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   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         /* FIXME: This is required to avoid OOPS on some cases, since mmap_mapper()
  98            method should be called before _iolock.
  99            On some cases, the mmap_mapper() is called only after scheduling.
 100
 101            However, this way is just too dirty! Better to wait for some event.
 102          */
 103         schedule_timeout(HZ);
 104
 105         return CALL(q,iolock,q,vb,fbuf);
 106 }
 107
 108 /* --------------------------------------------------------------------- */
 109
 110
 111 void videobuf_queue_core_init(struct videobuf_queue* q,
 112                          struct videobuf_queue_ops *ops,
 113                          void *dev,
 114                          spinlock_t *irqlock,
 115                          enum v4l2_buf_type type,
 116                          enum v4l2_field field,
 117                          unsigned int msize,
 118                          void *priv,
 119                          struct videobuf_qtype_ops *int_ops)
 120 {
 121         memset(q,0,sizeof(*q));
 122         q->irqlock   = irqlock;
 123         q->dev       = dev;
 124         q->type      = type;
 125         q->field     = field;
 126         q->msize     = msize;
 127         q->ops       = ops;
 128         q->priv_data = priv;
 129         q->int_ops   = int_ops;
 130
 131         /* All buffer operations are mandatory */
 132         BUG_ON (!q->ops->buf_setup);
 133         BUG_ON (!q->ops->buf_prepare);
 134         BUG_ON (!q->ops->buf_queue);
 135         BUG_ON (!q->ops->buf_release);
 136
 137         /* Having implementations for abstract methods are mandatory */
 138         BUG_ON (!q->int_ops);
 139
 140         mutex_init(&q->lock);
 141         INIT_LIST_HEAD(&q->stream);
 142 }
 143
 144 int videobuf_queue_is_busy(struct videobuf_queue *q)
 145 {
 146         int i;
 147
 148         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 149
 150         if (q->streaming) {
 151                 dprintk(1,"busy: streaming active\n");
 152                 return 1;
 153         }
 154         if (q->reading) {
 155                 dprintk(1,"busy: pending read #1\n");
 156                 return 1;
 157         }
 158         if (q->read_buf) {
 159                 dprintk(1,"busy: pending read #2\n");
 160                 return 1;
 161         }
 162         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 163                 if (NULL == q->bufs[i])
 164                         continue;
 165                 if (q->bufs[i]->map) {
 166                         dprintk(1,"busy: buffer #%d mapped\n",i);
 167                         return 1;
 168                 }
 169                 if (q->bufs[i]->state == STATE_QUEUED) {
 170                         dprintk(1,"busy: buffer #%d queued\n",i);
 171                         return 1;
 172                 }
 173                 if (q->bufs[i]->state == STATE_ACTIVE) {
 174                         dprintk(1,"busy: buffer #%d avtive\n",i);
 175                         return 1;
 176                 }
 177         }
 178         return 0;
 179 }
 180
 181 void videobuf_queue_cancel(struct videobuf_queue *q)
 182 {
 183         unsigned long flags=0;
 184         int i;
 185
 186         /* remove queued buffers from list */
 187         if (q->irqlock)
 188                 spin_lock_irqsave(q->irqlock,flags);
 189         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 190                 if (NULL == q->bufs[i])
 191                         continue;
 192                 if (q->bufs[i]->state == STATE_QUEUED) {
 193                         list_del(&q->bufs[i]->queue);
 194                         q->bufs[i]->state = STATE_ERROR;
 195                 }
 196         }
 197         if (q->irqlock)
 198                 spin_unlock_irqrestore(q->irqlock,flags);
 199
 200         /* free all buffers + clear queue */
 201         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 202                 if (NULL == q->bufs[i])
