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 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(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->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->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->dev_debug & V4L2_DEV_DEBUG_FOP) &&
308 	    (vdev->dev_debug & V4L2_DEV_DEBUG_STREAMING))
309 		printk(KERN_DEBUG "%s: read: %zd (%d)\n",
310 			video_device_node_name(vdev), sz, ret);
311 	return ret;
312 }
313 
314 static ssize_t v4l2_write(struct file *filp, const char __user *buf,
315 		size_t sz, loff_t *off)
316 {
317 	struct video_device *vdev = video_devdata(filp);
318 	int ret = -ENODEV;
319 
320 	if (!vdev->fops->write)
321 		return -EINVAL;
322 	if (video_is_registered(vdev))
323 		ret = vdev->fops->write(filp, buf, sz, off);
324 	if ((vdev->dev_debug & V4L2_DEV_DEBUG_FOP) &&
325 	    (vdev->dev_debug & V4L2_DEV_DEBUG_STREAMING))
326 		printk(KERN_DEBUG "%s: write: %zd (%d)\n",
327 			video_device_node_name(vdev), sz, ret);
328 	return ret;
329 }
330 
331 static unsigned int v4l2_poll(struct file *filp, struct poll_table_struct *poll)
332 {
333 	struct video_device *vdev = video_devdata(filp);
334 	unsigned int res = POLLERR | POLLHUP;
335 
336 	if (!vdev->fops->poll)
337 		return DEFAULT_POLLMASK;
338 	if (video_is_registered(vdev))
339 		res = vdev->fops->poll(filp, poll);
340 	if (vdev->dev_debug & V4L2_DEV_DEBUG_POLL)
341 		printk(KERN_DEBUG "%s: poll: %08x\n",
342 			video_device_node_name(vdev), res);
343 	return res;
344 }
345 
346 static long v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
347 {
348 	struct video_device *vdev = video_devdata(filp);
349 	int ret = -ENODEV;
350 
351 	if (vdev->fops->unlocked_ioctl) {
352 		struct mutex *lock = v4l2_ioctl_get_lock(vdev, cmd);
353 
354 		if (lock && mutex_lock_interruptible(lock))
355 			return -ERESTARTSYS;
356 		if (video_is_registered(vdev))
357 			ret = vdev->fops->unlocked_ioctl(filp, cmd, arg);
358 		if (lock)
359 			mutex_unlock(lock);
360 	} else
361 		ret = -ENOTTY;
362 
363 	return ret;
364 }
365 
366 #ifdef CONFIG_MMU
367 #define v4l2_get_unmapped_area NULL
368 #else
369 static unsigned long v4l2_get_unmapped_area(struct file *filp,
370 		unsigned long addr, unsigned long len, unsigned long pgoff,
371 		unsigned long flags)
372 {
373 	struct video_device *vdev = video_devdata(filp);
374 	int ret;
375 
376 	if (!vdev->fops->get_unmapped_area)
377 		return -ENOSYS;
378 	if (!video_is_registered(vdev))
379 		return -ENODEV;
380 	ret = vdev->fops->get_unmapped_area(filp, addr, len, pgoff, flags);
381 	if (vdev->dev_debug & V4L2_DEV_DEBUG_FOP)
382 		printk(KERN_DEBUG "%s: get_unmapped_area (%d)\n",
383 			video_device_node_name(vdev), ret);
384 	return ret;
385 }
386 #endif
387 
388 static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm)
389 {
390 	struct video_device *vdev = video_devdata(filp);
391 	int ret = -ENODEV;
392 
393 	if (!vdev->fops->mmap)
394 		return -ENODEV;
395 	if (video_is_registered(vdev))
396 		ret = vdev->fops->mmap(filp, vm);
397 	if (vdev->dev_debug & V4L2_DEV_DEBUG_FOP)
398 		printk(KERN_DEBUG "%s: mmap (%d)\n",
399 			video_device_node_name(vdev), ret);
400 	return ret;
401 }
402 
403 /* Override for the open function */
404 static int v4l2_open(struct inode *inode, struct file *filp)
405 {
406 	struct video_device *vdev;
407 	int ret = 0;
408 
