2 * Video capture interface for Linux version 2
4 * A generic video device interface for the LINUX operating system
5 * using a set of device structures/vectors for low level operations.
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.
12 * Authors: Alan Cox, <alan@lxorguk.ukuu.org.uk> (version 1)
13 * Mauro Carvalho Chehab <mchehab@infradead.org> (version 2)
15 * Fixes: 20000516 Claudio Matsuoka <claudio@conectiva.com>
16 * - Added procfs support
19 #include <linux/module.h>
20 #include <linux/types.h>
21 #include <linux/kernel.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>
30 #include <media/v4l2-common.h>
31 #include <media/v4l2-device.h>
32 #include <media/v4l2-ioctl.h>
34 #define VIDEO_NUM_DEVICES 256
35 #define VIDEO_NAME "video4linux"
41 static ssize_t show_index(struct device *cd,
42 struct device_attribute *attr, char *buf)
44 struct video_device *vdev = to_video_device(cd);
46 return sprintf(buf, "%i\n", vdev->index);
49 static ssize_t show_name(struct device *cd,
50 struct device_attribute *attr, char *buf)
52 struct video_device *vdev = to_video_device(cd);
54 return sprintf(buf, "%.*s\n", (int)sizeof(vdev->name), vdev->name);
57 static struct device_attribute video_device_attrs[] = {
58 __ATTR(name, S_IRUGO, show_name, NULL),
59 __ATTR(index, S_IRUGO, show_index, NULL),
66 static struct video_device *video_device[VIDEO_NUM_DEVICES];
67 static DEFINE_MUTEX(videodev_lock);
68 static DECLARE_BITMAP(devnode_nums[VFL_TYPE_MAX], VIDEO_NUM_DEVICES);
70 /* Device node utility functions */
72 /* Note: these utility functions all assume that vfl_type is in the range
73 [0, VFL_TYPE_MAX-1]. */
75 #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
76 /* Return the bitmap corresponding to vfl_type. */
77 static inline unsigned long *devnode_bits(int vfl_type)
79 /* Any types not assigned to fixed minor ranges must be mapped to
80 one single bitmap for the purposes of finding a free node number
81 since all those unassigned types use the same minor range. */
82 int idx = (vfl_type > VFL_TYPE_RADIO) ? VFL_TYPE_MAX - 1 : vfl_type;
84 return devnode_nums[idx];
87 /* Return the bitmap corresponding to vfl_type. */
88 static inline unsigned long *devnode_bits(int vfl_type)
90 return devnode_nums[vfl_type];
94 /* Mark device node number vdev->num as used */
95 static inline void devnode_set(struct video_device *vdev)
97 set_bit(vdev->num, devnode_bits(vdev->vfl_type));
100 /* Mark device node number vdev->num as unused */
101 static inline void devnode_clear(struct video_device *vdev)
103 clear_bit(vdev->num, devnode_bits(vdev->vfl_type));
106 /* Try to find a free device node number in the range [from, to> */
107 static inline int devnode_find(struct video_device *vdev, int from, int to)
109 return find_next_zero_bit(devnode_bits(vdev->vfl_type), to, from);
112 struct video_device *video_device_alloc(void)
114 return kzalloc(sizeof(struct video_device), GFP_KERNEL);
116 EXPORT_SYMBOL(video_device_alloc);
118 void video_device_release(struct video_device *vdev)
122 EXPORT_SYMBOL(video_device_release);
124 void video_device_release_empty(struct video_device *vdev)
127 /* Only valid when the video_device struct is a static. */
129 EXPORT_SYMBOL(video_device_release_empty);
131 static inline void video_get(struct video_device *vdev)
133 get_device(&vdev->dev);
136 static inline void video_put(struct video_device *vdev)
138 put_device(&vdev->dev);
141 /* Called when the last user of the video device exits. */
142 static void v4l2_device_release(struct device *cd)
144 struct video_device *vdev = to_video_device(cd);
145 struct v4l2_device *v4l2_dev = vdev->v4l2_dev;
147 mutex_lock(&videodev_lock);
148 if (WARN_ON(video_device[vdev->minor] != vdev)) {
149 /* should not happen */
150 mutex_unlock(&videodev_lock);
154 /* Free up this device for reuse */
155 video_device[vdev->minor] = NULL;
157 /* Delete the cdev on this minor as well */
158 cdev_del(vdev->cdev);
159 /* Just in case some driver tries to access this from
160 the release() callback. */
163 /* Mark device node number as free */
166 mutex_unlock(&videodev_lock);
168 #if defined(CONFIG_MEDIA_CONTROLLER)
169 if (v4l2_dev && v4l2_dev->mdev &&
170 vdev->vfl_type != VFL_TYPE_SUBDEV)
171 media_device_unregister_entity(&vdev->entity);
174 /* Do not call v4l2_device_put if there is no release callback set.
