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)  if (unlikely((is) != (should))) \
  26         { printk(KERN_ERR "magic mismatch: %x (expected %x)\n",is,should); BUG(); }
  27
  28 static int debug = 0;
  29 module_param(debug, int, 0644);
  30
  31 MODULE_DESCRIPTION("helper module to manage video4linux buffers");
  32 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
  33 MODULE_LICENSE("GPL");
  34
  35 #define dprintk(level, fmt, arg...)     if (debug >= level) \
  36         printk(KERN_DEBUG "vbuf: " fmt , ## arg)
  37
  38 /* --------------------------------------------------------------------- */
  39
  40 #define CALL(q, f, arg...)                                              \
  41         ( (q->int_ops->f)? q->int_ops->f(arg) : 0)
  42
  43 void* videobuf_alloc(struct videobuf_queue* q)
  44 {
  45         struct videobuf_buffer *vb;
  46
  47         BUG_ON (q->msize<sizeof(*vb));
  48
  49         if (!q->int_ops || !q->int_ops->alloc) {
  50                 printk(KERN_ERR "No specific ops defined!\n");
  51                 BUG();
  52         }
  53
  54         vb = q->int_ops->alloc(q->msize);
  55
  56         if (NULL != vb) {
  57                 init_waitqueue_head(&vb->done);
  58                 vb->magic     = MAGIC_BUFFER;
  59         }
  60
  61         return vb;
  62 }
  63
  64 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
  65 {
  66         int retval = 0;
  67         DECLARE_WAITQUEUE(wait, current);
  68
  69         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
  70         add_wait_queue(&vb->done, &wait);
  71         while (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED) {
  72                 if (non_blocking) {
  73                         retval = -EAGAIN;
  74                         break;
  75                 }
  76                 set_current_state(intr  ? TASK_INTERRUPTIBLE
  77                                         : TASK_UNINTERRUPTIBLE);
  78                 if (vb->state == STATE_ACTIVE || vb->state == STATE_QUEUED)
  79                         schedule();
  80                 set_current_state(TASK_RUNNING);
  81                 if (intr && signal_pending(current)) {
  82                         dprintk(1,"buffer waiton: -EINTR\n");
  83                         retval = -EINTR;
  84                         break;
  85                 }
  86         }
  87         remove_wait_queue(&vb->done, &wait);
  88         return retval;
  89 }
  90
  91 int videobuf_iolock(struct videobuf_queue* q, struct videobuf_buffer *vb,
  92                     struct v4l2_framebuffer *fbuf)
  93 {
  94         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
  95         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
  96
  97         return CALL(q,iolock,q,vb,fbuf);
  98 }
  99
 100 /* --------------------------------------------------------------------- */
 101
 102
 103 void videobuf_queue_init(struct videobuf_queue* q,
 104                          struct videobuf_queue_ops *ops,
 105                          void *dev,
 106                          spinlock_t *irqlock,
 107                          enum v4l2_buf_type type,
 108                          enum v4l2_field field,
 109                          unsigned int msize,
 110                          void *priv)
 111 {
 112         memset(q,0,sizeof(*q));
 113         q->irqlock = irqlock;
 114         q->dev     = dev;
 115         q->type    = type;
 116         q->field   = field;
 117         q->msize   = msize;
 118         q->ops     = ops;
 119         q->priv_data = priv;
 120
 121         /* All buffer operations are mandatory */
 122         BUG_ON (!q->ops->buf_setup);
 123         BUG_ON (!q->ops->buf_prepare);
 124         BUG_ON (!q->ops->buf_queue);
 125         BUG_ON (!q->ops->buf_release);
 126
 127         mutex_init(&q->lock);
 128         INIT_LIST_HEAD(&q->stream);
 129 }
 130
 131 int videobuf_queue_is_busy(struct videobuf_queue *q)
 132 {
 133         int i;
 134
 135         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 136
 137         if (q->streaming) {
 138                 dprintk(1,"busy: streaming active\n");
 139                 return 1;
 140         }
 141         if (q->reading) {
 142                 dprintk(1,"busy: pending read #1\n");
