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