 203                         continue;
 204                 q->ops->buf_release(q,q->bufs[i]);
 205         }
 206         INIT_LIST_HEAD(&q->stream);
 207 }
 208
 209 /* --------------------------------------------------------------------- */
 210
 211 enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
 212 {
 213         enum v4l2_field field = q->field;
 214
 215         BUG_ON(V4L2_FIELD_ANY == field);
 216
 217         if (V4L2_FIELD_ALTERNATE == field) {
 218                 if (V4L2_FIELD_TOP == q->last) {
 219                         field   = V4L2_FIELD_BOTTOM;
 220                         q->last = V4L2_FIELD_BOTTOM;
 221                 } else {
 222                         field   = V4L2_FIELD_TOP;
 223                         q->last = V4L2_FIELD_TOP;
 224                 }
 225         }
 226         return field;
 227 }
 228
 229 static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
 230                             struct videobuf_buffer *vb, enum v4l2_buf_type type)
 231 {
 232         MAGIC_CHECK(vb->magic,MAGIC_BUFFER);
 233         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 234
 235         b->index    = vb->i;
 236         b->type     = type;
 237
 238         b->memory   = vb->memory;
 239         switch (b->memory) {
 240         case V4L2_MEMORY_MMAP:
 241                 b->m.offset  = vb->boff;
 242                 b->length    = vb->bsize;
 243                 break;
 244         case V4L2_MEMORY_USERPTR:
 245                 b->m.userptr = vb->baddr;
 246                 b->length    = vb->bsize;
 247                 break;
 248         case V4L2_MEMORY_OVERLAY:
 249                 b->m.offset  = vb->boff;
 250                 break;
 251         }
 252
 253         b->flags    = 0;
 254         if (vb->map)
 255                 b->flags |= V4L2_BUF_FLAG_MAPPED;
 256
 257         switch (vb->state) {
 258         case STATE_PREPARED:
 259         case STATE_QUEUED:
 260         case STATE_ACTIVE:
 261                 b->flags |= V4L2_BUF_FLAG_QUEUED;
 262                 break;
 263         case STATE_DONE:
 264         case STATE_ERROR:
 265                 b->flags |= V4L2_BUF_FLAG_DONE;
 266                 break;
 267         case STATE_NEEDS_INIT:
 268         case STATE_IDLE:
 269                 /* nothing */
 270                 break;
 271         }
 272
 273         if (vb->input != UNSET) {
 274                 b->flags |= V4L2_BUF_FLAG_INPUT;
 275                 b->input  = vb->input;
 276         }
 277
 278         b->field     = vb->field;
 279         b->timestamp = vb->ts;
 280         b->bytesused = vb->size;
 281         b->sequence  = vb->field_count >> 1;
 282 }
 283
 284 int videobuf_reqbufs(struct videobuf_queue *q,
 285                  struct v4l2_requestbuffers *req)
 286 {
 287         unsigned int size,count;
 288         int retval;
 289
 290         if (req->type != q->type) {
 291                 dprintk(1,"reqbufs: queue type invalid\n");
 292                 return -EINVAL;
 293         }
 294         if (req->count < 1) {
 295                 dprintk(1,"reqbufs: count invalid (%d)\n",req->count);
 296                 return -EINVAL;
 297         }
 298         if (req->memory != V4L2_MEMORY_MMAP     &&
 299             req->memory != V4L2_MEMORY_USERPTR  &&
 300             req->memory != V4L2_MEMORY_OVERLAY) {
 301                 dprintk(1,"reqbufs: memory type invalid\n");
 302                 return -EINVAL;
 303         }
 304
 305         mutex_lock(&q->lock);
 306         if (q->streaming) {
 307                 dprintk(1,"reqbufs: streaming already exists\n");
 308                 retval = -EBUSY;
 309                 goto done;
 310         }
 311         if (!list_empty(&q->stream)) {
 312                 dprintk(1,"reqbufs: stream running\n");
 313                 retval = -EBUSY;
 314                 goto done;
 315         }
 316
 317         count = req->count;
 318         if (count > VIDEO_MAX_FRAME)
 319                 count = VIDEO_MAX_FRAME;
