git.oblomov.eu Git - 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/mm.h>
  20 #include <linux/slab.h>
  21 #include <linux/interrupt.h>
  22
  23 #include <media/videobuf-core.h>
  24
  25 #define MAGIC_BUFFER 0x20070728
  26 #define MAGIC_CHECK(is, should) do {                                       \
  27         if (unlikely((is) != (should))) {                                  \
  28         printk(KERN_ERR "magic mismatch: %x (expected %x)\n", is, should); \
  29         BUG(); } } while (0)
  30
  31 static int debug;
  32 module_param(debug, int, 0644);
  33
  34 MODULE_DESCRIPTION("helper module to manage video4linux buffers");
  35 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
  36 MODULE_LICENSE("GPL");
  37
  38 #define dprintk(level, fmt, arg...) do {                        \
  39         if (debug >= level)                                     \
  40         printk(KERN_DEBUG "vbuf: " fmt , ## arg); } while (0)
  41
  42 /* --------------------------------------------------------------------- */
  43
  44 #define CALL(q, f, arg...)                                              \
  45         ((q->int_ops->f) ? q->int_ops->f(arg) : 0)
  46
  47 void *videobuf_alloc(struct videobuf_queue *q)
  48 {
  49         struct videobuf_buffer *vb;
  50
  51         BUG_ON(q->msize < sizeof(*vb));
  52
  53         if (!q->int_ops || !q->int_ops->alloc) {
  54                 printk(KERN_ERR "No specific ops defined!\n");
  55                 BUG();
  56         }
  57
  58         vb = q->int_ops->alloc(q->msize);
  59
  60         if (NULL != vb) {
  61                 init_waitqueue_head(&vb->done);
  62                 vb->magic     = MAGIC_BUFFER;
  63         }
  64
  65         return vb;
  66 }
  67
  68 #define WAITON_CONDITION (vb->state != VIDEOBUF_ACTIVE &&\
  69                                 vb->state != VIDEOBUF_QUEUED)
  70 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
  71 {
  72         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
  73
  74         if (non_blocking) {
  75                 if (WAITON_CONDITION)
  76                         return 0;
  77                 else
  78                         return -EAGAIN;
  79         }
  80
  81         if (intr)
  82                 return wait_event_interruptible(vb->done, WAITON_CONDITION);
  83         else
  84                 wait_event(vb->done, WAITON_CONDITION);
  85
  86         return 0;
  87 }
  88
  89 int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
  90                     struct v4l2_framebuffer *fbuf)
  91 {
  92         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
  93         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
  94
  95         return CALL(q, iolock, q, vb, fbuf);
  96 }
  97
  98 void *videobuf_queue_to_vmalloc (struct videobuf_queue *q,
  99                            struct videobuf_buffer *buf)
 100 {
 101         if (q->int_ops->vmalloc)
 102                 return q->int_ops->vmalloc(buf);
 103         else
 104                 return NULL;
 105 }
 106 EXPORT_SYMBOL_GPL(videobuf_queue_to_vmalloc);
 107
 108 /* --------------------------------------------------------------------- */
 109
 110
 111 void videobuf_queue_core_init(struct videobuf_queue *q,
 112                          struct videobuf_queue_ops *ops,
 113                          struct device *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         BUG_ON(!q);
 122         memset(q, 0, sizeof(*q));
 123         q->irqlock   = irqlock;
 124         q->dev       = dev;
 125         q->type      = type;
 126         q->field     = field;
 127         q->msize     = msize;
 128         q->ops       = ops;
 129         q->priv_data = priv;
 130         q->int_ops   = int_ops;
 131
 132         /* All buffer operations are mandatory */
 133         BUG_ON(!q->ops->buf_setup);
 134         BUG_ON(!q->ops->buf_prepare);
 135         BUG_ON(!q->ops->buf_queue);
 136         BUG_ON(!q->ops->buf_release);
 137
 138         /* Lock is mandatory for queue_cancel to work */
 139         BUG_ON(!irqlock);
 140
 141         /* Having implementations for abstract methods are mandatory */
 142         BUG_ON(!q->int_ops);
 143
 144         mutex_init(&q->vb_lock);
 145         init_waitqueue_head(&q->wait);
 146         INIT_LIST_HEAD(&q->stream);
 147 }
 148
 149 /* Locking: Only usage in bttv unsafe find way to remove */
 150 int videobuf_queue_is_busy(struct videobuf_queue *q)
 151 {
 152         int i;
 153
 154         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 155
 156         if (q->streaming) {
 157                 dprintk(1, "busy: streaming active\n");
 158                 return 1;
 159         }
 160         if (q->reading) {
 161                 dprintk(1, "busy: pending read #1\n");
 162                 return 1;
 163         }