175 * Drivers that have no v4l2_device release callback might free the
176 * v4l2_dev instance in the video_device release callback below, so we
177 * must perform this check here.
179 * TODO: In the long run all drivers that use v4l2_device should use the
180 * v4l2_device release callback. This check will then be unnecessary.
182 if (v4l2_dev && v4l2_dev->release == NULL)
185 /* Release video_device and perform other
186 cleanups as needed. */
189 /* Decrease v4l2_device refcount */
191 v4l2_device_put(v4l2_dev);
194 static struct class video_class = {
196 .dev_attrs = video_device_attrs,
199 struct video_device *video_devdata(struct file *file)
201 return video_device[iminor(file->f_path.dentry->d_inode)];
203 EXPORT_SYMBOL(video_devdata);
206 /* Priority handling */
208 static inline bool prio_is_valid(enum v4l2_priority prio)
210 return prio == V4L2_PRIORITY_BACKGROUND ||
211 prio == V4L2_PRIORITY_INTERACTIVE ||
212 prio == V4L2_PRIORITY_RECORD;
215 void v4l2_prio_init(struct v4l2_prio_state *global)
217 memset(global, 0, sizeof(*global));
219 EXPORT_SYMBOL(v4l2_prio_init);
221 int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
222 enum v4l2_priority new)
224 if (!prio_is_valid(new))
229 atomic_inc(&global->prios[new]);
230 if (prio_is_valid(*local))
231 atomic_dec(&global->prios[*local]);
235 EXPORT_SYMBOL(v4l2_prio_change);
237 void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local)
239 v4l2_prio_change(global, local, V4L2_PRIORITY_DEFAULT);
241 EXPORT_SYMBOL(v4l2_prio_open);
243 void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local)
245 if (prio_is_valid(local))
246 atomic_dec(&global->prios[local]);
248 EXPORT_SYMBOL(v4l2_prio_close);
250 enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global)
252 if (atomic_read(&global->prios[V4L2_PRIORITY_RECORD]) > 0)
253 return V4L2_PRIORITY_RECORD;
254 if (atomic_read(&global->prios[V4L2_PRIORITY_INTERACTIVE]) > 0)
255 return V4L2_PRIORITY_INTERACTIVE;
256 if (atomic_read(&global->prios[V4L2_PRIORITY_BACKGROUND]) > 0)
257 return V4L2_PRIORITY_BACKGROUND;
258 return V4L2_PRIORITY_UNSET;
260 EXPORT_SYMBOL(v4l2_prio_max);
262 int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local)
264 return (local < v4l2_prio_max(global)) ? -EBUSY : 0;
266 EXPORT_SYMBOL(v4l2_prio_check);
269 static ssize_t v4l2_read(struct file *filp, char __user *buf,
270 size_t sz, loff_t *off)
272 struct video_device *vdev = video_devdata(filp);
275 if (!vdev->fops->read)
277 if (vdev->lock && mutex_lock_interruptible(vdev->lock))
279 if (video_is_registered(vdev))
280 ret = vdev->fops->read(filp, buf, sz, off);
282 mutex_unlock(vdev->lock);
286 static ssize_t v4l2_write(struct file *filp, const char __user *buf,
287 size_t sz, loff_t *off)
289 struct video_device *vdev = video_devdata(filp);
292 if (!vdev->fops->write)
294 if (vdev->lock && mutex_lock_interruptible(vdev->lock))
296 if (video_is_registered(vdev))
297 ret = vdev->fops->write(filp, buf, sz, off);
299 mutex_unlock(vdev->lock);
303 static unsigned int v4l2_poll(struct file *filp, struct poll_table_struct *poll)
305 struct video_device *vdev = video_devdata(filp);
306 int ret = POLLERR | POLLHUP;
308 if (!vdev->fops->poll)
309 return DEFAULT_POLLMASK;
311 mutex_lock(vdev->lock);
312 if (video_is_registered(vdev))
313 ret = vdev->fops->poll(filp, poll);
315 mutex_unlock(vdev->lock);
319 static long v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
321 struct video_device *vdev = video_devdata(filp);
324 if (vdev->fops->unlocked_ioctl) {
328 /* always lock unless the cmd is marked as "don't use lock" */
329 locked = !v4l2_is_known_ioctl(cmd) ||
330 !test_bit(_IOC_NR(cmd), vdev->dont_use_lock);
332 if (locked && mutex_lock_interruptible(vdev->lock))
335 if (video_is_registered(vdev))
336 ret = vdev->fops->unlocked_ioctl(filp, cmd, arg);
338 mutex_unlock(vdev->lock);
339 } else if (vdev->fops->ioctl) {
340 /* This code path is a replacement for the BKL. It is a major
341 * hack but it will have to do for those drivers that are not
342 * yet converted to use unlocked_ioctl.
