SAFE public projects git trees. - safe/jmp/linux-2.6/blob - drivers/media/video/videobuf-core.c

   1 /*
   2  * generic helper functions for handling video4linux capture buffers
   3  *
   4  * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org>
   5  *
   6  * Highly based on video-buf written originally by:
   7  * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
   8  * (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org>
   9  * (c) 2006 Ted Walther and John Sokol
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2
  14  */
  15
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/moduleparam.h>
  19 #include <linux/mm.h>
  20 #include <linux/sched.h>
  21 #include <linux/slab.h>
  22 #include <linux/interrupt.h>
  23
  24 #include <media/videobuf-core.h>
  25
  26 #define MAGIC_BUFFER 0x20070728
  27 #define MAGIC_CHECK(is, should)                                         \
  28         do {                                                            \
  29                 if (unlikely((is) != (should))) {                       \
  30                         printk(KERN_ERR                                 \
  31                                 "magic mismatch: %x (expected %x)\n",   \
  32                                         is, should);                    \
  33                         BUG();                                          \
  34                 }                                                       \
  35         } while (0)
  36
  37 static int debug;
  38 module_param(debug, int, 0644);
  39
  40 MODULE_DESCRIPTION("helper module to manage video4linux buffers");
  41 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
  42 MODULE_LICENSE("GPL");
  43
  44 #define dprintk(level, fmt, arg...)                                     \
  45         do {                                                            \
  46                 if (debug >= level)                                     \
  47                         printk(KERN_DEBUG "vbuf: " fmt, ## arg);        \
  48         } while (0)
  49
  50 /* --------------------------------------------------------------------- */
  51
  52 #define CALL(q, f, arg...)                                              \
  53         ((q->int_ops->f) ? q->int_ops->f(arg) : 0)
  54
  55 void *videobuf_alloc(struct videobuf_queue *q)
  56 {
  57         struct videobuf_buffer *vb;
  58
  59         BUG_ON(q->msize < sizeof(*vb));
  60
  61         if (!q->int_ops || !q->int_ops->alloc) {
  62                 printk(KERN_ERR "No specific ops defined!\n");
  63                 BUG();
  64         }
  65
  66         vb = q->int_ops->alloc(q->msize);
  67         if (NULL != vb) {
  68                 init_waitqueue_head(&vb->done);
  69                 vb->magic = MAGIC_BUFFER;
  70         }
  71
  72         return vb;
  73 }
  74 EXPORT_SYMBOL_GPL(videobuf_alloc);
  75
  76 #define WAITON_CONDITION (vb->state != VIDEOBUF_ACTIVE &&\
  77                                 vb->state != VIDEOBUF_QUEUED)
  78 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
  79 {
  80         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
  81
  82         if (non_blocking) {
  83                 if (WAITON_CONDITION)
  84                         return 0;
  85                 else
  86                         return -EAGAIN;
  87         }
  88
  89         if (intr)
  90                 return wait_event_interruptible(vb->done, WAITON_CONDITION);
  91         else
  92                 wait_event(vb->done, WAITON_CONDITION);
  93
  94         return 0;
  95 }
  96 EXPORT_SYMBOL_GPL(videobuf_waiton);
  97
  98 int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
  99                     struct v4l2_framebuffer *fbuf)
 100 {
 101         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
 102         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 103
 104         return CALL(q, iolock, q, vb, fbuf);
 105 }
 106 EXPORT_SYMBOL_GPL(videobuf_iolock);
 107
 108 void *videobuf_queue_to_vmalloc(struct videobuf_queue *q,
 109                                 struct videobuf_buffer *buf)
 110 {
 111         if (q->int_ops->vmalloc)
 112                 return q->int_ops->vmalloc(buf);
 113         else
 114                 return NULL;
 115 }
 116 EXPORT_SYMBOL_GPL(videobuf_queue_to_vmalloc);
 117
 118 /* --------------------------------------------------------------------- */
 119
 120
 121 void videobuf_queue_core_init(struct videobuf_queue *q,
 122                          const struct videobuf_queue_ops *ops,
 123                          struct device *dev,
 124                          spinlock_t *irqlock,
 125                          enum v4l2_buf_type type,
 126                          enum v4l2_field field,
 127                          unsigned int msize,
 128                          void *priv,
 129                          struct videobuf_qtype_ops *int_ops)
 130 {
 131         BUG_ON(!q);
 132         memset(q, 0, sizeof(*q));
