]>
Commit | Line | Data |
---|---|---|
27a5e6d3 HV |
1 | /* |
2 | * Video capture interface for Linux version 2 | |
3 | * | |
4 | * A generic video device interface for the LINUX operating system | |
5 | * using a set of device structures/vectors for low level operations. | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
11 | * | |
12 | * Authors: Alan Cox, <alan@redhat.com> (version 1) | |
13 | * Mauro Carvalho Chehab <mchehab@infradead.org> (version 2) | |
14 | * | |
15 | * Fixes: 20000516 Claudio Matsuoka <claudio@conectiva.com> | |
16 | * - Added procfs support | |
17 | */ | |
18 | ||
19 | #include <linux/module.h> | |
20 | #include <linux/types.h> | |
21 | #include <linux/kernel.h> | |
22 | #include <linux/mm.h> | |
23 | #include <linux/string.h> | |
24 | #include <linux/errno.h> | |
25 | #include <linux/init.h> | |
26 | #include <linux/kmod.h> | |
27 | #include <linux/slab.h> | |
28 | #include <linux/smp_lock.h> | |
29 | #include <asm/uaccess.h> | |
30 | #include <asm/system.h> | |
31 | ||
32 | #include <media/v4l2-common.h> | |
33 | ||
34 | #define VIDEO_NUM_DEVICES 256 | |
35 | #define VIDEO_NAME "video4linux" | |
36 | ||
37 | /* | |
38 | * sysfs stuff | |
39 | */ | |
40 | ||
41 | static ssize_t show_index(struct device *cd, | |
42 | struct device_attribute *attr, char *buf) | |
43 | { | |
22a04f10 | 44 | struct video_device *vfd = container_of(cd, struct video_device, dev); |
27a5e6d3 HV |
45 | return sprintf(buf, "%i\n", vfd->index); |
46 | } | |
47 | ||
48 | static ssize_t show_name(struct device *cd, | |
49 | struct device_attribute *attr, char *buf) | |
50 | { | |
22a04f10 | 51 | struct video_device *vfd = container_of(cd, struct video_device, dev); |
27a5e6d3 HV |
52 | return sprintf(buf, "%.*s\n", (int)sizeof(vfd->name), vfd->name); |
53 | } | |
54 | ||
55 | static struct device_attribute video_device_attrs[] = { | |
56 | __ATTR(name, S_IRUGO, show_name, NULL), | |
57 | __ATTR(index, S_IRUGO, show_index, NULL), | |
58 | __ATTR_NULL | |
59 | }; | |
60 | ||
61 | struct video_device *video_device_alloc(void) | |
62 | { | |
63 | struct video_device *vfd; | |
64 | ||
65 | vfd = kzalloc(sizeof(*vfd), GFP_KERNEL); | |
66 | return vfd; | |
67 | } | |
68 | EXPORT_SYMBOL(video_device_alloc); | |
69 | ||
70 | void video_device_release(struct video_device *vfd) | |
71 | { | |
72 | kfree(vfd); | |
73 | } | |
74 | EXPORT_SYMBOL(video_device_release); | |
75 | ||
76 | static void video_release(struct device *cd) | |
77 | { | |
22a04f10 | 78 | struct video_device *vfd = container_of(cd, struct video_device, dev); |
27a5e6d3 HV |
79 | |
80 | #if 1 | |
81 | /* needed until all drivers are fixed */ | |
82 | if (!vfd->release) | |
83 | return; | |
84 | #endif | |
85 | vfd->release(vfd); | |
86 | } | |
87 | ||
88 | static struct class video_class = { | |
89 | .name = VIDEO_NAME, | |
90 | .dev_attrs = video_device_attrs, | |
91 | .dev_release = video_release, | |
92 | }; | |
93 | ||
94 | /* | |
95 | * Active devices | |
96 | */ | |
97 | ||
98 | static struct video_device *video_device[VIDEO_NUM_DEVICES]; | |
99 | static DEFINE_MUTEX(videodev_lock); | |
100 | ||
101 | struct video_device *video_devdata(struct file *file) | |
102 | { | |
103 | return video_device[iminor(file->f_path.dentry->d_inode)]; | |
