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/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) do {                                       \
  26         if (unlikely((is) != (should))) {                                  \
  27         printk(KERN_ERR "magic mismatch: %x (expected %x)\n", is, should); \
  28         BUG(); } } while (0)
  29
  30 static int debug;
  31 module_param(debug, int, 0644);
  32
  33 MODULE_DESCRIPTION("helper module to manage video4linux buffers");
  34 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
  35 MODULE_LICENSE("GPL");
  36
  37 #define dprintk(level, fmt, arg...) do {                        \
  38         if (debug >= level)                                     \
  39         printk(KERN_DEBUG "vbuf: " fmt , ## arg); } while (0)
  40
  41 /* --------------------------------------------------------------------- */
  42
  43 #define CALL(q, f, arg...)                                              \
  44         ((q->int_ops->f) ? q->int_ops->f(arg) : 0)
  45
  46 void *videobuf_alloc(struct videobuf_queue *q)
  47 {
  48         struct videobuf_buffer *vb;
  49
  50         BUG_ON(q->msize < sizeof(*vb));
  51
  52         if (!q->int_ops || !q->int_ops->alloc) {
  53                 printk(KERN_ERR "No specific ops defined!\n");
  54                 BUG();
  55         }
  56
  57         vb = q->int_ops->alloc(q->msize);
  58
  59         if (NULL != vb) {
  60                 init_waitqueue_head(&vb->done);
  61                 vb->magic     = MAGIC_BUFFER;
  62         }
  63
  64         return vb;
  65 }
  66
  67 #define WAITON_CONDITION (vb->state != VIDEOBUF_ACTIVE &&\
  68                                 vb->state != VIDEOBUF_QUEUED)
  69 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
  70 {
  71         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
  72
  73         if (non_blocking) {
  74                 if (WAITON_CONDITION)
  75                         return 0;
  76                 else
  77                         return -EAGAIN;
  78         }
  79
  80         if (intr)
  81                 return wait_event_interruptible(vb->done, WAITON_CONDITION);
  82         else
  83                 wait_event(vb->done, WAITON_CONDITION);
  84
  85         return 0;
  86 }
  87
  88 int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
  89                     struct v4l2_framebuffer *fbuf)
  90 {
  91         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
  92         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
  93
  94         return CALL(q, iolock, q, vb, fbuf);
  95 }
  96
  97 void *videobuf_queue_to_vmalloc (struct videobuf_queue *q,
  98                            struct videobuf_buffer *buf)
  99 {
 100         if (q->int_ops->vmalloc)
 101                 return q->int_ops->vmalloc(buf);
 102         else
 103                 return NULL;
 104 }
 105 EXPORT_SYMBOL_GPL(videobuf_queue_to_vmalloc);
 106
 107 /* --------------------------------------------------------------------- */
 108
 109
 110 void videobuf_queue_core_init(struct videobuf_queue *q,
 111                          struct videobuf_queue_ops *ops,
 112                          struct device *dev,
 113                          spinlock_t *irqlock,
 114                          enum v4l2_buf_type type,
 115                          enum v4l2_field field,
 116                          unsigned int msize,
 117                          void *priv,
 118                          struct videobuf_qtype_ops *int_ops)
 119 {
 120         memset(q, 0, sizeof(*q));
 121         q->irqlock   = irqlock;
 122         q->dev       = dev;
 123         q->type      = type;
 124         q->field     = field;
 125         q->msize     = msize;
 126         q->ops       = ops;
 127         q->priv_data = priv;
 128         q->int_ops   = int_ops;
 129
 130         /* All buffer operations are mandatory */
 131         BUG_ON(!q->ops->buf_setup);
 132         BUG_ON(!q->ops->buf_prepare);
 133         BUG_ON(!q->ops->buf_queue);
 134         BUG_ON(!q->ops->buf_release);
 135
 136         /* Lock is mandatory for queue_cancel to work */
 137         BUG_ON(!irqlock);
 138
 139         /* Having implementations for abstract methods are mandatory */
 140         BUG_ON(!q->int_ops);
 141
 142         mutex_init(&q->vb_lock);
 143         init_waitqueue_head(&q->wait);
 144         INIT_LIST_HEAD(&q->stream);
 145 }
 146
 147 /* Locking: Only usage in bttv unsafe find way to remove */
 148 int videobuf_queue_is_busy(struct videobuf_queue *q)
 149 {
 150         int i;
 151
 152         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 153
 154         if (q->streaming) {
 155                 dprintk(1, "busy: streaming active\n");
 156                 return 1;
 157         }
 158         if (q->reading) {
