SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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) do {                                       \
  26         if (unlikely((is) != (should))) {                                  \
  27         printk(KERN_ERR "magic mismatch: %x (expected %x)\n", is, should); \
  28         BUG(); } } while (0)
  29
  30 static int debug;
  31 module_param(debug, int, 0644);
  32
  33 MODULE_DESCRIPTION("helper module to manage video4linux buffers");
  34 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
  35 MODULE_LICENSE("GPL");
  36
  37 #define dprintk(level, fmt, arg...) do {                        \
  38         if (debug >= level)                                     \
  39         printk(KERN_DEBUG "vbuf: " fmt , ## arg); } while (0)
  40
  41 /* --------------------------------------------------------------------- */
  42
  43 #define CALL(q, f, arg...)                                              \
  44         ((q->int_ops->f) ? q->int_ops->f(arg) : 0)
  45
  46 void *videobuf_alloc(struct videobuf_queue *q)
  47 {
  48         struct videobuf_buffer *vb;
  49
  50         BUG_ON(q->msize < sizeof(*vb));
  51
  52         if (!q->int_ops || !q->int_ops->alloc) {
  53                 printk(KERN_ERR "No specific ops defined!\n");
  54                 BUG();
  55         }
  56
  57         vb = q->int_ops->alloc(q->msize);
  58
  59         if (NULL != vb) {
  60                 init_waitqueue_head(&vb->done);
  61                 vb->magic     = MAGIC_BUFFER;
  62         }
  63
  64         return vb;
  65 }
  66
  67 #define WAITON_CONDITION (vb->state != VIDEOBUF_ACTIVE &&\
  68                                 vb->state != VIDEOBUF_QUEUED)
  69 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
  70 {
  71         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
  72
  73         if (non_blocking) {
  74                 if (WAITON_CONDITION)
  75                         return 0;
  76                 else
  77                         return -EAGAIN;
  78         }
  79
  80         if (intr)
  81                 return wait_event_interruptible(vb->done, WAITON_CONDITION);
  82         else
  83                 wait_event(vb->done, WAITON_CONDITION);
  84
  85         return 0;
  86 }
  87
  88 int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
  89                     struct v4l2_framebuffer *fbuf)
  90 {
  91         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
  92         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
  93
  94         /* This is required to avoid OOPS on some cases,
  95            since mmap_mapper() method should be called before _iolock.
  96            On some cases, the mmap_mapper() is called only after scheduling.
  97          */
  98         if (vb->memory == V4L2_MEMORY_MMAP) {
  99                 wait_event_timeout(vb->done, q->is_mmapped,
 100                                    msecs_to_jiffies(100));
 101                 if (!q->is_mmapped) {
 102                         printk(KERN_ERR
 103                                "Error: mmap_mapper() never called!\n");
 104                         return -EINVAL;
 105                 }
 106         }
 107
 108         return CALL(q, iolock, q, vb, fbuf);
 109 }
 110
 111 /* --------------------------------------------------------------------- */
 112
 113
 114 void videobuf_queue_core_init(struct videobuf_queue *q,
 115                          struct videobuf_queue_ops *ops,
 116                          struct device *dev,
 117                          spinlock_t *irqlock,
 118                          enum v4l2_buf_type type,
 119                          enum v4l2_field field,
 120                          unsigned int msize,
 121                          void *priv,
 122                          struct videobuf_qtype_ops *int_ops)
 123 {
 124         memset(q, 0, sizeof(*q));
 125         q->irqlock   = irqlock;
 126         q->dev       = dev;
 127         q->type      = type;
 128         q->field     = field;
 129         q->msize     = msize;
 130         q->ops       = ops;
 131         q->priv_data = priv;
 132         q->int_ops   = int_ops;
 133
 134         /* All buffer operations are mandatory */
 135         BUG_ON(!q->ops->buf_setup);
 136         BUG_ON(!q->ops->buf_prepare);
 137         BUG_ON(!q->ops->buf_queue);
 138         BUG_ON(!q->ops->buf_release);
 139
 140         /* Having implementations for abstract methods are mandatory */
 141         BUG_ON(!q->int_ops);
 142
 143         mutex_init(&q->vb_lock);
 144         init_waitqueue_head(&q->wait);
 145         INIT_LIST_HEAD(&q->stream);
 146 }
 147
 148 /* Locking: Only usage in bttv unsafe find way to remove */
 149 int videobuf_queue_is_busy(struct videobuf_queue *q)
 150 {
 151         int i;
 152
 153         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 154
 155         if (q->streaming) {
 156                 dprintk(1, "busy: streaming active\n");
