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 #define WAITON_CONDITION (vb->state != VIDEOBUF_ACTIVE &&\
  68                                 vb->state != VIDEOBUF_QUEUED)
  69 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
  70 {
  71         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
  72
  73         if (non_blocking) {
  74                 if (WAITON_CONDITION)
  75                         return 0;
  76                 else
  77                         return -EAGAIN;
  78         }
  79
  80         if (intr)
  81                 return wait_event_interruptible(vb->done, WAITON_CONDITION);
  82         else
  83                 wait_event(vb->done, WAITON_CONDITION);
  84
  85         return 0;
  86 }
  87
  88 int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
  89                     struct v4l2_framebuffer *fbuf)
  90 {
  91         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
  92         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
  93
  94         return CALL(q, iolock, q, vb, fbuf);
  95 }
  96
  97 /* --------------------------------------------------------------------- */
  98
  99
 100 void videobuf_queue_core_init(struct videobuf_queue *q,
 101                          struct videobuf_queue_ops *ops,
 102                          struct device *dev,
 103                          spinlock_t *irqlock,
 104                          enum v4l2_buf_type type,
 105                          enum v4l2_field field,
 106                          unsigned int msize,
 107                          void *priv,
 108                          struct videobuf_qtype_ops *int_ops)
 109 {
 110         memset(q, 0, sizeof(*q));
 111         q->irqlock   = irqlock;
 112         q->dev       = dev;
 113         q->type      = type;
 114         q->field     = field;
 115         q->msize     = msize;
 116         q->ops       = ops;
 117         q->priv_data = priv;
 118         q->int_ops   = int_ops;
 119
 120         /* All buffer operations are mandatory */
 121         BUG_ON(!q->ops->buf_setup);
 122         BUG_ON(!q->ops->buf_prepare);
 123         BUG_ON(!q->ops->buf_queue);
 124         BUG_ON(!q->ops->buf_release);
 125
 126         /* Lock is mandatory for queue_cancel to work */
 127         BUG_ON(!irqlock);
 128
 129         /* Having implementations for abstract methods are mandatory */
 130         BUG_ON(!q->int_ops);
 131
 132         mutex_init(&q->vb_lock);
 133         init_waitqueue_head(&q->wait);
 134         INIT_LIST_HEAD(&q->stream);
 135 }
 136
 137 /* Locking: Only usage in bttv unsafe find way to remove */
 138 int videobuf_queue_is_busy(struct videobuf_queue *q)
 139 {
 140         int i;
 141
 142         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 143
 144         if (q->streaming) {
 145                 dprintk(1, "busy: streaming active\n");
 146                 return 1;
 147         }
 148         if (q->reading) {
 149                 dprintk(1, "busy: pending read #1\n");
 150                 return 1;
 151         }
 152         if (q->read_buf) {
 153                 dprintk(1, "busy: pending read #2\n");
 154                 return 1;
 155         }
 156         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 157                 if (NULL == q->bufs[i])
 158                         continue;
 159                 if (q->bufs[i]->map) {
 160                         dprintk(1, "busy: buffer #%d mapped\n", i);
 161                         return 1;
 162                 }
 163                 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
 164                         dprintk(1, "busy: buffer #%d queued\n", i);
 165                         return 1;
 166                 }
 167                 if (q->bufs[i]->state == VIDEOBUF_ACTIVE) {
 168                         dprintk(1, "busy: buffer #%d avtive\n", i);
 169                         return 1;
 170                 }
 171         }
 172         return 0;
 173 }
 174
 175 /* Locking: Caller holds q->vb_lock */
 176 void videobuf_queue_cancel(struct videobuf_queue *q)
 177 {
 178         unsigned long flags = 0;
 179         int i;
 180
 181         q->streaming = 0;
 182         q->reading  = 0;
 183         wake_up_interruptible_sync(&q->wait);
 184
 185         /* remove queued buffers from list */
 186         spin_lock_irqsave(q->irqlock, flags);
 187         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 188                 if (NULL == q->bufs[i])
 189                         continue;
 190                 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