 164         if (q->read_buf) {
 165                 dprintk(1, "busy: pending read #2\n");
 166                 return 1;
 167         }
 168         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 169                 if (NULL == q->bufs[i])
 170                         continue;
 171                 if (q->bufs[i]->map) {
 172                         dprintk(1, "busy: buffer #%d mapped\n", i);
 173                         return 1;
 174                 }
 175                 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
 176                         dprintk(1, "busy: buffer #%d queued\n", i);
 177                         return 1;
 178                 }
 179                 if (q->bufs[i]->state == VIDEOBUF_ACTIVE) {
 180                         dprintk(1, "busy: buffer #%d avtive\n", i);
 181                         return 1;
 182                 }
 183         }
 184         return 0;
 185 }
 186
 187 /* Locking: Caller holds q->vb_lock */
 188 void videobuf_queue_cancel(struct videobuf_queue *q)
 189 {
 190         unsigned long flags = 0;
 191         int i;
 192
 193         q->streaming = 0;
 194         q->reading  = 0;
 195         wake_up_interruptible_sync(&q->wait);
 196
 197         /* remove queued buffers from list */
 198         spin_lock_irqsave(q->irqlock, flags);
 199         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 200                 if (NULL == q->bufs[i])
 201                         continue;
 202                 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
 203                         list_del(&q->bufs[i]->queue);
 204                         q->bufs[i]->state = VIDEOBUF_ERROR;
 205                         wake_up_all(&q->bufs[i]->done);
 206                 }
 207         }
 208         spin_unlock_irqrestore(q->irqlock, flags);
 209
 210         /* free all buffers + clear queue */
 211         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 212                 if (NULL == q->bufs[i])
 213                         continue;
 214                 q->ops->buf_release(q, q->bufs[i]);
 215         }
 216         INIT_LIST_HEAD(&q->stream);
 217 }
 218
 219 /* --------------------------------------------------------------------- */
 220
 221 /* Locking: Caller holds q->vb_lock */
 222 enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
 223 {
 224         enum v4l2_field field = q->field;
 225
 226         BUG_ON(V4L2_FIELD_ANY == field);
 227
 228         if (V4L2_FIELD_ALTERNATE == field) {
 229                 if (V4L2_FIELD_TOP == q->last) {
 230                         field   = V4L2_FIELD_BOTTOM;
 231                         q->last = V4L2_FIELD_BOTTOM;
 232                 } else {
 233                         field   = V4L2_FIELD_TOP;
 234                         q->last = V4L2_FIELD_TOP;
 235                 }
 236         }
 237         return field;
 238 }
 239
 240 /* Locking: Caller holds q->vb_lock */
 241 static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
 242                             struct videobuf_buffer *vb, enum v4l2_buf_type type)
 243 {
 244         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
 245         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 246
 247         b->index    = vb->i;
 248         b->type     = type;
 249
 250         b->memory   = vb->memory;
 251         switch (b->memory) {
 252         case V4L2_MEMORY_MMAP:
 253                 b->m.offset  = vb->boff;
 254                 b->length    = vb->bsize;
 255                 break;
 256         case V4L2_MEMORY_USERPTR:
 257                 b->m.userptr = vb->baddr;
 258                 b->length    = vb->bsize;
 259                 break;
 260         case V4L2_MEMORY_OVERLAY:
 261                 b->m.offset  = vb->boff;
 262                 break;
 263         }
 264
 265         b->flags    = 0;
 266         if (vb->map)
 267                 b->flags |= V4L2_BUF_FLAG_MAPPED;
 268
 269         switch (vb->state) {
 270         case VIDEOBUF_PREPARED:
 271         case VIDEOBUF_QUEUED:
 272         case VIDEOBUF_ACTIVE:
 273                 b->flags |= V4L2_BUF_FLAG_QUEUED;
 274                 break;
 275         case VIDEOBUF_DONE:
 276         case VIDEOBUF_ERROR:
 277                 b->flags |= V4L2_BUF_FLAG_DONE;
 278                 break;
 279         case VIDEOBUF_NEEDS_INIT:
 280         case VIDEOBUF_IDLE:
 281                 /* nothing */
 282                 break;
 283         }
 284
 285         if (vb->input != UNSET) {
 286                 b->flags |= V4L2_BUF_FLAG_INPUT;
 287                 b->input  = vb->input;
 288         }
 289
 290         b->field     = vb->field;
 291         b->timestamp = vb->ts;
 292         b->bytesused = vb->size;
 293         b->sequence  = vb->field_count >> 1;
 294 }
 295
 296 /* Locking: Caller holds q->vb_lock */