 157                 return 1;
 158         }
 159         if (q->reading) {
 160                 dprintk(1, "busy: pending read #1\n");
 161                 return 1;
 162         }
 163         if (q->read_buf) {
 164                 dprintk(1, "busy: pending read #2\n");
 165                 return 1;
 166         }
 167         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 168                 if (NULL == q->bufs[i])
 169                         continue;
 170                 if (q->bufs[i]->map) {
 171                         dprintk(1, "busy: buffer #%d mapped\n", i);
 172                         return 1;
 173                 }
 174                 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
 175                         dprintk(1, "busy: buffer #%d queued\n", i);
 176                         return 1;
 177                 }
 178                 if (q->bufs[i]->state == VIDEOBUF_ACTIVE) {
 179                         dprintk(1, "busy: buffer #%d avtive\n", i);
 180                         return 1;
 181                 }
 182         }
 183         return 0;
 184 }
 185
 186 /* Locking: Caller holds q->vb_lock */
 187 void videobuf_queue_cancel(struct videobuf_queue *q)
 188 {
 189         unsigned long flags = 0;
 190         int i;
 191
 192         q->streaming = 0;
 193         q->reading  = 0;
 194         wake_up_interruptible_sync(&q->wait);
 195
 196         /* remove queued buffers from list */
 197         if (q->irqlock)
 198                 spin_lock_irqsave(q->irqlock, flags);
 199         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 200                 if (NULL == q->bufs[i])
 201                         continue;
 202                 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
 203                         list_del(&q->bufs[i]->queue);
 204                         q->bufs[i]->state = VIDEOBUF_ERROR;
 205                         wake_up_all(&q->bufs[i]->done);
 206                 }
 207         }
 208         if (q->irqlock)
 209                 spin_unlock_irqrestore(q->irqlock, flags);
 210
 211         /* free all buffers + clear queue */
 212         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 213                 if (NULL == q->bufs[i])
 214                         continue;
 215                 q->ops->buf_release(q, q->bufs[i]);
 216         }
 217         INIT_LIST_HEAD(&q->stream);
 218 }
 219
 220 /* --------------------------------------------------------------------- */
 221
 222 /* Locking: Caller holds q->vb_lock */
 223 enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
 224 {
 225         enum v4l2_field field = q->field;
 226
 227         BUG_ON(V4L2_FIELD_ANY == field);
 228
 229         if (V4L2_FIELD_ALTERNATE == field) {
 230                 if (V4L2_FIELD_TOP == q->last) {
 231                         field   = V4L2_FIELD_BOTTOM;
 232                         q->last = V4L2_FIELD_BOTTOM;
 233                 } else {
 234                         field   = V4L2_FIELD_TOP;
 235                         q->last = V4L2_FIELD_TOP;
 236                 }
 237         }
 238         return field;
 239 }
 240
 241 /* Locking: Caller holds q->vb_lock */
 242 static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
 243                             struct videobuf_buffer *vb, enum v4l2_buf_type type)
 244 {
 245         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
 246         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 247
 248         b->index    = vb->i;
 249         b->type     = type;
 250
 251         b->memory   = vb->memory;
 252         switch (b->memory) {
 253         case V4L2_MEMORY_MMAP:
 254                 b->m.offset  = vb->boff;
 255                 b->length    = vb->bsize;
 256                 break;
 257         case V4L2_MEMORY_USERPTR:
 258                 b->m.userptr = vb->baddr;
 259                 b->length    = vb->bsize;
 260                 break;
 261         case V4L2_MEMORY_OVERLAY:
 262                 b->m.offset  = vb->boff;
 263                 break;
 264         }
 265
 266         b->flags    = 0;
 267         if (vb->map)
 268                 b->flags |= V4L2_BUF_FLAG_MAPPED;
 269
 270         switch (vb->state) {
 271         case VIDEOBUF_PREPARED:
 272         case VIDEOBUF_QUEUED:
 273         case VIDEOBUF_ACTIVE:
 274                 b->flags |= V4L2_BUF_FLAG_QUEUED;
 275                 break;
 276         case VIDEOBUF_DONE:
 277         case VIDEOBUF_ERROR:
 278                 b->flags |= V4L2_BUF_FLAG_DONE;
 279                 break;
 280         case VIDEOBUF_NEEDS_INIT:
 281         case VIDEOBUF_IDLE:
 282                 /* nothing */
 283                 break;
 284         }
 285
 286         if (vb->input != UNSET) {
 287                 b->flags |= V4L2_BUF_FLAG_INPUT;
 288                 b->input  = vb->input;
 289         }
 290
 291         b->field     = vb->field;
