blob: 5f87dd5f1d0b7fe28af648e26d10f142aa2cfab9 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Video capture interface for Linux
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 * Author: Alan Cox, <alan@redhat.com>
13 *
14 * Fixes: 20000516 Claudio Matsuoka <claudio@conectiva.com>
15 * - Added procfs support
16 */
17
18#include <linux/module.h>
19#include <linux/types.h>
20#include <linux/kernel.h>
21#include <linux/sched.h>
22#include <linux/smp_lock.h>
23#include <linux/mm.h>
24#include <linux/string.h>
25#include <linux/errno.h>
26#include <linux/init.h>
27#include <linux/kmod.h>
28#include <linux/slab.h>
29#include <linux/devfs_fs_kernel.h>
30#include <asm/uaccess.h>
31#include <asm/system.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
33#include <linux/videodev.h>
34
35#define VIDEO_NUM_DEVICES 256
36#define VIDEO_NAME "video4linux"
37
38/*
39 * sysfs stuff
40 */
41
42static ssize_t show_name(struct class_device *cd, char *buf)
43{
44 struct video_device *vfd = container_of(cd, struct video_device, class_dev);
45 return sprintf(buf,"%.*s\n",(int)sizeof(vfd->name),vfd->name);
46}
47
48static CLASS_DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
49
50struct video_device *video_device_alloc(void)
51{
52 struct video_device *vfd;
53
Panagiotis Issaris74081872006-01-11 19:40:56 -020054 vfd = kzalloc(sizeof(*vfd),GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070055 return vfd;
56}
57
58void video_device_release(struct video_device *vfd)
59{
60 kfree(vfd);
61}
62
63static void video_release(struct class_device *cd)
64{
65 struct video_device *vfd = container_of(cd, struct video_device, class_dev);
66
Mauro Carvalho Chehabd21838d2006-01-09 15:25:21 -020067#if 1
Michael Krufky50c25ff2006-01-09 15:25:34 -020068 /* needed until all drivers are fixed */
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 if (!vfd->release)
70 return;
71#endif
72 vfd->release(vfd);
73}
74
75static struct class video_class = {
Sigmund Augdal Helberg938606b2005-12-01 00:51:19 -080076 .name = VIDEO_NAME,
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 .release = video_release,
78};
79
80/*
Sigmund Augdal Helberg938606b2005-12-01 00:51:19 -080081 * Active devices
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 */
Sigmund Augdal Helberg938606b2005-12-01 00:51:19 -080083
Linus Torvalds1da177e2005-04-16 15:20:36 -070084static struct video_device *video_device[VIDEO_NUM_DEVICES];
Ingo Molnar1e4baed2006-01-15 07:52:23 -020085static DEFINE_MUTEX(videodev_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070086
87struct video_device* video_devdata(struct file *file)
88{
89 return video_device[iminor(file->f_dentry->d_inode)];
90}
91
92/*
93 * Open a video device.
