drivers/media/v4l2-core/videobuf-core.c

   1 /*
   2  * generic helper functions for handling video4linux capture buffers
   3  *
   4  * (c) 2007 Mauro Carvalho Chehab, <[email protected]>
   5  *
   6  * Highly based on video-buf written originally by:
   7  * (c) 2001,02 Gerd Knorr <[email protected]>
   8  * (c) 2006 Mauro Carvalho Chehab, <[email protected]>
   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 <[email protected]>");
  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_vb(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_vb) {
  62                 printk(KERN_ERR "No specific ops defined!\n");
  63                 BUG();
  64         }
  65
  66         vb = q->int_ops->alloc_vb(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_vb);
  75
  76 static int is_state_active_or_queued(struct videobuf_queue *q, struct videobuf_buffer *vb)
  77 {
  78         unsigned long flags;
  79         bool rc;
  80
  81         spin_lock_irqsave(q->irqlock, flags);
  82         rc = vb->state != VIDEOBUF_ACTIVE && vb->state != VIDEOBUF_QUEUED;
  83         spin_unlock_irqrestore(q->irqlock, flags);
  84         return rc;
  85 };
  86
  87 int videobuf_waiton(struct videobuf_queue *q, struct videobuf_buffer *vb,
  88                 int non_blocking, int intr)
  89 {
  90         bool is_ext_locked;
  91         int ret = 0;
  92
  93         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
  94
  95         if (non_blocking) {
  96                 if (is_state_active_or_queued(q, vb))
  97                         return 0;
  98                 return -EAGAIN;
  99         }
 100
 101         is_ext_locked = q->ext_lock && mutex_is_locked(q->ext_lock);
 102
 103         /* Release vdev lock to prevent this wait from blocking outside access to
 104            the device. */
 105         if (is_ext_locked)
 106                 mutex_unlock(q->ext_lock);
 107         if (intr)
 108                 ret = wait_event_interruptible(vb->done, is_state_active_or_queued(q, vb));
 109         else
 110                 wait_event(vb->done, is_state_active_or_queued(q, vb));
 111         /* Relock */
 112         if (is_ext_locked)
 113                 mutex_lock(q->ext_lock);
 114
 115         return ret;
 116 }
 117 EXPORT_SYMBOL_GPL(videobuf_waiton);
 118
 119 int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
 120                     struct v4l2_framebuffer *fbuf)
 121 {
 122         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
 123         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 124
 125         return CALL(q, iolock, q, vb, fbuf);
 126 }
 127 EXPORT_SYMBOL_GPL(videobuf_iolock);
 128
 129 void *videobuf_queue_to_vaddr(struct videobuf_queue *q,
 130                               struct videobuf_buffer *buf)
 131 {
 132         if (q->int_ops->vaddr)
 133                 return q->int_ops->vaddr(buf);
 134         return NULL;
 135 }
 136 EXPORT_SYMBOL_GPL(videobuf_queue_to_vaddr);
 137
 138 /* --------------------------------------------------------------------- */
 139
 140
 141 void videobuf_queue_core_init(struct videobuf_queue *q,
 142                          const struct videobuf_queue_ops *ops,
 143                          struct device *dev,
 144                          spinlock_t *irqlock,
 145                          enum v4l2_buf_type type,
 146                          enum v4l2_field field,
 147                          unsigned int msize,
 148                          void *priv,
 149                          struct videobuf_qtype_ops *int_ops,
 150                          struct mutex *ext_lock)
 151 {
 152         BUG_ON(!q);
 153         memset(q, 0, sizeof(*q));
 154         q->irqlock   = irqlock;
 155         q->ext_lock  = ext_lock;
 156         q->dev       = dev;
 157         q->type      = type;
 158         q->field     = field;
 159         q->msize     = msize;
 160         q->ops       = ops;
 161         q->priv_data = priv;
 162         q->int_ops   = int_ops;
 163
 164         /* All buffer operations are mandatory */
 165         BUG_ON(!q->ops->buf_setup);
 166         BUG_ON(!q->ops->buf_prepare);
 167         BUG_ON(!q->ops->buf_queue);
 168         BUG_ON(!q->ops->buf_release);
 169
 170         /* Lock is mandatory for queue_cancel to work */
 171         BUG_ON(!irqlock);
 172
 173         /* Having implementations for abstract methods are mandatory */
 174         BUG_ON(!q->int_ops);
 175
 176         mutex_init(&q->vb_lock);
 177         init_waitqueue_head(&q->wait);
 178         INIT_LIST_HEAD(&q->stream);
 179 }
 180 EXPORT_SYMBOL_GPL(videobuf_queue_core_init);
 181
 182 /* Locking: Only usage in bttv unsafe find way to remove */
 183 int videobuf_queue_is_busy(struct videobuf_queue *q)
 184 {
 185         int i;
 186
 187         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 188
 189         if (q->streaming) {
 190                 dprintk(1, "busy: streaming active\n");
 191                 return 1;
 192         }
 193         if (q->reading) {
 194                 dprintk(1, "busy: pending read #1\n");
 195                 return 1;
 196         }
 197         if (q->read_buf) {
 198                 dprintk(1, "busy: pending read #2\n");
 199                 return 1;
 200         }
 201         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 202                 if (NULL == q->bufs[i])
 203                         continue;
 204                 if (q->bufs[i]->map) {
 205                         dprintk(1, "busy: buffer #%d mapped\n", i);
 206                         return 1;
 207                 }
 208                 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
 209                         dprintk(1, "busy: buffer #%d queued\n", i);
 210                         return 1;
 211                 }
 212                 if (q->bufs[i]->state == VIDEOBUF_ACTIVE) {
 213                         dprintk(1, "busy: buffer #%d avtive\n", i);
 214                         return 1;
 215                 }
 216         }
 217         return 0;
 218 }
 219 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
 220
 221 /**
 222  * __videobuf_free() - free all the buffers and their control structures
 223  *
 224  * This function can only be called if streaming/reading is off, i.e. no buffers
 225  * are under control of the driver.