 292         b->timestamp = vb->ts;
 293         b->bytesused = vb->size;
 294         b->sequence  = vb->field_count >> 1;
 295 }
 296
 297 /* Locking: Caller holds q->vb_lock */
 298 static int __videobuf_mmap_free(struct videobuf_queue *q)
 299 {
 300         int i;
 301         int rc;
 302
 303         if (!q)
 304                 return 0;
 305
 306         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 307
 308
 309         rc  = CALL(q, mmap_free, q);
 310
 311         q->is_mmapped = 0;
 312
 313         if (rc < 0)
 314                 return rc;
 315
 316         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 317                 if (NULL == q->bufs[i])
 318                         continue;
 319                 q->ops->buf_release(q, q->bufs[i]);
 320                 kfree(q->bufs[i]);
 321                 q->bufs[i] = NULL;
 322         }
 323
 324         return rc;
 325 }
 326
 327 int videobuf_mmap_free(struct videobuf_queue *q)
 328 {
 329         int ret;
 330         mutex_lock(&q->vb_lock);
 331         ret = __videobuf_mmap_free(q);
 332         mutex_unlock(&q->vb_lock);
 333         return ret;
 334 }
 335
 336 /* Locking: Caller holds q->vb_lock */
 337 static int __videobuf_mmap_setup(struct videobuf_queue *q,
 338                         unsigned int bcount, unsigned int bsize,
 339                         enum v4l2_memory memory)
 340 {
 341         unsigned int i;
 342         int err;
 343
 344         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 345
 346         err = __videobuf_mmap_free(q);
 347         if (0 != err)
 348                 return err;
 349
 350         /* Allocate and initialize buffers */
 351         for (i = 0; i < bcount; i++) {
 352                 q->bufs[i] = videobuf_alloc(q);
 353
 354                 if (q->bufs[i] == NULL)
 355                         break;
 356
 357                 q->bufs[i]->i      = i;
 358                 q->bufs[i]->input  = UNSET;
 359                 q->bufs[i]->memory = memory;
 360                 q->bufs[i]->bsize  = bsize;
 361                 switch (memory) {
 362                 case V4L2_MEMORY_MMAP:
 363                         q->bufs[i]->boff  = bsize * i;
 364                         break;
 365                 case V4L2_MEMORY_USERPTR:
 366                 case V4L2_MEMORY_OVERLAY:
 367                         /* nothing */
 368                         break;
 369                 }
 370         }
 371
 372         if (!i)
 373                 return -ENOMEM;
 374
 375         dprintk(1, "mmap setup: %d buffers, %d bytes each\n",
 376                 i, bsize);
 377
 378         return i;
 379 }
 380
 381 int videobuf_mmap_setup(struct videobuf_queue *q,
 382                         unsigned int bcount, unsigned int bsize,
 383                         enum v4l2_memory memory)
 384 {
 385         int ret;
 386         mutex_lock(&q->vb_lock);
 387         ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
 388         mutex_unlock(&q->vb_lock);
 389         return ret;
 390 }
 391
 392 int videobuf_reqbufs(struct videobuf_queue *q,
 393                  struct v4l2_requestbuffers *req)
 394 {
 395         unsigned int size, count;
 396         int retval;
 397
 398         if (req->count < 1) {
 399                 dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
 400                 return -EINVAL;
 401         }
 402
 403         if (req->memory != V4L2_MEMORY_MMAP     &&
 404             req->memory != V4L2_MEMORY_USERPTR  &&
 405             req->memory != V4L2_MEMORY_OVERLAY) {
 406                 dprintk(1, "reqbufs: memory type invalid\n");
 407                 return -EINVAL;
 408         }
 409
 410         mutex_lock(&q->vb_lock);
 411         if (req->type != q->type) {
 412                 dprintk(1, "reqbufs: queue type invalid\n");
 413                 retval = -EINVAL;
 414                 goto done;
 415         }
 416
 417         if (q->streaming) {
 418                 dprintk(1, "reqbufs: streaming already exists\n");
 419                 retval = -EBUSY;
 420                 goto done;
 421         }
 422         if (!list_empty(&q->stream)) {
 423                 dprintk(1, "reqbufs: stream running\n");
 424                 retval = -EBUSY;
 425                 goto done;
 426         }
 427
 428         count = req->count;
 429         if (count > VIDEO_MAX_FRAME)
 430                 count = VIDEO_MAX_FRAME;
 431         size = 0;
 432         q->ops->buf_setup(q, &count, &size);
 433         size = PAGE_ALIGN(size);
 434         dprintk(1, "reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
 435                 count, size, (count*size)>>PAGE_SHIFT);
 436
 437         retval = __videobuf_mmap_setup(q, count, size, req->memory);
 438         if (retval < 0) {
 439                 dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
 440                 goto done;
 441         }
 442
 443         req->count = retval;
 444
 445  done:
