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/mm.h>
  20 #include <linux/sched.h>
  21 #include <linux/slab.h>
  22 #include <linux/interrupt.h>
  23
  24 #include <media/videobuf-core.h>
  25
  26 #define MAGIC_BUFFER 0x20070728
  27 #define MAGIC_CHECK(is, should)                                         \
  28         do {                                                            \
  29                 if (unlikely((is) != (should))) {                       \
  30                         printk(KERN_ERR                                 \
  31                                 "magic mismatch: %x (expected %x)\n",   \
  32                                         is, should);                    \
  33                         BUG();                                          \
  34                 }                                                       \
  35         } while (0)
  36
  37 static int debug;
  38 module_param(debug, int, 0644);
  39
  40 MODULE_DESCRIPTION("helper module to manage video4linux buffers");
  41 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
  42 MODULE_LICENSE("GPL");
  43
  44 #define dprintk(level, fmt, arg...)                                     \
  45         do {                                                            \
  46                 if (debug >= level)                                     \
  47                         printk(KERN_DEBUG "vbuf: " fmt, ## arg);        \
  48         } while (0)
  49
  50 /* --------------------------------------------------------------------- */
  51
  52 #define CALL(q, f, arg...)                                              \
  53         ((q->int_ops->f) ? q->int_ops->f(arg) : 0)
  54
  55 struct videobuf_buffer *videobuf_alloc(struct videobuf_queue *q)
  56 {
  57         struct videobuf_buffer *vb;
  58
  59         BUG_ON(q->msize < sizeof(*vb));
  60
  61         if (!q->int_ops || !q->int_ops->alloc) {
  62                 printk(KERN_ERR "No specific ops defined!\n");
  63                 BUG();
  64         }
  65
  66         vb = q->int_ops->alloc(q->msize);
  67         if (NULL != vb) {
  68                 init_waitqueue_head(&vb->done);
  69                 vb->magic = MAGIC_BUFFER;
  70         }
  71
  72         return vb;
  73 }
  74 EXPORT_SYMBOL_GPL(videobuf_alloc);
  75
  76 #define WAITON_CONDITION (vb->state != VIDEOBUF_ACTIVE &&\
  77                                 vb->state != VIDEOBUF_QUEUED)
  78 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
  79 {
  80         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
  81
  82         if (non_blocking) {
  83                 if (WAITON_CONDITION)
  84                         return 0;
  85                 else
  86                         return -EAGAIN;
  87         }
  88
  89         if (intr)
  90                 return wait_event_interruptible(vb->done, WAITON_CONDITION);
  91         else
  92                 wait_event(vb->done, WAITON_CONDITION);
  93
  94         return 0;
  95 }
  96 EXPORT_SYMBOL_GPL(videobuf_waiton);
  97
  98 int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
  99                     struct v4l2_framebuffer *fbuf)
 100 {
 101         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
 102         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 103
 104         return CALL(q, iolock, q, vb, fbuf);
 105 }
 106 EXPORT_SYMBOL_GPL(videobuf_iolock);
 107
 108 void *videobuf_queue_to_vaddr(struct videobuf_queue *q,
 109                               struct videobuf_buffer *buf)
 110 {
 111         if (q->int_ops->vaddr)
 112                 return q->int_ops->vaddr(buf);
 113         return NULL;
 114 }
 115 EXPORT_SYMBOL_GPL(videobuf_queue_to_vaddr);
 116
 117 /* --------------------------------------------------------------------- */
 118
 119
 120 void videobuf_queue_core_init(struct videobuf_queue *q,
 121                          const struct videobuf_queue_ops *ops,
 122                          struct device *dev,
 123                          spinlock_t *irqlock,
 124                          enum v4l2_buf_type type,
 125                          enum v4l2_field field,
 126                          unsigned int msize,
 127                          void *priv,
 128                          struct videobuf_qtype_ops *int_ops)
 129 {
 130         BUG_ON(!q);
 131         memset(q, 0, sizeof(*q));
 132         q->irqlock   = irqlock;
 133         q->dev       = dev;
 134         q->type      = type;
 135         q->field     = field;
 136         q->msize     = msize;
 137         q->ops       = ops;
 138         q->priv_data = priv;
 139         q->int_ops   = int_ops;
 140
 141         /* All buffer operations are mandatory */
 142         BUG_ON(!q->ops->buf_setup);
 143         BUG_ON(!q->ops->buf_prepare);
 144         BUG_ON(!q->ops->buf_queue);
 145         BUG_ON(!q->ops->buf_release);
 146
