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 (CALL(q,is_mmapped,q->bufs[i])) {
 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 (CALL(q,is_mmapped,vb))
 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         if (q->streaming) {
 293                 dprintk(1,"reqbufs: streaming already exists\n");
 294                 return -EBUSY;
 295         }
 296         if (!list_empty(&q->stream)) {
 297                 dprintk(1,"reqbufs: stream running\n");
 298                 return -EBUSY;
 299         }
 300
 301         mutex_lock(&q->lock);
 302         count = req->count;
 303         if (count > VIDEO_MAX_FRAME)
 304                 count = VIDEO_MAX_FRAME;
 305         size = 0;
 306         q->ops->buf_setup(q,&count,&size);
 307         size = PAGE_ALIGN(size);
 308         dprintk(1,"reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
 309                 count, size, (count*size)>>PAGE_SHIFT);
 310
 311         retval = videobuf_mmap_setup(q,count,size,req->memory);
 312         if (retval < 0) {
 313                 dprintk(1,"reqbufs: mmap setup returned %d\n",retval);
 314                 goto done;
 315         }
 316
 317         req->count = count;
 318
 319  done:
 320         mutex_unlock(&q->lock);
 321         return retval;
 322 }
 323
 324 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 325 {
 326         if (unlikely(b->type != q->type)) {
 327                 dprintk(1,"querybuf: Wrong type.\n");
 328                 return -EINVAL;
 329         }
 330         if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME)) {
 331                 dprintk(1,"querybuf: index out of range.\n");
 332                 return -EINVAL;
 333         }
 334         if (unlikely(NULL == q->bufs[b->index])) {
 335                 dprintk(1,"querybuf: buffer is null.\n");
 336                 return -EINVAL;
 337         }
 338         videobuf_status(q,b,q->bufs[b->index],q->type);
 339         return 0;
 340 }
 341
 342 int videobuf_qbuf(struct videobuf_queue *q,
 343               struct v4l2_buffer *b)
 344 {
 345         struct videobuf_buffer *buf;
 346         enum v4l2_field field;
 347         unsigned long flags=0;
 348         int retval;
 349
 350         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 351
 352         mutex_lock(&q->lock);
 353         retval = -EBUSY;
 354         if (q->reading) {
 355                 dprintk(1,"qbuf: Reading running...\n");
 356                 goto done;
 357         }
 358         retval = -EINVAL;
 359         if (b->type != q->type) {
 360                 dprintk(1,"qbuf: Wrong type.\n");
 361                 goto done;
 362         }
 363         if (b->index < 0 || b->index >= VIDEO_MAX_FRAME) {
 364                 dprintk(1,"qbuf: index out of range.\n");
 365                 goto done;
 366         }
 367         buf = q->bufs[b->index];
 368         if (NULL == buf) {
 369                 dprintk(1,"qbuf: buffer is null.\n");
 370                 goto done;
 371         }
 372         MAGIC_CHECK(buf->magic,MAGIC_BUFFER);
 373         if (buf->memory != b->memory) {
 374                 dprintk(1,"qbuf: memory type is wrong.\n");
 375                 goto done;
 376         }
 377         if (buf->state != STATE_NEEDS_INIT && buf->state != STATE_IDLE) {
 378                 dprintk(1,"qbuf: buffer is already queued or active.\n");
 379                 goto done;
 380         }
 381
 382         if (b->flags & V4L2_BUF_FLAG_INPUT) {
 383                 if (b->input >= q->inputs) {
 384                         dprintk(1,"qbuf: wrong input.\n");
 385                         goto done;
 386                 }
 387                 buf->input = b->input;
 388         } else {
 389                 buf->input = UNSET;
 390         }
 391
 392         switch (b->memory) {
 393         case V4L2_MEMORY_MMAP:
 394                 if (0 == buf->baddr) {
 395                         dprintk(1,"qbuf: mmap requested but buffer addr is zero!\n");
 396                         goto done;
 397                 }
 398                 break;
 399         case V4L2_MEMORY_USERPTR:
 400                 if (b->length < buf->bsize) {
 401                         dprintk(1,"qbuf: buffer length is not enough\n");
 402                         goto done;
 403                 }
 404                 if (STATE_NEEDS_INIT != buf->state && buf->baddr != b->m.userptr)
 405                         q->ops->buf_release(q,buf);
 406                 buf->baddr = b->m.userptr;
 407                 break;
 408         case V4L2_MEMORY_OVERLAY:
 409                 buf->boff = b->m.offset;
 410                 break;
 411         default:
 412                 dprintk(1,"qbuf: wrong memory type\n");
 413                 goto done;
 414         }
 415
 416         dprintk(1,"qbuf: requesting next field\n");
 417         field = videobuf_next_field(q);
 418         retval = q->ops->buf_prepare(q,buf,field);
 419         if (0 != retval) {
 420                 dprintk(1,"qbuf: buffer_prepare returned %d\n",retval);
 421                 goto done;
 422         }
 423
 424         list_add_tail(&buf->stream,&q->stream);
 425         if (q->streaming) {
 426                 if (q->irqlock)
 427                         spin_lock_irqsave(q->irqlock,flags);
 428                 q->ops->buf_queue(q,buf);
 429                 if (q->irqlock)
 430                         spin_unlock_irqrestore(q->irqlock,flags);
 431         }
 432         dprintk(1,"qbuf: succeded\n");
 433         retval = 0;
 434
 435  done:
 436         mutex_unlock(&q->lock);
 437         return retval;
 438 }
 439
 440 int videobuf_dqbuf(struct videobuf_queue *q,
 441                struct v4l2_buffer *b, int nonblocking)
 442 {
 443         struct videobuf_buffer *buf;
 444         int retval;
 445
 446         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 447
 448         mutex_lock(&q->lock);
 449         retval = -EBUSY;
 450         if (q->reading) {
 451                 dprintk(1,"dqbuf: Reading running...\n");
 452                 goto done;
 453         }
 454         retval = -EINVAL;
 455         if (b->type != q->type) {
 456                 dprintk(1,"dqbuf: Wrong type.\n");
 457                 goto done;
 458         }
 459         if (list_empty(&q->stream)) {
 460                 dprintk(1,"dqbuf: stream running\n");
 461                 goto done;
 462         }
 463         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 464         retval = videobuf_waiton(buf, nonblocking, 1);
 465         if (retval < 0) {
 466                 dprintk(1,"dqbuf: waiton returned %d\n",retval);
 467                 goto done;
 468         }
 469         switch (buf->state) {
 470         case STATE_ERROR:
 471                 dprintk(1,"dqbuf: state is error\n");
 472                 retval = -EIO;
 473                 CALL(q,sync,q, buf);
 474                 buf->state = STATE_IDLE;
 475                 break;
 476         case STATE_DONE:
 477                 dprintk(1,"dqbuf: state is done\n");
 478                 CALL(q,sync,q, buf);
 479                 buf->state = STATE_IDLE;
 480                 break;
 481         default:
 482                 dprintk(1,"dqbuf: state invalid\n");
 483                 retval = -EINVAL;
 484                 goto done;
 485         }
 486         list_del(&buf->stream);
 487         memset(b,0,sizeof(*b));
 488         videobuf_status(q,b,buf,q->type);
 489
 490  done:
 491         mutex_unlock(&q->lock);
 492         return retval;
 493 }
 494
 495 int videobuf_streamon(struct videobuf_queue *q)
 496 {
 497         struct videobuf_buffer *buf;
 498         struct list_head *list;
 499         unsigned long flags=0;
 500         int retval;
 501
 502         mutex_lock(&q->lock);
 503         retval = -EBUSY;
 504         if (q->reading)
 505                 goto done;
 506         retval = 0;
 507         if (q->streaming)
 508                 goto done;
 509         q->streaming = 1;
 510         if (q->irqlock)
 511                 spin_lock_irqsave(q->irqlock,flags);
 512         list_for_each(list,&q->stream) {
 513                 buf = list_entry(list, struct videobuf_buffer, stream);