 159                 dprintk(1, "busy: pending read #1\n");
 160                 return 1;
 161         }
 162         if (q->read_buf) {
 163                 dprintk(1, "busy: pending read #2\n");
 164                 return 1;
 165         }
 166         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 167                 if (NULL == q->bufs[i])
 168                         continue;
 169                 if (q->bufs[i]->map) {
 170                         dprintk(1, "busy: buffer #%d mapped\n", i);
 171                         return 1;
 172                 }
 173                 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
 174                         dprintk(1, "busy: buffer #%d queued\n", i);
 175                         return 1;
 176                 }
 177                 if (q->bufs[i]->state == VIDEOBUF_ACTIVE) {
 178                         dprintk(1, "busy: buffer #%d avtive\n", i);
 179                         return 1;
 180                 }
 181         }
 182         return 0;
 183 }
 184
 185 /* Locking: Caller holds q->vb_lock */
 186 void videobuf_queue_cancel(struct videobuf_queue *q)
 187 {
 188         unsigned long flags = 0;
 189         int i;
 190
 191         q->streaming = 0;
 192         q->reading  = 0;
 193         wake_up_interruptible_sync(&q->wait);
 194
 195         /* remove queued buffers from list */
 196         spin_lock_irqsave(q->irqlock, flags);
 197         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 198                 if (NULL == q->bufs[i])
 199                         continue;
 200                 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
 201                         list_del(&q->bufs[i]->queue);
 202                         q->bufs[i]->state = VIDEOBUF_ERROR;
 203                         wake_up_all(&q->bufs[i]->done);
 204                 }
 205         }
 206         spin_unlock_irqrestore(q->irqlock, flags);
 207
 208         /* free all buffers + clear queue */
 209         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 210                 if (NULL == q->bufs[i])
 211                         continue;
 212                 q->ops->buf_release(q, q->bufs[i]);
 213         }
 214         INIT_LIST_HEAD(&q->stream);
 215 }
 216
 217 /* --------------------------------------------------------------------- */
 218
 219 /* Locking: Caller holds q->vb_lock */
 220 enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
 221 {
 222         enum v4l2_field field = q->field;
 223
 224         BUG_ON(V4L2_FIELD_ANY == field);
 225
 226         if (V4L2_FIELD_ALTERNATE == field) {
 227                 if (V4L2_FIELD_TOP == q->last) {
 228                         field   = V4L2_FIELD_BOTTOM;
 229                         q->last = V4L2_FIELD_BOTTOM;
 230                 } else {
 231                         field   = V4L2_FIELD_TOP;
 232                         q->last = V4L2_FIELD_TOP;
 233                 }
 234         }
 235         return field;
 236 }
 237
 238 /* Locking: Caller holds q->vb_lock */
 239 static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
 240                             struct videobuf_buffer *vb, enum v4l2_buf_type type)
 241 {
 242         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
 243         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 244
 245         b->index    = vb->i;
 246         b->type     = type;
 247
 248         b->memory   = vb->memory;
 249         switch (b->memory) {
 250         case V4L2_MEMORY_MMAP:
 251                 b->m.offset  = vb->boff;
 252                 b->length    = vb->bsize;
 253                 break;
 254         case V4L2_MEMORY_USERPTR:
 255                 b->m.userptr = vb->baddr;
 256                 b->length    = vb->bsize;
 257                 break;
 258         case V4L2_MEMORY_OVERLAY:
 259                 b->m.offset  = vb->boff;
 260                 break;
 261         }
 262
 263         b->flags    = 0;
 264         if (vb->map)
 265                 b->flags |= V4L2_BUF_FLAG_MAPPED;
 266
 267         switch (vb->state) {
 268         case VIDEOBUF_PREPARED:
 269         case VIDEOBUF_QUEUED:
 270         case VIDEOBUF_ACTIVE:
 271                 b->flags |= V4L2_BUF_FLAG_QUEUED;
 272                 break;
 273         case VIDEOBUF_DONE:
 274         case VIDEOBUF_ERROR:
 275                 b->flags |= V4L2_BUF_FLAG_DONE;
 276                 break;
 277         case VIDEOBUF_NEEDS_INIT:
 278         case VIDEOBUF_IDLE:
 279                 /* nothing */
 280                 break;
 281         }
 282
 283         if (vb->input != UNSET) {
 284                 b->flags |= V4L2_BUF_FLAG_INPUT;
 285                 b->input  = vb->input;
 286         }
 287
 288         b->field     = vb->field;
 289         b->timestamp = vb->ts;
 290         b->bytesused = vb->size;
 291         b->sequence  = vb->field_count >> 1;
 292 }
