drivers/media/video/videobuf-core.c

   1 /*
   2  * generic helper functions for handling video4linux capture buffers
   3  *
   4  * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org>
   5  *
   6  * Highly based on video-buf written originally by:
   7  * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
   8  * (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org>
   9  * (c) 2006 Ted Walther and John Sokol
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2
  14  */
  15
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/moduleparam.h>
  19 #include <linux/slab.h>
  20 #include <linux/interrupt.h>
  21
  22 #include <media/videobuf-core.h>
  23
  24 #define MAGIC_BUFFER 0x20070728
  25 #define MAGIC_CHECK(is,should)  if (unlikely((is) != (should))) \
  26         { printk(KERN_ERR "magic mismatch: %x (expected %x)\n",is,should); BUG(); }
  27
  28 static int debug = 0;
  29 module_param(debug, int, 0644);
  30
  31 MODULE_DESCRIPTION("helper module to manage video4linux buffers");
  32 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
  33 MODULE_LICENSE("GPL");
  34
  35 #define dprintk(level, fmt, arg...)     if (debug >= level) \
  36         printk(KERN_DEBUG "vbuf: " fmt , ## arg)
  37
  38 /* --------------------------------------------------------------------- */
  39
  40 #define CALL(q, f, arg...)                                              \
  41         ( (q->int_ops->f)? q->int_ops->f(arg) : 0)
  42
  43 void* videobuf_alloc(struct videobuf_queue* q)
  44 {
  45         struct videobuf_buffer *vb;
  46
  47         BUG_ON (q->msize<sizeof(*vb));
  48
  49         if (!q->int_ops || !q->int_ops->alloc) {
  50                 printk(KERN_ERR "No specific ops defined!\n");
  51                 BUG();
  52         }
  53
  54         vb = q->int_ops->alloc(q->msize);
  55
  56         if (NULL != vb) {
  57                 init_waitqueue_head(&vb->done);
  58                 vb->magic     = MAGIC_BUFFER;
  59         }
  60
  61         return vb;
  62 }
  63
  64 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
  65 {
  66         int retval = 0;
  67         DECLARE_WAITQUEUE(wait, current);
  68
  69         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
  70         add_wait_queue(&vb->done, &wait);
  71         while (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED) {
  72                 if (non_blocking) {
  73                         retval = -EAGAIN;
  74                         break;
  75                 }
  76                 set_current_state(intr  ? TASK_INTERRUPTIBLE
  77                                         : TASK_UNINTERRUPTIBLE);
  78                 if (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED)
  79                         schedule();
  80                 set_current_state(TASK_RUNNING);
  81                 if (intr && signal_pending(current)) {
  82                         dprintk(1,"buffer waiton: -EINTR\n");
  83                         retval = -EINTR;
  84                         break;
  85                 }
  86         }
  87         remove_wait_queue(&vb->done, &wait);
  88         return retval;
  89 }
  90
  91 int videobuf_iolock(struct videobuf_queue* q, struct videobuf_buffer *vb,
  92                     struct v4l2_framebuffer *fbuf)
  93 {
  94         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
  95         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
  96
  97         /* FIXME: This is required to avoid OOPS on some cases, since mmap_mapper()
  98            method should be called before _iolock.
