SAFE public projects git trees. - safe/jmp/linux-2.6/blob - drivers/media/video/videobuf-core.c

   1 /*
   2  * generic helper functions for handling video4linux capture buffers
   3  *
   4  * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org>
   5  *
   6  * Highly based on video-buf written originally by:
   7  * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
   8  * (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org>
   9  * (c) 2006 Ted Walther and John Sokol
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2
  14  */
  15
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/moduleparam.h>
  19 #include <linux/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         q->is_mmapped = 0;
 325
 326         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 327                 if (NULL == q->bufs[i])
 328                         continue;
 329                 q->ops->buf_release(q, q->bufs[i]);
 330                 kfree(q->bufs[i]);
 331                 q->bufs[i] = NULL;
 332         }
 333
 334         return 0;
 335 }
 336
 337 int videobuf_mmap_free(struct videobuf_queue *q)
 338 {
 339         int ret;
 340         mutex_lock(&q->vb_lock);
 341         ret = __videobuf_mmap_free(q);
 342         mutex_unlock(&q->vb_lock);
 343         return ret;
 344 }
 345 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
 346
 347 /* Locking: Caller holds q->vb_lock */
 348 int __videobuf_mmap_setup(struct videobuf_queue *q,
 349                         unsigned int bcount, unsigned int bsize,
 350                         enum v4l2_memory memory)
 351 {
 352         unsigned int i;
 353         int err;
 354
 355         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 356
 357         err = __videobuf_mmap_free(q);
 358         if (0 != err)
 359                 return err;
 360
 361         /* Allocate and initialize buffers */
 362         for (i = 0; i < bcount; i++) {
 363                 q->bufs[i] = videobuf_alloc(q);
 364
 365                 if (NULL == q->bufs[i])
 366                         break;
 367
 368                 q->bufs[i]->i      = i;
 369                 q->bufs[i]->input  = UNSET;
 370                 q->bufs[i]->memory = memory;
 371                 q->bufs[i]->bsize  = bsize;
 372                 switch (memory) {
 373                 case V4L2_MEMORY_MMAP:
 374                         q->bufs[i]->boff = PAGE_ALIGN(bsize) * i;
 375                         break;
 376                 case V4L2_MEMORY_USERPTR:
 377                 case V4L2_MEMORY_OVERLAY:
 378                         /* nothing */
 379                         break;
 380                 }
 381         }
 382
 383         if (!i)
 384                 return -ENOMEM;
 385
 386         dprintk(1, "mmap setup: %d buffers, %d bytes each\n", i, bsize);
 387
 388         return i;
 389 }
 390 EXPORT_SYMBOL_GPL(__videobuf_mmap_setup);
 391
 392 int videobuf_mmap_setup(struct videobuf_queue *q,
 393                         unsigned int bcount, unsigned int bsize,
 394                         enum v4l2_memory memory)
 395 {
 396         int ret;
 397         mutex_lock(&q->vb_lock);
 398         ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
 399         mutex_unlock(&q->vb_lock);
 400         return ret;
 401 }
 402 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
 403
 404 int videobuf_reqbufs(struct videobuf_queue *q,
 405                  struct v4l2_requestbuffers *req)
 406 {
 407         unsigned int size, count;
 408         int retval;
 409
 410         if (req->count < 1) {
 411                 dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
 412                 return -EINVAL;
 413         }
 414
 415         if (req->memory != V4L2_MEMORY_MMAP     &&
 416             req->memory != V4L2_MEMORY_USERPTR  &&
 417             req->memory != V4L2_MEMORY_OVERLAY) {
 418                 dprintk(1, "reqbufs: memory type invalid\n");
 419                 return -EINVAL;
 420         }
 421
 422         mutex_lock(&q->vb_lock);
 423         if (req->type != q->type) {
 424                 dprintk(1, "reqbufs: queue type invalid\n");