 143                 return 1;
 144         }
 145         if (q->read_buf) {
 146                 dprintk(1,"busy: pending read #2\n");
 147                 return 1;
 148         }
 149         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 150                 if (NULL == q->bufs[i])
 151                         continue;
 152                 if (q->bufs[i]->map) {
 153                         dprintk(1,"busy: buffer #%d mapped\n",i);
 154                         return 1;
 155                 }
 156                 if (q->bufs[i]->state == STATE_QUEUED) {
 157                         dprintk(1,"busy: buffer #%d queued\n",i);
 158                         return 1;
 159                 }
 160                 if (q->bufs[i]->state == STATE_ACTIVE) {
 161                         dprintk(1,"busy: buffer #%d avtive\n",i);
 162                         return 1;
 163                 }
 164         }
 165         return 0;
 166 }
 167
 168 void videobuf_queue_cancel(struct videobuf_queue *q)
 169 {
 170         unsigned long flags=0;
 171         int i;
 172
 173         /* remove queued buffers from list */
 174         if (q->irqlock)
 175                 spin_lock_irqsave(q->irqlock,flags);
 176         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 177                 if (NULL == q->bufs[i])
 178                         continue;
 179                 if (q->bufs[i]->state == STATE_QUEUED) {
 180                         list_del(&q->bufs[i]->queue);
 181                         q->bufs[i]->state = STATE_ERROR;
 182                 }
 183         }
 184         if (q->irqlock)
 185                 spin_unlock_irqrestore(q->irqlock,flags);
 186
 187         /* free all buffers + clear queue */
 188         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 189                 if (NULL == q->bufs[i])
 190                         continue;
 191                 q->ops->buf_release(q,q->bufs[i]);
 192         }
 193         INIT_LIST_HEAD(&q->stream);
 194 }
 195
 196 /* --------------------------------------------------------------------- */
 197
 198 enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
 199 {
 200         enum v4l2_field field = q->field;
 201
 202         BUG_ON(V4L2_FIELD_ANY == field);
 203
 204         if (V4L2_FIELD_ALTERNATE == field) {
 205                 if (V4L2_FIELD_TOP == q->last) {
 206                         field   = V4L2_FIELD_BOTTOM;
 207                         q->last = V4L2_FIELD_BOTTOM;
 208                 } else {
 209                         field   = V4L2_FIELD_TOP;
 210                         q->last = V4L2_FIELD_TOP;
 211                 }
 212         }
 213         return field;
 214 }
 215
 216 static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
 217                             struct videobuf_buffer *vb, enum v4l2_buf_type type)
 218 {
 219         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
 220         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 221
 222         b->index    = vb->i;
 223         b->type     = type;
 224
 225         b->memory   = vb->memory;
 226         switch (b->memory) {
 227         case V4L2_MEMORY_MMAP:
 228                 b->m.offset  = vb->boff;
 229                 b->length    = vb->bsize;
 230                 break;
 231         case V4L2_MEMORY_USERPTR:
 232                 b->m.userptr = vb->baddr;
 233                 b->length    = vb->bsize;
 234                 break;
 235         case V4L2_MEMORY_OVERLAY:
 236                 b->m.offset  = vb->boff;
 237                 break;
 238         }
 239
 240         b->flags    = 0;
 241         if (vb->map)
 242                 b->flags |= V4L2_BUF_FLAG_MAPPED;
 243
 244         switch (vb->state) {
 245         case STATE_PREPARED:
 246         case STATE_QUEUED:
 247         case STATE_ACTIVE:
 248                 b->flags |= V4L2_BUF_FLAG_QUEUED;
 249                 break;
 250         case STATE_DONE:
 251         case STATE_ERROR:
 252                 b->flags |= V4L2_BUF_FLAG_DONE;
 253                 break;
 254         case STATE_NEEDS_INIT:
 255         case STATE_IDLE:
 256                 /* nothing */
 257                 break;
 258         }
 259
 260         if (vb->input != UNSET) {
 261                 b->flags |= V4L2_BUF_FLAG_INPUT;