  99            On some cases, the mmap_mapper() is called only after scheduling.
 100
 101            However, this way is just too dirty! Better to wait for some event.
 102          */
 103         schedule_timeout(HZ);
 104
 105         return CALL(q,iolock,q,vb,fbuf);
 106 }
 107
 108 /* --------------------------------------------------------------------- */
 109
 110
 111 void videobuf_queue_core_init(struct videobuf_queue* q,
 112                          struct videobuf_queue_ops *ops,
 113                          void *dev,
 114                          spinlock_t *irqlock,
 115                          enum v4l2_buf_type type,
 116                          enum v4l2_field field,
 117                          unsigned int msize,
 118                          void *priv,
 119                          struct videobuf_qtype_ops *int_ops)
 120 {
 121         memset(q,0,sizeof(*q));
 122         q->irqlock   = irqlock;
 123         q->dev       = dev;
 124         q->type      = type;
 125         q->field     = field;
 126         q->msize     = msize;
 127         q->ops       = ops;
 128         q->priv_data = priv;
 129         q->int_ops   = int_ops;
 130
 131         /* All buffer operations are mandatory */
 132         BUG_ON (!q->ops->buf_setup);
 133         BUG_ON (!q->ops->buf_prepare);
 134         BUG_ON (!q->ops->buf_queue);
 135         BUG_ON (!q->ops->buf_release);
 136
 137         /* Having implementations for abstract methods are mandatory */
 138         BUG_ON (!q->int_ops);
 139
 140         mutex_init(&q->lock);
 141         INIT_LIST_HEAD(&q->stream);
 142 }
 143
 144 /* Locking: Only usage in bttv unsafe find way to remove */
 145 int videobuf_queue_is_busy(struct videobuf_queue *q)
 146 {
 147         int i;
 148
 149         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 150
 151         if (q->streaming) {
 152                 dprintk(1,"busy: streaming active\n");
 153                 return 1;
 154         }
 155         if (q->reading) {
 156                 dprintk(1,"busy: pending read #1\n");
 157                 return 1;
 158         }
 159         if (q->read_buf) {
 160                 dprintk(1,"busy: pending read #2\n");
 161                 return 1;
 162         }
 163         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 164                 if (NULL == q->bufs[i])
 165                         continue;
 166                 if (q->bufs[i]->map) {
 167                         dprintk(1,"busy: buffer #%d mapped\n",i);
 168                         return 1;
 169                 }
 170                 if (q->bufs[i]->state == STATE_QUEUED) {
 171                         dprintk(1,"busy: buffer #%d queued\n",i);
 172                         return 1;
 173                 }
 174                 if (q->bufs[i]->state == STATE_ACTIVE) {
 175                         dprintk(1,"busy: buffer #%d avtive\n",i);
 176                         return 1;
 177                 }
 178         }
 179         return 0;
 180 }
 181
 182 /* Locking: Caller holds q->lock */
 183 void videobuf_queue_cancel(struct videobuf_queue *q)
 184 {
 185         unsigned long flags=0;
 186         int i;
 187
 188         /* remove queued buffers from list */
 189         if (q->irqlock)
 190                 spin_lock_irqsave(q->irqlock,flags);
 191         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 192                 if (NULL == q->bufs[i])
 193                         continue;
 194                 if (q->bufs[i]->state == STATE_QUEUED) {
 195                         list_del(&q->bufs[i]->queue);
 196                         q->bufs[i]->state = STATE_ERROR;
 197                 }
 198         }
 199         if (q->irqlock)
 200                 spin_unlock_irqrestore(q->irqlock,flags);
 201
 202         /* free all buffers + clear queue */
 203         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 204                 if (NULL == q->bufs[i])
 205                         continue;
 206                 q->ops->buf_release(q,q->bufs[i]);
 207         }
 208         INIT_LIST_HEAD(&q->stream);
 209 }
 210
 211 /* --------------------------------------------------------------------- */
 212
 213 /* Locking: Caller holds q->lock */
 214 enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
 215 {
 216         enum v4l2_field field = q->field;
 217
 218         BUG_ON(V4L2_FIELD_ANY == field);
 219
 220         if (V4L2_FIELD_ALTERNATE == field) {
 221                 if (V4L2_FIELD_TOP == q->last) {
 222                         field   = V4L2_FIELD_BOTTOM;
 223                         q->last = V4L2_FIELD_BOTTOM;
 224                 } else {
 225                         field   = V4L2_FIELD_TOP;
 226                         q->last = V4L2_FIELD_TOP;
 227                 }
 228         }
 229         return field;
 230 }
 231