409 	/* Check if the video device is available */
410 	mutex_lock(&videodev_lock);
411 	vdev = video_devdata(filp);
412 	/* return ENODEV if the video device has already been removed. */
413 	if (vdev == NULL || !video_is_registered(vdev)) {
414 		mutex_unlock(&videodev_lock);
415 		return -ENODEV;
416 	}
417 	/* and increase the device refcount */
418 	video_get(vdev);
419 	mutex_unlock(&videodev_lock);
420 	if (vdev->fops->open) {
421 		if (video_is_registered(vdev))
422 			ret = vdev->fops->open(filp);
423 		else
424 			ret = -ENODEV;
425 	}
426 
427 	if (vdev->dev_debug & V4L2_DEV_DEBUG_FOP)
428 		printk(KERN_DEBUG "%s: open (%d)\n",
429 			video_device_node_name(vdev), ret);
430 	/* decrease the refcount in case of an error */
431 	if (ret)
432 		video_put(vdev);
433 	return ret;
434 }
435 
436 /* Override for the release function */
437 static int v4l2_release(struct inode *inode, struct file *filp)
438 {
439 	struct video_device *vdev = video_devdata(filp);
440 	int ret = 0;
441 
442 	if (vdev->fops->release)
443 		ret = vdev->fops->release(filp);
444 	if (vdev->dev_debug & V4L2_DEV_DEBUG_FOP)
445 		printk(KERN_DEBUG "%s: release\n",
446 			video_device_node_name(vdev));
447 
448 	/* decrease the refcount unconditionally since the release()
449 	   return value is ignored. */
450 	video_put(vdev);
451 	return ret;
452 }
453 
454 static const struct file_operations v4l2_fops = {
455 	.owner = THIS_MODULE,
456 	.read = v4l2_read,
457 	.write = v4l2_write,
458 	.open = v4l2_open,
459 	.get_unmapped_area = v4l2_get_unmapped_area,
460 	.mmap = v4l2_mmap,
461 	.unlocked_ioctl = v4l2_ioctl,
462 #ifdef CONFIG_COMPAT
463 	.compat_ioctl = v4l2_compat_ioctl32,
464 #endif
465 	.release = v4l2_release,
466 	.poll = v4l2_poll,
467 	.llseek = no_llseek,
468 };
469 
470 /**
471  * get_index - assign stream index number based on v4l2_dev
472  * @vdev: video_device to assign index number to, vdev->v4l2_dev should be assigned
473  *
474  * Note that when this is called the new device has not yet been registered
475  * in the video_device array, but it was able to obtain a minor number.
476  *
477  * This means that we can always obtain a free stream index number since
478  * the worst case scenario is that there are VIDEO_NUM_DEVICES - 1 slots in
479  * use of the video_device array.
480  *
481  * Returns a free index number.
482  */
483 static int get_index(struct video_device *vdev)
484 {
485 	/* This can be static since this function is called with the global
486 	   videodev_lock held. */
487 	static DECLARE_BITMAP(used, VIDEO_NUM_DEVICES);
488 	int i;
489 
490 	bitmap_zero(used, VIDEO_NUM_DEVICES);
491 
492 	for (i = 0; i < VIDEO_NUM_DEVICES; i++) {
493 		if (video_device[i] != NULL &&
494 		    video_device[i]->v4l2_dev == vdev->v4l2_dev) {
495 			set_bit(video_device[i]->index, used);
496 		}
497 	}
498 
499 	return find_first_zero_bit(used, VIDEO_NUM_DEVICES);
500 }
501 
502 #define SET_VALID_IOCTL(ops, cmd, op)			\
503 	if (ops->op)					\
504 		set_bit(_IOC_NR(cmd), valid_ioctls)
505 
506 /* This determines which ioctls are actually implemented in the driver.
507    It's a one-time thing which simplifies video_ioctl2 as it can just do
508    a bit test.
509 
510    Note that drivers can override this by setting bits to 1 in
511    vdev->valid_ioctls. If an ioctl is marked as 1 when this function is
512    called, then that ioctl will actually be marked as unimplemented.
