blob: d72156517726a6dbcecde87796a5cd15bebd1bf4 [file] [log] [blame]
Hans Verkuil27a5e6d2008-07-20 08:43:17 -03001/*
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 *
Alan Coxd9b01442008-10-27 15:13:47 -030012 * Authors: Alan Cox, <alan@lxorguk.ukuu.org.uk> (version 1)
Hans Verkuil27a5e6d2008-07-20 08:43:17 -030013 * 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>
Hans Verkuil27a5e6d2008-07-20 08:43:17 -030028#include <asm/uaccess.h>
29#include <asm/system.h>
30
31#include <media/v4l2-common.h>
Hans Verkuil9bea3512008-12-23 07:35:17 -030032#include <media/v4l2-device.h>
Hans Verkuilbec43662008-12-30 06:58:20 -030033#include <media/v4l2-ioctl.h>
Hans Verkuil27a5e6d2008-07-20 08:43:17 -030034
35#define VIDEO_NUM_DEVICES 256
36#define VIDEO_NAME "video4linux"
37
38/*
39 * sysfs stuff
40 */
41
42static ssize_t show_index(struct device *cd,
43 struct device_attribute *attr, char *buf)
44{
Hans Verkuildc93a702008-12-19 21:28:27 -030045 struct video_device *vdev = to_video_device(cd);
Hans Verkuilbfa8a272008-08-23 07:48:38 -030046
Hans Verkuildc93a702008-12-19 21:28:27 -030047 return sprintf(buf, "%i\n", vdev->index);
Hans Verkuil27a5e6d2008-07-20 08:43:17 -030048}
49
50static ssize_t show_name(struct device *cd,
51 struct device_attribute *attr, char *buf)
52{
Hans Verkuildc93a702008-12-19 21:28:27 -030053 struct video_device *vdev = to_video_device(cd);
Hans Verkuilbfa8a272008-08-23 07:48:38 -030054
Hans Verkuildc93a702008-12-19 21:28:27 -030055 return sprintf(buf, "%.*s\n", (int)sizeof(vdev->name), vdev->name);
Hans Verkuil27a5e6d2008-07-20 08:43:17 -030056}
57
58static struct device_attribute video_device_attrs[] = {
59 __ATTR(name, S_IRUGO, show_name, NULL),
60 __ATTR(index, S_IRUGO, show_index, NULL),
61 __ATTR_NULL
62};
63
Hans Verkuil7f8ecfa2008-08-29 17:31:35 -030064/*
65 * Active devices
66 */
67static struct video_device *video_device[VIDEO_NUM_DEVICES];
68static DEFINE_MUTEX(videodev_lock);
Hans Verkuil22e22122009-09-06 07:13:14 -030069static DECLARE_BITMAP(devnode_nums[VFL_TYPE_MAX], VIDEO_NUM_DEVICES);
Hans Verkuil7f8ecfa2008-08-29 17:31:35 -030070
Hans Verkuil5062cb72009-09-07 03:40:24 -030071/* Device node utility functions */
72
73/* Note: these utility functions all assume that vfl_type is in the range
74 [0, VFL_TYPE_MAX-1]. */
75
76#ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
77/* Return the bitmap corresponding to vfl_type. */
78static inline unsigned long *devnode_bits(int vfl_type)
79{
80 /* Any types not assigned to fixed minor ranges must be mapped to
81 one single bitmap for the purposes of finding a free node number
82 since all those unassigned types use the same minor range. */
Hans Verkuil226c0ee2010-08-06 12:48:00 -030083 int idx = (vfl_type > VFL_TYPE_RADIO) ? VFL_TYPE_MAX - 1 : vfl_type;
Hans Verkuil5062cb72009-09-07 03:40:24 -030084
85 return devnode_nums[idx];
86}
87#else
88/* Return the bitmap corresponding to vfl_type. */
89static inline unsigned long *devnode_bits(int vfl_type)
90{
91 return devnode_nums[vfl_type];
92}
93#endif
94
95/* Mark device node number vdev->num as used */
96static inline void devnode_set(struct video_device *vdev)
97{
98 set_bit(vdev->num, devnode_bits(vdev->vfl_type));
99}
100
101/* Mark device node number vdev->num as unused */
102static inline void devnode_clear(struct video_device *vdev)
103{
104 clear_bit(vdev->num, devnode_bits(vdev->vfl_type));
105}
106
107/* Try to find a free device node number in the range [from, to> */
108static inline int devnode_find(struct video_device *vdev, int from, int to)
109{
110 return find_next_zero_bit(devnode_bits(vdev->vfl_type), to, from);
111}
112
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300113struct video_device *video_device_alloc(void)
114{
Hans Verkuilbfa8a272008-08-23 07:48:38 -0300115 return kzalloc(sizeof(struct video_device), GFP_KERNEL);
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300116}
117EXPORT_SYMBOL(video_device_alloc);
118
Hans Verkuildc93a702008-12-19 21:28:27 -0300119void video_device_release(struct video_device *vdev)
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300120{
Hans Verkuildc93a702008-12-19 21:28:27 -0300121 kfree(vdev);
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300122}
123EXPORT_SYMBOL(video_device_release);
124
Hans Verkuildc93a702008-12-19 21:28:27 -0300125void video_device_release_empty(struct video_device *vdev)