 232 /* Locking: Caller holds q->lock */
 233 static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
 234                             struct videobuf_buffer *vb, enum v4l2_buf_type type)
 235 {
 236         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
 237         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 238
 239         b->index    = vb->i;
 240         b->type     = type;
 241
 242         b->memory   = vb->memory;
 243         switch (b->memory) {
 244         case V4L2_MEMORY_MMAP:
 245                 b->m.offset  = vb->boff;
 246                 b->length    = vb->bsize;
 247                 break;
 248         case V4L2_MEMORY_USERPTR:
 249                 b->m.userptr = vb->baddr;
 250                 b->length    = vb->bsize;
 251                 break;
 252         case V4L2_MEMORY_OVERLAY:
 253                 b->m.offset  = vb->boff;
 254                 break;
 255         }
 256
 257         b->flags    = 0;
 258         if (vb->map)
 259                 b->flags |= V4L2_BUF_FLAG_MAPPED;
 260
 261         switch (vb->state) {
 262         case STATE_PREPARED:
 263         case STATE_QUEUED:
 264         case STATE_ACTIVE:
 265                 b->flags |= V4L2_BUF_FLAG_QUEUED;
 266                 break;
 267         case STATE_DONE:
 268         case STATE_ERROR:
 269                 b->flags |= V4L2_BUF_FLAG_DONE;
 270                 break;
 271         case STATE_NEEDS_INIT:
 272         case STATE_IDLE:
 273                 /* nothing */
 274                 break;
 275         }
 276
 277         if (vb->input != UNSET) {
 278                 b->flags |= V4L2_BUF_FLAG_INPUT;
 279                 b->input  = vb->input;
 280         }
 281
 282         b->field     = vb->field;
 283         b->timestamp = vb->ts;
 284         b->bytesused = vb->size;
 285         b->sequence  = vb->field_count >> 1;
 286 }
 287
 288 /* Locking: Caller holds q->lock */
 289 static int __videobuf_mmap_free(struct videobuf_queue *q)
 290 {
 291         int i;
 292         int rc;
 293
 294         if (!q)
 295                 return 0;
 296
 297         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 298
 299         rc  = CALL(q,mmap_free,q);
 300         if (rc<0)
 301                 return rc;
 302
 303         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 304                 if (NULL == q->bufs[i])
 305                         continue;
 306                 q->ops->buf_release(q,q->bufs[i]);
 307                 kfree(q->bufs[i]);
 308                 q->bufs[i] = NULL;
 309         }
 310
 311         return rc;
 312 }
 313
 314 int videobuf_mmap_free(struct videobuf_queue *q)
 315 {
 316         int ret;
 317         mutex_lock(&q->lock);
 318         ret = __videobuf_mmap_free(q);
 319         mutex_unlock(&q->lock);
 320         return ret;
 321 }
 322
 323 /* Locking: Caller holds q->lock */
 324 static int __videobuf_mmap_setup(struct videobuf_queue *q,
 325                         unsigned int bcount, unsigned int bsize,
 326                         enum v4l2_memory memory)
 327 {
 328         unsigned int i;
 329         int err;
 330
 331         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 332
 333         err = __videobuf_mmap_free(q);
 334         if (0 != err)
 335                 return err;
 336
 337         /* Allocate and initialize buffers */
 338         for (i = 0; i < bcount; i++) {
 339                 q->bufs[i] = videobuf_alloc(q);
 340
 341                 if (q->bufs[i] == NULL)
 342                         break;
 343
 344                 q->bufs[i]->i      = i;
 345                 q->bufs[i]->input  = UNSET;
 346                 q->bufs[i]->memory = memory;
 347                 q->bufs[i]->bsize  = bsize;
 348                 switch (memory) {
 349                 case V4L2_MEMORY_MMAP:
 350                         q->bufs[i]->boff  = bsize * i;
 351                         break;
 352                 case V4L2_MEMORY_USERPTR:
 353                 case V4L2_MEMORY_OVERLAY:
 354                         /* nothing */
 355                         break;
 356                 }
 357         }
 358
 359         if (!i)
 360                 return -ENOMEM;
 361
 362         dprintk(1,"mmap setup: %d buffers, %d bytes each\n",
 363                 i, bsize);
 364
 365         return i;
 366 }
 367
 368 int videobuf_mmap_setup(struct videobuf_queue *q,
 369                         unsigned int bcount, unsigned int bsize,
 370                         enum v4l2_memory memory)
 371 {
 372         int ret;
 373         mutex_lock(&q->lock);
 374         ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
 375         mutex_unlock(&q->lock);
 376         return ret;
 377 }
 378
 379 int videobuf_reqbufs(struct videobuf_queue *q,
 380                  struct v4l2_requestbuffers *req)
 381 {
 382         unsigned int size,count;