513 
514    It does that by first setting up the local valid_ioctls bitmap, and
515    at the end do a:
516 
517    vdev->valid_ioctls = valid_ioctls & ~(vdev->valid_ioctls)
518  */
519 static void determine_valid_ioctls(struct video_device *vdev)
520 {
521 	DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);
522 	const struct v4l2_ioctl_ops *ops = vdev->ioctl_ops;
523 	bool is_vid = vdev->vfl_type == VFL_TYPE_GRABBER;
524 	bool is_vbi = vdev->vfl_type == VFL_TYPE_VBI;
525 	bool is_radio = vdev->vfl_type == VFL_TYPE_RADIO;
526 	bool is_sdr = vdev->vfl_type == VFL_TYPE_SDR;
527 	bool is_rx = vdev->vfl_dir != VFL_DIR_TX;
528 	bool is_tx = vdev->vfl_dir != VFL_DIR_RX;
529 
530 	bitmap_zero(valid_ioctls, BASE_VIDIOC_PRIVATE);
531 
532 	/* vfl_type and vfl_dir independent ioctls */
533 
534 	SET_VALID_IOCTL(ops, VIDIOC_QUERYCAP, vidioc_querycap);
535 	set_bit(_IOC_NR(VIDIOC_G_PRIORITY), valid_ioctls);
536 	set_bit(_IOC_NR(VIDIOC_S_PRIORITY), valid_ioctls);
537 
538 	/* Note: the control handler can also be passed through the filehandle,
539 	   and that can't be tested here. If the bit for these control ioctls
540 	   is set, then the ioctl is valid. But if it is 0, then it can still
541 	   be valid if the filehandle passed the control handler. */
542 	if (vdev->ctrl_handler || ops->vidioc_queryctrl)
543 		set_bit(_IOC_NR(VIDIOC_QUERYCTRL), valid_ioctls);
544 	if (vdev->ctrl_handler || ops->vidioc_query_ext_ctrl)
545 		set_bit(_IOC_NR(VIDIOC_QUERY_EXT_CTRL), valid_ioctls);
546 	if (vdev->ctrl_handler || ops->vidioc_g_ctrl || ops->vidioc_g_ext_ctrls)
547 		set_bit(_IOC_NR(VIDIOC_G_CTRL), valid_ioctls);
548 	if (vdev->ctrl_handler || ops->vidioc_s_ctrl || ops->vidioc_s_ext_ctrls)
549 		set_bit(_IOC_NR(VIDIOC_S_CTRL), valid_ioctls);
550 	if (vdev->ctrl_handler || ops->vidioc_g_ext_ctrls)
551 		set_bit(_IOC_NR(VIDIOC_G_EXT_CTRLS), valid_ioctls);
552 	if (vdev->ctrl_handler || ops->vidioc_s_ext_ctrls)
553 		set_bit(_IOC_NR(VIDIOC_S_EXT_CTRLS), valid_ioctls);
554 	if (vdev->ctrl_handler || ops->vidioc_try_ext_ctrls)
555 		set_bit(_IOC_NR(VIDIOC_TRY_EXT_CTRLS), valid_ioctls);
556 	if (vdev->ctrl_handler || ops->vidioc_querymenu)
557 		set_bit(_IOC_NR(VIDIOC_QUERYMENU), valid_ioctls);
558 	SET_VALID_IOCTL(ops, VIDIOC_G_FREQUENCY, vidioc_g_frequency);
559 	SET_VALID_IOCTL(ops, VIDIOC_S_FREQUENCY, vidioc_s_frequency);
560 	SET_VALID_IOCTL(ops, VIDIOC_LOG_STATUS, vidioc_log_status);
561 #ifdef CONFIG_VIDEO_ADV_DEBUG
562 	set_bit(_IOC_NR(VIDIOC_DBG_G_CHIP_INFO), valid_ioctls);
563 	set_bit(_IOC_NR(VIDIOC_DBG_G_REGISTER), valid_ioctls);
564 	set_bit(_IOC_NR(VIDIOC_DBG_S_REGISTER), valid_ioctls);
565 #endif
566 	/* yes, really vidioc_subscribe_event */
567 	SET_VALID_IOCTL(ops, VIDIOC_DQEVENT, vidioc_subscribe_event);
568 	SET_VALID_IOCTL(ops, VIDIOC_SUBSCRIBE_EVENT, vidioc_subscribe_event);
569 	SET_VALID_IOCTL(ops, VIDIOC_UNSUBSCRIBE_EVENT, vidioc_unsubscribe_event);
570 	if (ops->vidioc_enum_freq_bands || ops->vidioc_g_tuner || ops->vidioc_g_modulator)
571 		set_bit(_IOC_NR(VIDIOC_ENUM_FREQ_BANDS), valid_ioctls);
572 
573 	if (is_vid) {
574 		/* video specific ioctls */
575 		if ((is_rx && (ops->vidioc_enum_fmt_vid_cap ||
576 			       ops->vidioc_enum_fmt_vid_cap_mplane ||
577 			       ops->vidioc_enum_fmt_vid_overlay)) ||
578 		    (is_tx && (ops->vidioc_enum_fmt_vid_out ||
579 			       ops->vidioc_enum_fmt_vid_out_mplane)))
