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1 /* 1
2 * VIDEO MOTION CODECs internal API for video
3 *
4 * Interface for MJPEG (and maybe later MPEG/W
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 07:1
10 *
11 * -------------------------------------------
12 *
13 * This program is free software; you can redi
14 * it under the terms of the GNU General Publi
15 * the Free Software Foundation; either versio
16 * (at your option) any later version.
17 *
18 * This program is distributed in the hope tha
19 * but WITHOUT ANY WARRANTY; without even the
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR
21 * GNU General Public License for more details
22 *
23 * You should have received a copy of the GNU
24 * along with this program; if not, write to t
25 * Foundation, Inc., 675 Mass Ave, Cambridge,
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
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 int
73 /* ===========================================
74
75 struct videocodec *
76 videocodec_attach (struct videocodec_master *m
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 "videocode
85 return NULL;
86 }
87
88 dprintk(2,
89 "videocodec_attach: '%s', flag
90 master->name, master->flags, m
91
92 if (!h) {
93 dprintk(1,
94 KERN_ERR
95 "videocodec_attach: no
96 return NULL;
97 }
98
99 while (h) {
100 // attach only if the slave ha
101 // expected by the master
102 if ((master->flags & h->codec-
103 dprintk(4, "videocodec
104 h->codec->name
105
106 if (!try_module_get(h-
107 return NULL;
108
109 codec =
110 kmalloc(sizeof(str
111 if (!codec) {
112 dprintk(1,
113 KERN_E
114 "video
115 goto out_modul
116 }
117 memcpy(codec, h->codec
118
119 snprintf(codec->name,
120 "%s[%d]", cod
121 codec->master_data = m
122 res = codec->setup(cod
123 if (res == 0) {
124 dprintk(3, "vi
125 codec-
126 ptr = kzalloc(
127 if (!ptr) {
128 dprint
129
130
131 goto o
132 }
133 ptr->codec = c
134
135 a = h->list;
136 if (!a) {
137 h->lis
138 dprint
139
140 } else {
141 while
142
143 a->nex
144 dprint
145
146
147 }
148
149 h->attached +=
150 return codec;
151 } else {
152 kfree(codec);
153 }
154 }
155 h = h->next;
156 }
157
158 dprintk(1, KERN_ERR "videocodec_attach
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 "videocode
177 return -EINVAL;
178 }
179
180 dprintk(2,
181 "videocodec_detach: '%s', type
182 codec->name, codec->type, code
183
184 if (!h) {
185 dprintk(1,
186 KERN_ERR "videocodec_d
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
196 if (res >= 0)
197 dprint
198
199
200 a->cod
201 } else {
202 dprint
203
204
205
206 a->cod
207 }
208 if (prev == NU
209 h->lis
210 dprint
211
212 } else {
213 prev->
214 dprint
215
216 }
217 module_put(a->
218 kfree(a->codec
219 kfree(a);
220 h->attached -=
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
230 return -EINVAL;
231 }
232
233 int
234 videocodec_register (const struct videocodec *
235 {
236 struct codec_list *ptr, *h = codeclist
237
238 if (!codec) {
239 dprintk(1, KERN_ERR "videocode
240 return -EINVAL;
241 }
242
243 dprintk(2,
244 "videocodec: register '%s', ty
245 codec->name, codec->type, code
246
247 ptr = kzalloc(sizeof(struct codec_list
248 if (!ptr) {
249 dprintk(1, KERN_ERR "videocode
250 return -ENOMEM;
251 }
252 ptr->codec = codec;
253
254 if (!h) {
255 codeclist_top = ptr;
256 dprintk(4, "videocodec: hooked
257 } else {
258 while (h->next)
259 h = h->next; // fin
260 h->next = ptr;
261 dprintk(4, "videocodec: hooked
262 h->codec->name);
263 }
264
265 return 0;
266 }
267
268 int
269 videocodec_unregister (const struct videocodec
270 {
271 struct codec_list *prev = NULL, *h = c
272
273 if (!codec) {
274 dprintk(1, KERN_ERR "videocode
275 return -EINVAL;
276 }
277
278 dprintk(2,
279 "videocodec: unregister '%s',
280 codec->name, codec->type, code
281
282 if (!h) {
283 dprintk(1,
284 KERN_ERR
285 "videocodec_unregister
286 return -ENXIO;
287 }
288
289 while (h) {
290 if (codec == h->codec) {
291 if (h->attached) {
292 dprintk(1,
293 KERN_E
294 "video
295 h->cod
296 return -EBUSY;
297 }
298 dprintk(3, "videocodec
299 h->codec->name
300 if (prev == NULL) {
301 codeclist_top
302 dprintk(4,
303 "video
304 } else {
305 prev->next = h
306 dprintk(4,
307 "video
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
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
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
346 size);
347
348 kfree(videocodec_buf);
349 videocodec_buf = kmalloc(size, GFP_KER
350
351 if (!videocodec_buf)
352 return 0;
353
354 i = 0;
355 i += scnprintf(videocodec_buf + i, siz
356 "<S>lave or attached <M>
357 i += scnprintf(videocodec_buf + i, siz
358
359 h = codeclist_top;
360 while (h) {
361 if (i > (size - LINESIZE))
362 break; // security ch
363 i += scnprintf(videocodec_buf
364 "S %32s %04x %08
365 h->codec->name,
366 h->codec->flags,
367 a = h->list;
368 while (a) {
369 if (i > (size - LINESI
370 break; // sec
371 i += scnprintf(videoco
372 "M %32s
373 a->codec
374 a->codec
375 a->codec
376 a->codec
377 a->codec
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 *
388 // int count, int *eo
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: %
401 offset, buffer_length, videoco
402
403 if (offset == 0) {
404 videocodec_bufsize = videocode
405 }
406 if ((offset < 0) || (offset >= videoco
407 dprintk(4,
408 "videocodec_info: call
409 *eof = 1;
410 return 0;
411 }
412
413 if (buffer_length < (videocodec_bufsiz
414 dprintk(4, "videocodec_info: %
415 videocodec_bufsize - o
416 size = buffer_length;
417 } else {
418 dprintk(4, "videocodec_info: l
419 videocodec_bufsize - o
420 size = videocodec_bufsize - of
421 *eof = 1;
422 }
423
424 memcpy(buffer, videocodec_buf + offset
425 /* doesn't work...
426 /* copy_to_user(buffer, videocodec_buf
427 /* *buffer_location = videocodec_buf+o
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 *videocod
441 #endif
442
443 printk(KERN_INFO "Linux video codec in
444 VIDEOCODEC_VERSION);
445
446 #ifdef CONFIG_PROC_FS
447 videocodec_buf = NULL;
448 videocodec_bufsize = 0;
449
450 videocodec_proc_entry = create_proc_en
451 if (videocodec_proc_entry) {
452 videocodec_proc_entry->read_pr
453 videocodec_proc_entry->write_p
454 videocodec_proc_entry->data =
455 videocodec_proc_entry->owner =
456 } else {
457 dprintk(1, KERN_ERR "videocode
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)
468 kfree(videocodec_buf);
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
481 MODULE_DESCRIPTION("Intermediate API module fo
482 VIDEOCODEC_VERSION);
483 MODULE_LICENSE("GPL");
484
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