 446         mutex_unlock(&q->vb_lock);
 447         return retval;
 448 }
 449
 450 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 451 {
 452         int ret = -EINVAL;
 453
 454         mutex_lock(&q->vb_lock);
 455         if (unlikely(b->type != q->type)) {
 456                 dprintk(1, "querybuf: Wrong type.\n");
 457                 goto done;
 458         }
 459         if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME)) {
 460                 dprintk(1, "querybuf: index out of range.\n");
 461                 goto done;
 462         }
 463         if (unlikely(NULL == q->bufs[b->index])) {
 464                 dprintk(1, "querybuf: buffer is null.\n");
 465                 goto done;
 466         }
 467
 468         videobuf_status(q, b, q->bufs[b->index], q->type);
 469
 470         ret = 0;
 471 done:
 472         mutex_unlock(&q->vb_lock);
 473         return ret;
 474 }
 475
 476 int videobuf_qbuf(struct videobuf_queue *q,
 477               struct v4l2_buffer *b)
 478 {
 479         struct videobuf_buffer *buf;
 480         enum v4l2_field field;
 481         unsigned long flags = 0;
 482         int retval;
 483
 484         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 485
 486         if (b->memory == V4L2_MEMORY_MMAP)
 487                 down_read(&current->mm->mmap_sem);
 488
 489         mutex_lock(&q->vb_lock);
 490         retval = -EBUSY;
 491         if (q->reading) {
 492                 dprintk(1, "qbuf: Reading running...\n");
 493                 goto done;
 494         }
 495         retval = -EINVAL;
 496         if (b->type != q->type) {
 497                 dprintk(1, "qbuf: Wrong type.\n");
 498                 goto done;
 499         }
 500         if (b->index < 0 || b->index >= VIDEO_MAX_FRAME) {
 501                 dprintk(1, "qbuf: index out of range.\n");
 502                 goto done;
 503         }
 504         buf = q->bufs[b->index];
 505         if (NULL == buf) {
 506                 dprintk(1, "qbuf: buffer is null.\n");
 507                 goto done;
 508         }
 509         MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
 510         if (buf->memory != b->memory) {
 511                 dprintk(1, "qbuf: memory type is wrong.\n");
 512                 goto done;
 513         }
 514         if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
 515                 dprintk(1, "qbuf: buffer is already queued or active.\n");
 516                 goto done;
 517         }
 518
 519         if (b->flags & V4L2_BUF_FLAG_INPUT) {
 520                 if (b->input >= q->inputs) {
 521                         dprintk(1, "qbuf: wrong input.\n");
 522                         goto done;
 523                 }
 524                 buf->input = b->input;
 525         } else {
 526                 buf->input = UNSET;
 527         }
 528
 529         switch (b->memory) {
 530         case V4L2_MEMORY_MMAP:
 531                 if (0 == buf->baddr) {
 532                         dprintk(1, "qbuf: mmap requested "
 533                                    "but buffer addr is zero!\n");
 534                         goto done;
 535                 }
 536                 break;
 537         case V4L2_MEMORY_USERPTR:
 538                 if (b->length < buf->bsize) {
 539                         dprintk(1, "qbuf: buffer length is not enough\n");
 540                         goto done;
 541                 }
 542                 if (VIDEOBUF_NEEDS_INIT != buf->state &&
 543                     buf->baddr != b->m.userptr)
 544                         q->ops->buf_release(q, buf);
 545                 buf->baddr = b->m.userptr;
 546                 break;
 547         case V4L2_MEMORY_OVERLAY:
 548                 buf->boff = b->m.offset;
 549                 break;
 550         default:
 551                 dprintk(1, "qbuf: wrong memory type\n");
 552                 goto done;
 553         }
 554
 555         dprintk(1, "qbuf: requesting next field\n");
 556         field = videobuf_next_field(q);
 557         retval = q->ops->buf_prepare(q, buf, field);
 558         if (0 != retval) {
 559                 dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
 560                 goto done;
 561         }
 562
 563         list_add_tail(&buf->stream, &q->stream);
 564         if (q->streaming) {
 565                 if (q->irqlock)
 566                         spin_lock_irqsave(q->irqlock, flags);
 567                 q->ops->buf_queue(q, buf);
 568                 if (q->irqlock)
 569                         spin_unlock_irqrestore(q->irqlock, flags);
 570         }
 571         dprintk(1, "qbuf: succeded\n");
 572         retval = 0;
 573         wake_up_interruptible_sync(&q->wait);
 574
 575  done:
 576         mutex_unlock(&q->vb_lock);
 577
 578         if (b->memory == V4L2_MEMORY_MMAP)
 579                 up_read(&current->mm->mmap_sem);
 580
 581         return retval;
 582 }
 583
 584
