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 #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         /* Having implementations for abstract methods are mandatory */
 127         BUG_ON(!q->int_ops);
 128
 129         mutex_init(&q->vb_lock);
 130         init_waitqueue_head(&q->wait);
 131         INIT_LIST_HEAD(&q->stream);
 132 }
 133
 134 /* Locking: Only usage in bttv unsafe find way to remove */
 135 int videobuf_queue_is_busy(struct videobuf_queue *q)
 136 {
 137         int i;
 138
 139         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 140
 141         if (q->streaming) {
 142                 dprintk(1, "busy: streaming active\n");
 143                 return 1;
 144         }
 145         if (q->reading) {
 146                 dprintk(1, "busy: pending read #1\n");
 147                 return 1;
 148         }
 149         if (q->read_buf) {
 150                 dprintk(1, "busy: pending read #2\n");
 151                 return 1;
 152         }
 153         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 154                 if (NULL == q->bufs[i])
 155                         continue;
 156                 if (q->bufs[i]->map) {
 157                         dprintk(1, "busy: buffer #%d mapped\n", i);
 158                         return 1;
 159                 }
 160                 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
 161                         dprintk(1, "busy: buffer #%d queued\n", i);
 162                         return 1;
 163                 }
 164                 if (q->bufs[i]->state == VIDEOBUF_ACTIVE) {
 165                         dprintk(1, "busy: buffer #%d avtive\n", i);
 166                         return 1;
 167                 }
 168         }
 169         return 0;
 170 }
 171
 172 /* Locking: Caller holds q->vb_lock */
 173 void videobuf_queue_cancel(struct videobuf_queue *q)
 174 {
 175         unsigned long flags = 0;
 176         int i;
 177
 178         q->streaming = 0;
 179         q->reading  = 0;
 180         wake_up_interruptible_sync(&q->wait);
 181
 182         /* remove queued buffers from list */
 183         if (q->irqlock)
 184                 spin_lock_irqsave(q->irqlock, flags);
 185         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 186                 if (NULL == q->bufs[i])
 187                         continue;
 188                 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
 189                         list_del(&q->bufs[i]->queue);
 190                         q->bufs[i]->state = VIDEOBUF_ERROR;
 191                         wake_up_all(&q->bufs[i]->done);
 192                 }
 193         }
 194         if (q->irqlock)
 195                 spin_unlock_irqrestore(q->irqlock, flags);
 196
 197         /* free all buffers + clear queue */
 198         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 199                 if (NULL == q->bufs[i])
 200                         continue;
 201                 q->ops->buf_release(q, q->bufs[i]);
 202         }
 203         INIT_LIST_HEAD(&q->stream);
 204 }
 205
 206 /* --------------------------------------------------------------------- */
 207
 208 /* Locking: Caller holds q->vb_lock */
 209 enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
 210 {
 211         enum v4l2_field field = q->field;
 212
 213         BUG_ON(V4L2_FIELD_ANY == field);
 214
 215         if (V4L2_FIELD_ALTERNATE == field) {
 216                 if (V4L2_FIELD_TOP == q->last) {
 217                         field   = V4L2_FIELD_BOTTOM;
 218                         q->last = V4L2_FIELD_BOTTOM;
 219                 } else {
 220                         field   = V4L2_FIELD_TOP;
 221                         q->last = V4L2_FIELD_TOP;
 222                 }
 223         }
 224         return field;
 225 }
 226
 227 /* Locking: Caller holds q->vb_lock */
 228 static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
 229                             struct videobuf_buffer *vb, enum v4l2_buf_type type)
 230 {
 231         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
 232         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 233
 234         b->index    = vb->i;
 235         b->type     = type;
 236
 237         b->memory   = vb->memory;
 238         switch (b->memory) {
 239         case V4L2_MEMORY_MMAP:
 240                 b->m.offset  = vb->boff;
 241                 b->length    = vb->bsize;