 514                 if (buf->state == STATE_PREPARED)
 515                         q->ops->buf_queue(q,buf);
 516         }
 517         if (q->irqlock)
 518                 spin_unlock_irqrestore(q->irqlock,flags);
 519
 520  done:
 521         mutex_unlock(&q->lock);
 522         return retval;
 523 }
 524
 525 int videobuf_streamoff(struct videobuf_queue *q)
 526 {
 527         int retval = -EINVAL;
 528
 529         mutex_lock(&q->lock);
 530         if (!q->streaming)
 531                 goto done;
 532         videobuf_queue_cancel(q);
 533         q->streaming = 0;
 534         retval = 0;
 535
 536  done:
 537         mutex_unlock(&q->lock);
 538         return retval;
 539 }
 540
 541 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
 542                                       char __user *data,
 543                                       size_t count, loff_t *ppos)
 544 {
 545         enum v4l2_field field;
 546         unsigned long flags=0;
 547         int retval;
 548
 549         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 550
 551         /* setup stuff */
 552         q->read_buf = videobuf_alloc(q);
 553         if (NULL == q->read_buf)
 554                 return -ENOMEM;
 555
 556         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 557         q->read_buf->baddr  = (unsigned long)data;
 558         q->read_buf->bsize  = count;
 559
 560         field = videobuf_next_field(q);
 561         retval = q->ops->buf_prepare(q,q->read_buf,field);
 562         if (0 != retval)
 563                 goto done;
 564
 565         /* start capture & wait */
 566         if (q->irqlock)
 567                 spin_lock_irqsave(q->irqlock,flags);
 568         q->ops->buf_queue(q,q->read_buf);
 569         if (q->irqlock)
 570                 spin_unlock_irqrestore(q->irqlock,flags);
 571         retval = videobuf_waiton(q->read_buf,0,0);
 572         if (0 == retval) {
 573                 CALL(q,sync,q,q->read_buf);
 574                 if (STATE_ERROR == q->read_buf->state)
 575                         retval = -EIO;
 576                 else
 577                         retval = q->read_buf->size;
 578         }
 579
 580  done:
 581         /* cleanup */
 582         q->ops->buf_release(q,q->read_buf);
 583         kfree(q->read_buf);
 584         q->read_buf = NULL;
 585         return retval;
 586 }
 587
 588 ssize_t videobuf_read_one(struct videobuf_queue *q,
 589                           char __user *data, size_t count, loff_t *ppos,
 590                           int nonblocking)
 591 {
 592         enum v4l2_field field;
 593         unsigned long flags=0;
 594         unsigned size, nbufs;
 595         int retval;
 596
 597         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 598
 599         mutex_lock(&q->lock);
 600
 601         nbufs = 1; size = 0;
 602         q->ops->buf_setup(q,&nbufs,&size);
 603
 604         if (NULL == q->read_buf  &&
 605             count >= size        &&
 606             !nonblocking) {
 607                 retval = videobuf_read_zerocopy(q,data,count,ppos);
 608                 if (retval >= 0  ||  retval == -EIO)
 609                         /* ok, all done */
 610                         goto done;
 611                 /* fallback to kernel bounce buffer on failures */
 612         }
 613
 614         if (NULL == q->read_buf) {
 615                 /* need to capture a new frame */
 616                 retval = -ENOMEM;
 617                 q->read_buf = videobuf_alloc(q);
 618
 619                 dprintk(1,"video alloc=0x%p\n", q->read_buf);
 620                 if (NULL == q->read_buf)
 621                         goto done;
 622                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 623                 q->read_buf->bsize = count; /* preferred size */
 624                 field = videobuf_next_field(q);
 625                 retval = q->ops->buf_prepare(q,q->read_buf,field);
 626
 627                 if (0 != retval) {
 628                         kfree (q->read_buf);
 629                         q->read_buf = NULL;
 630                         goto done;
 631                 }