 297 static int __videobuf_mmap_free(struct videobuf_queue *q)
 298 {
 299         int i;
 300         int rc;
 301
 302         if (!q)
 303                 return 0;
 304
 305         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 306
 307
 308         rc  = CALL(q, mmap_free, q);
 309
 310         q->is_mmapped = 0;
 311
 312         if (rc < 0)
 313                 return rc;
 314
 315         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 316                 if (NULL == q->bufs[i])
 317                         continue;
 318                 q->ops->buf_release(q, q->bufs[i]);
 319                 kfree(q->bufs[i]);
 320                 q->bufs[i] = NULL;
 321         }
 322
 323         return rc;
 324 }
 325
 326 int videobuf_mmap_free(struct videobuf_queue *q)
 327 {
 328         int ret;
 329         mutex_lock(&q->vb_lock);
 330         ret = __videobuf_mmap_free(q);
 331         mutex_unlock(&q->vb_lock);
 332         return ret;
 333 }
 334
 335 /* Locking: Caller holds q->vb_lock */
 336 int __videobuf_mmap_setup(struct videobuf_queue *q,
 337                         unsigned int bcount, unsigned int bsize,
 338                         enum v4l2_memory memory)
 339 {
 340         unsigned int i;
 341         int err;
 342
 343         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 344
 345         err = __videobuf_mmap_free(q);
 346         if (0 != err)
 347                 return err;
 348
 349         /* Allocate and initialize buffers */
 350         for (i = 0; i < bcount; i++) {
 351                 q->bufs[i] = videobuf_alloc(q);
 352
 353                 if (q->bufs[i] == NULL)
 354                         break;
 355
 356                 q->bufs[i]->i      = i;
 357                 q->bufs[i]->input  = UNSET;
 358                 q->bufs[i]->memory = memory;
 359                 q->bufs[i]->bsize  = bsize;
 360                 switch (memory) {
 361                 case V4L2_MEMORY_MMAP:
 362                         q->bufs[i]->boff  = bsize * i;
 363                         break;
 364                 case V4L2_MEMORY_USERPTR:
 365                 case V4L2_MEMORY_OVERLAY:
 366                         /* nothing */
 367                         break;
 368                 }
 369         }
 370
 371         if (!i)
 372                 return -ENOMEM;
 373
 374         dprintk(1, "mmap setup: %d buffers, %d bytes each\n",
 375                 i, bsize);
 376
 377         return i;
 378 }
 379
 380 int videobuf_mmap_setup(struct videobuf_queue *q,
 381                         unsigned int bcount, unsigned int bsize,
 382                         enum v4l2_memory memory)
 383 {
 384         int ret;
 385         mutex_lock(&q->vb_lock);
 386         ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
 387         mutex_unlock(&q->vb_lock);
 388         return ret;
 389 }
 390
 391 int videobuf_reqbufs(struct videobuf_queue *q,
 392                  struct v4l2_requestbuffers *req)
 393 {
 394         unsigned int size, count;
 395         int retval;
 396
 397         if (req->count < 1) {
 398                 dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
 399                 return -EINVAL;
 400         }
 401
 402         if (req->memory != V4L2_MEMORY_MMAP     &&
 403             req->memory != V4L2_MEMORY_USERPTR  &&
 404             req->memory != V4L2_MEMORY_OVERLAY) {
 405                 dprintk(1, "reqbufs: memory type invalid\n");
 406                 return -EINVAL;
 407         }
 408
 409         mutex_lock(&q->vb_lock);
 410         if (req->type != q->type) {
 411                 dprintk(1, "reqbufs: queue type invalid\n");
 412                 retval = -EINVAL;
 413                 goto done;
 414         }
 415
 416         if (q->streaming) {
 417                 dprintk(1, "reqbufs: streaming already exists\n");
 418                 retval = -EBUSY;
 419                 goto done;
 420         }
 421         if (!list_empty(&q->stream)) {
 422                 dprintk(1, "reqbufs: stream running\n");
 423                 retval = -EBUSY;
 424                 goto done;
 425         }
 426
 427         count = req->count;
 428         if (count > VIDEO_MAX_FRAME)
 429                 count = VIDEO_MAX_FRAME;
 430         size = 0;
 431         q->ops->buf_setup(q, &count, &size);
 432         size = PAGE_ALIGN(size);
 433         dprintk(1, "reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
 434                 count, size, (count*size)>>PAGE_SHIFT);
 435
 436         retval = __videobuf_mmap_setup(q, count, size, req->memory);
 437         if (retval < 0) {
 438                 dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
 439                 goto done;
 440         }
 441
 442         req->count = retval;
 443         retval = 0;
 444
 445  done:
 446         mutex_unlock(&q->vb_lock);
 447         return retval;