 242                 break;
 243         case V4L2_MEMORY_USERPTR:
 244                 b->m.userptr = vb->baddr;
 245                 b->length    = vb->bsize;
 246                 break;
 247         case V4L2_MEMORY_OVERLAY:
 248                 b->m.offset  = vb->boff;
 249                 break;
 250         }
 251
 252         b->flags    = 0;
 253         if (vb->map)
 254                 b->flags |= V4L2_BUF_FLAG_MAPPED;
 255
 256         switch (vb->state) {
 257         case VIDEOBUF_PREPARED:
 258         case VIDEOBUF_QUEUED:
 259         case VIDEOBUF_ACTIVE:
 260                 b->flags |= V4L2_BUF_FLAG_QUEUED;
 261                 break;
 262         case VIDEOBUF_DONE:
 263         case VIDEOBUF_ERROR:
 264                 b->flags |= V4L2_BUF_FLAG_DONE;
 265                 break;
 266         case VIDEOBUF_NEEDS_INIT:
 267         case VIDEOBUF_IDLE:
 268                 /* nothing */
 269                 break;
 270         }
 271
 272         if (vb->input != UNSET) {
 273                 b->flags |= V4L2_BUF_FLAG_INPUT;
 274                 b->input  = vb->input;
 275         }
 276
 277         b->field     = vb->field;
 278         b->timestamp = vb->ts;
 279         b->bytesused = vb->size;
 280         b->sequence  = vb->field_count >> 1;
 281 }
 282
 283 /* Locking: Caller holds q->vb_lock */
 284 static int __videobuf_mmap_free(struct videobuf_queue *q)
 285 {
 286         int i;
 287         int rc;
 288
 289         if (!q)
 290                 return 0;
 291
 292         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 293
 294
 295         rc  = CALL(q, mmap_free, q);
 296
 297         q->is_mmapped = 0;
 298
 299         if (rc < 0)
 300                 return rc;
 301
 302         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 303                 if (NULL == q->bufs[i])
 304                         continue;
 305                 q->ops->buf_release(q, q->bufs[i]);
 306                 kfree(q->bufs[i]);
 307                 q->bufs[i] = NULL;
 308         }
 309
 310         return rc;
 311 }
 312
 313 int videobuf_mmap_free(struct videobuf_queue *q)
 314 {
 315         int ret;
 316         mutex_lock(&q->vb_lock);
 317         ret = __videobuf_mmap_free(q);
 318         mutex_unlock(&q->vb_lock);
 319         return ret;
 320 }
 321
 322 /* Locking: Caller holds q->vb_lock */
 323 static int __videobuf_mmap_setup(struct videobuf_queue *q,
 324                         unsigned int bcount, unsigned int bsize,
 325                         enum v4l2_memory memory)
 326 {
 327         unsigned int i;
 328         int err;
 329
 330         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 331
 332         err = __videobuf_mmap_free(q);
 333         if (0 != err)
 334                 return err;
 335
 336         /* Allocate and initialize buffers */
 337         for (i = 0; i < bcount; i++) {
 338                 q->bufs[i] = videobuf_alloc(q);
 339
 340                 if (q->bufs[i] == NULL)
 341                         break;
 342
 343                 q->bufs[i]->i      = i;
 344                 q->bufs[i]->input  = UNSET;
 345                 q->bufs[i]->memory = memory;
 346                 q->bufs[i]->bsize  = bsize;
 347                 switch (memory) {
 348                 case V4L2_MEMORY_MMAP:
 349                         q->bufs[i]->boff  = bsize * i;
 350                         break;
 351                 case V4L2_MEMORY_USERPTR:
 352                 case V4L2_MEMORY_OVERLAY:
 353                         /* nothing */
 354                         break;
 355                 }
 356         }
 357
 358         if (!i)
 359                 return -ENOMEM;
 360
 361         dprintk(1, "mmap setup: %d buffers, %d bytes each\n",
 362                 i, bsize);
 363
 364         return i;
 365 }
 366
 367 int videobuf_mmap_setup(struct videobuf_queue *q,
 368                         unsigned int bcount, unsigned int bsize,
 369                         enum v4l2_memory memory)
 370 {
 371         int ret;
 372         mutex_lock(&q->vb_lock);
 373         ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
 374         mutex_unlock(&q->vb_lock);
 375         return ret;
 376 }
 377
 378 int videobuf_reqbufs(struct videobuf_queue *q,
 379                  struct v4l2_requestbuffers *req)
 380 {
 381         unsigned int size, count;
 382         int retval;
 383
 384         if (req->count < 1) {