 262                 b->input  = vb->input;
 263         }
 264
 265         b->field     = vb->field;
 266         b->timestamp = vb->ts;
 267         b->bytesused = vb->size;
 268         b->sequence  = vb->field_count >> 1;
 269 }
 270
 271 int videobuf_reqbufs(struct videobuf_queue *q,
 272                  struct v4l2_requestbuffers *req)
 273 {
 274         unsigned int size,count;
 275         int retval;
 276
 277         if (req->type != q->type) {
 278                 dprintk(1,"reqbufs: queue type invalid\n");
 279                 return -EINVAL;
 280         }
 281         if (req->count < 1) {
 282                 dprintk(1,"reqbufs: count invalid (%d)\n",req->count);
 283                 return -EINVAL;
 284         }
 285         if (req->memory != V4L2_MEMORY_MMAP     &&
 286             req->memory != V4L2_MEMORY_USERPTR  &&
 287             req->memory != V4L2_MEMORY_OVERLAY) {
 288                 dprintk(1,"reqbufs: memory type invalid\n");
 289                 return -EINVAL;
 290         }
 291
 292         mutex_lock(&q->lock);
 293         if (q->streaming) {
 294                 dprintk(1,"reqbufs: streaming already exists\n");
 295                 retval = -EBUSY;
 296                 goto done;
 297         }
 298         if (!list_empty(&q->stream)) {
 299                 dprintk(1,"reqbufs: stream running\n");
 300                 retval = -EBUSY;
 301                 goto done;
 302         }
 303
 304         count = req->count;
 305         if (count > VIDEO_MAX_FRAME)
 306                 count = VIDEO_MAX_FRAME;
 307         size = 0;
 308         q->ops->buf_setup(q,&count,&size);
 309         size = PAGE_ALIGN(size);
 310         dprintk(1,"reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
 311                 count, size, (count*size)>>PAGE_SHIFT);
 312
 313         retval = videobuf_mmap_setup(q,count,size,req->memory);
 314         if (retval < 0) {
 315                 dprintk(1,"reqbufs: mmap setup returned %d\n",retval);
 316                 goto done;
 317         }
 318
 319         req->count = count;
 320
 321  done:
 322         mutex_unlock(&q->lock);
 323         return retval;
 324 }
 325
 326 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 327 {
 328         if (unlikely(b->type != q->type)) {
 329                 dprintk(1,"querybuf: Wrong type.\n");
 330                 return -EINVAL;
 331         }
 332         if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME)) {
 333                 dprintk(1,"querybuf: index out of range.\n");
 334                 return -EINVAL;
 335         }
 336         if (unlikely(NULL == q->bufs[b->index])) {
 337                 dprintk(1,"querybuf: buffer is null.\n");
 338                 return -EINVAL;
 339         }
 340         videobuf_status(q,b,q->bufs[b->index],q->type);
 341         return 0;
 342 }
 343
 344 int videobuf_qbuf(struct videobuf_queue *q,
 345               struct v4l2_buffer *b)
 346 {
 347         struct videobuf_buffer *buf;
 348         enum v4l2_field field;
 349         unsigned long flags=0;
 350         int retval;
 351
 352         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 353
 354         if (b->memory == V4L2_MEMORY_MMAP)
 355                 down_read(&current->mm->mmap_sem);
 356
 357         mutex_lock(&q->lock);
 358         retval = -EBUSY;
 359         if (q->reading) {
 360                 dprintk(1,"qbuf: Reading running...\n");
 361                 goto done;
 362         }
 363         retval = -EINVAL;
 364         if (b->type != q->type) {
 365                 dprintk(1,"qbuf: Wrong type.\n");
 366                 goto done;
 367         }
 368         if (b->index < 0 || b->index >= VIDEO_MAX_FRAME) {
 369                 dprintk(1,"qbuf: index out of range.\n");
 370                 goto done;
 371         }
 372         buf = q->bufs[b->index];
 373         if (NULL == buf) {
 374                 dprintk(1,"qbuf: buffer is null.\n");
 375                 goto done;
 376         }
 377         MAGIC_CHECK(buf->magic,MAGIC_BUFFER);
 378         if (buf->memory != b->memory) {
 379                 dprintk(1,"qbuf: memory type is wrong.\n");
 380                 goto done;
 381         }
 382         if (buf->state != STATE_NEEDS_INIT && buf->state != STATE_IDLE) {