 320         size = 0;
 321         q->ops->buf_setup(q,&count,&size);
 322         size = PAGE_ALIGN(size);
 323         dprintk(1,"reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
 324                 count, size, (count*size)>>PAGE_SHIFT);
 325
 326         retval = videobuf_mmap_setup(q,count,size,req->memory);
 327         if (retval < 0) {
 328                 dprintk(1,"reqbufs: mmap setup returned %d\n",retval);
 329                 goto done;
 330         }
 331
 332         req->count = retval;
 333
 334  done:
 335         mutex_unlock(&q->lock);
 336         return retval;
 337 }
 338
 339 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 340 {
 341         if (unlikely(b->type != q->type)) {
 342                 dprintk(1,"querybuf: Wrong type.\n");
 343                 return -EINVAL;
 344         }
 345         if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME)) {
 346                 dprintk(1,"querybuf: index out of range.\n");
 347                 return -EINVAL;
 348         }
 349         if (unlikely(NULL == q->bufs[b->index])) {
 350                 dprintk(1,"querybuf: buffer is null.\n");
 351                 return -EINVAL;
 352         }
 353         videobuf_status(q,b,q->bufs[b->index],q->type);
 354         return 0;
 355 }
 356
 357 int videobuf_qbuf(struct videobuf_queue *q,
 358               struct v4l2_buffer *b)
 359 {
 360         struct videobuf_buffer *buf;
 361         enum v4l2_field field;
 362         unsigned long flags=0;
 363         int retval;
 364
 365         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 366
 367         if (b->memory == V4L2_MEMORY_MMAP)
 368                 down_read(&current->mm->mmap_sem);
 369
 370         mutex_lock(&q->lock);
 371         retval = -EBUSY;
 372         if (q->reading) {
 373                 dprintk(1,"qbuf: Reading running...\n");
 374                 goto done;
 375         }
 376         retval = -EINVAL;
 377         if (b->type != q->type) {
 378                 dprintk(1,"qbuf: Wrong type.\n");
 379                 goto done;
 380         }
 381         if (b->index < 0 || b->index >= VIDEO_MAX_FRAME) {
 382                 dprintk(1,"qbuf: index out of range.\n");
 383                 goto done;
 384         }
 385         buf = q->bufs[b->index];
 386         if (NULL == buf) {
 387                 dprintk(1,"qbuf: buffer is null.\n");
 388                 goto done;
 389         }
 390         MAGIC_CHECK(buf->magic,MAGIC_BUFFER);
 391         if (buf->memory != b->memory) {
 392                 dprintk(1,"qbuf: memory type is wrong.\n");
 393                 goto done;
 394         }
 395         if (buf->state != STATE_NEEDS_INIT && buf->state != STATE_IDLE) {
 396                 dprintk(1,"qbuf: buffer is already queued or active.\n");
 397                 goto done;
 398         }
 399
 400         if (b->flags & V4L2_BUF_FLAG_INPUT) {
 401                 if (b->input >= q->inputs) {
 402                         dprintk(1,"qbuf: wrong input.\n");
 403                         goto done;
 404                 }
 405                 buf->input = b->input;
 406         } else {
 407                 buf->input = UNSET;
 408         }
 409
 410         switch (b->memory) {
 411         case V4L2_MEMORY_MMAP:
 412                 if (0 == buf->baddr) {
 413                         dprintk(1,"qbuf: mmap requested but buffer addr is zero!\n");
 414                         goto done;
 415                 }
 416                 break;
 417         case V4L2_MEMORY_USERPTR:
 418                 if (b->length < buf->bsize) {
 419                         dprintk(1,"qbuf: buffer length is not enough\n");
 420                         goto done;
 421                 }
 422                 if (STATE_NEEDS_INIT != buf->state && buf->baddr != b->m.userptr)
 423                         q->ops->buf_release(q,buf);
 424                 buf->baddr = b->m.userptr;
 425                 break;
 426         case V4L2_MEMORY_OVERLAY:
 427                 buf->boff = b->m.offset;