 133         q->irqlock   = irqlock;
 134         q->dev       = dev;
 135         q->type      = type;
 136         q->field     = field;
 137         q->msize     = msize;
 138         q->ops       = ops;
 139         q->priv_data = priv;
 140         q->int_ops   = int_ops;
 141
 142         /* All buffer operations are mandatory */
 143         BUG_ON(!q->ops->buf_setup);
 144         BUG_ON(!q->ops->buf_prepare);
 145         BUG_ON(!q->ops->buf_queue);
 146         BUG_ON(!q->ops->buf_release);
 147
 148         /* Lock is mandatory for queue_cancel to work */
 149         BUG_ON(!irqlock);
 150
 151         /* Having implementations for abstract methods are mandatory */
 152         BUG_ON(!q->int_ops);
 153
 154         mutex_init(&q->vb_lock);
 155         init_waitqueue_head(&q->wait);
 156         INIT_LIST_HEAD(&q->stream);
 157 }
 158 EXPORT_SYMBOL_GPL(videobuf_queue_core_init);
 159
 160 /* Locking: Only usage in bttv unsafe find way to remove */
 161 int videobuf_queue_is_busy(struct videobuf_queue *q)
 162 {
 163         int i;
 164
 165         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 166
 167         if (q->streaming) {
 168                 dprintk(1, "busy: streaming active\n");
 169                 return 1;
 170         }
 171         if (q->reading) {
 172                 dprintk(1, "busy: pending read #1\n");
 173                 return 1;
 174         }
 175         if (q->read_buf) {
 176                 dprintk(1, "busy: pending read #2\n");
 177                 return 1;
 178         }
 179         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 180                 if (NULL == q->bufs[i])
 181                         continue;
 182                 if (q->bufs[i]->map) {
 183                         dprintk(1, "busy: buffer #%d mapped\n", i);
 184                         return 1;
 185                 }
 186                 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
 187                         dprintk(1, "busy: buffer #%d queued\n", i);
 188                         return 1;
 189                 }
 190                 if (q->bufs[i]->state == VIDEOBUF_ACTIVE) {
 191                         dprintk(1, "busy: buffer #%d avtive\n", i);
 192                         return 1;
 193                 }
 194         }
 195         return 0;
 196 }
 197 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
 198
 199 /* Locking: Caller holds q->vb_lock */
 200 void videobuf_queue_cancel(struct videobuf_queue *q)
 201 {
 202         unsigned long flags = 0;
 203         int i;
 204
 205         q->streaming = 0;
 206         q->reading  = 0;
 207         wake_up_interruptible_sync(&q->wait);
 208
 209         /* remove queued buffers from list */
 210         spin_lock_irqsave(q->irqlock, flags);
 211         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 212                 if (NULL == q->bufs[i])
 213                         continue;
 214                 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
 215                         list_del(&q->bufs[i]->queue);
 216                         q->bufs[i]->state = VIDEOBUF_ERROR;
 217                         wake_up_all(&q->bufs[i]->done);
 218                 }
 219         }
 220         spin_unlock_irqrestore(q->irqlock, flags);
 221
 222         /* free all buffers + clear queue */
 223         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 224                 if (NULL == q->bufs[i])
 225                         continue;
 226                 q->ops->buf_release(q, q->bufs[i]);
 227         }
 228         INIT_LIST_HEAD(&q->stream);
 229 }
 230 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
 231
 232 /* --------------------------------------------------------------------- */
 233
 234 /* Locking: Caller holds q->vb_lock */
 235 enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
 236 {
 237         enum v4l2_field field = q->field;
 238
 239         BUG_ON(V4L2_FIELD_ANY == field);
 240
 241         if (V4L2_FIELD_ALTERNATE == field) {
 242                 if (V4L2_FIELD_TOP == q->last) {
 243                         field   = V4L2_FIELD_BOTTOM;
 244                         q->last = V4L2_FIELD_BOTTOM;
 245                 } else {
 246                         field   = V4L2_FIELD_TOP;
 247                         q->last = V4L2_FIELD_TOP;
 248                 }
 249         }
 250         return field;
 251 }
 252 EXPORT_SYMBOL_GPL(videobuf_next_field);
 253
 254 /* Locking: Caller holds q->vb_lock */
 255 static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
 256                             struct videobuf_buffer *vb, enum v4l2_buf_type type)
 257 {
 258         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
 259         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 260
 261         b->index    = vb->i;
 262         b->type     = type;
 263
 264         b->memory   = vb->memory;
 265         switch (b->memory) {
 266         case V4L2_MEMORY_MMAP:
 267                 b->m.offset  = vb->boff;
