drivers/media/pci/zoran/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  * ------------------------------------------------------------------------
  24  */
  25
  26 #define VIDEOCODEC_VERSION "v0.2"
  27
  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>
  33
  34 // kernel config is here (procfs flag)
  35
  36 #ifdef CONFIG_PROC_FS
  37 #include <linux/proc_fs.h>
  38 #include <linux/seq_file.h>
  39 #include <linux/uaccess.h>
  40 #endif
  41
  42 #include "videocodec.h"
  43
  44 static int debug;
  45 module_param(debug, int, 0);
  46 MODULE_PARM_DESC(debug, "Debug level (0-4)");
  47
  48 #define dprintk(num, format, args...) \
  49         do { \
  50                 if (debug >= num) \
  51                         printk(format, ##args); \
  52         } while (0)
  53
  54 struct attached_list {
  55         struct videocodec *codec;
  56         struct attached_list *next;
  57 };
  58
  59 struct codec_list {
  60         const struct videocodec *codec;
  61         int attached;
  62         struct attached_list *list;
  63         struct codec_list *next;
  64 };
  65
  66 static struct codec_list *codeclist_top = NULL;
  67
  68 /* ================================================= */
  69 /* function prototypes of the master/slave interface */
  70 /* ================================================= */
  71
  72 struct videocodec *
  73 videocodec_attach (struct videocodec_master *master)
  74 {
  75         struct codec_list *h = codeclist_top;
  76         struct attached_list *a, *ptr;
  77         struct videocodec *codec;
  78         int res;
  79
  80         if (!master) {
  81                 dprintk(1, KERN_ERR "videocodec_attach: no data\n");
  82                 return NULL;
  83         }
  84
  85         dprintk(2,
  86                 "videocodec_attach: '%s', flags %lx, magic %lx\n",
  87                 master->name, master->flags, master->magic);
  88
  89         if (!h) {
  90                 dprintk(1,
  91                         KERN_ERR
  92                         "videocodec_attach: no device available\n");
  93                 return NULL;
  94         }
  95
  96         while (h) {
  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",
 101                                 h->codec->name);
 102
 103                         if (!try_module_get(h->codec->owner))
 104                                 return NULL;
 105
 106                         codec = kmemdup(h->codec, sizeof(struct videocodec),
 107                                         GFP_KERNEL);
 108                         if (!codec) {
 109                                 dprintk(1,
 110                                         KERN_ERR
 111                                         "videocodec_attach: no mem\n");
 112                                 goto out_module_put;
 113                         }
 114
 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);
 120                         if (res == 0) {
 121                                 dprintk(3, "videocodec_attach '%s'\n",
 122                                         codec->name);
 123                                 ptr = kzalloc(sizeof(struct attached_list), GFP_KERNEL);
 124                                 if (!ptr) {
 125                                         dprintk(1,
 126                                                 KERN_ERR
 127                                                 "videocodec_attach: no memory\n");
 128                                         goto out_kfree;
 129                                 }
 130                                 ptr->codec = codec;
 131
 132                                 a = h->list;
 133                                 if (!a) {
 134                                         h->list = ptr;
 135                                         dprintk(4,
 136                                                 "videocodec: first element\n");
 137                                 } else {
 138                                         while (a->next)
 139                                                 a = a->next;    // find end
 140                                         a->next = ptr;
 141                                         dprintk(4,
 142                                                 "videocodec: in after '%s'\n",
 143                                                 h->codec->name);
 144                                 }
 145
 146                                 h->attached += 1;
 147                                 return codec;
 148                         } else {
 149                                 kfree(codec);
 150                         }
 151                 }
 152                 h = h->next;
 153         }
 154
 155         dprintk(1, KERN_ERR "videocodec_attach: no codec found!\n");
 156         return NULL;
 157
 158  out_module_put:
 159         module_put(h->codec->owner);
 160  out_kfree:
 161         kfree(codec);
 162         return NULL;
 163 }
 164
 165 int
 166 videocodec_detach (struct videocodec *codec)
 167 {
 168         struct codec_list *h = codeclist_top;
 169         struct attached_list *a, *prev;
 170         int res;
 171
 172         if (!codec) {
 173                 dprintk(1, KERN_ERR "videocodec_detach: no data\n");
 174                 return -EINVAL;
 175         }
 176
 177         dprintk(2,
 178                 "videocodec_detach: '%s', type: %x, flags %lx, magic %lx\n",
 179                 codec->name, codec->type, codec->flags, codec->magic);
 180
 181         if (!h) {
 182                 dprintk(1,
 183                         KERN_ERR "videocodec_detach: no device left...\n");
 184                 return -ENXIO;
 185         }
 186
 187         while (h) {
 188                 a = h->list;
 189                 prev = NULL;
 190                 while (a) {
 191                         if (codec == a->codec) {
 192                                 res = a->codec->unset(a->codec);
 193                                 if (res >= 0) {
 194                                         dprintk(3,
 195                                                 "videocodec_detach: '%s'\n",
 196                                                 a->codec->name);
 197                                         a->codec->master_data = NULL;
 198                                 } else {
 199                                         dprintk(1,
 200                                                 KERN_ERR
 201                                                 "videocodec_detach: '%s'\n",
 202                                                 a->codec->name);
 203                                         a->codec->master_data = NULL;
 204                                 }
 205                                 if (prev == NULL) {