 383         int retval;
 384
 385         if (req->count < 1) {
 386                 dprintk(1,"reqbufs: count invalid (%d)\n",req->count);
 387                 return -EINVAL;
 388         }
 389
 390         if (req->memory != V4L2_MEMORY_MMAP     &&
 391             req->memory != V4L2_MEMORY_USERPTR  &&
 392             req->memory != V4L2_MEMORY_OVERLAY) {
 393                 dprintk(1,"reqbufs: memory type invalid\n");
 394                 return -EINVAL;
 395         }
 396
 397         mutex_lock(&q->lock);
 398         if (req->type != q->type) {
 399                 dprintk(1,"reqbufs: queue type invalid\n");
 400                 retval = -EINVAL;
 401                 goto done;
 402         }
 403
 404         if (q->streaming) {
 405                 dprintk(1,"reqbufs: streaming already exists\n");
 406                 retval = -EBUSY;
 407                 goto done;
 408         }
 409         if (!list_empty(&q->stream)) {
 410                 dprintk(1,"reqbufs: stream running\n");
 411                 retval = -EBUSY;
 412                 goto done;
 413         }
 414
 415         count = req->count;
 416         if (count > VIDEO_MAX_FRAME)
 417                 count = VIDEO_MAX_FRAME;
 418         size = 0;
 419         q->ops->buf_setup(q,&count,&size);
 420         size = PAGE_ALIGN(size);
 421         dprintk(1,"reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
 422                 count, size, (count*size)>>PAGE_SHIFT);
 423
 424         retval = __videobuf_mmap_setup(q,count,size,req->memory);
 425         if (retval < 0) {
 426                 dprintk(1,"reqbufs: mmap setup returned %d\n",retval);
 427                 goto done;
 428         }
 429
 430         req->count = retval;
 431
 432  done:
 433         mutex_unlock(&q->lock);
 434         return retval;
 435 }
 436
 437 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 438 {
 439         int ret = -EINVAL;
 440
 441         mutex_lock(&q->lock);
 442         if (unlikely(b->type != q->type)) {
 443                 dprintk(1,"querybuf: Wrong type.\n");
 444                 goto done;
 445         }
 446         if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME)) {
 447                 dprintk(1,"querybuf: index out of range.\n");
 448                 goto done;
 449         }
 450         if (unlikely(NULL == q->bufs[b->index])) {
 451                 dprintk(1,"querybuf: buffer is null.\n");
 452                 goto done;
 453         }
 454
 455         videobuf_status(q,b,q->bufs[b->index],q->type);
 456
 457         ret = 0;
 458 done:
 459         mutex_unlock(&q->lock);
 460         return ret;
 461 }
 462
 463 int videobuf_qbuf(struct videobuf_queue *q,
 464               struct v4l2_buffer *b)
 465 {
 466         struct videobuf_buffer *buf;
 467         enum v4l2_field field;
 468         unsigned long flags=0;
 469         int retval;
 470
 471         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 472
 473         if (b->memory == V4L2_MEMORY_MMAP)
 474                 down_read(&current->mm->mmap_sem);
 475
 476         mutex_lock(&q->lock);
 477         retval = -EBUSY;
 478         if (q->reading) {
 479                 dprintk(1,"qbuf: Reading running...\n");
 480                 goto done;
 481         }
 482         retval = -EINVAL;
 483         if (b->type != q->type) {
 484                 dprintk(1,"qbuf: Wrong type.\n");
 485                 goto done;
 486         }
 487         if (b->index < 0 || b->index >= VIDEO_MAX_FRAME) {
 488                 dprintk(1,"qbuf: index out of range.\n");
 489                 goto done;
 490         }
 491         buf = q->bufs[b->index];
 492         if (NULL == buf) {
 493                 dprintk(1,"qbuf: buffer is null.\n");
 494                 goto done;
 495         }
 496         MAGIC_CHECK(buf->magic,MAGIC_BUFFER);
 497         if (buf->memory != b->memory) {
 498                 dprintk(1,"qbuf: memory type is wrong.\n");
 499                 goto done;
 500         }
 501         if (buf->state != STATE_NEEDS_INIT && buf->state != STATE_IDLE) {
 502                 dprintk(1,"qbuf: buffer is already queued or active.\n");
 503                 goto done;
 504         }
 505
 506         if (b->flags & V4L2_BUF_FLAG_INPUT) {
 507                 if (b->input >= q->inputs) {
 508                         dprintk(1,"qbuf: wrong input.\n");
 509                         goto done;
 510                 }
 511                 buf->input = b->input;
 512         } else {
 513                 buf->input = UNSET;
 514         }
 515
 516         switch (b->memory) {
 517         case V4L2_MEMORY_MMAP:
 518                 if (0 == buf->baddr) {
 519                         dprintk(1,"qbuf: mmap requested but buffer addr is zero!\n");
 520                         goto done;
 521                 }
 522                 break;
