Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/x86
[linux-2.6] / drivers / media / video / videocodec.c
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 = kzalloc(sizeof(struct attached_list), GFP_KERNEL);
128                                 if (!ptr) {
129                                         dprintk(1,
130                                                 KERN_ERR
131                                                 "videocodec_attach: no memory\n");
132                                         goto out_kfree;
133                                 }
134                                 ptr->codec = codec;
135
136                                 a = h->list;
137                                 if (!a) {
138                                         h->list = ptr;
139                                         dprintk(4,
140                                                 "videocodec: first element\n");
141                                 } else {
142                                         while (a->next)
143                                                 a = a->next;    // find end
144                                         a->next = ptr;
145                                         dprintk(4,
146                                                 "videocodec: in after '%s'\n",
147                                                 h->codec->name);
148                                 }
149
150                                 h->attached += 1;
151                                 return codec;
152                         } else {
153                                 kfree(codec);
154                         }
155                 }
156                 h = h->next;
157         }
158
159         dprintk(1, KERN_ERR "videocodec_attach: no codec found!\n");
160         return NULL;
161
162  out_module_put:
163         module_put(h->codec->owner);
164  out_kfree:
165         kfree(codec);
166         return NULL;
167 }
168
169 int
170 videocodec_detach (struct videocodec *codec)
171 {
172         struct codec_list *h = codeclist_top;
173         struct attached_list *a, *prev;
174         int res;
175
176         if (!codec) {
177                 dprintk(1, KERN_ERR "videocodec_detach: no data\n");
178                 return -EINVAL;
179         }
180
181         dprintk(2,
182                 "videocodec_detach: '%s', type: %x, flags %lx, magic %lx\n",
183                 codec->name, codec->type, codec->flags, codec->magic);
184
185         if (!h) {
186                 dprintk(1,
187                         KERN_ERR "videocodec_detach: no device left...\n");
188                 return -ENXIO;
189         }
190
191         while (h) {
192                 a = h->list;
193                 prev = NULL;
194                 while (a) {
195                         if (codec == a->codec) {
196                                 res = a->codec->unset(a->codec);
197                                 if (res >= 0) {
198                                         dprintk(3,
199                                                 "videocodec_detach: '%s'\n",
200                                                 a->codec->name);
201                                         a->codec->master_data = NULL;
202                                 } else {
203                                         dprintk(1,
204                                                 KERN_ERR
205                                                 "videocodec_detach: '%s'\n",
206                                                 a->codec->name);
207                                         a->codec->master_data = NULL;
208                                 }
209                                 if (prev == NULL) {
210                                         h->list = a->next;
211                                         dprintk(4,
212                                                 "videocodec: delete first\n");
213                                 } else {
214                                         prev->next = a->next;
215                                         dprintk(4,
216                                                 "videocodec: delete middle\n");
217                                 }
218                                 module_put(a->codec->owner);
219                                 kfree(a->codec);
220                                 kfree(a);
221                                 h->attached -= 1;
222                                 return 0;
223                         }
224                         prev = a;
225                         a = a->next;
226                 }
227                 h = h->next;
228         }
229
230         dprintk(1, KERN_ERR "videocodec_detach: given codec not found!\n");
231         return -EINVAL;
232 }
233
234 int
235 videocodec_register (const struct videocodec *codec)
236 {
237         struct codec_list *ptr, *h = codeclist_top;
238
239         if (!codec) {
240                 dprintk(1, KERN_ERR "videocodec_register: no data!\n");
241                 return -EINVAL;
242         }
243
244         dprintk(2,
245                 "videocodec: register '%s', type: %x, flags %lx, magic %lx\n",
246                 codec->name, codec->type, codec->flags, codec->magic);
247
248         ptr = kzalloc(sizeof(struct codec_list), GFP_KERNEL);
249         if (!ptr) {
250                 dprintk(1, KERN_ERR "videocodec_register: no memory\n");
251                 return -ENOMEM;
252         }
253         ptr->codec = codec;
254
255         if (!h) {
256                 codeclist_top = ptr;
257                 dprintk(4, "videocodec: hooked in as first element\n");
258         } else {
259                 while (h->next)
260                         h = h->next;    // find the end
261                 h->next = ptr;
262                 dprintk(4, "videocodec: hooked in after '%s'\n",
263                         h->codec->name);
264         }
265
266         return 0;
267 }
268
269 int
270 videocodec_unregister (const struct videocodec *codec)
271 {
272         struct codec_list *prev = NULL, *h = codeclist_top;
273
274         if (!codec) {
275                 dprintk(1, KERN_ERR "videocodec_unregister: no data!\n");
276                 return -EINVAL;
277         }
278
279         dprintk(2,
280                 "videocodec: unregister '%s', type: %x, flags %lx, magic %lx\n",
281                 codec->name, codec->type, codec->flags, codec->magic);
282
283         if (!h) {
284                 dprintk(1,
285                         KERN_ERR
286                         "videocodec_unregister: no device left...\n");
287                 return -ENXIO;
288         }
289
290         while (h) {
291                 if (codec == h->codec) {
292                         if (h->attached) {
293                                 dprintk(1,
294                                         KERN_ERR