Hans Verkuilf9e86b52008-08-23 05:47:41 -0300126{
127 /* Do nothing */
128 /* Only valid when the video_device struct is a static. */
129}
130EXPORT_SYMBOL(video_device_release_empty);
131
Hans Verkuildc93a702008-12-19 21:28:27 -0300132static inline void video_get(struct video_device *vdev)
Hans Verkuil7f8ecfa2008-08-29 17:31:35 -0300133{
Hans Verkuildc93a702008-12-19 21:28:27 -0300134 get_device(&vdev->dev);
135}
136
137static inline void video_put(struct video_device *vdev)
138{
139 put_device(&vdev->dev);
140}
141
142/* Called when the last user of the video device exits. */
143static void v4l2_device_release(struct device *cd)
144{
145 struct video_device *vdev = to_video_device(cd);
Hans Verkuilbedf8bc2011-03-12 06:37:19 -0300146 struct v4l2_device *v4l2_dev = vdev->v4l2_dev;
Hans Verkuil7f8ecfa2008-08-29 17:31:35 -0300147
148 mutex_lock(&videodev_lock);
Hans Verkuildc93a702008-12-19 21:28:27 -0300149 if (video_device[vdev->minor] != vdev) {
Hans Verkuil6ea9a182008-08-30 09:40:47 -0300150 mutex_unlock(&videodev_lock);
Hans Verkuildc93a702008-12-19 21:28:27 -0300151 /* should not happen */
152 WARN_ON(1);
Hans Verkuil6ea9a182008-08-30 09:40:47 -0300153 return;
154 }
Hans Verkuil7f8ecfa2008-08-29 17:31:35 -0300155
156 /* Free up this device for reuse */
Hans Verkuildc93a702008-12-19 21:28:27 -0300157 video_device[vdev->minor] = NULL;
158
159 /* Delete the cdev on this minor as well */
160 cdev_del(vdev->cdev);
161 /* Just in case some driver tries to access this from
162 the release() callback. */
163 vdev->cdev = NULL;
164
Hans Verkuil22e22122009-09-06 07:13:14 -0300165 /* Mark device node number as free */
Hans Verkuil5062cb72009-09-07 03:40:24 -0300166 devnode_clear(vdev);
Hans Verkuildc93a702008-12-19 21:28:27 -0300167
Hans Verkuil7f8ecfa2008-08-29 17:31:35 -0300168 mutex_unlock(&videodev_lock);
169
Laurent Pinchartc064b8e2011-06-15 05:20:34 -0300170#if defined(CONFIG_MEDIA_CONTROLLER)
171 if (vdev->v4l2_dev && vdev->v4l2_dev->mdev &&
172 vdev->vfl_type != VFL_TYPE_SUBDEV)
173 media_device_unregister_entity(&vdev->entity);
174#endif
175
Hans Verkuil8280b662011-09-06 10:23:18 -0300176 /* Do not call v4l2_device_put if there is no release callback set.
177 * Drivers that have no v4l2_device release callback might free the
178 * v4l2_dev instance in the video_device release callback below, so we
179 * must perform this check here.
180 *
181 * TODO: In the long run all drivers that use v4l2_device should use the
182 * v4l2_device release callback. This check will then be unnecessary.
183 */
184 if (v4l2_dev->release == NULL)
185 v4l2_dev = NULL;
186
Hans Verkuil7f8ecfa2008-08-29 17:31:35 -0300187 /* Release video_device and perform other
188 cleanups as needed. */
Hans Verkuildc93a702008-12-19 21:28:27 -0300189 vdev->release(vdev);
Hans Verkuilbedf8bc2011-03-12 06:37:19 -0300190
191 /* Decrease v4l2_device refcount */
192 if (v4l2_dev)
193 v4l2_device_put(v4l2_dev);
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300194}
195
196static struct class video_class = {
197 .name = VIDEO_NAME,
198 .dev_attrs = video_device_attrs,
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300199};
200
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300201struct video_device *video_devdata(struct file *file)
202{
203 return video_device[iminor(file->f_path.dentry->d_inode)];
204}
205EXPORT_SYMBOL(video_devdata);
206
Hans Verkuil02265492010-12-29 10:05:02 -0300207
208/* Priority handling */
209
210static inline bool prio_is_valid(enum v4l2_priority prio)
211{
212 return prio == V4L2_PRIORITY_BACKGROUND ||
213 prio == V4L2_PRIORITY_INTERACTIVE ||
214 prio == V4L2_PRIORITY_RECORD;
215}
216
217void v4l2_prio_init(struct v4l2_prio_state *global)
218{
219 memset(global, 0, sizeof(*global));
220}
221EXPORT_SYMBOL(v4l2_prio_init);
222
223int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
224 enum v4l2_priority new)
225{
226 if (!prio_is_valid(new))
227 return -EINVAL;
228 if (*local == new)
229 return 0;
230
231 atomic_inc(&global->prios[new]);
232 if (prio_is_valid(*local))
233 atomic_dec(&global->prios[*local]);
234 *local = new;
235 return 0;
236}
237EXPORT_SYMBOL(v4l2_prio_change);
238
239void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local)
240{
241 v4l2_prio_change(global, local, V4L2_PRIORITY_DEFAULT);
242}