 383                 dprintk(1,"qbuf: buffer is already queued or active.\n");
 384                 goto done;
 385         }
 386
 387         if (b->flags & V4L2_BUF_FLAG_INPUT) {
 388                 if (b->input >= q->inputs) {
 389                         dprintk(1,"qbuf: wrong input.\n");
 390                         goto done;
 391                 }
 392                 buf->input = b->input;
 393         } else {
 394                 buf->input = UNSET;
 395         }
 396
 397         switch (b->memory) {
 398         case V4L2_MEMORY_MMAP:
 399                 if (0 == buf->baddr) {
 400                         dprintk(1,"qbuf: mmap requested but buffer addr is zero!\n");
 401                         goto done;
 402                 }
 403                 break;
 404         case V4L2_MEMORY_USERPTR:
 405                 if (b->length < buf->bsize) {
 406                         dprintk(1,"qbuf: buffer length is not enough\n");
 407                         goto done;
 408                 }
 409                 if (STATE_NEEDS_INIT != buf->state && buf->baddr != b->m.userptr)
 410                         q->ops->buf_release(q,buf);
 411                 buf->baddr = b->m.userptr;
 412                 break;
 413         case V4L2_MEMORY_OVERLAY:
 414                 buf->boff = b->m.offset;
 415                 break;
 416         default:
 417                 dprintk(1,"qbuf: wrong memory type\n");
 418                 goto done;
 419         }
 420
 421         dprintk(1,"qbuf: requesting next field\n");
 422         field = videobuf_next_field(q);
 423         retval = q->ops->buf_prepare(q,buf,field);
 424         if (0 != retval) {
 425                 dprintk(1,"qbuf: buffer_prepare returned %d\n",retval);
 426                 goto done;
 427         }
 428
 429         list_add_tail(&buf->stream,&q->stream);
 430         if (q->streaming) {
 431                 if (q->irqlock)
 432                         spin_lock_irqsave(q->irqlock,flags);
 433                 q->ops->buf_queue(q,buf);
 434                 if (q->irqlock)
 435                         spin_unlock_irqrestore(q->irqlock,flags);
 436         }
 437         dprintk(1,"qbuf: succeded\n");
 438         retval = 0;
 439
 440  done:
 441         mutex_unlock(&q->lock);
 442
 443         if (b->memory == V4L2_MEMORY_MMAP)
 444                 up_read(&current->mm->mmap_sem);
 445
 446         return retval;
 447 }
 448
 449 int videobuf_dqbuf(struct videobuf_queue *q,
 450                struct v4l2_buffer *b, int nonblocking)
 451 {
 452         struct videobuf_buffer *buf;
 453         int retval;
 454
 455         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 456
 457         mutex_lock(&q->lock);
 458         retval = -EBUSY;
 459         if (q->reading) {
 460                 dprintk(1,"dqbuf: Reading running...\n");
 461                 goto done;
 462         }
 463         retval = -EINVAL;
 464         if (b->type != q->type) {
 465                 dprintk(1,"dqbuf: Wrong type.\n");
 466                 goto done;
 467         }
 468         if (list_empty(&q->stream)) {
 469                 dprintk(1,"dqbuf: stream running\n");
 470                 goto done;
 471         }
 472         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 473         retval = videobuf_waiton(buf, nonblocking, 1);
 474         if (retval < 0) {
 475                 dprintk(1,"dqbuf: waiton returned %d\n",retval);
 476                 goto done;
 477         }
 478         switch (buf->state) {
 479         case STATE_ERROR:
 480                 dprintk(1,"dqbuf: state is error\n");
 481                 retval = -EIO;
 482                 CALL(q,sync,q, buf);
 483                 buf->state = STATE_IDLE;
 484                 break;
 485         case STATE_DONE:
 486                 dprintk(1,"dqbuf: state is done\n");
 487                 CALL(q,sync,q, buf);
 488                 buf->state = STATE_IDLE;
 489                 break;
 490         default:
 491                 dprintk(1,"dqbuf: state invalid\n");
 492                 retval = -EINVAL;
 493                 goto done;
 494         }
 495         list_del(&buf->stream);
 496         memset(b,0,sizeof(*b));
 497         videobuf_status(q,b,buf,q->type);
 498
 499  done:
 500         mutex_unlock(&q->lock);
