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