 293
 294 /* Locking: Caller holds q->vb_lock */
 295 static int __videobuf_mmap_free(struct videobuf_queue *q)
 296 {
 297         int i;
 298         int rc;
 299
 300         if (!q)
 301                 return 0;
 302
 303         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 304
 305
 306         rc  = CALL(q, mmap_free, q);
 307
 308         q->is_mmapped = 0;
 309
 310         if (rc < 0)
 311                 return rc;
 312
 313         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 314                 if (NULL == q->bufs[i])
 315                         continue;
 316                 q->ops->buf_release(q, q->bufs[i]);
 317                 kfree(q->bufs[i]);
 318                 q->bufs[i] = NULL;
 319         }
 320
 321         return rc;
 322 }
 323
 324 int videobuf_mmap_free(struct videobuf_queue *q)
 325 {
 326         int ret;
 327         mutex_lock(&q->vb_lock);
 328         ret = __videobuf_mmap_free(q);
 329         mutex_unlock(&q->vb_lock);
 330         return ret;
 331 }
 332
 333 /* Locking: Caller holds q->vb_lock */
 334 int __videobuf_mmap_setup(struct videobuf_queue *q,
 335                         unsigned int bcount, unsigned int bsize,
 336                         enum v4l2_memory memory)
 337 {
 338         unsigned int i;
 339         int err;
 340
 341         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 342
 343         err = __videobuf_mmap_free(q);
 344         if (0 != err)
 345                 return err;
 346
 347         /* Allocate and initialize buffers */
 348         for (i = 0; i < bcount; i++) {
 349                 q->bufs[i] = videobuf_alloc(q);
 350
 351                 if (q->bufs[i] == NULL)
 352                         break;
 353
 354                 q->bufs[i]->i      = i;
 355                 q->bufs[i]->input  = UNSET;
 356                 q->bufs[i]->memory = memory;
 357                 q->bufs[i]->bsize  = bsize;
 358                 switch (memory) {
 359                 case V4L2_MEMORY_MMAP:
 360                         q->bufs[i]->boff  = bsize * i;
 361                         break;
 362                 case V4L2_MEMORY_USERPTR:
 363                 case V4L2_MEMORY_OVERLAY:
 364                         /* nothing */
 365                         break;
 366                 }
 367         }
 368
 369         if (!i)
 370                 return -ENOMEM;
 371
 372         dprintk(1, "mmap setup: %d buffers, %d bytes each\n",
 373                 i, bsize);
 374
 375         return i;
 376 }
 377
 378 int videobuf_mmap_setup(struct videobuf_queue *q,
 379                         unsigned int bcount, unsigned int bsize,
 380                         enum v4l2_memory memory)
 381 {
 382         int ret;
 383         mutex_lock(&q->vb_lock);
 384         ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
 385         mutex_unlock(&q->vb_lock);
 386         return ret;
 387 }
 388
 389 int videobuf_reqbufs(struct videobuf_queue *q,
 390                  struct v4l2_requestbuffers *req)
 391 {
 392         unsigned int size, count;
 393         int retval;
 394
 395         if (req->count < 1) {
 396                 dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
 397                 return -EINVAL;
 398         }
 399
 400         if (req->memory != V4L2_MEMORY_MMAP     &&
 401             req->memory != V4L2_MEMORY_USERPTR  &&
 402             req->memory != V4L2_MEMORY_OVERLAY) {
 403                 dprintk(1, "reqbufs: memory type invalid\n");
 404                 return -EINVAL;
 405         }
 406
 407         mutex_lock(&q->vb_lock);
 408         if (req->type != q->type) {
 409                 dprintk(1, "reqbufs: queue type invalid\n");
 410                 retval = -EINVAL;
 411                 goto done;
 412         }
 413
 414         if (q->streaming) {
 415                 dprintk(1, "reqbufs: streaming already exists\n");
 416                 retval = -EBUSY;
 417                 goto done;
 418         }
 419         if (!list_empty(&q->stream)) {
 420                 dprintk(1, "reqbufs: stream running\n");
 421                 retval = -EBUSY;
 422                 goto done;
 423         }
 424
 425         count = req->count;
 426         if (count > VIDEO_MAX_FRAME)
 427                 count = VIDEO_MAX_FRAME;
 428         size = 0;
 429         q->ops->buf_setup(q, &count, &size);
 430         size = PAGE_ALIGN(size);
 431         dprintk(1, "reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
 432                 count, size, (count*size)>>PAGE_SHIFT);
 433
 434         retval = __videobuf_mmap_setup(q, count, size, req->memory);
 435         if (retval < 0) {
 436                 dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
 437                 goto done;
 438         }
 439
 440         req->count = retval;
 441
 442  done:
 443         mutex_unlock(&q->vb_lock);