 191                         list_del(&q->bufs[i]->queue);
 192                         q->bufs[i]->state = VIDEOBUF_ERROR;
 193                         wake_up_all(&q->bufs[i]->done);
 194                 }
 195         }
 196         spin_unlock_irqrestore(q->irqlock, flags);
 197
 198         /* free all buffers + clear queue */
 199         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 200                 if (NULL == q->bufs[i])
 201                         continue;
 202                 q->ops->buf_release(q, q->bufs[i]);
 203         }
 204         INIT_LIST_HEAD(&q->stream);
 205 }
 206
 207 /* --------------------------------------------------------------------- */
 208
 209 /* Locking: Caller holds q->vb_lock */
 210 enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
 211 {
 212         enum v4l2_field field = q->field;
 213
 214         BUG_ON(V4L2_FIELD_ANY == field);
 215
 216         if (V4L2_FIELD_ALTERNATE == field) {
 217                 if (V4L2_FIELD_TOP == q->last) {
 218                         field   = V4L2_FIELD_BOTTOM;
 219                         q->last = V4L2_FIELD_BOTTOM;
 220                 } else {
 221                         field   = V4L2_FIELD_TOP;
 222                         q->last = V4L2_FIELD_TOP;
 223                 }
 224         }
 225         return field;
 226 }
 227
 228 /* Locking: Caller holds q->vb_lock */
 229 static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
 230                             struct videobuf_buffer *vb, enum v4l2_buf_type type)
 231 {
 232         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
 233         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 234
 235         b->index    = vb->i;
 236         b->type     = type;
 237
 238         b->memory   = vb->memory;
 239         switch (b->memory) {
 240         case V4L2_MEMORY_MMAP:
 241                 b->m.offset  = vb->boff;
 242                 b->length    = vb->bsize;
 243                 break;
 244         case V4L2_MEMORY_USERPTR:
 245                 b->m.userptr = vb->baddr;
 246                 b->length    = vb->bsize;
 247                 break;
 248         case V4L2_MEMORY_OVERLAY:
 249                 b->m.offset  = vb->boff;
 250                 break;
 251         }
 252
 253         b->flags    = 0;
 254         if (vb->map)
 255                 b->flags |= V4L2_BUF_FLAG_MAPPED;
 256
 257         switch (vb->state) {
 258         case VIDEOBUF_PREPARED:
 259         case VIDEOBUF_QUEUED:
 260         case VIDEOBUF_ACTIVE:
 261                 b->flags |= V4L2_BUF_FLAG_QUEUED;
 262                 break;
 263         case VIDEOBUF_DONE:
 264         case VIDEOBUF_ERROR:
 265                 b->flags |= V4L2_BUF_FLAG_DONE;
 266                 break;
 267         case VIDEOBUF_NEEDS_INIT:
 268         case VIDEOBUF_IDLE:
 269                 /* nothing */
 270                 break;
 271         }
 272
 273         if (vb->input != UNSET) {
 274                 b->flags |= V4L2_BUF_FLAG_INPUT;
 275                 b->input  = vb->input;
 276         }
 277
 278         b->field     = vb->field;
 279         b->timestamp = vb->ts;
 280         b->bytesused = vb->size;
 281         b->sequence  = vb->field_count >> 1;
 282 }
 283
 284 /* Locking: Caller holds q->vb_lock */
 285 static int __videobuf_mmap_free(struct videobuf_queue *q)
 286 {
 287         int i;
 288         int rc;
 289
 290         if (!q)
 291                 return 0;
 292
 293         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 294
 295
 296         rc  = CALL(q, mmap_free, q);
 297
 298         q->is_mmapped = 0;
 299
 300         if (rc < 0)
 301                 return rc;
 302
 303         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 304                 if (NULL == q->bufs[i])
 305                         continue;
 306                 q->ops->buf_release(q, q->bufs[i]);
 307                 kfree(q->bufs[i]);
 308                 q->bufs[i] = NULL;
 309         }
 310
 311         return rc;
 312 }
 313
 314 int videobuf_mmap_free(struct videobuf_queue *q)
 315 {
 316         int ret;
 317         mutex_lock(&q->vb_lock);
 318         ret = __videobuf_mmap_free(q);
 319         mutex_unlock(&q->vb_lock);
 320         return ret;
 321 }
 322
 323 /* Locking: Caller holds q->vb_lock */
 324 static int __videobuf_mmap_setup(struct videobuf_queue *q,
 325                         unsigned int bcount, unsigned int bsize,
 326                         enum v4l2_memory memory)
 327 {
 328         unsigned int i;
 329         int err;
 330
 331         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 332