 226  */
 227 /* Locking: Caller holds q->vb_lock */
 228 static int __videobuf_free(struct videobuf_queue *q)
 229 {
 230         int i;
 231
 232         dprintk(1, "%s\n", __func__);
 233         if (!q)
 234                 return 0;
 235
 236         if (q->streaming || q->reading) {
 237                 dprintk(1, "Cannot free buffers when streaming or reading\n");
 238                 return -EBUSY;
 239         }
 240
 241         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 242
 243         for (i = 0; i < VIDEO_MAX_FRAME; i++)
 244                 if (q->bufs[i] && q->bufs[i]->map) {
 245                         dprintk(1, "Cannot free mmapped buffers\n");
 246                         return -EBUSY;
 247                 }
 248
 249         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 250                 if (NULL == q->bufs[i])
 251                         continue;
 252                 q->ops->buf_release(q, q->bufs[i]);
 253                 kfree(q->bufs[i]);
 254                 q->bufs[i] = NULL;
 255         }
 256
 257         return 0;
 258 }
 259
 260 /* Locking: Caller holds q->vb_lock */
 261 void videobuf_queue_cancel(struct videobuf_queue *q)
 262 {
 263         unsigned long flags = 0;
 264         int i;
 265
 266         q->streaming = 0;
 267         q->reading  = 0;
 268         wake_up_interruptible_sync(&q->wait);
 269
 270         /* remove queued buffers from list */
 271         spin_lock_irqsave(q->irqlock, flags);
 272         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 273                 if (NULL == q->bufs[i])
 274                         continue;
 275                 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
 276                         list_del(&q->bufs[i]->queue);
 277                         q->bufs[i]->state = VIDEOBUF_ERROR;
 278                         wake_up_all(&q->bufs[i]->done);
 279                 }
 280         }
 281         spin_unlock_irqrestore(q->irqlock, flags);
 282
 283         /* free all buffers + clear queue */
 284         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 285                 if (NULL == q->bufs[i])
 286                         continue;
 287                 q->ops->buf_release(q, q->bufs[i]);
 288         }
 289         INIT_LIST_HEAD(&q->stream);
 290 }
 291 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
 292
 293 /* --------------------------------------------------------------------- */
 294
 295 /* Locking: Caller holds q->vb_lock */
 296 enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
 297 {
 298         enum v4l2_field field = q->field;
 299
 300         BUG_ON(V4L2_FIELD_ANY == field);
 301
 302         if (V4L2_FIELD_ALTERNATE == field) {
 303                 if (V4L2_FIELD_TOP == q->last) {
 304                         field   = V4L2_FIELD_BOTTOM;
 305                         q->last = V4L2_FIELD_BOTTOM;
 306                 } else {
 307                         field   = V4L2_FIELD_TOP;
 308                         q->last = V4L2_FIELD_TOP;
 309                 }
 310         }
 311         return field;
 312 }
 313 EXPORT_SYMBOL_GPL(videobuf_next_field);
 314
 315 /* Locking: Caller holds q->vb_lock */
 316 static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
 317                             struct videobuf_buffer *vb, enum v4l2_buf_type type)
 318 {
 319         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
 320         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 321
 322         b->index    = vb->i;
 323         b->type     = type;
 324
 325         b->memory   = vb->memory;
 326         switch (b->memory) {
 327         case V4L2_MEMORY_MMAP:
 328                 b->m.offset  = vb->boff;
 329                 b->length    = vb->bsize;
 330                 break;
 331         case V4L2_MEMORY_USERPTR:
 332                 b->m.userptr = vb->baddr;
 333                 b->length    = vb->bsize;
 334                 break;
 335         case V4L2_MEMORY_OVERLAY:
 336                 b->m.offset  = vb->boff;
 337                 break;
 338         case V4L2_MEMORY_DMABUF:
 339                 /* DMABUF is not handled in videobuf framework */
 340                 break;
 341         }
 342
 343         b->flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
 344         if (vb->map)
 345                 b->flags |= V4L2_BUF_FLAG_MAPPED;
 346
 347         switch (vb->state) {
 348         case VIDEOBUF_PREPARED:
 349         case VIDEOBUF_QUEUED:
 350         case VIDEOBUF_ACTIVE:
 351                 b->flags |= V4L2_BUF_FLAG_QUEUED;
 352                 break;
 353         case VIDEOBUF_ERROR:
 354                 b->flags |= V4L2_BUF_FLAG_ERROR;
 355                 /* fall through */
 356         case VIDEOBUF_DONE:
 357                 b->flags |= V4L2_BUF_FLAG_DONE;
 358                 break;
 359         case VIDEOBUF_NEEDS_INIT:
 360         case VIDEOBUF_IDLE:
 361                 /* nothing */
 362                 break;
 363         }
