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_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         }
 339
 340         b->flags    = 0;
 341         if (vb->map)
 342                 b->flags |= V4L2_BUF_FLAG_MAPPED;
 343
 344         switch (vb->state) {
 345         case VIDEOBUF_PREPARED:
 346         case VIDEOBUF_QUEUED:
 347         case VIDEOBUF_ACTIVE:
 348                 b->flags |= V4L2_BUF_FLAG_QUEUED;
 349                 break;
 350         case VIDEOBUF_ERROR:
 351                 b->flags |= V4L2_BUF_FLAG_ERROR;
 352                 /* fall through */
 353         case VIDEOBUF_DONE:
 354                 b->flags |= V4L2_BUF_FLAG_DONE;
 355                 break;
 356         case VIDEOBUF_NEEDS_INIT:
 357         case VIDEOBUF_IDLE:
 358                 /* nothing */
 359                 break;
 360         }
 361
 362         b->field     = vb->field;
 363         b->timestamp = vb->ts;
 364         b->bytesused = vb->size;
 365         b->sequence  = vb->field_count >> 1;
 366 }
 367
 368 int videobuf_mmap_free(struct videobuf_queue *q)
 369 {
 370         int ret;
 371         videobuf_queue_lock(q);
 372         ret = __videobuf_free(q);
 373         videobuf_queue_unlock(q);
 374         return ret;
 375 }
 376 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
 377
 378 /* Locking: Caller holds q->vb_lock */
 379 int __videobuf_mmap_setup(struct videobuf_queue *q,
 380                         unsigned int bcount, unsigned int bsize,
 381                         enum v4l2_memory memory)
 382 {
 383         unsigned int i;
 384         int err;
 385
 386         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 387
 388         err = __videobuf_free(q);
 389         if (0 != err)
 390                 return err;
 391
 392         /* Allocate and initialize buffers */
 393         for (i = 0; i < bcount; i++) {
 394                 q->bufs[i] = videobuf_alloc_vb(q);
 395
 396                 if (NULL == q->bufs[i])
 397                         break;
 398
 399                 q->bufs[i]->i      = i;
 400                 q->bufs[i]->memory = memory;
 401                 q->bufs[i]->bsize  = bsize;
 402                 switch (memory) {
 403                 case V4L2_MEMORY_MMAP:
 404                         q->bufs[i]->boff = PAGE_ALIGN(bsize) * i;
 405                         break;
 406                 case V4L2_MEMORY_USERPTR:
 407                 case V4L2_MEMORY_OVERLAY:
 408                         /* nothing */
 409                         break;
 410                 }
 411         }
 412
 413         if (!i)
 414                 return -ENOMEM;
 415
 416         dprintk(1, "mmap setup: %d buffers, %d bytes each\n", i, bsize);
 417
 418         return i;
 419 }
 420 EXPORT_SYMBOL_GPL(__videobuf_mmap_setup);
 421
 422 int videobuf_mmap_setup(struct videobuf_queue *q,
 423                         unsigned int bcount, unsigned int bsize,
 424                         enum v4l2_memory memory)
 425 {
 426         int ret;
 427         videobuf_queue_lock(q);
 428         ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
 429         videobuf_queue_unlock(q);
 430         return ret;
 431 }
 432 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
 433
 434 int videobuf_reqbufs(struct videobuf_queue *q,
 435                  struct v4l2_requestbuffers *req)
 436 {
 437         unsigned int size, count;
 438         int retval;
 439
 440         if (req->count < 1) {
 441                 dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
 442                 return -EINVAL;
 443         }
 444
 445         if (req->memory != V4L2_MEMORY_MMAP     &&
 446             req->memory != V4L2_MEMORY_USERPTR  &&
 447             req->memory != V4L2_MEMORY_OVERLAY) {
 448                 dprintk(1, "reqbufs: memory type invalid\n");
 449                 return -EINVAL;
 450         }
 451
 452         videobuf_queue_lock(q);
 453         if (req->type != q->type) {
 454                 dprintk(1, "reqbufs: queue type invalid\n");
 455                 retval = -EINVAL;
 456                 goto done;
 457         }
 458
 459         if (q->streaming) {
 460                 dprintk(1, "reqbufs: streaming already exists\n");
 461                 retval = -EBUSY;
 462                 goto done;
 463         }
 464         if (!list_empty(&q->stream)) {
 465                 dprintk(1, "reqbufs: stream running\n");
 466                 retval = -EBUSY;
 467                 goto done;
 468         }