 428                 break;
 429         default:
 430                 dprintk(1,"qbuf: wrong memory type\n");
 431                 goto done;
 432         }
 433
 434         dprintk(1,"qbuf: requesting next field\n");
 435         field = videobuf_next_field(q);
 436         retval = q->ops->buf_prepare(q,buf,field);
 437         if (0 != retval) {
 438                 dprintk(1,"qbuf: buffer_prepare returned %d\n",retval);
 439                 goto done;
 440         }
 441
 442         list_add_tail(&buf->stream,&q->stream);
 443         if (q->streaming) {
 444                 if (q->irqlock)
 445                         spin_lock_irqsave(q->irqlock,flags);
 446                 q->ops->buf_queue(q,buf);
 447                 if (q->irqlock)
 448                         spin_unlock_irqrestore(q->irqlock,flags);
 449         }
 450         dprintk(1,"qbuf: succeded\n");
 451         retval = 0;
 452
 453  done:
 454         mutex_unlock(&q->lock);
 455
 456         if (b->memory == V4L2_MEMORY_MMAP)
 457                 up_read(&current->mm->mmap_sem);
 458
 459         return retval;
 460 }
 461
 462 int videobuf_dqbuf(struct videobuf_queue *q,
 463                struct v4l2_buffer *b, int nonblocking)
 464 {
 465         struct videobuf_buffer *buf;
 466         int retval;
 467
 468         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 469
 470         mutex_lock(&q->lock);
 471         retval = -EBUSY;
 472         if (q->reading) {
 473                 dprintk(1,"dqbuf: Reading running...\n");
 474                 goto done;
 475         }
 476         retval = -EINVAL;
 477         if (b->type != q->type) {
 478                 dprintk(1,"dqbuf: Wrong type.\n");
 479                 goto done;
 480         }
 481         if (list_empty(&q->stream)) {
 482                 dprintk(1,"dqbuf: stream running\n");
 483                 goto done;
 484         }
 485         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 486         retval = videobuf_waiton(buf, nonblocking, 1);
 487         if (retval < 0) {
 488                 dprintk(1,"dqbuf: waiton returned %d\n",retval);
 489                 goto done;
 490         }
 491         switch (buf->state) {
 492         case STATE_ERROR:
 493                 dprintk(1,"dqbuf: state is error\n");
 494                 retval = -EIO;
 495                 CALL(q,sync,q, buf);
 496                 buf->state = STATE_IDLE;
 497                 break;
 498         case STATE_DONE:
 499                 dprintk(1,"dqbuf: state is done\n");
 500                 CALL(q,sync,q, buf);
 501                 buf->state = STATE_IDLE;
 502                 break;
 503         default:
 504                 dprintk(1,"dqbuf: state invalid\n");
 505                 retval = -EINVAL;
 506                 goto done;
 507         }
 508         list_del(&buf->stream);
 509         memset(b,0,sizeof(*b));
 510         videobuf_status(q,b,buf,q->type);
 511
 512  done:
 513         mutex_unlock(&q->lock);
 514         return retval;
 515 }
 516
 517 int videobuf_streamon(struct videobuf_queue *q)
 518 {
 519         struct videobuf_buffer *buf;
 520         unsigned long flags=0;
 521         int retval;
 522
 523         mutex_lock(&q->lock);
 524         retval = -EBUSY;
 525         if (q->reading)
 526                 goto done;
 527         retval = 0;
 528         if (q->streaming)
 529                 goto done;
 530         q->streaming = 1;
 531         if (q->irqlock)
 532                 spin_lock_irqsave(q->irqlock,flags);
 533         list_for_each_entry(buf, &q->stream, stream)
 534                 if (buf->state == STATE_PREPARED)
 535                         q->ops->buf_queue(q,buf);
 536         if (q->irqlock)
 537                 spin_unlock_irqrestore(q->irqlock,flags);
 538
 539  done:
 540         mutex_unlock(&q->lock);
 541         return retval;
 542 }
 543
 544 int videobuf_streamoff(struct videobuf_queue *q)
 545 {
 546         int retval = -EINVAL;
 547
 548         mutex_lock(&q->lock);
 549         if (!q->streaming)
