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1da177e4 LT |
1 | /* |
2 | * VIDEO MOTION CODECs internal API for video devices | |
3 | * | |
4 | * Interface for MJPEG (and maybe later MPEG/WAVELETS) codec's | |
5 | * bound to a master device. | |
6 | * | |
7 | * (c) 2002 Wolfgang Scherr <scherr@net4you.at> | |
8 | * | |
9 | * $Id: videocodec.c,v 1.1.2.8 2003/03/29 07:16:04 rbultje Exp $ | |
10 | * | |
11 | * ------------------------------------------------------------------------ | |
12 | * | |
13 | * This program is free software; you can redistribute it and/or modify | |
14 | * it under the terms of the GNU General Public License as published by | |
15 | * the Free Software Foundation; either version 2 of the License, or | |
16 | * (at your option) any later version. | |
17 | * | |
18 | * This program is distributed in the hope that it will be useful, | |
19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
21 | * GNU General Public License for more details. | |
22 | * | |
23 | * You should have received a copy of the GNU General Public License | |
24 | * along with this program; if not, write to the Free Software | |
25 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
26 | * | |
27 | * ------------------------------------------------------------------------ | |
28 | */ | |
29 | ||
30 | #define VIDEOCODEC_VERSION "v0.2" | |
31 | ||
32 | #include <linux/kernel.h> | |
33 | #include <linux/module.h> | |
34 | #include <linux/init.h> | |
35 | #include <linux/types.h> | |
36 | #include <linux/slab.h> | |
37 | ||
38 | // kernel config is here (procfs flag) | |
1da177e4 LT |
39 | |
40 | #ifdef CONFIG_PROC_FS | |
41 | #include <linux/proc_fs.h> | |
42 | #include <asm/uaccess.h> | |
43 | #endif | |
44 | ||
45 | #include "videocodec.h" | |
46 | ||
47 | static int debug = 0; | |
48 | module_param(debug, int, 0); | |
49 | MODULE_PARM_DESC(debug, "Debug level (0-4)"); | |
50 | ||
51 | #define dprintk(num, format, args...) \ | |
52 | do { \ | |
53 | if (debug >= num) \ | |
54 | printk(format, ##args); \ | |
55 | } while (0) | |
56 | ||
57 | struct attached_list { | |
58 | struct videocodec *codec; | |
59 | struct attached_list *next; | |
60 | }; | |
61 | ||
62 | struct codec_list { | |
63 | const struct videocodec *codec; | |
64 | int attached; | |
65 | struct attached_list *list; | |
66 | struct codec_list *next; | |
67 | }; | |
68 | ||
69 | static struct codec_list *codeclist_top = NULL; | |
70 | ||
71 | /* ================================================= */ | |
72 | /* function prototypes of the master/slave interface */ | |
73 | /* ================================================= */ | |
74 | ||
75 | struct videocodec * | |
76 | videocodec_attach (struct videocodec_master *master) | |
77 | { | |
78 | struct codec_list *h = codeclist_top; | |
79 | struct attached_list *a, *ptr; | |
80 | struct videocodec *codec; | |
81 | int res; | |
82 | ||
83 | if (!master) { | |
84 | dprintk(1, KERN_ERR "videocodec_attach: no data\n"); | |
85 | return NULL; | |
86 | } | |
87 | ||
88 | dprintk(2, | |
22c4a4e9 MCC |
89 | "videocodec_attach: '%s', flags %lx, magic %lx\n", |
90 | master->name, master->flags, master->magic); | |
1da177e4 LT |
91 | |
92 | if (!h) { | |
93 | dprintk(1, | |
94 | KERN_ERR | |
95 | "videocodec_attach: no device available\n"); | |
96 | return NULL; | |
97 | } | |
98 | ||
99 | while (h) { | |
100 | // attach only if the slave has at least the flags | |
101 | // expected by the master | |
102 | if ((master->flags & h->codec->flags) == master->flags) { | |
103 | dprintk(4, "videocodec_attach: try '%s'\n", | |
104 | h->codec->name); | |
105 | ||
106 | if (!try_module_get(h->codec->owner)) | |
107 | return NULL; | |
108 | ||
109 | codec = | |
