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         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         if (b->memory == V4L2_MEMORY_MMAP)
 353                 down_read(&current->mm->mmap_sem);
 354
 355         mutex_lock(&q->lock);
 356         retval = -EBUSY;
 357         if (q->reading) {
 358                 dprintk(1,"qbuf: Reading running...\n");
 359                 goto done;
 360         }
 361         retval = -EINVAL;
 362         if (b->type != q->type) {
 363                 dprintk(1,"qbuf: Wrong type.\n");
 364                 goto done;
 365         }
 366         if (b->index < 0 || b->index >= VIDEO_MAX_FRAME) {
 367                 dprintk(1,"qbuf: index out of range.\n");
 368                 goto done;
 369         }
 370         buf = q->bufs[b->index];
 371         if (NULL == buf) {
 372                 dprintk(1,"qbuf: buffer is null.\n");
 373                 goto done;
 374         }
 375         MAGIC_CHECK(buf->magic,MAGIC_BUFFER);
 376         if (buf->memory != b->memory) {
 377                 dprintk(1,"qbuf: memory type is wrong.\n");
 378                 goto done;
 379         }
 380         if (buf->state != STATE_NEEDS_INIT && buf->state != STATE_IDLE) {
 381                 dprintk(1,"qbuf: buffer is already queued or active.\n");
 382                 goto done;
 383         }
 384
 385         if (b->flags & V4L2_BUF_FLAG_INPUT) {
 386                 if (b->input >= q->inputs) {
 387                         dprintk(1,"qbuf: wrong input.\n");
 388                         goto done;
 389                 }
 390                 buf->input = b->input;
 391         } else {
 392                 buf->input = UNSET;
 393         }
 394
 395         switch (b->memory) {
 396         case V4L2_MEMORY_MMAP:
 397                 if (0 == buf->baddr) {
 398                         dprintk(1,"qbuf: mmap requested but buffer addr is zero!\n");
 399                         goto done;
 400                 }
 401                 break;
 402         case V4L2_MEMORY_USERPTR:
 403                 if (b->length < buf->bsize) {
 404                         dprintk(1,"qbuf: buffer length is not enough\n");
 405                         goto done;
 406                 }
 407                 if (STATE_NEEDS_INIT != buf->state && buf->baddr != b->m.userptr)
 408                         q->ops->buf_release(q,buf);
 409                 buf->baddr = b->m.userptr;
 410                 break;
 411         case V4L2_MEMORY_OVERLAY:
 412                 buf->boff = b->m.offset;
 413                 break;
 414         default:
 415                 dprintk(1,"qbuf: wrong memory type\n");
 416                 goto done;
 417         }
 418
 419         dprintk(1,"qbuf: requesting next field\n");
 420         field = videobuf_next_field(q);
 421         retval = q->ops->buf_prepare(q,buf,field);
 422         if (0 != retval) {
 423                 dprintk(1,"qbuf: buffer_prepare returned %d\n",retval);
 424                 goto done;
 425         }
 426
 427         list_add_tail(&buf->stream,&q->stream);
 428         if (q->streaming) {
 429                 if (q->irqlock)
 430                         spin_lock_irqsave(q->irqlock,flags);
 431                 q->ops->buf_queue(q,buf);
 432                 if (q->irqlock)
 433                         spin_unlock_irqrestore(q->irqlock,flags);
 434         }
 435         dprintk(1,"qbuf: succeded\n");
 436         retval = 0;
 437
 438  done:
 439         mutex_unlock(&q->lock);
 440
 441         if (b->memory == V4L2_MEMORY_MMAP)
 442                 up_read(&current->mm->mmap_sem);
 443
 444         return retval;
 445 }
 446
 447 int videobuf_dqbuf(struct videobuf_queue *q,
 448                struct v4l2_buffer *b, int nonblocking)
 449 {
 450         struct videobuf_buffer *buf;
 451         int retval;
 452
 453         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 454
 455         mutex_lock(&q->lock);
 456         retval = -EBUSY;
 457         if (q->reading) {
 458                 dprintk(1,"dqbuf: Reading running...\n");
 459                 goto done;
 460         }
 461         retval = -EINVAL;
 462         if (b->type != q->type) {
 463                 dprintk(1,"dqbuf: Wrong type.\n");
 464                 goto done;
 465         }
 466         if (list_empty(&q->stream)) {
 467                 dprintk(1,"dqbuf: stream running\n");
 468                 goto done;
 469         }
 470         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 471         retval = videobuf_waiton(buf, nonblocking, 1);