 333         err = __videobuf_mmap_free(q);
 334         if (0 != err)
 335                 return err;
 336
 337         /* Allocate and initialize buffers */
 338         for (i = 0; i < bcount; i++) {
 339                 q->bufs[i] = videobuf_alloc(q);
 340
 341                 if (q->bufs[i] == NULL)
 342                         break;
 343
 344                 q->bufs[i]->i      = i;
 345                 q->bufs[i]->input  = UNSET;
 346                 q->bufs[i]->memory = memory;
 347                 q->bufs[i]->bsize  = bsize;
 348                 switch (memory) {
 349                 case V4L2_MEMORY_MMAP:
 350                         q->bufs[i]->boff  = bsize * i;
 351                         break;
 352                 case V4L2_MEMORY_USERPTR:
 353                 case V4L2_MEMORY_OVERLAY:
 354                         /* nothing */
 355                         break;
 356                 }
 357         }
 358
 359         if (!i)
 360                 return -ENOMEM;
 361
 362         dprintk(1, "mmap setup: %d buffers, %d bytes each\n",
 363                 i, bsize);
 364
 365         return i;
 366 }
 367
 368 int videobuf_mmap_setup(struct videobuf_queue *q,
 369                         unsigned int bcount, unsigned int bsize,
 370                         enum v4l2_memory memory)
 371 {
 372         int ret;
 373         mutex_lock(&q->vb_lock);
 374         ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
 375         mutex_unlock(&q->vb_lock);
 376         return ret;
 377 }
 378
 379 int videobuf_reqbufs(struct videobuf_queue *q,
 380                  struct v4l2_requestbuffers *req)
 381 {
 382         unsigned int size, count;
 383         int retval;
 384
 385         if (req->count < 1) {
 386                 dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
 387                 return -EINVAL;
 388         }
 389
 390         if (req->memory != V4L2_MEMORY_MMAP     &&
 391             req->memory != V4L2_MEMORY_USERPTR  &&
 392             req->memory != V4L2_MEMORY_OVERLAY) {
 393                 dprintk(1, "reqbufs: memory type invalid\n");
 394                 return -EINVAL;
 395         }
 396
 397         mutex_lock(&q->vb_lock);
 398         if (req->type != q->type) {
 399                 dprintk(1, "reqbufs: queue type invalid\n");
 400                 retval = -EINVAL;
 401                 goto done;
 402         }
 403
 404         if (q->streaming) {
 405                 dprintk(1, "reqbufs: streaming already exists\n");
 406                 retval = -EBUSY;
 407                 goto done;
 408         }
 409         if (!list_empty(&q->stream)) {
 410                 dprintk(1, "reqbufs: stream running\n");
 411                 retval = -EBUSY;
 412                 goto done;
 413         }
 414
 415         count = req->count;
 416         if (count > VIDEO_MAX_FRAME)
 417                 count = VIDEO_MAX_FRAME;
 418         size = 0;
 419         q->ops->buf_setup(q, &count, &size);
 420         size = PAGE_ALIGN(size);
 421         dprintk(1, "reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
 422                 count, size, (count*size)>>PAGE_SHIFT);
 423
 424         retval = __videobuf_mmap_setup(q, count, size, req->memory);
 425         if (retval < 0) {
 426                 dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
 427                 goto done;
 428         }
 429
 430         req->count = retval;
 431
 432  done:
 433         mutex_unlock(&q->vb_lock);
 434         return retval;
 435 }
 436
 437 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 438 {
 439         int ret = -EINVAL;
 440
 441         mutex_lock(&q->vb_lock);
 442         if (unlikely(b->type != q->type)) {
 443                 dprintk(1, "querybuf: Wrong type.\n");
 444                 goto done;
 445         }
 446         if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME)) {
 447                 dprintk(1, "querybuf: index out of range.\n");
 448                 goto done;
 449         }
 450         if (unlikely(NULL == q->bufs[b->index])) {
 451                 dprintk(1, "querybuf: buffer is null.\n");
 452                 goto done;
 453         }
 454
 455         videobuf_status(q, b, q->bufs[b->index], q->type);
 456
 457         ret = 0;
 458 done:
 459         mutex_unlock(&q->vb_lock);
 460         return ret;
 461 }
 462
 463 int videobuf_qbuf(struct videobuf_queue *q,
 464               struct v4l2_buffer *b)
 465 {
 466         struct videobuf_buffer *buf;
 467         enum v4l2_field field;
 468         unsigned long flags = 0;
 469         int retval;
 470
