aboutsummaryrefslogtreecommitdiff
path: root/drivers/media/video/videocodec.c
blob: 87951ec8254f47cd8be33557237cd7bedf54d902 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
/*
 * VIDEO MOTION CODECs internal API for video devices
 *
 * Interface for MJPEG (and maybe later MPEG/WAVELETS) codec's
 * bound to a master device.
 *
 * (c) 2002 Wolfgang Scherr <scherr@net4you.at>
 *
 * $Id: videocodec.c,v 1.1.2.8 2003/03/29 07:16:04 rbultje Exp $
 *
 * ------------------------------------------------------------------------
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * ------------------------------------------------------------------------
 */

#define VIDEOCODEC_VERSION "v0.2"

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/slab.h>

// kernel config is here (procfs flag)

#ifdef CONFIG_PROC_FS
#include <linux/proc_fs.h>
#include <asm/uaccess.h>
#endif

#include "videocodec.h"

static int debug = 0;
module_param(debug, int, 0);
MODULE_PARM_DESC(debug, "Debug level (0-4)");

#define dprintk(num, format, args...) \
	do { \
		if (debug >= num) \
			printk(format, ##args); \
	} while (0)

struct attached_list {
	struct videocodec *codec;
	struct attached_list *next;
};

struct codec_list {
	const struct videocodec *codec;
	int attached;
	struct attached_list *list;
	struct codec_list *next;
};

static struct codec_list *codeclist_top = NULL;

/* ================================================= */
/* function prototypes of the master/slave interface */
/* ================================================= */

struct videocodec *
videocodec_attach (struct videocodec_master *master)
{
	struct codec_list *h = codeclist_top;
	struct attached_list *a, *ptr;
	struct videocodec *codec;
	int res;

	if (!master) {
		dprintk(1, KERN_ERR "videocodec_attach: no data\n");
		return NULL;
	}

	dprintk(2,
		"videocodec_attach: '%s', flags %lx, magic %lx\n",
		master->name, master->flags, master->magic);

	if (!h) {
		dprintk(1,
			KERN_ERR
			"videocodec_attach: no device available\n");
		return NULL;
	}

	while (h) {
		// attach only if the slave has at least the flags
		// expected by the master
		if ((master->flags & h->codec->flags) == master->flags) {
			dprintk(4, "videocodec_attach: try '%s'\n",
				h->codec->name);

			if (!try_module_get(h->codec->owner))
				return NULL;

			codec =
			    kmalloc(sizeof(struct videocodec), GFP_KERNEL);
			if (!codec) {
				dprintk(1,
					KERN_ERR
					"videocodec_attach: no mem\n");
				goto out_module_put;
			}
			memcpy(codec, h->codec, sizeof(struct videocodec));

			snprintf(codec->name, sizeof(codec->name),
				 "%s[%d]", codec->name, h->attached);
			codec->master_data = master;
			res = codec->setup(codec);
			if (res == 0) {
				dprintk(3, "videocodec_attach '%s'\n",
					codec->name);
				ptr = kzalloc(sizeof(struct attached_list), GFP_KERNEL);
				if (!ptr) {
					dprintk(1,
						KERN_ERR
						"videocodec_attach: no memory\n");
					goto out_kfree;
				}
				ptr->codec = codec;

				a = h->list;
				if (!a) {
					h->list = ptr;
					dprintk(4,
						"videocodec: first element\n");
				} else {
					while (a->next)
						a = a->next;	// find end
					a->next = ptr;
					dprintk(4,
						"videocodec: in after '%s'\n",
						h->codec->name);
				}

				h->attached += 1;
				return codec;
			} else {
				kfree(codec);
			}
		}
		h = h->next;
	}

	dprintk(1, KERN_ERR "videocodec_attach: no codec found!\n");
	return NULL;

 out_module_put:
	module_put(h->codec->owner);
 out_kfree:
	kfree(codec);
	return NULL;
}

int
videocodec_detach (struct videocodec *codec)
{
	struct codec_list *h = codeclist_top;
	struct attached_list *a, *prev;
	int res;

	if (!codec) {
		dprintk(1, KERN_ERR "videocodec_detach: no data\n");
		return -EINVAL;
	}