 425                 retval = -EINVAL;
 426                 goto done;
 427         }
 428
 429         if (q->streaming) {
 430                 dprintk(1, "reqbufs: streaming already exists\n");
 431                 retval = -EBUSY;
 432                 goto done;
 433         }
 434         if (!list_empty(&q->stream)) {
 435                 dprintk(1, "reqbufs: stream running\n");
 436                 retval = -EBUSY;
 437                 goto done;
 438         }
 439
 440         count = req->count;
 441         if (count > VIDEO_MAX_FRAME)
 442                 count = VIDEO_MAX_FRAME;
 443         size = 0;
 444         q->ops->buf_setup(q, &count, &size);
 445         dprintk(1, "reqbufs: bufs=%d, size=0x%x [%u pages total]\n",
 446                 count, size,
 447                 (unsigned int)((count * PAGE_ALIGN(size)) >> PAGE_SHIFT));
 448
 449         retval = __videobuf_mmap_setup(q, count, size, req->memory);
 450         if (retval < 0) {
 451                 dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
 452                 goto done;
 453         }
 454
 455         req->count = retval;
 456         retval = 0;
 457
 458  done:
 459         mutex_unlock(&q->vb_lock);
 460         return retval;
 461 }
 462 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
 463
 464 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 465 {
 466         int ret = -EINVAL;
 467
 468         mutex_lock(&q->vb_lock);
 469         if (unlikely(b->type != q->type)) {
 470                 dprintk(1, "querybuf: Wrong type.\n");
 471                 goto done;
 472         }
 473         if (unlikely(b->index >= VIDEO_MAX_FRAME)) {
 474                 dprintk(1, "querybuf: index out of range.\n");
 475                 goto done;
 476         }
 477         if (unlikely(NULL == q->bufs[b->index])) {
 478                 dprintk(1, "querybuf: buffer is null.\n");
 479                 goto done;
 480         }
 481
 482         videobuf_status(q, b, q->bufs[b->index], q->type);
 483
 484         ret = 0;
 485 done:
 486         mutex_unlock(&q->vb_lock);
 487         return ret;
 488 }
 489 EXPORT_SYMBOL_GPL(videobuf_querybuf);
 490
 491 int videobuf_qbuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 492 {
 493         struct videobuf_buffer *buf;
 494         enum v4l2_field field;
 495         unsigned long flags = 0;
 496         int retval;
 497
 498         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 499
 500         if (b->memory == V4L2_MEMORY_MMAP)
 501                 down_read(&current->mm->mmap_sem);
 502
 503         mutex_lock(&q->vb_lock);
 504         retval = -EBUSY;
 505         if (q->reading) {
 506                 dprintk(1, "qbuf: Reading running...\n");
 507                 goto done;
 508         }
 509         retval = -EINVAL;
 510         if (b->type != q->type) {
 511                 dprintk(1, "qbuf: Wrong type.\n");
 512                 goto done;
 513         }
 514         if (b->index >= VIDEO_MAX_FRAME) {
 515                 dprintk(1, "qbuf: index out of range.\n");
 516                 goto done;
 517         }
 518         buf = q->bufs[b->index];
 519         if (NULL == buf) {
 520                 dprintk(1, "qbuf: buffer is null.\n");
 521                 goto done;
 522         }
 523         MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
 524         if (buf->memory != b->memory) {
 525                 dprintk(1, "qbuf: memory type is wrong.\n");
 526                 goto done;
 527         }
 528         if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
 529                 dprintk(1, "qbuf: buffer is already queued or active.\n");
 530                 goto done;
 531         }
 532
 533         if (b->flags & V4L2_BUF_FLAG_INPUT) {
 534                 if (b->input >= q->inputs) {
 535                         dprintk(1, "qbuf: wrong input.\n");
 536                         goto done;
 537                 }
 538                 buf->input = b->input;
 539         } else {
 540                 buf->input = UNSET;
 541         }
 542
 543         switch (b->memory) {