 444         return retval;
 445 }
 446
 447 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 448 {
 449         int ret = -EINVAL;
 450
 451         mutex_lock(&q->vb_lock);
 452         if (unlikely(b->type != q->type)) {
 453                 dprintk(1, "querybuf: Wrong type.\n");
 454                 goto done;
 455         }
 456         if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME)) {
 457                 dprintk(1, "querybuf: index out of range.\n");
 458                 goto done;
 459         }
 460         if (unlikely(NULL == q->bufs[b->index])) {
 461                 dprintk(1, "querybuf: buffer is null.\n");
 462                 goto done;
 463         }
 464
 465         videobuf_status(q, b, q->bufs[b->index], q->type);
 466
 467         ret = 0;
 468 done:
 469         mutex_unlock(&q->vb_lock);
 470         return ret;
 471 }
 472
 473 int videobuf_qbuf(struct videobuf_queue *q,
 474               struct v4l2_buffer *b)
 475 {
 476         struct videobuf_buffer *buf;
 477         enum v4l2_field field;
 478         unsigned long flags = 0;
 479         int retval;
 480
 481         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 482
 483         if (b->memory == V4L2_MEMORY_MMAP)
 484                 down_read(&current->mm->mmap_sem);
 485
 486         mutex_lock(&q->vb_lock);
 487         retval = -EBUSY;
 488         if (q->reading) {
 489                 dprintk(1, "qbuf: Reading running...\n");
 490                 goto done;
 491         }
 492         retval = -EINVAL;
 493         if (b->type != q->type) {
 494                 dprintk(1, "qbuf: Wrong type.\n");
 495                 goto done;
 496         }
 497         if (b->index < 0 || b->index >= VIDEO_MAX_FRAME) {
 498                 dprintk(1, "qbuf: index out of range.\n");
 499                 goto done;
 500         }
 501         buf = q->bufs[b->index];
 502         if (NULL == buf) {
 503                 dprintk(1, "qbuf: buffer is null.\n");
 504                 goto done;
 505         }
 506         MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
 507         if (buf->memory != b->memory) {
 508                 dprintk(1, "qbuf: memory type is wrong.\n");
 509                 goto done;
 510         }
 511         if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
 512                 dprintk(1, "qbuf: buffer is already queued or active.\n");
 513                 goto done;
 514         }
 515
 516         if (b->flags & V4L2_BUF_FLAG_INPUT) {
 517                 if (b->input >= q->inputs) {
 518                         dprintk(1, "qbuf: wrong input.\n");
 519                         goto done;
 520                 }
 521                 buf->input = b->input;
 522         } else {
 523                 buf->input = UNSET;
 524         }
 525
 526         switch (b->memory) {
 527         case V4L2_MEMORY_MMAP:
 528                 if (0 == buf->baddr) {
 529                         dprintk(1, "qbuf: mmap requested "
 530                                    "but buffer addr is zero!\n");
 531                         goto done;
 532                 }
 533                 break;
 534         case V4L2_MEMORY_USERPTR:
 535                 if (b->length < buf->bsize) {
 536                         dprintk(1, "qbuf: buffer length is not enough\n");
 537                         goto done;
 538                 }
 539                 if (VIDEOBUF_NEEDS_INIT != buf->state &&
 540                     buf->baddr != b->m.userptr)
 541                         q->ops->buf_release(q, buf);
 542                 buf->baddr = b->m.userptr;
 543                 break;
 544         case V4L2_MEMORY_OVERLAY:
 545                 buf->boff = b->m.offset;
 546                 break;
 547         default:
 548                 dprintk(1, "qbuf: wrong memory type\n");
 549                 goto done;
 550         }
 551
 552         dprintk(1, "qbuf: requesting next field\n");
 553         field = videobuf_next_field(q);
 554         retval = q->ops->buf_prepare(q, buf, field);
 555         if (0 != retval) {
 556                 dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
 557                 goto done;
 558         }
 559
 560         list_add_tail(&buf->stream, &q->stream);
 561         if (q->streaming) {
 562                 spin_lock_irqsave(q->irqlock, flags);
 563                 q->ops->buf_queue(q, buf);
 564                 spin_unlock_irqrestore(q->irqlock, flags);
 565         }
 566         dprintk(1, "qbuf: succeded\n");
 567         retval = 0;
 568         wake_up_interruptible_sync(&q->wait);
 569
 570  done:
 571         mutex_unlock(&q->vb_lock);
 572
 573         if (b->memory == V4L2_MEMORY_MMAP)
 574                 up_read(&current->mm->mmap_sem);
 575
 576         return retval;
 577 }
 578
 579
 580 /* Locking: Caller holds q->vb_lock */