 471         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 472
 473         if (b->memory == V4L2_MEMORY_MMAP)
 474                 down_read(&current->mm->mmap_sem);
 475
 476         mutex_lock(&q->vb_lock);
 477         retval = -EBUSY;
 478         if (q->reading) {
 479                 dprintk(1, "qbuf: Reading running...\n");
 480                 goto done;
 481         }
 482         retval = -EINVAL;
 483         if (b->type != q->type) {
 484                 dprintk(1, "qbuf: Wrong type.\n");
 485                 goto done;
 486         }
 487         if (b->index < 0 || b->index >= VIDEO_MAX_FRAME) {
 488                 dprintk(1, "qbuf: index out of range.\n");
 489                 goto done;
 490         }
 491         buf = q->bufs[b->index];
 492         if (NULL == buf) {
 493                 dprintk(1, "qbuf: buffer is null.\n");
 494                 goto done;
 495         }
 496         MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
 497         if (buf->memory != b->memory) {
 498                 dprintk(1, "qbuf: memory type is wrong.\n");
 499                 goto done;
 500         }
 501         if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
 502                 dprintk(1, "qbuf: buffer is already queued or active.\n");
 503                 goto done;
 504         }
 505
 506         if (b->flags & V4L2_BUF_FLAG_INPUT) {
 507                 if (b->input >= q->inputs) {
 508                         dprintk(1, "qbuf: wrong input.\n");
 509                         goto done;
 510                 }
 511                 buf->input = b->input;
 512         } else {
 513                 buf->input = UNSET;
 514         }
 515
 516         switch (b->memory) {
 517         case V4L2_MEMORY_MMAP:
 518                 if (0 == buf->baddr) {
 519                         dprintk(1, "qbuf: mmap requested "
 520                                    "but buffer addr is zero!\n");
 521                         goto done;
 522                 }
 523                 break;
 524         case V4L2_MEMORY_USERPTR:
 525                 if (b->length < buf->bsize) {
 526                         dprintk(1, "qbuf: buffer length is not enough\n");
 527                         goto done;
 528                 }
 529                 if (VIDEOBUF_NEEDS_INIT != buf->state &&
 530                     buf->baddr != b->m.userptr)
 531                         q->ops->buf_release(q, buf);
 532                 buf->baddr = b->m.userptr;
 533                 break;
 534         case V4L2_MEMORY_OVERLAY:
 535                 buf->boff = b->m.offset;
 536                 break;
 537         default:
 538                 dprintk(1, "qbuf: wrong memory type\n");
 539                 goto done;
 540         }
 541
 542         dprintk(1, "qbuf: requesting next field\n");
 543         field = videobuf_next_field(q);
 544         retval = q->ops->buf_prepare(q, buf, field);
 545         if (0 != retval) {
 546                 dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
 547                 goto done;
 548         }
 549
 550         list_add_tail(&buf->stream, &q->stream);
 551         if (q->streaming) {
 552                 spin_lock_irqsave(q->irqlock, flags);
 553                 q->ops->buf_queue(q, buf);
 554                 spin_unlock_irqrestore(q->irqlock, flags);
 555         }
 556         dprintk(1, "qbuf: succeded\n");
 557         retval = 0;
 558         wake_up_interruptible_sync(&q->wait);
 559
 560  done:
 561         mutex_unlock(&q->vb_lock);
 562
 563         if (b->memory == V4L2_MEMORY_MMAP)
 564                 up_read(&current->mm->mmap_sem);
 565
 566         return retval;
 567 }
 568
 569
 570 /* Locking: Caller holds q->vb_lock */
 571 static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
 572 {
 573         int retval;
 574
 575 checks:
 576         if (!q->streaming) {
 577                 dprintk(1, "next_buffer: Not streaming\n");
 578                 retval = -EINVAL;
 579                 goto done;
 580         }
 581
 582         if (list_empty(&q->stream)) {
 583                 if (noblock) {
 584                         retval = -EAGAIN;
 585                         dprintk(2, "next_buffer: no buffers to dequeue\n");
 586                         goto done;
 587                 } else {
 588                         dprintk(2, "next_buffer: waiting on buffer\n");
 589
 590                         /* Drop lock to avoid deadlock with qbuf */
 591                         mutex_unlock(&q->vb_lock);
 592
 593                         /* Checking list_empty and streaming is safe without