243EXPORT_SYMBOL(v4l2_prio_open);
244
245void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local)
246{
247 if (prio_is_valid(local))
248 atomic_dec(&global->prios[local]);
249}
250EXPORT_SYMBOL(v4l2_prio_close);
251
252enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global)
253{
254 if (atomic_read(&global->prios[V4L2_PRIORITY_RECORD]) > 0)
255 return V4L2_PRIORITY_RECORD;
256 if (atomic_read(&global->prios[V4L2_PRIORITY_INTERACTIVE]) > 0)
257 return V4L2_PRIORITY_INTERACTIVE;
258 if (atomic_read(&global->prios[V4L2_PRIORITY_BACKGROUND]) > 0)
259 return V4L2_PRIORITY_BACKGROUND;
260 return V4L2_PRIORITY_UNSET;
261}
262EXPORT_SYMBOL(v4l2_prio_max);
263
264int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local)
265{
266 return (local < v4l2_prio_max(global)) ? -EBUSY : 0;
267}
268EXPORT_SYMBOL(v4l2_prio_check);
269
270
Hans Verkuildc93a702008-12-19 21:28:27 -0300271static ssize_t v4l2_read(struct file *filp, char __user *buf,
272 size_t sz, loff_t *off)
273{
274 struct video_device *vdev = video_devdata(filp);
Hans Verkuil28778422010-11-26 06:43:51 -0300275 int ret = -ENODEV;
Hans Verkuildc93a702008-12-19 21:28:27 -0300276
277 if (!vdev->fops->read)
278 return -EINVAL;
Hans Verkuil28778422010-11-26 06:43:51 -0300279 if (vdev->lock && mutex_lock_interruptible(vdev->lock))
280 return -ERESTARTSYS;
Hans Verkuilee6869a2010-09-26 08:47:38 -0300281 if (video_is_registered(vdev))
282 ret = vdev->fops->read(filp, buf, sz, off);
283 if (vdev->lock)
284 mutex_unlock(vdev->lock);
285 return ret;
Hans Verkuildc93a702008-12-19 21:28:27 -0300286}
287
288static ssize_t v4l2_write(struct file *filp, const char __user *buf,
289 size_t sz, loff_t *off)
290{
291 struct video_device *vdev = video_devdata(filp);
Hans Verkuil28778422010-11-26 06:43:51 -0300292 int ret = -ENODEV;
Hans Verkuildc93a702008-12-19 21:28:27 -0300293
294 if (!vdev->fops->write)
295 return -EINVAL;
Hans Verkuil28778422010-11-26 06:43:51 -0300296 if (vdev->lock && mutex_lock_interruptible(vdev->lock))
297 return -ERESTARTSYS;
Hans Verkuilee6869a2010-09-26 08:47:38 -0300298 if (video_is_registered(vdev))
299 ret = vdev->fops->write(filp, buf, sz, off);
300 if (vdev->lock)
301 mutex_unlock(vdev->lock);
302 return ret;
Hans Verkuildc93a702008-12-19 21:28:27 -0300303}
304
305static unsigned int v4l2_poll(struct file *filp, struct poll_table_struct *poll)
306{
307 struct video_device *vdev = video_devdata(filp);
Hans Verkuil28778422010-11-26 06:43:51 -0300308 int ret = POLLERR | POLLHUP;
Hans Verkuildc93a702008-12-19 21:28:27 -0300309
Hans Verkuilee6869a2010-09-26 08:47:38 -0300310 if (!vdev->fops->poll)
Hans Verkuil28778422010-11-26 06:43:51 -0300311 return DEFAULT_POLLMASK;
Hans Verkuilee6869a2010-09-26 08:47:38 -0300312 if (vdev->lock)
313 mutex_lock(vdev->lock);
314 if (video_is_registered(vdev))
315 ret = vdev->fops->poll(filp, poll);
316 if (vdev->lock)
317 mutex_unlock(vdev->lock);
318 return ret;
Hans Verkuildc93a702008-12-19 21:28:27 -0300319}
320
Arnd Bergmann86a5ef72010-07-04 00:15:09 +0200321static long v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
Hans Verkuildc93a702008-12-19 21:28:27 -0300322{
323 struct video_device *vdev = video_devdata(filp);
Mauro Carvalho Chehab72420632010-10-09 16:43:40 -0300324 int ret = -ENODEV;
Hans Verkuildc93a702008-12-19 21:28:27 -0300325
Arnd Bergmann86a5ef72010-07-04 00:15:09 +0200326 if (vdev->fops->unlocked_ioctl) {
Hans Verkuil28778422010-11-26 06:43:51 -0300327 if (vdev->lock && mutex_lock_interruptible(vdev->lock))
328 return -ERESTARTSYS;
Mauro Carvalho Chehab72420632010-10-09 16:43:40 -0300329 if (video_is_registered(vdev))
330 ret = vdev->fops->unlocked_ioctl(filp, cmd, arg);
Hans Verkuilee6869a2010-09-26 08:47:38 -0300331 if (vdev->lock)
332 mutex_unlock(vdev->lock);
Arnd Bergmann86a5ef72010-07-04 00:15:09 +0200333 } else if (vdev->fops->ioctl) {
Hans Verkuil879aa242010-11-26 06:47:28 -0300334 /* This code path is a replacement for the BKL. It is a major
335 * hack but it will have to do for those drivers that are not
336 * yet converted to use unlocked_ioctl.
337 *
338 * There are two options: if the driver implements struct
339 * v4l2_device, then the lock defined there is used to
340 * serialize the ioctls. Otherwise the v4l2 core lock defined
341 * below is used. This lock is really bad since it serializes
342 * completely independent devices.
