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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) | |
39 | #include <linux/config.h> | |
40 | ||
41 | #ifdef CONFIG_PROC_FS | |
42 | #include <linux/proc_fs.h> | |
43 | #include <asm/uaccess.h> | |
44 | #endif | |
45 | ||
46 | #include "videocodec.h" | |
47 | ||
48 | static int debug = 0; | |
49 | module_param(debug, int, 0); | |
50 | MODULE_PARM_DESC(debug, "Debug level (0-4)"); | |
51 | ||
52 | #define dprintk(num, format, args...) \ | |
53 | do { \ | |
54 | if (debug >= num) \ | |
55 | printk(format, ##args); \ | |
56 | } while (0) | |
57 | ||
58 | struct attached_list { | |
59 | struct videocodec *codec; | |
60 | struct attached_list *next; | |
61 | }; | |
62 | ||
63 | struct codec_list { | |
64 | const struct videocodec *codec; | |
65 | int attached; | |
66 | struct attached_list *list; | |
67 | struct codec_list *next; | |
68 | }; | |
69 | ||
70 | static struct codec_list *codeclist_top = NULL; | |
71 | ||
72 | /* ================================================= */ | |
73 | /* function prototypes of the master/slave interface */ | |
74 | /* ================================================= */ | |
75 | ||
76 | struct videocodec * | |
77 | videocodec_attach (struct videocodec_master *master) | |
78 | { | |
79 | struct codec_list *h = codeclist_top; | |
80 | struct attached_list *a, *ptr; | |
81 | struct videocodec *codec; | |
82 | int res; | |
83 | ||
84 | if (!master) { | |
85 | dprintk(1, KERN_ERR "videocodec_attach: no data\n"); | |
86 | return NULL; | |
87 | } | |
88 | ||
89 | dprintk(2, | |
90 | "videocodec_attach: '%s', type: %x, flags %lx, magic %lx\n", | |
91 | master->name, master->type, master->flags, master->magic); | |
92 | ||
93 | if (!h) { | |
94 | dprintk(1, | |
95 | KERN_ERR | |
96 | "videocodec_attach: no device available\n"); | |
97 | return NULL; | |
98 | } | |
99 | ||
100 | while (h) { | |
101 | // attach only if the slave has at least the flags | |
102 | // expected by the master | |
103 | if ((master->flags & h->codec->flags) == master->flags) { | |
104 | dprintk(4, "videocodec_attach: try '%s'\n", | |
105 | h->codec->name); | |
106 | ||
107 | if (!try_module_get(h->codec->owner)) | |
108 | return NULL; | |
109 | ||
110 | codec = | |
111 | kmalloc(sizeof(struct videocodec), GFP_KERNEL); | |
112 | if (!codec) { | |
113 | dprintk(1, | |
114 | KERN_ERR | |
115 | "videocodec_attach: no mem\n"); | |
116 | goto out_module_put; | |
117 | } | |
118 | memcpy(codec, h->codec, sizeof(struct videocodec)); | |
119 | ||
120 | snprintf(codec->name, sizeof(codec->name), | |
121 | "%s[%d]", codec->name, h->attached); | |
122 | codec->master_data = master; | |
123 | res = codec->setup(codec); | |
124 | if (res == 0) { | |
125 | dprintk(3, "videocodec_attach '%s'\n", | |
126 | codec->name); | |
127 | ptr = (struct attached_list *) | |
128 | kmalloc(sizeof(struct attached_list), | |
129 | GFP_KERNEL); | |
130 | if (!ptr) { | |
131 | dprintk(1, | |
132 | KERN_ERR | |
133 | "videocodec_attach: no memory\n"); | |
134 | goto out_kfree; | |
135 | } | |
136 | memset(ptr, 0, | |
137 | sizeof(struct attached_list)); | |
138 | ptr->codec = codec; | |
139 | ||
140 | a = h->list; | |
141 | if (!a) { | |
142 | h->list = ptr; | |
143 | dprintk(4, | |
144 | "videocodec: first element\n"); | |
145 | } else { | |
146 | while (a->next) | |
147 | a = a->next; // find end | |
148 | a->next = ptr; | |