 523         case V4L2_MEMORY_USERPTR:
 524                 if (b->length < buf->bsize) {
 525                         dprintk(1,"qbuf: buffer length is not enough\n");
 526                         goto done;
 527                 }
 528                 if (STATE_NEEDS_INIT != buf->state && buf->baddr != b->m.userptr)
 529                         q->ops->buf_release(q,buf);
 530                 buf->baddr = b->m.userptr;
 531                 break;
 532         case V4L2_MEMORY_OVERLAY:
 533                 buf->boff = b->m.offset;
 534                 break;
 535         default:
 536                 dprintk(1,"qbuf: wrong memory type\n");
 537                 goto done;
 538         }
 539
 540         dprintk(1,"qbuf: requesting next field\n");
 541         field = videobuf_next_field(q);
 542         retval = q->ops->buf_prepare(q,buf,field);
 543         if (0 != retval) {
 544                 dprintk(1,"qbuf: buffer_prepare returned %d\n",retval);
 545                 goto done;
 546         }
 547
 548         list_add_tail(&buf->stream,&q->stream);
 549         if (q->streaming) {
 550                 if (q->irqlock)
 551                         spin_lock_irqsave(q->irqlock,flags);
 552                 q->ops->buf_queue(q,buf);
 553                 if (q->irqlock)
 554                         spin_unlock_irqrestore(q->irqlock,flags);
 555         }
 556         dprintk(1,"qbuf: succeded\n");
 557         retval = 0;
 558
 559  done:
 560         mutex_unlock(&q->lock);
 561
 562         if (b->memory == V4L2_MEMORY_MMAP)
 563                 up_read(&current->mm->mmap_sem);
 564
 565         return retval;
 566 }
 567
 568 int videobuf_dqbuf(struct videobuf_queue *q,
 569                struct v4l2_buffer *b, int nonblocking)
 570 {
 571         struct videobuf_buffer *buf;
 572         int retval;
 573
 574         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 575
 576         mutex_lock(&q->lock);
 577         retval = -EBUSY;
 578         if (q->reading) {
 579                 dprintk(1,"dqbuf: Reading running...\n");
 580                 goto done;
 581         }
 582         retval = -EINVAL;
 583         if (b->type != q->type) {
 584                 dprintk(1,"dqbuf: Wrong type.\n");
 585                 goto done;
 586         }
 587         if (list_empty(&q->stream)) {
 588                 dprintk(1,"dqbuf: stream running\n");
 589                 goto done;
 590         }
 591         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 592         retval = videobuf_waiton(buf, nonblocking, 1);
 593         if (retval < 0) {
 594                 dprintk(1,"dqbuf: waiton returned %d\n",retval);
 595                 goto done;
 596         }
 597         switch (buf->state) {
 598         case STATE_ERROR:
 599                 dprintk(1,"dqbuf: state is error\n");
 600                 retval = -EIO;
 601                 CALL(q,sync,q, buf);
 602                 buf->state = STATE_IDLE;
 603                 break;
 604         case STATE_DONE:
 605                 dprintk(1,"dqbuf: state is done\n");
 606                 CALL(q,sync,q, buf);
 607                 buf->state = STATE_IDLE;
 608                 break;
 609         default:
 610                 dprintk(1,"dqbuf: state invalid\n");
 611                 retval = -EINVAL;
 612                 goto done;
 613         }
 614         list_del(&buf->stream);
 615         memset(b,0,sizeof(*b));
 616         videobuf_status(q,b,buf,q->type);
 617
 618  done:
 619         mutex_unlock(&q->lock);
 620         return retval;
 621 }
 622
 623 int videobuf_streamon(struct videobuf_queue *q)
 624 {
 625         struct videobuf_buffer *buf;
 626         unsigned long flags=0;
 627         int retval;
 628
 629         mutex_lock(&q->lock);
 630         retval = -EBUSY;
 631         if (q->reading)
 632                 goto done;
 633         retval = 0;
 634         if (q->streaming)
 635                 goto done;
 636         q->streaming = 1;
 637         if (q->irqlock)
 638                 spin_lock_irqsave(q->irqlock,flags);
 639         list_for_each_entry(buf, &q->stream, stream)
 640                 if (buf->state == STATE_PREPARED)
 641                         q->ops->buf_queue(q,buf);
 642         if (q->irqlock)
 643                 spin_unlock_irqrestore(q->irqlock,flags);
 644
 645  done:
 646         mutex_unlock(&q->lock);
 647         return retval;
 648 }
 649
 650 /* Locking: Caller holds q->lock */
 651 static int __videobuf_streamoff(struct videobuf_queue *q)
 652 {
 653         if (!q->streaming)
 654                 return -EINVAL;
 655
 656         videobuf_queue_cancel(q);
 657         q->streaming = 0;
 658
 659         return 0;
 660 }
 661
 662 int videobuf_streamoff(struct videobuf_queue *q)
 663 {
 664         int retval;
 665
 666         mutex_lock(&q->lock);