 581 static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
 582 {
 583         int retval;
 584
 585 checks:
 586         if (!q->streaming) {
 587                 dprintk(1, "next_buffer: Not streaming\n");
 588                 retval = -EINVAL;
 589                 goto done;
 590         }
 591
 592         if (list_empty(&q->stream)) {
 593                 if (noblock) {
 594                         retval = -EAGAIN;
 595                         dprintk(2, "next_buffer: no buffers to dequeue\n");
 596                         goto done;
 597                 } else {
 598                         dprintk(2, "next_buffer: waiting on buffer\n");
 599
 600                         /* Drop lock to avoid deadlock with qbuf */
 601                         mutex_unlock(&q->vb_lock);
 602
 603                         /* Checking list_empty and streaming is safe without
 604                          * locks because we goto checks to validate while
 605                          * holding locks before proceeding */
 606                         retval = wait_event_interruptible(q->wait,
 607                                 !list_empty(&q->stream) || !q->streaming);
 608                         mutex_lock(&q->vb_lock);
 609
 610                         if (retval)
 611                                 goto done;
 612
 613                         goto checks;
 614                 }
 615         }
 616
 617         retval = 0;
 618
 619 done:
 620         return retval;
 621 }
 622
 623
 624 /* Locking: Caller holds q->vb_lock */
 625 static int stream_next_buffer(struct videobuf_queue *q,
 626                         struct videobuf_buffer **vb, int nonblocking)
 627 {
 628         int retval;
 629         struct videobuf_buffer *buf = NULL;
 630
 631         retval = stream_next_buffer_check_queue(q, nonblocking);
 632         if (retval)
 633                 goto done;
 634
 635         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 636         retval = videobuf_waiton(buf, nonblocking, 1);
 637         if (retval < 0)
 638                 goto done;
 639
 640         *vb = buf;
 641 done:
 642         return retval;
 643 }
 644
 645 int videobuf_dqbuf(struct videobuf_queue *q,
 646                struct v4l2_buffer *b, int nonblocking)
 647 {
 648         struct videobuf_buffer *buf = NULL;
 649         int retval;
 650
 651         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 652
 653         mutex_lock(&q->vb_lock);
 654
 655         retval = stream_next_buffer(q, &buf, nonblocking);
 656         if (retval < 0) {
 657                 dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
 658                 goto done;
 659         }
 660
 661         switch (buf->state) {
 662         case VIDEOBUF_ERROR:
 663                 dprintk(1, "dqbuf: state is error\n");
 664                 retval = -EIO;
 665                 CALL(q, sync, q, buf);
 666                 buf->state = VIDEOBUF_IDLE;
 667                 break;
 668         case VIDEOBUF_DONE:
 669                 dprintk(1, "dqbuf: state is done\n");
 670                 CALL(q, sync, q, buf);
 671                 buf->state = VIDEOBUF_IDLE;
 672                 break;
 673         default:
 674                 dprintk(1, "dqbuf: state invalid\n");
 675                 retval = -EINVAL;
 676                 goto done;
 677         }
 678         list_del(&buf->stream);
 679         memset(b, 0, sizeof(*b));
 680         videobuf_status(q, b, buf, q->type);
 681
 682  done:
 683         mutex_unlock(&q->vb_lock);
 684         return retval;
 685 }
 686
 687 int videobuf_streamon(struct videobuf_queue *q)
 688 {
 689         struct videobuf_buffer *buf;
 690         unsigned long flags = 0;
 691         int retval;
 692
 693         mutex_lock(&q->vb_lock);
 694         retval = -EBUSY;
 695         if (q->reading)
 696                 goto done;
 697         retval = 0;
 698         if (q->streaming)
 699                 goto done;
 700         q->streaming = 1;
 701         spin_lock_irqsave(q->irqlock, flags);
 702         list_for_each_entry(buf, &q->stream, stream)
 703                 if (buf->state == VIDEOBUF_PREPARED)
 704                         q->ops->buf_queue(q, buf);
 705         spin_unlock_irqrestore(q->irqlock, flags);
 706
 707         wake_up_interruptible_sync(&q->wait);
 708  done:
 709         mutex_unlock(&q->vb_lock);
 710         return retval;
 711 }
 712
 713 /* Locking: Caller holds q->vb_lock */
 714 static int __videobuf_streamoff(struct videobuf_queue *q)
 715 {
 716         if (!q->streaming)
 717                 return -EINVAL;
 718
 719         videobuf_queue_cancel(q);
 720
 721         return 0;
 722 }
 723
 724 int videobuf_streamoff(struct videobuf_queue *q)
 725 {
 726         int retval;
 727
 728         mutex_lock(&q->vb_lock);
 729         retval = __videobuf_streamoff(q);