 448 }
 449
 450 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 451 {
 452         int ret = -EINVAL;
 453
 454         mutex_lock(&q->vb_lock);
 455         if (unlikely(b->type != q->type)) {
 456                 dprintk(1, "querybuf: Wrong type.\n");
 457                 goto done;
 458         }
 459         if (unlikely(b->index >= VIDEO_MAX_FRAME)) {
 460                 dprintk(1, "querybuf: index out of range.\n");
 461                 goto done;
 462         }
 463         if (unlikely(NULL == q->bufs[b->index])) {
 464                 dprintk(1, "querybuf: buffer is null.\n");
 465                 goto done;
 466         }
 467
 468         videobuf_status(q, b, q->bufs[b->index], q->type);
 469
 470         ret = 0;
 471 done:
 472         mutex_unlock(&q->vb_lock);
 473         return ret;
 474 }
 475
 476 int videobuf_qbuf(struct videobuf_queue *q,
 477               struct v4l2_buffer *b)
 478 {
 479         struct videobuf_buffer *buf;
 480         enum v4l2_field field;
 481         unsigned long flags = 0;
 482         int retval;
 483
 484         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 485
 486         if (b->memory == V4L2_MEMORY_MMAP)
 487                 down_read(&current->mm->mmap_sem);
 488
 489         mutex_lock(&q->vb_lock);
 490         retval = -EBUSY;
 491         if (q->reading) {
 492                 dprintk(1, "qbuf: Reading running...\n");
 493                 goto done;
 494         }
 495         retval = -EINVAL;
 496         if (b->type != q->type) {
 497                 dprintk(1, "qbuf: Wrong type.\n");
 498                 goto done;
 499         }
 500         if (b->index >= VIDEO_MAX_FRAME) {
 501                 dprintk(1, "qbuf: index out of range.\n");
 502                 goto done;
 503         }
 504         buf = q->bufs[b->index];
 505         if (NULL == buf) {
 506                 dprintk(1, "qbuf: buffer is null.\n");
 507                 goto done;
 508         }
 509         MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
 510         if (buf->memory != b->memory) {
 511                 dprintk(1, "qbuf: memory type is wrong.\n");
 512                 goto done;
 513         }
 514         if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
 515                 dprintk(1, "qbuf: buffer is already queued or active.\n");
 516                 goto done;
 517         }
 518
 519         if (b->flags & V4L2_BUF_FLAG_INPUT) {
 520                 if (b->input >= q->inputs) {
 521                         dprintk(1, "qbuf: wrong input.\n");
 522                         goto done;
 523                 }
 524                 buf->input = b->input;
 525         } else {
 526                 buf->input = UNSET;
 527         }
 528
 529         switch (b->memory) {
 530         case V4L2_MEMORY_MMAP:
 531                 if (0 == buf->baddr) {
 532                         dprintk(1, "qbuf: mmap requested "
 533                                    "but buffer addr is zero!\n");
 534                         goto done;
 535                 }
 536                 break;
 537         case V4L2_MEMORY_USERPTR:
 538                 if (b->length < buf->bsize) {
 539                         dprintk(1, "qbuf: buffer length is not enough\n");
 540                         goto done;
 541                 }
 542                 if (VIDEOBUF_NEEDS_INIT != buf->state &&
 543                     buf->baddr != b->m.userptr)
 544                         q->ops->buf_release(q, buf);
 545                 buf->baddr = b->m.userptr;
 546                 break;
 547         case V4L2_MEMORY_OVERLAY:
 548                 buf->boff = b->m.offset;
 549                 break;
 550         default:
 551                 dprintk(1, "qbuf: wrong memory type\n");
 552                 goto done;
 553         }
 554
 555         dprintk(1, "qbuf: requesting next field\n");
 556         field = videobuf_next_field(q);
 557         retval = q->ops->buf_prepare(q, buf, field);
 558         if (0 != retval) {
 559                 dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
 560                 goto done;
 561         }
 562
 563         list_add_tail(&buf->stream, &q->stream);
 564         if (q->streaming) {
 565                 spin_lock_irqsave(q->irqlock, flags);
 566                 q->ops->buf_queue(q, buf);
 567                 spin_unlock_irqrestore(q->irqlock, flags);
 568         }
 569         dprintk(1, "qbuf: succeded\n");
 570         retval = 0;
 571         wake_up_interruptible_sync(&q->wait);
 572
 573  done:
 574         mutex_unlock(&q->vb_lock);
 575
 576         if (b->memory == V4L2_MEMORY_MMAP)
 577                 up_read(&current->mm->mmap_sem);
 578
 579         return retval;
 580 }
 581
 582
 583 /* Locking: Caller holds q->vb_lock */
 584 static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