 632                 if (q->irqlock)
 633                         spin_lock_irqsave(q->irqlock,flags);
 634
 635                 q->ops->buf_queue(q,q->read_buf);
 636                 if (q->irqlock)
 637                         spin_unlock_irqrestore(q->irqlock,flags);
 638                 q->read_off = 0;
 639         }
 640
 641         /* wait until capture is done */
 642         retval = videobuf_waiton(q->read_buf, nonblocking, 1);
 643         if (0 != retval)
 644                 goto done;
 645
 646         CALL(q,sync,q,q->read_buf);
 647
 648         if (STATE_ERROR == q->read_buf->state) {
 649                 /* catch I/O errors */
 650                 q->ops->buf_release(q,q->read_buf);
 651                 kfree(q->read_buf);
 652                 q->read_buf = NULL;
 653                 retval = -EIO;
 654                 goto done;
 655         }
 656
 657         /* Copy to userspace */
 658         retval=CALL(q,copy_to_user,q,data,count,nonblocking);
 659         if (retval<0)
 660                 goto done;
 661
 662         q->read_off += retval;
 663         if (q->read_off == q->read_buf->size) {
 664                 /* all data copied, cleanup */
 665                 q->ops->buf_release(q,q->read_buf);
 666                 kfree(q->read_buf);
 667                 q->read_buf = NULL;
 668         }
 669
 670  done:
 671         mutex_unlock(&q->lock);
 672         return retval;
 673 }
 674
 675 int videobuf_read_start(struct videobuf_queue *q)
 676 {
 677         enum v4l2_field field;
 678         unsigned long flags=0;
 679         int count = 0, size = 0;
 680         int err, i;
 681
 682         q->ops->buf_setup(q,&count,&size);
 683         if (count < 2)
 684                 count = 2;
 685         if (count > VIDEO_MAX_FRAME)
 686                 count = VIDEO_MAX_FRAME;
 687         size = PAGE_ALIGN(size);
 688
 689         err = videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
 690         if (err)
 691                 return err;
 692
 693         for (i = 0; i < count; i++) {
 694                 field = videobuf_next_field(q);
 695                 err = q->ops->buf_prepare(q,q->bufs[i],field);
 696                 if (err)
 697                         return err;
 698                 list_add_tail(&q->bufs[i]->stream, &q->stream);
 699         }
 700         if (q->irqlock)
 701                 spin_lock_irqsave(q->irqlock,flags);
 702         for (i = 0; i < count; i++)
 703                 q->ops->buf_queue(q,q->bufs[i]);
 704         if (q->irqlock)
 705                 spin_unlock_irqrestore(q->irqlock,flags);
 706         q->reading = 1;
 707         return 0;
 708 }
 709
 710 void videobuf_read_stop(struct videobuf_queue *q)
 711 {
 712         int i;
 713
 714         videobuf_queue_cancel(q);
 715         videobuf_mmap_free(q);
 716         INIT_LIST_HEAD(&q->stream);
 717         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 718                 if (NULL == q->bufs[i])
 719                         continue;
 720                 kfree(q->bufs[i]);
 721                 q->bufs[i] = NULL;
 722         }
 723         q->read_buf = NULL;
 724         q->reading  = 0;
 725 }
 726
 727 ssize_t videobuf_read_stream(struct videobuf_queue *q,
 728                              char __user *data, size_t count, loff_t *ppos,
 729                              int vbihack, int nonblocking)
 730 {
 731         int rc, retval;
 732         unsigned long flags=0;
 733
 734         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 735
 736         dprintk(2,"%s\n",__FUNCTION__);
 737         mutex_lock(&q->lock);
 738         retval = -EBUSY;
 739         if (q->streaming)
 740                 goto done;
 741         if (!q->reading) {
 742                 retval = videobuf_read_start(q);
 743                 if (retval < 0)
 744                         goto done;
 745         }
 746
 747         retval = 0;
 748         while (count > 0) {
 749                 /* get / wait for data */
 750                 if (NULL == q->read_buf) {
 751                         q->read_buf = list_entry(q->stream.next,