 730         mutex_unlock(&q->vb_lock);
 731
 732         return retval;
 733 }
 734
 735 /* Locking: Caller holds q->vb_lock */
 736 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
 737                                       char __user *data,
 738                                       size_t count, loff_t *ppos)
 739 {
 740         enum v4l2_field field;
 741         unsigned long flags = 0;
 742         int retval;
 743
 744         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 745
 746         /* setup stuff */
 747         q->read_buf = videobuf_alloc(q);
 748         if (NULL == q->read_buf)
 749                 return -ENOMEM;
 750
 751         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 752         q->read_buf->baddr  = (unsigned long)data;
 753         q->read_buf->bsize  = count;
 754
 755         field = videobuf_next_field(q);
 756         retval = q->ops->buf_prepare(q, q->read_buf, field);
 757         if (0 != retval)
 758                 goto done;
 759
 760         /* start capture & wait */
 761         spin_lock_irqsave(q->irqlock, flags);
 762         q->ops->buf_queue(q, q->read_buf);
 763         spin_unlock_irqrestore(q->irqlock, flags);
 764         retval = videobuf_waiton(q->read_buf, 0, 0);
 765         if (0 == retval) {
 766                 CALL(q, sync, q, q->read_buf);
 767                 if (VIDEOBUF_ERROR == q->read_buf->state)
 768                         retval = -EIO;
 769                 else
 770                         retval = q->read_buf->size;
 771         }
 772
 773  done:
 774         /* cleanup */
 775         q->ops->buf_release(q, q->read_buf);
 776         kfree(q->read_buf);
 777         q->read_buf = NULL;
 778         return retval;
 779 }
 780
 781 ssize_t videobuf_read_one(struct videobuf_queue *q,
 782                           char __user *data, size_t count, loff_t *ppos,
 783                           int nonblocking)
 784 {
 785         enum v4l2_field field;
 786         unsigned long flags = 0;
 787         unsigned size = 0, nbufs = 1;
 788         int retval;
 789
 790         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 791
 792         mutex_lock(&q->vb_lock);
 793
 794         q->ops->buf_setup(q, &nbufs, &size);
 795
 796         if (NULL == q->read_buf  &&
 797             count >= size        &&
 798             !nonblocking) {
 799                 retval = videobuf_read_zerocopy(q, data, count, ppos);
 800                 if (retval >= 0  ||  retval == -EIO)
 801                         /* ok, all done */
 802                         goto done;
 803                 /* fallback to kernel bounce buffer on failures */
 804         }
 805
 806         if (NULL == q->read_buf) {
 807                 /* need to capture a new frame */
 808                 retval = -ENOMEM;
 809                 q->read_buf = videobuf_alloc(q);
 810
 811                 dprintk(1, "video alloc=0x%p\n", q->read_buf);
 812                 if (NULL == q->read_buf)
 813                         goto done;
 814                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 815                 q->read_buf->bsize = count; /* preferred size */
 816                 field = videobuf_next_field(q);
 817                 retval = q->ops->buf_prepare(q, q->read_buf, field);
 818
 819                 if (0 != retval) {
 820                         kfree(q->read_buf);
 821                         q->read_buf = NULL;
 822                         goto done;
 823                 }
 824
 825                 spin_lock_irqsave(q->irqlock, flags);
 826                 q->ops->buf_queue(q, q->read_buf);
 827                 spin_unlock_irqrestore(q->irqlock, flags);
 828
 829                 q->read_off = 0;
 830         }
 831
 832         /* wait until capture is done */
 833         retval = videobuf_waiton(q->read_buf, nonblocking, 1);
 834         if (0 != retval)
 835                 goto done;
 836
 837         CALL(q, sync, q, q->read_buf);
 838
 839         if (VIDEOBUF_ERROR == q->read_buf->state) {
 840                 /* catch I/O errors */
 841                 q->ops->buf_release(q, q->read_buf);
 842                 kfree(q->read_buf);
 843                 q->read_buf = NULL;
 844                 retval = -EIO;
 845                 goto done;
 846         }
 847
 848         /* Copy to userspace */
 849         retval = CALL(q, video_copy_to_user, q, data, count, nonblocking);
 850         if (retval < 0)
 851                 goto done;
 852
 853         q->read_off += retval;
 854         if (q->read_off == q->read_buf->size) {
 855                 /* all data copied, cleanup */
 856                 q->ops->buf_release(q, q->read_buf);
 857                 kfree(q->read_buf);
 858                 q->read_buf = NULL;
 859         }
 860
 861  done:
 862         mutex_unlock(&q->vb_lock);