 594                          * locks because we goto checks to validate while
 595                          * holding locks before proceeding */
 596                         retval = wait_event_interruptible(q->wait,
 597                                 !list_empty(&q->stream) || !q->streaming);
 598                         mutex_lock(&q->vb_lock);
 599
 600                         if (retval)
 601                                 goto done;
 602
 603                         goto checks;
 604                 }
 605         }
 606
 607         retval = 0;
 608
 609 done:
 610         return retval;
 611 }
 612
 613
 614 /* Locking: Caller holds q->vb_lock */
 615 static int stream_next_buffer(struct videobuf_queue *q,
 616                         struct videobuf_buffer **vb, int nonblocking)
 617 {
 618         int retval;
 619         struct videobuf_buffer *buf = NULL;
 620
 621         retval = stream_next_buffer_check_queue(q, nonblocking);
 622         if (retval)
 623                 goto done;
 624
 625         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 626         retval = videobuf_waiton(buf, nonblocking, 1);
 627         if (retval < 0)
 628                 goto done;
 629
 630         *vb = buf;
 631 done:
 632         return retval;
 633 }
 634
 635 int videobuf_dqbuf(struct videobuf_queue *q,
 636                struct v4l2_buffer *b, int nonblocking)
 637 {
 638         struct videobuf_buffer *buf = NULL;
 639         int retval;
 640
 641         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 642
 643         mutex_lock(&q->vb_lock);
 644
 645         retval = stream_next_buffer(q, &buf, nonblocking);
 646         if (retval < 0) {
 647                 dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
 648                 goto done;
 649         }
 650
 651         switch (buf->state) {
 652         case VIDEOBUF_ERROR:
 653                 dprintk(1, "dqbuf: state is error\n");
 654                 retval = -EIO;
 655                 CALL(q, sync, q, buf);
 656                 buf->state = VIDEOBUF_IDLE;
 657                 break;
 658         case VIDEOBUF_DONE:
 659                 dprintk(1, "dqbuf: state is done\n");
 660                 CALL(q, sync, q, buf);
 661                 buf->state = VIDEOBUF_IDLE;
 662                 break;
 663         default:
 664                 dprintk(1, "dqbuf: state invalid\n");
 665                 retval = -EINVAL;
 666                 goto done;
 667         }
 668         list_del(&buf->stream);
 669         memset(b, 0, sizeof(*b));
 670         videobuf_status(q, b, buf, q->type);
 671
 672  done:
 673         mutex_unlock(&q->vb_lock);
 674         return retval;
 675 }
 676
 677 int videobuf_streamon(struct videobuf_queue *q)
 678 {
 679         struct videobuf_buffer *buf;
 680         unsigned long flags = 0;
 681         int retval;
 682
 683         mutex_lock(&q->vb_lock);
 684         retval = -EBUSY;
 685         if (q->reading)
 686                 goto done;
 687         retval = 0;
 688         if (q->streaming)
 689                 goto done;
 690         q->streaming = 1;
 691         spin_lock_irqsave(q->irqlock, flags);
 692         list_for_each_entry(buf, &q->stream, stream)
 693                 if (buf->state == VIDEOBUF_PREPARED)
 694                         q->ops->buf_queue(q, buf);
 695         spin_unlock_irqrestore(q->irqlock, flags);
 696
 697         wake_up_interruptible_sync(&q->wait);
 698  done:
 699         mutex_unlock(&q->vb_lock);
 700         return retval;
 701 }
 702
 703 /* Locking: Caller holds q->vb_lock */
 704 static int __videobuf_streamoff(struct videobuf_queue *q)
 705 {
 706         if (!q->streaming)
 707                 return -EINVAL;
 708
 709         videobuf_queue_cancel(q);
 710
 711         return 0;
 712 }
 713
 714 int videobuf_streamoff(struct videobuf_queue *q)
 715 {
 716         int retval;
 717
 718         mutex_lock(&q->vb_lock);
 719         retval = __videobuf_streamoff(q);
 720         mutex_unlock(&q->vb_lock);
 721
 722         return retval;
 723 }
 724
 725 /* Locking: Caller holds q->vb_lock */
 726 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
 727                                       char __user *data,
 728                                       size_t count, loff_t *ppos)
 729 {
 730         enum v4l2_field field;
 731         unsigned long flags = 0;
 732         int retval;
 733
 734         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 735
 736         /* setup stuff */
 737         q->read_buf = videobuf_alloc(q);
 738         if (NULL == q->read_buf)
 739                 return -ENOMEM;
 740
