vidioc_g_tuner || ops->vidioc_g_modulator)
600 		set_bit(_IOC_NR(VIDIOC_ENUM_FREQ_BANDS), valid_ioctls);
601 
602 	if (is_vid) {
603 		/* video specific ioctls */
604 		if ((is_rx && (ops->vidioc_enum_fmt_vid_cap ||
605 			       ops->vidioc_enum_fmt_vid_cap_mplane ||
606 			       ops->vidioc_enum_fmt_vid_overlay)) ||
607 		    (is_tx && (ops->vidioc_enum_fmt_vid_out ||
608 			       ops->vidioc_enum_fmt_vid_out_mplane)))
609 			set_bit(_IOC_NR(VIDIOC_ENUM_FMT), valid_ioctls);
610 		if ((is_rx && (ops->vidioc_g_fmt_vid_cap ||
611 			       ops->vidioc_g_fmt_vid_cap_mplane ||
612 			       ops->vidioc_g_fmt_vid_overlay)) ||
613 		    (is_tx && (ops->vidioc_g_fmt_vid_out ||
614 			       ops->vidioc_g_fmt_vid_out_mplane ||
615 			       ops->vidioc_g_fmt_vid_out_overlay)))
616 			 set_bit(_IOC_NR(VIDIOC_G_FMT), valid_ioctls);
617 		if ((is_rx && (ops->vidioc_s_fmt_vid_cap ||
618 			       ops->vidioc_s_fmt_vid_cap_mplane ||
619 			       ops->vidioc_s_fmt_vid_overlay)) ||
620 		    (is_tx && (ops->vidioc_s_fmt_vid_out ||
621 			       ops->vidioc_s_fmt_vid_out_mplane ||
622 			       ops->vidioc_s_fmt_vid_out_overlay)))
623 			 set_bit(_IOC_NR(VIDIOC_S_FMT), valid_ioctls);
624 		if ((is_rx && (ops->vidioc_try_fmt_vid_cap ||
625 			       ops->vidioc_try_fmt_vid_cap_mplane ||
626 			       ops->vidioc_try_fmt_vid_overlay)) ||
627 		    (is_tx && (ops->vidioc_try_fmt_vid_out ||
628 			       ops->vidioc_try_fmt_vid_out_mplane ||
629 			       ops->vidioc_try_fmt_vid_out_overlay)))
630 			 set_bit(_IOC_NR(VIDIOC_TRY_FMT), valid_ioctls);
631 		SET_VALID_IOCTL(ops, VIDIOC_OVERLAY, vidioc_overlay);
632 		SET_VALID_IOCTL(ops, VIDIOC_G_FBUF, vidioc_g_fbuf);
633 		SET_VALID_IOCTL(ops, VIDIOC_S_FBUF, vidioc_s_fbuf);
634 		SET_VALID_IOCTL(ops, VIDIOC_G_JPEGCOMP, vidioc_g_jpegcomp);
635 		SET_VALID_IOCTL(ops, VIDIOC_S_JPEGCOMP, vidioc_s_jpegcomp);
636 		SET_VALID_IOCTL(ops, VIDIOC_G_ENC_INDEX, vidioc_g_enc_index);
637 		SET_VALID_IOCTL(ops, VIDIOC_ENCODER_CMD, vidioc_encoder_cmd);
638 		SET_VALID_IOCTL(ops, VIDIOC_TRY_ENCODER_CMD, vidioc_try_encoder_cmd);
639 		SET_VALID_IOCTL(ops, VIDIOC_DECODER_CMD, vidioc_decoder_cmd);
640 		SET_VALID_IOCTL(ops, VIDIOC_TRY_DECODER_CMD, vidioc_try_decoder_cmd);
641 		SET_VALID_IOCTL(ops, VIDIOC_ENUM_FRAMESIZES, vidioc_enum_framesizes);
642 		SET_VALID_IOCTL(ops, VIDIOC_ENUM_FRAMEINTERVALS, vidioc_enum_frameintervals);
643 	} else if (is_vbi) {
644 		/* vbi specific ioctls */
645 		if ((is_rx && (ops->vidioc_g_fmt_vbi_cap ||
646 			       ops->vidioc_g_fmt_sliced_vbi_cap)) ||
647 		    (is_tx && (ops->vidioc_g_fmt_vbi_out ||
648 			       ops->vidioc_g_fmt_sliced_vbi_out)))
649 			set_bit(_IOC_NR(VIDIOC_G_FMT), valid_ioctls);
650 		if ((is_rx && (ops->vidioc_s_fmt_vbi_cap ||
651 			       ops->vidioc_s_fmt_sliced_vbi_cap)) ||
652 		    (is_tx && (ops->vidioc_s_fmt_vbi_out ||
653 			       ops->vidioc_s_fmt_sliced_vbi_out)))
654 			set_bit(_IOC_NR(VIDIOC_S_FMT), valid_ioctls);
655 		if ((is_rx && (ops->vidioc_try_fmt_vbi_cap ||
656 			       ops->vidioc_try_fmt_sliced_vbi_cap)) ||
657 		    (is_tx && (ops->vidioc_try_fmt_vbi_out ||
658 			       ops->vidioc_try_fmt_sliced_vbi_out)))