580 			set_bit(_IOC_NR(VIDIOC_ENUM_FMT), valid_ioctls);
581 		if ((is_rx && (ops->vidioc_g_fmt_vid_cap ||
582 			       ops->vidioc_g_fmt_vid_cap_mplane ||
583 			       ops->vidioc_g_fmt_vid_overlay)) ||
584 		    (is_tx && (ops->vidioc_g_fmt_vid_out ||
585 			       ops->vidioc_g_fmt_vid_out_mplane ||
586 			       ops->vidioc_g_fmt_vid_out_overlay)))
587 			 set_bit(_IOC_NR(VIDIOC_G_FMT), valid_ioctls);
588 		if ((is_rx && (ops->vidioc_s_fmt_vid_cap ||
589 			       ops->vidioc_s_fmt_vid_cap_mplane ||
590 			       ops->vidioc_s_fmt_vid_overlay)) ||
591 		    (is_tx && (ops->vidioc_s_fmt_vid_out ||
592 			       ops->vidioc_s_fmt_vid_out_mplane ||
593 			       ops->vidioc_s_fmt_vid_out_overlay)))
594 			 set_bit(_IOC_NR(VIDIOC_S_FMT), valid_ioctls);
595 		if ((is_rx && (ops->vidioc_try_fmt_vid_cap ||
596 			       ops->vidioc_try_fmt_vid_cap_mplane ||
597 			       ops->vidioc_try_fmt_vid_overlay)) ||
598 		    (is_tx && (ops->vidioc_try_fmt_vid_out ||
599 			       ops->vidioc_try_fmt_vid_out_mplane ||
600 			       ops->vidioc_try_fmt_vid_out_overlay)))
601 			 set_bit(_IOC_NR(VIDIOC_TRY_FMT), valid_ioctls);
602 		SET_VALID_IOCTL(ops, VIDIOC_OVERLAY, vidioc_overlay);
603 		SET_VALID_IOCTL(ops, VIDIOC_G_FBUF, vidioc_g_fbuf);
604 		SET_VALID_IOCTL(ops, VIDIOC_S_FBUF, vidioc_s_fbuf);
605 		SET_VALID_IOCTL(ops, VIDIOC_G_JPEGCOMP, vidioc_g_jpegcomp);
606 		SET_VALID_IOCTL(ops, VIDIOC_S_JPEGCOMP, vidioc_s_jpegcomp);
607 		SET_VALID_IOCTL(ops, VIDIOC_G_ENC_INDEX, vidioc_g_enc_index);
608 		SET_VALID_IOCTL(ops, VIDIOC_ENCODER_CMD, vidioc_encoder_cmd);
609 		SET_VALID_IOCTL(ops, VIDIOC_TRY_ENCODER_CMD, vidioc_try_encoder_cmd);
610 		SET_VALID_IOCTL(ops, VIDIOC_DECODER_CMD, vidioc_decoder_cmd);
611 		SET_VALID_IOCTL(ops, VIDIOC_TRY_DECODER_CMD, vidioc_try_decoder_cmd);
612 		SET_VALID_IOCTL(ops, VIDIOC_ENUM_FRAMESIZES, vidioc_enum_framesizes);
613 		SET_VALID_IOCTL(ops, VIDIOC_ENUM_FRAMEINTERVALS, vidioc_enum_frameintervals);
614 		if (ops->vidioc_g_crop || ops->vidioc_g_selection)
615 			set_bit(_IOC_NR(VIDIOC_G_CROP), valid_ioctls);
616 		if (ops->vidioc_s_crop || ops->vidioc_s_selection)
617 			set_bit(_IOC_NR(VIDIOC_S_CROP), valid_ioctls);
618 		SET_VALID_IOCTL(ops, VIDIOC_G_SELECTION, vidioc_g_selection);
619 		SET_VALID_IOCTL(ops, VIDIOC_S_SELECTION, vidioc_s_selection);
620 		if (ops->vidioc_cropcap || ops->vidioc_g_selection)
621 			set_bit(_IOC_NR(VIDIOC_CROPCAP), valid_ioctls);
622 	} else if (is_vbi) {
623 		/* vbi specific ioctls */
624 		if ((is_rx && (ops->vidioc_g_fmt_vbi_cap ||
625 			       ops->vidioc_g_fmt_sliced_vbi_cap)) ||
626 		    (is_tx && (ops->vidioc_g_fmt_vbi_out ||
627 			       ops->vidioc_g_fmt_sliced_vbi_out)))
628 			set_bit(_IOC_NR(VIDIOC_G_FMT), valid_ioctls);
629 		if ((is_rx && (ops->vidioc_s_fmt_vbi_cap ||
630 			       ops->vidioc_s_fmt_sliced_vbi_cap)) ||
631 		    (is_tx && (ops->vidioc_s_fmt_vbi_out ||
632 			       ops->vidioc_s_fmt_sliced_vbi_out)))
633 			set_bit(_IOC_NR(VIDIOC_S_FMT), valid_ioctls);
634 		if ((is_rx && (ops->vidioc_try_fmt_vbi_cap ||
635 			       ops->vidioc_try_fmt_sliced_vbi_cap)) ||
636 		    (is_tx && (ops->vidioc_try_fmt_vbi_out ||
637 			       ops->vidioc_try_fmt_sliced_vbi_out)))
638 			set_bit(_IOC_NR(VIDIOC_TRY_FMT), valid_ioctls);
639 		SET_VALID_IOCTL(ops, VIDIOC_G_SLICED_VBI_CAP, vidioc_g_sliced_vbi_cap);