 741         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 742         q->read_buf->baddr  = (unsigned long)data;
 743         q->read_buf->bsize  = count;
 744
 745         field = videobuf_next_field(q);
 746         retval = q->ops->buf_prepare(q, q->read_buf, field);
 747         if (0 != retval)
 748                 goto done;
 749
 750         /* start capture & wait */
 751         spin_lock_irqsave(q->irqlock, flags);
 752         q->ops->buf_queue(q, q->read_buf);
 753         spin_unlock_irqrestore(q->irqlock, flags);
 754         retval = videobuf_waiton(q->read_buf, 0, 0);
 755         if (0 == retval) {
 756                 CALL(q, sync, q, q->read_buf);
 757                 if (VIDEOBUF_ERROR == q->read_buf->state)
 758                         retval = -EIO;
 759                 else
 760                         retval = q->read_buf->size;
 761         }
 762
 763  done:
 764         /* cleanup */
 765         q->ops->buf_release(q, q->read_buf);
 766         kfree(q->read_buf);
 767         q->read_buf = NULL;
 768         return retval;
 769 }
 770
 771 ssize_t videobuf_read_one(struct videobuf_queue *q,
 772                           char __user *data, size_t count, loff_t *ppos,
 773                           int nonblocking)
 774 {
 775         enum v4l2_field field;
 776         unsigned long flags = 0;
 777         unsigned size = 0, nbufs = 1;
 778         int retval;
 779
 780         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 781
 782         mutex_lock(&q->vb_lock);
 783
 784         q->ops->buf_setup(q, &nbufs, &size);
 785
 786         if (NULL == q->read_buf  &&
 787             count >= size        &&
 788             !nonblocking) {
 789                 retval = videobuf_read_zerocopy(q, data, count, ppos);
 790                 if (retval >= 0  ||  retval == -EIO)
 791                         /* ok, all done */
 792                         goto done;
 793                 /* fallback to kernel bounce buffer on failures */
 794         }
 795
 796         if (NULL == q->read_buf) {
 797                 /* need to capture a new frame */
 798                 retval = -ENOMEM;
 799                 q->read_buf = videobuf_alloc(q);
 800
 801                 dprintk(1, "video alloc=0x%p\n", q->read_buf);
 802                 if (NULL == q->read_buf)
 803                         goto done;
 804                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 805                 q->read_buf->bsize = count; /* preferred size */
 806                 field = videobuf_next_field(q);
 807                 retval = q->ops->buf_prepare(q, q->read_buf, field);
 808
 809                 if (0 != retval) {
 810                         kfree(q->read_buf);
 811                         q->read_buf = NULL;
 812                         goto done;
 813                 }
 814
 815                 spin_lock_irqsave(q->irqlock, flags);
 816                 q->ops->buf_queue(q, q->read_buf);
 817                 spin_unlock_irqrestore(q->irqlock, flags);
 818
 819                 q->read_off = 0;
 820         }
 821
 822         /* wait until capture is done */
 823         retval = videobuf_waiton(q->read_buf, nonblocking, 1);
 824         if (0 != retval)
 825                 goto done;
 826
 827         CALL(q, sync, q, q->read_buf);
 828
 829         if (VIDEOBUF_ERROR == q->read_buf->state) {
 830                 /* catch I/O errors */
 831                 q->ops->buf_release(q, q->read_buf);
 832                 kfree(q->read_buf);
 833                 q->read_buf = NULL;
 834                 retval = -EIO;
 835                 goto done;
 836         }
 837
 838         /* Copy to userspace */
 839         retval = CALL(q, video_copy_to_user, q, data, count, nonblocking);
 840         if (retval < 0)
 841                 goto done;
 842
 843         q->read_off += retval;
 844         if (q->read_off == q->read_buf->size) {
 845                 /* all data copied, cleanup */
 846                 q->ops->buf_release(q, q->read_buf);
 847                 kfree(q->read_buf);
 848                 q->read_buf = NULL;
 849         }
 850
 851  done:
 852         mutex_unlock(&q->vb_lock);
 853         return retval;
 854 }
 855
 856 /* Locking: Caller holds q->vb_lock */
 857 static int __videobuf_read_start(struct videobuf_queue *q)
 858 {
 859         enum v4l2_field field;
 860         unsigned long flags = 0;
 861         unsigned int count = 0, size = 0;
 862         int err, i;
 863
 864         q->ops->buf_setup(q, &count, &size);
 865         if (count < 2)
 866                 count = 2;
 867         if (count > VIDEO_MAX_FRAME)
