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 struct videobuf_buffer *videobuf_alloc_vb(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_vb) {
  62                 printk(KERN_ERR "No specific ops defined!\n");
  63                 BUG();
  64         }
  65
  66         vb = q->int_ops->alloc_vb(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_vb);
  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_vaddr(struct videobuf_queue *q,
 109                               struct videobuf_buffer *buf)
 110 {
 111         if (q->int_ops->vaddr)
 112                 return q->int_ops->vaddr(buf);
 113         return NULL;
 114 }
 115 EXPORT_SYMBOL_GPL(videobuf_queue_to_vaddr);
 116
 117 /* --------------------------------------------------------------------- */
 118
 119
 120 void videobuf_queue_core_init(struct videobuf_queue *q,
 121                          const struct videobuf_queue_ops *ops,
 122                          struct device *dev,
 123                          spinlock_t *irqlock,
 124                          enum v4l2_buf_type type,
 125                          enum v4l2_field field,
 126                          unsigned int msize,
 127                          void *priv,
 128                          struct videobuf_qtype_ops *int_ops)
 129 {
 130         BUG_ON(!q);
 131         memset(q, 0, sizeof(*q));
 132         q->irqlock   = irqlock;
 133         q->dev       = dev;
 134         q->type      = type;
 135         q->field     = field;
 136         q->msize     = msize;
 137         q->ops       = ops;
 138         q->priv_data = priv;
 139         q->int_ops   = int_ops;
 140
 141         /* All buffer operations are mandatory */
 142         BUG_ON(!q->ops->buf_setup);
 143         BUG_ON(!q->ops->buf_prepare);
 144         BUG_ON(!q->ops->buf_queue);
 145         BUG_ON(!q->ops->buf_release);
 146
 147         /* Lock is mandatory for queue_cancel to work */
 148         BUG_ON(!irqlock);
 149
 150         /* Having implementations for abstract methods are mandatory */
 151         BUG_ON(!q->int_ops);
 152
 153         mutex_init(&q->vb_lock);
 154         init_waitqueue_head(&q->wait);
 155         INIT_LIST_HEAD(&q->stream);
 156 }
 157 EXPORT_SYMBOL_GPL(videobuf_queue_core_init);
 158
 159 /* Locking: Only usage in bttv unsafe find way to remove */
 160 int videobuf_queue_is_busy(struct videobuf_queue *q)
 161 {
 162         int i;
 163
 164         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 165
 166         if (q->streaming) {
 167                 dprintk(1, "busy: streaming active\n");
 168                 return 1;
 169         }
 170         if (q->reading) {
 171                 dprintk(1, "busy: pending read #1\n");
 172                 return 1;
 173         }
 174         if (q->read_buf) {
 175                 dprintk(1, "busy: pending read #2\n");
 176                 return 1;
 177         }
 178         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 179                 if (NULL == q->bufs[i])
 180                         continue;
 181                 if (q->bufs[i]->map) {
 182                         dprintk(1, "busy: buffer #%d mapped\n", i);
 183                         return 1;
 184                 }
 185                 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
 186                         dprintk(1, "busy: buffer #%d queued\n", i);
 187                         return 1;
 188                 }
 189                 if (q->bufs[i]->state == VIDEOBUF_ACTIVE) {
 190                         dprintk(1, "busy: buffer #%d avtive\n", i);
 191                         return 1;
 192                 }
 193         }
 194         return 0;
 195 }
 196 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
 197
 198 /**
 199  * __videobuf_free() - free all the buffers and their control structures
 200  *
 201  * This function can only be called if streaming/reading is off, i.e. no buffers
 202  * are under control of the driver.