 472         if (retval < 0) {
 473                 dprintk(1,"dqbuf: waiton returned %d\n",retval);
 474                 goto done;
 475         }
 476         switch (buf->state) {
 477         case STATE_ERROR:
 478                 dprintk(1,"dqbuf: state is error\n");
 479                 retval = -EIO;
 480                 CALL(q,sync,q, buf);
 481                 buf->state = STATE_IDLE;
 482                 break;
 483         case STATE_DONE:
 484                 dprintk(1,"dqbuf: state is done\n");
 485                 CALL(q,sync,q, buf);
 486                 buf->state = STATE_IDLE;
 487                 break;
 488         default:
 489                 dprintk(1,"dqbuf: state invalid\n");
 490                 retval = -EINVAL;
 491                 goto done;
 492         }
 493         list_del(&buf->stream);
 494         memset(b,0,sizeof(*b));
 495         videobuf_status(q,b,buf,q->type);
 496
 497  done:
 498         mutex_unlock(&q->lock);
 499         return retval;
 500 }
 501
 502 int videobuf_streamon(struct videobuf_queue *q)
 503 {
 504         struct videobuf_buffer *buf;
 505         struct list_head *list;
 506         unsigned long flags=0;
 507         int retval;
 508
 509         mutex_lock(&q->lock);
 510         retval = -EBUSY;
 511         if (q->reading)
 512                 goto done;
 513         retval = 0;
 514         if (q->streaming)
 515                 goto done;
 516         q->streaming = 1;
 517         if (q->irqlock)
 518                 spin_lock_irqsave(q->irqlock,flags);
 519         list_for_each(list,&q->stream) {
 520                 buf = list_entry(list, struct videobuf_buffer, stream);
 521                 if (buf->state == STATE_PREPARED)
 522                         q->ops->buf_queue(q,buf);
 523         }
 524         if (q->irqlock)
 525                 spin_unlock_irqrestore(q->irqlock,flags);
 526
 527  done:
 528         mutex_unlock(&q->lock);
 529         return retval;
 530 }
 531
 532 int videobuf_streamoff(struct videobuf_queue *q)
 533 {
 534         int retval = -EINVAL;
 535
 536         mutex_lock(&q->lock);
 537         if (!q->streaming)
 538                 goto done;
 539         videobuf_queue_cancel(q);
 540         q->streaming = 0;
 541         retval = 0;
 542
 543  done:
 544         mutex_unlock(&q->lock);
 545         return retval;
 546 }
 547
 548 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
 549                                       char __user *data,
 550                                       size_t count, loff_t *ppos)
 551 {
 552         enum v4l2_field field;
 553         unsigned long flags=0;
 554         int retval;
 555
 556         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 557
 558         /* setup stuff */
 559         q->read_buf = videobuf_alloc(q);
 560         if (NULL == q->read_buf)
 561                 return -ENOMEM;
 562
 563         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 564         q->read_buf->baddr  = (unsigned long)data;
 565         q->read_buf->bsize  = count;
 566
 567         field = videobuf_next_field(q);
 568         retval = q->ops->buf_prepare(q,q->read_buf,field);
 569         if (0 != retval)
 570                 goto done;
 571
 572         /* start capture & wait */
 573         if (q->irqlock)
 574                 spin_lock_irqsave(q->irqlock,flags);
 575         q->ops->buf_queue(q,q->read_buf);
 576         if (q->irqlock)
 577                 spin_unlock_irqrestore(q->irqlock,flags);
 578         retval = videobuf_waiton(q->read_buf,0,0);
 579         if (0 == retval) {
 580                 CALL(q,sync,q,q->read_buf);
 581                 if (STATE_ERROR == q->read_buf->state)
 582                         retval = -EIO;
 583                 else
 584                         retval = q->read_buf->size;
 585         }
 586
 587  done:
 588         /* cleanup */
 589         q->ops->buf_release(q,q->read_buf);
 590         kfree(q->read_buf);
 591         q->read_buf = NULL;
 592         return retval;
 593 }
 594
 595 ssize_t videobuf_read_one(struct videobuf_queue *q,
 596                           char __user *data, size_t count, loff_t *ppos,
 597                           int nonblocking)
 598 {
 599         enum v4l2_field field;
 600         unsigned long flags=0;
 601         unsigned size, nbufs;
 602         int retval;
 603
 604         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 605
 606         mutex_lock(&q->lock);
 607
 608         nbufs = 1; size = 0;