 868                 count = VIDEO_MAX_FRAME;
 869         size = PAGE_ALIGN(size);
 870
 871         err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
 872         if (err < 0)
 873                 return err;
 874
 875         count = err;
 876
 877         for (i = 0; i < count; i++) {
 878                 field = videobuf_next_field(q);
 879                 err = q->ops->buf_prepare(q, q->bufs[i], field);
 880                 if (err)
 881                         return err;
 882                 list_add_tail(&q->bufs[i]->stream, &q->stream);
 883         }
 884         spin_lock_irqsave(q->irqlock, flags);
 885         for (i = 0; i < count; i++)
 886                 q->ops->buf_queue(q, q->bufs[i]);
 887         spin_unlock_irqrestore(q->irqlock, flags);
 888         q->reading = 1;
 889         return 0;
 890 }
 891
 892 static void __videobuf_read_stop(struct videobuf_queue *q)
 893 {
 894         int i;
 895
 896         videobuf_queue_cancel(q);
 897         __videobuf_mmap_free(q);
 898         INIT_LIST_HEAD(&q->stream);
 899         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 900                 if (NULL == q->bufs[i])
 901                         continue;
 902                 kfree(q->bufs[i]);
 903                 q->bufs[i] = NULL;
 904         }
 905         q->read_buf = NULL;
 906
 907 }
 908
 909 int videobuf_read_start(struct videobuf_queue *q)
 910 {
 911         int rc;
 912
 913         mutex_lock(&q->vb_lock);
 914         rc = __videobuf_read_start(q);
 915         mutex_unlock(&q->vb_lock);
 916
 917         return rc;
 918 }
 919
 920 void videobuf_read_stop(struct videobuf_queue *q)
 921 {
 922         mutex_lock(&q->vb_lock);
 923         __videobuf_read_stop(q);
 924         mutex_unlock(&q->vb_lock);
 925 }
 926
 927 void videobuf_stop(struct videobuf_queue *q)
 928 {
 929         mutex_lock(&q->vb_lock);
 930
 931         if (q->streaming)
 932                 __videobuf_streamoff(q);
 933
 934         if (q->reading)
 935                 __videobuf_read_stop(q);
 936
 937         mutex_unlock(&q->vb_lock);
 938 }
 939
 940
 941 ssize_t videobuf_read_stream(struct videobuf_queue *q,
 942                              char __user *data, size_t count, loff_t *ppos,
 943                              int vbihack, int nonblocking)
 944 {
 945         int rc, retval;
 946         unsigned long flags = 0;
 947
 948         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 949
 950         dprintk(2, "%s\n", __func__);
 951         mutex_lock(&q->vb_lock);
 952         retval = -EBUSY;
 953         if (q->streaming)
 954                 goto done;
 955         if (!q->reading) {
 956                 retval = __videobuf_read_start(q);
 957                 if (retval < 0)
 958                         goto done;
 959         }
 960
 961         retval = 0;
 962         while (count > 0) {
 963                 /* get / wait for data */
 964                 if (NULL == q->read_buf) {
 965                         q->read_buf = list_entry(q->stream.next,
 966                                                  struct videobuf_buffer,
 967                                                  stream);
 968                         list_del(&q->read_buf->stream);
 969                         q->read_off = 0;
 970                 }
 971                 rc = videobuf_waiton(q->read_buf, nonblocking, 1);
 972                 if (rc < 0) {
 973                         if (0 == retval)
 974                                 retval = rc;
 975                         break;
 976                 }
 977
 978                 if (q->read_buf->state == VIDEOBUF_DONE) {
 979                         rc = CALL(q, copy_stream, q, data + retval, count,
 980                                         retval, vbihack, nonblocking);
 981                         if (rc < 0) {
 982                                 retval = rc;
 983                                 break;
 984                         }
 985                         retval      += rc;
 986                         count       -= rc;
 987                         q->read_off += rc;
 988                 } else {
 989                         /* some error */
 990                         q->read_off = q->read_buf->size;
 991                         if (0 == retval)
 992                                 retval = -EIO;
 993                 }
 994
 995                 /* requeue buffer when done with copying */
 996                 if (q->read_off == q->read_buf->size) {
 997                         list_add_tail(&q->read_buf->stream,
 998                                       &q->stream);