 752                                                  struct videobuf_buffer,
 753                                                  stream);
 754                         list_del(&q->read_buf->stream);
 755                         q->read_off = 0;
 756                 }
 757                 rc = videobuf_waiton(q->read_buf, nonblocking, 1);
 758                 if (rc < 0) {
 759                         if (0 == retval)
 760                                 retval = rc;
 761                         break;
 762                 }
 763
 764                 if (q->read_buf->state == STATE_DONE) {
 765                         rc = CALL (q,copy_stream, q, data, count,
 766                                         retval, vbihack, nonblocking);
 767                         if (rc < 0) {
 768                                 retval = rc;
 769                                 break;
 770                         }
 771                         retval      += rc;
 772                         count       -= rc;
 773                         q->read_off += rc;
 774                 } else {
 775                         /* some error */
 776                         q->read_off = q->read_buf->size;
 777                         if (0 == retval)
 778                                 retval = -EIO;
 779                 }
 780
 781                 /* requeue buffer when done with copying */
 782                 if (q->read_off == q->read_buf->size) {
 783                         list_add_tail(&q->read_buf->stream,
 784                                       &q->stream);
 785                         if (q->irqlock)
 786                                 spin_lock_irqsave(q->irqlock,flags);
 787                         q->ops->buf_queue(q,q->read_buf);
 788                         if (q->irqlock)
 789                                 spin_unlock_irqrestore(q->irqlock,flags);
 790                         q->read_buf = NULL;
 791                 }
 792                 if (retval < 0)
 793                         break;
 794         }
 795
 796  done:
 797         mutex_unlock(&q->lock);
 798         return retval;
 799 }
 800
 801 unsigned int videobuf_poll_stream(struct file *file,
 802                                   struct videobuf_queue *q,
 803                                   poll_table *wait)
 804 {
 805         struct videobuf_buffer *buf = NULL;
 806         unsigned int rc = 0;
 807
 808         mutex_lock(&q->lock);
 809         if (q->streaming) {
 810                 if (!list_empty(&q->stream))
 811                         buf = list_entry(q->stream.next,
 812                                          struct videobuf_buffer, stream);
 813         } else {
 814                 if (!q->reading)
 815                         videobuf_read_start(q);
 816                 if (!q->reading) {
 817                         rc = POLLERR;
 818                 } else if (NULL == q->read_buf) {
 819                         q->read_buf = list_entry(q->stream.next,
 820                                                  struct videobuf_buffer,
 821                                                  stream);
 822                         list_del(&q->read_buf->stream);
 823                         q->read_off = 0;
 824                 }
 825                 buf = q->read_buf;
 826         }
 827         if (!buf)
 828                 rc = POLLERR;
 829
 830         if (0 == rc) {
 831                 poll_wait(file, &buf->done, wait);
 832                 if (buf->state == STATE_DONE ||
 833                     buf->state == STATE_ERROR)
 834                         rc = POLLIN|POLLRDNORM;
 835         }
 836         mutex_unlock(&q->lock);
 837         return rc;
 838 }
 839
 840 int videobuf_mmap_setup(struct videobuf_queue *q,
 841                         unsigned int bcount, unsigned int bsize,
 842                         enum v4l2_memory memory)
 843 {
 844         unsigned int i;
 845         int err;
 846
 847         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 848
 849         err = videobuf_mmap_free(q);
 850         if (0 != err)