104 | } | |
105 | EXPORT_SYMBOL(video_devdata); | |
106 | ||
107 | /* | |
108 | * Open a video device - FIXME: Obsoleted | |
109 | */ | |
110 | static int video_open(struct inode *inode, struct file *file) | |
111 | { | |
112 | unsigned int minor = iminor(inode); | |
113 | int err = 0; | |
114 | struct video_device *vfl; | |
115 | const struct file_operations *old_fops; | |
116 | ||
117 | if (minor >= VIDEO_NUM_DEVICES) | |
118 | return -ENODEV; | |
27a5e6d3 HV |
119 | mutex_lock(&videodev_lock); |
120 | vfl = video_device[minor]; | |
121 | if (vfl == NULL) { | |
122 | mutex_unlock(&videodev_lock); | |
123 | request_module("char-major-%d-%d", VIDEO_MAJOR, minor); | |
124 | mutex_lock(&videodev_lock); | |
125 | vfl = video_device[minor]; | |
126 | if (vfl == NULL) { | |
127 | mutex_unlock(&videodev_lock); | |
27a5e6d3 HV |
128 | return -ENODEV; |
129 | } | |
130 | } | |
131 | old_fops = file->f_op; | |
132 | file->f_op = fops_get(vfl->fops); | |
133 | if (file->f_op->open) | |
134 | err = file->f_op->open(inode, file); | |
135 | if (err) { | |
136 | fops_put(file->f_op); | |
137 | file->f_op = fops_get(old_fops); | |
138 | } | |
139 | fops_put(old_fops); | |
140 | mutex_unlock(&videodev_lock); | |
27a5e6d3 HV |
141 | return err; |
142 | } | |
143 | ||
27a5e6d3 HV |
144 | /** |
145 | * get_index - assign stream number based on parent device | |
146 | * @vdev: video_device to assign index number to, vdev->dev should be assigned | |
147 | * @num: -1 if auto assign, requested number otherwise | |
148 | * | |
149 | * | |
150 | * returns -ENFILE if num is already in use, a free index number if | |
151 | * successful. | |
152 | */ | |
153 | static int get_index(struct video_device *vdev, int num) | |
154 | { | |
155 | u32 used = 0; | |
156 | const int max_index = sizeof(used) * 8 - 1; | |
157 | int i; | |
158 | ||
159 | /* Currently a single v4l driver instance cannot create more than | |
160 | 32 devices. | |
161 | Increase to u64 or an array of u32 if more are needed. */ | |
162 | if (num > max_index) { | |
163 | printk(KERN_ERR "videodev: %s num is too large\n", __func__); | |
164 | return -EINVAL; | |
165 | } | |
166 | ||
167 | for (i = 0; i < VIDEO_NUM_DEVICES; i++) { | |
168 | if (video_device[i] != NULL && | |
169 | video_device[i] != vdev && | |
5e85e732 | 170 | video_device[i]->parent == vdev->parent) { |
27a5e6d3 HV |
171 | used |= 1 << video_device[i]->index; |
172 | } | |
173 | } | |
174 | ||
175 | if (num >= 0) { | |
176 | if (used & (1 << num)) | |
177 | return -ENFILE; | |
178 | return num; | |
179 | } | |
180 | ||
181 | i = ffz(used); | |
182 | return i > max_index ? -ENFILE : i; | |
183 | } | |
184 | ||
185 | static const struct file_operations video_fops; | |
186 | ||
187 | int video_register_device(struct video_device *vfd, int type, int nr) | |
188 | { | |
189 | return video_register_device_index(vfd, type, nr, -1); | |
190 | } | |
191 | EXPORT_SYMBOL(video_register_device); | |
192 | ||
193 | /** | |
edc9189c | 194 | * video_register_device_index - register video4linux devices |
27a5e6d3 HV |
195 | * @vfd: video device structure we want to register |
196 | * @type: type of device to register | |
197 | * @nr: which device number (0 == /dev/video0, 1 == /dev/video1, ... | |