 385                 dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
 386                 return -EINVAL;
 387         }
 388
 389         if (req->memory != V4L2_MEMORY_MMAP     &&
 390             req->memory != V4L2_MEMORY_USERPTR  &&
 391             req->memory != V4L2_MEMORY_OVERLAY) {
 392                 dprintk(1, "reqbufs: memory type invalid\n");
 393                 return -EINVAL;
 394         }
 395
 396         mutex_lock(&q->vb_lock);
 397         if (req->type != q->type) {
 398                 dprintk(1, "reqbufs: queue type invalid\n");
 399                 retval = -EINVAL;
 400                 goto done;
 401         }
 402
 403         if (q->streaming) {
 404                 dprintk(1, "reqbufs: streaming already exists\n");
 405                 retval = -EBUSY;
 406                 goto done;
 407         }
 408         if (!list_empty(&q->stream)) {
 409                 dprintk(1, "reqbufs: stream running\n");
 410                 retval = -EBUSY;
 411                 goto done;
 412         }
 413
 414         count = req->count;
 415         if (count > VIDEO_MAX_FRAME)
 416                 count = VIDEO_MAX_FRAME;
 417         size = 0;
 418         q->ops->buf_setup(q, &count, &size);
 419         size = PAGE_ALIGN(size);
 420         dprintk(1, "reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
 421                 count, size, (count*size)>>PAGE_SHIFT);
 422
 423         retval = __videobuf_mmap_setup(q, count, size, req->memory);
 424         if (retval < 0) {
 425                 dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
 426                 goto done;
 427         }
 428
 429         req->count = retval;
 430
 431  done:
 432         mutex_unlock(&q->vb_lock);
 433         return retval;
 434 }
 435
 436 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 437 {
 438         int ret = -EINVAL;
 439
 440         mutex_lock(&q->vb_lock);
 441         if (unlikely(b->type != q->type)) {
 442                 dprintk(1, "querybuf: Wrong type.\n");
 443                 goto done;
 444         }
 445         if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME)) {
 446                 dprintk(1, "querybuf: index out of range.\n");
 447                 goto done;
 448         }
 449         if (unlikely(NULL == q->bufs[b->index])) {
 450                 dprintk(1, "querybuf: buffer is null.\n");
 451                 goto done;
 452         }
 453
 454         videobuf_status(q, b, q->bufs[b->index], q->type);
 455
 456         ret = 0;
 457 done:
 458         mutex_unlock(&q->vb_lock);
 459         return ret;
 460 }
 461
 462 int videobuf_qbuf(struct videobuf_queue *q,
 463               struct v4l2_buffer *b)
 464 {
 465         struct videobuf_buffer *buf;
 466         enum v4l2_field field;
 467         unsigned long flags = 0;
 468         int retval;
 469
 470         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 471
 472         if (b->memory == V4L2_MEMORY_MMAP)
 473                 down_read(&current->mm->mmap_sem);
 474
 475         mutex_lock(&q->vb_lock);
 476         retval = -EBUSY;
 477         if (q->reading) {
 478                 dprintk(1, "qbuf: Reading running...\n");
 479                 goto done;
 480         }
 481         retval = -EINVAL;
 482         if (b->type != q->type) {
 483                 dprintk(1, "qbuf: Wrong type.\n");
 484                 goto done;
 485         }
 486         if (b->index < 0 || b->index >= VIDEO_MAX_FRAME) {
 487                 dprintk(1, "qbuf: index out of range.\n");
 488                 goto done;
 489         }
 490         buf = q->bufs[b->index];
 491         if (NULL == buf) {
 492                 dprintk(1, "qbuf: buffer is null.\n");
 493                 goto done;
 494         }
 495         MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
 496         if (buf->memory != b->memory) {
 497                 dprintk(1, "qbuf: memory type is wrong.\n");
 498                 goto done;
 499         }
 500         if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
 501                 dprintk(1, "qbuf: buffer is already queued or active.\n");
 502                 goto done;
 503         }
 504
 505         if (b->flags & V4L2_BUF_FLAG_INPUT) {
 506                 if (b->input >= q->inputs) {
 507                         dprintk(1, "qbuf: wrong input.\n");
 508                         goto done;