 469
 470         count = req->count;
 471         if (count > VIDEO_MAX_FRAME)
 472                 count = VIDEO_MAX_FRAME;
 473         size = 0;
 474         q->ops->buf_setup(q, &count, &size);
 475         dprintk(1, "reqbufs: bufs=%d, size=0x%x [%u pages total]\n",
 476                 count, size,
 477                 (unsigned int)((count * PAGE_ALIGN(size)) >> PAGE_SHIFT));
 478
 479         retval = __videobuf_mmap_setup(q, count, size, req->memory);
 480         if (retval < 0) {
 481                 dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
 482                 goto done;
 483         }
 484
 485         req->count = retval;
 486         retval = 0;
 487
 488  done:
 489         videobuf_queue_unlock(q);
 490         return retval;
 491 }
 492 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
 493
 494 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 495 {
 496         int ret = -EINVAL;
 497
 498         videobuf_queue_lock(q);
 499         if (unlikely(b->type != q->type)) {
 500                 dprintk(1, "querybuf: Wrong type.\n");
 501                 goto done;
 502         }
 503         if (unlikely(b->index >= VIDEO_MAX_FRAME)) {
 504                 dprintk(1, "querybuf: index out of range.\n");
 505                 goto done;
 506         }
 507         if (unlikely(NULL == q->bufs[b->index])) {
 508                 dprintk(1, "querybuf: buffer is null.\n");
 509                 goto done;
 510         }
 511
 512         videobuf_status(q, b, q->bufs[b->index], q->type);
 513
 514         ret = 0;
 515 done:
 516         videobuf_queue_unlock(q);
 517         return ret;
 518 }
 519 EXPORT_SYMBOL_GPL(videobuf_querybuf);
 520
 521 int videobuf_qbuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 522 {
 523         struct videobuf_buffer *buf;
 524         enum v4l2_field field;
 525         unsigned long flags = 0;
 526         int retval;
 527
 528         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 529
 530         if (b->memory == V4L2_MEMORY_MMAP)
 531                 down_read(&current->mm->mmap_sem);
 532
 533         videobuf_queue_lock(q);
 534         retval = -EBUSY;
 535         if (q->reading) {
 536                 dprintk(1, "qbuf: Reading running...\n");
 537                 goto done;
 538         }
 539         retval = -EINVAL;
 540         if (b->type != q->type) {
 541                 dprintk(1, "qbuf: Wrong type.\n");
 542                 goto done;
 543         }
 544         if (b->index >= VIDEO_MAX_FRAME) {
 545                 dprintk(1, "qbuf: index out of range.\n");
 546                 goto done;
 547         }
 548         buf = q->bufs[b->index];
 549         if (NULL == buf) {
 550                 dprintk(1, "qbuf: buffer is null.\n");
 551                 goto done;
 552         }
 553         MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
 554         if (buf->memory != b->memory) {
 555                 dprintk(1, "qbuf: memory type is wrong.\n");
 556                 goto done;
 557         }
 558         if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
 559                 dprintk(1, "qbuf: buffer is already queued or active.\n");
 560                 goto done;
 561         }
 562
 563         switch (b->memory) {
 564         case V4L2_MEMORY_MMAP:
 565                 if (0 == buf->baddr) {
 566                         dprintk(1, "qbuf: mmap requested "
 567                                    "but buffer addr is zero!\n");
 568                         goto done;
 569                 }
 570                 if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT
 571                     || q->type == V4L2_BUF_TYPE_VBI_OUTPUT
 572                     || q->type == V4L2_BUF_TYPE_SLICED_VBI_OUTPUT) {
 573                         buf->size = b->bytesused;
 574                         buf->field = b->field;
 575                         buf->ts = b->timestamp;
 576                 }
 577                 break;
 578         case V4L2_MEMORY_USERPTR:
 579                 if (b->length < buf->bsize) {
 580                         dprintk(1, "qbuf: buffer length is not enough\n");
 581                         goto done;
 582                 }
 583                 if (VIDEOBUF_NEEDS_INIT != buf->state &&
 584                     buf->baddr != b->m.userptr)
 585                         q->ops->buf_release(q, buf);
 586                 buf->baddr = b->m.userptr;
 587                 break;
 588         case V4L2_MEMORY_OVERLAY:
 589                 buf->boff = b->m.offset;
 590                 break;
 591         default:
 592                 dprintk(1, "qbuf: wrong memory type\n");
 593                 goto done;
 594         }
 595
 596         dprintk(1, "qbuf: requesting next field\n");
 597         field = videobuf_next_field(q);
 598         retval = q->ops->buf_prepare(q, buf, field);
 599         if (0 != retval) {
 600                 dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
 601                 goto done;
 602         }
 603
 604         list_add_tail(&buf->stream, &q->stream);
 605         if (q->streaming) {
 606                 spin_lock_irqsave(q->irqlock, flags);
 607                 q->ops->buf_queue(q, buf);
 608                 spin_unlock_irqrestore(q->irqlock, flags);
 609         }
 610         dprintk(1, "qbuf: succeeded\n");
 611         retval = 0;
 612         wake_up_interruptible_sync(&q->wait);
 613
 614 done:
 615         videobuf_queue_unlock(q);
 616
 617         if (b->memory == V4L2_MEMORY_MMAP)
 618                 up_read(&current->mm->mmap_sem);
 619
 620         return retval;
 621 }
 622 EXPORT_SYMBOL_GPL(videobuf_qbuf);
 623
 624 /* Locking: Caller holds q->vb_lock */
 625 static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
 626 {
 627         int retval;
 628
 629 checks:
 630         if (!q->streaming) {
 631                 dprintk(1, "next_buffer: Not streaming\n");
 632                 retval = -EINVAL;
 633                 goto done;
 634         }
 635
 636         if (list_empty(&q->stream)) {
 637                 if (noblock) {
 638                         retval = -EAGAIN;
 639                         dprintk(2, "next_buffer: no buffers to dequeue\n");
 640                         goto done;
 641                 } else {
 642                         dprintk(2, "next_buffer: waiting on buffer\n");
 643
 644                         /* Drop lock to avoid deadlock with qbuf */
 645                         videobuf_queue_unlock(q);
 646
 647                         /* Checking list_empty and streaming is safe without
 648                          * locks because we goto checks to validate while
 649                          * holding locks before proceeding */
 650                         retval = wait_event_interruptible(q->wait,
 651                                 !list_empty(&q->stream) || !q->streaming);
 652                         videobuf_queue_lock(q);
 653
 654                         if (retval)
 655                                 goto done;
 656
 657                         goto checks;
 658                 }
 659         }
 660
 661         retval = 0;
 662
 663 done:
 664         return retval;
 665 }
 666
 667 /* Locking: Caller holds q->vb_lock */
 668 static int stream_next_buffer(struct videobuf_queue *q,
 669                         struct videobuf_buffer **vb, int nonblocking)
 670 {
 671         int retval;
 672         struct videobuf_buffer *buf = NULL;
 673
 674         retval = stream_next_buffer_check_queue(q, nonblocking);
 675         if (retval)
 676                 goto done;
 677
 678         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 679         retval = videobuf_waiton(q, buf, nonblocking, 1);
 680         if (retval < 0)
 681                 goto done;
 682
 683         *vb = buf;
 684 done:
 685         return retval;
 686 }
 687
 688 int videobuf_dqbuf(struct videobuf_queue *q,
 689                    struct v4l2_buffer *b, int nonblocking)
 690 {
 691         struct videobuf_buffer *buf = NULL;
 692         int retval;
 693
 694         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 695
 696         memset(b, 0, sizeof(*b));
 697         videobuf_queue_lock(q);
 698
 699         retval = stream_next_buffer(q, &buf, nonblocking);
 700         if (retval < 0) {
 701                 dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
 702                 goto done;
 703         }
 704
 705         switch (buf->state) {
 706         case VIDEOBUF_ERROR:
 707                 dprintk(1, "dqbuf: state is error\n");
 708                 break;
 709         case VIDEOBUF_DONE:
 710                 dprintk(1, "dqbuf: state is done\n");
 711                 break;
 712         default:
 713                 dprintk(1, "dqbuf: state invalid\n");
 714                 retval = -EINVAL;
 715                 goto done;
 716         }
 717         CALL(q, sync, q, buf);
 718         videobuf_status(q, b, buf, q->type);
 719         list_del(&buf->stream);