 609         q->ops->buf_setup(q,&nbufs,&size);
 610
 611         if (NULL == q->read_buf  &&
 612             count >= size        &&
 613             !nonblocking) {
 614                 retval = videobuf_read_zerocopy(q,data,count,ppos);
 615                 if (retval >= 0  ||  retval == -EIO)
 616                         /* ok, all done */
 617                         goto done;
 618                 /* fallback to kernel bounce buffer on failures */
 619         }
 620
 621         if (NULL == q->read_buf) {
 622                 /* need to capture a new frame */
 623                 retval = -ENOMEM;
 624                 q->read_buf = videobuf_alloc(q);
 625
 626                 dprintk(1,"video alloc=0x%p\n", q->read_buf);
 627                 if (NULL == q->read_buf)
 628                         goto done;
 629                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 630                 q->read_buf->bsize = count; /* preferred size */
 631                 field = videobuf_next_field(q);
 632                 retval = q->ops->buf_prepare(q,q->read_buf,field);
 633
 634                 if (0 != retval) {
 635                         kfree (q->read_buf);
 636                         q->read_buf = NULL;
 637                         goto done;
 638                 }
 639                 if (q->irqlock)
 640                         spin_lock_irqsave(q->irqlock,flags);
 641
 642                 q->ops->buf_queue(q,q->read_buf);
 643                 if (q->irqlock)
 644                         spin_unlock_irqrestore(q->irqlock,flags);
 645                 q->read_off = 0;
 646         }
 647
 648         /* wait until capture is done */
 649         retval = videobuf_waiton(q->read_buf, nonblocking, 1);
 650         if (0 != retval)
 651                 goto done;
 652
 653         CALL(q,sync,q,q->read_buf);
 654
 655         if (STATE_ERROR == q->read_buf->state) {
 656                 /* catch I/O errors */
 657                 q->ops->buf_release(q,q->read_buf);
 658                 kfree(q->read_buf);
 659                 q->read_buf = NULL;
 660                 retval = -EIO;
 661                 goto done;
 662         }
 663
 664         /* Copy to userspace */
 665         retval=CALL(q,copy_to_user,q,data,count,nonblocking);
 666         if (retval<0)
 667                 goto done;
 668
 669         q->read_off += retval;
 670         if (q->read_off == q->read_buf->size) {
 671                 /* all data copied, cleanup */
 672                 q->ops->buf_release(q,q->read_buf);
 673                 kfree(q->read_buf);
 674                 q->read_buf = NULL;
 675         }
 676
 677  done:
 678         mutex_unlock(&q->lock);
 679         return retval;
 680 }
 681
 682 int videobuf_read_start(struct videobuf_queue *q)
 683 {
 684         enum v4l2_field field;
 685         unsigned long flags=0;
 686         int count = 0, size = 0;
 687         int err, i;
 688
 689         q->ops->buf_setup(q,&count,&size);
 690         if (count < 2)
 691                 count = 2;
 692         if (count > VIDEO_MAX_FRAME)
 693                 count = VIDEO_MAX_FRAME;
 694         size = PAGE_ALIGN(size);
 695
 696         err = videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
 697         if (err)
 698                 return err;
 699
 700         for (i = 0; i < count; i++) {
 701                 field = videobuf_next_field(q);
 702                 err = q->ops->buf_prepare(q,q->bufs[i],field);
 703                 if (err)
 704                         return err;
 705                 list_add_tail(&q->bufs[i]->stream, &q->stream);
 706         }
 707         if (q->irqlock)
 708                 spin_lock_irqsave(q->irqlock,flags);
 709         for (i = 0; i < count; i++)
 710                 q->ops->buf_queue(q,q->bufs[i]);
 711         if (q->irqlock)
 712                 spin_unlock_irqrestore(q->irqlock,flags);
 713         q->reading = 1;
 714         return 0;
 715 }
 716
 717 void videobuf_read_stop(struct videobuf_queue *q)
 718 {
 719         int i;
 720
 721         videobuf_queue_cancel(q);
 722         videobuf_mmap_free(q);
 723         INIT_LIST_HEAD(&q->stream);
 724         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 725                 if (NULL == q->bufs[i])
 726                         continue;
 727                 kfree(q->bufs[i]);
 728                 q->bufs[i] = NULL;
 729         }
 730         q->read_buf = NULL;
 731         q->reading  = 0;
 732 }
 733
 734 ssize_t videobuf_read_stream(struct videobuf_queue *q,