343 *
344 * Both variants suffer from the same problem: if the driver
345 * sleeps, then it blocks all ioctls since the lock is still
346 * held. This is very common for VIDIOC_DQBUF since that
347 * normally waits for a frame to arrive. As a result any other
348 * ioctl calls will proceed very, very slowly since each call
349 * will have to wait for the VIDIOC_QBUF to finish. Things that
350 * should take 0.01s may now take 10-20 seconds.
351 *
352 * The workaround is to *not* take the lock for VIDIOC_DQBUF.
353 * This actually works OK for videobuf-based drivers, since
354 * videobuf will take its own internal lock.
355 */
Arnd Bergmann0edf2e52010-10-27 09:30:32 -0300356 static DEFINE_MUTEX(v4l2_ioctl_mutex);
Hans Verkuil879aa242010-11-26 06:47:28 -0300357 struct mutex *m = vdev->v4l2_dev ?
358 &vdev->v4l2_dev->ioctl_lock : &v4l2_ioctl_mutex;
Arnd Bergmann0edf2e52010-10-27 09:30:32 -0300359
Hans Verkuil879aa242010-11-26 06:47:28 -0300360 if (cmd != VIDIOC_DQBUF && mutex_lock_interruptible(m))
361 return -ERESTARTSYS;
Mauro Carvalho Chehab72420632010-10-09 16:43:40 -0300362 if (video_is_registered(vdev))
363 ret = vdev->fops->ioctl(filp, cmd, arg);
Hans Verkuil879aa242010-11-26 06:47:28 -0300364 if (cmd != VIDIOC_DQBUF)
365 mutex_unlock(m);
Arnd Bergmann86a5ef72010-07-04 00:15:09 +0200366 } else
367 ret = -ENOTTY;
Hans Verkuildc93a702008-12-19 21:28:27 -0300368
Arnd Bergmann86a5ef72010-07-04 00:15:09 +0200369 return ret;
Hans Verkuildc93a702008-12-19 21:28:27 -0300370}
371
Bob Liuecc65172011-05-06 05:20:09 -0300372#ifdef CONFIG_MMU
373#define v4l2_get_unmapped_area NULL
374#else
375static unsigned long v4l2_get_unmapped_area(struct file *filp,
376 unsigned long addr, unsigned long len, unsigned long pgoff,
377 unsigned long flags)
378{
379 struct video_device *vdev = video_devdata(filp);
380
381 if (!vdev->fops->get_unmapped_area)
382 return -ENOSYS;
383 if (!video_is_registered(vdev))
384 return -ENODEV;
385 return vdev->fops->get_unmapped_area(filp, addr, len, pgoff, flags);
386}
387#endif
388
Hans Verkuildc93a702008-12-19 21:28:27 -0300389static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm)
390{
391 struct video_device *vdev = video_devdata(filp);
Hans Verkuilee6869a2010-09-26 08:47:38 -0300392 int ret = -ENODEV;
Hans Verkuildc93a702008-12-19 21:28:27 -0300393
Hans Verkuilee6869a2010-09-26 08:47:38 -0300394 if (!vdev->fops->mmap)
395 return ret;
Hans Verkuil28778422010-11-26 06:43:51 -0300396 if (vdev->lock && mutex_lock_interruptible(vdev->lock))
397 return -ERESTARTSYS;
Hans Verkuilee6869a2010-09-26 08:47:38 -0300398 if (video_is_registered(vdev))
399 ret = vdev->fops->mmap(filp, vm);
400 if (vdev->lock)
401 mutex_unlock(vdev->lock);
402 return ret;
Hans Verkuildc93a702008-12-19 21:28:27 -0300403}
404
405/* Override for the open function */
406static int v4l2_open(struct inode *inode, struct file *filp)
407{
408 struct video_device *vdev;
Hans Verkuil65d9ff92009-03-29 20:19:38 -0300409 int ret = 0;
Hans Verkuildc93a702008-12-19 21:28:27 -0300410
411 /* Check if the video device is available */
412 mutex_lock(&videodev_lock);
413 vdev = video_devdata(filp);
Hans Verkuilee6869a2010-09-26 08:47:38 -0300414 /* return ENODEV if the video device has already been removed. */
Hans Verkuilca9afe62010-11-26 06:54:53 -0300415 if (vdev == NULL || !video_is_registered(vdev)) {
Hans Verkuildc93a702008-12-19 21:28:27 -0300416 mutex_unlock(&videodev_lock);
417 return -ENODEV;
418 }
419 /* and increase the device refcount */
420 video_get(vdev);
421 mutex_unlock(&videodev_lock);
Hans Verkuilee6869a2010-09-26 08:47:38 -0300422 if (vdev->fops->open) {
Hans Verkuil28778422010-11-26 06:43:51 -0300423 if (vdev->lock && mutex_lock_interruptible(vdev->lock)) {
424 ret = -ERESTARTSYS;
425 goto err;
426 }
Hans Verkuilee6869a2010-09-26 08:47:38 -0300427 if (video_is_registered(vdev))
428 ret = vdev->fops->open(filp);
429 else
430 ret = -ENODEV;
431 if (vdev->lock)
432 mutex_unlock(vdev->lock);
433 }
Hans Verkuil65d9ff92009-03-29 20:19:38 -0300434
Hans Verkuil28778422010-11-26 06:43:51 -0300435err:
Hans Verkuildc93a702008-12-19 21:28:27 -0300436 /* decrease the refcount in case of an error */
Laurent Pinchartc064b8e2011-06-15 05:20:34 -0300437 if (ret)
Hans Verkuildc93a702008-12-19 21:28:27 -0300438 video_put(vdev);
439 return ret;
440}
441
442/* Override for the release function */
443static int v4l2_release(struct inode *inode, struct file *filp)
444{
445 struct video_device *vdev = video_devdata(filp);
Hans Verkuil65d9ff92009-03-29 20:19:38 -0300446 int ret = 0;
447
Hans Verkuilee6869a2010-09-26 08:47:38 -0300448 if (vdev->fops->release) {