640 	} else if (is_sdr) {
641 		/* SDR specific ioctls */
642 		if (ops->vidioc_enum_fmt_sdr_cap)
643 			set_bit(_IOC_NR(VIDIOC_ENUM_FMT), valid_ioctls);
644 		if (ops->vidioc_g_fmt_sdr_cap)
645 			set_bit(_IOC_NR(VIDIOC_G_FMT), valid_ioctls);
646 		if (ops->vidioc_s_fmt_sdr_cap)
647 			set_bit(_IOC_NR(VIDIOC_S_FMT), valid_ioctls);
648 		if (ops->vidioc_try_fmt_sdr_cap)
649 			set_bit(_IOC_NR(VIDIOC_TRY_FMT), valid_ioctls);
650 	}
651 
652 	if (is_vid || is_vbi || is_sdr) {
653 		/* ioctls valid for video, vbi or sdr */
654 		SET_VALID_IOCTL(ops, VIDIOC_REQBUFS, vidioc_reqbufs);
655 		SET_VALID_IOCTL(ops, VIDIOC_QUERYBUF, vidioc_querybuf);
656 		SET_VALID_IOCTL(ops, VIDIOC_QBUF, vidioc_qbuf);
657 		SET_VALID_IOCTL(ops, VIDIOC_EXPBUF, vidioc_expbuf);
658 		SET_VALID_IOCTL(ops, VIDIOC_DQBUF, vidioc_dqbuf);
659 		SET_VALID_IOCTL(ops, VIDIOC_CREATE_BUFS, vidioc_create_bufs);
660 		SET_VALID_IOCTL(ops, VIDIOC_PREPARE_BUF, vidioc_prepare_buf);
661 		SET_VALID_IOCTL(ops, VIDIOC_STREAMON, vidioc_streamon);
662 		SET_VALID_IOCTL(ops, VIDIOC_STREAMOFF, vidioc_streamoff);
663 	}
664 
665 	if (is_vid || is_vbi) {
666 		/* ioctls valid for video or vbi */
667 		if (ops->vidioc_s_std)
668 			set_bit(_IOC_NR(VIDIOC_ENUMSTD), valid_ioctls);
669 		SET_VALID_IOCTL(ops, VIDIOC_S_STD, vidioc_s_std);
670 		SET_VALID_IOCTL(ops, VIDIOC_G_STD, vidioc_g_std);
671 		if (is_rx) {
672 			SET_VALID_IOCTL(ops, VIDIOC_QUERYSTD, vidioc_querystd);
673 			SET_VALID_IOCTL(ops, VIDIOC_ENUMINPUT, vidioc_enum_input);
674 			SET_VALID_IOCTL(ops, VIDIOC_G_INPUT, vidioc_g_input);
675 			SET_VALID_IOCTL(ops, VIDIOC_S_INPUT, vidioc_s_input);
676 			SET_VALID_IOCTL(ops, VIDIOC_ENUMAUDIO, vidioc_enumaudio);
677 			SET_VALID_IOCTL(ops, VIDIOC_G_AUDIO, vidioc_g_audio);
678 			SET_VALID_IOCTL(ops, VIDIOC_S_AUDIO, vidioc_s_audio);
679 			SET_VALID_IOCTL(ops, VIDIOC_QUERY_DV_TIMINGS, vidioc_query_dv_timings);
680 			SET_VALID_IOCTL(ops, VIDIOC_S_EDID, vidioc_s_edid);
681 		}
682 		if (is_tx) {
683 			SET_VALID_IOCTL(ops, VIDIOC_ENUMOUTPUT, vidioc_enum_output);
684 			SET_VALID_IOCTL(ops, VIDIOC_G_OUTPUT, vidioc_g_output);
685 			SET_VALID_IOCTL(ops, VIDIOC_S_OUTPUT, vidioc_s_output);
686 			SET_VALID_IOCTL(ops, VIDIOC_ENUMAUDOUT, vidioc_enumaudout);
687 			SET_VALID_IOCTL(ops, VIDIOC_G_AUDOUT, vidioc_g_audout);
688 			SET_VALID_IOCTL(ops, VIDIOC_S_AUDOUT, vidioc_s_audout);
689 		}
690 		if (ops->vidioc_g_parm || (vdev->vfl_type == VFL_TYPE_GRABBER &&
691 					ops->vidioc_g_std))
692 			set_bit(_IOC_NR(VIDIOC_G_PARM), valid_ioctls);
693 		SET_VALID_IOCTL(ops, VIDIOC_S_PARM, vidioc_s_parm);
694 		SET_VALID_IOCTL(ops, VIDIOC_S_DV_TIMINGS, vidioc_s_dv_timings);
695 		SET_VALID_IOCTL(ops, VIDIOC_G_DV_TIMINGS, vidioc_g_dv_timings);
696 		SET_VALID_IOCTL(ops, VIDIOC_ENUM_DV_TIMINGS, vidioc_enum_dv_timings);
697 		SET_VALID_IOCTL(ops, VIDIOC_DV_TIMINGS_CAP, vidioc_dv_timings_cap);
698 		SET_VALID_IOCTL(ops, VIDIOC_G_EDID, vidioc_g_edid);
699 	}
700 	if (is_tx && (is_radio || is_sdr)) {
701 		/* radio transmitter only ioctls */
702 		SET_VALID_IOCTL(ops, VIDIOC_G_MODULATOR, vidioc_g_modulator);
703 		SET_VALID_IOCTL(ops, VIDIOC_S_MODULATOR, vidioc_s_modulator);
704 	}
705 	if (is_rx) {
706 		/* receiver only ioctls */
707 		SET_VALID_IOCTL(ops, VIDIOC_G_TUNER, vidioc_g_tuner);
708 		SET_VALID_IOCTL(ops, VIDIOC_S_TUNER, vidioc_s_tuner);