 364
 365         b->field     = vb->field;
 366         b->timestamp = vb->ts;
 367         b->bytesused = vb->size;
 368         b->sequence  = vb->field_count >> 1;
 369 }
 370
 371 int videobuf_mmap_free(struct videobuf_queue *q)
 372 {
 373         int ret;
 374         videobuf_queue_lock(q);
 375         ret = __videobuf_free(q);
 376         videobuf_queue_unlock(q);
 377         return ret;
 378 }
 379 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
 380
 381 /* Locking: Caller holds q->vb_lock */
 382 int __videobuf_mmap_setup(struct videobuf_queue *q,
 383                         unsigned int bcount, unsigned int bsize,
 384                         enum v4l2_memory memory)
 385 {
 386         unsigned int i;
 387         int err;
 388
 389         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 390
 391         err = __videobuf_free(q);
 392         if (0 != err)
 393                 return err;
 394
 395         /* Allocate and initialize buffers */
 396         for (i = 0; i < bcount; i++) {
 397                 q->bufs[i] = videobuf_alloc_vb(q);
 398
 399                 if (NULL == q->bufs[i])
 400                         break;
 401
 402                 q->bufs[i]->i      = i;
 403                 q->bufs[i]->memory = memory;
 404                 q->bufs[i]->bsize  = bsize;
 405                 switch (memory) {
 406                 case V4L2_MEMORY_MMAP:
 407                         q->bufs[i]->boff = PAGE_ALIGN(bsize) * i;
 408                         break;
 409                 case V4L2_MEMORY_USERPTR:
 410                 case V4L2_MEMORY_OVERLAY:
 411                 case V4L2_MEMORY_DMABUF:
 412                         /* nothing */
 413                         break;
 414                 }
 415         }
 416
 417         if (!i)
 418                 return -ENOMEM;
 419
 420         dprintk(1, "mmap setup: %d buffers, %d bytes each\n", i, bsize);
 421
 422         return i;
 423 }
 424 EXPORT_SYMBOL_GPL(__videobuf_mmap_setup);
 425
 426 int videobuf_mmap_setup(struct videobuf_queue *q,
 427                         unsigned int bcount, unsigned int bsize,
 428                         enum v4l2_memory memory)
 429 {
 430         int ret;
 431         videobuf_queue_lock(q);
 432         ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
 433         videobuf_queue_unlock(q);
 434         return ret;
 435 }
 436 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
 437
 438 int videobuf_reqbufs(struct videobuf_queue *q,
 439                  struct v4l2_requestbuffers *req)
 440 {
 441         unsigned int size, count;
 442         int retval;
 443
 444         if (req->count < 1) {
 445                 dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
 446                 return -EINVAL;
 447         }
 448
 449         if (req->memory != V4L2_MEMORY_MMAP     &&
 450             req->memory != V4L2_MEMORY_USERPTR  &&
 451             req->memory != V4L2_MEMORY_OVERLAY) {
 452                 dprintk(1, "reqbufs: memory type invalid\n");
 453                 return -EINVAL;
 454         }
 455
 456         videobuf_queue_lock(q);
 457         if (req->type != q->type) {
 458                 dprintk(1, "reqbufs: queue type invalid\n");
 459                 retval = -EINVAL;
 460                 goto done;
 461         }
 462
 463         if (q->streaming) {
 464                 dprintk(1, "reqbufs: streaming already exists\n");
 465                 retval = -EBUSY;
 466                 goto done;
 467         }
 468         if (!list_empty(&q->stream)) {
 469                 dprintk(1, "reqbufs: stream running\n");
 470                 retval = -EBUSY;
 471                 goto done;
 472         }
 473
 474         count = req->count;
 475         if (count > VIDEO_MAX_FRAME)
 476                 count = VIDEO_MAX_FRAME;
 477         size = 0;
 478         q->ops->buf_setup(q, &count, &size);
 479         dprintk(1, "reqbufs: bufs=%d, size=0x%x [%u pages total]\n",
 480                 count, size,
 481                 (unsigned int)((count * PAGE_ALIGN(size)) >> PAGE_SHIFT));
 482
 483         retval = __videobuf_mmap_setup(q, count, size, req->memory);
 484         if (retval < 0) {
 485                 dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
 486                 goto done;
 487         }
 488
 489         req->count = retval;
 490         retval = 0;
 491
 492  done:
 493         videobuf_queue_unlock(q);
 494         return retval;
 495 }
 496 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
 497
 498 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 499 {
 500         int ret = -EINVAL;
 501
 502         videobuf_queue_lock(q);
 503         if (unlikely(b->type != q->type)) {
 504                 dprintk(1, "querybuf: Wrong type.\n");
 505                 goto done;
 506         }
 507         if (unlikely(b->index >= VIDEO_MAX_FRAME)) {
 508                 dprintk(1, "querybuf: index out of range.\n");
 509                 goto done;
 510         }