 203  */
 204 /* Locking: Caller holds q->vb_lock */
 205 static int __videobuf_free(struct videobuf_queue *q)
 206 {
 207         int i;
 208
 209         dprintk(1, "%s\n", __func__);
 210         if (!q)
 211                 return 0;
 212
 213         if (q->streaming || q->reading) {
 214                 dprintk(1, "Cannot free buffers when streaming or reading\n");
 215                 return -EBUSY;
 216         }
 217
 218         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 219
 220         for (i = 0; i < VIDEO_MAX_FRAME; i++)
 221                 if (q->bufs[i] && q->bufs[i]->map) {
 222                         dprintk(1, "Cannot free mmapped buffers\n");
 223                         return -EBUSY;
 224                 }
 225
 226         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 227                 if (NULL == q->bufs[i])
 228                         continue;
 229                 q->ops->buf_release(q, q->bufs[i]);
 230                 kfree(q->bufs[i]);
 231                 q->bufs[i] = NULL;
 232         }
 233
 234         return 0;
 235 }
 236
 237 /* Locking: Caller holds q->vb_lock */
 238 void videobuf_queue_cancel(struct videobuf_queue *q)
 239 {
 240         unsigned long flags = 0;
 241         int i;
 242
 243         q->streaming = 0;
 244         q->reading  = 0;
 245         wake_up_interruptible_sync(&q->wait);
 246
 247         /* remove queued buffers from list */
 248         spin_lock_irqsave(q->irqlock, flags);
 249         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 250                 if (NULL == q->bufs[i])
 251                         continue;
 252                 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
 253                         list_del(&q->bufs[i]->queue);
 254                         q->bufs[i]->state = VIDEOBUF_ERROR;
 255                         wake_up_all(&q->bufs[i]->done);
 256                 }
 257         }
 258         spin_unlock_irqrestore(q->irqlock, flags);
 259
 260         /* free all buffers + clear queue */
 261         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 262                 if (NULL == q->bufs[i])
 263                         continue;
 264                 q->ops->buf_release(q, q->bufs[i]);
 265         }
 266         INIT_LIST_HEAD(&q->stream);
 267 }
 268 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
 269
 270 /* --------------------------------------------------------------------- */
 271
 272 /* Locking: Caller holds q->vb_lock */
 273 enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
 274 {
 275         enum v4l2_field field = q->field;
 276
 277         BUG_ON(V4L2_FIELD_ANY == field);
 278
 279         if (V4L2_FIELD_ALTERNATE == field) {
 280                 if (V4L2_FIELD_TOP == q->last) {
 281                         field   = V4L2_FIELD_BOTTOM;
 282                         q->last = V4L2_FIELD_BOTTOM;
 283                 } else {
 284                         field   = V4L2_FIELD_TOP;
 285                         q->last = V4L2_FIELD_TOP;
 286                 }
 287         }
 288         return field;
 289 }
 290 EXPORT_SYMBOL_GPL(videobuf_next_field);
 291
 292 /* Locking: Caller holds q->vb_lock */
 293 static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
 294                             struct videobuf_buffer *vb, enum v4l2_buf_type type)
 295 {
 296         MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
 297         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 298
 299         b->index    = vb->i;
 300         b->type     = type;
 301
 302         b->memory   = vb->memory;
 303         switch (b->memory) {
 304         case V4L2_MEMORY_MMAP:
 305                 b->m.offset  = vb->boff;
 306                 b->length    = vb->bsize;
 307                 break;
 308         case V4L2_MEMORY_USERPTR:
 309                 b->m.userptr = vb->baddr;
 310                 b->length    = vb->bsize;
 311                 break;
 312         case V4L2_MEMORY_OVERLAY:
 313                 b->m.offset  = vb->boff;
 314                 break;
 315         }
 316
 317         b->flags    = 0;
 318         if (vb->map)
 319                 b->flags |= V4L2_BUF_FLAG_MAPPED;
 320
 321         switch (vb->state) {
 322         case VIDEOBUF_PREPARED:
 323         case VIDEOBUF_QUEUED:
 324         case VIDEOBUF_ACTIVE:
 325                 b->flags |= V4L2_BUF_FLAG_QUEUED;
 326                 break;
 327         case VIDEOBUF_ERROR:
 328                 b->flags |= V4L2_BUF_FLAG_ERROR;
 329                 /* fall through */
 330         case VIDEOBUF_DONE:
 331                 b->flags |= V4L2_BUF_FLAG_DONE;
 332                 break;
 333         case VIDEOBUF_NEEDS_INIT:
 334         case VIDEOBUF_IDLE:
 335                 /* nothing */
 336                 break;
 337         }
 338
 339         if (vb->input != UNSET) {
 340                 b->flags |= V4L2_BUF_FLAG_INPUT;
 341                 b->input  = vb->input;
 342         }
 343
 344         b->field     = vb->field;
 345         b->timestamp = vb->ts;
 346         b->bytesused = vb->size;
 347         b->sequence  = vb->field_count >> 1;
 348 }
 349
 350 int videobuf_mmap_free(struct videobuf_queue *q)
 351 {
 352         int ret;
 353         mutex_lock(&q->vb_lock);
 354         ret = __videobuf_free(q);
 355         mutex_unlock(&q->vb_lock);
 356         return ret;
 357 }
 358 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