 268                 b->length    = vb->bsize;
 269                 break;
 270         case V4L2_MEMORY_USERPTR:
 271                 b->m.userptr = vb->baddr;
 272                 b->length    = vb->bsize;
 273                 break;
 274         case V4L2_MEMORY_OVERLAY:
 275                 b->m.offset  = vb->boff;
 276                 break;
 277         }
 278
 279         b->flags    = 0;
 280         if (vb->map)
 281                 b->flags |= V4L2_BUF_FLAG_MAPPED;
 282
 283         switch (vb->state) {
 284         case VIDEOBUF_PREPARED:
 285         case VIDEOBUF_QUEUED:
 286         case VIDEOBUF_ACTIVE:
 287                 b->flags |= V4L2_BUF_FLAG_QUEUED;
 288                 break;
 289         case VIDEOBUF_DONE:
 290         case VIDEOBUF_ERROR:
 291                 b->flags |= V4L2_BUF_FLAG_DONE;
 292                 break;
 293         case VIDEOBUF_NEEDS_INIT:
 294         case VIDEOBUF_IDLE:
 295                 /* nothing */
 296                 break;
 297         }
 298
 299         if (vb->input != UNSET) {
 300                 b->flags |= V4L2_BUF_FLAG_INPUT;
 301                 b->input  = vb->input;
 302         }
 303
 304         b->field     = vb->field;
 305         b->timestamp = vb->ts;
 306         b->bytesused = vb->size;
 307         b->sequence  = vb->field_count >> 1;
 308 }
 309
 310 /* Locking: Caller holds q->vb_lock */
 311 static int __videobuf_mmap_free(struct videobuf_queue *q)
 312 {
 313         int i;
 314         int rc;
 315
 316         if (!q)
 317                 return 0;
 318
 319         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 320
 321         rc = CALL(q, mmap_free, q);
 322
 323         q->is_mmapped = 0;
 324
 325         if (rc < 0)
 326                 return rc;
 327
 328         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 329                 if (NULL == q->bufs[i])
 330                         continue;
 331                 q->ops->buf_release(q, q->bufs[i]);
 332                 kfree(q->bufs[i]);
 333                 q->bufs[i] = NULL;
 334         }
 335
 336         return rc;
 337 }
 338
 339 int videobuf_mmap_free(struct videobuf_queue *q)
 340 {
 341         int ret;
 342         mutex_lock(&q->vb_lock);
 343         ret = __videobuf_mmap_free(q);
 344         mutex_unlock(&q->vb_lock);
 345         return ret;
 346 }
 347 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
 348
 349 /* Locking: Caller holds q->vb_lock */
 350 int __videobuf_mmap_setup(struct videobuf_queue *q,
 351                         unsigned int bcount, unsigned int bsize,
 352                         enum v4l2_memory memory)
 353 {
 354         unsigned int i;
 355         int err;
 356
 357         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 358
 359         err = __videobuf_mmap_free(q);
 360         if (0 != err)
 361                 return err;
 362
 363         /* Allocate and initialize buffers */
 364         for (i = 0; i < bcount; i++) {
 365                 q->bufs[i] = videobuf_alloc(q);
 366
 367                 if (NULL == q->bufs[i])
 368                         break;
 369
 370                 q->bufs[i]->i      = i;
 371                 q->bufs[i]->input  = UNSET;
 372                 q->bufs[i]->memory = memory;
 373                 q->bufs[i]->bsize  = bsize;
 374                 switch (memory) {
 375                 case V4L2_MEMORY_MMAP:
 376                         q->bufs[i]->boff = PAGE_ALIGN(bsize) * i;
 377                         break;
 378                 case V4L2_MEMORY_USERPTR:
 379                 case V4L2_MEMORY_OVERLAY:
 380                         /* nothing */
 381                         break;
 382                 }
 383         }
 384
 385         if (!i)
 386                 return -ENOMEM;
 387
 388         dprintk(1, "mmap setup: %d buffers, %d bytes each\n", i, bsize);
 389
 390         return i;
 391 }
 392 EXPORT_SYMBOL_GPL(__videobuf_mmap_setup);
 393
 394 int videobuf_mmap_setup(struct videobuf_queue *q,
 395                         unsigned int bcount, unsigned int bsize,
 396                         enum v4l2_memory memory)
 397 {
 398         int ret;
 399         mutex_lock(&q->vb_lock);
 400         ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
 401         mutex_unlock(&q->vb_lock);
 402         return ret;
 403 }
 404 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
 405
 406 int videobuf_reqbufs(struct videobuf_queue *q,
 407                  struct v4l2_requestbuffers *req)
 408 {
 409         unsigned int size, count;
 410         int retval;
 411
 412         if (req->count < 1) {
 413                 dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
 414                 return -EINVAL;
 415         }
 416
 417         if (req->memory != V4L2_MEMORY_MMAP     &&
 418             req->memory != V4L2_MEMORY_USERPTR  &&
 419             req->memory != V4L2_MEMORY_OVERLAY) {
 420                 dprintk(1, "reqbufs: memory type invalid\n");