344 * There are two options: if the driver implements struct
345 * v4l2_device, then the lock defined there is used to
346 * serialize the ioctls. Otherwise the v4l2 core lock defined
347 * below is used. This lock is really bad since it serializes
348 * completely independent devices.
350 * Both variants suffer from the same problem: if the driver
351 * sleeps, then it blocks all ioctls since the lock is still
352 * held. This is very common for VIDIOC_DQBUF since that
353 * normally waits for a frame to arrive. As a result any other
354 * ioctl calls will proceed very, very slowly since each call
355 * will have to wait for the VIDIOC_QBUF to finish. Things that
356 * should take 0.01s may now take 10-20 seconds.
358 * The workaround is to *not* take the lock for VIDIOC_DQBUF.
359 * This actually works OK for videobuf-based drivers, since
360 * videobuf will take its own internal lock.
362 static DEFINE_MUTEX(v4l2_ioctl_mutex);
363 struct mutex *m = vdev->v4l2_dev ?
364 &vdev->v4l2_dev->ioctl_lock : &v4l2_ioctl_mutex;
366 if (cmd != VIDIOC_DQBUF && mutex_lock_interruptible(m))
368 if (video_is_registered(vdev))
369 ret = vdev->fops->ioctl(filp, cmd, arg);
370 if (cmd != VIDIOC_DQBUF)
379 #define v4l2_get_unmapped_area NULL
381 static unsigned long v4l2_get_unmapped_area(struct file *filp,
382 unsigned long addr, unsigned long len, unsigned long pgoff,
385 struct video_device *vdev = video_devdata(filp);
387 if (!vdev->fops->get_unmapped_area)
389 if (!video_is_registered(vdev))
391 return vdev->fops->get_unmapped_area(filp, addr, len, pgoff, flags);
395 static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm)
397 struct video_device *vdev = video_devdata(filp);
400 if (!vdev->fops->mmap)
402 if (vdev->lock && mutex_lock_interruptible(vdev->lock))
404 if (video_is_registered(vdev))
405 ret = vdev->fops->mmap(filp, vm);
407 mutex_unlock(vdev->lock);
411 /* Override for the open function */
412 static int v4l2_open(struct inode *inode, struct file *filp)
414 struct video_device *vdev;
417 /* Check if the video device is available */
418 mutex_lock(&videodev_lock);
419 vdev = video_devdata(filp);
420 /* return ENODEV if the video device has already been removed. */
421 if (vdev == NULL || !video_is_registered(vdev)) {
422 mutex_unlock(&videodev_lock);
425 /* and increase the device refcount */
427 mutex_unlock(&videodev_lock);
428 if (vdev->fops->open) {
429 if (vdev->lock && mutex_lock_interruptible(vdev->lock)) {
433 if (video_is_registered(vdev))
434 ret = vdev->fops->open(filp);
438 mutex_unlock(vdev->lock);
442 /* decrease the refcount in case of an error */
448 /* Override for the release function */
449 static int v4l2_release(struct inode *inode, struct file *filp)
451 struct video_device *vdev = video_devdata(filp);
454 if (vdev->fops->release) {
456 mutex_lock(vdev->lock);
457 vdev->fops->release(filp);
459 mutex_unlock(vdev->lock);
461 /* decrease the refcount unconditionally since the release()
462 return value is ignored. */
467 static const struct file_operations v4l2_fops = {
468 .owner = THIS_MODULE,
472 .get_unmapped_area = v4l2_get_unmapped_area,
474 .unlocked_ioctl = v4l2_ioctl,
476 .compat_ioctl = v4l2_compat_ioctl32,
478 .release = v4l2_release,
484 * get_index - assign stream index number based on parent device
485 * @vdev: video_device to assign index number to, vdev->parent should be assigned
487 * Note that when this is called the new device has not yet been registered
488 * in the video_device array, but it was able to obtain a minor number.
490 * This means that we can always obtain a free stream index number since
491 * the worst case scenario is that there are VIDEO_NUM_DEVICES - 1 slots in
492 * use of the video_device array.
494 * Returns a free index number.