 501         return retval;
 502 }
 503
 504 int videobuf_streamon(struct videobuf_queue *q)
 505 {
 506         struct videobuf_buffer *buf;
 507         struct list_head *list;
 508         unsigned long flags=0;
 509         int retval;
 510
 511         mutex_lock(&q->lock);
 512         retval = -EBUSY;
 513         if (q->reading)
 514                 goto done;
 515         retval = 0;
 516         if (q->streaming)
 517                 goto done;
 518         q->streaming = 1;
 519         if (q->irqlock)
 520                 spin_lock_irqsave(q->irqlock,flags);
 521         list_for_each(list,&q->stream) {
 522                 buf = list_entry(list, struct videobuf_buffer, stream);
 523                 if (buf->state == STATE_PREPARED)
 524                         q->ops->buf_queue(q,buf);
 525         }
 526         if (q->irqlock)
 527                 spin_unlock_irqrestore(q->irqlock,flags);
 528
 529  done:
 530         mutex_unlock(&q->lock);
 531         return retval;
 532 }
 533
 534 int videobuf_streamoff(struct videobuf_queue *q)
 535 {
 536         int retval = -EINVAL;
 537
 538         mutex_lock(&q->lock);
 539         if (!q->streaming)
 540                 goto done;
 541         videobuf_queue_cancel(q);
 542         q->streaming = 0;
 543         retval = 0;
 544
 545  done:
 546         mutex_unlock(&q->lock);
 547         return retval;
 548 }
 549
 550 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
 551                                       char __user *data,
 552                                       size_t count, loff_t *ppos)
 553 {
 554         enum v4l2_field field;
 555         unsigned long flags=0;
 556         int retval;
 557
 558         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 559
 560         /* setup stuff */
 561         q->read_buf = videobuf_alloc(q);
 562         if (NULL == q->read_buf)
 563                 return -ENOMEM;
 564
 565         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 566         q->read_buf->baddr  = (unsigned long)data;
 567         q->read_buf->bsize  = count;
 568
 569         field = videobuf_next_field(q);
 570         retval = q->ops->buf_prepare(q,q->read_buf,field);
 571         if (0 != retval)
 572                 goto done;
 573
 574         /* start capture & wait */
 575         if (q->irqlock)
 576                 spin_lock_irqsave(q->irqlock,flags);
 577         q->ops->buf_queue(q,q->read_buf);
 578         if (q->irqlock)
 579                 spin_unlock_irqrestore(q->irqlock,flags);
 580         retval = videobuf_waiton(q->read_buf,0,0);
 581         if (0 == retval) {
 582                 CALL(q,sync,q,q->read_buf);
 583                 if (STATE_ERROR == q->read_buf->state)
 584                         retval = -EIO;
 585                 else
 586                         retval = q->read_buf->size;
 587         }
 588
 589  done:
 590         /* cleanup */
 591         q->ops->buf_release(q,q->read_buf);
 592         kfree(q->read_buf);
 593         q->read_buf = NULL;
 594         return retval;
 595 }
 596
 597 ssize_t videobuf_read_one(struct videobuf_queue *q,
 598                           char __user *data, size_t count, loff_t *ppos,
 599                           int nonblocking)
 600 {
 601         enum v4l2_field field;
 602         unsigned long flags=0;
 603         unsigned size, nbufs;
 604         int retval;
 605
 606         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 607
 608         mutex_lock(&q->lock);
 609
 610         nbufs = 1; size = 0;
 611         q->ops->buf_setup(q,&nbufs,&size);
 612
 613         if (NULL == q->read_buf  &&
 614             count >= size        &&
 615             !nonblocking) {
 616                 retval = videobuf_read_zerocopy(q,data,count,ppos);
 617                 if (retval >= 0  ||  retval == -EIO)
 618                         /* ok, all done */
 619                         goto done;
 620                 /* fallback to kernel bounce buffer on failures */
 621         }
 622
 623         if (NULL == q->read_buf) {
 624                 /* need to capture a new frame */
 625                 retval = -ENOMEM;
 626                 q->read_buf = videobuf_alloc(q);
 627
 628                 dprintk(1,"video alloc=0x%p\n", q->read_buf);