94 */
95static int video_open(struct inode *inode, struct file *file)
96{
97 unsigned int minor = iminor(inode);
98 int err = 0;
99 struct video_device *vfl;
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800100 const struct file_operations *old_fops;
Sigmund Augdal Helberg938606b2005-12-01 00:51:19 -0800101
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 if(minor>=VIDEO_NUM_DEVICES)
103 return -ENODEV;
Ingo Molnar1e4baed2006-01-15 07:52:23 -0200104 mutex_lock(&videodev_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 vfl=video_device[minor];
106 if(vfl==NULL) {
Ingo Molnar1e4baed2006-01-15 07:52:23 -0200107 mutex_unlock(&videodev_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 request_module("char-major-%d-%d", VIDEO_MAJOR, minor);
Ingo Molnar1e4baed2006-01-15 07:52:23 -0200109 mutex_lock(&videodev_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 vfl=video_device[minor];
111 if (vfl==NULL) {
Ingo Molnar1e4baed2006-01-15 07:52:23 -0200112 mutex_unlock(&videodev_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113 return -ENODEV;
114 }
115 }
116 old_fops = file->f_op;
117 file->f_op = fops_get(vfl->fops);
118 if(file->f_op->open)
119 err = file->f_op->open(inode,file);
120 if (err) {
121 fops_put(file->f_op);
122 file->f_op = fops_get(old_fops);
123 }
124 fops_put(old_fops);
Ingo Molnar1e4baed2006-01-15 07:52:23 -0200125 mutex_unlock(&videodev_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 return err;
127}
128
129/*
130 * helper function -- handles userspace copying for ioctl arguments
131 */
132
133static unsigned int
134video_fix_command(unsigned int cmd)
135{
136 switch (cmd) {
137 case VIDIOC_OVERLAY_OLD:
138 cmd = VIDIOC_OVERLAY;
139 break;
140 case VIDIOC_S_PARM_OLD:
141 cmd = VIDIOC_S_PARM;
142 break;
143 case VIDIOC_S_CTRL_OLD:
144 cmd = VIDIOC_S_CTRL;
145 break;
146 case VIDIOC_G_AUDIO_OLD:
147 cmd = VIDIOC_G_AUDIO;
148 break;
149 case VIDIOC_G_AUDOUT_OLD:
150 cmd = VIDIOC_G_AUDOUT;
151 break;
152 case VIDIOC_CROPCAP_OLD:
153 cmd = VIDIOC_CROPCAP;
154 break;
155 }
156 return cmd;
157}
158
159int
160video_usercopy(struct inode *inode, struct file *file,
161 unsigned int cmd, unsigned long arg,
162 int (*func)(struct inode *inode, struct file *file,
163 unsigned int cmd, void *arg))
164{
165 char sbuf[128];
166 void *mbuf = NULL;
167 void *parg = NULL;
168 int err = -EINVAL;
169
170 cmd = video_fix_command(cmd);
171
172 /* Copy arguments into temp kernel buffer */
173 switch (_IOC_DIR(cmd)) {
174 case _IOC_NONE:
175 parg = NULL;
176 break;
177 case _IOC_READ:
178 case _IOC_WRITE:
179 case (_IOC_WRITE | _IOC_READ):
180 if (_IOC_SIZE(cmd) <= sizeof(sbuf)) {
181 parg = sbuf;
182 } else {
183 /* too big to allocate from stack */
184 mbuf = kmalloc(_IOC_SIZE(cmd),GFP_KERNEL);
185 if (NULL == mbuf)
186 return -ENOMEM;
187 parg = mbuf;
188 }
Sigmund Augdal Helberg938606b2005-12-01 00:51:19 -0800189
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 err = -EFAULT;
191 if (_IOC_DIR(cmd) & _IOC_WRITE)
192 if (copy_from_user(parg, (void __user *)arg, _IOC_SIZE(cmd)))
193 goto out;
194 break;
195 }
196
197 /* call driver */
198 err = func(inode, file, cmd, parg);
199 if (err == -ENOIOCTLCMD)
200 err = -EINVAL;
201 if (err < 0)
202 goto out;
203
204 /* Copy results into user buffer */
205 switch (_IOC_DIR(cmd))
206 {
207 case _IOC_READ:
208 case (_IOC_WRITE | _IOC_READ):
209 if (copy_to_user((void __user *)arg, parg, _IOC_SIZE(cmd)))
210 err = -EFAULT;
211 break;
212 }
213
214out:
Jesper Juhl2ea75332005-11-07 01:01:31 -0800215 kfree(mbuf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 return err;
217}
218
219/*
220 * open/release helper functions -- handle exclusive opens
221 */
222int video_exclusive_open(struct inode *inode, struct file *file)
223{
224 struct video_device *vfl = video_devdata(file);
225 int retval = 0;
226
Ingo Molnar3593cab2006-02-07 06:49:14 -0200227 mutex_lock(&vfl->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 if (vfl->users) {
229 retval = -EBUSY;
230 } else {
231 vfl->users++;
232 }
Ingo Molnar3593cab2006-02-07 06:49:14 -0200233 mutex_unlock(&vfl->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 return retval;
235}
236
237int video_exclusive_release(struct inode *inode, struct file *file)
238{
239 struct video_device *vfl = video_devdata(file);
Sigmund Augdal Helberg938606b2005-12-01 00:51:19 -0800240
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 vfl->users--;
242 return 0;
243}
244
245static struct file_operations video_fops;
246
247/**
248 * video_register_device - register video4linux devices
249 * @vfd: video device structure we want to register
250 * @type: type of device to register
251 * @nr: which device number (0 == /dev/video0, 1 == /dev/video1, ...