 735                              char __user *data, size_t count, loff_t *ppos,
 736                              int vbihack, int nonblocking)
 737 {
 738         int rc, retval;
 739         unsigned long flags=0;
 740
 741         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 742
 743         dprintk(2,"%s\n",__FUNCTION__);
 744         mutex_lock(&q->lock);
 745         retval = -EBUSY;
 746         if (q->streaming)
 747                 goto done;
 748         if (!q->reading) {
 749                 retval = videobuf_read_start(q);
 750                 if (retval < 0)
 751                         goto done;
 752         }
 753
 754         retval = 0;
 755         while (count > 0) {
 756                 /* get / wait for data */
 757                 if (NULL == q->read_buf) {
 758                         q->read_buf = list_entry(q->stream.next,
 759                                                  struct videobuf_buffer,
 760                                                  stream);
 761                         list_del(&q->read_buf->stream);
 762                         q->read_off = 0;
 763                 }
 764                 rc = videobuf_waiton(q->read_buf, nonblocking, 1);
 765                 if (rc < 0) {
 766                         if (0 == retval)
 767                                 retval = rc;
 768                         break;
 769                 }
 770
 771                 if (q->read_buf->state == STATE_DONE) {
 772                         rc = CALL (q,copy_stream, q, data, count,
 773                                         retval, vbihack, nonblocking);
 774                         if (rc < 0) {
 775                                 retval = rc;
 776                                 break;
 777                         }
 778                         retval      += rc;
 779                         count       -= rc;
 780                         q->read_off += rc;
 781                 } else {
 782                         /* some error */
 783                         q->read_off = q->read_buf->size;
 784                         if (0 == retval)
 785                                 retval = -EIO;
 786                 }
 787
 788                 /* requeue buffer when done with copying */
 789                 if (q->read_off == q->read_buf->size) {
 790                         list_add_tail(&q->read_buf->stream,
 791                                       &q->stream);
 792                         if (q->irqlock)
 793                                 spin_lock_irqsave(q->irqlock,flags);
 794                         q->ops->buf_queue(q,q->read_buf);
 795                         if (q->irqlock)
 796                                 spin_unlock_irqrestore(q->irqlock,flags);
 797                         q->read_buf = NULL;
 798                 }
 799                 if (retval < 0)
 800                         break;
 801         }
 802
 803  done:
 804         mutex_unlock(&q->lock);
 805         return retval;
 806 }
 807
 808 unsigned int videobuf_poll_stream(struct file *file,
 809                                   struct videobuf_queue *q,
 810                                   poll_table *wait)
 811 {
 812         struct videobuf_buffer *buf = NULL;
 813         unsigned int rc = 0;
 814
 815         mutex_lock(&q->lock);
 816         if (q->streaming) {
 817                 if (!list_empty(&q->stream))
 818                         buf = list_entry(q->stream.next,
 819                                          struct videobuf_buffer, stream);
 820         } else {
 821                 if (!q->reading)
 822                         videobuf_read_start(q);
 823                 if (!q->reading) {
 824                         rc = POLLERR;
 825                 } else if (NULL == q->read_buf) {
 826                         q->read_buf = list_entry(q->stream.next,
 827                                                  struct videobuf_buffer,
 828                                                  stream);
 829                         list_del(&q->read_buf->stream);
 830                         q->read_off = 0;
 831                 }
 832                 buf = q->read_buf;
 833         }
 834         if (!buf)
 835                 rc = POLLERR;
 836
 837         if (0 == rc) {
 838                 poll_wait(file, &buf->done, wait);
 839                 if (buf->state == STATE_DONE ||
 840                     buf->state == STATE_ERROR)
 841                         rc = POLLIN|POLLRDNORM;
 842         }
 843         mutex_unlock(&q->lock);