 629                 if (NULL == q->read_buf)
 630                         goto done;
 631                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 632                 q->read_buf->bsize = count; /* preferred size */
 633                 field = videobuf_next_field(q);
 634                 retval = q->ops->buf_prepare(q,q->read_buf,field);
 635
 636                 if (0 != retval) {
 637                         kfree (q->read_buf);
 638                         q->read_buf = NULL;
 639                         goto done;
 640                 }
 641                 if (q->irqlock)
 642                         spin_lock_irqsave(q->irqlock,flags);
 643
 644                 q->ops->buf_queue(q,q->read_buf);
 645                 if (q->irqlock)
 646                         spin_unlock_irqrestore(q->irqlock,flags);
 647                 q->read_off = 0;
 648         }
 649
 650         /* wait until capture is done */
 651         retval = videobuf_waiton(q->read_buf, nonblocking, 1);
 652         if (0 != retval)
 653                 goto done;
 654
 655         CALL(q,sync,q,q->read_buf);
 656
 657         if (STATE_ERROR == q->read_buf->state) {
 658                 /* catch I/O errors */
 659                 q->ops->buf_release(q,q->read_buf);
 660                 kfree(q->read_buf);
 661                 q->read_buf = NULL;
 662                 retval = -EIO;
 663                 goto done;
 664         }
 665
 666         /* Copy to userspace */
 667         retval=CALL(q,copy_to_user,q,data,count,nonblocking);
 668         if (retval<0)
 669                 goto done;
 670
 671         q->read_off += retval;
 672         if (q->read_off == q->read_buf->size) {
 673                 /* all data copied, cleanup */
 674                 q->ops->buf_release(q,q->read_buf);
 675                 kfree(q->read_buf);
 676                 q->read_buf = NULL;
 677         }
 678
 679  done:
 680         mutex_unlock(&q->lock);
 681         return retval;
 682 }
 683
 684 int videobuf_read_start(struct videobuf_queue *q)
 685 {
 686         enum v4l2_field field;
 687         unsigned long flags=0;
 688         int count = 0, size = 0;
 689         int err, i;
 690
 691         q->ops->buf_setup(q,&count,&size);
 692         if (count < 2)
 693                 count = 2;
 694         if (count > VIDEO_MAX_FRAME)
 695                 count = VIDEO_MAX_FRAME;
 696         size = PAGE_ALIGN(size);
 697
 698         err = videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
 699         if (err)
 700                 return err;
 701
 702         for (i = 0; i < count; i++) {
 703                 field = videobuf_next_field(q);
 704                 err = q->ops->buf_prepare(q,q->bufs[i],field);
 705                 if (err)
 706                         return err;
 707                 list_add_tail(&q->bufs[i]->stream, &q->stream);
 708         }
 709         if (q->irqlock)
 710                 spin_lock_irqsave(q->irqlock,flags);
 711         for (i = 0; i < count; i++)
 712                 q->ops->buf_queue(q,q->bufs[i]);
 713         if (q->irqlock)
 714                 spin_unlock_irqrestore(q->irqlock,flags);
 715         q->reading = 1;
 716         return 0;
 717 }
 718
 719 void videobuf_read_stop(struct videobuf_queue *q)
 720 {
 721         int i;
 722
 723         videobuf_queue_cancel(q);
 724         videobuf_mmap_free(q);
 725         INIT_LIST_HEAD(&q->stream);
 726         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 727                 if (NULL == q->bufs[i])
 728                         continue;
 729                 kfree(q->bufs[i]);
 730                 q->bufs[i] = NULL;
 731         }
 732         q->read_buf = NULL;
 733         q->reading  = 0;
 734 }
 735
 736 ssize_t videobuf_read_stream(struct videobuf_queue *q,
 737                              char __user *data, size_t count, loff_t *ppos,
 738                              int vbihack, int nonblocking)
 739 {
 740         int rc, retval;
 741         unsigned long flags=0;
 742
 743         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 744
 745         dprintk(2,"%s\n",__FUNCTION__);
 746         mutex_lock(&q->lock);
 747         retval = -EBUSY;
 748         if (q->streaming)
 749                 goto done;
 750         if (!q->reading) {