 147         /* Lock is mandatory for queue_cancel to work */
 148         BUG_ON(!irqlock);
 149
 150         /* Having implementations for abstract methods are mandatory */
 151         BUG_ON(!q->int_ops);
 152
 153         mutex_init(&q->vb_lock);
 154         init_waitqueue_head(&q->wait);
 155         INIT_LIST_HEAD(&q->stream);
 156 }
 157 EXPORT_SYMBOL_GPL(videobuf_queue_core_init);
 158
 159 /* Locking: Only usage in bttv unsafe find way to remove */
 160 int videobuf_queue_is_busy(struct videobuf_queue *q)
 161 {
 162         int i;
 163
 164         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 165
 166         if (q->streaming) {
 167                 dprintk(1, "busy: streaming active\n");
 168                 return 1;
 169         }
 170         if (q->reading) {
 171                 dprintk(1, "busy: pending read #1\n");
 172                 return 1;
 173         }
 174         if (q->read_buf) {
 175                 dprintk(1, "busy: pending read #2\n");
 176                 return 1;
 177         }
 178         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 179                 if (NULL == q->bufs[i])
 180                         continue;
 181                 if (q->bufs[i]->map) {
 182                         dprintk(1, "busy: buffer #%d mapped\n", i);
 183                         return 1;
 184                 }
 185                 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
 186                         dprintk(1, "busy: buffer #%d queued\n", i);
 187                         return 1;
 188                 }
 189                 if (q->bufs[i]->state == VIDEOBUF_ACTIVE) {
 190                         dprintk(1, "busy: buffer #%d avtive\n", i);
 191                         return 1;
 192                 }
 193         }
 194         return 0;
 195 }
 196 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
 197
 198 /* Locking: Caller holds q->vb_lock */
 199 void videobuf_queue_cancel(struct videobuf_queue *q)
 200 {
 201         unsigned long flags = 0;
 202         int i;
 203
 204         q->streaming = 0;
 205         q->reading  = 0;
 206         wake_up_interruptible_sync(&q->wait);
 207
 208         /* remove queued buffers from list */
 209         spin_lock_irqsave(q->irqlock, flags);
 210         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 211                 if (NULL == q->bufs[i])
 212                         continue;
 213                 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
 214                         list_del(&q->bufs[i]->queue);
 215                         q->bufs[i]->state = VIDEOBUF_ERROR;
 216                         wake_up_all(&q->bufs[i]->done);
 217                 }
 218         }
 219         spin_unlock_irqrestore(q->irqlock, flags);
 220
 221         /* free all buffers + clear queue */
 222         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 223                 if (NULL == q->bufs[i])
 224                         continue;
 225                 q->ops->buf_release(q, q->bufs[i]);
 226         }
 227         INIT_LIST_HEAD(&q->stream);
 228 }
 229 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
 230
 231 /* --------------------------------------------------------------------- */
 232
 233 /* Locking: Caller holds q->vb_lock */
 234 enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
 235 {
 236         enum v4l2_field field = q->field;
 237
 238         BUG_ON(V4L2_FIELD_ANY == field);
 239
 240         if (V4L2_FIELD_ALTERNATE == field) {
 241                 if (V4L2_FIELD_TOP == q->last) {
 242                         field   = V4L2_FIELD_BOTTOM;
 243                         q->last = V4L2_FIELD_BOTTOM;
 244                 } else {
 245                         field   = V4L2_FIELD_TOP;
 246                         q->last = V4L2_FIELD_TOP;
 247                 }
 248         }
 249         return field;
 250 }
 251 EXPORT_SYMBOL_GPL(videobuf_next_field);
 252
 253 /* Locking: Caller holds q->vb_lock */
 254 static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
 255                             struct videobuf_buffer *vb, enum v4l2_buf_type type)
 256 {
 257         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
 258         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 259
 260         b->index    = vb->i;
 261         b->type     = type;
 262
 263         b->memory   = vb->memory;
 264         switch (b->memory) {
 265         case V4L2_MEMORY_MMAP:
 266                 b->m.offset  = vb->boff;
 267                 b->length    = vb->bsize;
 268                 break;
 269         case V4L2_MEMORY_USERPTR:
 270                 b->m.userptr = vb->baddr;
 271                 b->length    = vb->bsize;
 272                 break;
 273         case V4L2_MEMORY_OVERLAY:
 274                 b->m.offset  = vb->boff;
 275                 break;
 276         }
 277
 278         b->flags    = 0;
 279         if (vb->map)