252 * -1 == first free)
Sigmund Augdal Helberg938606b2005-12-01 00:51:19 -0800253 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 * The registration code assigns minor numbers based on the type
255 * requested. -ENFILE is returned in all the device slots for this
256 * category are full. If not then the minor field is set and the
257 * driver initialize function is called (if non %NULL).
258 *
259 * Zero is returned on success.
260 *
261 * Valid types are
262 *
263 * %VFL_TYPE_GRABBER - A frame grabber
264 *
265 * %VFL_TYPE_VTX - A teletext device
266 *
267 * %VFL_TYPE_VBI - Vertical blank data (undecoded)
268 *
Sigmund Augdal Helberg938606b2005-12-01 00:51:19 -0800269 * %VFL_TYPE_RADIO - A radio card
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 */
271
272int video_register_device(struct video_device *vfd, int type, int nr)
273{
274 int i=0;
275 int base;
276 int end;
277 char *name_base;
Sigmund Augdal Helberg938606b2005-12-01 00:51:19 -0800278
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 switch(type)
280 {
281 case VFL_TYPE_GRABBER:
Mauro Carvalho Chehab4d0dddb2006-01-23 17:11:07 -0200282 base=MINOR_VFL_TYPE_GRABBER_MIN;
283 end=MINOR_VFL_TYPE_GRABBER_MAX+1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284 name_base = "video";
285 break;
286 case VFL_TYPE_VTX:
Mauro Carvalho Chehab4d0dddb2006-01-23 17:11:07 -0200287 base=MINOR_VFL_TYPE_VTX_MIN;
288 end=MINOR_VFL_TYPE_VTX_MAX+1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 name_base = "vtx";
290 break;
291 case VFL_TYPE_VBI:
Mauro Carvalho Chehab4d0dddb2006-01-23 17:11:07 -0200292 base=MINOR_VFL_TYPE_VBI_MIN;
293 end=MINOR_VFL_TYPE_VBI_MAX+1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 name_base = "vbi";
295 break;
296 case VFL_TYPE_RADIO:
Mauro Carvalho Chehab4d0dddb2006-01-23 17:11:07 -0200297 base=MINOR_VFL_TYPE_RADIO_MIN;
298 end=MINOR_VFL_TYPE_RADIO_MAX+1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 name_base = "radio";
300 break;
301 default:
302 return -1;
303 }
304
305 /* pick a minor number */
Ingo Molnar1e4baed2006-01-15 07:52:23 -0200306 mutex_lock(&videodev_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307 if (nr >= 0 && nr < end-base) {
308 /* use the one the driver asked for */
309 i = base+nr;
310 if (NULL != video_device[i]) {
Ingo Molnar1e4baed2006-01-15 07:52:23 -0200311 mutex_unlock(&videodev_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312 return -ENFILE;
313 }
314 } else {
315 /* use first free */
316 for(i=base;i<end;i++)
317 if (NULL == video_device[i])
318 break;
319 if (i == end) {
Ingo Molnar1e4baed2006-01-15 07:52:23 -0200320 mutex_unlock(&videodev_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 return -ENFILE;
322 }
323 }
324 video_device[i]=vfd;
325 vfd->minor=i;
Ingo Molnar1e4baed2006-01-15 07:52:23 -0200326 mutex_unlock(&videodev_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327
328 sprintf(vfd->devfs_name, "v4l/%s%d", name_base, i - base);
329 devfs_mk_cdev(MKDEV(VIDEO_MAJOR, vfd->minor),
330 S_IFCHR | S_IRUSR | S_IWUSR, vfd->devfs_name);
Ingo Molnar3593cab2006-02-07 06:49:14 -0200331 mutex_init(&vfd->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332
333 /* sysfs class */
Sigmund Augdal Helberg938606b2005-12-01 00:51:19 -0800334 memset(&vfd->class_dev, 0x00, sizeof(vfd->class_dev));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 if (vfd->dev)