449 if (vdev->lock)
450 mutex_lock(vdev->lock);
Hans Verkuil65d9ff92009-03-29 20:19:38 -0300451 vdev->fops->release(filp);
Hans Verkuilee6869a2010-09-26 08:47:38 -0300452 if (vdev->lock)
453 mutex_unlock(vdev->lock);
454 }
Hans Verkuildc93a702008-12-19 21:28:27 -0300455 /* decrease the refcount unconditionally since the release()
456 return value is ignored. */
457 video_put(vdev);
458 return ret;
459}
460
Hans Verkuildc93a702008-12-19 21:28:27 -0300461static const struct file_operations v4l2_fops = {
462 .owner = THIS_MODULE,
463 .read = v4l2_read,
464 .write = v4l2_write,
465 .open = v4l2_open,
Bob Liuecc65172011-05-06 05:20:09 -0300466 .get_unmapped_area = v4l2_get_unmapped_area,
Hans Verkuildc93a702008-12-19 21:28:27 -0300467 .mmap = v4l2_mmap,
Arnd Bergmann86a5ef72010-07-04 00:15:09 +0200468 .unlocked_ioctl = v4l2_ioctl,
Hans Verkuildc93a702008-12-19 21:28:27 -0300469#ifdef CONFIG_COMPAT
Hans Verkuil9bb7cde2008-12-30 06:42:40 -0300470 .compat_ioctl = v4l2_compat_ioctl32,
Hans Verkuildc93a702008-12-19 21:28:27 -0300471#endif
472 .release = v4l2_release,
473 .poll = v4l2_poll,
474 .llseek = no_llseek,
475};
476
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300477/**
Hans Verkuil7ae0cd92009-06-19 11:32:56 -0300478 * get_index - assign stream index number based on parent device
Hans Verkuildc93a702008-12-19 21:28:27 -0300479 * @vdev: video_device to assign index number to, vdev->parent should be assigned
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300480 *
Hans Verkuildc93a702008-12-19 21:28:27 -0300481 * Note that when this is called the new device has not yet been registered
Hans Verkuil7ae0cd92009-06-19 11:32:56 -0300482 * in the video_device array, but it was able to obtain a minor number.
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300483 *
Hans Verkuil7ae0cd92009-06-19 11:32:56 -0300484 * This means that we can always obtain a free stream index number since
485 * the worst case scenario is that there are VIDEO_NUM_DEVICES - 1 slots in
486 * use of the video_device array.
487 *
488 * Returns a free index number.
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300489 */
Hans Verkuil7ae0cd92009-06-19 11:32:56 -0300490static int get_index(struct video_device *vdev)
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300491{
Hans Verkuil775a05d2009-02-14 11:31:01 -0300492 /* This can be static since this function is called with the global
493 videodev_lock held. */
494 static DECLARE_BITMAP(used, VIDEO_NUM_DEVICES);
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300495 int i;
496
Hans Verkuil7ae0cd92009-06-19 11:32:56 -0300497 /* Some drivers do not set the parent. In that case always return 0. */
Hans Verkuil806e5b72008-12-19 09:10:56 -0300498 if (vdev->parent == NULL)
Hans Verkuil7ae0cd92009-06-19 11:32:56 -0300499 return 0;
Hans Verkuil775a05d2009-02-14 11:31:01 -0300500
501 bitmap_zero(used, VIDEO_NUM_DEVICES);
Hans Verkuil806e5b72008-12-19 09:10:56 -0300502
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300503 for (i = 0; i < VIDEO_NUM_DEVICES; i++) {
504 if (video_device[i] != NULL &&
Hans Verkuil5e85e732008-07-20 06:31:39 -0300505 video_device[i]->parent == vdev->parent) {
Hans Verkuil775a05d2009-02-14 11:31:01 -0300506 set_bit(video_device[i]->index, used);
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300507 }
508 }
509
Hans Verkuil7ae0cd92009-06-19 11:32:56 -0300510 return find_first_zero_bit(used, VIDEO_NUM_DEVICES);
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300511}
512
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300513/**
Laurent Pinchart2096a5d2009-12-09 08:38:49 -0300514 * __video_register_device - register video4linux devices
Hans Verkuildc93a702008-12-19 21:28:27 -0300515 * @vdev: video device structure we want to register
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300516 * @type: type of device to register
Hans Verkuil22e22122009-09-06 07:13:14 -0300517 * @nr: which device node number (0 == /dev/video0, 1 == /dev/video1, ...
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300518 * -1 == first free)
Hans Verkuil6b5270d2009-09-06 07:54:00 -0300519 * @warn_if_nr_in_use: warn if the desired device node number
520 * was already in use and another number was chosen instead.
Laurent Pinchart2096a5d2009-12-09 08:38:49 -0300521 * @owner: module that owns the video device node
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300522 *
Hans Verkuil22e22122009-09-06 07:13:14 -0300523 * The registration code assigns minor numbers and device node numbers
524 * based on the requested type and registers the new device node with
525 * the kernel.
