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