 585 {
 586         int retval;
 587
 588 checks:
 589         if (!q->streaming) {
 590                 dprintk(1, "next_buffer: Not streaming\n");
 591                 retval = -EINVAL;
 592                 goto done;
 593         }
 594
 595         if (list_empty(&q->stream)) {
 596                 if (noblock) {
 597                         retval = -EAGAIN;
 598                         dprintk(2, "next_buffer: no buffers to dequeue\n");
 599                         goto done;
 600                 } else {
 601                         dprintk(2, "next_buffer: waiting on buffer\n");
 602
 603                         /* Drop lock to avoid deadlock with qbuf */
 604                         mutex_unlock(&q->vb_lock);
 605
 606                         /* Checking list_empty and streaming is safe without
 607                          * locks because we goto checks to validate while
 608                          * holding locks before proceeding */
 609                         retval = wait_event_interruptible(q->wait,
 610                                 !list_empty(&q->stream) || !q->streaming);
 611                         mutex_lock(&q->vb_lock);
 612
 613                         if (retval)
 614                                 goto done;
 615
 616                         goto checks;
 617                 }
 618         }
 619
 620         retval = 0;
 621
 622 done:
 623         return retval;
 624 }
 625
 626
 627 /* Locking: Caller holds q->vb_lock */
 628 static int stream_next_buffer(struct videobuf_queue *q,
 629                         struct videobuf_buffer **vb, int nonblocking)
 630 {
 631         int retval;
 632         struct videobuf_buffer *buf = NULL;
 633
 634         retval = stream_next_buffer_check_queue(q, nonblocking);
 635         if (retval)
 636                 goto done;
 637
 638         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 639         retval = videobuf_waiton(buf, nonblocking, 1);
 640         if (retval < 0)
 641                 goto done;
 642
 643         *vb = buf;
 644 done:
 645         return retval;
 646 }
 647
 648 int videobuf_dqbuf(struct videobuf_queue *q,
 649                struct v4l2_buffer *b, int nonblocking)
 650 {
 651         struct videobuf_buffer *buf = NULL;
 652         int retval;
 653
 654         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 655
 656         mutex_lock(&q->vb_lock);
 657
 658         retval = stream_next_buffer(q, &buf, nonblocking);
 659         if (retval < 0) {
 660                 dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
 661                 goto done;
 662         }
 663
 664         switch (buf->state) {
 665         case VIDEOBUF_ERROR:
 666                 dprintk(1, "dqbuf: state is error\n");
 667                 retval = -EIO;
 668                 CALL(q, sync, q, buf);
 669                 buf->state = VIDEOBUF_IDLE;
 670                 break;
 671         case VIDEOBUF_DONE:
 672                 dprintk(1, "dqbuf: state is done\n");
 673                 CALL(q, sync, q, buf);
 674                 buf->state = VIDEOBUF_IDLE;
 675                 break;
 676         default:
 677                 dprintk(1, "dqbuf: state invalid\n");
 678                 retval = -EINVAL;
 679                 goto done;
 680         }
 681         list_del(&buf->stream);
 682         memset(b, 0, sizeof(*b));
 683         videobuf_status(q, b, buf, q->type);
 684
 685  done:
 686         mutex_unlock(&q->vb_lock);
 687         return retval;
 688 }
 689
 690 int videobuf_streamon(struct videobuf_queue *q)
 691 {
 692         struct videobuf_buffer *buf;
 693         unsigned long flags = 0;
 694         int retval;
 695
 696         mutex_lock(&q->vb_lock);
 697         retval = -EBUSY;
 698         if (q->reading)
 699                 goto done;
 700         retval = 0;
 701         if (q->streaming)
 702                 goto done;
 703         q->streaming = 1;
 704         spin_lock_irqsave(q->irqlock, flags);
 705         list_for_each_entry(buf, &q->stream, stream)
 706                 if (buf->state == VIDEOBUF_PREPARED)
 707                         q->ops->buf_queue(q, buf);
 708         spin_unlock_irqrestore(q->irqlock, flags);
 709
 710         wake_up_interruptible_sync(&q->wait);
 711  done:
 712         mutex_unlock(&q->vb_lock);
 713         return retval;
 714 }
 715
 716 /* Locking: Caller holds q->vb_lock */
 717 static int __videobuf_streamoff(struct videobuf_queue *q)
 718 {
 719         if (!q->streaming)
 720                 return -EINVAL;
 721
 722         videobuf_queue_cancel(q);
 723
 724         return 0;
 725 }
 726
 727 int videobuf_streamoff(struct videobuf_queue *q)
 728 {
 729         int retval;
 730
 731         mutex_lock(&q->vb_lock);
 732         retval = __videobuf_streamoff(q);
 733         mutex_unlock(&q->vb_lock);