 863         return retval;
 864 }
 865
 866 /* Locking: Caller holds q->vb_lock */
 867 static int __videobuf_read_start(struct videobuf_queue *q)
 868 {
 869         enum v4l2_field field;
 870         unsigned long flags = 0;
 871         unsigned int count = 0, size = 0;
 872         int err, i;
 873
 874         q->ops->buf_setup(q, &count, &size);
 875         if (count < 2)
 876                 count = 2;
 877         if (count > VIDEO_MAX_FRAME)
 878                 count = VIDEO_MAX_FRAME;
 879         size = PAGE_ALIGN(size);
 880
 881         err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
 882         if (err < 0)
 883                 return err;
 884
 885         count = err;
 886
 887         for (i = 0; i < count; i++) {
 888                 field = videobuf_next_field(q);
 889                 err = q->ops->buf_prepare(q, q->bufs[i], field);
 890                 if (err)
 891                         return err;
 892                 list_add_tail(&q->bufs[i]->stream, &q->stream);
 893         }
 894         spin_lock_irqsave(q->irqlock, flags);
 895         for (i = 0; i < count; i++)
 896                 q->ops->buf_queue(q, q->bufs[i]);
 897         spin_unlock_irqrestore(q->irqlock, flags);
 898         q->reading = 1;
 899         return 0;
 900 }
 901
 902 static void __videobuf_read_stop(struct videobuf_queue *q)
 903 {
 904         int i;
 905
 906         videobuf_queue_cancel(q);
 907         __videobuf_mmap_free(q);
 908         INIT_LIST_HEAD(&q->stream);
 909         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 910                 if (NULL == q->bufs[i])
 911                         continue;
 912                 kfree(q->bufs[i]);
 913                 q->bufs[i] = NULL;
 914         }
 915         q->read_buf = NULL;
 916
 917 }
 918
 919 int videobuf_read_start(struct videobuf_queue *q)
 920 {
 921         int rc;
 922
 923         mutex_lock(&q->vb_lock);
 924         rc = __videobuf_read_start(q);
 925         mutex_unlock(&q->vb_lock);
 926
 927         return rc;
 928 }
 929
 930 void videobuf_read_stop(struct videobuf_queue *q)
 931 {
 932         mutex_lock(&q->vb_lock);
 933         __videobuf_read_stop(q);
 934         mutex_unlock(&q->vb_lock);
 935 }
 936
 937 void videobuf_stop(struct videobuf_queue *q)
 938 {
 939         mutex_lock(&q->vb_lock);
 940
 941         if (q->streaming)
 942                 __videobuf_streamoff(q);
 943
 944         if (q->reading)
 945                 __videobuf_read_stop(q);
 946
 947         mutex_unlock(&q->vb_lock);
 948 }
 949
 950
 951 ssize_t videobuf_read_stream(struct videobuf_queue *q,
 952                              char __user *data, size_t count, loff_t *ppos,
 953                              int vbihack, int nonblocking)
 954 {
 955         int rc, retval;
 956         unsigned long flags = 0;
 957
 958         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 959
 960         dprintk(2, "%s\n", __func__);
 961         mutex_lock(&q->vb_lock);
 962         retval = -EBUSY;
 963         if (q->streaming)
 964                 goto done;
 965         if (!q->reading) {
 966                 retval = __videobuf_read_start(q);
 967                 if (retval < 0)
 968                         goto done;
 969         }
 970
 971         retval = 0;
 972         while (count > 0) {
 973                 /* get / wait for data */
 974                 if (NULL == q->read_buf) {
 975                         q->read_buf = list_entry(q->stream.next,
 976                                                  struct videobuf_buffer,
 977                                                  stream);
 978                         list_del(&q->read_buf->stream);
 979                         q->read_off = 0;
 980                 }
 981                 rc = videobuf_waiton(q->read_buf, nonblocking, 1);
 982                 if (rc < 0) {
 983                         if (0 == retval)
 984                                 retval = rc;
 985                         break;
 986                 }
 987
 988                 if (q->read_buf->state == VIDEOBUF_DONE) {
 989                         rc = CALL(q, copy_stream, q, data + retval, count,
 990                                         retval, vbihack, nonblocking);
 991                         if (rc < 0) {
 992                                 retval = rc;
 993                                 break;
 994                         }
 995                         retval      += rc;
 996                         count       -= rc;
 997                         q->read_off += rc;
 998                 } else {
 999                         /* some error */
1000                         q->read_off = q->read_buf->size;
1001                         if (0 == retval)
1002                                 retval = -EIO;
1003                 }
1004
1005                 /* requeue buffer when done with copying */