 280                 b->flags |= V4L2_BUF_FLAG_MAPPED;
 281
 282         switch (vb->state) {
 283         case VIDEOBUF_PREPARED:
 284         case VIDEOBUF_QUEUED:
 285         case VIDEOBUF_ACTIVE:
 286                 b->flags |= V4L2_BUF_FLAG_QUEUED;
 287                 break;
 288         case VIDEOBUF_DONE:
 289         case VIDEOBUF_ERROR:
 290                 b->flags |= V4L2_BUF_FLAG_DONE;
 291                 break;
 292         case VIDEOBUF_NEEDS_INIT:
 293         case VIDEOBUF_IDLE:
 294                 /* nothing */
 295                 break;
 296         }
 297
 298         if (vb->input != UNSET) {
 299                 b->flags |= V4L2_BUF_FLAG_INPUT;
 300                 b->input  = vb->input;
 301         }
 302
 303         b->field     = vb->field;
 304         b->timestamp = vb->ts;
 305         b->bytesused = vb->size;
 306         b->sequence  = vb->field_count >> 1;
 307 }
 308
 309 /* Locking: Caller holds q->vb_lock */
 310 static int __videobuf_mmap_free(struct videobuf_queue *q)
 311 {
 312         int i;
 313
 314         if (!q)
 315                 return 0;
 316
 317         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 318
 319         for (i = 0; i < VIDEO_MAX_FRAME; i++)
 320                 if (q->bufs[i] && q->bufs[i]->map)
 321                         return -EBUSY;
 322
 323         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 324                 if (NULL == q->bufs[i])
 325                         continue;
 326                 q->ops->buf_release(q, q->bufs[i]);
 327                 kfree(q->bufs[i]);
 328                 q->bufs[i] = NULL;
 329         }
 330
 331         return 0;
 332 }
 333
 334 int videobuf_mmap_free(struct videobuf_queue *q)
 335 {
 336         int ret;
 337         mutex_lock(&q->vb_lock);
 338         ret = __videobuf_mmap_free(q);
 339         mutex_unlock(&q->vb_lock);
 340         return ret;
 341 }
 342 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
 343
 344 /* Locking: Caller holds q->vb_lock */
 345 int __videobuf_mmap_setup(struct videobuf_queue *q,
 346                         unsigned int bcount, unsigned int bsize,
 347                         enum v4l2_memory memory)
 348 {
 349         unsigned int i;
 350         int err;
 351
 352         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 353
 354         err = __videobuf_mmap_free(q);
 355         if (0 != err)
 356                 return err;
 357
 358         /* Allocate and initialize buffers */
 359         for (i = 0; i < bcount; i++) {
 360                 q->bufs[i] = videobuf_alloc(q);
 361
 362                 if (NULL == q->bufs[i])
 363                         break;
 364
 365                 q->bufs[i]->i      = i;
 366                 q->bufs[i]->input  = UNSET;
 367                 q->bufs[i]->memory = memory;
 368                 q->bufs[i]->bsize  = bsize;
 369                 switch (memory) {
 370                 case V4L2_MEMORY_MMAP:
 371                         q->bufs[i]->boff = PAGE_ALIGN(bsize) * i;
 372                         break;
 373                 case V4L2_MEMORY_USERPTR:
 374                 case V4L2_MEMORY_OVERLAY:
 375                         /* nothing */
 376                         break;
 377                 }
 378         }
 379
 380         if (!i)
 381                 return -ENOMEM;
 382
 383         dprintk(1, "mmap setup: %d buffers, %d bytes each\n", i, bsize);
 384
 385         return i;
 386 }
 387 EXPORT_SYMBOL_GPL(__videobuf_mmap_setup);
 388
 389 int videobuf_mmap_setup(struct videobuf_queue *q,
 390                         unsigned int bcount, unsigned int bsize,
 391                         enum v4l2_memory memory)
 392 {
 393         int ret;
 394         mutex_lock(&q->vb_lock);
 395         ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
 396         mutex_unlock(&q->vb_lock);
 397         return ret;
 398 }
 399 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
 400
 401 int videobuf_reqbufs(struct videobuf_queue *q,
 402                  struct v4l2_requestbuffers *req)
 403 {
 404         unsigned int size, count;
 405         int retval;
 406
 407         if (req->count < 1) {
 408                 dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
 409                 return -EINVAL;
 410         }
 411
 412         if (req->memory != V4L2_MEMORY_MMAP     &&
 413             req->memory != V4L2_MEMORY_USERPTR  &&
 414             req->memory != V4L2_MEMORY_OVERLAY) {
 415                 dprintk(1, "reqbufs: memory type invalid\n");
 416                 return -EINVAL;
 417         }
 418
 419         mutex_lock(&q->vb_lock);
 420         if (req->type != q->type) {
 421                 dprintk(1, "reqbufs: queue type invalid\n");
 422                 retval = -EINVAL;
 423                 goto done;
 424         }
 425
 426         if (q->streaming) {
 427                 dprintk(1, "reqbufs: streaming already exists\n");