709 		SET_VALID_IOCTL(ops, VIDIOC_S_HW_FREQ_SEEK, vidioc_s_hw_freq_seek);
710 	}
711 
712 	bitmap_andnot(vdev->valid_ioctls, valid_ioctls, vdev->valid_ioctls,
713 			BASE_VIDIOC_PRIVATE);
714 }
715 
716 /**
717  *	__video_register_device - register video4linux devices
718  *	@vdev: video device structure we want to register
719  *	@type: type of device to register
720  *	@nr:   which device node number (0 == /dev/video0, 1 == /dev/video1, ...
721  *             -1 == first free)
722  *	@warn_if_nr_in_use: warn if the desired device node number
723  *	       was already in use and another number was chosen instead.
724  *	@owner: module that owns the video device node
725  *
726  *	The registration code assigns minor numbers and device node numbers
727  *	based on the requested type and registers the new device node with
728  *	the kernel.
729  *
730  *	This function assumes that struct video_device was zeroed when it
731  *	was allocated and does not contain any stale date.
732  *
733  *	An error is returned if no free minor or device node number could be
734  *	found, or if the registration of the device node failed.
735  *
736  *	Zero is returned on success.
737  *
738  *	Valid types are
739  *
740  *	%VFL_TYPE_GRABBER - A frame grabber
741  *
742  *	%VFL_TYPE_VBI - Vertical blank data (undecoded)
743  *
744  *	%VFL_TYPE_RADIO - A radio card
745  *
746  *	%VFL_TYPE_SUBDEV - A subdevice
747  *
748  *	%VFL_TYPE_SDR - Software Defined Radio
749  */
750 int __video_register_device(struct video_device *vdev, int type, int nr,
751 		int warn_if_nr_in_use, struct module *owner)
752 {
753 	int i = 0;
754 	int ret;
755 	int minor_offset = 0;
756 	int minor_cnt = VIDEO_NUM_DEVICES;
757 	const char *name_base;
758 
759 	/* A minor value of -1 marks this video device as never
760 	   having been registered */
761 	vdev->minor = -1;
762 
763 	/* the release callback MUST be present */
764 	if (WARN_ON(!vdev->release))
765 		return -EINVAL;
766 	/* the v4l2_dev pointer MUST be present */
767 	if (WARN_ON(!vdev->v4l2_dev))
768 		return -EINVAL;
769 
770 	/* v4l2_fh support */
771 	spin_lock_init(&vdev->fh_lock);
772 	INIT_LIST_HEAD(&vdev->fh_list);
773 
774 	/* Part 1: check device type */
775 	switch (type) {
776 	case VFL_TYPE_GRABBER:
777 		name_base = "video";
778 		break;
779 	case VFL_TYPE_VBI:
780 		name_base = "vbi";
781 		break;
782 	case VFL_TYPE_RADIO:
783 		name_base = "radio";
784 		break;
785 	case VFL_TYPE_SUBDEV:
786 		name_base = "v4l-subdev";
787 		break;
788 	case VFL_TYPE_SDR:
789 		/* Use device name 'swradio' because 'sdr' was already taken. */
790 		name_base = "swradio";
791 		break;
792 	default:
793 		printk(KERN_ERR "%s called with unknown type: %d\n",
794 		       __func__, type);
795 		return -EINVAL;
796 	}
797 
798 	vdev->vfl_type = type;
799 	vdev->cdev = NULL;
800 	if (vdev->dev_parent == NULL)
801 		vdev->dev_parent = vdev->v4l2_dev->dev;
802 	if (vdev->ctrl_handler == NULL)
803 		vdev->ctrl_handler = vdev->v4l2_dev->ctrl_handler;
804 	/* If the prio state pointer is NULL, then use the v4l2_device
805 	   prio state. */
806 	if (vdev->prio == NULL)
807 		vdev->prio = &vdev->v4l2_dev->prio;
808 
809 	/* Part 2: find a free minor, device node number and device index. */
810 #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
811 	/* Keep the ranges for the first four types for historical
812 	 * reasons.