 720         buf->state = VIDEOBUF_IDLE;
 721         b->flags &= ~V4L2_BUF_FLAG_DONE;
 722 done:
 723         videobuf_queue_unlock(q);
 724         return retval;
 725 }
 726 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
 727
 728 int videobuf_streamon(struct videobuf_queue *q)
 729 {
 730         struct videobuf_buffer *buf;
 731         unsigned long flags = 0;
 732         int retval;
 733
 734         videobuf_queue_lock(q);
 735         retval = -EBUSY;
 736         if (q->reading)
 737                 goto done;
 738         retval = 0;
 739         if (q->streaming)
 740                 goto done;
 741         q->streaming = 1;
 742         spin_lock_irqsave(q->irqlock, flags);
 743         list_for_each_entry(buf, &q->stream, stream)
 744                 if (buf->state == VIDEOBUF_PREPARED)
 745                         q->ops->buf_queue(q, buf);
 746         spin_unlock_irqrestore(q->irqlock, flags);
 747
 748         wake_up_interruptible_sync(&q->wait);
 749 done:
 750         videobuf_queue_unlock(q);
 751         return retval;
 752 }
 753 EXPORT_SYMBOL_GPL(videobuf_streamon);
 754
 755 /* Locking: Caller holds q->vb_lock */
 756 static int __videobuf_streamoff(struct videobuf_queue *q)
 757 {
 758         if (!q->streaming)
 759                 return -EINVAL;
 760
 761         videobuf_queue_cancel(q);
 762
 763         return 0;
 764 }
 765
 766 int videobuf_streamoff(struct videobuf_queue *q)
 767 {
 768         int retval;
 769
 770         videobuf_queue_lock(q);
 771         retval = __videobuf_streamoff(q);
 772         videobuf_queue_unlock(q);
 773
 774         return retval;
 775 }
 776 EXPORT_SYMBOL_GPL(videobuf_streamoff);
 777
 778 /* Locking: Caller holds q->vb_lock */
 779 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
 780                                       char __user *data,
 781                                       size_t count, loff_t *ppos)
 782 {
 783         enum v4l2_field field;
 784         unsigned long flags = 0;
 785         int retval;
 786
 787         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 788
 789         /* setup stuff */
 790         q->read_buf = videobuf_alloc_vb(q);
 791         if (NULL == q->read_buf)
 792                 return -ENOMEM;
 793
 794         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 795         q->read_buf->baddr  = (unsigned long)data;
 796         q->read_buf->bsize  = count;
 797
 798         field = videobuf_next_field(q);
 799         retval = q->ops->buf_prepare(q, q->read_buf, field);
 800         if (0 != retval)
 801                 goto done;
 802
 803         /* start capture & wait */
 804         spin_lock_irqsave(q->irqlock, flags);
 805         q->ops->buf_queue(q, q->read_buf);
 806         spin_unlock_irqrestore(q->irqlock, flags);
 807         retval = videobuf_waiton(q, q->read_buf, 0, 0);
 808         if (0 == retval) {
 809                 CALL(q, sync, q, q->read_buf);
 810                 if (VIDEOBUF_ERROR == q->read_buf->state)
 811                         retval = -EIO;
 812                 else
 813                         retval = q->read_buf->size;
 814         }
 815
 816 done:
 817         /* cleanup */
 818         q->ops->buf_release(q, q->read_buf);
 819         kfree(q->read_buf);
 820         q->read_buf = NULL;
 821         return retval;
 822 }
 823
 824 static int __videobuf_copy_to_user(struct videobuf_queue *q,
 825                                    struct videobuf_buffer *buf,
 826                                    char __user *data, size_t count,
 827                                    int nonblocking)
 828 {
 829         void *vaddr = CALL(q, vaddr, buf);
 830
 831         /* copy to userspace */
 832         if (count > buf->size - q->read_off)
 833                 count = buf->size - q->read_off;
 834
 835         if (copy_to_user(data, vaddr + q->read_off, count))
 836                 return -EFAULT;
 837
 838         return count;
 839 }
 840
 841 static int __videobuf_copy_stream(struct videobuf_queue *q,
 842                                   struct videobuf_buffer *buf,
 843                                   char __user *data, size_t count, size_t pos,
 844                                   int vbihack, int nonblocking)
 845 {
 846         unsigned int *fc = CALL(q, vaddr, buf);
 847
 848         if (vbihack) {
 849                 /* dirty, undocumented hack -- pass the frame counter
 850                         * within the last four bytes of each vbi data block.
