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