 544         case V4L2_MEMORY_MMAP:
 545                 if (0 == buf->baddr) {
 546                         dprintk(1, "qbuf: mmap requested "
 547                                    "but buffer addr is zero!\n");
 548                         goto done;
 549                 }
 550                 break;
 551         case V4L2_MEMORY_USERPTR:
 552                 if (b->length < buf->bsize) {
 553                         dprintk(1, "qbuf: buffer length is not enough\n");
 554                         goto done;
 555                 }
 556                 if (VIDEOBUF_NEEDS_INIT != buf->state &&
 557                     buf->baddr != b->m.userptr)
 558                         q->ops->buf_release(q, buf);
 559                 buf->baddr = b->m.userptr;
 560                 break;
 561         case V4L2_MEMORY_OVERLAY:
 562                 buf->boff = b->m.offset;
 563                 break;
 564         default:
 565                 dprintk(1, "qbuf: wrong memory type\n");
 566                 goto done;
 567         }
 568
 569         dprintk(1, "qbuf: requesting next field\n");
 570         field = videobuf_next_field(q);
 571         retval = q->ops->buf_prepare(q, buf, field);
 572         if (0 != retval) {
 573                 dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
 574                 goto done;
 575         }
 576
 577         list_add_tail(&buf->stream, &q->stream);
 578         if (q->streaming) {
 579                 spin_lock_irqsave(q->irqlock, flags);
 580                 q->ops->buf_queue(q, buf);
 581                 spin_unlock_irqrestore(q->irqlock, flags);
 582         }
 583         dprintk(1, "qbuf: succeeded\n");
 584         retval = 0;
 585         wake_up_interruptible_sync(&q->wait);
 586
 587 done:
 588         mutex_unlock(&q->vb_lock);
 589
 590         if (b->memory == V4L2_MEMORY_MMAP)
 591                 up_read(&current->mm->mmap_sem);
 592
 593         return retval;
 594 }
 595 EXPORT_SYMBOL_GPL(videobuf_qbuf);
 596
 597 /* Locking: Caller holds q->vb_lock */
 598 static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
 599 {
 600         int retval;
 601
 602 checks:
 603         if (!q->streaming) {
 604                 dprintk(1, "next_buffer: Not streaming\n");
 605                 retval = -EINVAL;
 606                 goto done;
 607         }
 608
 609         if (list_empty(&q->stream)) {
 610                 if (noblock) {
 611                         retval = -EAGAIN;
 612                         dprintk(2, "next_buffer: no buffers to dequeue\n");
 613                         goto done;
 614                 } else {
 615                         dprintk(2, "next_buffer: waiting on buffer\n");
 616
 617                         /* Drop lock to avoid deadlock with qbuf */
 618                         mutex_unlock(&q->vb_lock);
 619
 620                         /* Checking list_empty and streaming is safe without
 621                          * locks because we goto checks to validate while
 622                          * holding locks before proceeding */
 623                         retval = wait_event_interruptible(q->wait,
 624                                 !list_empty(&q->stream) || !q->streaming);
 625                         mutex_lock(&q->vb_lock);
 626
 627                         if (retval)
 628                                 goto done;
 629
 630                         goto checks;
 631                 }
 632         }
 633
 634         retval = 0;
 635
 636 done:
 637         return retval;
 638 }
 639
 640 /* Locking: Caller holds q->vb_lock */
 641 static int stream_next_buffer(struct videobuf_queue *q,
 642                         struct videobuf_buffer **vb, int nonblocking)
 643 {
 644         int retval;
 645         struct videobuf_buffer *buf = NULL;
 646
 647         retval = stream_next_buffer_check_queue(q, nonblocking);
 648         if (retval)
 649                 goto done;
 650
 651         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 652         retval = videobuf_waiton(buf, nonblocking, 1);
 653         if (retval < 0)
 654                 goto done;
 655
 656         *vb = buf;