659 			set_bit(_IOC_NR(VIDIOC_TRY_FMT), valid_ioctls);
660 		SET_VALID_IOCTL(ops, VIDIOC_G_SLICED_VBI_CAP, vidioc_g_sliced_vbi_cap);
661 	}
662 	if (!is_radio) {
663 		/* ioctls valid for video or vbi */
664 		SET_VALID_IOCTL(ops, VIDIOC_REQBUFS, vidioc_reqbufs);
665 		SET_VALID_IOCTL(ops, VIDIOC_QUERYBUF, vidioc_querybuf);
666 		SET_VALID_IOCTL(ops, VIDIOC_QBUF, vidioc_qbuf);
667 		SET_VALID_IOCTL(ops, VIDIOC_EXPBUF, vidioc_expbuf);
668 		SET_VALID_IOCTL(ops, VIDIOC_DQBUF, vidioc_dqbuf);
669 		SET_VALID_IOCTL(ops, VIDIOC_CREATE_BUFS, vidioc_create_bufs);
670 		SET_VALID_IOCTL(ops, VIDIOC_PREPARE_BUF, vidioc_prepare_buf);
671 		if (ops->vidioc_s_std)
672 			set_bit(_IOC_NR(VIDIOC_ENUMSTD), valid_ioctls);
673 		SET_VALID_IOCTL(ops, VIDIOC_S_STD, vidioc_s_std);
674 		SET_VALID_IOCTL(ops, VIDIOC_G_STD, vidioc_g_std);
675 		if (is_rx) {
676 			SET_VALID_IOCTL(ops, VIDIOC_QUERYSTD, vidioc_querystd);
677 			SET_VALID_IOCTL(ops, VIDIOC_ENUMINPUT, vidioc_enum_input);
678 			SET_VALID_IOCTL(ops, VIDIOC_G_INPUT, vidioc_g_input);
679 			SET_VALID_IOCTL(ops, VIDIOC_S_INPUT, vidioc_s_input);
680 			SET_VALID_IOCTL(ops, VIDIOC_ENUMAUDIO, vidioc_enumaudio);
681 			SET_VALID_IOCTL(ops, VIDIOC_G_AUDIO, vidioc_g_audio);
682 			SET_VALID_IOCTL(ops, VIDIOC_S_AUDIO, vidioc_s_audio);
683 			SET_VALID_IOCTL(ops, VIDIOC_QUERY_DV_TIMINGS, vidioc_query_dv_timings);
684 		}
685 		if (is_tx) {
686 			SET_VALID_IOCTL(ops, VIDIOC_ENUMOUTPUT, vidioc_enum_output);
687 			SET_VALID_IOCTL(ops, VIDIOC_G_OUTPUT, vidioc_g_output);
688 			SET_VALID_IOCTL(ops, VIDIOC_S_OUTPUT, vidioc_s_output);
689 			SET_VALID_IOCTL(ops, VIDIOC_ENUMAUDOUT, vidioc_enumaudout);
690 			SET_VALID_IOCTL(ops, VIDIOC_G_AUDOUT, vidioc_g_audout);
691 			SET_VALID_IOCTL(ops, VIDIOC_S_AUDOUT, vidioc_s_audout);
692 		}
693 		if (ops->vidioc_g_crop || ops->vidioc_g_selection)
694 			set_bit(_IOC_NR(VIDIOC_G_CROP), valid_ioctls);
695 		if (ops->vidioc_s_crop || ops->vidioc_s_selection)
696 			set_bit(_IOC_NR(VIDIOC_S_CROP), valid_ioctls);
697 		SET_VALID_IOCTL(ops, VIDIOC_G_SELECTION, vidioc_g_selection);
698 		SET_VALID_IOCTL(ops, VIDIOC_S_SELECTION, vidioc_s_selection);
699 		if (ops->vidioc_cropcap || ops->vidioc_g_selection)
700 			set_bit(_IOC_NR(VIDIOC_CROPCAP), valid_ioctls);
701 		if (ops->vidioc_g_parm || (vdev->vfl_type == VFL_TYPE_GRABBER &&
702 					ops->vidioc_g_std))
703 			set_bit(_IOC_NR(VIDIOC_G_PARM), valid_ioctls);
704 		SET_VALID_IOCTL(ops, VIDIOC_S_PARM, vidioc_s_parm);
705 		SET_VALID_IOCTL(ops, VIDIOC_S_DV_TIMINGS, vidioc_s_dv_timings);
706 		SET_VALID_IOCTL(ops, VIDIOC_G_DV_TIMINGS, vidioc_g_dv_timings);
707 		SET_VALID_IOCTL(ops, VIDIOC_ENUM_DV_TIMINGS, vidioc_enum_dv_timings);
708 		SET_VALID_IOCTL(ops, VIDIOC_DV_TIMINGS_CAP, vidioc_dv_timings_cap);
709 	}
710 	if (is_tx) {
711 		/* transmitter only ioctls */
712 		SET_VALID_IOCTL(ops, VIDIOC_G_MODULATOR, vidioc_g_modulator);
713 		SET_VALID_IOCTL(ops, VIDIOC_S_MODULATOR, vidioc_s_modulator);
714 	}
715 	if (is_rx) {
716 		/* receiver only ioctls */
717 		SET_VALID_IOCTL(ops, VIDIOC_G_TUNER, vidioc_g_tuner);
718 		SET_VALID_IOCTL(ops, VIDIOC_S_TUNER, vidioc_s_tuner);