496 static int get_index(struct video_device *vdev)
498 /* This can be static since this function is called with the global
499 videodev_lock held. */
500 static DECLARE_BITMAP(used, VIDEO_NUM_DEVICES);
503 /* Some drivers do not set the parent. In that case always return 0. */
504 if (vdev->parent == NULL)
507 bitmap_zero(used, VIDEO_NUM_DEVICES);
509 for (i = 0; i < VIDEO_NUM_DEVICES; i++) {
510 if (video_device[i] != NULL &&
511 video_device[i]->parent == vdev->parent) {
512 set_bit(video_device[i]->index, used);
516 return find_first_zero_bit(used, VIDEO_NUM_DEVICES);
519 #define SET_VALID_IOCTL(ops, cmd, op) \
521 set_bit(_IOC_NR(cmd), valid_ioctls)
523 /* This determines which ioctls are actually implemented in the driver.
524 It's a one-time thing which simplifies video_ioctl2 as it can just do
527 Note that drivers can override this by setting bits to 1 in
528 vdev->valid_ioctls. If an ioctl is marked as 1 when this function is
529 called, then that ioctl will actually be marked as unimplemented.
531 It does that by first setting up the local valid_ioctls bitmap, and
534 vdev->valid_ioctls = valid_ioctls & ~(vdev->valid_ioctls)
536 static void determine_valid_ioctls(struct video_device *vdev)
538 DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);
539 const struct v4l2_ioctl_ops *ops = vdev->ioctl_ops;
541 bitmap_zero(valid_ioctls, BASE_VIDIOC_PRIVATE);
543 SET_VALID_IOCTL(ops, VIDIOC_QUERYCAP, vidioc_querycap);
544 if (ops->vidioc_g_priority ||
545 test_bit(V4L2_FL_USE_FH_PRIO, &vdev->flags))
546 set_bit(_IOC_NR(VIDIOC_G_PRIORITY), valid_ioctls);
547 if (ops->vidioc_s_priority ||
548 test_bit(V4L2_FL_USE_FH_PRIO, &vdev->flags))
549 set_bit(_IOC_NR(VIDIOC_S_PRIORITY), valid_ioctls);
550 if (ops->vidioc_enum_fmt_vid_cap ||
551 ops->vidioc_enum_fmt_vid_out ||
552 ops->vidioc_enum_fmt_vid_cap_mplane ||
553 ops->vidioc_enum_fmt_vid_out_mplane ||
554 ops->vidioc_enum_fmt_vid_overlay ||
555 ops->vidioc_enum_fmt_type_private)
556 set_bit(_IOC_NR(VIDIOC_ENUM_FMT), valid_ioctls);
557 if (ops->vidioc_g_fmt_vid_cap ||
558 ops->vidioc_g_fmt_vid_out ||
559 ops->vidioc_g_fmt_vid_cap_mplane ||
560 ops->vidioc_g_fmt_vid_out_mplane ||
561 ops->vidioc_g_fmt_vid_overlay ||
562 ops->vidioc_g_fmt_vbi_cap ||
563 ops->vidioc_g_fmt_vid_out_overlay ||
564 ops->vidioc_g_fmt_vbi_out ||
565 ops->vidioc_g_fmt_sliced_vbi_cap ||
566 ops->vidioc_g_fmt_sliced_vbi_out ||
567 ops->vidioc_g_fmt_type_private)
568 set_bit(_IOC_NR(VIDIOC_G_FMT), valid_ioctls);
569 if (ops->vidioc_s_fmt_vid_cap ||
570 ops->vidioc_s_fmt_vid_out ||
571 ops->vidioc_s_fmt_vid_cap_mplane ||
572 ops->vidioc_s_fmt_vid_out_mplane ||
573 ops->vidioc_s_fmt_vid_overlay ||
574 ops->vidioc_s_fmt_vbi_cap ||
575 ops->vidioc_s_fmt_vid_out_overlay ||
576 ops->vidioc_s_fmt_vbi_out ||
577 ops->vidioc_s_fmt_sliced_vbi_cap ||
578 ops->vidioc_s_fmt_sliced_vbi_out ||
579 ops->vidioc_s_fmt_type_private)
580 set_bit(_IOC_NR(VIDIOC_S_FMT), valid_ioctls);
581 if (ops->vidioc_try_fmt_vid_cap ||
582 ops->vidioc_try_fmt_vid_out ||
583 ops->vidioc_try_fmt_vid_cap_mplane ||
584 ops->vidioc_try_fmt_vid_out_mplane ||