 509                 }
 510                 buf->input = b->input;
 511         } else {
 512                 buf->input = UNSET;
 513         }
 514
 515         switch (b->memory) {
 516         case V4L2_MEMORY_MMAP:
 517                 if (0 == buf->baddr) {
 518                         dprintk(1, "qbuf: mmap requested "
 519                                    "but buffer addr is zero!\n");
 520                         goto done;
 521                 }
 522                 break;
 523         case V4L2_MEMORY_USERPTR:
 524                 if (b->length < buf->bsize) {
 525                         dprintk(1, "qbuf: buffer length is not enough\n");
 526                         goto done;
 527                 }
 528                 if (VIDEOBUF_NEEDS_INIT != buf->state &&
 529                     buf->baddr != b->m.userptr)
 530                         q->ops->buf_release(q, buf);
 531                 buf->baddr = b->m.userptr;
 532                 break;
 533         case V4L2_MEMORY_OVERLAY:
 534                 buf->boff = b->m.offset;
 535                 break;
 536         default:
 537                 dprintk(1, "qbuf: wrong memory type\n");
 538                 goto done;
 539         }
 540
 541         dprintk(1, "qbuf: requesting next field\n");
 542         field = videobuf_next_field(q);
 543         retval = q->ops->buf_prepare(q, buf, field);
 544         if (0 != retval) {
 545                 dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
 546                 goto done;
 547         }
 548
 549         list_add_tail(&buf->stream, &q->stream);
 550         if (q->streaming) {
 551                 if (q->irqlock)
 552                         spin_lock_irqsave(q->irqlock, flags);
 553                 q->ops->buf_queue(q, buf);
 554                 if (q->irqlock)
 555                         spin_unlock_irqrestore(q->irqlock, flags);
 556         }
 557         dprintk(1, "qbuf: succeded\n");
 558         retval = 0;
 559         wake_up_interruptible_sync(&q->wait);
 560
 561  done:
 562         mutex_unlock(&q->vb_lock);
 563
 564         if (b->memory == V4L2_MEMORY_MMAP)
 565                 up_read(&current->mm->mmap_sem);
 566
 567         return retval;
 568 }
 569
 570
 571 /* Locking: Caller holds q->vb_lock */
 572 static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
 573 {
 574         int retval;
 575
 576 checks:
 577         if (!q->streaming) {
 578                 dprintk(1, "next_buffer: Not streaming\n");
 579                 retval = -EINVAL;
 580                 goto done;
 581         }
 582
 583         if (list_empty(&q->stream)) {
 584                 if (noblock) {
 585                         retval = -EAGAIN;
 586                         dprintk(2, "next_buffer: no buffers to dequeue\n");
 587                         goto done;
 588                 } else {
 589                         dprintk(2, "next_buffer: waiting on buffer\n");
 590
 591                         /* Drop lock to avoid deadlock with qbuf */
 592                         mutex_unlock(&q->vb_lock);
 593
 594                         /* Checking list_empty and streaming is safe without
 595                          * locks because we goto checks to validate while
 596                          * holding locks before proceeding */
 597                         retval = wait_event_interruptible(q->wait,
 598                                 !list_empty(&q->stream) || !q->streaming);
 599                         mutex_lock(&q->vb_lock);
 600
 601                         if (retval)
 602                                 goto done;
 603
 604                         goto checks;
 605                 }
 606         }
 607
 608         retval = 0;
 609
 610 done:
 611         return retval;
 612 }
 613
 614
 615 /* Locking: Caller holds q->vb_lock */
 616 static int stream_next_buffer(struct videobuf_queue *q,
 617                         struct videobuf_buffer **vb, int nonblocking)
 618 {
 619         int retval;
 620         struct videobuf_buffer *buf = NULL;
 621
 622         retval = stream_next_buffer_check_queue(q, nonblocking);
 623         if (retval)
 624                 goto done;
 625
 626         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 627         retval = videobuf_waiton(buf, nonblocking, 1);
 628         if (retval < 0)
 629                 goto done;
 630
 631         *vb = buf;
 632 done:
 633         return retval;
 634 }
 635
 636 int videobuf_dqbuf(struct videobuf_queue *q,
 637                struct v4l2_buffer *b, int nonblocking)
 638 {
 639         struct videobuf_buffer *buf = NULL;
 640         int retval;
 641
 642         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 643
 644         mutex_lock(&q->vb_lock);
 645
 646         retval = stream_next_buffer(q, &buf, nonblocking);
 647         if (retval < 0) {
 648                 dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
 649                 goto done;
 650         }
 651
 652         switch (buf->state) {
 653         case VIDEOBUF_ERROR:
 654                 dprintk(1, "dqbuf: state is error\n");
 655                 retval = -EIO;
 656                 CALL(q, sync, q, buf);
 657                 buf->state = VIDEOBUF_IDLE;
 658                 break;
 659         case VIDEOBUF_DONE:
 660                 dprintk(1, "dqbuf: state is done\n");
 661                 CALL(q, sync, q, buf);
 662                 buf->state = VIDEOBUF_IDLE;
 663                 break;
 664         default:
 665                 dprintk(1, "dqbuf: state invalid\n");
 666                 retval = -EINVAL;
 667                 goto done;
 668         }
 669         list_del(&buf->stream);
 670         memset(b, 0, sizeof(*b));
 671         videobuf_status(q, b, buf, q->type);
 672
 673  done:
 674         mutex_unlock(&q->vb_lock);
 675         return retval;
 676 }
 677
 678 int videobuf_streamon(struct videobuf_queue *q)
 679 {
 680         struct videobuf_buffer *buf;
 681         unsigned long flags = 0;
 682         int retval;
 683
 684         mutex_lock(&q->vb_lock);
 685         retval = -EBUSY;
 686         if (q->reading)
 687                 goto done;
 688         retval = 0;
 689         if (q->streaming)
 690                 goto done;
 691         q->streaming = 1;
 692         if (q->irqlock)
 693                 spin_lock_irqsave(q->irqlock, flags);
 694         list_for_each_entry(buf, &q->stream, stream)
 695                 if (buf->state == VIDEOBUF_PREPARED)
 696                         q->ops->buf_queue(q, buf);
 697         if (q->irqlock)
 698                 spin_unlock_irqrestore(q->irqlock, flags);
 699
 700         wake_up_interruptible_sync(&q->wait);
 701  done:
 702         mutex_unlock(&q->vb_lock);
 703         return retval;
 704 }
 705
 706 /* Locking: Caller holds q->vb_lock */
 707 static int __videobuf_streamoff(struct videobuf_queue *q)
 708 {
 709         if (!q->streaming)
 710                 return -EINVAL;
 711
 712         videobuf_queue_cancel(q);
 713
 714         return 0;
 715 }
 716
 717 int videobuf_streamoff(struct videobuf_queue *q)
 718 {
 719         int retval;
 720
 721         mutex_lock(&q->vb_lock);
 722         retval = __videobuf_streamoff(q);
 723         mutex_unlock(&q->vb_lock);
 724
 725         return retval;
 726 }
 727
 728 /* Locking: Caller holds q->vb_lock */
 729 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
 730                                       char __user *data,
 731                                       size_t count, loff_t *ppos)
 732 {
 733         enum v4l2_field field;
 734         unsigned long flags = 0;
 735         int retval;
 736
 737         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 738
 739         /* setup stuff */
 740         q->read_buf = videobuf_alloc(q);
 741         if (NULL == q->read_buf)
 742                 return -ENOMEM;
 743
 744         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 745         q->read_buf->baddr  = (unsigned long)data;
 746         q->read_buf->bsize  = count;
 747
 748         field = videobuf_next_field(q);
 749         retval = q->ops->buf_prepare(q, q->read_buf, field);
 750         if (0 != retval)
 751                 goto done;
 752
 753         /* start capture & wait */
 754         if (q->irqlock)
 755                 spin_lock_irqsave(q->irqlock, flags);
 756         q->ops->buf_queue(q, q->read_buf);
 757         if (q->irqlock)
 758                 spin_unlock_irqrestore(q->irqlock, flags);
 759         retval = videobuf_waiton(q->read_buf, 0, 0);
 760         if (0 == retval) {
 761                 CALL(q, sync, q, q->read_buf);
 762                 if (VIDEOBUF_ERROR == q->read_buf->state)
 763                         retval = -EIO;
 764                 else
 765                         retval = q->read_buf->size;