 667         retval = __videobuf_streamoff(q);
 668         mutex_unlock(&q->lock);
 669
 670         return retval;
 671 }
 672
 673 /* Locking: Caller holds q->lock */
 674 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
 675                                       char __user *data,
 676                                       size_t count, loff_t *ppos)
 677 {
 678         enum v4l2_field field;
 679         unsigned long flags=0;
 680         int retval;
 681
 682         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 683
 684         /* setup stuff */
 685         q->read_buf = videobuf_alloc(q);
 686         if (NULL == q->read_buf)
 687                 return -ENOMEM;
 688
 689         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 690         q->read_buf->baddr  = (unsigned long)data;
 691         q->read_buf->bsize  = count;
 692
 693         field = videobuf_next_field(q);
 694         retval = q->ops->buf_prepare(q,q->read_buf,field);
 695         if (0 != retval)
 696                 goto done;
 697
 698         /* start capture & wait */
 699         if (q->irqlock)
 700                 spin_lock_irqsave(q->irqlock,flags);
 701         q->ops->buf_queue(q,q->read_buf);
 702         if (q->irqlock)
 703                 spin_unlock_irqrestore(q->irqlock,flags);
 704         retval = videobuf_waiton(q->read_buf,0,0);
 705         if (0 == retval) {
 706                 CALL(q,sync,q,q->read_buf);
 707                 if (STATE_ERROR == q->read_buf->state)
 708                         retval = -EIO;
 709                 else
 710                         retval = q->read_buf->size;
 711         }
 712
 713  done:
 714         /* cleanup */
 715         q->ops->buf_release(q,q->read_buf);
 716         kfree(q->read_buf);
 717         q->read_buf = NULL;
 718         return retval;
 719 }
 720
 721 ssize_t videobuf_read_one(struct videobuf_queue *q,
 722                           char __user *data, size_t count, loff_t *ppos,
 723                           int nonblocking)
 724 {
 725         enum v4l2_field field;
 726         unsigned long flags=0;
 727         unsigned size, nbufs;
 728         int retval;
 729
 730         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 731
 732         mutex_lock(&q->lock);
 733
 734         nbufs = 1; size = 0;
 735         q->ops->buf_setup(q,&nbufs,&size);
 736
 737         if (NULL == q->read_buf  &&
 738             count >= size        &&
 739             !nonblocking) {
 740                 retval = videobuf_read_zerocopy(q,data,count,ppos);
 741                 if (retval >= 0  ||  retval == -EIO)
 742                         /* ok, all done */
 743                         goto done;
 744                 /* fallback to kernel bounce buffer on failures */
 745         }
 746
 747         if (NULL == q->read_buf) {
 748                 /* need to capture a new frame */
 749                 retval = -ENOMEM;
 750                 q->read_buf = videobuf_alloc(q);
 751
 752                 dprintk(1,"video alloc=0x%p\n", q->read_buf);
 753                 if (NULL == q->read_buf)
 754                         goto done;
 755                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 756                 q->read_buf->bsize = count; /* preferred size */
 757                 field = videobuf_next_field(q);
 758                 retval = q->ops->buf_prepare(q,q->read_buf,field);
 759
 760                 if (0 != retval) {
 761                         kfree (q->read_buf);
 762                         q->read_buf = NULL;
 763                         goto done;
 764                 }
 765                 if (q->irqlock)
 766                         spin_lock_irqsave(q->irqlock,flags);
 767
 768                 q->ops->buf_queue(q,q->read_buf);
 769                 if (q->irqlock)
 770                         spin_unlock_irqrestore(q->irqlock,flags);
 771                 q->read_off = 0;
 772         }
 773
 774         /* wait until capture is done */
 775         retval = videobuf_waiton(q->read_buf, nonblocking, 1);
 776         if (0 != retval)
 777                 goto done;
 778
 779         CALL(q,sync,q,q->read_buf);
 780
 781         if (STATE_ERROR == q->read_buf->state) {
 782                 /* catch I/O errors */
 783                 q->ops->buf_release(q,q->read_buf);
 784                 kfree(q->read_buf);
 785                 q->read_buf = NULL;
 786                 retval = -EIO;
 787                 goto done;
 788         }
 789
 790         /* Copy to userspace */
 791         retval=CALL(q,video_copy_to_user,q,data,count,nonblocking);
 792         if (retval<0)
 793                 goto done;
 794
 795         q->read_off += retval;
 796         if (q->read_off == q->read_buf->size) {
 797                 /* all data copied, cleanup */
 798                 q->ops->buf_release(q,q->read_buf);