585 ops->vidioc_try_fmt_vid_overlay ||
586 ops->vidioc_try_fmt_vbi_cap ||
587 ops->vidioc_try_fmt_vid_out_overlay ||
588 ops->vidioc_try_fmt_vbi_out ||
589 ops->vidioc_try_fmt_sliced_vbi_cap ||
590 ops->vidioc_try_fmt_sliced_vbi_out ||
591 ops->vidioc_try_fmt_type_private)
592 set_bit(_IOC_NR(VIDIOC_TRY_FMT), valid_ioctls);
593 SET_VALID_IOCTL(ops, VIDIOC_REQBUFS, vidioc_reqbufs);
594 SET_VALID_IOCTL(ops, VIDIOC_QUERYBUF, vidioc_querybuf);
595 SET_VALID_IOCTL(ops, VIDIOC_QBUF, vidioc_qbuf);
596 SET_VALID_IOCTL(ops, VIDIOC_EXPBUF, vidioc_expbuf);
597 SET_VALID_IOCTL(ops, VIDIOC_DQBUF, vidioc_dqbuf);
598 SET_VALID_IOCTL(ops, VIDIOC_OVERLAY, vidioc_overlay);
599 SET_VALID_IOCTL(ops, VIDIOC_G_FBUF, vidioc_g_fbuf);
600 SET_VALID_IOCTL(ops, VIDIOC_S_FBUF, vidioc_s_fbuf);
601 SET_VALID_IOCTL(ops, VIDIOC_STREAMON, vidioc_streamon);
602 SET_VALID_IOCTL(ops, VIDIOC_STREAMOFF, vidioc_streamoff);
604 set_bit(_IOC_NR(VIDIOC_ENUMSTD), valid_ioctls);
605 if (ops->vidioc_g_std || vdev->current_norm)
606 set_bit(_IOC_NR(VIDIOC_G_STD), valid_ioctls);
607 SET_VALID_IOCTL(ops, VIDIOC_S_STD, vidioc_s_std);
608 SET_VALID_IOCTL(ops, VIDIOC_QUERYSTD, vidioc_querystd);
609 SET_VALID_IOCTL(ops, VIDIOC_ENUMINPUT, vidioc_enum_input);
610 SET_VALID_IOCTL(ops, VIDIOC_G_INPUT, vidioc_g_input);
611 SET_VALID_IOCTL(ops, VIDIOC_S_INPUT, vidioc_s_input);
612 SET_VALID_IOCTL(ops, VIDIOC_ENUMOUTPUT, vidioc_enum_output);
613 SET_VALID_IOCTL(ops, VIDIOC_G_OUTPUT, vidioc_g_output);
614 SET_VALID_IOCTL(ops, VIDIOC_S_OUTPUT, vidioc_s_output);
615 /* Note: the control handler can also be passed through the filehandle,
616 and that can't be tested here. If the bit for these control ioctls
617 is set, then the ioctl is valid. But if it is 0, then it can still
618 be valid if the filehandle passed the control handler. */
619 if (vdev->ctrl_handler || ops->vidioc_queryctrl)
620 set_bit(_IOC_NR(VIDIOC_QUERYCTRL), valid_ioctls);
621 if (vdev->ctrl_handler || ops->vidioc_g_ctrl || ops->vidioc_g_ext_ctrls)
622 set_bit(_IOC_NR(VIDIOC_G_CTRL), valid_ioctls);
623 if (vdev->ctrl_handler || ops->vidioc_s_ctrl || ops->vidioc_s_ext_ctrls)
624 set_bit(_IOC_NR(VIDIOC_S_CTRL), valid_ioctls);
625 if (vdev->ctrl_handler || ops->vidioc_g_ext_ctrls)
626 set_bit(_IOC_NR(VIDIOC_G_EXT_CTRLS), valid_ioctls);
627 if (vdev->ctrl_handler || ops->vidioc_s_ext_ctrls)
628 set_bit(_IOC_NR(VIDIOC_S_EXT_CTRLS), valid_ioctls);
629 if (vdev->ctrl_handler || ops->vidioc_try_ext_ctrls)
630 set_bit(_IOC_NR(VIDIOC_TRY_EXT_CTRLS), valid_ioctls);
631 if (vdev->ctrl_handler || ops->vidioc_querymenu)
632 set_bit(_IOC_NR(VIDIOC_QUERYMENU), valid_ioctls);
633 SET_VALID_IOCTL(ops, VIDIOC_ENUMAUDIO, vidioc_enumaudio);
634 SET_VALID_IOCTL(ops, VIDIOC_G_AUDIO, vidioc_g_audio);
635 SET_VALID_IOCTL(ops, VIDIOC_S_AUDIO, vidioc_s_audio);
636 SET_VALID_IOCTL(ops, VIDIOC_ENUMAUDOUT, vidioc_enumaudout);
637 SET_VALID_IOCTL(ops, VIDIOC_G_AUDOUT, vidioc_g_audout);
638 SET_VALID_IOCTL(ops, VIDIOC_S_AUDOUT, vidioc_s_audout);
639 SET_VALID_IOCTL(ops, VIDIOC_G_MODULATOR, vidioc_g_modulator);
640 SET_VALID_IOCTL(ops, VIDIOC_S_MODULATOR, vidioc_s_modulator);