149 | dprintk(4, | |
150 | "videocodec: in after '%s'\n", | |
151 | h->codec->name); | |
152 | } | |
153 | ||
154 | h->attached += 1; | |
155 | return codec; | |
156 | } else { | |
157 | kfree(codec); | |
158 | } | |
159 | } | |
160 | h = h->next; | |
161 | } | |
162 | ||
163 | dprintk(1, KERN_ERR "videocodec_attach: no codec found!\n"); | |
164 | return NULL; | |
165 | ||
166 | out_module_put: | |
167 | module_put(h->codec->owner); | |
168 | out_kfree: | |
169 | kfree(codec); | |
170 | return NULL; | |
171 | } | |
172 | ||
173 | int | |
174 | videocodec_detach (struct videocodec *codec) | |
175 | { | |
176 | struct codec_list *h = codeclist_top; | |
177 | struct attached_list *a, *prev; | |
178 | int res; | |
179 | ||
180 | if (!codec) { | |
181 | dprintk(1, KERN_ERR "videocodec_detach: no data\n"); | |
182 | return -EINVAL; | |
183 | } | |
184 | ||
185 | dprintk(2, | |
186 | "videocodec_detach: '%s', type: %x, flags %lx, magic %lx\n", | |
187 | codec->name, codec->type, codec->flags, codec->magic); | |
188 | ||
189 | if (!h) { | |
190 | dprintk(1, | |
191 | KERN_ERR "videocodec_detach: no device left...\n"); | |
192 | return -ENXIO; | |
193 | } | |
194 | ||
195 | while (h) { | |
196 | a = h->list; | |
197 | prev = NULL; | |
198 | while (a) { | |
199 | if (codec == a->codec) { | |
200 | res = a->codec->unset(a->codec); | |
201 | if (res >= 0) { | |
202 | dprintk(3, | |
203 | "videocodec_detach: '%s'\n", | |
204 | a->codec->name); | |
205 | a->codec->master_data = NULL; | |
206 | } else { | |
207 | dprintk(1, | |
208 | KERN_ERR | |
209 | "videocodec_detach: '%s'\n", | |
210 | a->codec->name); | |
211 | a->codec->master_data = NULL; | |
212 | } | |
213 | if (prev == NULL) { | |
214 | h->list = a->next; | |
215 | dprintk(4, | |
216 | "videocodec: delete first\n"); | |
217 | } else { | |
218 | prev->next = a->next; | |
219 | dprintk(4, | |
220 | "videocodec: delete middle\n"); | |
221 | } | |
222 | module_put(a->codec->owner); | |
223 | kfree(a->codec); | |
224 | kfree(a); | |
225 | h->attached -= 1; | |
226 | return 0; | |
227 | } | |
228 | prev = a; | |
229 | a = a->next; | |
230 | } | |
231 | h = h->next; | |
232 | } | |
233 | ||
234 | dprintk(1, KERN_ERR "videocodec_detach: given codec not found!\n"); | |
235 | return -EINVAL; | |
236 | } | |
237 | ||
238 | int | |
239 | videocodec_register (const struct videocodec *codec) | |
240 | { | |
241 | struct codec_list *ptr, *h = codeclist_top; | |
242 | ||
243 | if (!codec) { | |
244 | dprintk(1, KERN_ERR "videocodec_register: no data!\n"); | |
245 | return -EINVAL; | |
246 | } | |
247 | ||
248 | dprintk(2, | |
249 | "videocodec: register '%s', type: %x, flags %lx, magic %lx\n", | |
250 | codec->name, codec->type, codec->flags, codec->magic); | |
251 | ||
252 | ptr = | |
253 | (struct codec_list *) kmalloc(sizeof(struct codec_list), | |
254 | GFP_KERNEL); | |
255 | if (!ptr) { | |
256 | dprintk(1, KERN_ERR "videocodec_register: no memory\n"); | |
257 | return -ENOMEM; | |
258 | } | |
259 | memset(ptr, 0, sizeof(struct codec_list)); | |
260 | ptr->codec = codec; | |
261 | ||
262 | if (!h) { | |
263 | codeclist_top = ptr; | |
264 | dprintk(4, "videocodec: hooked in as first element\n"); | |
265 | } else { | |
266 | while (h->next) | |
267 | h = h->next; // find the end | |
268 | h->next = ptr; | |
269 | dprintk(4, "videocodec: hooked in after '%s'\n", | |
270 | h->codec->name); | |