295                                         "videocodec: '%s' is used\n",
296                                         h->codec->name);
297                                 return -EBUSY;
298                         }
299                         dprintk(3, "videocodec: unregister '%s' is ok.\n",
300                                 h->codec->name);
301                         if (prev == NULL) {
302                                 codeclist_top = h->next;
303                                 dprintk(4,
304                                         "videocodec: delete first element\n");
305                         } else {
306                                 prev->next = h->next;
307                                 dprintk(4,
308                                         "videocodec: delete middle element\n");
309                         }
310                         kfree(h);
311                         return 0;
312                 }
313                 prev = h;
314                 h = h->next;
315         }
316
317         dprintk(1,
318                 KERN_ERR
319                 "videocodec_unregister: given codec not found!\n");
320         return -EINVAL;
321 }
322
323 #ifdef CONFIG_PROC_FS
324 /* ============ */
325 /* procfs stuff */
326 /* ============ */
327
328 static char *videocodec_buf = NULL;
329 static int videocodec_bufsize = 0;
330
331 static int
332 videocodec_build_table (void)
333 {
334         struct codec_list *h = codeclist_top;
335         struct attached_list *a;
336         int i = 0, size;
337
338         // sum up amount of slaves plus their attached masters
339         while (h) {
340                 i += h->attached + 1;
341                 h = h->next;
342         }
343 #define LINESIZE 100
344         size = LINESIZE * (i + 1);
345
346         dprintk(3, "videocodec_build table: %d entries, %d bytes\n", i,
347                 size);
348
349         kfree(videocodec_buf);
350         videocodec_buf = (char *) kmalloc(size, GFP_KERNEL);
351
352         i = 0;
353         i += scnprintf(videocodec_buf + i, size - 1,
354                       "<S>lave or attached <M>aster name  type flags    magic    ");
355         i += scnprintf(videocodec_buf + i, size -i - 1, "(connected as)\n");
356
357         h = codeclist_top;
358         while (h) {
359                 if (i > (size - LINESIZE))
360                         break;  // security check
361                 i += scnprintf(videocodec_buf + i, size -i -1,
362                               "S %32s %04x %08lx %08lx (TEMPLATE)\n",
363                               h->codec->name, h->codec->type,
364                               h->codec->flags, h->codec->magic);
365                 a = h->list;
366                 while (a) {
367                         if (i > (size - LINESIZE))
368                                 break;  // security check
369                         i += scnprintf(videocodec_buf + i, size -i -1,
370                                       "M %32s %04x %08lx %08lx (%s)\n",
371                                       a->codec->master_data->name,
372                                       a->codec->master_data->type,
373                                       a->codec->master_data->flags,
374                                       a->codec->master_data->magic,
375                                       a->codec->name);
376                         a = a->next;
377                 }
378                 h = h->next;
379         }
380
381         return i;
382 }
383
384 //The definition:
385 //typedef int (read_proc_t)(char *page, char **start, off_t off,
386 //                          int count, int *eof, void *data);
387
388 static int
389 videocodec_info (char  *buffer,
390                  char **buffer_location,
391                  off_t  offset,
392                  int    buffer_length,
393                  int   *eof,
394                  void  *data)
395 {
396         int size;
397
398         dprintk(3, "videocodec_info: offset: %ld, len %d / size %d\n",
399                 offset, buffer_length, videocodec_bufsize);
400
401         if (offset == 0) {
402                 videocodec_bufsize = videocodec_build_table();
403         }
404         if ((offset < 0) || (offset >= videocodec_bufsize)) {
405                 dprintk(4,
406                         "videocodec_info: call delivers no result, return 0\n");
407                 *eof = 1;
408                 return 0;
409         }
410
411         if (buffer_length < (videocodec_bufsize - offset)) {
412                 dprintk(4, "videocodec_info: %ld needed, %d got\n",
413                         videocodec_bufsize - offset, buffer_length);
414                 size = buffer_length;
415         } else {
416                 dprintk(4, "videocodec_info: last reading of %ld bytes\n",
417                         videocodec_bufsize - offset);
418                 size = videocodec_bufsize - offset;
419                 *eof = 1;
420         }
421
422         memcpy(buffer, videocodec_buf + offset, size);
423         /* doesn't work...                           */
424         /* copy_to_user(buffer, videocodec_buf+offset, size); */
425         /* *buffer_location = videocodec_buf+offset; */
426
427         return size;
428 }
429 #endif
430
431 /* ===================== */
432 /* hook in driver module */
433 /* ===================== */
434 static int __init
435 videocodec_init (void)
436 {
437 #ifdef CONFIG_PROC_FS
438         static struct proc_dir_entry *videocodec_proc_entry;
439 #endif
440
441         printk(KERN_INFO "Linux video codec intermediate layer: %s\n",
442                VIDEOCODEC_VERSION);
443
444 #ifdef CONFIG_PROC_FS
445         videocodec_buf = NULL;
446         videocodec_bufsize = 0;
447
448         videocodec_proc_entry = create_proc_entry("videocodecs", 0, NULL);
449         if (videocodec_proc_entry) {
450                 videocodec_proc_entry->read_proc = videocodec_info;
451                 videocodec_proc_entry->write_proc = NULL;
452                 videocodec_proc_entry->data = NULL;
453                 videocodec_proc_entry->owner = THIS_MODULE;
454         } else {
455                 dprintk(1, KERN_ERR "videocodec: can't init procfs.\n");
456         }
457 #endif
458         return 0;
459 }
460
461 static void __exit
462 videocodec_exit (void)
463 {
464 #ifdef CONFIG_PROC_FS
465         remove_proc_entry("videocodecs", NULL);
466         kfree(videocodec_buf);
467 #endif
468 }
469
470 EXPORT_SYMBOL(videocodec_attach);
471 EXPORT_SYMBOL(videocodec_detach);
472 EXPORT_SYMBOL(videocodec_register);
473 EXPORT_SYMBOL(videocodec_unregister);
474
475 module_init(videocodec_init);
476 module_exit(videocodec_exit);
477
478 MODULE_AUTHOR("Wolfgang Scherr <scherr@net4you.at>");
479 MODULE_DESCRIPTION("Intermediate API module for video codecs "
480                    VIDEOCODEC_VERSION);
481 MODULE_LICENSE("GPL");