641 if (ops->vidioc_g_crop || ops->vidioc_g_selection)
642 set_bit(_IOC_NR(VIDIOC_G_CROP), valid_ioctls);
643 if (ops->vidioc_s_crop || ops->vidioc_s_selection)
644 set_bit(_IOC_NR(VIDIOC_S_CROP), valid_ioctls);
645 SET_VALID_IOCTL(ops, VIDIOC_G_SELECTION, vidioc_g_selection);
646 SET_VALID_IOCTL(ops, VIDIOC_S_SELECTION, vidioc_s_selection);
647 if (ops->vidioc_cropcap || ops->vidioc_g_selection)
648 set_bit(_IOC_NR(VIDIOC_CROPCAP), valid_ioctls);
649 SET_VALID_IOCTL(ops, VIDIOC_G_JPEGCOMP, vidioc_g_jpegcomp);
650 SET_VALID_IOCTL(ops, VIDIOC_S_JPEGCOMP, vidioc_s_jpegcomp);
651 SET_VALID_IOCTL(ops, VIDIOC_G_ENC_INDEX, vidioc_g_enc_index);
652 SET_VALID_IOCTL(ops, VIDIOC_ENCODER_CMD, vidioc_encoder_cmd);
653 SET_VALID_IOCTL(ops, VIDIOC_TRY_ENCODER_CMD, vidioc_try_encoder_cmd);
654 SET_VALID_IOCTL(ops, VIDIOC_DECODER_CMD, vidioc_decoder_cmd);
655 SET_VALID_IOCTL(ops, VIDIOC_TRY_DECODER_CMD, vidioc_try_decoder_cmd);
656 if (ops->vidioc_g_parm || vdev->current_norm)
657 set_bit(_IOC_NR(VIDIOC_G_PARM), valid_ioctls);
658 SET_VALID_IOCTL(ops, VIDIOC_S_PARM, vidioc_s_parm);
659 SET_VALID_IOCTL(ops, VIDIOC_G_TUNER, vidioc_g_tuner);
660 SET_VALID_IOCTL(ops, VIDIOC_S_TUNER, vidioc_s_tuner);
661 SET_VALID_IOCTL(ops, VIDIOC_G_FREQUENCY, vidioc_g_frequency);
662 SET_VALID_IOCTL(ops, VIDIOC_S_FREQUENCY, vidioc_s_frequency);
663 SET_VALID_IOCTL(ops, VIDIOC_G_SLICED_VBI_CAP, vidioc_g_sliced_vbi_cap);
664 SET_VALID_IOCTL(ops, VIDIOC_LOG_STATUS, vidioc_log_status);
665 #ifdef CONFIG_VIDEO_ADV_DEBUG
666 SET_VALID_IOCTL(ops, VIDIOC_DBG_G_REGISTER, vidioc_g_register);
667 SET_VALID_IOCTL(ops, VIDIOC_DBG_S_REGISTER, vidioc_s_register);
669 SET_VALID_IOCTL(ops, VIDIOC_DBG_G_CHIP_IDENT, vidioc_g_chip_ident);
670 SET_VALID_IOCTL(ops, VIDIOC_S_HW_FREQ_SEEK, vidioc_s_hw_freq_seek);
671 SET_VALID_IOCTL(ops, VIDIOC_ENUM_FRAMESIZES, vidioc_enum_framesizes);
672 SET_VALID_IOCTL(ops, VIDIOC_ENUM_FRAMEINTERVALS, vidioc_enum_frameintervals);
673 SET_VALID_IOCTL(ops, VIDIOC_ENUM_DV_PRESETS, vidioc_enum_dv_presets);
674 SET_VALID_IOCTL(ops, VIDIOC_S_DV_PRESET, vidioc_s_dv_preset);
675 SET_VALID_IOCTL(ops, VIDIOC_G_DV_PRESET, vidioc_g_dv_preset);
676 SET_VALID_IOCTL(ops, VIDIOC_QUERY_DV_PRESET, vidioc_query_dv_preset);
677 SET_VALID_IOCTL(ops, VIDIOC_S_DV_TIMINGS, vidioc_s_dv_timings);
678 SET_VALID_IOCTL(ops, VIDIOC_G_DV_TIMINGS, vidioc_g_dv_timings);
679 /* yes, really vidioc_subscribe_event */
680 SET_VALID_IOCTL(ops, VIDIOC_DQEVENT, vidioc_subscribe_event);
681 SET_VALID_IOCTL(ops, VIDIOC_SUBSCRIBE_EVENT, vidioc_subscribe_event);
682 SET_VALID_IOCTL(ops, VIDIOC_UNSUBSCRIBE_EVENT, vidioc_unsubscribe_event);
683 SET_VALID_IOCTL(ops, VIDIOC_CREATE_BUFS, vidioc_create_bufs);
684 SET_VALID_IOCTL(ops, VIDIOC_PREPARE_BUF, vidioc_prepare_buf);
685 bitmap_andnot(vdev->valid_ioctls, valid_ioctls, vdev->valid_ioctls,
686 BASE_VIDIOC_PRIVATE);
690 * __video_register_device - register video4linux devices
691 * @vdev: video device structure we want to register
692 * @type: type of device to register
693 * @nr: which device node number (0 == /dev/video0, 1 == /dev/video1, ...
