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