Hans Verkuil46b63372010-12-31 11:47:23 -0300526 *
527 * This function assumes that struct video_device was zeroed when it
528 * was allocated and does not contain any stale date.
529 *
Hans Verkuil22e22122009-09-06 07:13:14 -0300530 * An error is returned if no free minor or device node number could be
531 * found, or if the registration of the device node failed.
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300532 *
533 * Zero is returned on success.
534 *
535 * Valid types are
536 *
537 * %VFL_TYPE_GRABBER - A frame grabber
538 *
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300539 * %VFL_TYPE_VBI - Vertical blank data (undecoded)
540 *
541 * %VFL_TYPE_RADIO - A radio card
Laurent Pinchart2096a5d2009-12-09 08:38:49 -0300542 *
543 * %VFL_TYPE_SUBDEV - A subdevice
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300544 */
Laurent Pinchart2096a5d2009-12-09 08:38:49 -0300545int __video_register_device(struct video_device *vdev, int type, int nr,
546 int warn_if_nr_in_use, struct module *owner)
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300547{
548 int i = 0;
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300549 int ret;
Hans Verkuildd896012008-10-04 08:36:54 -0300550 int minor_offset = 0;
551 int minor_cnt = VIDEO_NUM_DEVICES;
552 const char *name_base;
Hans Verkuildc93a702008-12-19 21:28:27 -0300553
554 /* A minor value of -1 marks this video device as never
555 having been registered */
Trent Piepho428c8d12009-03-03 18:51:52 -0300556 vdev->minor = -1;
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300557
Hans Verkuild6e74972008-08-23 06:27:59 -0300558 /* the release callback MUST be present */
Trent Piepho428c8d12009-03-03 18:51:52 -0300559 WARN_ON(!vdev->release);
560 if (!vdev->release)
Henrik Kretzschmaree7aa9f2008-08-22 16:41:03 -0300561 return -EINVAL;
562
Sakari Ailus1babcb42010-03-23 09:25:26 -0300563 /* v4l2_fh support */
564 spin_lock_init(&vdev->fh_lock);
565 INIT_LIST_HEAD(&vdev->fh_list);
566
Hans Verkuildc93a702008-12-19 21:28:27 -0300567 /* Part 1: check device type */
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300568 switch (type) {
569 case VFL_TYPE_GRABBER:
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300570 name_base = "video";
571 break;
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300572 case VFL_TYPE_VBI:
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300573 name_base = "vbi";
574 break;
575 case VFL_TYPE_RADIO:
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300576 name_base = "radio";
577 break;
Laurent Pinchart2096a5d2009-12-09 08:38:49 -0300578 case VFL_TYPE_SUBDEV:
579 name_base = "v4l-subdev";
580 break;
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300581 default:
582 printk(KERN_ERR "%s called with unknown type: %d\n",
583 __func__, type);
Henrik Kretzschmar46f2c212008-09-03 16:47:39 -0300584 return -EINVAL;
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300585 }
586
Hans Verkuildc93a702008-12-19 21:28:27 -0300587 vdev->vfl_type = type;
588 vdev->cdev = NULL;
Hans Verkuil11bbc1c2010-05-16 09:24:06 -0300589 if (vdev->v4l2_dev) {
590 if (vdev->v4l2_dev->dev)
591 vdev->parent = vdev->v4l2_dev->dev;
592 if (vdev->ctrl_handler == NULL)
593 vdev->ctrl_handler = vdev->v4l2_dev->ctrl_handler;
Hans Verkuilb1a873a2011-03-22 10:14:07 -0300594 /* If the prio state pointer is NULL, then use the v4l2_device
595 prio state. */
596 if (vdev->prio == NULL)
Hans Verkuil0f62fd62011-02-24 10:42:24 -0300597 vdev->prio = &vdev->v4l2_dev->prio;
Hans Verkuil11bbc1c2010-05-16 09:24:06 -0300598 }
Hans Verkuildd896012008-10-04 08:36:54 -0300599
Hans Verkuil22e22122009-09-06 07:13:14 -0300600 /* Part 2: find a free minor, device node number and device index. */
Hans Verkuildd896012008-10-04 08:36:54 -0300601#ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
602 /* Keep the ranges for the first four types for historical
603 * reasons.