 657 done:
 658         return retval;
 659 }
 660
 661 int videobuf_dqbuf(struct videobuf_queue *q,
 662                    struct v4l2_buffer *b, int nonblocking)
 663 {
 664         struct videobuf_buffer *buf = NULL;
 665         int retval;
 666
 667         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 668
 669         mutex_lock(&q->vb_lock);
 670
 671         retval = stream_next_buffer(q, &buf, nonblocking);
 672         if (retval < 0) {
 673                 dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
 674                 goto done;
 675         }
 676
 677         switch (buf->state) {
 678         case VIDEOBUF_ERROR:
 679                 dprintk(1, "dqbuf: state is error\n");
 680                 retval = -EIO;
 681                 CALL(q, sync, q, buf);
 682                 buf->state = VIDEOBUF_IDLE;
 683                 break;
 684         case VIDEOBUF_DONE:
 685                 dprintk(1, "dqbuf: state is done\n");
 686                 CALL(q, sync, q, buf);
 687                 buf->state = VIDEOBUF_IDLE;
 688                 break;
 689         default:
 690                 dprintk(1, "dqbuf: state invalid\n");
 691                 retval = -EINVAL;
 692                 goto done;
 693         }
 694         list_del(&buf->stream);
 695         memset(b, 0, sizeof(*b));
 696         videobuf_status(q, b, buf, q->type);
 697 done:
 698         mutex_unlock(&q->vb_lock);
 699         return retval;
 700 }
 701 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
 702
 703 int videobuf_streamon(struct videobuf_queue *q)
 704 {
 705         struct videobuf_buffer *buf;
 706         unsigned long flags = 0;
 707         int retval;
 708
 709         mutex_lock(&q->vb_lock);
 710         retval = -EBUSY;
 711         if (q->reading)
 712                 goto done;
 713         retval = 0;
 714         if (q->streaming)
 715                 goto done;
 716         q->streaming = 1;
 717         spin_lock_irqsave(q->irqlock, flags);
 718         list_for_each_entry(buf, &q->stream, stream)
 719                 if (buf->state == VIDEOBUF_PREPARED)
 720                         q->ops->buf_queue(q, buf);
 721         spin_unlock_irqrestore(q->irqlock, flags);
 722
 723         wake_up_interruptible_sync(&q->wait);
 724 done:
 725         mutex_unlock(&q->vb_lock);
 726         return retval;
 727 }
 728 EXPORT_SYMBOL_GPL(videobuf_streamon);
 729
 730 /* Locking: Caller holds q->vb_lock */
 731 static int __videobuf_streamoff(struct videobuf_queue *q)
 732 {
 733         if (!q->streaming)
 734                 return -EINVAL;
 735
 736         videobuf_queue_cancel(q);
 737
 738         return 0;
 739 }
 740
 741 int videobuf_streamoff(struct videobuf_queue *q)
 742 {
 743         int retval;
 744
 745         mutex_lock(&q->vb_lock);
 746         retval = __videobuf_streamoff(q);
 747         mutex_unlock(&q->vb_lock);
 748
 749         return retval;
 750 }
 751 EXPORT_SYMBOL_GPL(videobuf_streamoff);
 752
 753 /* Locking: Caller holds q->vb_lock */
 754 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
 755                                       char __user *data,
 756                                       size_t count, loff_t *ppos)
 757 {
 758         enum v4l2_field field;
 759         unsigned long flags = 0;
 760         int retval;
 761
 762         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 763
 764         /* setup stuff */
 765         q->read_buf = videobuf_alloc(q);
 766         if (NULL == q->read_buf)
 767                 return -ENOMEM;
 768
 769         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 770         q->read_buf->baddr  = (unsigned long)data;
 771         q->read_buf->bsize  = count;
 772
 773         field = videobuf_next_field(q);
 774         retval = q->ops->buf_prepare(q, q->read_buf, field);
 775         if (0 != retval)
 776                 goto done;
 777
 778         /* start capture & wait */
 779         spin_lock_irqsave(q->irqlock, flags);
 780         q->ops->buf_queue(q, q->read_buf);
 781         spin_unlock_irqrestore(q->irqlock, flags);
 782         retval = videobuf_waiton(q->read_buf, 0, 0);