336 vfd->class_dev.dev = vfd->dev;
337 vfd->class_dev.class = &video_class;
Michael Krufky50c25ff2006-01-09 15:25:34 -0200338 vfd->class_dev.devt = MKDEV(VIDEO_MAJOR, vfd->minor);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 strlcpy(vfd->class_dev.class_id, vfd->devfs_name + 4, BUS_ID_SIZE);
340 class_device_register(&vfd->class_dev);
341 class_device_create_file(&vfd->class_dev,
Michael Krufky50c25ff2006-01-09 15:25:34 -0200342 &class_device_attr_name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343
Mauro Carvalho Chehabd21838d2006-01-09 15:25:21 -0200344#if 1
345 /* needed until all drivers are fixed */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 if (!vfd->release)
347 printk(KERN_WARNING "videodev: \"%s\" has no release callback. "
348 "Please fix your driver for proper sysfs support, see "
349 "http://lwn.net/Articles/36850/\n", vfd->name);
350#endif
351 return 0;
352}
353
354/**
355 * video_unregister_device - unregister a video4linux device
356 * @vfd: the device to unregister
357 *
358 * This unregisters the passed device and deassigns the minor
359 * number. Future open calls will be met with errors.
360 */
Sigmund Augdal Helberg938606b2005-12-01 00:51:19 -0800361
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362void video_unregister_device(struct video_device *vfd)
363{
Ingo Molnar1e4baed2006-01-15 07:52:23 -0200364 mutex_lock(&videodev_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365 if(video_device[vfd->minor]!=vfd)
366 panic("videodev: bad unregister");
367
368 devfs_remove(vfd->devfs_name);
369 video_device[vfd->minor]=NULL;
370 class_device_unregister(&vfd->class_dev);
Ingo Molnar1e4baed2006-01-15 07:52:23 -0200371 mutex_unlock(&videodev_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372}
373
374
375static struct file_operations video_fops=
376{
377 .owner = THIS_MODULE,
378 .llseek = no_llseek,
379 .open = video_open,
380};
381
382/*
383 * Initialise video for linux
384 */
Sigmund Augdal Helberg938606b2005-12-01 00:51:19 -0800385
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386static int __init videodev_init(void)
387{
388 int ret;
389
390 printk(KERN_INFO "Linux video capture interface: v1.00\n");
391 if (register_chrdev(VIDEO_MAJOR, VIDEO_NAME, &video_fops)) {
392 printk(KERN_WARNING "video_dev: unable to get major %d\n", VIDEO_MAJOR);
393 return -EIO;
394 }
395
396 ret = class_register(&video_class);
397 if (ret < 0) {
398 unregister_chrdev(VIDEO_MAJOR, VIDEO_NAME);
399 printk(KERN_WARNING "video_dev: class_register failed\n");
400 return -EIO;
401 }
402
403 return 0;
404}
405
406static void __exit videodev_exit(void)
407{
408 class_unregister(&video_class);
409 unregister_chrdev(VIDEO_MAJOR, VIDEO_NAME);
410}
411
412module_init(videodev_init)
413module_exit(videodev_exit)
414
415EXPORT_SYMBOL(video_register_device);
416EXPORT_SYMBOL(video_unregister_device);
417EXPORT_SYMBOL(video_devdata);
418EXPORT_SYMBOL(video_usercopy);
419EXPORT_SYMBOL(video_exclusive_open);
420EXPORT_SYMBOL(video_exclusive_release);
421EXPORT_SYMBOL(video_device_alloc);
422EXPORT_SYMBOL(video_device_release);
423
424MODULE_AUTHOR("Alan Cox");
425MODULE_DESCRIPTION("Device registrar for Video4Linux drivers");
426MODULE_LICENSE("GPL");
427
428
429/*
430 * Local variables:
431 * c-basic-offset: 8
432 * End:
433 */