Commit | Line | Data |
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1da177e4 LT |
1 | /* |
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> | |
32 | #include <asm/semaphore.h> | |
33 | ||
34 | #include <linux/videodev.h> | |
35 | ||
36 | #define VIDEO_NUM_DEVICES 256 | |
37 | #define VIDEO_NAME "video4linux" | |
38 | ||
39 | /* | |
40 | * sysfs stuff | |
41 | */ | |
42 | ||
43 | static ssize_t show_name(struct class_device *cd, char *buf) | |
44 | { | |
45 | struct video_device *vfd = container_of(cd, struct video_device, class_dev); | |
46 | return sprintf(buf,"%.*s\n",(int)sizeof(vfd->name),vfd->name); | |
47 | } | |
48 | ||
49 | static CLASS_DEVICE_ATTR(name, S_IRUGO, show_name, NULL); | |
50 | ||
51 | struct video_device *video_device_alloc(void) | |
52 | { | |
53 | struct video_device *vfd; | |
54 | ||
7408187d | 55 | vfd = kzalloc(sizeof(*vfd),GFP_KERNEL); |
1da177e4 LT |
56 | return vfd; |
57 | } | |
58 | ||
59 | void video_device_release(struct video_device *vfd) | |
60 | { | |
61 | kfree(vfd); | |
62 | } | |
63 | ||
64 | static void video_release(struct class_device *cd) | |
65 | { | |
66 | struct video_device *vfd = container_of(cd, struct video_device, class_dev); | |
67 | ||
d21838dd | 68 | #if 1 |
50c25fff | 69 | /* needed until all drivers are fixed */ |
1da177e4 LT |
70 | if (!vfd->release) |
71 | return; | |
72 | #endif | |
73 | vfd->release(vfd); | |
74 | } | |
75 | ||
76 | static struct class video_class = { | |
938606b0 | 77 | .name = VIDEO_NAME, |
1da177e4 LT |
78 | .release = video_release, |
79 | }; | |
80 | ||
81 | /* | |
938606b0 | 82 | * Active devices |
1da177e4 | 83 | */ |
938606b0 | 84 | |
1da177e4 LT |
85 | static struct video_device *video_device[VIDEO_NUM_DEVICES]; |
86 | static DECLARE_MUTEX(videodev_lock); | |
87 | ||
88 | struct video_device* video_devdata(struct file *file) | |
89 | { | |
90 | return video_device[iminor(file->f_dentry->d_inode)]; | |
91 | } | |
92 | ||
93 | /* | |
94 | * Open a video device. | |
95 | */ | |
96 | static int video_open(struct inode *inode, struct file *file) | |
97 | { | |
98 | unsigned int minor = iminor(inode); | |
99 | int err = 0; | |
100 | struct video_device *vfl; | |
101 | struct file_operations *old_fops; | |
938606b0 | 102 | |
1da177e4 LT |
103 | if(minor>=VIDEO_NUM_DEVICES) |
104 | return -ENODEV; | |
105 | down(&videodev_lock); | |
106 | vfl=video_device[minor]; | |
107 | if(vfl==NULL) { | |
108 | up(&videodev_lock); | |
109 | request_module("char-major-%d-%d", VIDEO_MAJOR, minor); | |
110 | down(&videodev_lock); | |
111 | vfl=video_device[minor]; | |
112 | if (vfl==NULL) { | |
113 | up(&videodev_lock); | |
114 | return -ENODEV; | |
115 | } | |
116 | } | |
117 | old_fops = file->f_op; | |
118 | file->f_op = fops_get(vfl->fops); | |
119 | if(file->f_op->open) | |
120 | err = file->f_op->open(inode,file); | |
121 | if (err) { | |
122 | fops_put(file->f_op); | |
123 | file->f_op = fops_get(old_fops); | |
124 | } | |
125 | fops_put(old_fops); | |
126 | up(&videodev_lock); | |
127 | return err; | |
128 | } | |
129 | ||
130 | /* | |
131 | * helper function -- handles userspace copying for ioctl arguments | |