1006                 if (q->read_off == q->read_buf->size) {
1007                         list_add_tail(&q->read_buf->stream,
1008                                       &q->stream);
1009                         spin_lock_irqsave(q->irqlock, flags);
1010                         q->ops->buf_queue(q, q->read_buf);
1011                         spin_unlock_irqrestore(q->irqlock, flags);
1012                         q->read_buf = NULL;
1013                 }
1014                 if (retval < 0)
1015                         break;
1016         }
1017
1018  done:
1019         mutex_unlock(&q->vb_lock);
1020         return retval;
1021 }
1022
1023 unsigned int videobuf_poll_stream(struct file *file,
1024                                   struct videobuf_queue *q,
1025                                   poll_table *wait)
1026 {
1027         struct videobuf_buffer *buf = NULL;
1028         unsigned int rc = 0;
1029
1030         mutex_lock(&q->vb_lock);
1031         if (q->streaming) {
1032                 if (!list_empty(&q->stream))
1033                         buf = list_entry(q->stream.next,
1034                                          struct videobuf_buffer, stream);
1035         } else {
1036                 if (!q->reading)
1037                         __videobuf_read_start(q);
1038                 if (!q->reading) {
1039                         rc = POLLERR;
1040                 } else if (NULL == q->read_buf) {
1041                         q->read_buf = list_entry(q->stream.next,
1042                                                  struct videobuf_buffer,
1043                                                  stream);
1044                         list_del(&q->read_buf->stream);
1045                         q->read_off = 0;
1046                 }
1047                 buf = q->read_buf;
1048         }
1049         if (!buf)
1050                 rc = POLLERR;
1051
1052         if (0 == rc) {
1053                 poll_wait(file, &buf->done, wait);
1054                 if (buf->state == VIDEOBUF_DONE ||
1055                     buf->state == VIDEOBUF_ERROR)
1056                         rc = POLLIN|POLLRDNORM;
1057         }
1058         mutex_unlock(&q->vb_lock);
1059         return rc;
1060 }
1061
1062 int videobuf_mmap_mapper(struct videobuf_queue *q,
1063                          struct vm_area_struct *vma)
1064 {
1065         int retval;
1066
1067         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1068
1069         mutex_lock(&q->vb_lock);
1070         retval = CALL(q, mmap_mapper, q, vma);
1071         q->is_mmapped = 1;
1072         mutex_unlock(&q->vb_lock);
1073
1074         return retval;
1075 }
1076
1077 #ifdef CONFIG_VIDEO_V4L1_COMPAT
1078 int videobuf_cgmbuf(struct videobuf_queue *q,
1079                     struct video_mbuf *mbuf, int count)
1080 {
1081         struct v4l2_requestbuffers req;
1082         int rc, i;
1083
1084         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1085
1086         memset(&req, 0, sizeof(req));
1087         req.type   = q->type;
1088         req.count  = count;
1089         req.memory = V4L2_MEMORY_MMAP;
1090         rc = videobuf_reqbufs(q, &req);
1091         if (rc < 0)
1092                 return rc;
1093
1094         mbuf->frames = req.count;
1095         mbuf->size   = 0;
1096         for (i = 0; i < mbuf->frames; i++) {
1097                 mbuf->offsets[i]  = q->bufs[i]->boff;
1098                 mbuf->size       += q->bufs[i]->bsize;
1099         }
1100
1101         return 0;
1102 }
1103 EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
1104 #endif
1105
1106 /* --------------------------------------------------------------------- */
1107
1108 EXPORT_SYMBOL_GPL(videobuf_waiton);
1109 EXPORT_SYMBOL_GPL(videobuf_iolock);
1110
1111 EXPORT_SYMBOL_GPL(videobuf_alloc);
1112
1113 EXPORT_SYMBOL_GPL(videobuf_queue_core_init);
1114 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
1115 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
1116
1117 EXPORT_SYMBOL_GPL(videobuf_next_field);
1118 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
1119 EXPORT_SYMBOL_GPL(videobuf_querybuf);
1120 EXPORT_SYMBOL_GPL(videobuf_qbuf);
1121 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
1122 EXPORT_SYMBOL_GPL(videobuf_streamon);
1123 EXPORT_SYMBOL_GPL(videobuf_streamoff);
1124
1125 EXPORT_SYMBOL_GPL(videobuf_read_start);
1126 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1127 EXPORT_SYMBOL_GPL(videobuf_stop);
1128 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1129 EXPORT_SYMBOL_GPL(videobuf_read_one);
1130 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1131
1132 EXPORT_SYMBOL_GPL(__videobuf_mmap_setup);
1133 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
1134 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
1135 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);