 550                 goto done;
 551         videobuf_queue_cancel(q);
 552         q->streaming = 0;
 553         retval = 0;
 554
 555  done:
 556         mutex_unlock(&q->lock);
 557         return retval;
 558 }
 559
 560 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
 561                                       char __user *data,
 562                                       size_t count, loff_t *ppos)
 563 {
 564         enum v4l2_field field;
 565         unsigned long flags=0;
 566         int retval;
 567
 568         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 569
 570         /* setup stuff */
 571         q->read_buf = videobuf_alloc(q);
 572         if (NULL == q->read_buf)
 573                 return -ENOMEM;
 574
 575         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 576         q->read_buf->baddr  = (unsigned long)data;
 577         q->read_buf->bsize  = count;
 578
 579         field = videobuf_next_field(q);
 580         retval = q->ops->buf_prepare(q,q->read_buf,field);
 581         if (0 != retval)
 582                 goto done;
 583
 584         /* start capture & wait */
 585         if (q->irqlock)
 586                 spin_lock_irqsave(q->irqlock,flags);
 587         q->ops->buf_queue(q,q->read_buf);
 588         if (q->irqlock)
 589                 spin_unlock_irqrestore(q->irqlock,flags);
 590         retval = videobuf_waiton(q->read_buf,0,0);
 591         if (0 == retval) {
 592                 CALL(q,sync,q,q->read_buf);
 593                 if (STATE_ERROR == q->read_buf->state)
 594                         retval = -EIO;
 595                 else
 596                         retval = q->read_buf->size;
 597         }
 598
 599  done:
 600         /* cleanup */
 601         q->ops->buf_release(q,q->read_buf);
 602         kfree(q->read_buf);
 603         q->read_buf = NULL;
 604         return retval;
 605 }
 606
 607 ssize_t videobuf_read_one(struct videobuf_queue *q,
 608                           char __user *data, size_t count, loff_t *ppos,
 609                           int nonblocking)
 610 {
 611         enum v4l2_field field;
 612         unsigned long flags=0;
 613         unsigned size, nbufs;
 614         int retval;
 615
 616         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 617
 618         mutex_lock(&q->lock);
 619
 620         nbufs = 1; size = 0;
 621         q->ops->buf_setup(q,&nbufs,&size);
 622
 623         if (NULL == q->read_buf  &&
 624             count >= size        &&
 625             !nonblocking) {
 626                 retval = videobuf_read_zerocopy(q,data,count,ppos);
 627                 if (retval >= 0  ||  retval == -EIO)
 628                         /* ok, all done */
 629                         goto done;
 630                 /* fallback to kernel bounce buffer on failures */
 631         }
 632
 633         if (NULL == q->read_buf) {
 634                 /* need to capture a new frame */
 635                 retval = -ENOMEM;
 636                 q->read_buf = videobuf_alloc(q);
 637
 638                 dprintk(1,"video alloc=0x%p\n", q->read_buf);
 639                 if (NULL == q->read_buf)
 640                         goto done;
 641                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 642                 q->read_buf->bsize = count; /* preferred size */
 643                 field = videobuf_next_field(q);
 644                 retval = q->ops->buf_prepare(q,q->read_buf,field);
 645
 646                 if (0 != retval) {
 647                         kfree (q->read_buf);
 648                         q->read_buf = NULL;
 649                         goto done;
 650                 }
 651                 if (q->irqlock)
 652                         spin_lock_irqsave(q->irqlock,flags);
 653
 654                 q->ops->buf_queue(q,q->read_buf);
 655                 if (q->irqlock)
 656                         spin_unlock_irqrestore(q->irqlock,flags);
 657                 q->read_off = 0;
 658         }
 659
 660         /* wait until capture is done */