 799                 kfree(q->read_buf);
 800                 q->read_buf = NULL;
 801         }
 802
 803  done:
 804         mutex_unlock(&q->lock);
 805         return retval;
 806 }
 807
 808 /* Locking: Caller holds q->lock */
 809 int videobuf_read_start(struct videobuf_queue *q)
 810 {
 811         enum v4l2_field field;
 812         unsigned long flags=0;
 813         unsigned int count = 0, size = 0;
 814         int err, i;
 815
 816         q->ops->buf_setup(q,&count,&size);
 817         if (count < 2)
 818                 count = 2;
 819         if (count > VIDEO_MAX_FRAME)
 820                 count = VIDEO_MAX_FRAME;
 821         size = PAGE_ALIGN(size);
 822
 823         err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
 824         if (err < 0)
 825                 return err;
 826
 827         count = err;
 828
 829         for (i = 0; i < count; i++) {
 830                 field = videobuf_next_field(q);
 831                 err = q->ops->buf_prepare(q,q->bufs[i],field);
 832                 if (err)
 833                         return err;
 834                 list_add_tail(&q->bufs[i]->stream, &q->stream);
 835         }
 836         if (q->irqlock)
 837                 spin_lock_irqsave(q->irqlock,flags);
 838         for (i = 0; i < count; i++)
 839                 q->ops->buf_queue(q,q->bufs[i]);
 840         if (q->irqlock)
 841                 spin_unlock_irqrestore(q->irqlock,flags);
 842         q->reading = 1;
 843         return 0;
 844 }
 845
 846 static void __videobuf_read_stop(struct videobuf_queue *q)
 847 {
 848         int i;
 849
 850
 851         videobuf_queue_cancel(q);
 852         __videobuf_mmap_free(q);
 853         INIT_LIST_HEAD(&q->stream);
 854         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 855                 if (NULL == q->bufs[i])
 856                         continue;
 857                 kfree(q->bufs[i]);
 858                 q->bufs[i] = NULL;
 859         }
 860         q->read_buf = NULL;
 861         q->reading  = 0;
 862
 863 }
 864
 865 void videobuf_read_stop(struct videobuf_queue *q)
 866 {
 867         mutex_lock(&q->lock);
 868         __videobuf_read_stop(q);
 869         mutex_unlock(&q->lock);
 870 }
 871
 872 void videobuf_stop(struct videobuf_queue *q)
 873 {
 874         mutex_lock(&q->lock);
 875
 876         if (q->streaming)
 877                 __videobuf_streamoff(q);
 878
 879         if (q->reading)
 880                 __videobuf_read_stop(q);
 881
 882         mutex_unlock(&q->lock);
 883 }
 884
 885
 886 ssize_t videobuf_read_stream(struct videobuf_queue *q,
 887                              char __user *data, size_t count, loff_t *ppos,
 888                              int vbihack, int nonblocking)
 889 {
 890         int rc, retval;
 891         unsigned long flags=0;
 892
 893         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 894
 895         dprintk(2,"%s\n",__FUNCTION__);
 896         mutex_lock(&q->lock);
 897         retval = -EBUSY;
 898         if (q->streaming)
 899                 goto done;
 900         if (!q->reading) {
 901                 retval = videobuf_read_start(q);
 902                 if (retval < 0)
 903                         goto done;
 904         }
 905
 906         retval = 0;
 907         while (count > 0) {
 908                 /* get / wait for data */
 909                 if (NULL == q->read_buf) {
 910                         q->read_buf = list_entry(q->stream.next,
 911                                                  struct videobuf_buffer,
 912                                                  stream);
 913                         list_del(&q->read_buf->stream);
 914                         q->read_off = 0;
 915                 }
 916                 rc = videobuf_waiton(q->read_buf, nonblocking, 1);
 917                 if (rc < 0) {
 918                         if (0 == retval)
 919                                 retval = rc;
 920                         break;
 921                 }
 922
 923                 if (q->read_buf->state == STATE_DONE) {
 924                         rc = CALL (q,copy_stream, q, data + retval, count,
 925                                         retval, vbihack, nonblocking);
 926                         if (rc < 0) {
 927                                 retval = rc;
 928                                 break;
 929                         }
 930                         retval      += rc;
 931                         count       -= rc;
 932                         q->read_off += rc;
 933                 } else {
 934                         /* some error */
 935                         q->read_off = q->read_buf->size;
 936                         if (0 == retval)
 937                                 retval = -EIO;
 938                 }
 939
 940                 /* requeue buffer when done with copying */