271 | } | |
272 | ||
273 | return 0; | |
274 | } | |
275 | ||
276 | int | |
277 | videocodec_unregister (const struct videocodec *codec) | |
278 | { | |
279 | struct codec_list *prev = NULL, *h = codeclist_top; | |
280 | ||
281 | if (!codec) { | |
282 | dprintk(1, KERN_ERR "videocodec_unregister: no data!\n"); | |
283 | return -EINVAL; | |
284 | } | |
285 | ||
286 | dprintk(2, | |
287 | "videocodec: unregister '%s', type: %x, flags %lx, magic %lx\n", | |
288 | codec->name, codec->type, codec->flags, codec->magic); | |
289 | ||
290 | if (!h) { | |
291 | dprintk(1, | |
292 | KERN_ERR | |
293 | "videocodec_unregister: no device left...\n"); | |
294 | return -ENXIO; | |
295 | } | |
296 | ||
297 | while (h) { | |
298 | if (codec == h->codec) { | |
299 | if (h->attached) { | |
300 | dprintk(1, | |
301 | KERN_ERR | |
302 | "videocodec: '%s' is used\n", | |
303 | h->codec->name); | |
304 | return -EBUSY; | |
305 | } | |
306 | dprintk(3, "videocodec: unregister '%s' is ok.\n", | |
307 | h->codec->name); | |
308 | if (prev == NULL) { | |
309 | codeclist_top = h->next; | |
310 | dprintk(4, | |
311 | "videocodec: delete first element\n"); | |
312 | } else { | |
313 | prev->next = h->next; | |
314 | dprintk(4, | |
315 | "videocodec: delete middle element\n"); | |
316 | } | |
317 | kfree(h); | |
318 | return 0; | |
319 | } | |
320 | prev = h; | |
321 | h = h->next; | |
322 | } | |
323 | ||
324 | dprintk(1, | |
325 | KERN_ERR | |
326 | "videocodec_unregister: given codec not found!\n"); | |
327 | return -EINVAL; | |
328 | } | |
329 | ||
330 | #ifdef CONFIG_PROC_FS | |
331 | /* ============ */ | |
332 | /* procfs stuff */ | |
333 | /* ============ */ | |
334 | ||
335 | static char *videocodec_buf = NULL; | |
336 | static int videocodec_bufsize = 0; | |
337 | ||
338 | static int | |
339 | videocodec_build_table (void) | |
340 | { | |
341 | struct codec_list *h = codeclist_top; | |
342 | struct attached_list *a; | |
343 | int i = 0, size; | |
344 | ||
345 | // sum up amount of slaves plus their attached masters | |
346 | while (h) { | |
347 | i += h->attached + 1; | |
348 | h = h->next; | |
349 | } | |
350 | #define LINESIZE 100 | |
351 | size = LINESIZE * (i + 1); | |
352 | ||
353 | dprintk(3, "videocodec_build table: %d entries, %d bytes\n", i, | |
354 | size); | |
355 | ||
356 | if (videocodec_buf) | |
357 | kfree(videocodec_buf); | |
358 | videocodec_buf = (char *) kmalloc(size, GFP_KERNEL); | |
359 | ||
360 | i = 0; | |
361 | i += scnprintf(videocodec_buf + i, size - 1, | |
362 | "<S>lave or attached <M>aster name type flags magic "); | |
363 | i += scnprintf(videocodec_buf + i, size -i - 1, "(connected as)\n"); | |
364 | ||
365 | h = codeclist_top; | |
366 | while (h) { | |
367 | if (i > (size - LINESIZE)) | |
368 | break; // security check | |
369 | i += scnprintf(videocodec_buf + i, size -i -1, | |
370 | "S %32s %04x %08lx %08lx (TEMPLATE)\n", | |
371 | h->codec->name, h->codec->type, | |
372 | h->codec->flags, h->codec->magic); | |
373 | a = h->list; | |
374 | while (a) { | |
375 | if (i > (size - LINESIZE)) | |
376 | break; // security check | |
377 | i += scnprintf(videocodec_buf + i, size -i -1, | |
378 | "M %32s %04x %08lx %08lx (%s)\n", | |
379 | a->codec->master_data->name, | |
380 | a->codec->master_data->type, | |
381 | a->codec->master_data->flags, | |
382 | a->codec->master_data->magic, | |
383 | a->codec->name); | |
384 | a = a->next; | |