	dprintk(2,
		"videocodec_detach: '%s', type: %x, flags %lx, magic %lx\n",
		codec->name, codec->type, codec->flags, codec->magic);

	if (!h) {
		dprintk(1,
			KERN_ERR "videocodec_detach: no device left...\n");
		return -ENXIO;
	}

	while (h) {
		a = h->list;
		prev = NULL;
		while (a) {
			if (codec == a->codec) {
				res = a->codec->unset(a->codec);
				if (res >= 0) {
					dprintk(3,
						"videocodec_detach: '%s'\n",
						a->codec->name);
					a->codec->master_data = NULL;
				} else {
					dprintk(1,
						KERN_ERR
						"videocodec_detach: '%s'\n",
						a->codec->name);
					a->codec->master_data = NULL;
				}
				if (prev == NULL) {
					h->list = a->next;
					dprintk(4,
						"videocodec: delete first\n");
				} else {
					prev->next = a->next;
					dprintk(4,
						"videocodec: delete middle\n");
				}
				module_put(a->codec->owner);
				kfree(a->codec);
				kfree(a);
				h->attached -= 1;
				return 0;
			}
			prev = a;
			a = a->next;
		}
		h = h->next;
	}

	dprintk(1, KERN_ERR "videocodec_detach: given codec not found!\n");
	return -EINVAL;
}

int
videocodec_register (const struct videocodec *codec)
{
	struct codec_list *ptr, *h = codeclist_top;

	if (!codec) {
		dprintk(1, KERN_ERR "videocodec_register: no data!\n");
		return -EINVAL;
	}

	dprintk(2,
		"videocodec: register '%s', type: %x, flags %lx, magic %lx\n",
		codec->name, codec->type, codec->flags, codec->magic);

	ptr = kzalloc(sizeof(struct codec_list), GFP_KERNEL);
	if (!ptr) {
		dprintk(1, KERN_ERR "videocodec_register: no memory\n");
		return -ENOMEM;
	}
	ptr->codec = codec;

	if (!h) {
		codeclist_top = ptr;
		dprintk(4, "videocodec: hooked in as first element\n");
	} else {
		while (h->next)
			h = h->next;	// find the end
		h->next = ptr;
		dprintk(4, "videocodec: hooked in after '%s'\n",
			h->codec->name);
	}

	return 0;
}

int
videocodec_unregister (const struct videocodec *codec)
{
	struct codec_list *prev = NULL, *h = codeclist_top;

	if (!codec) {
		dprintk(1, KERN_ERR "videocodec_unregister: no data!\n");
		return -EINVAL;
	}

	dprintk(2,
		"videocodec: unregister '%s', type: %x, flags %lx, magic %lx\n",
		codec->name, codec->type, codec->flags, codec->magic);

	if (!h) {
		dprintk(1,
			KERN_ERR
			"videocodec_unregister: no device left...\n");
		return -ENXIO;
	}

	while (h) {
		if (codec == h->codec) {
			if (h->attached) {
				dprintk(1,
					KERN_ERR
					"videocodec: '%s' is used\n",
					h->codec->name);
				return -EBUSY;
			}
			dprintk(3, "videocodec: unregister '%s' is ok.\n",
				h->codec->name);
			if (prev == NULL) {
				codeclist_top = h->next;
				dprintk(4,
					"videocodec: delete first element\n");
			} else {
				prev->next = h->next;
				dprintk(4,
					"videocodec: delete middle element\n");
			}
			kfree(h);
			return 0;
		}
		prev = h;
		h = h->next;
	}

	dprintk(1,
		KERN_ERR
		"videocodec_unregister: given codec not found!\n");
	return -EINVAL;
}

#ifdef CONFIG_PROC_FS
/* ============ */
/* procfs stuff */
/* ============ */

static char *videocodec_buf = NULL;
static int videocodec_bufsize = 0;

static int
videocodec_build_table (void)
{
	struct codec_list *h = codeclist_top;
	struct attached_list *a;
	int i = 0, size;