 421                 return -EINVAL;
 422         }
 423
 424         mutex_lock(&q->vb_lock);
 425         if (req->type != q->type) {
 426                 dprintk(1, "reqbufs: queue type invalid\n");
 427                 retval = -EINVAL;
 428                 goto done;
 429         }
 430
 431         if (q->streaming) {
 432                 dprintk(1, "reqbufs: streaming already exists\n");
 433                 retval = -EBUSY;
 434                 goto done;
 435         }
 436         if (!list_empty(&q->stream)) {
 437                 dprintk(1, "reqbufs: stream running\n");
 438                 retval = -EBUSY;
 439                 goto done;
 440         }
 441
 442         count = req->count;
 443         if (count > VIDEO_MAX_FRAME)
 444                 count = VIDEO_MAX_FRAME;
 445         size = 0;
 446         q->ops->buf_setup(q, &count, &size);
 447         dprintk(1, "reqbufs: bufs=%d, size=0x%x [%u pages total]\n",
 448                 count, size,
 449                 (unsigned int)((count * PAGE_ALIGN(size)) >> PAGE_SHIFT));
 450
 451         retval = __videobuf_mmap_setup(q, count, size, req->memory);
 452         if (retval < 0) {
 453                 dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
 454                 goto done;
 455         }
 456
 457         req->count = retval;
 458         retval = 0;
 459
 460  done:
 461         mutex_unlock(&q->vb_lock);
 462         return retval;
 463 }
 464 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
 465
 466 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 467 {
 468         int ret = -EINVAL;
 469
 470         mutex_lock(&q->vb_lock);
 471         if (unlikely(b->type != q->type)) {
 472                 dprintk(1, "querybuf: Wrong type.\n");
 473                 goto done;
 474         }
 475         if (unlikely(b->index >= VIDEO_MAX_FRAME)) {
 476                 dprintk(1, "querybuf: index out of range.\n");
 477                 goto done;
 478         }
 479         if (unlikely(NULL == q->bufs[b->index])) {
 480                 dprintk(1, "querybuf: buffer is null.\n");
 481                 goto done;
 482         }
 483
 484         videobuf_status(q, b, q->bufs[b->index], q->type);
 485
 486         ret = 0;
 487 done:
 488         mutex_unlock(&q->vb_lock);
 489         return ret;
 490 }
 491 EXPORT_SYMBOL_GPL(videobuf_querybuf);
 492
 493 int videobuf_qbuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 494 {
 495         struct videobuf_buffer *buf;
 496         enum v4l2_field field;
 497         unsigned long flags = 0;
 498         int retval;
 499
 500         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 501
 502         if (b->memory == V4L2_MEMORY_MMAP)
 503                 down_read(&current->mm->mmap_sem);
 504
 505         mutex_lock(&q->vb_lock);
 506         retval = -EBUSY;
 507         if (q->reading) {
 508                 dprintk(1, "qbuf: Reading running...\n");
 509                 goto done;
 510         }
 511         retval = -EINVAL;
 512         if (b->type != q->type) {
 513                 dprintk(1, "qbuf: Wrong type.\n");
 514                 goto done;
 515         }
 516         if (b->index >= VIDEO_MAX_FRAME) {
 517                 dprintk(1, "qbuf: index out of range.\n");
 518                 goto done;
 519         }
 520         buf = q->bufs[b->index];
 521         if (NULL == buf) {
 522                 dprintk(1, "qbuf: buffer is null.\n");
 523                 goto done;
 524         }
 525         MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
 526         if (buf->memory != b->memory) {
 527                 dprintk(1, "qbuf: memory type is wrong.\n");
 528                 goto done;
 529         }
 530         if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
 531                 dprintk(1, "qbuf: buffer is already queued or active.\n");
 532                 goto done;
 533         }
 534
 535         if (b->flags & V4L2_BUF_FLAG_INPUT) {
 536                 if (b->input >= q->inputs) {
 537                         dprintk(1, "qbuf: wrong input.\n");
 538                         goto done;
 539                 }
 540                 buf->input = b->input;
 541         } else {
 542                 buf->input = UNSET;
 543         }
 544
 545         switch (b->memory) {
 546         case V4L2_MEMORY_MMAP:
 547                 if (0 == buf->baddr) {
 548                         dprintk(1, "qbuf: mmap requested "
 549                                    "but buffer addr is zero!\n");
 550                         goto done;
 551                 }
 552                 break;
 553         case V4L2_MEMORY_USERPTR:
 554                 if (b->length < buf->bsize) {
 555                         dprintk(1, "qbuf: buffer length is not enough\n");
 556                         goto done;
 557                 }
 558                 if (VIDEOBUF_NEEDS_INIT != buf->state &&
 559                     buf->baddr != b->m.userptr)
 560                         q->ops->buf_release(q, buf);
