2 * VIDEO MOTION CODECs internal API for video devices
4 * Interface for MJPEG (and maybe later MPEG/WAVELETS) codec's
5 * bound to a master device.
7 * (c) 2002 Wolfgang Scherr <scherr@net4you.at>
9 * $Id: videocodec.c,v 1.1.2.8 2003/03/29 07:16:04 rbultje Exp $
11 * ------------------------------------------------------------------------
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.
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.
23 * ------------------------------------------------------------------------
26 #define VIDEOCODEC_VERSION "v0.2"
28 #include <linux/kernel.h>
29 #include <linux/module.h>
30 #include <linux/init.h>
31 #include <linux/types.h>
32 #include <linux/slab.h>
34 // kernel config is here (procfs flag)
37 #include <linux/proc_fs.h>
38 #include <linux/seq_file.h>
39 #include <linux/uaccess.h>
42 #include "videocodec.h"
45 module_param(debug, int, 0);
46 MODULE_PARM_DESC(debug, "Debug level (0-4)");
48 #define dprintk(num, format, args...) \
51 printk(format, ##args); \
54 struct attached_list {
55 struct videocodec *codec;
56 struct attached_list *next;
60 const struct videocodec *codec;
62 struct attached_list *list;
63 struct codec_list *next;
66 static struct codec_list *codeclist_top = NULL;
68 /* ================================================= */
69 /* function prototypes of the master/slave interface */
70 /* ================================================= */
73 videocodec_attach (struct videocodec_master *master)
75 struct codec_list *h = codeclist_top;
76 struct attached_list *a, *ptr;
77 struct videocodec *codec;
81 dprintk(1, KERN_ERR "videocodec_attach: no data\n");
86 "videocodec_attach: '%s', flags %lx, magic %lx\n",
87 master->name, master->flags, master->magic);
92 "videocodec_attach: no device available\n");
97 // attach only if the slave has at least the flags
98 // expected by the master
99 if ((master->flags & h->codec->flags) == master->flags) {
100 dprintk(4, "videocodec_attach: try '%s'\n",
103 if (!try_module_get(h->codec->owner))
106 codec = kmemdup(h->codec, sizeof(struct videocodec),
111 "videocodec_attach: no mem\n");
115 res = strlen(codec->name);
116 snprintf(codec->name + res, sizeof(codec->name) - res,
117 "[%d]", h->attached);
118 codec->master_data = master;
119 res = codec->setup(codec);
121 dprintk(3, "videocodec_attach '%s'\n",
123 ptr = kzalloc(sizeof(struct attached_list), GFP_KERNEL);
127 "videocodec_attach: no memory\n");
136 "videocodec: first element\n");
139 a = a->next; // find end
142 "videocodec: in after '%s'\n",
155 dprintk(1, KERN_ERR "videocodec_attach: no codec found!\n");
159 module_put(h->codec->owner);
166 videocodec_detach (struct videocodec *codec)
168 struct codec_list *h = codeclist_top;
169 struct attached_list *a, *prev;
173 dprintk(1, KERN_ERR "videocodec_detach: no data\n");
178 "videocodec_detach: '%s', type: %x, flags %lx, magic %lx\n",
179 codec->name, codec->type, codec->flags, codec->magic);
183 KERN_ERR "videocodec_detach: no device left...\n");
191 if (codec == a->codec) {
192 res = a->codec->unset(a->codec);
195 "videocodec_detach: '%s'\n",
197 a->codec->master_data = NULL;
201 "videocodec_detach: '%s'\n",
203 a->codec->master_data = NULL;
208 "videocodec: delete first\n");
210 prev->next = a->next;
212 "videocodec: delete middle\n");
214 module_put(a->codec->owner);
226 dprintk(1, KERN_ERR "videocodec_detach: given codec not found!\n");
231 videocodec_register (const struct videocodec *codec)
233 struct codec_list *ptr, *h = codeclist_top;
236 dprintk(1, KERN_ERR "videocodec_register: no data!\n");
241 "videocodec: register '%s', type: %x, flags %lx, magic %lx\n",
242 codec->name, codec->type, codec->flags, codec->magic);
244 ptr = kzalloc(sizeof(struct codec_list), GFP_KERNEL);
246 dprintk(1, KERN_ERR "videocodec_register: no memory\n");
253 dprintk(4, "videocodec: hooked in as first element\n");
256 h = h->next; // find the end
258 dprintk(4, "videocodec: hooked in after '%s'\n",
266 videocodec_unregister (const struct videocodec *codec)
268 struct codec_list *prev = NULL, *h = codeclist_top;
271 dprintk(1, KERN_ERR "videocodec_unregister: no data!\n");
276 "videocodec: unregister '%s', type: %x, flags %lx, magic %lx\n",
277 codec->name, codec->type, codec->flags, codec->magic);
282 "videocodec_unregister: no device left...\n");
287 if (codec == h->codec) {
291 "videocodec: '%s' is used\n",
295 dprintk(3, "videocodec: unregister '%s' is ok.\n",
298 codeclist_top = h->next;
300 "videocodec: delete first element\n");
302 prev->next = h->next;
304 "videocodec: delete middle element\n");
315 "videocodec_unregister: given codec not found!\n");
319 #ifdef CONFIG_PROC_FS
320 static int proc_videocodecs_show(struct seq_file *m, void *v)
322 struct codec_list *h = codeclist_top;
323 struct attached_list *a;
325 seq_printf(m, "<S>lave or attached <M>aster name type flags magic ");
326 seq_printf(m, "(connected as)\n");
330 seq_printf(m, "S %32s %04x %08lx %08lx (TEMPLATE)\n",
331 h->codec->name, h->codec->type,
332 h->codec->flags, h->codec->magic);
335 seq_printf(m, "M %32s %04x %08lx %08lx (%s)\n",
336 a->codec->master_data->name,
337 a->codec->master_data->type,
338 a->codec->master_data->flags,
339 a->codec->master_data->magic,
349 static int proc_videocodecs_open(struct inode *inode, struct file *file)
351 return single_open(file, proc_videocodecs_show, NULL);
354 static const struct file_operations videocodecs_proc_fops = {
355 .owner = THIS_MODULE,
356 .open = proc_videocodecs_open,
359 .release = single_release,
363 /* ===================== */
364 /* hook in driver module */
365 /* ===================== */
367 videocodec_init (void)
369 #ifdef CONFIG_PROC_FS
370 static struct proc_dir_entry *videocodec_proc_entry;
373 printk(KERN_INFO "Linux video codec intermediate layer: %s\n",
376 #ifdef CONFIG_PROC_FS
377 videocodec_proc_entry = proc_create("videocodecs", 0, NULL, &videocodecs_proc_fops);
378 if (!videocodec_proc_entry) {
379 dprintk(1, KERN_ERR "videocodec: can't init procfs.\n");
386 videocodec_exit (void)
388 #ifdef CONFIG_PROC_FS
389 remove_proc_entry("videocodecs", NULL);
393 EXPORT_SYMBOL(videocodec_attach);
394 EXPORT_SYMBOL(videocodec_detach);
395 EXPORT_SYMBOL(videocodec_register);
396 EXPORT_SYMBOL(videocodec_unregister);
398 module_init(videocodec_init);
399 module_exit(videocodec_exit);
401 MODULE_AUTHOR("Wolfgang Scherr <scherr@net4you.at>");
402 MODULE_DESCRIPTION("Intermediate API module for video codecs "
404 MODULE_LICENSE("GPL");