 751                 retval = videobuf_read_start(q);
 752                 if (retval < 0)
 753                         goto done;
 754         }
 755
 756         retval = 0;
 757         while (count > 0) {
 758                 /* get / wait for data */
 759                 if (NULL == q->read_buf) {
 760                         q->read_buf = list_entry(q->stream.next,
 761                                                  struct videobuf_buffer,
 762                                                  stream);
 763                         list_del(&q->read_buf->stream);
 764                         q->read_off = 0;
 765                 }
 766                 rc = videobuf_waiton(q->read_buf, nonblocking, 1);
 767                 if (rc < 0) {
 768                         if (0 == retval)
 769                                 retval = rc;
 770                         break;
 771                 }
 772
 773                 if (q->read_buf->state == STATE_DONE) {
 774                         rc = CALL (q,copy_stream, q, data, count,
 775                                         retval, vbihack, nonblocking);
 776                         if (rc < 0) {
 777                                 retval = rc;
 778                                 break;
 779                         }
 780                         retval      += rc;
 781                         count       -= rc;
 782                         q->read_off += rc;
 783                 } else {
 784                         /* some error */
 785                         q->read_off = q->read_buf->size;
 786                         if (0 == retval)
 787                                 retval = -EIO;
 788                 }
 789
 790                 /* requeue buffer when done with copying */
 791                 if (q->read_off == q->read_buf->size) {
 792                         list_add_tail(&q->read_buf->stream,
 793                                       &q->stream);
 794                         if (q->irqlock)
 795                                 spin_lock_irqsave(q->irqlock,flags);
 796                         q->ops->buf_queue(q,q->read_buf);
 797                         if (q->irqlock)
 798                                 spin_unlock_irqrestore(q->irqlock,flags);
 799                         q->read_buf = NULL;
 800                 }
 801                 if (retval < 0)
 802                         break;
 803         }
 804
 805  done:
 806         mutex_unlock(&q->lock);
 807         return retval;
 808 }
 809
 810 unsigned int videobuf_poll_stream(struct file *file,
 811                                   struct videobuf_queue *q,
 812                                   poll_table *wait)
 813 {
 814         struct videobuf_buffer *buf = NULL;
 815         unsigned int rc = 0;
 816
 817         mutex_lock(&q->lock);
 818         if (q->streaming) {
 819                 if (!list_empty(&q->stream))
 820                         buf = list_entry(q->stream.next,
 821                                          struct videobuf_buffer, stream);
 822         } else {
 823                 if (!q->reading)
 824                         videobuf_read_start(q);
 825                 if (!q->reading) {
 826                         rc = POLLERR;
 827                 } else if (NULL == q->read_buf) {
 828                         q->read_buf = list_entry(q->stream.next,
 829                                                  struct videobuf_buffer,
 830                                                  stream);
 831                         list_del(&q->read_buf->stream);
 832                         q->read_off = 0;
 833                 }
 834                 buf = q->read_buf;
 835         }
 836         if (!buf)
 837                 rc = POLLERR;
 838
 839         if (0 == rc) {
 840                 poll_wait(file, &buf->done, wait);
 841                 if (buf->state == STATE_DONE ||
 842                     buf->state == STATE_ERROR)
 843                         rc = POLLIN|POLLRDNORM;
 844         }
 845         mutex_unlock(&q->lock);
 846         return rc;
 847 }
 848
 849 int videobuf_mmap_setup(struct videobuf_queue *q,
 850                         unsigned int bcount, unsigned int bsize,
 851                         enum v4l2_memory memory)
 852 {
 853         unsigned int i;