110 | kmalloc(sizeof(struct videocodec), GFP_KERNEL); | |
111 | if (!codec) { | |
112 | dprintk(1, | |
113 | KERN_ERR | |
114 | "videocodec_attach: no mem\n"); | |
115 | goto out_module_put; | |
116 | } | |
117 | memcpy(codec, h->codec, sizeof(struct videocodec)); | |
118 | ||
119 | snprintf(codec->name, sizeof(codec->name), | |
120 | "%s[%d]", codec->name, h->attached); | |
121 | codec->master_data = master; | |
122 | res = codec->setup(codec); | |
123 | if (res == 0) { | |
124 | dprintk(3, "videocodec_attach '%s'\n", | |
125 | codec->name); | |
7408187d | 126 | ptr = kzalloc(sizeof(struct attached_list), GFP_KERNEL); |
1da177e4 LT |
127 | if (!ptr) { |
128 | dprintk(1, | |
129 | KERN_ERR | |
130 | "videocodec_attach: no memory\n"); | |
131 | goto out_kfree; | |
132 | } | |
1da177e4 LT |
133 | ptr->codec = codec; |
134 | ||
135 | a = h->list; | |
136 | if (!a) { | |
137 | h->list = ptr; | |
138 | dprintk(4, | |
139 | "videocodec: first element\n"); | |
140 | } else { | |
141 | while (a->next) | |
142 | a = a->next; // find end | |
143 | a->next = ptr; | |
144 | dprintk(4, | |
145 | "videocodec: in after '%s'\n", | |
146 | h->codec->name); | |
147 | } | |
148 | ||
149 | h->attached += 1; | |
150 | return codec; | |
151 | } else { | |
152 | kfree(codec); | |
153 | } | |
154 | } | |
155 | h = h->next; | |
156 | } | |
157 | ||
158 | dprintk(1, KERN_ERR "videocodec_attach: no codec found!\n"); | |
159 | return NULL; | |
160 | ||
161 | out_module_put: | |
162 | module_put(h->codec->owner); | |
163 | out_kfree: | |
164 | kfree(codec); | |
165 | return NULL; | |
166 | } | |
167 | ||
168 | int | |
169 | videocodec_detach (struct videocodec *codec) | |
170 | { | |
171 | struct codec_list *h = codeclist_top; | |
172 | struct attached_list *a, *prev; | |
173 | int res; | |
174 | ||
175 | if (!codec) { | |
176 | dprintk(1, KERN_ERR "videocodec_detach: no data\n"); | |
177 | return -EINVAL; | |
178 | } | |
179 | ||
180 | dprintk(2, | |
181 | "videocodec_detach: '%s', type: %x, flags %lx, magic %lx\n", | |
182 | codec->name, codec->type, codec->flags, codec->magic); | |
183 | ||
184 | if (!h) { | |
185 | dprintk(1, | |
186 | KERN_ERR "videocodec_detach: no device left...\n"); | |
187 | return -ENXIO; | |
188 | } | |
189 | ||
190 | while (h) { | |
191 | a = h->list; | |
192 | prev = NULL; | |
193 | while (a) { | |
194 | if (codec == a->codec) { | |
195 | res = a->codec->unset(a->codec); | |
196 | if (res >= 0) { | |
197 | dprintk(3, | |
198 | "videocodec_detach: '%s'\n", | |
199 | a->codec->name); | |
200 | a->codec->master_data = NULL; | |
201 | } else { | |
202 | dprintk(1, | |
203 | KERN_ERR | |
204 | "videocodec_detach: '%s'\n", | |
205 | a->codec->name); | |
206 | a->codec->master_data = NULL; | |
207 | } | |
208 | if (prev == NULL) { | |
209 | h->list = a->next; | |
210 | dprintk(4, | |
211 | "videocodec: delete first\n"); | |
212 | } else { | |
213 | prev->next = a->next; | |
214 | dprintk(4, | |
215 | "videocodec: delete middle\n"); | |
216 | } | |
217 | module_put(a->codec->owner); | |
218 | kfree(a->codec); | |
219 | kfree(a); | |
220 | h->attached -= 1; | |
221 | return 0; | |
222 | } | |
223 | prev = a; | |
224 | a = a->next; | |
225 | } | |
226 | h = h->next; | |
227 | } | |
228 | ||
229 | dprintk(1, KERN_ERR "videocodec_detach: given codec not found!\n"); | |
230 | return -EINVAL; | |
231 | } | |
232 | ||
233 | int | |
234 | videocodec_register (const struct videocodec *codec) | |
235 | { | |
236 | struct codec_list *ptr, *h = codeclist_top; | |
237 | ||
238 | if (!codec) { | |
239 | dprintk(1, KERN_ERR "videocodec_register: no data!\n"); | |
240 | return -EINVAL; | |
241 | } | |
242 | ||
243 | dprintk(2, | |
244 | "videocodec: register '%s', type: %x, flags %lx, magic %lx\n", | |