 561                 buf->baddr = b->m.userptr;
 562                 break;
 563         case V4L2_MEMORY_OVERLAY:
 564                 buf->boff = b->m.offset;
 565                 break;
 566         default:
 567                 dprintk(1, "qbuf: wrong memory type\n");
 568                 goto done;
 569         }
 570
 571         dprintk(1, "qbuf: requesting next field\n");
 572         field = videobuf_next_field(q);
 573         retval = q->ops->buf_prepare(q, buf, field);
 574         if (0 != retval) {
 575                 dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
 576                 goto done;
 577         }
 578
 579         list_add_tail(&buf->stream, &q->stream);
 580         if (q->streaming) {
 581                 spin_lock_irqsave(q->irqlock, flags);
 582                 q->ops->buf_queue(q, buf);
 583                 spin_unlock_irqrestore(q->irqlock, flags);
 584         }
 585         dprintk(1, "qbuf: succeeded\n");
 586         retval = 0;
 587         wake_up_interruptible_sync(&q->wait);
 588
 589 done:
 590         mutex_unlock(&q->vb_lock);
 591
 592         if (b->memory == V4L2_MEMORY_MMAP)
 593                 up_read(&current->mm->mmap_sem);
 594
 595         return retval;
 596 }
 597 EXPORT_SYMBOL_GPL(videobuf_qbuf);
 598
 599 /* Locking: Caller holds q->vb_lock */
 600 static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
 601 {
 602         int retval;
 603
 604 checks:
 605         if (!q->streaming) {
 606                 dprintk(1, "next_buffer: Not streaming\n");
 607                 retval = -EINVAL;
 608                 goto done;
 609         }
 610
 611         if (list_empty(&q->stream)) {
 612                 if (noblock) {
 613                         retval = -EAGAIN;
 614                         dprintk(2, "next_buffer: no buffers to dequeue\n");
 615                         goto done;
 616                 } else {
 617                         dprintk(2, "next_buffer: waiting on buffer\n");
 618
 619                         /* Drop lock to avoid deadlock with qbuf */
 620                         mutex_unlock(&q->vb_lock);
 621
 622                         /* Checking list_empty and streaming is safe without
 623                          * locks because we goto checks to validate while
 624                          * holding locks before proceeding */
 625                         retval = wait_event_interruptible(q->wait,
 626                                 !list_empty(&q->stream) || !q->streaming);
 627                         mutex_lock(&q->vb_lock);
 628
 629                         if (retval)
 630                                 goto done;
 631
 632                         goto checks;
 633                 }
 634         }
 635
 636         retval = 0;
 637
 638 done:
 639         return retval;
 640 }
 641
 642 /* Locking: Caller holds q->vb_lock */
 643 static int stream_next_buffer(struct videobuf_queue *q,
 644                         struct videobuf_buffer **vb, int nonblocking)
 645 {
 646         int retval;
 647         struct videobuf_buffer *buf = NULL;
 648
 649         retval = stream_next_buffer_check_queue(q, nonblocking);
 650         if (retval)
 651                 goto done;
 652
 653         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 654         retval = videobuf_waiton(buf, nonblocking, 1);
 655         if (retval < 0)
 656                 goto done;
 657
 658         *vb = buf;
 659 done:
 660         return retval;
 661 }
 662
 663 int videobuf_dqbuf(struct videobuf_queue *q,
 664                    struct v4l2_buffer *b, int nonblocking)
 665 {
 666         struct videobuf_buffer *buf = NULL;
 667         int retval;
 668
 669         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 670
 671         mutex_lock(&q->vb_lock);
 672
 673         retval = stream_next_buffer(q, &buf, nonblocking);
 674         if (retval < 0) {
 675                 dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
 676                 goto done;
 677         }
 678
 679         switch (buf->state) {
 680         case VIDEOBUF_ERROR:
 681                 dprintk(1, "dqbuf: state is error\n");
 682                 retval = -EIO;
 683                 CALL(q, sync, q, buf);
 684                 buf->state = VIDEOBUF_IDLE;
 685                 break;
 686         case VIDEOBUF_DONE:
 687                 dprintk(1, "dqbuf: state is done\n");
 688                 CALL(q, sync, q, buf);
 689                 buf->state = VIDEOBUF_IDLE;
 690                 break;
 691         default:
 692                 dprintk(1, "dqbuf: state invalid\n");
 693                 retval = -EINVAL;
 694                 goto done;
 695         }
 696         list_del(&buf->stream);
 697         memset(b, 0, sizeof(*b));
 698         videobuf_status(q, b, buf, q->type);
 699 done:
 700         mutex_unlock(&q->vb_lock);
 701         return retval;
 702 }
 703 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
 704