 511         if (unlikely(NULL == q->bufs[b->index])) {
 512                 dprintk(1, "querybuf: buffer is null.\n");
 513                 goto done;
 514         }
 515
 516         videobuf_status(q, b, q->bufs[b->index], q->type);
 517
 518         ret = 0;
 519 done:
 520         videobuf_queue_unlock(q);
 521         return ret;
 522 }
 523 EXPORT_SYMBOL_GPL(videobuf_querybuf);
 524
 525 int videobuf_qbuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 526 {
 527         struct videobuf_buffer *buf;
 528         enum v4l2_field field;
 529         unsigned long flags = 0;
 530         int retval;
 531
 532         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 533
 534         if (b->memory == V4L2_MEMORY_MMAP)
 535                 down_read(&current->mm->mmap_sem);
 536
 537         videobuf_queue_lock(q);
 538         retval = -EBUSY;
 539         if (q->reading) {
 540                 dprintk(1, "qbuf: Reading running...\n");
 541                 goto done;
 542         }
 543         retval = -EINVAL;
 544         if (b->type != q->type) {
 545                 dprintk(1, "qbuf: Wrong type.\n");
 546                 goto done;
 547         }
 548         if (b->index >= VIDEO_MAX_FRAME) {
 549                 dprintk(1, "qbuf: index out of range.\n");
 550                 goto done;
 551         }
 552         buf = q->bufs[b->index];
 553         if (NULL == buf) {
 554                 dprintk(1, "qbuf: buffer is null.\n");
 555                 goto done;
 556         }
 557         MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
 558         if (buf->memory != b->memory) {
 559                 dprintk(1, "qbuf: memory type is wrong.\n");
 560                 goto done;
 561         }
 562         if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
 563                 dprintk(1, "qbuf: buffer is already queued or active.\n");
 564                 goto done;
 565         }
 566
 567         switch (b->memory) {
 568         case V4L2_MEMORY_MMAP:
 569                 if (0 == buf->baddr) {
 570                         dprintk(1, "qbuf: mmap requested "
 571                                    "but buffer addr is zero!\n");
 572                         goto done;
 573                 }
 574                 if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT
 575                     || q->type == V4L2_BUF_TYPE_VBI_OUTPUT
 576                     || q->type == V4L2_BUF_TYPE_SLICED_VBI_OUTPUT) {
 577                         buf->size = b->bytesused;
 578                         buf->field = b->field;
 579                         buf->ts = b->timestamp;
 580                 }
 581                 break;
 582         case V4L2_MEMORY_USERPTR:
 583                 if (b->length < buf->bsize) {
 584                         dprintk(1, "qbuf: buffer length is not enough\n");
 585                         goto done;
 586                 }
 587                 if (VIDEOBUF_NEEDS_INIT != buf->state &&
 588                     buf->baddr != b->m.userptr)
 589                         q->ops->buf_release(q, buf);
 590                 buf->baddr = b->m.userptr;
 591                 break;
 592         case V4L2_MEMORY_OVERLAY:
 593                 buf->boff = b->m.offset;
 594                 break;
 595         default:
 596                 dprintk(1, "qbuf: wrong memory type\n");
 597                 goto done;
 598         }
 599
 600         dprintk(1, "qbuf: requesting next field\n");
 601         field = videobuf_next_field(q);
 602         retval = q->ops->buf_prepare(q, buf, field);
 603         if (0 != retval) {
 604                 dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
 605                 goto done;
 606         }
 607
 608         list_add_tail(&buf->stream, &q->stream);
 609         if (q->streaming) {
 610                 spin_lock_irqsave(q->irqlock, flags);
 611                 q->ops->buf_queue(q, buf);
 612                 spin_unlock_irqrestore(q->irqlock, flags);
 613         }
 614         dprintk(1, "qbuf: succeeded\n");
 615         retval = 0;
 616         wake_up_interruptible_sync(&q->wait);
 617
 618 done:
 619         videobuf_queue_unlock(q);
 620
 621         if (b->memory == V4L2_MEMORY_MMAP)
 622                 up_read(&current->mm->mmap_sem);
 623
 624         return retval;
 625 }
 626 EXPORT_SYMBOL_GPL(videobuf_qbuf);
 627
 628 /* Locking: Caller holds q->vb_lock */
 629 static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
 630 {
 631         int retval;
 632
 633 checks:
 634         if (!q->streaming) {
 635                 dprintk(1, "next_buffer: Not streaming\n");
 636                 retval = -EINVAL;
 637                 goto done;
 638         }
 639
 640         if (list_empty(&q->stream)) {
 641                 if (noblock) {
 642                         retval = -EAGAIN;
 643                         dprintk(2, "next_buffer: no buffers to dequeue\n");
 644                         goto done;
 645                 } else {