 766         }
 767
 768  done:
 769         /* cleanup */
 770         q->ops->buf_release(q, q->read_buf);
 771         kfree(q->read_buf);
 772         q->read_buf = NULL;
 773         return retval;
 774 }
 775
 776 ssize_t videobuf_read_one(struct videobuf_queue *q,
 777                           char __user *data, size_t count, loff_t *ppos,
 778                           int nonblocking)
 779 {
 780         enum v4l2_field field;
 781         unsigned long flags = 0;
 782         unsigned size = 0, nbufs = 1;
 783         int retval;
 784
 785         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 786
 787         mutex_lock(&q->vb_lock);
 788
 789         q->ops->buf_setup(q, &nbufs, &size);
 790
 791         if (NULL == q->read_buf  &&
 792             count >= size        &&
 793             !nonblocking) {
 794                 retval = videobuf_read_zerocopy(q, data, count, ppos);
 795                 if (retval >= 0  ||  retval == -EIO)
 796                         /* ok, all done */
 797                         goto done;
 798                 /* fallback to kernel bounce buffer on failures */
 799         }
 800
 801         if (NULL == q->read_buf) {
 802                 /* need to capture a new frame */
 803                 retval = -ENOMEM;
 804                 q->read_buf = videobuf_alloc(q);
 805
 806                 dprintk(1, "video alloc=0x%p\n", q->read_buf);
 807                 if (NULL == q->read_buf)
 808                         goto done;
 809                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 810                 q->read_buf->bsize = count; /* preferred size */
 811                 field = videobuf_next_field(q);
 812                 retval = q->ops->buf_prepare(q, q->read_buf, field);
 813
 814                 if (0 != retval) {
 815                         kfree(q->read_buf);
 816                         q->read_buf = NULL;
 817                         goto done;
 818                 }
 819                 if (q->irqlock)
 820                         spin_lock_irqsave(q->irqlock, flags);
 821
 822                 q->ops->buf_queue(q, q->read_buf);
 823                 if (q->irqlock)
 824                         spin_unlock_irqrestore(q->irqlock, flags);
 825                 q->read_off = 0;
 826         }
 827
 828         /* wait until capture is done */
 829         retval = videobuf_waiton(q->read_buf, nonblocking, 1);
 830         if (0 != retval)
 831                 goto done;
 832
 833         CALL(q, sync, q, q->read_buf);
 834
 835         if (VIDEOBUF_ERROR == q->read_buf->state) {
 836                 /* catch I/O errors */
 837                 q->ops->buf_release(q, q->read_buf);
 838                 kfree(q->read_buf);
 839                 q->read_buf = NULL;
 840                 retval = -EIO;
 841                 goto done;
 842         }
 843
 844         /* Copy to userspace */
 845         retval = CALL(q, video_copy_to_user, q, data, count, nonblocking);
 846         if (retval < 0)
 847                 goto done;
 848
 849         q->read_off += retval;
 850         if (q->read_off == q->read_buf->size) {
 851                 /* all data copied, cleanup */
 852                 q->ops->buf_release(q, q->read_buf);
 853                 kfree(q->read_buf);
 854                 q->read_buf = NULL;
 855         }
 856
 857  done:
 858         mutex_unlock(&q->vb_lock);
 859         return retval;
 860 }
 861
 862 /* Locking: Caller holds q->vb_lock */
 863 static int __videobuf_read_start(struct videobuf_queue *q)
 864 {
 865         enum v4l2_field field;
 866         unsigned long flags = 0;
 867         unsigned int count = 0, size = 0;
 868         int err, i;
 869
 870         q->ops->buf_setup(q, &count, &size);
 871         if (count < 2)
 872                 count = 2;
 873         if (count > VIDEO_MAX_FRAME)
 874                 count = VIDEO_MAX_FRAME;
 875         size = PAGE_ALIGN(size);
 876
 877         err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
 878         if (err < 0)
 879                 return err;
 880
 881         count = err;
 882
 883         for (i = 0; i < count; i++) {
 884                 field = videobuf_next_field(q);
 885                 err = q->ops->buf_prepare(q, q->bufs[i], field);
 886                 if (err)
 887                         return err;
 888                 list_add_tail(&q->bufs[i]->stream, &q->stream);
 889         }