385 | } | |
386 | h = h->next; | |
387 | } | |
388 | ||
389 | return i; | |
390 | } | |
391 | ||
392 | //The definition: | |
393 | //typedef int (read_proc_t)(char *page, char **start, off_t off, | |
394 | // int count, int *eof, void *data); | |
395 | ||
396 | static int | |
397 | videocodec_info (char *buffer, | |
398 | char **buffer_location, | |
399 | off_t offset, | |
400 | int buffer_length, | |
401 | int *eof, | |
402 | void *data) | |
403 | { | |
404 | int size; | |
405 | ||
406 | dprintk(3, "videocodec_info: offset: %ld, len %d / size %d\n", | |
407 | offset, buffer_length, videocodec_bufsize); | |
408 | ||
409 | if (offset == 0) { | |
410 | videocodec_bufsize = videocodec_build_table(); | |
411 | } | |
412 | if ((offset < 0) || (offset >= videocodec_bufsize)) { | |
413 | dprintk(4, | |
414 | "videocodec_info: call delivers no result, return 0\n"); | |
415 | *eof = 1; | |
416 | return 0; | |
417 | } | |
418 | ||
419 | if (buffer_length < (videocodec_bufsize - offset)) { | |
420 | dprintk(4, "videocodec_info: %ld needed, %d got\n", | |
421 | videocodec_bufsize - offset, buffer_length); | |
422 | size = buffer_length; | |
423 | } else { | |
424 | dprintk(4, "videocodec_info: last reading of %ld bytes\n", | |
425 | videocodec_bufsize - offset); | |
426 | size = videocodec_bufsize - offset; | |
427 | *eof = 1; | |
428 | } | |
429 | ||
430 | memcpy(buffer, videocodec_buf + offset, size); | |
431 | /* doesn't work... */ | |
432 | /* copy_to_user(buffer, videocodec_buf+offset, size); */ | |
433 | /* *buffer_location = videocodec_buf+offset; */ | |
434 | ||
435 | return size; | |
436 | } | |
437 | #endif | |
438 | ||
439 | /* ===================== */ | |
440 | /* hook in driver module */ | |
441 | /* ===================== */ | |
442 | static int __init | |
443 | videocodec_init (void) | |
444 | { | |
445 | #ifdef CONFIG_PROC_FS | |
446 | static struct proc_dir_entry *videocodec_proc_entry; | |
447 | #endif | |
448 | ||
449 | printk(KERN_INFO "Linux video codec intermediate layer: %s\n", | |
450 | VIDEOCODEC_VERSION); | |
451 | ||
452 | #ifdef CONFIG_PROC_FS | |
453 | videocodec_buf = NULL; | |
454 | videocodec_bufsize = 0; | |
455 | ||
456 | videocodec_proc_entry = create_proc_entry("videocodecs", 0, NULL); | |
457 | if (videocodec_proc_entry) { | |
458 | videocodec_proc_entry->read_proc = videocodec_info; | |
459 | videocodec_proc_entry->write_proc = NULL; | |
460 | videocodec_proc_entry->data = NULL; | |
461 | videocodec_proc_entry->owner = THIS_MODULE; | |
462 | } else { | |
463 | dprintk(1, KERN_ERR "videocodec: can't init procfs.\n"); | |
464 | } | |
465 | #endif | |
466 | return 0; | |
467 | } | |
468 | ||
469 | static void __exit | |
470 | videocodec_exit (void) | |
471 | { | |
472 | #ifdef CONFIG_PROC_FS | |
473 | remove_proc_entry("videocodecs", NULL); | |
474 | if (videocodec_buf) | |
475 | kfree(videocodec_buf); | |
476 | #endif | |
477 | } | |
478 | ||
479 | EXPORT_SYMBOL(videocodec_attach); | |
480 | EXPORT_SYMBOL(videocodec_detach); | |
481 | EXPORT_SYMBOL(videocodec_register); | |
482 | EXPORT_SYMBOL(videocodec_unregister); | |
483 | ||
484 | module_init(videocodec_init); | |
485 | module_exit(videocodec_exit); | |
486 | ||
487 | MODULE_AUTHOR("Wolfgang Scherr <scherr@net4you.at>"); | |
488 | MODULE_DESCRIPTION("Intermediate API module for video codecs " | |
489 | VIDEOCODEC_VERSION); | |
490 | MODULE_LICENSE("GPL"); |