813 	 * Newer devices (not yet in place) should use the range
814 	 * of 128-191 and just pick the first free minor there
815 	 * (new style). */
816 	switch (type) {
817 	case VFL_TYPE_GRABBER:
818 		minor_offset = 0;
819 		minor_cnt = 64;
820 		break;
821 	case VFL_TYPE_RADIO:
822 		minor_offset = 64;
823 		minor_cnt = 64;
824 		break;
825 	case VFL_TYPE_VBI:
826 		minor_offset = 224;
827 		minor_cnt = 32;
828 		break;
829 	default:
830 		minor_offset = 128;
831 		minor_cnt = 64;
832 		break;
833 	}
834 #endif
835 
836 	/* Pick a device node number */
837 	mutex_lock(&videodev_lock);
838 	nr = devnode_find(vdev, nr == -1 ? 0 : nr, minor_cnt);
839 	if (nr == minor_cnt)
840 		nr = devnode_find(vdev, 0, minor_cnt);
841 	if (nr == minor_cnt) {
842 		printk(KERN_ERR "could not get a free device node number\n");
843 		mutex_unlock(&videodev_lock);
844 		return -ENFILE;
845 	}
846 #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
847 	/* 1-on-1 mapping of device node number to minor number */
848 	i = nr;
849 #else
850 	/* The device node number and minor numbers are independent, so
851 	   we just find the first free minor number. */
852 	for (i = 0; i < VIDEO_NUM_DEVICES; i++)
853 		if (video_device[i] == NULL)
854 			break;
855 	if (i == VIDEO_NUM_DEVICES) {
856 		mutex_unlock(&videodev_lock);
857 		printk(KERN_ERR "could not get a free minor\n");
858 		return -ENFILE;
859 	}
860 #endif
861 	vdev->minor = i + minor_offset;
862 	vdev->num = nr;
863 	devnode_set(vdev);
864 
865 	/* Should not happen since we thought this minor was free */
866 	WARN_ON(video_device[vdev->minor] != NULL);
867 	vdev->index = get_index(vdev);
868 	video_device[vdev->minor] = vdev;
869 	mutex_unlock(&videodev_lock);
870 
871 	if (vdev->ioctl_ops)
872 		determine_valid_ioctls(vdev);
873 
874 	/* Part 3: Initialize the character device */
875 	vdev->cdev = cdev_alloc();
876 	if (vdev->cdev == NULL) {
877 		ret = -ENOMEM;
878 		goto cleanup;
879 	}
880 	vdev->cdev->ops = &v4l2_fops;
881 	vdev->cdev->owner = owner;
882 	ret = cdev_add(vdev->cdev, MKDEV(VIDEO_MAJOR, vdev->minor), 1);
883 	if (ret < 0) {
884 		printk(KERN_ERR "%s: cdev_add failed\n", __func__);
885 		kfree(vdev->cdev);
886 		vdev->cdev = NULL;
887 		goto cleanup;
888 	}
889 
890 	/* Part 4: register the device with sysfs */
891 	vdev->dev.class = &video_class;
892 	vdev->dev.devt = MKDEV(VIDEO_MAJOR, vdev->minor);
893 	vdev->dev.parent = vdev->dev_parent;
894 	dev_set_name(&vdev->dev, "%s%d", name_base, vdev->num);
895 	ret = device_register(&vdev->dev);
896 	if (ret < 0) {
897 		printk(KERN_ERR "%s: device_register failed\n", __func__);
898 		goto cleanup;
899 	}
900 	/* Register the release callback that will be called when the last
901 	   reference to the device goes away. */
902 	vdev->dev.release = v4l2_device_release;
903 
904 	if (nr != -1 && nr != vdev->num && warn_if_nr_in_use)
905 		printk(KERN_WARNING "%s: requested %s%d, got %s\n", __func__,
906 			name_base, nr, video_device_node_name(vdev));
907 
908 	/* Increase v4l2_device refcount */