 851                         * We need that one to maintain backward compatibility
 852                         * to all vbi decoding software out there ... */
 853                 fc += (buf->size >> 2) - 1;
 854                 *fc = buf->field_count >> 1;
 855                 dprintk(1, "vbihack: %d\n", *fc);
 856         }
 857
 858         /* copy stuff using the common method */
 859         count = __videobuf_copy_to_user(q, buf, data, count, nonblocking);
 860
 861         if ((count == -EFAULT) && (pos == 0))
 862                 return -EFAULT;
 863
 864         return count;
 865 }
 866
 867 ssize_t videobuf_read_one(struct videobuf_queue *q,
 868                           char __user *data, size_t count, loff_t *ppos,
 869                           int nonblocking)
 870 {
 871         enum v4l2_field field;
 872         unsigned long flags = 0;
 873         unsigned size = 0, nbufs = 1;
 874         int retval;
 875
 876         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 877
 878         videobuf_queue_lock(q);
 879
 880         q->ops->buf_setup(q, &nbufs, &size);
 881
 882         if (NULL == q->read_buf  &&
 883             count >= size        &&
 884             !nonblocking) {
 885                 retval = videobuf_read_zerocopy(q, data, count, ppos);
 886                 if (retval >= 0  ||  retval == -EIO)
 887                         /* ok, all done */
 888                         goto done;
 889                 /* fallback to kernel bounce buffer on failures */
 890         }
 891
 892         if (NULL == q->read_buf) {
 893                 /* need to capture a new frame */
 894                 retval = -ENOMEM;
 895                 q->read_buf = videobuf_alloc_vb(q);
 896
 897                 dprintk(1, "video alloc=0x%p\n", q->read_buf);
 898                 if (NULL == q->read_buf)
 899                         goto done;
 900                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 901                 q->read_buf->bsize = count; /* preferred size */
 902                 field = videobuf_next_field(q);
 903                 retval = q->ops->buf_prepare(q, q->read_buf, field);
 904
 905                 if (0 != retval) {
 906                         kfree(q->read_buf);
 907                         q->read_buf = NULL;
 908                         goto done;
 909                 }
 910
 911                 spin_lock_irqsave(q->irqlock, flags);
 912                 q->ops->buf_queue(q, q->read_buf);
 913                 spin_unlock_irqrestore(q->irqlock, flags);
 914
 915                 q->read_off = 0;
 916         }
 917
 918         /* wait until capture is done */
 919         retval = videobuf_waiton(q, q->read_buf, nonblocking, 1);
 920         if (0 != retval)
 921                 goto done;
 922
 923         CALL(q, sync, q, q->read_buf);
 924
 925         if (VIDEOBUF_ERROR == q->read_buf->state) {
 926                 /* catch I/O errors */
 927                 q->ops->buf_release(q, q->read_buf);
 928                 kfree(q->read_buf);
 929                 q->read_buf = NULL;
 930                 retval = -EIO;
 931                 goto done;
 932         }
 933
 934         /* Copy to userspace */
 935         retval = __videobuf_copy_to_user(q, q->read_buf, data, count, nonblocking);
 936         if (retval < 0)
 937                 goto done;
 938
 939         q->read_off += retval;
 940         if (q->read_off == q->read_buf->size) {
 941                 /* all data copied, cleanup */
 942                 q->ops->buf_release(q, q->read_buf);
 943                 kfree(q->read_buf);
 944                 q->read_buf = NULL;
 945         }
 946
 947 done:
 948         videobuf_queue_unlock(q);
 949         return retval;
 950 }
 951 EXPORT_SYMBOL_GPL(videobuf_read_one);
 952
 953 /* Locking: Caller holds q->vb_lock */
 954 static int __videobuf_read_start(struct videobuf_queue *q)
 955 {
 956         enum v4l2_field field;
 957         unsigned long flags = 0;
 958         unsigned int count = 0, size = 0;
 959         int err, i;
 960
 961         q->ops->buf_setup(q, &count, &size);
 962         if (count < 2)
 963                 count = 2;
 964         if (count > VIDEO_MAX_FRAME)
 965                 count = VIDEO_MAX_FRAME;