719 		SET_VALID_IOCTL(ops, VIDIOC_S_HW_FREQ_SEEK, vidioc_s_hw_freq_seek);
720 	}
721 
722 	bitmap_andnot(vdev->valid_ioctls, valid_ioctls, vdev->valid_ioctls,
723 			BASE_VIDIOC_PRIVATE);
724 }
725 
726 /**
727  *	__video_register_device - register video4linux devices
728  *	@vdev: video device structure we want to register
729  *	@type: type of device to register
730  *	@nr:   which device node number (0 == /dev/video0, 1 == /dev/video1, ...
731  *             -1 == first free)
732  *	@warn_if_nr_in_use: warn if the desired device node number
733  *	       was already in use and another number was chosen instead.
734  *	@owner: module that owns the video device node
735  *
736  *	The registration code assigns minor numbers and device node numbers
737  *	based on the requested type and registers the new device node with
738  *	the kernel.
739  *
740  *	This function assumes that struct video_device was zeroed when it
741  *	was allocated and does not contain any stale date.
742  *
743  *	An error is returned if no free minor or device node number could be
744  *	found, or if the registration of the device node failed.
745  *
746  *	Zero is returned on success.
747  *
748  *	Valid types are
749  *
750  *	%VFL_TYPE_GRABBER - A frame grabber
751  *
752  *	%VFL_TYPE_VBI - Vertical blank data (undecoded)
753  *
754  *	%VFL_TYPE_RADIO - A radio card
755  *
756  *	%VFL_TYPE_SUBDEV - A subdevice
757  */
758 int __video_register_device(struct video_device *vdev, int type, int nr,
759 		int warn_if_nr_in_use, struct module *owner)
760 {
761 	int i = 0;
762 	int ret;
763 	int minor_offset = 0;
764 	int minor_cnt = VIDEO_NUM_DEVICES;
765 	const char *name_base;
766 
767 	/* A minor value of -1 marks this video device as never
768 	   having been registered */
769 	vdev->minor = -1;
770 
771 	/* the release callback MUST be present */
772 	if (WARN_ON(!vdev->release))
773 		return -EINVAL;
774 	/* the v4l2_dev pointer MUST be present */
775 	if (WARN_ON(!vdev->v4l2_dev))
776 		return -EINVAL;
777 
778 	/* v4l2_fh support */
779 	spin_lock_init(&vdev->fh_lock);
780 	INIT_LIST_HEAD(&vdev->fh_list);
781 
782 	/* Part 1: check device type */
783 	switch (type) {
784 	case VFL_TYPE_GRABBER:
785 		name_base = "video";
786 		break;
787 	case VFL_TYPE_VBI:
788 		name_base = "vbi";
789 		break;
790 	case VFL_TYPE_RADIO:
791 		name_base = "radio";
792 		break;
793 	case VFL_TYPE_SUBDEV:
794 		name_base = "v4l-subdev";
795 		break;
796 	default:
797 		printk(KERN_ERR "%s called with unknown type: %d\n",
798 		       __func__, type);
799 		return -EINVAL;
800 	}
801 
802 	vdev->vfl_type = type;
803 	vdev->cdev = NULL;
804 	if (vdev->dev_parent == NULL)
805 		vdev->dev_parent = vdev->v4l2_dev->dev;
806 	if (vdev->ctrl_handler == NULL)
807 		vdev->ctrl_handler = vdev->v4l2_dev->ctrl_handler;
808 	/* If the prio state pointer is NULL, then use the v4l2_device
809 	   prio state. */
810 	if (vdev->prio == NULL)
811 		vdev->prio = &vdev->v4l2_dev->prio;
812 
813 	/* Part 2: find a free minor, device node number and device index. */
814 #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
815 	/* Keep the ranges for the first four types for historical
816 	 * reasons.