 890         if (q->irqlock)
 891                 spin_lock_irqsave(q->irqlock, flags);
 892         for (i = 0; i < count; i++)
 893                 q->ops->buf_queue(q, q->bufs[i]);
 894         if (q->irqlock)
 895                 spin_unlock_irqrestore(q->irqlock, flags);
 896         q->reading = 1;
 897         return 0;
 898 }
 899
 900 static void __videobuf_read_stop(struct videobuf_queue *q)
 901 {
 902         int i;
 903
 904         videobuf_queue_cancel(q);
 905         __videobuf_mmap_free(q);
 906         INIT_LIST_HEAD(&q->stream);
 907         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 908                 if (NULL == q->bufs[i])
 909                         continue;
 910                 kfree(q->bufs[i]);
 911                 q->bufs[i] = NULL;
 912         }
 913         q->read_buf = NULL;
 914
 915 }
 916
 917 int videobuf_read_start(struct videobuf_queue *q)
 918 {
 919         int rc;
 920
 921         mutex_lock(&q->vb_lock);
 922         rc = __videobuf_read_start(q);
 923         mutex_unlock(&q->vb_lock);
 924
 925         return rc;
 926 }
 927
 928 void videobuf_read_stop(struct videobuf_queue *q)
 929 {
 930         mutex_lock(&q->vb_lock);
 931         __videobuf_read_stop(q);
 932         mutex_unlock(&q->vb_lock);
 933 }
 934
 935 void videobuf_stop(struct videobuf_queue *q)
 936 {
 937         mutex_lock(&q->vb_lock);
 938
 939         if (q->streaming)
 940                 __videobuf_streamoff(q);
 941
 942         if (q->reading)
 943                 __videobuf_read_stop(q);
 944
 945         mutex_unlock(&q->vb_lock);
 946 }
 947
 948
 949 ssize_t videobuf_read_stream(struct videobuf_queue *q,
 950                              char __user *data, size_t count, loff_t *ppos,
 951                              int vbihack, int nonblocking)
 952 {
 953         int rc, retval;
 954         unsigned long flags = 0;
 955
 956         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 957
 958         dprintk(2, "%s\n", __func__);
 959         mutex_lock(&q->vb_lock);
 960         retval = -EBUSY;
 961         if (q->streaming)
 962                 goto done;
 963         if (!q->reading) {
 964                 retval = __videobuf_read_start(q);
 965                 if (retval < 0)
 966                         goto done;
 967         }
 968
 969         retval = 0;
 970         while (count > 0) {
 971                 /* get / wait for data */
 972                 if (NULL == q->read_buf) {
 973                         q->read_buf = list_entry(q->stream.next,
 974                                                  struct videobuf_buffer,
 975                                                  stream);
 976                         list_del(&q->read_buf->stream);
 977                         q->read_off = 0;
 978                 }
 979                 rc = videobuf_waiton(q->read_buf, nonblocking, 1);
 980                 if (rc < 0) {
 981                         if (0 == retval)
 982                                 retval = rc;
 983                         break;
 984                 }
 985
 986                 if (q->read_buf->state == VIDEOBUF_DONE) {
 987                         rc = CALL(q, copy_stream, q, data + retval, count,
 988                                         retval, vbihack, nonblocking);
 989                         if (rc < 0) {
 990                                 retval = rc;
 991                                 break;
 992                         }
 993                         retval      += rc;
 994                         count       -= rc;
 995                         q->read_off += rc;
 996                 } else {
 997                         /* some error */
 998                         q->read_off = q->read_buf->size;
 999                         if (0 == retval)
1000                                 retval = -EIO;
1001                 }
1002
1003                 /* requeue buffer when done with copying */
1004                 if (q->read_off == q->read_buf->size) {
1005                         list_add_tail(&q->read_buf->stream,
1006                                       &q->stream);
1007                         if (q->irqlock)
1008                                 spin_lock_irqsave(q->irqlock, flags);
1009                         q->ops->buf_queue(q, q->read_buf);
1010                         if (q->irqlock)
1011                                 spin_unlock_irqrestore(q->irqlock, flags);