 646                         dprintk(2, "next_buffer: waiting on buffer\n");
 647
 648                         /* Drop lock to avoid deadlock with qbuf */
 649                         videobuf_queue_unlock(q);
 650
 651                         /* Checking list_empty and streaming is safe without
 652                          * locks because we goto checks to validate while
 653                          * holding locks before proceeding */
 654                         retval = wait_event_interruptible(q->wait,
 655                                 !list_empty(&q->stream) || !q->streaming);
 656                         videobuf_queue_lock(q);
 657
 658                         if (retval)
 659                                 goto done;
 660
 661                         goto checks;
 662                 }
 663         }
 664
 665         retval = 0;
 666
 667 done:
 668         return retval;
 669 }
 670
 671 /* Locking: Caller holds q->vb_lock */
 672 static int stream_next_buffer(struct videobuf_queue *q,
 673                         struct videobuf_buffer **vb, int nonblocking)
 674 {
 675         int retval;
 676         struct videobuf_buffer *buf = NULL;
 677
 678         retval = stream_next_buffer_check_queue(q, nonblocking);
 679         if (retval)
 680                 goto done;
 681
 682         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 683         retval = videobuf_waiton(q, buf, nonblocking, 1);
 684         if (retval < 0)
 685                 goto done;
 686
 687         *vb = buf;
 688 done:
 689         return retval;
 690 }
 691
 692 int videobuf_dqbuf(struct videobuf_queue *q,
 693                    struct v4l2_buffer *b, int nonblocking)
 694 {
 695         struct videobuf_buffer *buf = NULL;
 696         int retval;
 697
 698         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 699
 700         memset(b, 0, sizeof(*b));
 701         videobuf_queue_lock(q);
 702
 703         retval = stream_next_buffer(q, &buf, nonblocking);
 704         if (retval < 0) {
 705                 dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
 706                 goto done;
 707         }
 708
 709         switch (buf->state) {
 710         case VIDEOBUF_ERROR:
 711                 dprintk(1, "dqbuf: state is error\n");
 712                 break;
 713         case VIDEOBUF_DONE:
 714                 dprintk(1, "dqbuf: state is done\n");
 715                 break;
 716         default:
 717                 dprintk(1, "dqbuf: state invalid\n");
 718                 retval = -EINVAL;
 719                 goto done;
 720         }
 721         CALL(q, sync, q, buf);
 722         videobuf_status(q, b, buf, q->type);
 723         list_del(&buf->stream);
 724         buf->state = VIDEOBUF_IDLE;
 725         b->flags &= ~V4L2_BUF_FLAG_DONE;
 726 done:
 727         videobuf_queue_unlock(q);
 728         return retval;
 729 }
 730 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
 731
 732 int videobuf_streamon(struct videobuf_queue *q)
 733 {
 734         struct videobuf_buffer *buf;
 735         unsigned long flags = 0;
 736         int retval;
 737
 738         videobuf_queue_lock(q);
 739         retval = -EBUSY;
 740         if (q->reading)
 741                 goto done;
 742         retval = 0;
 743         if (q->streaming)
 744                 goto done;
 745         q->streaming = 1;
 746         spin_lock_irqsave(q->irqlock, flags);
 747         list_for_each_entry(buf, &q->stream, stream)
 748                 if (buf->state == VIDEOBUF_PREPARED)
 749                         q->ops->buf_queue(q, buf);
 750         spin_unlock_irqrestore(q->irqlock, flags);
 751
 752         wake_up_interruptible_sync(&q->wait);
 753 done:
 754         videobuf_queue_unlock(q);
 755         return retval;
 756 }
 757 EXPORT_SYMBOL_GPL(videobuf_streamon);
 758
 759 /* Locking: Caller holds q->vb_lock */
 760 static int __videobuf_streamoff(struct videobuf_queue *q)
 761 {
 762         if (!q->streaming)
 763                 return -EINVAL;
 764
 765         videobuf_queue_cancel(q);
 766
 767         return 0;
 768 }
 769
 770 int videobuf_streamoff(struct videobuf_queue *q)
 771 {
 772         int retval;
 773
 774         videobuf_queue_lock(q);
 775         retval = __videobuf_streamoff(q);
 776         videobuf_queue_unlock(q);
 777
 778         return retval;
 779 }
 780 EXPORT_SYMBOL_GPL(videobuf_streamoff);
 781
 782 /* Locking: Caller holds q->vb_lock */
 783 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
 784                                       char __user *data,
 785                                       size_t count, loff_t *ppos)
 786 {
 787         enum v4l2_field field;
 788         unsigned long flags = 0;
 789         int retval;
 790
 791         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 792
 793         /* setup stuff */
 794         q->read_buf = videobuf_alloc_vb(q);
 795         if (NULL == q->read_buf)
 796                 return -ENOMEM;
 797