198 | * -1 == first free) | |
edc9189c RD |
199 | * @index: stream number based on parent device; |
200 | * -1 if auto assign, requested number otherwise | |
27a5e6d3 HV |
201 | * |
202 | * The registration code assigns minor numbers based on the type | |
203 | * requested. -ENFILE is returned in all the device slots for this | |
204 | * category are full. If not then the minor field is set and the | |
205 | * driver initialize function is called (if non %NULL). | |
206 | * | |
207 | * Zero is returned on success. | |
208 | * | |
209 | * Valid types are | |
210 | * | |
211 | * %VFL_TYPE_GRABBER - A frame grabber | |
212 | * | |
213 | * %VFL_TYPE_VTX - A teletext device | |
214 | * | |
215 | * %VFL_TYPE_VBI - Vertical blank data (undecoded) | |
216 | * | |
217 | * %VFL_TYPE_RADIO - A radio card | |
218 | */ | |
219 | ||
220 | int video_register_device_index(struct video_device *vfd, int type, int nr, | |
221 | int index) | |
222 | { | |
223 | int i = 0; | |
224 | int base; | |
225 | int end; | |
226 | int ret; | |
227 | char *name_base; | |
228 | ||
ee7aa9f8 HK |
229 | if (vfd == NULL) |
230 | return -EINVAL; | |
231 | ||
f3b9f50e HK |
232 | if (vfd == NULL) |
233 | return -EINVAL; | |
234 | ||
27a5e6d3 HV |
235 | switch (type) { |
236 | case VFL_TYPE_GRABBER: | |
237 | base = MINOR_VFL_TYPE_GRABBER_MIN; | |
238 | end = MINOR_VFL_TYPE_GRABBER_MAX+1; | |
239 | name_base = "video"; | |
240 | break; | |
241 | case VFL_TYPE_VTX: | |
242 | base = MINOR_VFL_TYPE_VTX_MIN; | |
243 | end = MINOR_VFL_TYPE_VTX_MAX+1; | |
244 | name_base = "vtx"; | |
245 | break; | |
246 | case VFL_TYPE_VBI: | |
247 | base = MINOR_VFL_TYPE_VBI_MIN; | |
248 | end = MINOR_VFL_TYPE_VBI_MAX+1; | |
249 | name_base = "vbi"; | |
250 | break; | |
251 | case VFL_TYPE_RADIO: | |
252 | base = MINOR_VFL_TYPE_RADIO_MIN; | |
253 | end = MINOR_VFL_TYPE_RADIO_MAX+1; | |
254 | name_base = "radio"; | |
255 | break; | |
256 | default: | |
257 | printk(KERN_ERR "%s called with unknown type: %d\n", | |
258 | __func__, type); | |
46f2c21c | 259 | return -EINVAL; |
27a5e6d3 HV |
260 | } |
261 | ||
262 | /* pick a minor number */ | |
263 | mutex_lock(&videodev_lock); | |
264 | if (nr >= 0 && nr < end-base) { | |
265 | /* use the one the driver asked for */ | |
266 | i = base + nr; | |
267 | if (NULL != video_device[i]) { | |
268 | mutex_unlock(&videodev_lock); | |
269 | return -ENFILE; | |
270 | } | |
271 | } else { | |
272 | /* use first free */ | |
273 | for (i = base; i < end; i++) | |
274 | if (NULL == video_device[i]) | |
275 | break; | |
276 | if (i == end) { | |
277 | mutex_unlock(&videodev_lock); | |
278 | return -ENFILE; | |
279 | } | |
280 | } | |
281 | video_device[i] = vfd; | |
0ea6bc8d | 282 | vfd->vfl_type = type; |
27a5e6d3 HV |
283 | vfd->minor = i; |
284 | ||
285 | ret = get_index(vfd, index); | |
286 | vfd->index = ret; | |
287 | ||
288 | mutex_unlock(&videodev_lock); | |
289 | ||
290 | if (ret < 0) { | |
291 | printk(KERN_ERR "%s: get_index failed\n", __func__); | |
292 | goto fail_minor; | |
293 | } | |
294 | ||
27a5e6d3 | 295 | /* sysfs class */ |
22a04f10 HV |
296 | memset(&vfd->dev, 0x00, sizeof(vfd->dev)); |
297 | vfd->dev.class = &video_class; | |