 783         if (0 == retval) {
 784                 CALL(q, sync, q, q->read_buf);
 785                 if (VIDEOBUF_ERROR == q->read_buf->state)
 786                         retval = -EIO;
 787                 else
 788                         retval = q->read_buf->size;
 789         }
 790
 791 done:
 792         /* cleanup */
 793         q->ops->buf_release(q, q->read_buf);
 794         kfree(q->read_buf);
 795         q->read_buf = NULL;
 796         return retval;
 797 }
 798
 799 ssize_t videobuf_read_one(struct videobuf_queue *q,
 800                           char __user *data, size_t count, loff_t *ppos,
 801                           int nonblocking)
 802 {
 803         enum v4l2_field field;
 804         unsigned long flags = 0;
 805         unsigned size = 0, nbufs = 1;
 806         int retval;
 807
 808         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 809
 810         mutex_lock(&q->vb_lock);
 811
 812         q->ops->buf_setup(q, &nbufs, &size);
 813
 814         if (NULL == q->read_buf  &&
 815             count >= size        &&
 816             !nonblocking) {
 817                 retval = videobuf_read_zerocopy(q, data, count, ppos);
 818                 if (retval >= 0  ||  retval == -EIO)
 819                         /* ok, all done */
 820                         goto done;
 821                 /* fallback to kernel bounce buffer on failures */
 822         }
 823
 824         if (NULL == q->read_buf) {
 825                 /* need to capture a new frame */
 826                 retval = -ENOMEM;
 827                 q->read_buf = videobuf_alloc(q);
 828
 829                 dprintk(1, "video alloc=0x%p\n", q->read_buf);
 830                 if (NULL == q->read_buf)
 831                         goto done;
 832                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 833                 q->read_buf->bsize = count; /* preferred size */
 834                 field = videobuf_next_field(q);
 835                 retval = q->ops->buf_prepare(q, q->read_buf, field);
 836
 837                 if (0 != retval) {
 838                         kfree(q->read_buf);
 839                         q->read_buf = NULL;
 840                         goto done;
 841                 }
 842
 843                 spin_lock_irqsave(q->irqlock, flags);
 844                 q->ops->buf_queue(q, q->read_buf);
 845                 spin_unlock_irqrestore(q->irqlock, flags);
 846
 847                 q->read_off = 0;
 848         }
 849
 850         /* wait until capture is done */
 851         retval = videobuf_waiton(q->read_buf, nonblocking, 1);
 852         if (0 != retval)
 853                 goto done;
 854
 855         CALL(q, sync, q, q->read_buf);
 856
 857         if (VIDEOBUF_ERROR == q->read_buf->state) {
 858                 /* catch I/O errors */
 859                 q->ops->buf_release(q, q->read_buf);
 860                 kfree(q->read_buf);
 861                 q->read_buf = NULL;
 862                 retval = -EIO;
 863                 goto done;
 864         }
 865
 866         /* Copy to userspace */
 867         retval = CALL(q, video_copy_to_user, q, data, count, nonblocking);
 868         if (retval < 0)
 869                 goto done;
 870
 871         q->read_off += retval;
 872         if (q->read_off == q->read_buf->size) {
 873                 /* all data copied, cleanup */
 874                 q->ops->buf_release(q, q->read_buf);
 875                 kfree(q->read_buf);
 876                 q->read_buf = NULL;
 877         }
 878
 879 done:
 880         mutex_unlock(&q->vb_lock);
 881         return retval;
 882 }
 883 EXPORT_SYMBOL_GPL(videobuf_read_one);
 884
 885 /* Locking: Caller holds q->vb_lock */
 886 static int __videobuf_read_start(struct videobuf_queue *q)
 887 {
 888         enum v4l2_field field;
 889         unsigned long flags = 0;
 890         unsigned int count = 0, size = 0;
 891         int err, i;
 892
 893         q->ops->buf_setup(q, &count, &size);
 894         if (count < 2)
 895                 count = 2;
 896         if (count > VIDEO_MAX_FRAME)
 897                 count = VIDEO_MAX_FRAME;