 585 /* Locking: Caller holds q->vb_lock */
 586 static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
 587 {
 588         int retval;
 589
 590 checks:
 591         if (!q->streaming) {
 592                 dprintk(1, "next_buffer: Not streaming\n");
 593                 retval = -EINVAL;
 594                 goto done;
 595         }
 596
 597         if (list_empty(&q->stream)) {
 598                 if (noblock) {
 599                         retval = -EAGAIN;
 600                         dprintk(2, "next_buffer: no buffers to dequeue\n");
 601                         goto done;
 602                 } else {
 603                         dprintk(2, "next_buffer: waiting on buffer\n");
 604
 605                         /* Drop lock to avoid deadlock with qbuf */
 606                         mutex_unlock(&q->vb_lock);
 607
 608                         /* Checking list_empty and streaming is safe without
 609                          * locks because we goto checks to validate while
 610                          * holding locks before proceeding */
 611                         retval = wait_event_interruptible(q->wait,
 612                                 !list_empty(&q->stream) || !q->streaming);
 613                         mutex_lock(&q->vb_lock);
 614
 615                         if (retval)
 616                                 goto done;
 617
 618                         goto checks;
 619                 }
 620         }
 621
 622         retval = 0;
 623
 624 done:
 625         return retval;
 626 }
 627
 628
 629 /* Locking: Caller holds q->vb_lock */
 630 static int stream_next_buffer(struct videobuf_queue *q,
 631                         struct videobuf_buffer **vb, int nonblocking)
 632 {
 633         int retval;
 634         struct videobuf_buffer *buf = NULL;
 635
 636         retval = stream_next_buffer_check_queue(q, nonblocking);
 637         if (retval)
 638                 goto done;
 639
 640         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 641         retval = videobuf_waiton(buf, nonblocking, 1);
 642         if (retval < 0)
 643                 goto done;
 644
 645         *vb = buf;
 646 done:
 647         return retval;
 648 }
 649
 650 int videobuf_dqbuf(struct videobuf_queue *q,
 651                struct v4l2_buffer *b, int nonblocking)
 652 {
 653         struct videobuf_buffer *buf = NULL;
 654         int retval;
 655
 656         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 657
 658         mutex_lock(&q->vb_lock);
 659
 660         retval = stream_next_buffer(q, &buf, nonblocking);
 661         if (retval < 0) {
 662                 dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
 663                 goto done;
 664         }
 665
 666         switch (buf->state) {
 667         case VIDEOBUF_ERROR:
 668                 dprintk(1, "dqbuf: state is error\n");
 669                 retval = -EIO;
 670                 CALL(q, sync, q, buf);
 671                 buf->state = VIDEOBUF_IDLE;
 672                 break;
 673         case VIDEOBUF_DONE:
 674                 dprintk(1, "dqbuf: state is done\n");
 675                 CALL(q, sync, q, buf);
 676                 buf->state = VIDEOBUF_IDLE;
 677                 break;
 678         default:
 679                 dprintk(1, "dqbuf: state invalid\n");
 680                 retval = -EINVAL;
 681                 goto done;
 682         }
 683         list_del(&buf->stream);
 684         memset(b, 0, sizeof(*b));
 685         videobuf_status(q, b, buf, q->type);
 686
 687  done:
 688         mutex_unlock(&q->vb_lock);
 689         return retval;
 690 }
 691
 692 int videobuf_streamon(struct videobuf_queue *q)
 693 {
 694         struct videobuf_buffer *buf;
 695         unsigned long flags = 0;
 696         int retval;
 697
 698         mutex_lock(&q->vb_lock);
 699         retval = -EBUSY;
 700         if (q->reading)
 701                 goto done;
 702         retval = 0;
 703         if (q->streaming)
 704                 goto done;
 705         q->streaming = 1;
 706         if (q->irqlock)
 707                 spin_lock_irqsave(q->irqlock, flags);
 708         list_for_each_entry(buf, &q->stream, stream)
 709                 if (buf->state == VIDEOBUF_PREPARED)
 710                         q->ops->buf_queue(q, buf);
 711         if (q->irqlock)
 712                 spin_unlock_irqrestore(q->irqlock, flags);
 713
 714         wake_up_interruptible_sync(&q->wait);
 715  done:
 716         mutex_unlock(&q->vb_lock);
 717         return retval;
 718 }
 719
 720 /* Locking: Caller holds q->vb_lock */
 721 static int __videobuf_streamoff(struct videobuf_queue *q)
 722 {
 723         if (!q->streaming)
 724                 return -EINVAL;
 725
 726         videobuf_queue_cancel(q);
 727
 728         return 0;
 729 }
 730
 731 int videobuf_streamoff(struct videobuf_queue *q)
 732 {
 733         int retval;
 734
 735         mutex_lock(&q->vb_lock);
 736         retval = __videobuf_streamoff(q);