 705 int videobuf_streamon(struct videobuf_queue *q)
 706 {
 707         struct videobuf_buffer *buf;
 708         unsigned long flags = 0;
 709         int retval;
 710
 711         mutex_lock(&q->vb_lock);
 712         retval = -EBUSY;
 713         if (q->reading)
 714                 goto done;
 715         retval = 0;
 716         if (q->streaming)
 717                 goto done;
 718         q->streaming = 1;
 719         spin_lock_irqsave(q->irqlock, flags);
 720         list_for_each_entry(buf, &q->stream, stream)
 721                 if (buf->state == VIDEOBUF_PREPARED)
 722                         q->ops->buf_queue(q, buf);
 723         spin_unlock_irqrestore(q->irqlock, flags);
 724
 725         wake_up_interruptible_sync(&q->wait);
 726 done:
 727         mutex_unlock(&q->vb_lock);
 728         return retval;
 729 }
 730 EXPORT_SYMBOL_GPL(videobuf_streamon);
 731
 732 /* Locking: Caller holds q->vb_lock */
 733 static int __videobuf_streamoff(struct videobuf_queue *q)
 734 {
 735         if (!q->streaming)
 736                 return -EINVAL;
 737
 738         videobuf_queue_cancel(q);
 739
 740         return 0;
 741 }
 742
 743 int videobuf_streamoff(struct videobuf_queue *q)
 744 {
 745         int retval;
 746
 747         mutex_lock(&q->vb_lock);
 748         retval = __videobuf_streamoff(q);
 749         mutex_unlock(&q->vb_lock);
 750
 751         return retval;
 752 }
 753 EXPORT_SYMBOL_GPL(videobuf_streamoff);
 754
 755 /* Locking: Caller holds q->vb_lock */
 756 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
 757                                       char __user *data,
 758                                       size_t count, loff_t *ppos)
 759 {
 760         enum v4l2_field field;
 761         unsigned long flags = 0;
 762         int retval;
 763
 764         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 765
 766         /* setup stuff */
 767         q->read_buf = videobuf_alloc(q);
 768         if (NULL == q->read_buf)
 769                 return -ENOMEM;
 770
 771         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 772         q->read_buf->baddr  = (unsigned long)data;
 773         q->read_buf->bsize  = count;
 774
 775         field = videobuf_next_field(q);
 776         retval = q->ops->buf_prepare(q, q->read_buf, field);
 777         if (0 != retval)
 778                 goto done;
 779
 780         /* start capture & wait */
 781         spin_lock_irqsave(q->irqlock, flags);
 782         q->ops->buf_queue(q, q->read_buf);
 783         spin_unlock_irqrestore(q->irqlock, flags);
 784         retval = videobuf_waiton(q->read_buf, 0, 0);
 785         if (0 == retval) {
 786                 CALL(q, sync, q, q->read_buf);
 787                 if (VIDEOBUF_ERROR == q->read_buf->state)
 788                         retval = -EIO;
 789                 else
 790                         retval = q->read_buf->size;
 791         }
 792
 793 done:
 794         /* cleanup */
 795         q->ops->buf_release(q, q->read_buf);
 796         kfree(q->read_buf);
 797         q->read_buf = NULL;
 798         return retval;
 799 }
 800
 801 ssize_t videobuf_read_one(struct videobuf_queue *q,
 802                           char __user *data, size_t count, loff_t *ppos,
 803                           int nonblocking)
 804 {
 805         enum v4l2_field field;
 806         unsigned long flags = 0;
 807         unsigned size = 0, nbufs = 1;
 808         int retval;
 809
 810         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 811
 812         mutex_lock(&q->vb_lock);
 813
 814         q->ops->buf_setup(q, &nbufs, &size);
 815
 816         if (NULL == q->read_buf  &&
 817             count >= size        &&
 818             !nonblocking) {
 819                 retval = videobuf_read_zerocopy(q, data, count, ppos);
 820                 if (retval >= 0  ||  retval == -EIO)
 821                         /* ok, all done */
 822                         goto done;
 823                 /* fallback to kernel bounce buffer on failures */
 824         }
 825
 826         if (NULL == q->read_buf) {
 827                 /* need to capture a new frame */
 828                 retval = -ENOMEM;
 829                 q->read_buf = videobuf_alloc(q);
 830
 831                 dprintk(1, "video alloc=0x%p\n", q->read_buf);
 832                 if (NULL == q->read_buf)
 833                         goto done;
 834                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 835                 q->read_buf->bsize = count; /* preferred size */
 836                 field = videobuf_next_field(q);
 837                 retval = q->ops->buf_prepare(q, q->read_buf, field);
 838
 839                 if (0 != retval) {
 840                         kfree(q->read_buf);
 841                         q->read_buf = NULL;
 842                         goto done;
 843                 }
 844
 845                 spin_lock_irqsave(q->irqlock, flags);
 846                 q->ops->buf_queue(q, q->read_buf);