 851                 return err;
 852
 853         /* Allocate and initialize buffers */
 854         for (i = 0; i < bcount; i++) {
 855                 q->bufs[i] = videobuf_alloc(q);
 856
 857                 q->bufs[i]->i      = i;
 858                 q->bufs[i]->input  = UNSET;
 859                 q->bufs[i]->memory = memory;
 860                 q->bufs[i]->bsize  = bsize;
 861                 switch (memory) {
 862                 case V4L2_MEMORY_MMAP:
 863                         q->bufs[i]->boff  = bsize * i;
 864                         break;
 865                 case V4L2_MEMORY_USERPTR:
 866                 case V4L2_MEMORY_OVERLAY:
 867                         /* nothing */
 868                         break;
 869                 }
 870         }
 871
 872         dprintk(1,"mmap setup: %d buffers, %d bytes each\n",
 873                 bcount,bsize);
 874
 875         return 0;
 876 }
 877
 878 int videobuf_mmap_free(struct videobuf_queue *q)
 879 {
 880         int i;
 881         int rc;
 882
 883         if (!q)
 884                 return 0;
 885
 886         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 887
 888         rc  = CALL(q,mmap_free,q);
 889         if (rc<0)
 890                 return rc;
 891
 892         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 893                 if (NULL == q->bufs[i])
 894                         continue;
 895                 q->ops->buf_release(q,q->bufs[i]);
 896                 kfree(q->bufs[i]);
 897                 q->bufs[i] = NULL;
 898         }
 899
 900         return rc;
 901 }
 902
 903 int videobuf_mmap_mapper(struct videobuf_queue *q,
 904                          struct vm_area_struct *vma)
 905 {
 906         int retval;
 907
 908         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 909
 910         mutex_lock(&q->lock);
 911         retval=CALL(q,mmap_mapper,q,vma);
 912         mutex_unlock(&q->lock);
 913
 914         return retval;
 915 }
 916
 917 #ifdef CONFIG_VIDEO_V4L1_COMPAT
 918 int videobuf_cgmbuf(struct videobuf_queue *q,
 919                     struct video_mbuf *mbuf, int count)
 920 {
 921         struct v4l2_requestbuffers req;
 922         int rc,i;
 923
 924         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 925
 926         memset(&req,0,sizeof(req));
 927         req.type   = q->type;
 928         req.count  = count;
 929         req.memory = V4L2_MEMORY_MMAP;
 930         rc = videobuf_reqbufs(q,&req);
 931         if (rc < 0)
 932                 return rc;
 933
 934         mbuf->frames = req.count;
 935         mbuf->size   = 0;
 936         for (i = 0; i < mbuf->frames; i++) {
 937                 mbuf->offsets[i]  = q->bufs[i]->boff;
 938                 mbuf->size       += q->bufs[i]->bsize;
 939         }
 940
 941         return 0;
 942 }
 943 #endif
 944
 945 /* --------------------------------------------------------------------- */
 946
 947 EXPORT_SYMBOL_GPL(videobuf_waiton);
 948 EXPORT_SYMBOL_GPL(videobuf_iolock);
 949
 950 EXPORT_SYMBOL_GPL(videobuf_alloc);
 951
 952 EXPORT_SYMBOL_GPL(videobuf_queue_init);
 953 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
 954 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
 955
 956 EXPORT_SYMBOL_GPL(videobuf_next_field);
 957 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
 958 EXPORT_SYMBOL_GPL(videobuf_querybuf);
 959 EXPORT_SYMBOL_GPL(videobuf_qbuf);
 960 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
 961 EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
 962 EXPORT_SYMBOL_GPL(videobuf_streamon);
 963 EXPORT_SYMBOL_GPL(videobuf_streamoff);
 964
 965 EXPORT_SYMBOL_GPL(videobuf_read_start);
 966 EXPORT_SYMBOL_GPL(videobuf_read_stop);
 967 EXPORT_SYMBOL_GPL(videobuf_read_stream);
 968 EXPORT_SYMBOL_GPL(videobuf_read_one);
 969 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
 970
 971 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
 972 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
 973 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
 974
 975 /*
 976  * Local variables:
 977  * c-basic-offset: 8
 978  * End:
 979  */