 428                 retval = -EBUSY;
 429                 goto done;
 430         }
 431         if (!list_empty(&q->stream)) {
 432                 dprintk(1, "reqbufs: stream running\n");
 433                 retval = -EBUSY;
 434                 goto done;
 435         }
 436
 437         count = req->count;
 438         if (count > VIDEO_MAX_FRAME)
 439                 count = VIDEO_MAX_FRAME;
 440         size = 0;
 441         q->ops->buf_setup(q, &count, &size);
 442         dprintk(1, "reqbufs: bufs=%d, size=0x%x [%u pages total]\n",
 443                 count, size,
 444                 (unsigned int)((count * PAGE_ALIGN(size)) >> PAGE_SHIFT));
 445
 446         retval = __videobuf_mmap_setup(q, count, size, req->memory);
 447         if (retval < 0) {
 448                 dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
 449                 goto done;
 450         }
 451
 452         req->count = retval;
 453         retval = 0;
 454
 455  done:
 456         mutex_unlock(&q->vb_lock);
 457         return retval;
 458 }
 459 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
 460
 461 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 462 {
 463         int ret = -EINVAL;
 464
 465         mutex_lock(&q->vb_lock);
 466         if (unlikely(b->type != q->type)) {
 467                 dprintk(1, "querybuf: Wrong type.\n");
 468                 goto done;
 469         }
 470         if (unlikely(b->index >= VIDEO_MAX_FRAME)) {
 471                 dprintk(1, "querybuf: index out of range.\n");
 472                 goto done;
 473         }
 474         if (unlikely(NULL == q->bufs[b->index])) {
 475                 dprintk(1, "querybuf: buffer is null.\n");
 476                 goto done;
 477         }
 478
 479         videobuf_status(q, b, q->bufs[b->index], q->type);
 480
 481         ret = 0;
 482 done:
 483         mutex_unlock(&q->vb_lock);
 484         return ret;
 485 }
 486 EXPORT_SYMBOL_GPL(videobuf_querybuf);
 487
 488 int videobuf_qbuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 489 {
 490         struct videobuf_buffer *buf;
 491         enum v4l2_field field;
 492         unsigned long flags = 0;
 493         int retval;
 494
 495         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 496
 497         if (b->memory == V4L2_MEMORY_MMAP)
 498                 down_read(&current->mm->mmap_sem);
 499
 500         mutex_lock(&q->vb_lock);
 501         retval = -EBUSY;
 502         if (q->reading) {
 503                 dprintk(1, "qbuf: Reading running...\n");
 504                 goto done;
 505         }
 506         retval = -EINVAL;
 507         if (b->type != q->type) {
 508                 dprintk(1, "qbuf: Wrong type.\n");
 509                 goto done;
 510         }
 511         if (b->index >= VIDEO_MAX_FRAME) {
 512                 dprintk(1, "qbuf: index out of range.\n");
 513                 goto done;
 514         }
 515         buf = q->bufs[b->index];
 516         if (NULL == buf) {
 517                 dprintk(1, "qbuf: buffer is null.\n");
 518                 goto done;
 519         }
 520         MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
 521         if (buf->memory != b->memory) {
 522                 dprintk(1, "qbuf: memory type is wrong.\n");
 523                 goto done;
 524         }
 525         if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
 526                 dprintk(1, "qbuf: buffer is already queued or active.\n");
 527                 goto done;
 528         }
 529
 530         if (b->flags & V4L2_BUF_FLAG_INPUT) {
 531                 if (b->input >= q->inputs) {
 532                         dprintk(1, "qbuf: wrong input.\n");
 533                         goto done;
 534                 }
 535                 buf->input = b->input;
 536         } else {
 537                 buf->input = UNSET;
 538         }
 539
 540         switch (b->memory) {
 541         case V4L2_MEMORY_MMAP:
 542                 if (0 == buf->baddr) {
 543                         dprintk(1, "qbuf: mmap requested "
 544                                    "but buffer addr is zero!\n");
 545                         goto done;
 546                 }
 547                 break;
 548         case V4L2_MEMORY_USERPTR:
 549                 if (b->length < buf->bsize) {
 550                         dprintk(1, "qbuf: buffer length is not enough\n");
 551                         goto done;
 552                 }
 553                 if (VIDEOBUF_NEEDS_INIT != buf->state &&
 554                     buf->baddr != b->m.userptr)
 555                         q->ops->buf_release(q, buf);
 556                 buf->baddr = b->m.userptr;
 557                 break;
 558         case V4L2_MEMORY_OVERLAY:
 559                 buf->boff = b->m.offset;
 560                 break;
 561         default:
 562                 dprintk(1, "qbuf: wrong memory type\n");