 798         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 799         q->read_buf->baddr  = (unsigned long)data;
 800         q->read_buf->bsize  = count;
 801
 802         field = videobuf_next_field(q);
 803         retval = q->ops->buf_prepare(q, q->read_buf, field);
 804         if (0 != retval)
 805                 goto done;
 806
 807         /* start capture & wait */
 808         spin_lock_irqsave(q->irqlock, flags);
 809         q->ops->buf_queue(q, q->read_buf);
 810         spin_unlock_irqrestore(q->irqlock, flags);
 811         retval = videobuf_waiton(q, q->read_buf, 0, 0);
 812         if (0 == retval) {
 813                 CALL(q, sync, q, q->read_buf);
 814                 if (VIDEOBUF_ERROR == q->read_buf->state)
 815                         retval = -EIO;
 816                 else
 817                         retval = q->read_buf->size;
 818         }
 819
 820 done:
 821         /* cleanup */
 822         q->ops->buf_release(q, q->read_buf);
 823         kfree(q->read_buf);
 824         q->read_buf = NULL;
 825         return retval;
 826 }
 827
 828 static int __videobuf_copy_to_user(struct videobuf_queue *q,
 829                                    struct videobuf_buffer *buf,
 830                                    char __user *data, size_t count,
 831                                    int nonblocking)
 832 {
 833         void *vaddr = CALL(q, vaddr, buf);
 834
 835         /* copy to userspace */
 836         if (count > buf->size - q->read_off)
 837                 count = buf->size - q->read_off;
 838
 839         if (copy_to_user(data, vaddr + q->read_off, count))
 840                 return -EFAULT;
 841
 842         return count;
 843 }
 844
 845 static int __videobuf_copy_stream(struct videobuf_queue *q,
 846                                   struct videobuf_buffer *buf,
 847                                   char __user *data, size_t count, size_t pos,
 848                                   int vbihack, int nonblocking)
 849 {
 850         unsigned int *fc = CALL(q, vaddr, buf);
 851
 852         if (vbihack) {
 853                 /* dirty, undocumented hack -- pass the frame counter
 854                         * within the last four bytes of each vbi data block.
 855                         * We need that one to maintain backward compatibility
 856                         * to all vbi decoding software out there ... */
 857                 fc += (buf->size >> 2) - 1;
 858                 *fc = buf->field_count >> 1;
 859                 dprintk(1, "vbihack: %d\n", *fc);
 860         }
 861
 862         /* copy stuff using the common method */
 863         count = __videobuf_copy_to_user(q, buf, data, count, nonblocking);
 864
 865         if ((count == -EFAULT) && (pos == 0))
 866                 return -EFAULT;
 867
 868         return count;
 869 }
 870
 871 ssize_t videobuf_read_one(struct videobuf_queue *q,
 872                           char __user *data, size_t count, loff_t *ppos,
 873                           int nonblocking)
 874 {
 875         enum v4l2_field field;
 876         unsigned long flags = 0;
 877         unsigned size = 0, nbufs = 1;
 878         int retval;
 879
 880         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 881
 882         videobuf_queue_lock(q);
 883
 884         q->ops->buf_setup(q, &nbufs, &size);
 885
 886         if (NULL == q->read_buf  &&
 887             count >= size        &&
 888             !nonblocking) {
 889                 retval = videobuf_read_zerocopy(q, data, count, ppos);
 890                 if (retval >= 0  ||  retval == -EIO)
 891                         /* ok, all done */
 892                         goto done;
 893                 /* fallback to kernel bounce buffer on failures */
 894         }
 895
 896         if (NULL == q->read_buf) {
 897                 /* need to capture a new frame */
 898                 retval = -ENOMEM;
 899                 q->read_buf = videobuf_alloc_vb(q);
 900
 901                 dprintk(1, "video alloc=0x%p\n", q->read_buf);
 902                 if (NULL == q->read_buf)
 903                         goto done;
 904                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 905                 q->read_buf->bsize = count; /* preferred size */
 906                 field = videobuf_next_field(q);
 907                 retval = q->ops->buf_prepare(q, q->read_buf, field);
 908
 909                 if (0 != retval) {
 910                         kfree(q->read_buf);
 911                         q->read_buf = NULL;
 912                         goto done;
 913                 }
 914
 915                 spin_lock_irqsave(q->irqlock, flags);
 916                 q->ops->buf_queue(q, q->read_buf);
 917                 spin_unlock_irqrestore(q->irqlock, flags);
 918
 919                 q->read_off = 0;
 920         }
 921
 922         /* wait until capture is done */
 923         retval = videobuf_waiton(q, q->read_buf, nonblocking, 1);
 924         if (0 != retval)
 925                 goto done;