245 | codec->name, codec->type, codec->flags, codec->magic); | |
246 | ||
7408187d | 247 | ptr = kzalloc(sizeof(struct codec_list), GFP_KERNEL); |
1da177e4 LT |
248 | if (!ptr) { |
249 | dprintk(1, KERN_ERR "videocodec_register: no memory\n"); | |
250 | return -ENOMEM; | |
251 | } | |
1da177e4 LT |
252 | ptr->codec = codec; |
253 | ||
254 | if (!h) { | |
255 | codeclist_top = ptr; | |
256 | dprintk(4, "videocodec: hooked in as first element\n"); | |
257 | } else { | |
258 | while (h->next) | |
259 | h = h->next; // find the end | |
260 | h->next = ptr; | |
261 | dprintk(4, "videocodec: hooked in after '%s'\n", | |
262 | h->codec->name); | |
263 | } | |
264 | ||
265 | return 0; | |
266 | } | |
267 | ||
268 | int | |
269 | videocodec_unregister (const struct videocodec *codec) | |
270 | { | |
271 | struct codec_list *prev = NULL, *h = codeclist_top; | |
272 | ||
273 | if (!codec) { | |
274 | dprintk(1, KERN_ERR "videocodec_unregister: no data!\n"); | |
275 | return -EINVAL; | |
276 | } | |
277 | ||
278 | dprintk(2, | |
279 | "videocodec: unregister '%s', type: %x, flags %lx, magic %lx\n", | |
280 | codec->name, codec->type, codec->flags, codec->magic); | |
281 | ||
282 | if (!h) { | |
283 | dprintk(1, | |
284 | KERN_ERR | |
285 | "videocodec_unregister: no device left...\n"); | |
286 | return -ENXIO; | |
287 | } | |
288 | ||
289 | while (h) { | |
290 | if (codec == h->codec) { | |
291 | if (h->attached) { | |
292 | dprintk(1, | |
293 | KERN_ERR | |
294 | "videocodec: '%s' is used\n", | |
295 | h->codec->name); | |
296 | return -EBUSY; | |
297 | } | |
298 | dprintk(3, "videocodec: unregister '%s' is ok.\n", | |
299 | h->codec->name); | |
300 | if (prev == NULL) { | |
301 | codeclist_top = h->next; | |
302 | dprintk(4, | |
303 | "videocodec: delete first element\n"); | |
304 | } else { | |
305 | prev->next = h->next; | |
306 | dprintk(4, | |
307 | "videocodec: delete middle element\n"); | |
308 | } | |
309 | kfree(h); | |
310 | return 0; | |
311 | } | |
312 | prev = h; | |
313 | h = h->next; | |
314 | } | |
315 | ||
316 | dprintk(1, | |
317 | KERN_ERR | |
318 | "videocodec_unregister: given codec not found!\n"); | |
319 | return -EINVAL; | |
320 | } | |
321 | ||
322 | #ifdef CONFIG_PROC_FS | |
323 | /* ============ */ | |
324 | /* procfs stuff */ | |
325 | /* ============ */ | |
326 | ||
327 | static char *videocodec_buf = NULL; | |
328 | static int videocodec_bufsize = 0; | |
329 | ||
330 | static int | |
331 | videocodec_build_table (void) | |
332 | { | |
333 | struct codec_list *h = codeclist_top; | |
334 | struct attached_list *a; | |
335 | int i = 0, size; | |
336 | ||
337 | // sum up amount of slaves plus their attached masters | |
338 | while (h) { | |
339 | i += h->attached + 1; | |
340 | h = h->next; | |
341 | } | |
342 | #define LINESIZE 100 | |
343 | size = LINESIZE * (i + 1); | |
344 | ||
345 | dprintk(3, "videocodec_build table: %d entries, %d bytes\n", i, | |
346 | size); | |
347 | ||
2ea75330 | 348 | kfree(videocodec_buf); |
5cbded58 | 349 | videocodec_buf = kmalloc(size, GFP_KERNEL); |
1da177e4 | 350 | |
20ec811e AC |
351 | if (!videocodec_buf) |
352 | return 0; | |
353 | ||
1da177e4 LT |
354 | i = 0; |
355 | i += scnprintf(videocodec_buf + i, size - 1, | |
356 | "<S>lave or attached <M>aster name type flags magic "); | |
357 | i += scnprintf(videocodec_buf + i, size -i - 1, "(connected as)\n"); | |
358 | ||
359 | h = codeclist_top; | |
360 | while (h) { | |
361 | if (i > (size - LINESIZE)) | |
362 | break; // security check | |
363 | i += scnprintf(videocodec_buf + i, size -i -1, | |
364 | "S %32s %04x %08lx %08lx (TEMPLATE)\n", | |
365 | h->codec->name, h->codec->type, | |
366 | h->codec->flags, h->codec->magic); | |
367 | a = h->list; | |
368 | while (a) { | |
369 | if (i > (size - LINESIZE)) | |