 661         retval = videobuf_waiton(q->read_buf, nonblocking, 1);
 662         if (0 != retval)
 663                 goto done;
 664
 665         CALL(q,sync,q,q->read_buf);
 666
 667         if (STATE_ERROR == q->read_buf->state) {
 668                 /* catch I/O errors */
 669                 q->ops->buf_release(q,q->read_buf);
 670                 kfree(q->read_buf);
 671                 q->read_buf = NULL;
 672                 retval = -EIO;
 673                 goto done;
 674         }
 675
 676         /* Copy to userspace */
 677         retval=CALL(q,copy_to_user,q,data,count,nonblocking);
 678         if (retval<0)
 679                 goto done;
 680
 681         q->read_off += retval;
 682         if (q->read_off == q->read_buf->size) {
 683                 /* all data copied, cleanup */
 684                 q->ops->buf_release(q,q->read_buf);
 685                 kfree(q->read_buf);
 686                 q->read_buf = NULL;
 687         }
 688
 689  done:
 690         mutex_unlock(&q->lock);
 691         return retval;
 692 }
 693
 694 int videobuf_read_start(struct videobuf_queue *q)
 695 {
 696         enum v4l2_field field;
 697         unsigned long flags=0;
 698         unsigned int count = 0, size = 0;
 699         int err, i;
 700
 701         q->ops->buf_setup(q,&count,&size);
 702         if (count < 2)
 703                 count = 2;
 704         if (count > VIDEO_MAX_FRAME)
 705                 count = VIDEO_MAX_FRAME;
 706         size = PAGE_ALIGN(size);
 707
 708         err = videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
 709         if (err < 0)
 710                 return err;
 711
 712         count = err;
 713
 714         for (i = 0; i < count; i++) {
 715                 field = videobuf_next_field(q);
 716                 err = q->ops->buf_prepare(q,q->bufs[i],field);
 717                 if (err)
 718                         return err;
 719                 list_add_tail(&q->bufs[i]->stream, &q->stream);
 720         }
 721         if (q->irqlock)
 722                 spin_lock_irqsave(q->irqlock,flags);
 723         for (i = 0; i < count; i++)
 724                 q->ops->buf_queue(q,q->bufs[i]);
 725         if (q->irqlock)
 726                 spin_unlock_irqrestore(q->irqlock,flags);
 727         q->reading = 1;
 728         return 0;
 729 }
 730
 731 void videobuf_read_stop(struct videobuf_queue *q)
 732 {
 733         int i;
 734
 735         videobuf_queue_cancel(q);
 736         videobuf_mmap_free(q);
 737         INIT_LIST_HEAD(&q->stream);
 738         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 739                 if (NULL == q->bufs[i])
 740                         continue;
 741                 kfree(q->bufs[i]);
 742                 q->bufs[i] = NULL;
 743         }
 744         q->read_buf = NULL;
 745         q->reading  = 0;
 746 }
 747
 748 ssize_t videobuf_read_stream(struct videobuf_queue *q,
 749                              char __user *data, size_t count, loff_t *ppos,
 750                              int vbihack, int nonblocking)
 751 {
 752         int rc, retval;
 753         unsigned long flags=0;
 754
 755         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 756
 757         dprintk(2,"%s\n",__FUNCTION__);
 758         mutex_lock(&q->lock);
 759         retval = -EBUSY;
 760         if (q->streaming)
 761                 goto done;
 762         if (!q->reading) {
 763                 retval = videobuf_read_start(q);
 764                 if (retval < 0)
 765                         goto done;
 766         }
 767
 768         retval = 0;
 769         while (count > 0) {
 770                 /* get / wait for data */
 771                 if (NULL == q->read_buf) {
 772                         q->read_buf = list_entry(q->stream.next,
 773                                                  struct videobuf_buffer,
 774                                                  stream);
 775                         list_del(&q->read_buf->stream);
 776                         q->read_off = 0;
 777                 }