	// sum up amount of slaves plus their attached masters
	while (h) {
		i += h->attached + 1;
		h = h->next;
	}
#define LINESIZE 100
	size = LINESIZE * (i + 1);

	dprintk(3, "videocodec_build table: %d entries, %d bytes\n", i,
		size);

	kfree(videocodec_buf);
	videocodec_buf = kmalloc(size, GFP_KERNEL);

	if (!videocodec_buf)
		return 0;

	i = 0;
	i += scnprintf(videocodec_buf + i, size - 1,
		      "<S>lave or attached <M>aster name  type flags    magic    ");
	i += scnprintf(videocodec_buf + i, size -i - 1, "(connected as)\n");

	h = codeclist_top;
	while (h) {
		if (i > (size - LINESIZE))
			break;	// security check
		i += scnprintf(videocodec_buf + i, size -i -1,
			      "S %32s %04x %08lx %08lx (TEMPLATE)\n",
			      h->codec->name, h->codec->type,
			      h->codec->flags, h->codec->magic);
		a = h->list;
		while (a) {
			if (i > (size - LINESIZE))
				break;	// security check
			i += scnprintf(videocodec_buf + i, size -i -1,
				      "M %32s %04x %08lx %08lx (%s)\n",
				      a->codec->master_data->name,
				      a->codec->master_data->type,
				      a->codec->master_data->flags,
				      a->codec->master_data->magic,
				      a->codec->name);
			a = a->next;
		}
		h = h->next;
	}

	return i;
}

//The definition:
//typedef int (read_proc_t)(char *page, char **start, off_t off,
//                          int count, int *eof, void *data);

static int
videocodec_info (char  *buffer,
		 char **buffer_location,
		 off_t  offset,
		 int    buffer_length,
		 int   *eof,
		 void  *data)
{
	int size;

	dprintk(3, "videocodec_info: offset: %ld, len %d / size %d\n",
		offset, buffer_length, videocodec_bufsize);

	if (offset == 0) {
		videocodec_bufsize = videocodec_build_table();
	}
	if ((offset < 0) || (offset >= videocodec_bufsize)) {
		dprintk(4,
			"videocodec_info: call delivers no result, return 0\n");
		*eof = 1;
		return 0;
	}

	if (buffer_length < (videocodec_bufsize - offset)) {
		dprintk(4, "videocodec_info: %ld needed, %d got\n",
			videocodec_bufsize - offset, buffer_length);
		size = buffer_length;
	} else {
		dprintk(4, "videocodec_info: last reading of %ld bytes\n",
			videocodec_bufsize - offset);
		size = videocodec_bufsize - offset;
		*eof = 1;
	}

	memcpy(buffer, videocodec_buf + offset, size);
	/* doesn't work...                           */
	/* copy_to_user(buffer, videocodec_buf+offset, size); */
	/* *buffer_location = videocodec_buf+offset; */

	return size;
}
#endif

/* ===================== */
/* hook in driver module */
/* ===================== */
static int __init
videocodec_init (void)
{
#ifdef CONFIG_PROC_FS
	static struct proc_dir_entry *videocodec_proc_entry;
#endif

	printk(KERN_INFO "Linux video codec intermediate layer: %s\n",
	       VIDEOCODEC_VERSION);

#ifdef CONFIG_PROC_FS
	videocodec_buf = NULL;
	videocodec_bufsize = 0;

	videocodec_proc_entry = create_proc_entry("videocodecs", 0, NULL);
	if (videocodec_proc_entry) {
		videocodec_proc_entry->read_proc = videocodec_info;
		videocodec_proc_entry->write_proc = NULL;
		videocodec_proc_entry->data = NULL;
		videocodec_proc_entry->owner = THIS_MODULE;
	} else {
		dprintk(1, KERN_ERR "videocodec: can't init procfs.\n");
	}
#endif
	return 0;
}

static void __exit
videocodec_exit (void)
{
#ifdef CONFIG_PROC_FS
	remove_proc_entry("videocodecs", NULL);
	kfree(videocodec_buf);
#endif
}

EXPORT_SYMBOL(videocodec_attach);
EXPORT_SYMBOL(videocodec_detach);
EXPORT_SYMBOL(videocodec_register);
EXPORT_SYMBOL(videocodec_unregister);

module_init(videocodec_init);
module_exit(videocodec_exit);

MODULE_AUTHOR("Wolfgang Scherr <scherr@net4you.at>");
MODULE_DESCRIPTION("Intermediate API module for video codecs "
		   VIDEOCODEC_VERSION);
MODULE_LICENSE("GPL");