 926
 927         CALL(q, sync, q, q->read_buf);
 928
 929         if (VIDEOBUF_ERROR == q->read_buf->state) {
 930                 /* catch I/O errors */
 931                 q->ops->buf_release(q, q->read_buf);
 932                 kfree(q->read_buf);
 933                 q->read_buf = NULL;
 934                 retval = -EIO;
 935                 goto done;
 936         }
 937
 938         /* Copy to userspace */
 939         retval = __videobuf_copy_to_user(q, q->read_buf, data, count, nonblocking);
 940         if (retval < 0)
 941                 goto done;
 942
 943         q->read_off += retval;
 944         if (q->read_off == q->read_buf->size) {
 945                 /* all data copied, cleanup */
 946                 q->ops->buf_release(q, q->read_buf);
 947                 kfree(q->read_buf);
 948                 q->read_buf = NULL;
 949         }
 950
 951 done:
 952         videobuf_queue_unlock(q);
 953         return retval;
 954 }
 955 EXPORT_SYMBOL_GPL(videobuf_read_one);
 956
 957 /* Locking: Caller holds q->vb_lock */
 958 static int __videobuf_read_start(struct videobuf_queue *q)
 959 {
 960         enum v4l2_field field;
 961         unsigned long flags = 0;
 962         unsigned int count = 0, size = 0;
 963         int err, i;
 964
 965         q->ops->buf_setup(q, &count, &size);
 966         if (count < 2)
 967                 count = 2;
 968         if (count > VIDEO_MAX_FRAME)
 969                 count = VIDEO_MAX_FRAME;
 970         size = PAGE_ALIGN(size);
 971
 972         err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
 973         if (err < 0)
 974                 return err;
 975
 976         count = err;
 977
 978         for (i = 0; i < count; i++) {
 979                 field = videobuf_next_field(q);
 980                 err = q->ops->buf_prepare(q, q->bufs[i], field);
 981                 if (err)
 982                         return err;
 983                 list_add_tail(&q->bufs[i]->stream, &q->stream);
 984         }
 985         spin_lock_irqsave(q->irqlock, flags);
 986         for (i = 0; i < count; i++)
 987                 q->ops->buf_queue(q, q->bufs[i]);
 988         spin_unlock_irqrestore(q->irqlock, flags);
 989         q->reading = 1;
 990         return 0;
 991 }
 992
 993 static void __videobuf_read_stop(struct videobuf_queue *q)
 994 {
 995         int i;
 996
 997         videobuf_queue_cancel(q);
 998         __videobuf_free(q);
 999         INIT_LIST_HEAD(&q->stream);
1000         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1001                 if (NULL == q->bufs[i])
1002                         continue;
1003                 kfree(q->bufs[i]);
1004                 q->bufs[i] = NULL;
1005         }
1006         q->read_buf = NULL;
1007 }
1008
1009 int videobuf_read_start(struct videobuf_queue *q)
1010 {
1011         int rc;
1012
1013         videobuf_queue_lock(q);
1014         rc = __videobuf_read_start(q);
1015         videobuf_queue_unlock(q);
1016
1017         return rc;
1018 }
1019 EXPORT_SYMBOL_GPL(videobuf_read_start);
1020
1021 void videobuf_read_stop(struct videobuf_queue *q)
1022 {
1023         videobuf_queue_lock(q);
1024         __videobuf_read_stop(q);
1025         videobuf_queue_unlock(q);
1026 }
1027 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1028
1029 void videobuf_stop(struct videobuf_queue *q)
1030 {
1031         videobuf_queue_lock(q);
1032
1033         if (q->streaming)
1034                 __videobuf_streamoff(q);
1035
1036         if (q->reading)
1037                 __videobuf_read_stop(q);
1038
1039         videobuf_queue_unlock(q);
1040 }
1041 EXPORT_SYMBOL_GPL(videobuf_stop);
1042
1043 ssize_t videobuf_read_stream(struct videobuf_queue *q,
1044                              char __user *data, size_t count, loff_t *ppos,
1045                              int vbihack, int nonblocking)
1046 {
1047         int rc, retval;
1048         unsigned long flags = 0;
1049
1050         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1051
1052         dprintk(2, "%s\n", __func__);
1053         videobuf_queue_lock(q);
1054         retval = -EBUSY;
1055         if (q->streaming)
1056                 goto done;
1057         if (!q->reading) {
1058                 retval = __videobuf_read_start(q);
1059                 if (retval < 0)
1060                         goto done;
1061         }
1062
1063         retval = 0;
1064         while (count > 0) {
1065                 /* get / wait for data */
1066                 if (NULL == q->read_buf) {
1067                         q->read_buf = list_entry(q->stream.next,
1068                                                  struct videobuf_buffer,
1069                                                  stream);
1070                         list_del(&q->read_buf->stream);
1071                         q->read_off = 0;
1072                 }
1073                 rc = videobuf_waiton(q, q->read_buf, nonblocking, 1);
1074                 if (rc < 0) {
1075                         if (0 == retval)