 847                 spin_unlock_irqrestore(q->irqlock, flags);
 848
 849                 q->read_off = 0;
 850         }
 851
 852         /* wait until capture is done */
 853         retval = videobuf_waiton(q->read_buf, nonblocking, 1);
 854         if (0 != retval)
 855                 goto done;
 856
 857         CALL(q, sync, q, q->read_buf);
 858
 859         if (VIDEOBUF_ERROR == q->read_buf->state) {
 860                 /* catch I/O errors */
 861                 q->ops->buf_release(q, q->read_buf);
 862                 kfree(q->read_buf);
 863                 q->read_buf = NULL;
 864                 retval = -EIO;
 865                 goto done;
 866         }
 867
 868         /* Copy to userspace */
 869         retval = CALL(q, video_copy_to_user, q, data, count, nonblocking);
 870         if (retval < 0)
 871                 goto done;
 872
 873         q->read_off += retval;
 874         if (q->read_off == q->read_buf->size) {
 875                 /* all data copied, cleanup */
 876                 q->ops->buf_release(q, q->read_buf);
 877                 kfree(q->read_buf);
 878                 q->read_buf = NULL;
 879         }
 880
 881 done:
 882         mutex_unlock(&q->vb_lock);
 883         return retval;
 884 }
 885 EXPORT_SYMBOL_GPL(videobuf_read_one);
 886
 887 /* Locking: Caller holds q->vb_lock */
 888 static int __videobuf_read_start(struct videobuf_queue *q)
 889 {
 890         enum v4l2_field field;
 891         unsigned long flags = 0;
 892         unsigned int count = 0, size = 0;
 893         int err, i;
 894
 895         q->ops->buf_setup(q, &count, &size);
 896         if (count < 2)
 897                 count = 2;
 898         if (count > VIDEO_MAX_FRAME)
 899                 count = VIDEO_MAX_FRAME;
 900         size = PAGE_ALIGN(size);
 901
 902         err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
 903         if (err < 0)
 904                 return err;
 905
 906         count = err;
 907
 908         for (i = 0; i < count; i++) {
 909                 field = videobuf_next_field(q);
 910                 err = q->ops->buf_prepare(q, q->bufs[i], field);
 911                 if (err)
 912                         return err;
 913                 list_add_tail(&q->bufs[i]->stream, &q->stream);
 914         }
 915         spin_lock_irqsave(q->irqlock, flags);
 916         for (i = 0; i < count; i++)
 917                 q->ops->buf_queue(q, q->bufs[i]);
 918         spin_unlock_irqrestore(q->irqlock, flags);
 919         q->reading = 1;
 920         return 0;
 921 }
 922
 923 static void __videobuf_read_stop(struct videobuf_queue *q)
 924 {
 925         int i;
 926
 927         videobuf_queue_cancel(q);
 928         __videobuf_mmap_free(q);
 929         INIT_LIST_HEAD(&q->stream);
 930         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 931                 if (NULL == q->bufs[i])
 932                         continue;
 933                 kfree(q->bufs[i]);
 934                 q->bufs[i] = NULL;
 935         }
 936         q->read_buf = NULL;
 937 }
 938
 939 int videobuf_read_start(struct videobuf_queue *q)
 940 {
 941         int rc;
 942
 943         mutex_lock(&q->vb_lock);
 944         rc = __videobuf_read_start(q);
 945         mutex_unlock(&q->vb_lock);
 946
 947         return rc;
 948 }
 949 EXPORT_SYMBOL_GPL(videobuf_read_start);
 950
 951 void videobuf_read_stop(struct videobuf_queue *q)
 952 {
 953         mutex_lock(&q->vb_lock);
 954         __videobuf_read_stop(q);
 955         mutex_unlock(&q->vb_lock);
 956 }
 957 EXPORT_SYMBOL_GPL(videobuf_read_stop);
 958
 959 void videobuf_stop(struct videobuf_queue *q)
 960 {
 961         mutex_lock(&q->vb_lock);
 962
 963         if (q->streaming)
 964                 __videobuf_streamoff(q);
 965
 966         if (q->reading)
 967                 __videobuf_read_stop(q);
 968
 969         mutex_unlock(&q->vb_lock);
 970 }
 971 EXPORT_SYMBOL_GPL(videobuf_stop);
 972
 973 ssize_t videobuf_read_stream(struct videobuf_queue *q,
 974                              char __user *data, size_t count, loff_t *ppos,
 975                              int vbihack, int nonblocking)
 976 {
 977         int rc, retval;
 978         unsigned long flags = 0;
 979
 980         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 981
 982         dprintk(2, "%s\n", __func__);
 983         mutex_lock(&q->vb_lock);
 984         retval = -EBUSY;
 985         if (q->streaming)
 986                 goto done;
 987         if (!q->reading) {
 988                 retval = __videobuf_read_start(q);
 989                 if (retval < 0)
 990                         goto done;
 991         }
 992
 993         retval = 0;
 994         while (count > 0) {
 995                 /* get / wait for data */
 996                 if (NULL == q->read_buf) {
 997                         q->read_buf = list_entry(q->stream.next,
 998                                                  struct videobuf_buffer,
 999                                                  stream);