 966         size = PAGE_ALIGN(size);
 967
 968         err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
 969         if (err < 0)
 970                 return err;
 971
 972         count = err;
 973
 974         for (i = 0; i < count; i++) {
 975                 field = videobuf_next_field(q);
 976                 err = q->ops->buf_prepare(q, q->bufs[i], field);
 977                 if (err)
 978                         return err;
 979                 list_add_tail(&q->bufs[i]->stream, &q->stream);
 980         }
 981         spin_lock_irqsave(q->irqlock, flags);
 982         for (i = 0; i < count; i++)
 983                 q->ops->buf_queue(q, q->bufs[i]);
 984         spin_unlock_irqrestore(q->irqlock, flags);
 985         q->reading = 1;
 986         return 0;
 987 }
 988
 989 static void __videobuf_read_stop(struct videobuf_queue *q)
 990 {
 991         int i;
 992
 993         videobuf_queue_cancel(q);
 994         __videobuf_free(q);
 995         INIT_LIST_HEAD(&q->stream);
 996         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 997                 if (NULL == q->bufs[i])
 998                         continue;
 999                 kfree(q->bufs[i]);
1000                 q->bufs[i] = NULL;
1001         }
1002         q->read_buf = NULL;
1003 }
1004
1005 int videobuf_read_start(struct videobuf_queue *q)
1006 {
1007         int rc;
1008
1009         videobuf_queue_lock(q);
1010         rc = __videobuf_read_start(q);
1011         videobuf_queue_unlock(q);
1012
1013         return rc;
1014 }
1015 EXPORT_SYMBOL_GPL(videobuf_read_start);
1016
1017 void videobuf_read_stop(struct videobuf_queue *q)
1018 {
1019         videobuf_queue_lock(q);
1020         __videobuf_read_stop(q);
1021         videobuf_queue_unlock(q);
1022 }
1023 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1024
1025 void videobuf_stop(struct videobuf_queue *q)
1026 {
1027         videobuf_queue_lock(q);
1028
1029         if (q->streaming)
1030                 __videobuf_streamoff(q);
1031
1032         if (q->reading)
1033                 __videobuf_read_stop(q);
1034
1035         videobuf_queue_unlock(q);
1036 }
1037 EXPORT_SYMBOL_GPL(videobuf_stop);
1038
1039 ssize_t videobuf_read_stream(struct videobuf_queue *q,
1040                              char __user *data, size_t count, loff_t *ppos,
1041                              int vbihack, int nonblocking)
1042 {
1043         int rc, retval;
1044         unsigned long flags = 0;
1045
1046         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1047
1048         dprintk(2, "%s\n", __func__);
1049         videobuf_queue_lock(q);
1050         retval = -EBUSY;
1051         if (q->streaming)
1052                 goto done;
1053         if (!q->reading) {
1054                 retval = __videobuf_read_start(q);
1055                 if (retval < 0)
1056                         goto done;
1057         }
1058
1059         retval = 0;
1060         while (count > 0) {
1061                 /* get / wait for data */
1062                 if (NULL == q->read_buf) {
1063                         q->read_buf = list_entry(q->stream.next,
1064                                                  struct videobuf_buffer,
1065                                                  stream);
1066                         list_del(&q->read_buf->stream);
1067                         q->read_off = 0;
1068                 }
1069                 rc = videobuf_waiton(q, q->read_buf, nonblocking, 1);
1070                 if (rc < 0) {
1071                         if (0 == retval)
1072                                 retval = rc;
1073                         break;
1074                 }
1075
1076                 if (q->read_buf->state == VIDEOBUF_DONE) {
1077                         rc = __videobuf_copy_stream(q, q->read_buf, data + retval, count,
1078                                         retval, vbihack, nonblocking);
1079                         if (rc < 0) {
1080                                 retval = rc;
1081                                 break;
1082                         }
1083                         retval      += rc;
1084                         count       -= rc;
1085                         q->read_off += rc;
1086                 } else {
1087                         /* some error */