 737         mutex_unlock(&q->vb_lock);
 738
 739         return retval;
 740 }
 741
 742 /* Locking: Caller holds q->vb_lock */
 743 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
 744                                       char __user *data,
 745                                       size_t count, loff_t *ppos)
 746 {
 747         enum v4l2_field field;
 748         unsigned long flags = 0;
 749         int retval;
 750
 751         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 752
 753         /* setup stuff */
 754         q->read_buf = videobuf_alloc(q);
 755         if (NULL == q->read_buf)
 756                 return -ENOMEM;
 757
 758         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 759         q->read_buf->baddr  = (unsigned long)data;
 760         q->read_buf->bsize  = count;
 761
 762         field = videobuf_next_field(q);
 763         retval = q->ops->buf_prepare(q, q->read_buf, field);
 764         if (0 != retval)
 765                 goto done;
 766
 767         /* start capture & wait */
 768         if (q->irqlock)
 769                 spin_lock_irqsave(q->irqlock, flags);
 770         q->ops->buf_queue(q, q->read_buf);
 771         if (q->irqlock)
 772                 spin_unlock_irqrestore(q->irqlock, flags);
 773         retval = videobuf_waiton(q->read_buf, 0, 0);
 774         if (0 == retval) {
 775                 CALL(q, sync, q, q->read_buf);
 776                 if (VIDEOBUF_ERROR == q->read_buf->state)
 777                         retval = -EIO;
 778                 else
 779                         retval = q->read_buf->size;
 780         }
 781
 782  done:
 783         /* cleanup */
 784         q->ops->buf_release(q, q->read_buf);
 785         kfree(q->read_buf);
 786         q->read_buf = NULL;
 787         return retval;
 788 }
 789
 790 ssize_t videobuf_read_one(struct videobuf_queue *q,
 791                           char __user *data, size_t count, loff_t *ppos,
 792                           int nonblocking)
 793 {
 794         enum v4l2_field field;
 795         unsigned long flags = 0;
 796         unsigned size = 0, nbufs = 1;
 797         int retval;
 798
 799         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 800
 801         mutex_lock(&q->vb_lock);
 802
 803         q->ops->buf_setup(q, &nbufs, &size);
 804
 805         if (NULL == q->read_buf  &&
 806             count >= size        &&
 807             !nonblocking) {
 808                 retval = videobuf_read_zerocopy(q, data, count, ppos);
 809                 if (retval >= 0  ||  retval == -EIO)
 810                         /* ok, all done */
 811                         goto done;
 812                 /* fallback to kernel bounce buffer on failures */
 813         }
 814
 815         if (NULL == q->read_buf) {
 816                 /* need to capture a new frame */
 817                 retval = -ENOMEM;
 818                 q->read_buf = videobuf_alloc(q);
 819
 820                 dprintk(1, "video alloc=0x%p\n", q->read_buf);
 821                 if (NULL == q->read_buf)
 822                         goto done;
 823                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 824                 q->read_buf->bsize = count; /* preferred size */
 825                 field = videobuf_next_field(q);
 826                 retval = q->ops->buf_prepare(q, q->read_buf, field);
 827
 828                 if (0 != retval) {
 829                         kfree(q->read_buf);
 830                         q->read_buf = NULL;
 831                         goto done;
 832                 }
 833                 if (q->irqlock)
 834                         spin_lock_irqsave(q->irqlock, flags);
 835
 836                 q->ops->buf_queue(q, q->read_buf);
 837                 if (q->irqlock)
 838                         spin_unlock_irqrestore(q->irqlock, flags);
 839                 q->read_off = 0;
 840         }
 841
 842         /* wait until capture is done */
 843         retval = videobuf_waiton(q->read_buf, nonblocking, 1);
 844         if (0 != retval)
 845                 goto done;
 846
 847         CALL(q, sync, q, q->read_buf);
 848
 849         if (VIDEOBUF_ERROR == q->read_buf->state) {
 850                 /* catch I/O errors */
 851                 q->ops->buf_release(q, q->read_buf);
 852                 kfree(q->read_buf);
 853                 q->read_buf = NULL;
 854                 retval = -EIO;
 855                 goto done;
 856         }
 857
 858         /* Copy to userspace */
 859         retval = CALL(q, video_copy_to_user, q, data, count, nonblocking);
 860         if (retval < 0)
 861                 goto done;
 862
 863         q->read_off += retval;
 864         if (q->read_off == q->read_buf->size) {
 865                 /* all data copied, cleanup */
 866                 q->ops->buf_release(q, q->read_buf);
 867                 kfree(q->read_buf);
 868                 q->read_buf = NULL;
 869         }
 870
 871  done:
 872         mutex_unlock(&q->vb_lock);
 873         return retval;
 874 }
 875
 876 /* Locking: Caller holds q->vb_lock */
 877 static int __videobuf_read_start(struct videobuf_queue *q)
 878 {
 879         enum v4l2_field field;
 880         unsigned long flags = 0;
 881         unsigned int count = 0, size = 0;
 882         int err, i;
 883
 884         q->ops->buf_setup(q, &count, &size);
 885         if (count < 2)
 886                 count = 2;
 887         if (count > VIDEO_MAX_FRAME)
 888                 count = VIDEO_MAX_FRAME;
 889         size = PAGE_ALIGN(size);
 890
 891         err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
 892         if (err < 0)
 893                 return err;
 894
 895         count = err;
 896
 897         for (i = 0; i < count; i++) {
 898                 field = videobuf_next_field(q);
 899                 err = q->ops->buf_prepare(q, q->bufs[i], field);
 900                 if (err)
 901                         return err;
 902                 list_add_tail(&q->bufs[i]->stream, &q->stream);
 903         }
 904         if (q->irqlock)
 905                 spin_lock_irqsave(q->irqlock, flags);
 906         for (i = 0; i < count; i++)
 907                 q->ops->buf_queue(q, q->bufs[i]);
 908         if (q->irqlock)
 909                 spin_unlock_irqrestore(q->irqlock, flags);
 910         q->reading = 1;
 911         return 0;
 912 }
 913
 914 static void __videobuf_read_stop(struct videobuf_queue *q)
 915 {
 916         int i;
 917
 918
 919         videobuf_queue_cancel(q);
 920         __videobuf_mmap_free(q);
 921         INIT_LIST_HEAD(&q->stream);
 922         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 923                 if (NULL == q->bufs[i])
 924                         continue;
 925                 kfree(q->bufs[i]);
 926                 q->bufs[i] = NULL;
 927         }
 928         q->read_buf = NULL;
 929
 930 }
 931
 932 int videobuf_read_start(struct videobuf_queue *q)
 933 {
 934         int rc;
 935
 936         mutex_lock(&q->vb_lock);
 937         rc = __videobuf_read_start(q);
 938         mutex_unlock(&q->vb_lock);
 939
 940         return rc;
 941 }
 942
 943 void videobuf_read_stop(struct videobuf_queue *q)
 944 {
 945         mutex_lock(&q->vb_lock);
 946         __videobuf_read_stop(q);
 947         mutex_unlock(&q->vb_lock);
 948 }
 949
 950 void videobuf_stop(struct videobuf_queue *q)
 951 {
 952         mutex_lock(&q->vb_lock);
 953
 954         if (q->streaming)
 955                 __videobuf_streamoff(q);
 956
 957         if (q->reading)
 958                 __videobuf_read_stop(q);
 959
 960         mutex_unlock(&q->vb_lock);
 961 }
 962
 963
 964 ssize_t videobuf_read_stream(struct videobuf_queue *q,
 965                              char __user *data, size_t count, loff_t *ppos,
 966                              int vbihack, int nonblocking)
 967 {
 968         int rc, retval;
 969         unsigned long flags = 0;
 970
 971         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 972
 973         dprintk(2, "%s\n", __func__);
 974         mutex_lock(&q->vb_lock);
 975         retval = -EBUSY;
 976         if (q->streaming)
 977                 goto done;
 978         if (!q->reading) {
 979                 retval = __videobuf_read_start(q);
 980                 if (retval < 0)
 981                         goto done;
 982         }
 983
 984         retval = 0;
 985         while (count > 0) {
 986                 /* get / wait for data */
 987                 if (NULL == q->read_buf) {
 988                         q->read_buf = list_entry(q->stream.next,
 989                                                  struct videobuf_buffer,
 990                                                  stream);
 991                         list_del(&q->read_buf->stream);
 992                         q->read_off = 0;
 993                 }
 994                 rc = videobuf_waiton(q->read_buf, nonblocking, 1);
 995                 if (rc < 0) {
 996                         if (0 == retval)
 997                                 retval = rc;
 998                         break;
 999                 }
1000
1001                 if (q->read_buf->state == VIDEOBUF_DONE) {
1002                         rc = CALL(q, copy_stream, q, data + retval, count,
1003                                         retval, vbihack, nonblocking);
1004                         if (rc < 0) {
1005                                 retval = rc;
1006                                 break;
1007                         }
1008                         retval      += rc;
1009                         count       -= rc;
1010                         q->read_off += rc;
1011                 } else {
1012                         /* some error */
1013                         q->read_off = q->read_buf->size;
1014                         if (0 == retval)
1015                                 retval = -EIO;
1016                 }
1017