 898         size = PAGE_ALIGN(size);
 899
 900         err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
 901         if (err < 0)
 902                 return err;
 903
 904         count = err;
 905
 906         for (i = 0; i < count; i++) {
 907                 field = videobuf_next_field(q);
 908                 err = q->ops->buf_prepare(q, q->bufs[i], field);
 909                 if (err)
 910                         return err;
 911                 list_add_tail(&q->bufs[i]->stream, &q->stream);
 912         }
 913         spin_lock_irqsave(q->irqlock, flags);
 914         for (i = 0; i < count; i++)
 915                 q->ops->buf_queue(q, q->bufs[i]);
 916         spin_unlock_irqrestore(q->irqlock, flags);
 917         q->reading = 1;
 918         return 0;
 919 }
 920
 921 static void __videobuf_read_stop(struct videobuf_queue *q)
 922 {
 923         int i;
 924
 925         videobuf_queue_cancel(q);
 926         __videobuf_mmap_free(q);
 927         INIT_LIST_HEAD(&q->stream);
 928         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 929                 if (NULL == q->bufs[i])
 930                         continue;
 931                 kfree(q->bufs[i]);
 932                 q->bufs[i] = NULL;
 933         }
 934         q->read_buf = NULL;
 935 }
 936
 937 int videobuf_read_start(struct videobuf_queue *q)
 938 {
 939         int rc;
 940
 941         mutex_lock(&q->vb_lock);
 942         rc = __videobuf_read_start(q);
 943         mutex_unlock(&q->vb_lock);
 944
 945         return rc;
 946 }
 947 EXPORT_SYMBOL_GPL(videobuf_read_start);
 948
 949 void videobuf_read_stop(struct videobuf_queue *q)
 950 {
 951         mutex_lock(&q->vb_lock);
 952         __videobuf_read_stop(q);
 953         mutex_unlock(&q->vb_lock);
 954 }
 955 EXPORT_SYMBOL_GPL(videobuf_read_stop);
 956
 957 void videobuf_stop(struct videobuf_queue *q)
 958 {
 959         mutex_lock(&q->vb_lock);
 960
 961         if (q->streaming)
 962                 __videobuf_streamoff(q);
 963
 964         if (q->reading)
 965                 __videobuf_read_stop(q);
 966
 967         mutex_unlock(&q->vb_lock);
 968 }
 969 EXPORT_SYMBOL_GPL(videobuf_stop);
 970
 971 ssize_t videobuf_read_stream(struct videobuf_queue *q,
 972                              char __user *data, size_t count, loff_t *ppos,
 973                              int vbihack, int nonblocking)
 974 {
 975         int rc, retval;
 976         unsigned long flags = 0;
 977
 978         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 979
 980         dprintk(2, "%s\n", __func__);
 981         mutex_lock(&q->vb_lock);
 982         retval = -EBUSY;
 983         if (q->streaming)
 984                 goto done;
 985         if (!q->reading) {
 986                 retval = __videobuf_read_start(q);
 987                 if (retval < 0)
 988                         goto done;
 989         }
 990
 991         retval = 0;
 992         while (count > 0) {
 993                 /* get / wait for data */
 994                 if (NULL == q->read_buf) {
 995                         q->read_buf = list_entry(q->stream.next,
 996                                                  struct videobuf_buffer,
 997                                                  stream);
 998                         list_del(&q->read_buf->stream);
 999                         q->read_off = 0;
1000                 }
1001                 rc = videobuf_waiton(q->read_buf, nonblocking, 1);
1002                 if (rc < 0) {
1003                         if (0 == retval)
1004                                 retval = rc;
1005                         break;
1006                 }
1007
1008                 if (q->read_buf->state == VIDEOBUF_DONE) {
1009                         rc = CALL(q, copy_stream, q, data + retval, count,
1010                                         retval, vbihack, nonblocking);
1011                         if (rc < 0) {
1012                                 retval = rc;
1013                                 break;
1014                         }
1015                         retval      += rc;
1016                         count       -= rc;