 844         return rc;
 845 }
 846
 847 int videobuf_mmap_setup(struct videobuf_queue *q,
 848                         unsigned int bcount, unsigned int bsize,
 849                         enum v4l2_memory memory)
 850 {
 851         unsigned int i;
 852         int err;
 853
 854         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 855
 856         err = videobuf_mmap_free(q);
 857         if (0 != err)
 858                 return err;
 859
 860         /* Allocate and initialize buffers */
 861         for (i = 0; i < bcount; i++) {
 862                 q->bufs[i] = videobuf_alloc(q);
 863
 864                 q->bufs[i]->i      = i;
 865                 q->bufs[i]->input  = UNSET;
 866                 q->bufs[i]->memory = memory;
 867                 q->bufs[i]->bsize  = bsize;
 868                 switch (memory) {
 869                 case V4L2_MEMORY_MMAP:
 870                         q->bufs[i]->boff  = bsize * i;
 871                         break;
 872                 case V4L2_MEMORY_USERPTR:
 873                 case V4L2_MEMORY_OVERLAY:
 874                         /* nothing */
 875                         break;
 876                 }
 877         }
 878
 879         dprintk(1,"mmap setup: %d buffers, %d bytes each\n",
 880                 bcount,bsize);
 881
 882         return 0;
 883 }
 884
 885 int videobuf_mmap_free(struct videobuf_queue *q)
 886 {
 887         int i;
 888         int rc;
 889
 890         if (!q)
 891                 return 0;
 892
 893         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 894
 895         rc  = CALL(q,mmap_free,q);
 896         if (rc<0)
 897                 return rc;
 898
 899         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 900                 if (NULL == q->bufs[i])
 901                         continue;
 902                 q->ops->buf_release(q,q->bufs[i]);
 903                 kfree(q->bufs[i]);
 904                 q->bufs[i] = NULL;
 905         }
 906
 907         return rc;
 908 }
 909
 910 int videobuf_mmap_mapper(struct videobuf_queue *q,
 911                          struct vm_area_struct *vma)
 912 {
 913         int retval;
 914
 915         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 916
 917         mutex_lock(&q->lock);
 918         retval=CALL(q,mmap_mapper,q,vma);
 919         mutex_unlock(&q->lock);
 920
 921         return retval;
 922 }
 923
 924 #ifdef CONFIG_VIDEO_V4L1_COMPAT
 925 int videobuf_cgmbuf(struct videobuf_queue *q,
 926                     struct video_mbuf *mbuf, int count)
 927 {
 928         struct v4l2_requestbuffers req;
 929         int rc,i;
 930
 931         MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
 932
 933         memset(&req,0,sizeof(req));
 934         req.type   = q->type;
 935         req.count  = count;
 936         req.memory = V4L2_MEMORY_MMAP;
 937         rc = videobuf_reqbufs(q,&req);
 938         if (rc < 0)
 939                 return rc;
 940
 941         mbuf->frames = req.count;
 942         mbuf->size   = 0;
 943         for (i = 0; i < mbuf->frames; i++) {
 944                 mbuf->offsets[i]  = q->bufs[i]->boff;
 945                 mbuf->size       += q->bufs[i]->bsize;
 946         }
 947
 948         return 0;
 949 }
 950 #endif
 951
 952 /* --------------------------------------------------------------------- */
 953
 954 EXPORT_SYMBOL_GPL(videobuf_waiton);
 955 EXPORT_SYMBOL_GPL(videobuf_iolock);
 956
 957 EXPORT_SYMBOL_GPL(videobuf_alloc);
 958
 959 EXPORT_SYMBOL_GPL(videobuf_queue_init);
 960 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
 961 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
 962
 963 EXPORT_SYMBOL_GPL(videobuf_next_field);
 964 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
 965 EXPORT_SYMBOL_GPL(videobuf_querybuf);
 966 EXPORT_SYMBOL_GPL(videobuf_qbuf);
 967 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
 968 EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
 969 EXPORT_SYMBOL_GPL(videobuf_streamon);
 970 EXPORT_SYMBOL_GPL(videobuf_streamoff);
 971
 972 EXPORT_SYMBOL_GPL(videobuf_read_start);
 973 EXPORT_SYMBOL_GPL(videobuf_read_stop);
 974 EXPORT_SYMBOL_GPL(videobuf_read_stream);
 975 EXPORT_SYMBOL_GPL(videobuf_read_one);
 976 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
 977
 978 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
 979 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
 980 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
 981
 982 /*
 983  * Local variables:
 984  * c-basic-offset: 8
 985  * End:
 986  */