 941                 if (q->read_off == q->read_buf->size) {
 942                         list_add_tail(&q->read_buf->stream,
 943                                       &q->stream);
 944                         if (q->irqlock)
 945                                 spin_lock_irqsave(q->irqlock,flags);
 946                         q->ops->buf_queue(q,q->read_buf);
 947                         if (q->irqlock)
 948                                 spin_unlock_irqrestore(q->irqlock,flags);
 949                         q->read_buf = NULL;
 950                 }
 951                 if (retval < 0)
 952                         break;
 953         }
 954
 955  done:
 956         mutex_unlock(&q->lock);
 957         return retval;
 958 }
 959
 960 unsigned int videobuf_poll_stream(struct file *file,
 961                                   struct videobuf_queue *q,
 962                                   poll_table *wait)
 963 {
 964         struct videobuf_buffer *buf = NULL;
 965         unsigned int rc = 0;
 966
 967         mutex_lock(&q->lock);
 968         if (q->streaming) {
 969                 if (!list_empty(&q->stream))
 970                         buf = list_entry(q->stream.next,
 971                                          struct videobuf_buffer, stream);
 972         } else {
 973                 if (!q->reading)
 974                         videobuf_read_start(q);
 975                 if (!q->reading) {
 976                         rc = POLLERR;
 977                 } else if (NULL == q->read_buf) {
 978                         q->read_buf = list_entry(q->stream.next,
 979                                                  struct videobuf_buffer,
 980                                                  stream);
 981                         list_del(&q->read_buf->stream);
 982                         q->read_off = 0;
 983                 }
 984                 buf = q->read_buf;
 985         }
 986         if (!buf)
 987                 rc = POLLERR;
 988
 989         if (0 == rc) {
 990                 poll_wait(file, &buf->done, wait);
 991                 if (buf->state == STATE_DONE ||
 992                     buf->state == STATE_ERROR)
 993                         rc = POLLIN|POLLRDNORM;
 994         }
 995         mutex_unlock(&q->lock);
 996         return rc;
 997 }
 998
 999 int videobuf_mmap_mapper(struct videobuf_queue *q,
1000                          struct vm_area_struct *vma)
1001 {
1002         int retval;
1003
1004         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
1005
1006         mutex_lock(&q->lock);
1007         retval=CALL(q,mmap_mapper,q,vma);
1008         mutex_unlock(&q->lock);
1009
1010         return retval;
1011 }
1012
1013 #ifdef CONFIG_VIDEO_V4L1_COMPAT
1014 int videobuf_cgmbuf(struct videobuf_queue *q,
1015                     struct video_mbuf *mbuf, int count)
1016 {
1017         struct v4l2_requestbuffers req;
1018         int rc,i;
1019
1020         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
1021
1022         memset(&req,0,sizeof(req));
1023         req.type   = q->type;
1024         req.count  = count;
1025         req.memory = V4L2_MEMORY_MMAP;
1026         rc = videobuf_reqbufs(q,&req);
1027         if (rc < 0)
1028                 return rc;
1029
1030         mbuf->frames = req.count;
1031         mbuf->size   = 0;
1032         for (i = 0; i < mbuf->frames; i++) {
1033                 mbuf->offsets[i]  = q->bufs[i]->boff;
1034                 mbuf->size       += q->bufs[i]->bsize;
1035         }
1036
1037         return 0;
1038 }
1039 EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
1040 #endif
1041
1042 /* --------------------------------------------------------------------- */
1043
1044 EXPORT_SYMBOL_GPL(videobuf_waiton);
1045 EXPORT_SYMBOL_GPL(videobuf_iolock);
1046
1047 EXPORT_SYMBOL_GPL(videobuf_alloc);
1048
1049 EXPORT_SYMBOL_GPL(videobuf_queue_core_init);
1050 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
1051 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
1052
1053 EXPORT_SYMBOL_GPL(videobuf_next_field);
1054 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
1055 EXPORT_SYMBOL_GPL(videobuf_querybuf);
1056 EXPORT_SYMBOL_GPL(videobuf_qbuf);
1057 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
1058 EXPORT_SYMBOL_GPL(videobuf_streamon);
1059 EXPORT_SYMBOL_GPL(videobuf_streamoff);
1060
1061 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1062 EXPORT_SYMBOL_GPL(videobuf_stop);
1063 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1064 EXPORT_SYMBOL_GPL(videobuf_read_one);
1065 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1066
1067 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
1068 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
1069 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
1070
1071 /*
1072  * Local variables:
1073  * c-basic-offset: 8
1074  * End:
1075  */