 563                 goto done;
 564         }
 565
 566         dprintk(1, "qbuf: requesting next field\n");
 567         field = videobuf_next_field(q);
 568         retval = q->ops->buf_prepare(q, buf, field);
 569         if (0 != retval) {
 570                 dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
 571                 goto done;
 572         }
 573
 574         list_add_tail(&buf->stream, &q->stream);
 575         if (q->streaming) {
 576                 spin_lock_irqsave(q->irqlock, flags);
 577                 q->ops->buf_queue(q, buf);
 578                 spin_unlock_irqrestore(q->irqlock, flags);
 579         }
 580         dprintk(1, "qbuf: succeeded\n");
 581         retval = 0;
 582         wake_up_interruptible_sync(&q->wait);
 583
 584 done:
 585         mutex_unlock(&q->vb_lock);
 586
 587         if (b->memory == V4L2_MEMORY_MMAP)
 588                 up_read(&current->mm->mmap_sem);
 589
 590         return retval;
 591 }
 592 EXPORT_SYMBOL_GPL(videobuf_qbuf);
 593
 594 /* Locking: Caller holds q->vb_lock */
 595 static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
 596 {
 597         int retval;
 598
 599 checks:
 600         if (!q->streaming) {
 601                 dprintk(1, "next_buffer: Not streaming\n");
 602                 retval = -EINVAL;
 603                 goto done;
 604         }
 605
 606         if (list_empty(&q->stream)) {
 607                 if (noblock) {
 608                         retval = -EAGAIN;
 609                         dprintk(2, "next_buffer: no buffers to dequeue\n");
 610                         goto done;
 611                 } else {
 612                         dprintk(2, "next_buffer: waiting on buffer\n");
 613
 614                         /* Drop lock to avoid deadlock with qbuf */
 615                         mutex_unlock(&q->vb_lock);
 616
 617                         /* Checking list_empty and streaming is safe without
 618                          * locks because we goto checks to validate while
 619                          * holding locks before proceeding */
 620                         retval = wait_event_interruptible(q->wait,
 621                                 !list_empty(&q->stream) || !q->streaming);
 622                         mutex_lock(&q->vb_lock);
 623
 624                         if (retval)
 625                                 goto done;
 626
 627                         goto checks;
 628                 }
 629         }
 630
 631         retval = 0;
 632
 633 done:
 634         return retval;
 635 }
 636
 637 /* Locking: Caller holds q->vb_lock */
 638 static int stream_next_buffer(struct videobuf_queue *q,
 639                         struct videobuf_buffer **vb, int nonblocking)
 640 {
 641         int retval;
 642         struct videobuf_buffer *buf = NULL;
 643
 644         retval = stream_next_buffer_check_queue(q, nonblocking);
 645         if (retval)
 646                 goto done;
 647
 648         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 649         retval = videobuf_waiton(buf, nonblocking, 1);
 650         if (retval < 0)
 651                 goto done;
 652
 653         *vb = buf;
 654 done:
 655         return retval;
 656 }
 657
 658 int videobuf_dqbuf(struct videobuf_queue *q,
 659                    struct v4l2_buffer *b, int nonblocking)
 660 {
 661         struct videobuf_buffer *buf = NULL;
 662         int retval;
 663
 664         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 665
 666         mutex_lock(&q->vb_lock);
 667
 668         retval = stream_next_buffer(q, &buf, nonblocking);
 669         if (retval < 0) {
 670                 dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
 671                 goto done;
 672         }
 673
 674         switch (buf->state) {
 675         case VIDEOBUF_ERROR:
 676                 dprintk(1, "dqbuf: state is error\n");
 677                 retval = -EIO;
 678                 CALL(q, sync, q, buf);
 679                 buf->state = VIDEOBUF_IDLE;
 680                 break;
 681         case VIDEOBUF_DONE:
 682                 dprintk(1, "dqbuf: state is done\n");
 683                 CALL(q, sync, q, buf);
 684                 buf->state = VIDEOBUF_IDLE;
 685                 break;
 686         default:
 687                 dprintk(1, "dqbuf: state invalid\n");
 688                 retval = -EINVAL;
 689                 goto done;
 690         }
 691         list_del(&buf->stream);
 692         memset(b, 0, sizeof(*b));
 693         videobuf_status(q, b, buf, q->type);
 694 done:
 695         mutex_unlock(&q->vb_lock);
 696         return retval;
 697 }
 698 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
 699
 700 int videobuf_streamon(struct videobuf_queue *q)
 701 {
 702         struct videobuf_buffer *buf;
 703         unsigned long flags = 0;
 704         int retval;
 705
 706         mutex_lock(&q->vb_lock);