 734
 735         return retval;
 736 }
 737
 738 /* Locking: Caller holds q->vb_lock */
 739 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
 740                                       char __user *data,
 741                                       size_t count, loff_t *ppos)
 742 {
 743         enum v4l2_field field;
 744         unsigned long flags = 0;
 745         int retval;
 746
 747         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 748
 749         /* setup stuff */
 750         q->read_buf = videobuf_alloc(q);
 751         if (NULL == q->read_buf)
 752                 return -ENOMEM;
 753
 754         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 755         q->read_buf->baddr  = (unsigned long)data;
 756         q->read_buf->bsize  = count;
 757
 758         field = videobuf_next_field(q);
 759         retval = q->ops->buf_prepare(q, q->read_buf, field);
 760         if (0 != retval)
 761                 goto done;
 762
 763         /* start capture & wait */
 764         spin_lock_irqsave(q->irqlock, flags);
 765         q->ops->buf_queue(q, q->read_buf);
 766         spin_unlock_irqrestore(q->irqlock, flags);
 767         retval = videobuf_waiton(q->read_buf, 0, 0);
 768         if (0 == retval) {
 769                 CALL(q, sync, q, q->read_buf);
 770                 if (VIDEOBUF_ERROR == q->read_buf->state)
 771                         retval = -EIO;
 772                 else
 773                         retval = q->read_buf->size;
 774         }
 775
 776  done:
 777         /* cleanup */
 778         q->ops->buf_release(q, q->read_buf);
 779         kfree(q->read_buf);
 780         q->read_buf = NULL;
 781         return retval;
 782 }
 783
 784 ssize_t videobuf_read_one(struct videobuf_queue *q,
 785                           char __user *data, size_t count, loff_t *ppos,
 786                           int nonblocking)
 787 {
 788         enum v4l2_field field;
 789         unsigned long flags = 0;
 790         unsigned size = 0, nbufs = 1;
 791         int retval;
 792
 793         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 794
 795         mutex_lock(&q->vb_lock);
 796
 797         q->ops->buf_setup(q, &nbufs, &size);
 798
 799         if (NULL == q->read_buf  &&
 800             count >= size        &&
 801             !nonblocking) {
 802                 retval = videobuf_read_zerocopy(q, data, count, ppos);
 803                 if (retval >= 0  ||  retval == -EIO)
 804                         /* ok, all done */
 805                         goto done;
 806                 /* fallback to kernel bounce buffer on failures */
 807         }
 808
 809         if (NULL == q->read_buf) {
 810                 /* need to capture a new frame */
 811                 retval = -ENOMEM;
 812                 q->read_buf = videobuf_alloc(q);
 813
 814                 dprintk(1, "video alloc=0x%p\n", q->read_buf);
 815                 if (NULL == q->read_buf)
 816                         goto done;
 817                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 818                 q->read_buf->bsize = count; /* preferred size */
 819                 field = videobuf_next_field(q);
 820                 retval = q->ops->buf_prepare(q, q->read_buf, field);
 821
 822                 if (0 != retval) {
 823                         kfree(q->read_buf);
 824                         q->read_buf = NULL;
 825                         goto done;
 826                 }
 827
 828                 spin_lock_irqsave(q->irqlock, flags);
 829                 q->ops->buf_queue(q, q->read_buf);
 830                 spin_unlock_irqrestore(q->irqlock, flags);
 831
 832                 q->read_off = 0;
 833         }
 834
 835         /* wait until capture is done */
 836         retval = videobuf_waiton(q->read_buf, nonblocking, 1);
 837         if (0 != retval)
 838                 goto done;
 839
 840         CALL(q, sync, q, q->read_buf);
 841
 842         if (VIDEOBUF_ERROR == q->read_buf->state) {
 843                 /* catch I/O errors */
 844                 q->ops->buf_release(q, q->read_buf);
 845                 kfree(q->read_buf);
 846                 q->read_buf = NULL;
 847                 retval = -EIO;
 848                 goto done;
 849         }
 850
 851         /* Copy to userspace */
 852         retval = CALL(q, video_copy_to_user, q, data, count, nonblocking);
 853         if (retval < 0)
 854                 goto done;
 855
 856         q->read_off += retval;
 857         if (q->read_off == q->read_buf->size) {
 858                 /* all data copied, cleanup */
 859                 q->ops->buf_release(q, q->read_buf);
 860                 kfree(q->read_buf);
 861                 q->read_buf = NULL;
 862         }
 863
 864  done:
 865         mutex_unlock(&q->vb_lock);
 866         return retval;
 867 }