1017                         q->read_off += rc;
1018                 } else {
1019                         /* some error */
1020                         q->read_off = q->read_buf->size;
1021                         if (0 == retval)
1022                                 retval = -EIO;
1023                 }
1024
1025                 /* requeue buffer when done with copying */
1026                 if (q->read_off == q->read_buf->size) {
1027                         list_add_tail(&q->read_buf->stream,
1028                                       &q->stream);
1029                         spin_lock_irqsave(q->irqlock, flags);
1030                         q->ops->buf_queue(q, q->read_buf);
1031                         spin_unlock_irqrestore(q->irqlock, flags);
1032                         q->read_buf = NULL;
1033                 }
1034                 if (retval < 0)
1035                         break;
1036         }
1037
1038 done:
1039         mutex_unlock(&q->vb_lock);
1040         return retval;
1041 }
1042 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1043
1044 unsigned int videobuf_poll_stream(struct file *file,
1045                                   struct videobuf_queue *q,
1046                                   poll_table *wait)
1047 {
1048         struct videobuf_buffer *buf = NULL;
1049         unsigned int rc = 0;
1050
1051         mutex_lock(&q->vb_lock);
1052         if (q->streaming) {
1053                 if (!list_empty(&q->stream))
1054                         buf = list_entry(q->stream.next,
1055                                          struct videobuf_buffer, stream);
1056         } else {
1057                 if (!q->reading)
1058                         __videobuf_read_start(q);
1059                 if (!q->reading) {
1060                         rc = POLLERR;
1061                 } else if (NULL == q->read_buf) {
1062                         q->read_buf = list_entry(q->stream.next,
1063                                                  struct videobuf_buffer,
1064                                                  stream);
1065                         list_del(&q->read_buf->stream);
1066                         q->read_off = 0;
1067                 }
1068                 buf = q->read_buf;
1069         }
1070         if (!buf)
1071                 rc = POLLERR;
1072
1073         if (0 == rc) {
1074                 poll_wait(file, &buf->done, wait);
1075                 if (buf->state == VIDEOBUF_DONE ||
1076                     buf->state == VIDEOBUF_ERROR)
1077                         rc = POLLIN|POLLRDNORM;
1078         }
1079         mutex_unlock(&q->vb_lock);
1080         return rc;
1081 }
1082 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1083
1084 int videobuf_mmap_mapper(struct videobuf_queue *q, struct vm_area_struct *vma)
1085 {
1086         int retval;
1087
1088         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1089
1090         mutex_lock(&q->vb_lock);
1091         retval = CALL(q, mmap_mapper, q, vma);
1092         q->is_mmapped = 1;
1093         mutex_unlock(&q->vb_lock);
1094
1095         return retval;
1096 }
1097 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
1098
1099 #ifdef CONFIG_VIDEO_V4L1_COMPAT
1100 int videobuf_cgmbuf(struct videobuf_queue *q,
1101                     struct video_mbuf *mbuf, int count)
1102 {
1103         struct v4l2_requestbuffers req;
1104         int rc, i;
1105
1106         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1107
1108         memset(&req, 0, sizeof(req));
1109         req.type   = q->type;
1110         req.count  = count;
1111         req.memory = V4L2_MEMORY_MMAP;
1112         rc = videobuf_reqbufs(q, &req);
1113         if (rc < 0)
1114                 return rc;
1115
1116         mbuf->frames = req.count;
1117         mbuf->size   = 0;
1118         for (i = 0; i < mbuf->frames; i++) {
1119                 mbuf->offsets[i]  = q->bufs[i]->boff;
1120                 mbuf->size       += PAGE_ALIGN(q->bufs[i]->bsize);
1121         }
1122
1123         return 0;
1124 }
1125 EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
1126 #endif
1127