695 * @warn_if_nr_in_use: warn if the desired device node number
696 * was already in use and another number was chosen instead.
697 * @owner: module that owns the video device node
699 * The registration code assigns minor numbers and device node numbers
700 * based on the requested type and registers the new device node with
703 * This function assumes that struct video_device was zeroed when it
704 * was allocated and does not contain any stale date.
706 * An error is returned if no free minor or device node number could be
707 * found, or if the registration of the device node failed.
709 * Zero is returned on success.
713 * %VFL_TYPE_GRABBER - A frame grabber
715 * %VFL_TYPE_VBI - Vertical blank data (undecoded)
717 * %VFL_TYPE_RADIO - A radio card
719 * %VFL_TYPE_SUBDEV - A subdevice
721 int __video_register_device(struct video_device *vdev, int type, int nr,
722 int warn_if_nr_in_use, struct module *owner)
726 int minor_offset = 0;
727 int minor_cnt = VIDEO_NUM_DEVICES;
728 const char *name_base;
730 /* A minor value of -1 marks this video device as never
731 having been registered */
734 /* the release callback MUST be present */
735 if (WARN_ON(!vdev->release))
738 /* v4l2_fh support */
739 spin_lock_init(&vdev->fh_lock);
740 INIT_LIST_HEAD(&vdev->fh_list);
742 /* Part 1: check device type */
744 case VFL_TYPE_GRABBER:
753 case VFL_TYPE_SUBDEV:
754 name_base = "v4l-subdev";
757 printk(KERN_ERR "%s called with unknown type: %d\n",
762 vdev->vfl_type = type;
764 if (vdev->v4l2_dev) {
765 if (vdev->v4l2_dev->dev)
766 vdev->parent = vdev->v4l2_dev->dev;
767 if (vdev->ctrl_handler == NULL)
768 vdev->ctrl_handler = vdev->v4l2_dev->ctrl_handler;
769 /* If the prio state pointer is NULL, then use the v4l2_device
771 if (vdev->prio == NULL)
772 vdev->prio = &vdev->v4l2_dev->prio;
775 /* Part 2: find a free minor, device node number and device index. */
776 #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
777 /* Keep the ranges for the first four types for historical
779 * Newer devices (not yet in place) should use the range
780 * of 128-191 and just pick the first free minor there
783 case VFL_TYPE_GRABBER:
802 /* Pick a device node number */
803 mutex_lock(&videodev_lock);
804 nr = devnode_find(vdev, nr == -1 ? 0 : nr, minor_cnt);
806 nr = devnode_find(vdev, 0, minor_cnt);
807 if (nr == minor_cnt) {
808 printk(KERN_ERR "could not get a free device node number\n");
809 mutex_unlock(&videodev_lock);
812 #ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
813 /* 1-on-1 mapping of device node number to minor number */
816 /* The device node number and minor numbers are independent, so
817 we just find the first free minor number. */
818 for (i = 0; i < VIDEO_NUM_DEVICES; i++)
819 if (video_device[i] == NULL)
821 if (i == VIDEO_NUM_DEVICES) {
822 mutex_unlock(&videodev_lock);
823 printk(KERN_ERR "could not get a free minor\n");
827 vdev->minor = i + minor_offset;
831 /* Should not happen since we thought this minor was free */
832 WARN_ON(video_device[vdev->minor] != NULL);
833 vdev->index = get_index(vdev);
834 mutex_unlock(&videodev_lock);
837 determine_valid_ioctls(vdev);
839 /* Part 3: Initialize the character device */
840 vdev->cdev = cdev_alloc();
841 if (vdev->cdev == NULL) {
845 vdev->cdev->ops = &v4l2_fops;
846 vdev->cdev->owner = owner;