 206                                         h->list = a->next;
 207                                         dprintk(4,
 208                                                 "videocodec: delete first\n");
 209                                 } else {
 210                                         prev->next = a->next;
 211                                         dprintk(4,
 212                                                 "videocodec: delete middle\n");
 213                                 }
 214                                 module_put(a->codec->owner);
 215                                 kfree(a->codec);
 216                                 kfree(a);
 217                                 h->attached -= 1;
 218                                 return 0;
 219                         }
 220                         prev = a;
 221                         a = a->next;
 222                 }
 223                 h = h->next;
 224         }
 225
 226         dprintk(1, KERN_ERR "videocodec_detach: given codec not found!\n");
 227         return -EINVAL;
 228 }
 229
 230 int
 231 videocodec_register (const struct videocodec *codec)
 232 {
 233         struct codec_list *ptr, *h = codeclist_top;
 234
 235         if (!codec) {
 236                 dprintk(1, KERN_ERR "videocodec_register: no data!\n");
 237                 return -EINVAL;
 238         }
 239
 240         dprintk(2,
 241                 "videocodec: register '%s', type: %x, flags %lx, magic %lx\n",
 242                 codec->name, codec->type, codec->flags, codec->magic);
 243
 244         ptr = kzalloc(sizeof(struct codec_list), GFP_KERNEL);
 245         if (!ptr) {
 246                 dprintk(1, KERN_ERR "videocodec_register: no memory\n");
 247                 return -ENOMEM;
 248         }
 249         ptr->codec = codec;
 250
 251         if (!h) {
 252                 codeclist_top = ptr;
 253                 dprintk(4, "videocodec: hooked in as first element\n");
 254         } else {
 255                 while (h->next)
 256                         h = h->next;    // find the end
 257                 h->next = ptr;
 258                 dprintk(4, "videocodec: hooked in after '%s'\n",
 259                         h->codec->name);
 260         }
 261
 262         return 0;
 263 }
 264
 265 int
 266 videocodec_unregister (const struct videocodec *codec)
 267 {
 268         struct codec_list *prev = NULL, *h = codeclist_top;
 269
 270         if (!codec) {
 271                 dprintk(1, KERN_ERR "videocodec_unregister: no data!\n");
 272                 return -EINVAL;
 273         }
 274
 275         dprintk(2,
 276                 "videocodec: unregister '%s', type: %x, flags %lx, magic %lx\n",
 277                 codec->name, codec->type, codec->flags, codec->magic);
 278
 279         if (!h) {
 280                 dprintk(1,
 281                         KERN_ERR
 282                         "videocodec_unregister: no device left...\n");
 283                 return -ENXIO;
 284         }
 285
 286         while (h) {
 287                 if (codec == h->codec) {
 288                         if (h->attached) {
 289                                 dprintk(1,
 290                                         KERN_ERR
 291                                         "videocodec: '%s' is used\n",
 292                                         h->codec->name);
 293                                 return -EBUSY;
 294                         }
 295                         dprintk(3, "videocodec: unregister '%s' is ok.\n",
 296                                 h->codec->name);
 297                         if (prev == NULL) {
 298                                 codeclist_top = h->next;
 299                                 dprintk(4,
 300                                         "videocodec: delete first element\n");
 301                         } else {
 302                                 prev->next = h->next;
 303                                 dprintk(4,
 304                                         "videocodec: delete middle element\n");
 305                         }
 306                         kfree(h);
 307                         return 0;
 308                 }
 309                 prev = h;
 310                 h = h->next;
 311         }
 312
 313         dprintk(1,
 314                 KERN_ERR
 315                 "videocodec_unregister: given codec not found!\n");
 316         return -EINVAL;
 317 }
 318
 319 #ifdef CONFIG_PROC_FS
 320 static int proc_videocodecs_show(struct seq_file *m, void *v)
 321 {
 322         struct codec_list *h = codeclist_top;
 323         struct attached_list *a;
 324
 325         seq_printf(m, "<S>lave or attached <M>aster name  type flags    magic    ");
 326         seq_printf(m, "(connected as)\n");
 327
 328         h = codeclist_top;
 329         while (h) {
 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);
 333                 a = h->list;
 334                 while (a) {
 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,
 340                                       a->codec->name);
 341                         a = a->next;
 342                 }
 343                 h = h->next;
 344         }
 345
 346         return 0;
 347 }
 348
 349 static int proc_videocodecs_open(struct inode *inode, struct file *file)
 350 {
 351         return single_open(file, proc_videocodecs_show, NULL);
 352 }
 353
 354 static const struct file_operations videocodecs_proc_fops = {
 355         .owner          = THIS_MODULE,
 356         .open           = proc_videocodecs_open,
 357         .read           = seq_read,
 358         .llseek         = seq_lseek,
 359         .release        = single_release,
 360 };
 361 #endif
 362
 363 /* ===================== */
 364 /* hook in driver module */
 365 /* ===================== */
 366 static int __init
 367 videocodec_init (void)
 368 {
 369 #ifdef CONFIG_PROC_FS
 370         static struct proc_dir_entry *videocodec_proc_entry;
 371 #endif
 372
 373         printk(KERN_INFO "Linux video codec intermediate layer: %s\n",
 374                VIDEOCODEC_VERSION);
 375
 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");
 380         }
 381 #endif
 382         return 0;
 383 }
 384
 385 static void __exit
 386 videocodec_exit (void)
 387 {
 388 #ifdef CONFIG_PROC_FS
 389         remove_proc_entry("videocodecs", NULL);
 390 #endif
 391 }
 392
 393 EXPORT_SYMBOL(videocodec_attach);
 394 EXPORT_SYMBOL(videocodec_detach);
 395 EXPORT_SYMBOL(videocodec_register);
 396 EXPORT_SYMBOL(videocodec_unregister);
 397
 398 module_init(videocodec_init);
 399 module_exit(videocodec_exit);
 400
 401 MODULE_AUTHOR("Wolfgang Scherr <scherr@net4you.at>");
 402 MODULE_DESCRIPTION("Intermediate API module for video codecs "
 403                    VIDEOCODEC_VERSION);
 404 MODULE_LICENSE("GPL");