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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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)
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
40#ifdef CONFIG_PROC_FS
41#include <linux/proc_fs.h>
42#include <asm/uaccess.h>
43#endif
44
45#include "videocodec.h"
46
47static int debug = 0;
48module_param(debug, int, 0);
49MODULE_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
57struct attached_list {
58 struct videocodec *codec;
59 struct attached_list *next;
60};
61
62struct codec_list {
63 const struct videocodec *codec;
64 int attached;
65 struct attached_list *list;
66 struct codec_list *next;
67};
68
69static struct codec_list *codeclist_top = NULL;
70
71/* ================================================= */
72/* function prototypes of the master/slave interface */
73/* ================================================= */
74
75struct videocodec *
76videocodec_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,
89 "videocodec_attach: '%s', type: %x, flags %lx, magic %lx\n",
90 master->name, master->type, master->flags, master->magic);
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);
Panagiotis Issaris74081872006-01-11 19:40:56 -0200126 ptr = kzalloc(sizeof(struct attached_list), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 if (!ptr) {
128 dprintk(1,
129 KERN_ERR
130 "videocodec_attach: no memory\n");
131 goto out_kfree;
132 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 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
168int
169videocodec_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
233int
234videocodec_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
Panagiotis Issaris74081872006-01-11 19:40:56 -0200247 ptr = kzalloc(sizeof(struct codec_list), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 if (!ptr) {
249 dprintk(1, KERN_ERR "videocodec_register: no memory\n");
250 return -ENOMEM;
251 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 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
268int
269videocodec_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
327static char *videocodec_buf = NULL;
328static int videocodec_bufsize = 0;
329
330static int
331videocodec_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
Jesper Juhl2ea75332005-11-07 01:01:31 -0800348 kfree(videocodec_buf);
Robert P. J. Day5cbded52006-12-13 00:35:56 -0800349 videocodec_buf = kmalloc(size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350
Amit Choudhary20ec8112007-03-30 17:34:14 -0300351 if (!videocodec_buf)
352 return 0;
353
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 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
390static int
391videocodec_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/* ===================== */
436static int __init
437videocodec_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
463static void __exit
464videocodec_exit (void)
465{
466#ifdef CONFIG_PROC_FS
467 remove_proc_entry("videocodecs", NULL);
Jesper Juhl2ea75332005-11-07 01:01:31 -0800468 kfree(videocodec_buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469#endif
470}
471
472EXPORT_SYMBOL(videocodec_attach);
473EXPORT_SYMBOL(videocodec_detach);
474EXPORT_SYMBOL(videocodec_register);
475EXPORT_SYMBOL(videocodec_unregister);
476
477module_init(videocodec_init);
478module_exit(videocodec_exit);
479
480MODULE_AUTHOR("Wolfgang Scherr <scherr@net4you.at>");
481MODULE_DESCRIPTION("Intermediate API module for video codecs "
482 VIDEOCODEC_VERSION);
483MODULE_LICENSE("GPL");