1000                         list_del(&q->read_buf->stream);
1001                         q->read_off = 0;
1002                 }
1003                 rc = videobuf_waiton(q->read_buf, nonblocking, 1);
1004                 if (rc < 0) {
1005                         if (0 == retval)
1006                                 retval = rc;
1007                         break;
1008                 }
1009
1010                 if (q->read_buf->state == VIDEOBUF_DONE) {
1011                         rc = CALL(q, copy_stream, q, data + retval, count,
1012                                         retval, vbihack, nonblocking);
1013                         if (rc < 0) {
1014                                 retval = rc;
1015                                 break;
1016                         }
1017                         retval      += rc;
1018                         count       -= rc;
1019                         q->read_off += rc;
1020                 } else {
1021                         /* some error */
1022                         q->read_off = q->read_buf->size;
1023                         if (0 == retval)
1024                                 retval = -EIO;
1025                 }
1026
1027                 /* requeue buffer when done with copying */
1028                 if (q->read_off == q->read_buf->size) {
1029                         list_add_tail(&q->read_buf->stream,
1030                                       &q->stream);
1031                         spin_lock_irqsave(q->irqlock, flags);
1032                         q->ops->buf_queue(q, q->read_buf);
1033                         spin_unlock_irqrestore(q->irqlock, flags);
1034                         q->read_buf = NULL;
1035                 }
1036                 if (retval < 0)
1037                         break;
1038         }
1039
1040 done:
1041         mutex_unlock(&q->vb_lock);
1042         return retval;
1043 }
1044 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1045
1046 unsigned int videobuf_poll_stream(struct file *file,
1047                                   struct videobuf_queue *q,
1048                                   poll_table *wait)
1049 {
1050         struct videobuf_buffer *buf = NULL;
1051         unsigned int rc = 0;
1052
1053         mutex_lock(&q->vb_lock);
1054         if (q->streaming) {
1055                 if (!list_empty(&q->stream))
1056                         buf = list_entry(q->stream.next,
1057                                          struct videobuf_buffer, stream);
1058         } else {
1059                 if (!q->reading)
1060                         __videobuf_read_start(q);
1061                 if (!q->reading) {
1062                         rc = POLLERR;
1063                 } else if (NULL == q->read_buf) {
1064                         q->read_buf = list_entry(q->stream.next,
1065                                                  struct videobuf_buffer,
1066                                                  stream);
1067                         list_del(&q->read_buf->stream);
1068                         q->read_off = 0;
1069                 }
1070                 buf = q->read_buf;
1071         }
1072         if (!buf)
1073                 rc = POLLERR;
1074
1075         if (0 == rc) {
1076                 poll_wait(file, &buf->done, wait);
1077                 if (buf->state == VIDEOBUF_DONE ||
1078                     buf->state == VIDEOBUF_ERROR)
1079                         rc = POLLIN|POLLRDNORM;
1080         }
1081         mutex_unlock(&q->vb_lock);
1082         return rc;
1083 }
1084 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1085
1086 int videobuf_mmap_mapper(struct videobuf_queue *q, struct vm_area_struct *vma)
1087 {
1088         int retval;
1089
1090         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1091
1092         mutex_lock(&q->vb_lock);
1093         retval = CALL(q, mmap_mapper, q, vma);
1094         q->is_mmapped = 1;
1095         mutex_unlock(&q->vb_lock);
1096
1097         return retval;
1098 }
1099 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
1100
1101 #ifdef CONFIG_VIDEO_V4L1_COMPAT
1102 int videobuf_cgmbuf(struct videobuf_queue *q,
1103                     struct video_mbuf *mbuf, int count)
1104 {
1105         struct v4l2_requestbuffers req;
1106         int rc, i;
1107
1108         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1109
1110         memset(&req, 0, sizeof(req));
1111         req.type   = q->type;
1112         req.count  = count;
1113         req.memory = V4L2_MEMORY_MMAP;
1114         rc = videobuf_reqbufs(q, &req);
1115         if (rc < 0)
1116                 return rc;
1117
1118         mbuf->frames = req.count;
1119         mbuf->size   = 0;
1120         for (i = 0; i < mbuf->frames; i++) {
1121                 mbuf->offsets[i]  = q->bufs[i]->boff;
1122                 mbuf->size       += PAGE_ALIGN(q->bufs[i]->bsize);
1123         }
1124
1125         return 0;
1126 }
1127 EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
1128 #endif
1129