 707         retval = -EBUSY;
 708         if (q->reading)
 709                 goto done;
 710         retval = 0;
 711         if (q->streaming)
 712                 goto done;
 713         q->streaming = 1;
 714         spin_lock_irqsave(q->irqlock, flags);
 715         list_for_each_entry(buf, &q->stream, stream)
 716                 if (buf->state == VIDEOBUF_PREPARED)
 717                         q->ops->buf_queue(q, buf);
 718         spin_unlock_irqrestore(q->irqlock, flags);
 719
 720         wake_up_interruptible_sync(&q->wait);
 721 done:
 722         mutex_unlock(&q->vb_lock);
 723         return retval;
 724 }
 725 EXPORT_SYMBOL_GPL(videobuf_streamon);
 726
 727 /* Locking: Caller holds q->vb_lock */
 728 static int __videobuf_streamoff(struct videobuf_queue *q)
 729 {
 730         if (!q->streaming)
 731                 return -EINVAL;
 732
 733         videobuf_queue_cancel(q);
 734
 735         return 0;
 736 }
 737
 738 int videobuf_streamoff(struct videobuf_queue *q)
 739 {
 740         int retval;
 741
 742         mutex_lock(&q->vb_lock);
 743         retval = __videobuf_streamoff(q);
 744         mutex_unlock(&q->vb_lock);
 745
 746         return retval;
 747 }
 748 EXPORT_SYMBOL_GPL(videobuf_streamoff);
 749
 750 /* Locking: Caller holds q->vb_lock */
 751 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
 752                                       char __user *data,
 753                                       size_t count, loff_t *ppos)
 754 {
 755         enum v4l2_field field;
 756         unsigned long flags = 0;
 757         int retval;
 758
 759         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 760
 761         /* setup stuff */
 762         q->read_buf = videobuf_alloc(q);
 763         if (NULL == q->read_buf)
 764                 return -ENOMEM;
 765
 766         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 767         q->read_buf->baddr  = (unsigned long)data;
 768         q->read_buf->bsize  = count;
 769
 770         field = videobuf_next_field(q);
 771         retval = q->ops->buf_prepare(q, q->read_buf, field);
 772         if (0 != retval)
 773                 goto done;
 774
 775         /* start capture & wait */
 776         spin_lock_irqsave(q->irqlock, flags);
 777         q->ops->buf_queue(q, q->read_buf);
 778         spin_unlock_irqrestore(q->irqlock, flags);
 779         retval = videobuf_waiton(q->read_buf, 0, 0);
 780         if (0 == retval) {
 781                 CALL(q, sync, q, q->read_buf);
 782                 if (VIDEOBUF_ERROR == q->read_buf->state)
 783                         retval = -EIO;
 784                 else
 785                         retval = q->read_buf->size;
 786         }
 787
 788 done:
 789         /* cleanup */
 790         q->ops->buf_release(q, q->read_buf);
 791         kfree(q->read_buf);
 792         q->read_buf = NULL;
 793         return retval;
 794 }
 795
 796 ssize_t videobuf_read_one(struct videobuf_queue *q,
 797                           char __user *data, size_t count, loff_t *ppos,
 798                           int nonblocking)
 799 {
 800         enum v4l2_field field;
 801         unsigned long flags = 0;
 802         unsigned size = 0, nbufs = 1;
 803         int retval;
 804
 805         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 806
 807         mutex_lock(&q->vb_lock);
 808
 809         q->ops->buf_setup(q, &nbufs, &size);
 810
 811         if (NULL == q->read_buf  &&
 812             count >= size        &&
 813             !nonblocking) {
 814                 retval = videobuf_read_zerocopy(q, data, count, ppos);
 815                 if (retval >= 0  ||  retval == -EIO)
 816                         /* ok, all done */
 817                         goto done;
 818                 /* fallback to kernel bounce buffer on failures */
 819         }
 820
 821         if (NULL == q->read_buf) {
 822                 /* need to capture a new frame */
 823                 retval = -ENOMEM;
 824                 q->read_buf = videobuf_alloc(q);
 825
 826                 dprintk(1, "video alloc=0x%p\n", q->read_buf);
 827                 if (NULL == q->read_buf)
 828                         goto done;
 829                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 830                 q->read_buf->bsize = count; /* preferred size */
 831                 field = videobuf_next_field(q);
 832                 retval = q->ops->buf_prepare(q, q->read_buf, field);
 833
 834                 if (0 != retval) {
 835                         kfree(q->read_buf);
 836                         q->read_buf = NULL;
 837                         goto done;
 838                 }
 839
 840                 spin_lock_irqsave(q->irqlock, flags);
 841                 q->ops->buf_queue(q, q->read_buf);
 842                 spin_unlock_irqrestore(q->irqlock, flags);
 843
 844                 q->read_off = 0;
 845         }
 846