909 	v4l2_device_get(vdev->v4l2_dev);
910 
911 #if defined(CONFIG_MEDIA_CONTROLLER)
912 	/* Part 5: Register the entity. */
913 	if (vdev->v4l2_dev->mdev &&
914 	    vdev->vfl_type != VFL_TYPE_SUBDEV) {
915 		vdev->entity.type = MEDIA_ENT_T_DEVNODE_V4L;
916 		vdev->entity.name = vdev->name;
917 		vdev->entity.info.dev.major = VIDEO_MAJOR;
918 		vdev->entity.info.dev.minor = vdev->minor;
919 		ret = media_device_register_entity(vdev->v4l2_dev->mdev,
920 			&vdev->entity);
921 		if (ret < 0)
922 			printk(KERN_WARNING
923 			       "%s: media_device_register_entity failed\n",
924 			       __func__);
925 	}
926 #endif
927 	/* Part 6: Activate this minor. The char device can now be used. */
928 	set_bit(V4L2_FL_REGISTERED, &vdev->flags);
929 
930 	return 0;
931 
932 cleanup:
933 	mutex_lock(&videodev_lock);
934 	if (vdev->cdev)
935 		cdev_del(vdev->cdev);
936 	video_device[vdev->minor] = NULL;
937 	devnode_clear(vdev);
938 	mutex_unlock(&videodev_lock);
939 	/* Mark this video device as never having been registered. */
940 	vdev->minor = -1;
941 	return ret;
942 }
943 EXPORT_SYMBOL(__video_register_device);
944 
945 /**
946  *	video_unregister_device - unregister a video4linux device
947  *	@vdev: the device to unregister
948  *
949  *	This unregisters the passed device. Future open calls will
950  *	be met with errors.
951  */
952 void video_unregister_device(struct video_device *vdev)
953 {
954 	/* Check if vdev was ever registered at all */
955 	if (!vdev || !video_is_registered(vdev))
956 		return;
957 
958 	mutex_lock(&videodev_lock);
959 	/* This must be in a critical section to prevent a race with v4l2_open.
960 	 * Once this bit has been cleared video_get may never be called again.
961 	 */
962 	clear_bit(V4L2_FL_REGISTERED, &vdev->flags);
963 	mutex_unlock(&videodev_lock);
964 	device_unregister(&vdev->dev);
965 }
966 EXPORT_SYMBOL(video_unregister_device);
967 
968 /*
969  *	Initialise video for linux
970  */
971 static int __init videodev_init(void)
972 {
973 	dev_t dev = MKDEV(VIDEO_MAJOR, 0);
974 	int ret;
975 
976 	printk(KERN_INFO "Linux video capture interface: v2.00\n");
977 	ret = register_chrdev_region(dev, VIDEO_NUM_DEVICES, VIDEO_NAME);
978 	if (ret < 0) {
979 		printk(KERN_WARNING "videodev: unable to get major %d\n",
980 				VIDEO_MAJOR);
981 		return ret;
982 	}
983 
984 	ret = class_register(&video_class);
985 	if (ret < 0) {
986 		unregister_chrdev_region(dev, VIDEO_NUM_DEVICES);
987 		printk(KERN_WARNING "video_dev: class_register failed\n");
988 		return -EIO;
989 	}
990 
991 	return 0;
992 }
993 
994 static void __exit videodev_exit(void)
995 {
996 	dev_t dev = MKDEV(VIDEO_MAJOR, 0);
997 
998 	class_unregister(&video_class);
999 	unregister_chrdev_region(dev, VIDEO_NUM_DEVICES);
1000 }
1001 
1002 subsys_initcall(videodev_init);
1003 module_exit(videodev_exit)
1004 
1005 MODULE_AUTHOR("Alan Cox, Mauro Carvalho Chehab <mchehab@infradead.org>");
1006 MODULE_DESCRIPTION("Device registrar for Video4Linux drivers v2");
1007 MODULE_LICENSE("GPL");
1008 MODULE_ALIAS_CHARDEV_MAJOR(VIDEO_MAJOR);
1009