 778                 rc = videobuf_waiton(q->read_buf, nonblocking, 1);
 779                 if (rc < 0) {
 780                         if (0 == retval)
 781                                 retval = rc;
 782                         break;
 783                 }
 784
 785                 if (q->read_buf->state == STATE_DONE) {
 786                         rc = CALL (q,copy_stream, q, data + retval, count,
 787                                         retval, vbihack, nonblocking);
 788                         if (rc < 0) {
 789                                 retval = rc;
 790                                 break;
 791                         }
 792                         retval      += rc;
 793                         count       -= rc;
 794                         q->read_off += rc;
 795                 } else {
 796                         /* some error */
 797                         q->read_off = q->read_buf->size;
 798                         if (0 == retval)
 799                                 retval = -EIO;
 800                 }
 801
 802                 /* requeue buffer when done with copying */
 803                 if (q->read_off == q->read_buf->size) {
 804                         list_add_tail(&q->read_buf->stream,
 805                                       &q->stream);
 806                         if (q->irqlock)
 807                                 spin_lock_irqsave(q->irqlock,flags);
 808                         q->ops->buf_queue(q,q->read_buf);
 809                         if (q->irqlock)
 810                                 spin_unlock_irqrestore(q->irqlock,flags);
 811                         q->read_buf = NULL;
 812                 }
 813                 if (retval < 0)
 814                         break;
 815         }
 816
 817  done:
 818         mutex_unlock(&q->lock);
 819         return retval;
 820 }
 821
 822 unsigned int videobuf_poll_stream(struct file *file,
 823                                   struct videobuf_queue *q,
 824                                   poll_table *wait)
 825 {
 826         struct videobuf_buffer *buf = NULL;
 827         unsigned int rc = 0;
 828
 829         mutex_lock(&q->lock);
 830         if (q->streaming) {
 831                 if (!list_empty(&q->stream))
 832                         buf = list_entry(q->stream.next,
 833                                          struct videobuf_buffer, stream);
 834         } else {
 835                 if (!q->reading)
 836                         videobuf_read_start(q);
 837                 if (!q->reading) {
 838                         rc = POLLERR;
 839                 } else if (NULL == q->read_buf) {
 840                         q->read_buf = list_entry(q->stream.next,
 841                                                  struct videobuf_buffer,
 842                                                  stream);
 843                         list_del(&q->read_buf->stream);
 844                         q->read_off = 0;
 845                 }
 846                 buf = q->read_buf;
 847         }
 848         if (!buf)
 849                 rc = POLLERR;
 850
 851         if (0 == rc) {
 852                 poll_wait(file, &buf->done, wait);
 853                 if (buf->state == STATE_DONE ||
 854                     buf->state == STATE_ERROR)
 855                         rc = POLLIN|POLLRDNORM;
 856         }
 857         mutex_unlock(&q->lock);
 858         return rc;
 859 }
 860
 861 int videobuf_mmap_setup(struct videobuf_queue *q,
 862                         unsigned int bcount, unsigned int bsize,
 863                         enum v4l2_memory memory)
 864 {
 865         unsigned int i;
 866         int err;
 867
 868         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 869
 870         err = videobuf_mmap_free(q);
 871         if (0 != err)
 872                 return err;
 873
 874         /* Allocate and initialize buffers */
 875         for (i = 0; i < bcount; i++) {
 876                 q->bufs[i] = videobuf_alloc(q);
 877
 878                 if (q->bufs[i] == NULL)