132 | */ | |
133 | ||
134 | static unsigned int | |
135 | video_fix_command(unsigned int cmd) | |
136 | { | |
137 | switch (cmd) { | |
138 | case VIDIOC_OVERLAY_OLD: | |
139 | cmd = VIDIOC_OVERLAY; | |
140 | break; | |
141 | case VIDIOC_S_PARM_OLD: | |
142 | cmd = VIDIOC_S_PARM; | |
143 | break; | |
144 | case VIDIOC_S_CTRL_OLD: | |
145 | cmd = VIDIOC_S_CTRL; | |
146 | break; | |
147 | case VIDIOC_G_AUDIO_OLD: | |
148 | cmd = VIDIOC_G_AUDIO; | |
149 | break; | |
150 | case VIDIOC_G_AUDOUT_OLD: | |
151 | cmd = VIDIOC_G_AUDOUT; | |
152 | break; | |
153 | case VIDIOC_CROPCAP_OLD: | |
154 | cmd = VIDIOC_CROPCAP; | |
155 | break; | |
156 | } | |
157 | return cmd; | |
158 | } | |
159 | ||
160 | int | |
161 | video_usercopy(struct inode *inode, struct file *file, | |
162 | unsigned int cmd, unsigned long arg, | |
163 | int (*func)(struct inode *inode, struct file *file, | |
164 | unsigned int cmd, void *arg)) | |
165 | { | |
166 | char sbuf[128]; | |
167 | void *mbuf = NULL; | |
168 | void *parg = NULL; | |
169 | int err = -EINVAL; | |
170 | ||
171 | cmd = video_fix_command(cmd); | |
172 | ||
173 | /* Copy arguments into temp kernel buffer */ | |
174 | switch (_IOC_DIR(cmd)) { | |
175 | case _IOC_NONE: | |
176 | parg = NULL; | |
177 | break; | |
178 | case _IOC_READ: | |
179 | case _IOC_WRITE: | |
180 | case (_IOC_WRITE | _IOC_READ): | |
181 | if (_IOC_SIZE(cmd) <= sizeof(sbuf)) { | |
182 | parg = sbuf; | |
183 | } else { | |
184 | /* too big to allocate from stack */ | |
185 | mbuf = kmalloc(_IOC_SIZE(cmd),GFP_KERNEL); | |
186 | if (NULL == mbuf) | |
187 | return -ENOMEM; | |
188 | parg = mbuf; | |
189 | } | |
938606b0 | 190 | |
1da177e4 LT |
191 | err = -EFAULT; |
192 | if (_IOC_DIR(cmd) & _IOC_WRITE) | |
193 | if (copy_from_user(parg, (void __user *)arg, _IOC_SIZE(cmd))) | |
194 | goto out; | |
195 | break; | |
196 | } | |
197 | ||
198 | /* call driver */ | |
199 | err = func(inode, file, cmd, parg); | |
200 | if (err == -ENOIOCTLCMD) | |
201 | err = -EINVAL; | |
202 | if (err < 0) | |
203 | goto out; | |
204 | ||
205 | /* Copy results into user buffer */ | |
206 | switch (_IOC_DIR(cmd)) | |
207 | { | |
208 | case _IOC_READ: | |
209 | case (_IOC_WRITE | _IOC_READ): | |
210 | if (copy_to_user((void __user *)arg, parg, _IOC_SIZE(cmd))) | |
211 | err = -EFAULT; | |
212 | break; | |
213 | } | |
214 | ||
215 | out: | |
2ea75330 | 216 | kfree(mbuf); |
1da177e4 LT |
217 | return err; |
218 | } | |
219 | ||
220 | /* | |
221 | * open/release helper functions -- handle exclusive opens | |
222 | */ | |
223 | int video_exclusive_open(struct inode *inode, struct file *file) | |
224 | { | |
225 | struct video_device *vfl = video_devdata(file); | |
226 | int retval = 0; | |
227 | ||
228 | down(&vfl->lock); | |
229 | if (vfl->users) { | |
230 | retval = -EBUSY; | |
231 | } else { | |
232 | vfl->users++; | |
233 | } | |
234 | up(&vfl->lock); | |
235 | return retval; | |
236 | } | |
237 | ||
238 | int video_exclusive_release(struct inode *inode, struct file *file) | |
239 | { | |
240 | struct video_device *vfl = video_devdata(file); | |
938606b0 | 241 | |