 868
 869 /* Locking: Caller holds q->vb_lock */
 870 static int __videobuf_read_start(struct videobuf_queue *q)
 871 {
 872         enum v4l2_field field;
 873         unsigned long flags = 0;
 874         unsigned int count = 0, size = 0;
 875         int err, i;
 876
 877         q->ops->buf_setup(q, &count, &size);
 878         if (count < 2)
 879                 count = 2;
 880         if (count > VIDEO_MAX_FRAME)
 881                 count = VIDEO_MAX_FRAME;
 882         size = PAGE_ALIGN(size);
 883
 884         err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
 885         if (err < 0)
 886                 return err;
 887
 888         count = err;
 889
 890         for (i = 0; i < count; i++) {
 891                 field = videobuf_next_field(q);
 892                 err = q->ops->buf_prepare(q, q->bufs[i], field);
 893                 if (err)
 894                         return err;
 895                 list_add_tail(&q->bufs[i]->stream, &q->stream);
 896         }
 897         spin_lock_irqsave(q->irqlock, flags);
 898         for (i = 0; i < count; i++)
 899                 q->ops->buf_queue(q, q->bufs[i]);
 900         spin_unlock_irqrestore(q->irqlock, flags);
 901         q->reading = 1;
 902         return 0;
 903 }
 904
 905 static void __videobuf_read_stop(struct videobuf_queue *q)
 906 {
 907         int i;
 908
 909         videobuf_queue_cancel(q);
 910         __videobuf_mmap_free(q);
 911         INIT_LIST_HEAD(&q->stream);
 912         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 913                 if (NULL == q->bufs[i])
 914                         continue;
 915                 kfree(q->bufs[i]);
 916                 q->bufs[i] = NULL;
 917         }
 918         q->read_buf = NULL;
 919
 920 }
 921
 922 int videobuf_read_start(struct videobuf_queue *q)
 923 {
 924         int rc;
 925
 926         mutex_lock(&q->vb_lock);
 927         rc = __videobuf_read_start(q);
 928         mutex_unlock(&q->vb_lock);
 929
 930         return rc;
 931 }
 932
 933 void videobuf_read_stop(struct videobuf_queue *q)
 934 {
 935         mutex_lock(&q->vb_lock);
 936         __videobuf_read_stop(q);
 937         mutex_unlock(&q->vb_lock);
 938 }
 939
 940 void videobuf_stop(struct videobuf_queue *q)
 941 {
 942         mutex_lock(&q->vb_lock);
 943
 944         if (q->streaming)
 945                 __videobuf_streamoff(q);
 946
 947         if (q->reading)
 948                 __videobuf_read_stop(q);
 949
 950         mutex_unlock(&q->vb_lock);
 951 }
 952
 953
 954 ssize_t videobuf_read_stream(struct videobuf_queue *q,
 955                              char __user *data, size_t count, loff_t *ppos,
 956                              int vbihack, int nonblocking)
 957 {
 958         int rc, retval;
 959         unsigned long flags = 0;
 960
 961         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 962
 963         dprintk(2, "%s\n", __func__);
 964         mutex_lock(&q->vb_lock);
 965         retval = -EBUSY;
 966         if (q->streaming)
 967                 goto done;
 968         if (!q->reading) {
 969                 retval = __videobuf_read_start(q);
 970                 if (retval < 0)
 971                         goto done;
 972         }
 973
 974         retval = 0;
 975         while (count > 0) {
 976                 /* get / wait for data */
 977                 if (NULL == q->read_buf) {
 978                         q->read_buf = list_entry(q->stream.next,
 979                                                  struct videobuf_buffer,
 980                                                  stream);
 981                         list_del(&q->read_buf->stream);
 982                         q->read_off = 0;
 983                 }
 984                 rc = videobuf_waiton(q->read_buf, nonblocking, 1);
 985                 if (rc < 0) {
 986                         if (0 == retval)
 987                                 retval = rc;
 988                         break;
 989                 }
 990
 991                 if (q->read_buf->state == VIDEOBUF_DONE) {
 992                         rc = CALL(q, copy_stream, q, data + retval, count,
 993                                         retval, vbihack, nonblocking);
 994                         if (rc < 0) {
 995                                 retval = rc;
 996                                 break;
 997                         }
 998                         retval      += rc;
 999                         count       -= rc;
1000                         q->read_off += rc;
1001                 } else {
1002                         /* some error */
1003                         q->read_off = q->read_buf->size;
1004                         if (0 == retval)
1005                                 retval = -EIO;
1006                 }
1007
1008                 /* requeue buffer when done with copying */