1088                         q->read_off = q->read_buf->size;
1089                         if (0 == retval)
1090                                 retval = -EIO;
1091                 }
1092
1093                 /* requeue buffer when done with copying */
1094                 if (q->read_off == q->read_buf->size) {
1095                         list_add_tail(&q->read_buf->stream,
1096                                       &q->stream);
1097                         spin_lock_irqsave(q->irqlock, flags);
1098                         q->ops->buf_queue(q, q->read_buf);
1099                         spin_unlock_irqrestore(q->irqlock, flags);
1100                         q->read_buf = NULL;
1101                 }
1102                 if (retval < 0)
1103                         break;
1104         }
1105
1106 done:
1107         videobuf_queue_unlock(q);
1108         return retval;
1109 }
1110 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1111
1112 unsigned int videobuf_poll_stream(struct file *file,
1113                                   struct videobuf_queue *q,
1114                                   poll_table *wait)
1115 {
1116         unsigned long req_events = poll_requested_events(wait);
1117         struct videobuf_buffer *buf = NULL;
1118         unsigned int rc = 0;
1119
1120         videobuf_queue_lock(q);
1121         if (q->streaming) {
1122                 if (!list_empty(&q->stream))
1123                         buf = list_entry(q->stream.next,
1124                                          struct videobuf_buffer, stream);
1125         } else if (req_events & (POLLIN | POLLRDNORM)) {
1126                 if (!q->reading)
1127                         __videobuf_read_start(q);
1128                 if (!q->reading) {
1129                         rc = POLLERR;
1130                 } else if (NULL == q->read_buf) {
1131                         q->read_buf = list_entry(q->stream.next,
1132                                                  struct videobuf_buffer,
1133                                                  stream);
1134                         list_del(&q->read_buf->stream);
1135                         q->read_off = 0;
1136                 }
1137                 buf = q->read_buf;
1138         }
1139         if (!buf)
1140                 rc = POLLERR;
1141
1142         if (0 == rc) {
1143                 poll_wait(file, &buf->done, wait);
1144                 if (buf->state == VIDEOBUF_DONE ||
1145                     buf->state == VIDEOBUF_ERROR) {
1146                         switch (q->type) {
1147                         case V4L2_BUF_TYPE_VIDEO_OUTPUT:
1148                         case V4L2_BUF_TYPE_VBI_OUTPUT:
1149                         case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
1150                                 rc = POLLOUT | POLLWRNORM;
1151                                 break;
1152                         default:
1153                                 rc = POLLIN | POLLRDNORM;
1154                                 break;
1155                         }
1156                 }
1157         }
1158         videobuf_queue_unlock(q);
1159         return rc;
1160 }
1161 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1162
1163 int videobuf_mmap_mapper(struct videobuf_queue *q, struct vm_area_struct *vma)
1164 {
1165         int rc = -EINVAL;
1166         int i;
1167
1168         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1169
1170         if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED)) {
1171                 dprintk(1, "mmap appl bug: PROT_WRITE and MAP_SHARED are required\n");
1172                 return -EINVAL;
1173         }
1174
1175         videobuf_queue_lock(q);
1176         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1177                 struct videobuf_buffer *buf = q->bufs[i];
1178
1179                 if (buf && buf->memory == V4L2_MEMORY_MMAP &&
1180                                 buf->boff == (vma->vm_pgoff << PAGE_SHIFT)) {
1181                         rc = CALL(q, mmap_mapper, q, buf, vma);
1182                         break;
1183                 }
1184         }
1185         videobuf_queue_unlock(q);
1186
1187         return rc;
1188 }
1189 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);