1da177e4 LT |
242 | vfl->users--; |
243 | return 0; | |
244 | } | |
245 | ||
246 | static struct file_operations video_fops; | |
247 | ||
248 | /** | |
249 | * video_register_device - register video4linux devices | |
250 | * @vfd: video device structure we want to register | |
251 | * @type: type of device to register | |
252 | * @nr: which device number (0 == /dev/video0, 1 == /dev/video1, ... | |
253 | * -1 == first free) | |
938606b0 | 254 | * |
1da177e4 LT |
255 | * The registration code assigns minor numbers based on the type |
256 | * requested. -ENFILE is returned in all the device slots for this | |
257 | * category are full. If not then the minor field is set and the | |
258 | * driver initialize function is called (if non %NULL). | |
259 | * | |
260 | * Zero is returned on success. | |
261 | * | |
262 | * Valid types are | |
263 | * | |
264 | * %VFL_TYPE_GRABBER - A frame grabber | |
265 | * | |
266 | * %VFL_TYPE_VTX - A teletext device | |
267 | * | |
268 | * %VFL_TYPE_VBI - Vertical blank data (undecoded) | |
269 | * | |
938606b0 | 270 | * %VFL_TYPE_RADIO - A radio card |
1da177e4 LT |
271 | */ |
272 | ||
273 | int video_register_device(struct video_device *vfd, int type, int nr) | |
274 | { | |
275 | int i=0; | |
276 | int base; | |
277 | int end; | |
278 | char *name_base; | |
938606b0 | 279 | |
1da177e4 LT |
280 | switch(type) |
281 | { | |
282 | case VFL_TYPE_GRABBER: | |
283 | base=0; | |
284 | end=64; | |
285 | name_base = "video"; | |
286 | break; | |
287 | case VFL_TYPE_VTX: | |
288 | base=192; | |
289 | end=224; | |
290 | name_base = "vtx"; | |
291 | break; | |
292 | case VFL_TYPE_VBI: | |
293 | base=224; | |
938606b0 | 294 | end=256; |
1da177e4 LT |
295 | name_base = "vbi"; |
296 | break; | |
297 | case VFL_TYPE_RADIO: | |
298 | base=64; | |
299 | end=128; | |
300 | name_base = "radio"; | |
301 | break; | |
302 | default: | |
303 | return -1; | |
304 | } | |
305 | ||
306 | /* pick a minor number */ | |
307 | down(&videodev_lock); | |
308 | if (nr >= 0 && nr < end-base) { | |
309 | /* use the one the driver asked for */ | |
310 | i = base+nr; | |
311 | if (NULL != video_device[i]) { | |
312 | up(&videodev_lock); | |
313 | return -ENFILE; | |
314 | } | |
315 | } else { | |
316 | /* use first free */ | |
317 | for(i=base;i<end;i++) | |
318 | if (NULL == video_device[i]) | |
319 | break; | |
320 | if (i == end) { | |
321 | up(&videodev_lock); | |
322 | return -ENFILE; | |
323 | } | |
324 | } | |
325 | video_device[i]=vfd; | |
326 | vfd->minor=i; | |
327 | up(&videodev_lock); | |
328 | ||
329 | sprintf(vfd->devfs_name, "v4l/%s%d", name_base, i - base); | |
330 | devfs_mk_cdev(MKDEV(VIDEO_MAJOR, vfd->minor), | |
331 | S_IFCHR | S_IRUSR | S_IWUSR, vfd->devfs_name); | |
332 | init_MUTEX(&vfd->lock); | |
333 | ||
334 | /* sysfs class */ | |
938606b0 | 335 | memset(&vfd->class_dev, 0x00, sizeof(vfd->class_dev)); |
1da177e4 LT |
336 | if (vfd->dev) |
337 | vfd->class_dev.dev = vfd->dev; | |
338 | vfd->class_dev.class = &video_class; | |
50c25fff | 339 | vfd->class_dev.devt = MKDEV(VIDEO_MAJOR, vfd->minor); |
1da177e4 LT |