817 	 * Newer devices (not yet in place) should use the range
818 	 * of 128-191 and just pick the first free minor there
819 	 * (new style). */
820 	switch (type) {
821 	case VFL_TYPE_GRABBER:
822 		minor_offset = 0;
823 		minor_cnt = 64;
824 		break;
825 	case VFL_TYPE_RADIO:
826 		minor_offset = 64;
827 		minor_cnt = 64;
828 		break;
829 	case VFL_TYPE_VBI:
830 		minor_offset = 224;
831 		minor_cnt = 32;
832 		break;
833 	default:
834 		minor_offset = 128;
835 		minor_cnt = 64;
836 		break;
837 	}
838 #endif
839 
840 	/* Pick a device node number */
841 	mutex_lock(&videodev_lock);
842 	nr = devnode_find(vdev, nr == -1 ? 0 : nr, minor_cnt);
843 	if (nr == minor_cnt)
844 		nr = devnode_find(vdev, 0, minor_cnt);
845 	if (nr == minor_cnt) {
846 		printk(KERN_ERR "could not get a free device node number\n");
847 		mutex_unlock(&videodev_lock);
848 		return -ENFILE;
849 	}
850 #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
851 	/* 1-on-1 mapping of device node number to minor number */
852 	i = nr;
853 #else
854 	/* The device node number and minor numbers are independent, so
855 	   we just find the first free minor number. */
856 	for (i = 0; i < VIDEO_NUM_DEVICES; i++)
857 		if (video_device[i] == NULL)
858 			break;
859 	if (i == VIDEO_NUM_DEVICES) {
860 		mutex_unlock(&videodev_lock);
861 		printk(KERN_ERR "could not get a free minor\n");
862 		return -ENFILE;
863 	}
864 #endif
865 	vdev->minor = i + minor_offset;
866 	vdev->num = nr;
867 	devnode_set(vdev);
868 
869 	/* Should not happen since we thought this minor was free */
870 	WARN_ON(video_device[vdev->minor] != NULL);
871 	vdev->index = get_index(vdev);
872 	mutex_unlock(&videodev_lock);
873 
874 	if (vdev->ioctl_ops)
875 		determine_valid_ioctls(vdev);
876 
877 	/* Part 3: Initialize the character device */
878 	vdev->cdev = cdev_alloc();
879 	if (vdev->cdev == NULL) {
880 		ret = -ENOMEM;
881 		goto cleanup;
882 	}
883 	vdev->cdev->ops = &v4l2_fops;
884 	vdev->cdev->owner = owner;
885 	ret = cdev_add(vdev->cdev, MKDEV(VIDEO_MAJOR, vdev->minor), 1);
886 	if (ret < 0) {
887 		printk(KERN_ERR "%s: cdev_add failed\n", __func__);
888 		kfree(vdev->cdev);
889 		vdev->cdev = NULL;
890 		goto cleanup;
891 	}
892 
893 	/* Part 4: register the device with sysfs */
894 	vdev->dev.class = &video_class;
895 	vdev->dev.devt = MKDEV(VIDEO_MAJOR, vdev->minor);
896 	vdev->dev.parent = vdev->dev_parent;
897 	dev_set_name(&vdev->dev, "%s%d", name_base, vdev->num);
898 	ret = device_register(&vdev->dev);
899 	if (ret < 0) {
900 		printk(KERN_ERR "%s: device_register failed\n", __func__);
901 		goto cleanup;
902 	}
903 	/* Register the release callback that will be called when the last
904 	   reference to the device goes away. */
905 	vdev->dev.release = v4l2_device_release;
906 
907 	if (nr != -1 && nr != vdev->num && warn_if_nr_in_use)
908 		printk(KERN_WARNING "%s: requested %s%d, got %s\n", __func__,
909 			name_base, nr, video_device_node_name(vdev));
910 
911 	/* Increase v4l2_device refcount */
912 	if (vdev->v4l2_dev)
913 		v4l2_device_get(vdev->v4l2_dev);
914 
915 #if defined(CONFIG_MEDIA_CONTROLLER)
916 	/* Part 5: Register the entity. */