604 * Newer devices (not yet in place) should use the range
605 * of 128-191 and just pick the first free minor there
606 * (new style). */
607 switch (type) {
608 case VFL_TYPE_GRABBER:
609 minor_offset = 0;
610 minor_cnt = 64;
611 break;
612 case VFL_TYPE_RADIO:
613 minor_offset = 64;
614 minor_cnt = 64;
615 break;
Hans Verkuildd896012008-10-04 08:36:54 -0300616 case VFL_TYPE_VBI:
617 minor_offset = 224;
618 minor_cnt = 32;
619 break;
620 default:
621 minor_offset = 128;
622 minor_cnt = 64;
623 break;
624 }
625#endif
626
Hans Verkuil22e22122009-09-06 07:13:14 -0300627 /* Pick a device node number */
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300628 mutex_lock(&videodev_lock);
Hans Verkuil5062cb72009-09-07 03:40:24 -0300629 nr = devnode_find(vdev, nr == -1 ? 0 : nr, minor_cnt);
Hans Verkuildd896012008-10-04 08:36:54 -0300630 if (nr == minor_cnt)
Hans Verkuil5062cb72009-09-07 03:40:24 -0300631 nr = devnode_find(vdev, 0, minor_cnt);
Hans Verkuildd896012008-10-04 08:36:54 -0300632 if (nr == minor_cnt) {
Hans Verkuil22e22122009-09-06 07:13:14 -0300633 printk(KERN_ERR "could not get a free device node number\n");
Hans Verkuildd896012008-10-04 08:36:54 -0300634 mutex_unlock(&videodev_lock);
635 return -ENFILE;
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300636 }
Hans Verkuildd896012008-10-04 08:36:54 -0300637#ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
Hans Verkuil22e22122009-09-06 07:13:14 -0300638 /* 1-on-1 mapping of device node number to minor number */
Hans Verkuildd896012008-10-04 08:36:54 -0300639 i = nr;
640#else
Hans Verkuil22e22122009-09-06 07:13:14 -0300641 /* The device node number and minor numbers are independent, so
642 we just find the first free minor number. */
Hans Verkuildd896012008-10-04 08:36:54 -0300643 for (i = 0; i < VIDEO_NUM_DEVICES; i++)
644 if (video_device[i] == NULL)
645 break;
646 if (i == VIDEO_NUM_DEVICES) {
647 mutex_unlock(&videodev_lock);
648 printk(KERN_ERR "could not get a free minor\n");
649 return -ENFILE;
650 }
651#endif
Hans Verkuildc93a702008-12-19 21:28:27 -0300652 vdev->minor = i + minor_offset;
653 vdev->num = nr;
Hans Verkuil5062cb72009-09-07 03:40:24 -0300654 devnode_set(vdev);
655
Hans Verkuildc93a702008-12-19 21:28:27 -0300656 /* Should not happen since we thought this minor was free */
657 WARN_ON(video_device[vdev->minor] != NULL);
Hans Verkuil7ae0cd92009-06-19 11:32:56 -0300658 vdev->index = get_index(vdev);
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300659 mutex_unlock(&videodev_lock);
660
Hans Verkuildc93a702008-12-19 21:28:27 -0300661 /* Part 3: Initialize the character device */
662 vdev->cdev = cdev_alloc();
663 if (vdev->cdev == NULL) {
664 ret = -ENOMEM;
665 goto cleanup;
666 }
Arnd Bergmann86a5ef72010-07-04 00:15:09 +0200667 vdev->cdev->ops = &v4l2_fops;
Laurent Pinchart2096a5d2009-12-09 08:38:49 -0300668 vdev->cdev->owner = owner;
Hans Verkuildc93a702008-12-19 21:28:27 -0300669 ret = cdev_add(vdev->cdev, MKDEV(VIDEO_MAJOR, vdev->minor), 1);
Hans Verkuil7f8ecfa2008-08-29 17:31:35 -0300670 if (ret < 0) {
671 printk(KERN_ERR "%s: cdev_add failed\n", __func__);
Hans Verkuildc93a702008-12-19 21:28:27 -0300672 kfree(vdev->cdev);
673 vdev->cdev = NULL;
674 goto cleanup;
Hans Verkuil7f8ecfa2008-08-29 17:31:35 -0300675 }
Hans Verkuildc93a702008-12-19 21:28:27 -0300676
677 /* Part 4: register the device with sysfs */
Hans Verkuildc93a702008-12-19 21:28:27 -0300678 vdev->dev.class = &video_class;
679 vdev->dev.devt = MKDEV(VIDEO_MAJOR, vdev->minor);
680 if (vdev->parent)
681 vdev->dev.parent = vdev->parent;
Hans Verkuil22e22122009-09-06 07:13:14 -0300682 dev_set_name(&vdev->dev, "%s%d", name_base, vdev->num);
Hans Verkuildc93a702008-12-19 21:28:27 -0300683 ret = device_register(&vdev->dev);
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300684 if (ret < 0) {
685 printk(KERN_ERR "%s: device_register failed\n", __func__);
Hans Verkuildc93a702008-12-19 21:28:27 -0300686 goto cleanup;
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300687 }
Hans Verkuildc93a702008-12-19 21:28:27 -0300688 /* Register the release callback that will be called when the last
689 reference to the device goes away. */
690 vdev->dev.release = v4l2_device_release;
691
Hans Verkuil6b5270d2009-09-06 07:54:00 -0300692 if (nr != -1 && nr != vdev->num && warn_if_nr_in_use)
Laurent Pincharteac8ea52009-11-27 13:56:50 -0300693 printk(KERN_WARNING "%s: requested %s%d, got %s\n", __func__,
694 name_base, nr, video_device_node_name(vdev));
Hans Verkuilbedf8bc2011-03-12 06:37:19 -0300695
696 /* Increase v4l2_device refcount */
697 if (vdev->v4l2_dev)
698 v4l2_device_get(vdev->v4l2_dev);
699
Laurent Pinchart2c0ab672009-12-09 08:40:10 -0300700#if defined(CONFIG_MEDIA_CONTROLLER)
701 /* Part 5: Register the entity. */
Laurent Pinchartc4f0b782011-04-08 09:04:06 -0300702 if (vdev->v4l2_dev && vdev->v4l2_dev->mdev &&
703 vdev->vfl_type != VFL_TYPE_SUBDEV) {