1018                 /* requeue buffer when done with copying */
1019                 if (q->read_off == q->read_buf->size) {
1020                         list_add_tail(&q->read_buf->stream,
1021                                       &q->stream);
1022                         if (q->irqlock)
1023                                 spin_lock_irqsave(q->irqlock, flags);
1024                         q->ops->buf_queue(q, q->read_buf);
1025                         if (q->irqlock)
1026                                 spin_unlock_irqrestore(q->irqlock, flags);
1027                         q->read_buf = NULL;
1028                 }
1029                 if (retval < 0)
1030                         break;
1031         }
1032
1033  done:
1034         mutex_unlock(&q->vb_lock);
1035         return retval;
1036 }
1037
1038 unsigned int videobuf_poll_stream(struct file *file,
1039                                   struct videobuf_queue *q,
1040                                   poll_table *wait)
1041 {
1042         struct videobuf_buffer *buf = NULL;
1043         unsigned int rc = 0;
1044
1045         mutex_lock(&q->vb_lock);
1046         if (q->streaming) {
1047                 if (!list_empty(&q->stream))
1048                         buf = list_entry(q->stream.next,
1049                                          struct videobuf_buffer, stream);
1050         } else {
1051                 if (!q->reading)
1052                         __videobuf_read_start(q);
1053                 if (!q->reading) {
1054                         rc = POLLERR;
1055                 } else if (NULL == q->read_buf) {
1056                         q->read_buf = list_entry(q->stream.next,
1057                                                  struct videobuf_buffer,
1058                                                  stream);
1059                         list_del(&q->read_buf->stream);
1060                         q->read_off = 0;
1061                 }
1062                 buf = q->read_buf;
1063         }
1064         if (!buf)
1065                 rc = POLLERR;
1066
1067         if (0 == rc) {
1068                 poll_wait(file, &buf->done, wait);
1069                 if (buf->state == VIDEOBUF_DONE ||
1070                     buf->state == VIDEOBUF_ERROR)
1071                         rc = POLLIN|POLLRDNORM;
1072         }
1073         mutex_unlock(&q->vb_lock);
1074         return rc;
1075 }
1076
1077 int videobuf_mmap_mapper(struct videobuf_queue *q,
1078                          struct vm_area_struct *vma)
1079 {
1080         int retval;
1081
1082         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1083
1084         mutex_lock(&q->vb_lock);
1085         retval = CALL(q, mmap_mapper, q, vma);
1086         q->is_mmapped = 1;
1087         mutex_unlock(&q->vb_lock);
1088
1089         return retval;
1090 }
1091
1092 #ifdef CONFIG_VIDEO_V4L1_COMPAT
1093 int videobuf_cgmbuf(struct videobuf_queue *q,
1094                     struct video_mbuf *mbuf, int count)
1095 {
1096         struct v4l2_requestbuffers req;
1097         int rc, i;
1098
1099         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1100
1101         memset(&req, 0, sizeof(req));
1102         req.type   = q->type;
1103         req.count  = count;
1104         req.memory = V4L2_MEMORY_MMAP;
1105         rc = videobuf_reqbufs(q, &req);
1106         if (rc < 0)
1107                 return rc;
1108
1109         mbuf->frames = req.count;
1110         mbuf->size   = 0;
1111         for (i = 0; i < mbuf->frames; i++) {
1112                 mbuf->offsets[i]  = q->bufs[i]->boff;
1113                 mbuf->size       += q->bufs[i]->bsize;
1114         }
1115
1116         return 0;
1117 }
1118 EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
1119 #endif
1120
1121 /* --------------------------------------------------------------------- */
1122
1123 EXPORT_SYMBOL_GPL(videobuf_waiton);
1124 EXPORT_SYMBOL_GPL(videobuf_iolock);
1125
1126 EXPORT_SYMBOL_GPL(videobuf_alloc);
1127
1128 EXPORT_SYMBOL_GPL(videobuf_queue_core_init);
1129 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
1130 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
1131
1132 EXPORT_SYMBOL_GPL(videobuf_next_field);
1133 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
1134 EXPORT_SYMBOL_GPL(videobuf_querybuf);
1135 EXPORT_SYMBOL_GPL(videobuf_qbuf);
1136 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
1137 EXPORT_SYMBOL_GPL(videobuf_streamon);
1138 EXPORT_SYMBOL_GPL(videobuf_streamoff);
1139
1140 EXPORT_SYMBOL_GPL(videobuf_read_start);
1141 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1142 EXPORT_SYMBOL_GPL(videobuf_stop);
1143 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1144 EXPORT_SYMBOL_GPL(videobuf_read_one);
1145 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1146
1147 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
1148 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
1149 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);