 854         int err;
 855
 856         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 857
 858         err = videobuf_mmap_free(q);
 859         if (0 != err)
 860                 return err;
 861
 862         /* Allocate and initialize buffers */
 863         for (i = 0; i < bcount; i++) {
 864                 q->bufs[i] = videobuf_alloc(q);
 865
 866                 q->bufs[i]->i      = i;
 867                 q->bufs[i]->input  = UNSET;
 868                 q->bufs[i]->memory = memory;
 869                 q->bufs[i]->bsize  = bsize;
 870                 switch (memory) {
 871                 case V4L2_MEMORY_MMAP:
 872                         q->bufs[i]->boff  = bsize * i;
 873                         break;
 874                 case V4L2_MEMORY_USERPTR:
 875                 case V4L2_MEMORY_OVERLAY:
 876                         /* nothing */
 877                         break;
 878                 }
 879         }
 880
 881         dprintk(1,"mmap setup: %d buffers, %d bytes each\n",
 882                 bcount,bsize);
 883
 884         return 0;
 885 }
 886
 887 int videobuf_mmap_free(struct videobuf_queue *q)
 888 {
 889         int i;
 890         int rc;
 891
 892         if (!q)
 893                 return 0;
 894
 895         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 896
 897         rc  = CALL(q,mmap_free,q);
 898         if (rc<0)
 899                 return rc;
 900
 901         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 902                 if (NULL == q->bufs[i])
 903                         continue;
 904                 q->ops->buf_release(q,q->bufs[i]);
 905                 kfree(q->bufs[i]);
 906                 q->bufs[i] = NULL;
 907         }
 908
 909         return rc;
 910 }
 911
 912 int videobuf_mmap_mapper(struct videobuf_queue *q,
 913                          struct vm_area_struct *vma)
 914 {
 915         int retval;
 916
 917         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 918
 919         mutex_lock(&q->lock);
 920         retval=CALL(q,mmap_mapper,q,vma);
 921         mutex_unlock(&q->lock);
 922
 923         return retval;
 924 }
 925
 926 #ifdef CONFIG_VIDEO_V4L1_COMPAT
 927 int videobuf_cgmbuf(struct videobuf_queue *q,
 928                     struct video_mbuf *mbuf, int count)
 929 {
 930         struct v4l2_requestbuffers req;
 931         int rc,i;
 932
 933         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 934
 935         memset(&req,0,sizeof(req));
 936         req.type   = q->type;
 937         req.count  = count;
 938         req.memory = V4L2_MEMORY_MMAP;
 939         rc = videobuf_reqbufs(q,&req);
 940         if (rc < 0)
 941                 return rc;
 942
 943         mbuf->frames = req.count;
 944         mbuf->size   = 0;
 945         for (i = 0; i < mbuf->frames; i++) {
 946                 mbuf->offsets[i]  = q->bufs[i]->boff;
 947                 mbuf->size       += q->bufs[i]->bsize;
 948         }
 949
 950         return 0;
 951 }
 952 #endif
 953
 954 /* --------------------------------------------------------------------- */
 955
 956 EXPORT_SYMBOL_GPL(videobuf_waiton);
 957 EXPORT_SYMBOL_GPL(videobuf_iolock);
 958
 959 EXPORT_SYMBOL_GPL(videobuf_alloc);
 960
 961 EXPORT_SYMBOL_GPL(videobuf_queue_init);
 962 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
 963 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
 964
 965 EXPORT_SYMBOL_GPL(videobuf_next_field);
 966 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
 967 EXPORT_SYMBOL_GPL(videobuf_querybuf);
 968 EXPORT_SYMBOL_GPL(videobuf_qbuf);
 969 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
 970 EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
 971 EXPORT_SYMBOL_GPL(videobuf_streamon);
 972 EXPORT_SYMBOL_GPL(videobuf_streamoff);
 973
 974 EXPORT_SYMBOL_GPL(videobuf_read_start);
 975 EXPORT_SYMBOL_GPL(videobuf_read_stop);
 976 EXPORT_SYMBOL_GPL(videobuf_read_stream);
 977 EXPORT_SYMBOL_GPL(videobuf_read_one);
 978 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
 979
 980 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
 981 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
 982 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
 983
 984 /*
 985  * Local variables:
 986  * c-basic-offset: 8
 987  * End:
 988  */