 999                         spin_lock_irqsave(q->irqlock, flags);
1000                         q->ops->buf_queue(q, q->read_buf);
1001                         spin_unlock_irqrestore(q->irqlock, flags);
1002                         q->read_buf = NULL;
1003                 }
1004                 if (retval < 0)
1005                         break;
1006         }
1007
1008  done:
1009         mutex_unlock(&q->vb_lock);
1010         return retval;
1011 }
1012
1013 unsigned int videobuf_poll_stream(struct file *file,
1014                                   struct videobuf_queue *q,
1015                                   poll_table *wait)
1016 {
1017         struct videobuf_buffer *buf = NULL;
1018         unsigned int rc = 0;
1019
1020         mutex_lock(&q->vb_lock);
1021         if (q->streaming) {
1022                 if (!list_empty(&q->stream))
1023                         buf = list_entry(q->stream.next,
1024                                          struct videobuf_buffer, stream);
1025         } else {
1026                 if (!q->reading)
1027                         __videobuf_read_start(q);
1028                 if (!q->reading) {
1029                         rc = POLLERR;
1030                 } else if (NULL == q->read_buf) {
1031                         q->read_buf = list_entry(q->stream.next,
1032                                                  struct videobuf_buffer,
1033                                                  stream);
1034                         list_del(&q->read_buf->stream);
1035                         q->read_off = 0;
1036                 }
1037                 buf = q->read_buf;
1038         }
1039         if (!buf)
1040                 rc = POLLERR;
1041
1042         if (0 == rc) {
1043                 poll_wait(file, &buf->done, wait);
1044                 if (buf->state == VIDEOBUF_DONE ||
1045                     buf->state == VIDEOBUF_ERROR)
1046                         rc = POLLIN|POLLRDNORM;
1047         }
1048         mutex_unlock(&q->vb_lock);
1049         return rc;
1050 }
1051
1052 int videobuf_mmap_mapper(struct videobuf_queue *q,
1053                          struct vm_area_struct *vma)
1054 {
1055         int retval;
1056
1057         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1058
1059         mutex_lock(&q->vb_lock);
1060         retval = CALL(q, mmap_mapper, q, vma);
1061         q->is_mmapped = 1;
1062         mutex_unlock(&q->vb_lock);
1063
1064         return retval;
1065 }
1066
1067 #ifdef CONFIG_VIDEO_V4L1_COMPAT
1068 int videobuf_cgmbuf(struct videobuf_queue *q,
1069                     struct video_mbuf *mbuf, int count)
1070 {
1071         struct v4l2_requestbuffers req;
1072         int rc, i;
1073
1074         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1075
1076         memset(&req, 0, sizeof(req));
1077         req.type   = q->type;
1078         req.count  = count;
1079         req.memory = V4L2_MEMORY_MMAP;
1080         rc = videobuf_reqbufs(q, &req);
1081         if (rc < 0)
1082                 return rc;
1083
1084         mbuf->frames = req.count;
1085         mbuf->size   = 0;
1086         for (i = 0; i < mbuf->frames; i++) {
1087                 mbuf->offsets[i]  = q->bufs[i]->boff;
1088                 mbuf->size       += q->bufs[i]->bsize;
1089         }
1090
1091         return 0;
1092 }
1093 EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
1094 #endif
1095
1096 /* --------------------------------------------------------------------- */
1097
1098 EXPORT_SYMBOL_GPL(videobuf_waiton);
1099 EXPORT_SYMBOL_GPL(videobuf_iolock);
1100
1101 EXPORT_SYMBOL_GPL(videobuf_alloc);
1102
1103 EXPORT_SYMBOL_GPL(videobuf_queue_core_init);
1104 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
1105 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
1106
1107 EXPORT_SYMBOL_GPL(videobuf_next_field);
1108 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
1109 EXPORT_SYMBOL_GPL(videobuf_querybuf);
1110 EXPORT_SYMBOL_GPL(videobuf_qbuf);
1111 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
1112 EXPORT_SYMBOL_GPL(videobuf_streamon);
1113 EXPORT_SYMBOL_GPL(videobuf_streamoff);
1114
1115 EXPORT_SYMBOL_GPL(videobuf_read_start);
1116 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1117 EXPORT_SYMBOL_GPL(videobuf_stop);
1118 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1119 EXPORT_SYMBOL_GPL(videobuf_read_one);
1120 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1121
1122 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
1123 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
1124 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);