370 | break; // security check | |
371 | i += scnprintf(videocodec_buf + i, size -i -1, | |
372 | "M %32s %04x %08lx %08lx (%s)\n", | |
373 | a->codec->master_data->name, | |
374 | a->codec->master_data->type, | |
375 | a->codec->master_data->flags, | |
376 | a->codec->master_data->magic, | |
377 | a->codec->name); | |
378 | a = a->next; | |
379 | } | |
380 | h = h->next; | |
381 | } | |
382 | ||
383 | return i; | |
384 | } | |
385 | ||
386 | //The definition: | |
387 | //typedef int (read_proc_t)(char *page, char **start, off_t off, | |
388 | // int count, int *eof, void *data); | |
389 | ||
390 | static int | |
391 | videocodec_info (char *buffer, | |
392 | char **buffer_location, | |
393 | off_t offset, | |
394 | int buffer_length, | |
395 | int *eof, | |
396 | void *data) | |
397 | { | |
398 | int size; | |
399 | ||
400 | dprintk(3, "videocodec_info: offset: %ld, len %d / size %d\n", | |
401 | offset, buffer_length, videocodec_bufsize); | |
402 | ||
403 | if (offset == 0) { | |
404 | videocodec_bufsize = videocodec_build_table(); | |
405 | } | |
406 | if ((offset < 0) || (offset >= videocodec_bufsize)) { | |
407 | dprintk(4, | |
408 | "videocodec_info: call delivers no result, return 0\n"); | |
409 | *eof = 1; | |
410 | return 0; | |
411 | } | |
412 | ||
413 | if (buffer_length < (videocodec_bufsize - offset)) { | |
414 | dprintk(4, "videocodec_info: %ld needed, %d got\n", | |
415 | videocodec_bufsize - offset, buffer_length); | |
416 | size = buffer_length; | |
417 | } else { | |
418 | dprintk(4, "videocodec_info: last reading of %ld bytes\n", | |
419 | videocodec_bufsize - offset); | |
420 | size = videocodec_bufsize - offset; | |
421 | *eof = 1; | |
422 | } | |
423 | ||
424 | memcpy(buffer, videocodec_buf + offset, size); | |
425 | /* doesn't work... */ | |
426 | /* copy_to_user(buffer, videocodec_buf+offset, size); */ | |
427 | /* *buffer_location = videocodec_buf+offset; */ | |
428 | ||
429 | return size; | |
430 | } | |
431 | #endif | |
432 | ||
433 | /* ===================== */ | |
434 | /* hook in driver module */ | |
435 | /* ===================== */ | |
436 | static int __init | |
437 | videocodec_init (void) | |
438 | { | |
439 | #ifdef CONFIG_PROC_FS | |
440 | static struct proc_dir_entry *videocodec_proc_entry; | |
441 | #endif | |
442 | ||
443 | printk(KERN_INFO "Linux video codec intermediate layer: %s\n", | |
444 | VIDEOCODEC_VERSION); | |
445 | ||
446 | #ifdef CONFIG_PROC_FS | |
447 | videocodec_buf = NULL; | |
448 | videocodec_bufsize = 0; | |
449 | ||
450 | videocodec_proc_entry = create_proc_entry("videocodecs", 0, NULL); | |
451 | if (videocodec_proc_entry) { | |
452 | videocodec_proc_entry->read_proc = videocodec_info; | |
453 | videocodec_proc_entry->write_proc = NULL; | |
454 | videocodec_proc_entry->data = NULL; | |
455 | videocodec_proc_entry->owner = THIS_MODULE; | |
456 | } else { | |
457 | dprintk(1, KERN_ERR "videocodec: can't init procfs.\n"); | |
458 | } | |
459 | #endif | |
460 | return 0; | |
461 | } | |
462 | ||
463 | static void __exit | |
464 | videocodec_exit (void) | |
465 | { | |
466 | #ifdef CONFIG_PROC_FS | |
467 | remove_proc_entry("videocodecs", NULL); | |
2ea75330 | 468 | kfree(videocodec_buf); |
1da177e4 LT |
469 | #endif |
470 | } | |
471 | ||
472 | EXPORT_SYMBOL(videocodec_attach); | |
473 | EXPORT_SYMBOL(videocodec_detach); | |
474 | EXPORT_SYMBOL(videocodec_register); | |
475 | EXPORT_SYMBOL(videocodec_unregister); | |
476 | ||
477 | module_init(videocodec_init); | |
478 | module_exit(videocodec_exit); | |
479 | ||
480 | MODULE_AUTHOR("Wolfgang Scherr <scherr@net4you.at>"); | |
481 | MODULE_DESCRIPTION("Intermediate API module for video codecs " | |
482 | VIDEOCODEC_VERSION); | |
483 | MODULE_LICENSE("GPL"); |