1076                                 retval = rc;
1077                         break;
1078                 }
1079
1080                 if (q->read_buf->state == VIDEOBUF_DONE) {
1081                         rc = __videobuf_copy_stream(q, q->read_buf, data + retval, count,
1082                                         retval, vbihack, nonblocking);
1083                         if (rc < 0) {
1084                                 retval = rc;
1085                                 break;
1086                         }
1087                         retval      += rc;
1088                         count       -= rc;
1089                         q->read_off += rc;
1090                 } else {
1091                         /* some error */
1092                         q->read_off = q->read_buf->size;
1093                         if (0 == retval)
1094                                 retval = -EIO;
1095                 }
1096
1097                 /* requeue buffer when done with copying */
1098                 if (q->read_off == q->read_buf->size) {
1099                         list_add_tail(&q->read_buf->stream,
1100                                       &q->stream);
1101                         spin_lock_irqsave(q->irqlock, flags);
1102                         q->ops->buf_queue(q, q->read_buf);
1103                         spin_unlock_irqrestore(q->irqlock, flags);
1104                         q->read_buf = NULL;
1105                 }
1106                 if (retval < 0)
1107                         break;
1108         }
1109
1110 done:
1111         videobuf_queue_unlock(q);
1112         return retval;
1113 }
1114 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1115
1116 unsigned int videobuf_poll_stream(struct file *file,
1117                                   struct videobuf_queue *q,
1118                                   poll_table *wait)
1119 {
1120         unsigned long req_events = poll_requested_events(wait);
1121         struct videobuf_buffer *buf = NULL;
1122         unsigned int rc = 0;
1123
1124         videobuf_queue_lock(q);
1125         if (q->streaming) {
1126                 if (!list_empty(&q->stream))
1127                         buf = list_entry(q->stream.next,
1128                                          struct videobuf_buffer, stream);
1129         } else if (req_events & (POLLIN | POLLRDNORM)) {
1130                 if (!q->reading)
1131                         __videobuf_read_start(q);
1132                 if (!q->reading) {
1133                         rc = POLLERR;
1134                 } else if (NULL == q->read_buf) {
1135                         q->read_buf = list_entry(q->stream.next,
1136                                                  struct videobuf_buffer,
1137                                                  stream);
1138                         list_del(&q->read_buf->stream);
1139                         q->read_off = 0;
1140                 }
1141                 buf = q->read_buf;
1142         }
1143         if (!buf)
1144                 rc = POLLERR;
1145
1146         if (0 == rc) {
1147                 poll_wait(file, &buf->done, wait);
1148                 if (buf->state == VIDEOBUF_DONE ||
1149                     buf->state == VIDEOBUF_ERROR) {
1150                         switch (q->type) {
1151                         case V4L2_BUF_TYPE_VIDEO_OUTPUT:
1152                         case V4L2_BUF_TYPE_VBI_OUTPUT:
1153                         case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
1154                                 rc = POLLOUT | POLLWRNORM;
1155                                 break;
1156                         default:
1157                                 rc = POLLIN | POLLRDNORM;
1158                                 break;
1159                         }
1160                 }
1161         }
1162         videobuf_queue_unlock(q);
1163         return rc;
1164 }
1165 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1166
1167 int videobuf_mmap_mapper(struct videobuf_queue *q, struct vm_area_struct *vma)
1168 {
1169         int rc = -EINVAL;
1170         int i;
1171
1172         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1173
1174         if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED)) {
1175                 dprintk(1, "mmap appl bug: PROT_WRITE and MAP_SHARED are required\n");
1176                 return -EINVAL;
1177         }
1178
1179         videobuf_queue_lock(q);
1180         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1181                 struct videobuf_buffer *buf = q->bufs[i];
1182
1183                 if (buf && buf->memory == V4L2_MEMORY_MMAP &&
1184                                 buf->boff == (vma->vm_pgoff << PAGE_SHIFT)) {
1185                         rc = CALL(q, mmap_mapper, q, buf, vma);
1186                         break;
1187                 }
1188         }
1189         videobuf_queue_unlock(q);
1190
1191         return rc;
1192 }
1193 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);