340 | strlcpy(vfd->class_dev.class_id, vfd->devfs_name + 4, BUS_ID_SIZE); |
341 | class_device_register(&vfd->class_dev); | |
342 | class_device_create_file(&vfd->class_dev, | |
50c25fff | 343 | &class_device_attr_name); |
1da177e4 | 344 | |
d21838dd MCC |
345 | #if 1 |
346 | /* needed until all drivers are fixed */ | |
1da177e4 LT |
347 | if (!vfd->release) |
348 | printk(KERN_WARNING "videodev: \"%s\" has no release callback. " | |
349 | "Please fix your driver for proper sysfs support, see " | |
350 | "http://lwn.net/Articles/36850/\n", vfd->name); | |
351 | #endif | |
352 | return 0; | |
353 | } | |
354 | ||
355 | /** | |
356 | * video_unregister_device - unregister a video4linux device | |
357 | * @vfd: the device to unregister | |
358 | * | |
359 | * This unregisters the passed device and deassigns the minor | |
360 | * number. Future open calls will be met with errors. | |
361 | */ | |
938606b0 | 362 | |
1da177e4 LT |
363 | void video_unregister_device(struct video_device *vfd) |
364 | { | |
365 | down(&videodev_lock); | |
366 | if(video_device[vfd->minor]!=vfd) | |
367 | panic("videodev: bad unregister"); | |
368 | ||
369 | devfs_remove(vfd->devfs_name); | |
370 | video_device[vfd->minor]=NULL; | |
371 | class_device_unregister(&vfd->class_dev); | |
372 | up(&videodev_lock); | |
373 | } | |
374 | ||
375 | ||
376 | static struct file_operations video_fops= | |
377 | { | |
378 | .owner = THIS_MODULE, | |
379 | .llseek = no_llseek, | |
380 | .open = video_open, | |
381 | }; | |
382 | ||
383 | /* | |
384 | * Initialise video for linux | |
385 | */ | |
938606b0 | 386 | |
1da177e4 LT |
387 | static int __init videodev_init(void) |
388 | { | |
389 | int ret; | |
390 | ||
391 | printk(KERN_INFO "Linux video capture interface: v1.00\n"); | |
392 | if (register_chrdev(VIDEO_MAJOR, VIDEO_NAME, &video_fops)) { | |
393 | printk(KERN_WARNING "video_dev: unable to get major %d\n", VIDEO_MAJOR); | |
394 | return -EIO; | |
395 | } | |
396 | ||
397 | ret = class_register(&video_class); | |
398 | if (ret < 0) { | |
399 | unregister_chrdev(VIDEO_MAJOR, VIDEO_NAME); | |
400 | printk(KERN_WARNING "video_dev: class_register failed\n"); | |
401 | return -EIO; | |
402 | } | |
403 | ||
404 | return 0; | |
405 | } | |
406 | ||
407 | static void __exit videodev_exit(void) | |
408 | { | |
409 | class_unregister(&video_class); | |
410 | unregister_chrdev(VIDEO_MAJOR, VIDEO_NAME); | |
411 | } | |
412 | ||
413 | module_init(videodev_init) | |
414 | module_exit(videodev_exit) | |
415 | ||
416 | EXPORT_SYMBOL(video_register_device); | |
417 | EXPORT_SYMBOL(video_unregister_device); | |
418 | EXPORT_SYMBOL(video_devdata); | |
419 | EXPORT_SYMBOL(video_usercopy); | |
420 | EXPORT_SYMBOL(video_exclusive_open); | |
421 | EXPORT_SYMBOL(video_exclusive_release); | |
422 | EXPORT_SYMBOL(video_device_alloc); | |
423 | EXPORT_SYMBOL(video_device_release); | |
424 | ||
425 | MODULE_AUTHOR("Alan Cox"); | |
426 | MODULE_DESCRIPTION("Device registrar for Video4Linux drivers"); | |
427 | MODULE_LICENSE("GPL"); | |
428 | ||
429 | ||
430 | /* | |
431 | * Local variables: | |
432 | * c-basic-offset: 8 | |
433 | * End: | |
434 | */ |