1009                 if (q->read_off == q->read_buf->size) {
1010                         list_add_tail(&q->read_buf->stream,
1011                                       &q->stream);
1012                         spin_lock_irqsave(q->irqlock, flags);
1013                         q->ops->buf_queue(q, q->read_buf);
1014                         spin_unlock_irqrestore(q->irqlock, flags);
1015                         q->read_buf = NULL;
1016                 }
1017                 if (retval < 0)
1018                         break;
1019         }
1020
1021  done:
1022         mutex_unlock(&q->vb_lock);
1023         return retval;
1024 }
1025
1026 unsigned int videobuf_poll_stream(struct file *file,
1027                                   struct videobuf_queue *q,
1028                                   poll_table *wait)
1029 {
1030         struct videobuf_buffer *buf = NULL;
1031         unsigned int rc = 0;
1032
1033         mutex_lock(&q->vb_lock);
1034         if (q->streaming) {
1035                 if (!list_empty(&q->stream))
1036                         buf = list_entry(q->stream.next,
1037                                          struct videobuf_buffer, stream);
1038         } else {
1039                 if (!q->reading)
1040                         __videobuf_read_start(q);
1041                 if (!q->reading) {
1042                         rc = POLLERR;
1043                 } else if (NULL == q->read_buf) {
1044                         q->read_buf = list_entry(q->stream.next,
1045                                                  struct videobuf_buffer,
1046                                                  stream);
1047                         list_del(&q->read_buf->stream);
1048                         q->read_off = 0;
1049                 }
1050                 buf = q->read_buf;
1051         }
1052         if (!buf)
1053                 rc = POLLERR;
1054
1055         if (0 == rc) {
1056                 poll_wait(file, &buf->done, wait);
1057                 if (buf->state == VIDEOBUF_DONE ||
1058                     buf->state == VIDEOBUF_ERROR)
1059                         rc = POLLIN|POLLRDNORM;
1060         }
1061         mutex_unlock(&q->vb_lock);
1062         return rc;
1063 }
1064
1065 int videobuf_mmap_mapper(struct videobuf_queue *q,
1066                          struct vm_area_struct *vma)
1067 {
1068         int retval;
1069
1070         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1071
1072         mutex_lock(&q->vb_lock);
1073         retval = CALL(q, mmap_mapper, q, vma);
1074         q->is_mmapped = 1;
1075         mutex_unlock(&q->vb_lock);
1076
1077         return retval;
1078 }
1079
1080 #ifdef CONFIG_VIDEO_V4L1_COMPAT
1081 int videobuf_cgmbuf(struct videobuf_queue *q,
1082                     struct video_mbuf *mbuf, int count)
1083 {
1084         struct v4l2_requestbuffers req;
1085         int rc, i;
1086
1087         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1088
1089         memset(&req, 0, sizeof(req));
1090         req.type   = q->type;
1091         req.count  = count;
1092         req.memory = V4L2_MEMORY_MMAP;
1093         rc = videobuf_reqbufs(q, &req);
1094         if (rc < 0)
1095                 return rc;
1096
1097         mbuf->frames = req.count;
1098         mbuf->size   = 0;
1099         for (i = 0; i < mbuf->frames; i++) {
1100                 mbuf->offsets[i]  = q->bufs[i]->boff;
1101                 mbuf->size       += q->bufs[i]->bsize;
1102         }
1103
1104         return 0;
1105 }
1106 EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
1107 #endif
1108
1109 /* --------------------------------------------------------------------- */
1110
1111 EXPORT_SYMBOL_GPL(videobuf_waiton);
1112 EXPORT_SYMBOL_GPL(videobuf_iolock);
1113
1114 EXPORT_SYMBOL_GPL(videobuf_alloc);
1115
1116 EXPORT_SYMBOL_GPL(videobuf_queue_core_init);
1117 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
1118 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
1119
1120 EXPORT_SYMBOL_GPL(videobuf_next_field);
1121 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
1122 EXPORT_SYMBOL_GPL(videobuf_querybuf);
1123 EXPORT_SYMBOL_GPL(videobuf_qbuf);
1124 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
1125 EXPORT_SYMBOL_GPL(videobuf_streamon);
1126 EXPORT_SYMBOL_GPL(videobuf_streamoff);
1127
1128 EXPORT_SYMBOL_GPL(videobuf_read_start);
1129 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1130 EXPORT_SYMBOL_GPL(videobuf_stop);
1131 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1132 EXPORT_SYMBOL_GPL(videobuf_read_one);
1133 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1134
1135 EXPORT_SYMBOL_GPL(__videobuf_mmap_setup);
1136 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
1137 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
1138 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);