 847         /* wait until capture is done */
 848         retval = videobuf_waiton(q->read_buf, nonblocking, 1);
 849         if (0 != retval)
 850                 goto done;
 851
 852         CALL(q, sync, q, q->read_buf);
 853
 854         if (VIDEOBUF_ERROR == q->read_buf->state) {
 855                 /* catch I/O errors */
 856                 q->ops->buf_release(q, q->read_buf);
 857                 kfree(q->read_buf);
 858                 q->read_buf = NULL;
 859                 retval = -EIO;
 860                 goto done;
 861         }
 862
 863         /* Copy to userspace */
 864         retval = CALL(q, video_copy_to_user, q, data, count, nonblocking);
 865         if (retval < 0)
 866                 goto done;
 867
 868         q->read_off += retval;
 869         if (q->read_off == q->read_buf->size) {
 870                 /* all data copied, cleanup */
 871                 q->ops->buf_release(q, q->read_buf);
 872                 kfree(q->read_buf);
 873                 q->read_buf = NULL;
 874         }
 875
 876 done:
 877         mutex_unlock(&q->vb_lock);
 878         return retval;
 879 }
 880 EXPORT_SYMBOL_GPL(videobuf_read_one);
 881
 882 /* Locking: Caller holds q->vb_lock */
 883 static int __videobuf_read_start(struct videobuf_queue *q)
 884 {
 885         enum v4l2_field field;
 886         unsigned long flags = 0;
 887         unsigned int count = 0, size = 0;
 888         int err, i;
 889
 890         q->ops->buf_setup(q, &count, &size);
 891         if (count < 2)
 892                 count = 2;
 893         if (count > VIDEO_MAX_FRAME)
 894                 count = VIDEO_MAX_FRAME;
 895         size = PAGE_ALIGN(size);
 896
 897         err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
 898         if (err < 0)
 899                 return err;
 900
 901         count = err;
 902
 903         for (i = 0; i < count; i++) {
 904                 field = videobuf_next_field(q);
 905                 err = q->ops->buf_prepare(q, q->bufs[i], field);
 906                 if (err)
 907                         return err;
 908                 list_add_tail(&q->bufs[i]->stream, &q->stream);
 909         }
 910         spin_lock_irqsave(q->irqlock, flags);
 911         for (i = 0; i < count; i++)
 912                 q->ops->buf_queue(q, q->bufs[i]);
 913         spin_unlock_irqrestore(q->irqlock, flags);
 914         q->reading = 1;
 915         return 0;
 916 }
 917
 918 static void __videobuf_read_stop(struct videobuf_queue *q)
 919 {
 920         int i;
 921
 922         videobuf_queue_cancel(q);
 923         __videobuf_mmap_free(q);
 924         INIT_LIST_HEAD(&q->stream);
 925         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 926                 if (NULL == q->bufs[i])
 927                         continue;
 928                 kfree(q->bufs[i]);
 929                 q->bufs[i] = NULL;
 930         }
 931         q->read_buf = NULL;
 932 }
 933
 934 int videobuf_read_start(struct videobuf_queue *q)
 935 {
 936         int rc;
 937
 938         mutex_lock(&q->vb_lock);
 939         rc = __videobuf_read_start(q);
 940         mutex_unlock(&q->vb_lock);
 941
 942         return rc;
 943 }
 944 EXPORT_SYMBOL_GPL(videobuf_read_start);
 945
 946 void videobuf_read_stop(struct videobuf_queue *q)
 947 {
 948         mutex_lock(&q->vb_lock);
 949         __videobuf_read_stop(q);
 950         mutex_unlock(&q->vb_lock);
 951 }
 952 EXPORT_SYMBOL_GPL(videobuf_read_stop);
 953
 954 void videobuf_stop(struct videobuf_queue *q)
 955 {
 956         mutex_lock(&q->vb_lock);
 957
 958         if (q->streaming)
 959                 __videobuf_streamoff(q);
 960
 961         if (q->reading)
 962                 __videobuf_read_stop(q);
 963
 964         mutex_unlock(&q->vb_lock);
 965 }
 966 EXPORT_SYMBOL_GPL(videobuf_stop);
 967
 968 ssize_t videobuf_read_stream(struct videobuf_queue *q,
 969                              char __user *data, size_t count, loff_t *ppos,
 970                              int vbihack, int nonblocking)
 971 {
 972         int rc, retval;
 973         unsigned long flags = 0;
 974
 975         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 976
 977         dprintk(2, "%s\n", __func__);
 978         mutex_lock(&q->vb_lock);
 979         retval = -EBUSY;
 980         if (q->streaming)
 981                 goto done;
 982         if (!q->reading) {
 983                 retval = __videobuf_read_start(q);
 984                 if (retval < 0)
 985                         goto done;
 986         }
 987
 988         retval = 0;
 989         while (count > 0) {
 990                 /* get / wait for data */
 991                 if (NULL == q->read_buf) {
 992                         q->read_buf = list_entry(q->stream.next,
 993                                                  struct videobuf_buffer,
 994                                                  stream);
 995                         list_del(&q->read_buf->stream);