 879                         break;
 880
 881                 q->bufs[i]->i      = i;
 882                 q->bufs[i]->input  = UNSET;
 883                 q->bufs[i]->memory = memory;
 884                 q->bufs[i]->bsize  = bsize;
 885                 switch (memory) {
 886                 case V4L2_MEMORY_MMAP:
 887                         q->bufs[i]->boff  = bsize * i;
 888                         break;
 889                 case V4L2_MEMORY_USERPTR:
 890                 case V4L2_MEMORY_OVERLAY:
 891                         /* nothing */
 892                         break;
 893                 }
 894         }
 895
 896         if (!i)
 897                 return -ENOMEM;
 898
 899         dprintk(1,"mmap setup: %d buffers, %d bytes each\n",
 900                 i, bsize);
 901
 902         return i;
 903 }
 904
 905 int videobuf_mmap_free(struct videobuf_queue *q)
 906 {
 907         int i;
 908         int rc;
 909
 910         if (!q)
 911                 return 0;
 912
 913         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 914
 915         rc  = CALL(q,mmap_free,q);
 916         if (rc<0)
 917                 return rc;
 918
 919         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 920                 if (NULL == q->bufs[i])
 921                         continue;
 922                 q->ops->buf_release(q,q->bufs[i]);
 923                 kfree(q->bufs[i]);
 924                 q->bufs[i] = NULL;
 925         }
 926
 927         return rc;
 928 }
 929
 930 int videobuf_mmap_mapper(struct videobuf_queue *q,
 931                          struct vm_area_struct *vma)
 932 {
 933         int retval;
 934
 935         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 936
 937         mutex_lock(&q->lock);
 938         retval=CALL(q,mmap_mapper,q,vma);
 939         mutex_unlock(&q->lock);
 940
 941         return retval;
 942 }
 943
 944 #ifdef CONFIG_VIDEO_V4L1_COMPAT
 945 int videobuf_cgmbuf(struct videobuf_queue *q,
 946                     struct video_mbuf *mbuf, int count)
 947 {
 948         struct v4l2_requestbuffers req;
 949         int rc,i;
 950
 951         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 952
 953         memset(&req,0,sizeof(req));
 954         req.type   = q->type;
 955         req.count  = count;
 956         req.memory = V4L2_MEMORY_MMAP;
 957         rc = videobuf_reqbufs(q,&req);
 958         if (rc < 0)
 959                 return rc;
 960
 961         mbuf->frames = req.count;
 962         mbuf->size   = 0;
 963         for (i = 0; i < mbuf->frames; i++) {
 964                 mbuf->offsets[i]  = q->bufs[i]->boff;
 965                 mbuf->size       += q->bufs[i]->bsize;
 966         }
 967
 968         return 0;
 969 }
 970 #endif
 971
 972 /* --------------------------------------------------------------------- */
 973
 974 EXPORT_SYMBOL_GPL(videobuf_waiton);
 975 EXPORT_SYMBOL_GPL(videobuf_iolock);
 976
 977 EXPORT_SYMBOL_GPL(videobuf_alloc);
 978
 979 EXPORT_SYMBOL_GPL(videobuf_queue_core_init);
 980 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
 981 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
 982
 983 EXPORT_SYMBOL_GPL(videobuf_next_field);
 984 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
 985 EXPORT_SYMBOL_GPL(videobuf_querybuf);
 986 EXPORT_SYMBOL_GPL(videobuf_qbuf);
 987 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
 988 EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
 989 EXPORT_SYMBOL_GPL(videobuf_streamon);
 990 EXPORT_SYMBOL_GPL(videobuf_streamoff);
 991
 992 EXPORT_SYMBOL_GPL(videobuf_read_start);
 993 EXPORT_SYMBOL_GPL(videobuf_read_stop);
 994 EXPORT_SYMBOL_GPL(videobuf_read_stream);
 995 EXPORT_SYMBOL_GPL(videobuf_read_one);
 996 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
 997
 998 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
 999 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
1000 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
1001
1002 /*
1003  * Local variables:
1004  * c-basic-offset: 8
1005  * End:
1006  */