Laurent Pinchart2c0ab672009-12-09 08:40:10 -0300704 vdev->entity.type = MEDIA_ENT_T_DEVNODE_V4L;
705 vdev->entity.name = vdev->name;
706 vdev->entity.v4l.major = VIDEO_MAJOR;
707 vdev->entity.v4l.minor = vdev->minor;
708 ret = media_device_register_entity(vdev->v4l2_dev->mdev,
709 &vdev->entity);
710 if (ret < 0)
711 printk(KERN_WARNING
712 "%s: media_device_register_entity failed\n",
713 __func__);
714 }
715#endif
716 /* Part 6: Activate this minor. The char device can now be used. */
Laurent Pinchart957b4aa2009-11-27 13:57:22 -0300717 set_bit(V4L2_FL_REGISTERED, &vdev->flags);
Hans Verkuildc93a702008-12-19 21:28:27 -0300718 mutex_lock(&videodev_lock);
719 video_device[vdev->minor] = vdev;
720 mutex_unlock(&videodev_lock);
Laurent Pinchart2c0ab672009-12-09 08:40:10 -0300721
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300722 return 0;
723
Hans Verkuildc93a702008-12-19 21:28:27 -0300724cleanup:
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300725 mutex_lock(&videodev_lock);
Hans Verkuildc93a702008-12-19 21:28:27 -0300726 if (vdev->cdev)
727 cdev_del(vdev->cdev);
Hans Verkuil5062cb72009-09-07 03:40:24 -0300728 devnode_clear(vdev);
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300729 mutex_unlock(&videodev_lock);
Hans Verkuildc93a702008-12-19 21:28:27 -0300730 /* Mark this video device as never having been registered. */
731 vdev->minor = -1;
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300732 return ret;
733}
Laurent Pinchart2096a5d2009-12-09 08:38:49 -0300734EXPORT_SYMBOL(__video_register_device);
Hans Verkuil6b5270d2009-09-06 07:54:00 -0300735
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300736/**
737 * video_unregister_device - unregister a video4linux device
Hans Verkuildc93a702008-12-19 21:28:27 -0300738 * @vdev: the device to unregister
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300739 *
Hans Verkuildc93a702008-12-19 21:28:27 -0300740 * This unregisters the passed device. Future open calls will
741 * be met with errors.
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300742 */
Hans Verkuildc93a702008-12-19 21:28:27 -0300743void video_unregister_device(struct video_device *vdev)
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300744{
Hans Verkuildc93a702008-12-19 21:28:27 -0300745 /* Check if vdev was ever registered at all */
Laurent Pinchart957b4aa2009-11-27 13:57:22 -0300746 if (!vdev || !video_is_registered(vdev))
Hans Verkuildc93a702008-12-19 21:28:27 -0300747 return;
748
Hans Verkuilca9afe62010-11-26 06:54:53 -0300749 mutex_lock(&videodev_lock);
750 /* This must be in a critical section to prevent a race with v4l2_open.
751 * Once this bit has been cleared video_get may never be called again.
752 */
Laurent Pinchart957b4aa2009-11-27 13:57:22 -0300753 clear_bit(V4L2_FL_REGISTERED, &vdev->flags);
Hans Verkuilca9afe62010-11-26 06:54:53 -0300754 mutex_unlock(&videodev_lock);
Hans Verkuildc93a702008-12-19 21:28:27 -0300755 device_unregister(&vdev->dev);
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300756}
757EXPORT_SYMBOL(video_unregister_device);
758
759/*
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300760 * Initialise video for linux
761 */
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300762static int __init videodev_init(void)
763{
Hans Verkuil7f8ecfa2008-08-29 17:31:35 -0300764 dev_t dev = MKDEV(VIDEO_MAJOR, 0);
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300765 int ret;
766
767 printk(KERN_INFO "Linux video capture interface: v2.00\n");
Hans Verkuil7f8ecfa2008-08-29 17:31:35 -0300768 ret = register_chrdev_region(dev, VIDEO_NUM_DEVICES, VIDEO_NAME);
769 if (ret < 0) {
770 printk(KERN_WARNING "videodev: unable to get major %d\n",
771 VIDEO_MAJOR);
772 return ret;
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300773 }
774
775 ret = class_register(&video_class);
776 if (ret < 0) {
Hans Verkuil7f8ecfa2008-08-29 17:31:35 -0300777 unregister_chrdev_region(dev, VIDEO_NUM_DEVICES);
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300778 printk(KERN_WARNING "video_dev: class_register failed\n");
779 return -EIO;
780 }
781
782 return 0;
783}
784
785static void __exit videodev_exit(void)
786{
Hans Verkuil7f8ecfa2008-08-29 17:31:35 -0300787 dev_t dev = MKDEV(VIDEO_MAJOR, 0);
788
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300789 class_unregister(&video_class);
Hans Verkuil7f8ecfa2008-08-29 17:31:35 -0300790 unregister_chrdev_region(dev, VIDEO_NUM_DEVICES);
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300791}
792
793module_init(videodev_init)
794module_exit(videodev_exit)
795
796MODULE_AUTHOR("Alan Cox, Mauro Carvalho Chehab <mchehab@infradead.org>");
797MODULE_DESCRIPTION("Device registrar for Video4Linux drivers v2");
798MODULE_LICENSE("GPL");
Scott James Remnantcbb72b02009-03-02 15:40:57 -0300799MODULE_ALIAS_CHARDEV_MAJOR(VIDEO_MAJOR);
Hans Verkuil27a5e6d2008-07-20 08:43:17 -0300800
801
802/*
803 * Local variables:
804 * c-basic-offset: 8
805 * End:
806 */