 996                         q->read_off = 0;
 997                 }
 998                 rc = videobuf_waiton(q->read_buf, nonblocking, 1);
 999                 if (rc < 0) {
1000                         if (0 == retval)
1001                                 retval = rc;
1002                         break;
1003                 }
1004
1005                 if (q->read_buf->state == VIDEOBUF_DONE) {
1006                         rc = CALL(q, copy_stream, q, data + retval, count,
1007                                         retval, vbihack, nonblocking);
1008                         if (rc < 0) {
1009                                 retval = rc;
1010                                 break;
1011                         }
1012                         retval      += rc;
1013                         count       -= rc;
1014                         q->read_off += rc;
1015                 } else {
1016                         /* some error */
1017                         q->read_off = q->read_buf->size;
1018                         if (0 == retval)
1019                                 retval = -EIO;
1020                 }
1021
1022                 /* requeue buffer when done with copying */
1023                 if (q->read_off == q->read_buf->size) {
1024                         list_add_tail(&q->read_buf->stream,
1025                                       &q->stream);
1026                         spin_lock_irqsave(q->irqlock, flags);
1027                         q->ops->buf_queue(q, q->read_buf);
1028                         spin_unlock_irqrestore(q->irqlock, flags);
1029                         q->read_buf = NULL;
1030                 }
1031                 if (retval < 0)
1032                         break;
1033         }
1034
1035 done:
1036         mutex_unlock(&q->vb_lock);
1037         return retval;
1038 }
1039 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1040
1041 unsigned int videobuf_poll_stream(struct file *file,
1042                                   struct videobuf_queue *q,
1043                                   poll_table *wait)
1044 {
1045         struct videobuf_buffer *buf = NULL;
1046         unsigned int rc = 0;
1047
1048         mutex_lock(&q->vb_lock);
1049         if (q->streaming) {
1050                 if (!list_empty(&q->stream))
1051                         buf = list_entry(q->stream.next,
1052                                          struct videobuf_buffer, stream);
1053         } else {
1054                 if (!q->reading)
1055                         __videobuf_read_start(q);
1056                 if (!q->reading) {
1057                         rc = POLLERR;
1058                 } else if (NULL == q->read_buf) {
1059                         q->read_buf = list_entry(q->stream.next,
1060                                                  struct videobuf_buffer,
1061                                                  stream);
1062                         list_del(&q->read_buf->stream);
1063                         q->read_off = 0;
1064                 }
1065                 buf = q->read_buf;
1066         }
1067         if (!buf)
1068                 rc = POLLERR;
1069
1070         if (0 == rc) {
1071                 poll_wait(file, &buf->done, wait);
1072                 if (buf->state == VIDEOBUF_DONE ||
1073                     buf->state == VIDEOBUF_ERROR)
1074                         rc = POLLIN|POLLRDNORM;
1075         }
1076         mutex_unlock(&q->vb_lock);
1077         return rc;
1078 }
1079 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1080
1081 int videobuf_mmap_mapper(struct videobuf_queue *q, struct vm_area_struct *vma)
1082 {
1083         int retval;
1084
1085         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1086
1087         mutex_lock(&q->vb_lock);
1088         retval = CALL(q, mmap_mapper, q, vma);
1089         mutex_unlock(&q->vb_lock);
1090
1091         return retval;
1092 }
1093 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
1094
1095 #ifdef CONFIG_VIDEO_V4L1_COMPAT
1096 int videobuf_cgmbuf(struct videobuf_queue *q,
1097                     struct video_mbuf *mbuf, int count)
1098 {
1099         struct v4l2_requestbuffers req;
1100         int rc, i;
1101
1102         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1103
1104         memset(&req, 0, sizeof(req));
1105         req.type   = q->type;
1106         req.count  = count;
1107         req.memory = V4L2_MEMORY_MMAP;
1108         rc = videobuf_reqbufs(q, &req);
1109         if (rc < 0)
1110                 return rc;
1111
1112         mbuf->frames = req.count;
1113         mbuf->size   = 0;
1114         for (i = 0; i < mbuf->frames; i++) {
1115                 mbuf->offsets[i]  = q->bufs[i]->boff;
1116                 mbuf->size       += PAGE_ALIGN(q->bufs[i]->bsize);
1117         }
1118
1119         return 0;
1120 }
1121 EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
1122 #endif
1123