847 ret = cdev_add(vdev->cdev, MKDEV(VIDEO_MAJOR, vdev->minor), 1);
849 printk(KERN_ERR "%s: cdev_add failed\n", __func__);
855 /* Part 4: register the device with sysfs */
856 vdev->dev.class = &video_class;
857 vdev->dev.devt = MKDEV(VIDEO_MAJOR, vdev->minor);
859 vdev->dev.parent = vdev->parent;
860 dev_set_name(&vdev->dev, "%s%d", name_base, vdev->num);
861 ret = device_register(&vdev->dev);
863 printk(KERN_ERR "%s: device_register failed\n", __func__);
866 /* Register the release callback that will be called when the last
867 reference to the device goes away. */
868 vdev->dev.release = v4l2_device_release;
870 if (nr != -1 && nr != vdev->num && warn_if_nr_in_use)
871 printk(KERN_WARNING "%s: requested %s%d, got %s\n", __func__,
872 name_base, nr, video_device_node_name(vdev));
874 /* Increase v4l2_device refcount */
876 v4l2_device_get(vdev->v4l2_dev);
878 #if defined(CONFIG_MEDIA_CONTROLLER)
879 /* Part 5: Register the entity. */
880 if (vdev->v4l2_dev && vdev->v4l2_dev->mdev &&
881 vdev->vfl_type != VFL_TYPE_SUBDEV) {
882 vdev->entity.type = MEDIA_ENT_T_DEVNODE_V4L;
883 vdev->entity.name = vdev->name;
884 vdev->entity.info.v4l.major = VIDEO_MAJOR;
885 vdev->entity.info.v4l.minor = vdev->minor;
886 ret = media_device_register_entity(vdev->v4l2_dev->mdev,
890 "%s: media_device_register_entity failed\n",
894 /* Part 6: Activate this minor. The char device can now be used. */
895 set_bit(V4L2_FL_REGISTERED, &vdev->flags);
896 mutex_lock(&videodev_lock);
897 video_device[vdev->minor] = vdev;
898 mutex_unlock(&videodev_lock);
903 mutex_lock(&videodev_lock);
905 cdev_del(vdev->cdev);
907 mutex_unlock(&videodev_lock);
908 /* Mark this video device as never having been registered. */
912 EXPORT_SYMBOL(__video_register_device);
915 * video_unregister_device - unregister a video4linux device
916 * @vdev: the device to unregister
918 * This unregisters the passed device. Future open calls will
919 * be met with errors.
921 void video_unregister_device(struct video_device *vdev)
923 /* Check if vdev was ever registered at all */
924 if (!vdev || !video_is_registered(vdev))
927 mutex_lock(&videodev_lock);
928 /* This must be in a critical section to prevent a race with v4l2_open.
929 * Once this bit has been cleared video_get may never be called again.
931 clear_bit(V4L2_FL_REGISTERED, &vdev->flags);
932 mutex_unlock(&videodev_lock);
933 device_unregister(&vdev->dev);
935 EXPORT_SYMBOL(video_unregister_device);
938 * Initialise video for linux
940 static int __init videodev_init(void)
942 dev_t dev = MKDEV(VIDEO_MAJOR, 0);
945 printk(KERN_INFO "Linux video capture interface: v2.00\n");
946 ret = register_chrdev_region(dev, VIDEO_NUM_DEVICES, VIDEO_NAME);
948 printk(KERN_WARNING "videodev: unable to get major %d\n",
953 ret = class_register(&video_class);
955 unregister_chrdev_region(dev, VIDEO_NUM_DEVICES);
956 printk(KERN_WARNING "video_dev: class_register failed\n");
963 static void __exit videodev_exit(void)
965 dev_t dev = MKDEV(VIDEO_MAJOR, 0);
967 class_unregister(&video_class);
968 unregister_chrdev_region(dev, VIDEO_NUM_DEVICES);
971 subsys_initcall(videodev_init);
972 module_exit(videodev_exit)
974 MODULE_AUTHOR("Alan Cox, Mauro Carvalho Chehab <mchehab@infradead.org>");
975 MODULE_DESCRIPTION("Device registrar for Video4Linux drivers v2");
976 MODULE_LICENSE("GPL");
977 MODULE_ALIAS_CHARDEV_MAJOR(VIDEO_MAJOR);