298 | vfd->dev.devt = MKDEV(VIDEO_MAJOR, vfd->minor); | |
5e85e732 | 299 | if (vfd->parent) |
22a04f10 HV |
300 | vfd->dev.parent = vfd->parent; |
301 | sprintf(vfd->dev.bus_id, "%s%d", name_base, i - base); | |
302 | ret = device_register(&vfd->dev); | |
27a5e6d3 HV |
303 | if (ret < 0) { |
304 | printk(KERN_ERR "%s: device_register failed\n", __func__); | |
305 | goto fail_minor; | |
306 | } | |
307 | ||
308 | #if 1 | |
309 | /* needed until all drivers are fixed */ | |
310 | if (!vfd->release) | |
311 | printk(KERN_WARNING "videodev: \"%s\" has no release callback. " | |
312 | "Please fix your driver for proper sysfs support, see " | |
313 | "http://lwn.net/Articles/36850/\n", vfd->name); | |
314 | #endif | |
315 | return 0; | |
316 | ||
317 | fail_minor: | |
318 | mutex_lock(&videodev_lock); | |
319 | video_device[vfd->minor] = NULL; | |
320 | vfd->minor = -1; | |
321 | mutex_unlock(&videodev_lock); | |
322 | return ret; | |
323 | } | |
324 | EXPORT_SYMBOL(video_register_device_index); | |
325 | ||
326 | /** | |
327 | * video_unregister_device - unregister a video4linux device | |
328 | * @vfd: the device to unregister | |
329 | * | |
330 | * This unregisters the passed device and deassigns the minor | |
331 | * number. Future open calls will be met with errors. | |
332 | */ | |
333 | ||
334 | void video_unregister_device(struct video_device *vfd) | |
335 | { | |
336 | mutex_lock(&videodev_lock); | |
337 | if (video_device[vfd->minor] != vfd) | |
338 | panic("videodev: bad unregister"); | |
339 | ||
340 | video_device[vfd->minor] = NULL; | |
22a04f10 | 341 | device_unregister(&vfd->dev); |
27a5e6d3 HV |
342 | mutex_unlock(&videodev_lock); |
343 | } | |
344 | EXPORT_SYMBOL(video_unregister_device); | |
345 | ||
346 | /* | |
347 | * Video fs operations | |
348 | */ | |
349 | static const struct file_operations video_fops = { | |
350 | .owner = THIS_MODULE, | |
351 | .llseek = no_llseek, | |
352 | .open = video_open, | |
353 | }; | |
354 | ||
355 | /* | |
356 | * Initialise video for linux | |
357 | */ | |
358 | ||
359 | static int __init videodev_init(void) | |
360 | { | |
361 | int ret; | |
362 | ||
363 | printk(KERN_INFO "Linux video capture interface: v2.00\n"); | |
364 | if (register_chrdev(VIDEO_MAJOR, VIDEO_NAME, &video_fops)) { | |
365 | printk(KERN_WARNING "video_dev: unable to get major %d\n", VIDEO_MAJOR); | |
366 | return -EIO; | |
367 | } | |
368 | ||
369 | ret = class_register(&video_class); | |
370 | if (ret < 0) { | |
371 | unregister_chrdev(VIDEO_MAJOR, VIDEO_NAME); | |
372 | printk(KERN_WARNING "video_dev: class_register failed\n"); | |
373 | return -EIO; | |
374 | } | |
375 | ||
376 | return 0; | |
377 | } | |
378 | ||
379 | static void __exit videodev_exit(void) | |
380 | { | |
381 | class_unregister(&video_class); | |
382 | unregister_chrdev(VIDEO_MAJOR, VIDEO_NAME); | |
383 | } | |
384 | ||
385 | module_init(videodev_init) | |
386 | module_exit(videodev_exit) | |
387 | ||
388 | MODULE_AUTHOR("Alan Cox, Mauro Carvalho Chehab <mchehab@infradead.org>"); | |
389 | MODULE_DESCRIPTION("Device registrar for Video4Linux drivers v2"); | |
390 | MODULE_LICENSE("GPL"); | |
391 | ||
392 | ||
393 | /* | |
394 | * Local variables: | |
395 | * c-basic-offset: 8 | |
396 | * End: | |
397 | */ |