1012                         q->read_buf = NULL;
1013                 }
1014                 if (retval < 0)
1015                         break;
1016         }
1017
1018  done:
1019         mutex_unlock(&q->vb_lock);
1020         return retval;
1021 }
1022
1023 unsigned int videobuf_poll_stream(struct file *file,
1024                                   struct videobuf_queue *q,
1025                                   poll_table *wait)
1026 {
1027         struct videobuf_buffer *buf = NULL;
1028         unsigned int rc = 0;
1029
1030         mutex_lock(&q->vb_lock);
1031         if (q->streaming) {
1032                 if (!list_empty(&q->stream))
1033                         buf = list_entry(q->stream.next,
1034                                          struct videobuf_buffer, stream);
1035         } else {
1036                 if (!q->reading)
1037                         __videobuf_read_start(q);
1038                 if (!q->reading) {
1039                         rc = POLLERR;
1040                 } else if (NULL == q->read_buf) {
1041                         q->read_buf = list_entry(q->stream.next,
1042                                                  struct videobuf_buffer,
1043                                                  stream);
1044                         list_del(&q->read_buf->stream);
1045                         q->read_off = 0;
1046                 }
1047                 buf = q->read_buf;
1048         }
1049         if (!buf)
1050                 rc = POLLERR;
1051
1052         if (0 == rc) {
1053                 poll_wait(file, &buf->done, wait);
1054                 if (buf->state == VIDEOBUF_DONE ||
1055                     buf->state == VIDEOBUF_ERROR)
1056                         rc = POLLIN|POLLRDNORM;
1057         }
1058         mutex_unlock(&q->vb_lock);
1059         return rc;
1060 }
1061
1062 int videobuf_mmap_mapper(struct videobuf_queue *q,
1063                          struct vm_area_struct *vma)
1064 {
1065         int retval;
1066
1067         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1068
1069         mutex_lock(&q->vb_lock);
1070         retval = CALL(q, mmap_mapper, q, vma);
1071         q->is_mmapped = 1;
1072         mutex_unlock(&q->vb_lock);
1073
1074         return retval;
1075 }
1076
1077 #ifdef CONFIG_VIDEO_V4L1_COMPAT
1078 int videobuf_cgmbuf(struct videobuf_queue *q,
1079                     struct video_mbuf *mbuf, int count)
1080 {
1081         struct v4l2_requestbuffers req;
1082         int rc, i;
1083
1084         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1085
1086         memset(&req, 0, sizeof(req));
1087         req.type   = q->type;
1088         req.count  = count;
1089         req.memory = V4L2_MEMORY_MMAP;
1090         rc = videobuf_reqbufs(q, &req);
1091         if (rc < 0)
1092                 return rc;
1093
1094         mbuf->frames = req.count;
1095         mbuf->size   = 0;
1096         for (i = 0; i < mbuf->frames; i++) {
1097                 mbuf->offsets[i]  = q->bufs[i]->boff;
1098                 mbuf->size       += q->bufs[i]->bsize;
1099         }
1100
1101         return 0;
1102 }
1103 EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
1104 #endif
1105
1106 /* --------------------------------------------------------------------- */
1107
1108 EXPORT_SYMBOL_GPL(videobuf_waiton);
1109 EXPORT_SYMBOL_GPL(videobuf_iolock);
1110
1111 EXPORT_SYMBOL_GPL(videobuf_alloc);
1112
1113 EXPORT_SYMBOL_GPL(videobuf_queue_core_init);
1114 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
1115 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
1116
1117 EXPORT_SYMBOL_GPL(videobuf_next_field);
1118 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
1119 EXPORT_SYMBOL_GPL(videobuf_querybuf);
1120 EXPORT_SYMBOL_GPL(videobuf_qbuf);
1121 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
1122 EXPORT_SYMBOL_GPL(videobuf_streamon);
1123 EXPORT_SYMBOL_GPL(videobuf_streamoff);
1124
1125 EXPORT_SYMBOL_GPL(videobuf_read_start);
1126 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1127 EXPORT_SYMBOL_GPL(videobuf_stop);
1128 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1129 EXPORT_SYMBOL_GPL(videobuf_read_one);
1130 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1131
1132 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
1133 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
1134 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);