917 	if (vdev->v4l2_dev && vdev->v4l2_dev->mdev &&
918 	    vdev->vfl_type != VFL_TYPE_SUBDEV) {
919 		vdev->entity.type = MEDIA_ENT_T_DEVNODE_V4L;
920 		vdev->entity.name = vdev->name;
921 		vdev->entity.info.v4l.major = VIDEO_MAJOR;
922 		vdev->entity.info.v4l.minor = vdev->minor;
923 		ret = media_device_register_entity(vdev->v4l2_dev->mdev,
924 			&vdev->entity);
925 		if (ret < 0)
926 			printk(KERN_WARNING
927 			       "%s: media_device_register_entity failed\n",
928 			       __func__);
929 	}
930 #endif
931 	/* Part 6: Activate this minor. The char device can now be used. */
932 	set_bit(V4L2_FL_REGISTERED, &vdev->flags);
933 	mutex_lock(&videodev_lock);
934 	video_device[vdev->minor] = vdev;
935 	mutex_unlock(&videodev_lock);
936 
937 	return 0;
938 
939 cleanup:
940 	mutex_lock(&videodev_lock);
941 	if (vdev->cdev)
942 		cdev_del(vdev->cdev);
943 	devnode_clear(vdev);
944 	mutex_unlock(&videodev_lock);
945 	/* Mark this video device as never having been registered. */
946 	vdev->minor = -1;
947 	return ret;
948 }
949 EXPORT_SYMBOL(__video_register_device);
950 
951 /**
952  *	video_unregister_device - unregister a video4linux device
953  *	@vdev: the device to unregister
954  *
955  *	This unregisters the passed device. Future open calls will
956  *	be met with errors.
957  */
958 void video_unregister_device(struct video_device *vdev)
959 {
960 	/* Check if vdev was ever registered at all */
961 	if (!vdev || !video_is_registered(vdev))
962 		return;
963 
964 	mutex_lock(&videodev_lock);
965 	/* This must be in a critical section to prevent a race with v4l2_open.
966 	 * Once this bit has been cleared video_get may never be called again.
967 	 */
968 	clear_bit(V4L2_FL_REGISTERED, &vdev->flags);
969 	mutex_unlock(&videodev_lock);
970 	device_unregister(&vdev->dev);
971 }
972 EXPORT_SYMBOL(video_unregister_device);
973 
974 /*
975  *	Initialise video for linux
976  */
977 static int __init videodev_init(void)
978 {
979 	dev_t dev = MKDEV(VIDEO_MAJOR, 0);
980 	int ret;
981 
982 	printk(KERN_INFO "Linux video capture interface: v2.00\n");
983 	ret = register_chrdev_region(dev, VIDEO_NUM_DEVICES, VIDEO_NAME);
984 	if (ret < 0) {
985 		printk(KERN_WARNING "videodev: unable to get major %d\n",
986 				VIDEO_MAJOR);
987 		return ret;
988 	}
989 
990 	ret = class_register(&video_class);
991 	if (ret < 0) {
992 		unregister_chrdev_region(dev, VIDEO_NUM_DEVICES);
993 		printk(KERN_WARNING "video_dev: class_register failed\n");
994 		return -EIO;
995 	}
996 
997 	return 0;
998 }
999 
1000 static void __exit videodev_exit(void)
1001 {
1002 	dev_t dev = MKDEV(VIDEO_MAJOR, 0);
1003 
1004 	class_unregister(&video_class);
1005 	unregister_chrdev_region(dev, VIDEO_NUM_DEVICES);
1006 }
1007 
1008 subsys_initcall(videodev_init);
1009 module_exit(videodev_exit)
1010 
1011 MODULE_AUTHOR("Alan Cox, Mauro Carvalho Chehab <mchehab@infradead.org>");
1012 MODULE_DESCRIPTION("Device registrar for Video4Linux drivers v2");
1013 MODULE_LICENSE("GPL");
1014 MODULE_ALIAS_CHARDEV_MAJOR(VIDEO_MAJOR);
1015 
1016 
1017 /*
1018  * Local variables:
1019  * c-basic-offset: 8
1020  * End:
1021  */
1022