 359
 360 /* Locking: Caller holds q->vb_lock */
 361 int __videobuf_mmap_setup(struct videobuf_queue *q,
 362                         unsigned int bcount, unsigned int bsize,
 363                         enum v4l2_memory memory)
 364 {
 365         unsigned int i;
 366         int err;
 367
 368         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 369
 370         err = __videobuf_free(q);
 371         if (0 != err)
 372                 return err;
 373
 374         /* Allocate and initialize buffers */
 375         for (i = 0; i < bcount; i++) {
 376                 q->bufs[i] = videobuf_alloc_vb(q);
 377
 378                 if (NULL == q->bufs[i])
 379                         break;
 380
 381                 q->bufs[i]->i      = i;
 382                 q->bufs[i]->input  = UNSET;
 383                 q->bufs[i]->memory = memory;
 384                 q->bufs[i]->bsize  = bsize;
 385                 switch (memory) {
 386                 case V4L2_MEMORY_MMAP:
 387                         q->bufs[i]->boff = PAGE_ALIGN(bsize) * i;
 388                         break;
 389                 case V4L2_MEMORY_USERPTR:
 390                 case V4L2_MEMORY_OVERLAY:
 391                         /* nothing */
 392                         break;
 393                 }
 394         }
 395
 396         if (!i)
 397                 return -ENOMEM;
 398
 399         dprintk(1, "mmap setup: %d buffers, %d bytes each\n", i, bsize);
 400
 401         return i;
 402 }
 403 EXPORT_SYMBOL_GPL(__videobuf_mmap_setup);
 404
 405 int videobuf_mmap_setup(struct videobuf_queue *q,
 406                         unsigned int bcount, unsigned int bsize,
 407                         enum v4l2_memory memory)
 408 {
 409         int ret;
 410         mutex_lock(&q->vb_lock);
 411         ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
 412         mutex_unlock(&q->vb_lock);
 413         return ret;
 414 }
 415 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
 416
 417 int videobuf_reqbufs(struct videobuf_queue *q,
 418                  struct v4l2_requestbuffers *req)
 419 {
 420         unsigned int size, count;
 421         int retval;
 422
 423         if (req->count < 1) {
 424                 dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
 425                 return -EINVAL;
 426         }
 427
 428         if (req->memory != V4L2_MEMORY_MMAP     &&
 429             req->memory != V4L2_MEMORY_USERPTR  &&
 430             req->memory != V4L2_MEMORY_OVERLAY) {
 431                 dprintk(1, "reqbufs: memory type invalid\n");
 432                 return -EINVAL;
 433         }
 434
 435         mutex_lock(&q->vb_lock);
 436         if (req->type != q->type) {
 437                 dprintk(1, "reqbufs: queue type invalid\n");
 438                 retval = -EINVAL;
 439                 goto done;
 440         }
 441
 442         if (q->streaming) {
 443                 dprintk(1, "reqbufs: streaming already exists\n");
 444                 retval = -EBUSY;
 445                 goto done;
 446         }
 447         if (!list_empty(&q->stream)) {
 448                 dprintk(1, "reqbufs: stream running\n");
 449                 retval = -EBUSY;
 450                 goto done;
 451         }
 452
 453         count = req->count;
 454         if (count > VIDEO_MAX_FRAME)
 455                 count = VIDEO_MAX_FRAME;
 456         size = 0;
 457         q->ops->buf_setup(q, &count, &size);
 458         dprintk(1, "reqbufs: bufs=%d, size=0x%x [%u pages total]\n",
 459                 count, size,
 460                 (unsigned int)((count * PAGE_ALIGN(size)) >> PAGE_SHIFT));
 461
 462         retval = __videobuf_mmap_setup(q, count, size, req->memory);
 463         if (retval < 0) {
 464                 dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
 465                 goto done;
 466         }
 467
 468         req->count = retval;
 469         retval = 0;
 470
 471  done:
 472         mutex_unlock(&q->vb_lock);
 473         return retval;
 474 }
 475 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
 476
 477 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 478 {
 479         int ret = -EINVAL;
 480
 481         mutex_lock(&q->vb_lock);
 482         if (unlikely(b->type != q->type)) {
 483                 dprintk(1, "querybuf: Wrong type.\n");
 484                 goto done;
 485         }
 486         if (unlikely(b->index >= VIDEO_MAX_FRAME)) {
 487                 dprintk(1, "querybuf: index out of range.\n");
 488                 goto done;
 489         }
 490         if (unlikely(NULL == q->bufs[b->index])) {
 491                 dprintk(1, "querybuf: buffer is null.\n");
 492                 goto done;
 493         }
 494
 495         videobuf_status(q, b, q->bufs[b->index], q->type);
 496
 497         ret = 0;
 498 done:
 499         mutex_unlock(&q->vb_lock);
 500         return ret;
 501 }
 502 EXPORT_SYMBOL_GPL(videobuf_querybuf);
 503
 504 int videobuf_qbuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 505 {
 506         struct videobuf_buffer *buf;
 507         enum v4l2_field field;
 508         unsigned long flags = 0;
 509         int retval;
 510
 511         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 512
 513         if (b->memory == V4L2_MEMORY_MMAP)
 514                 down_read(&current->mm->mmap_sem);
 515
 516         mutex_lock(&q->vb_lock);
 517         retval = -EBUSY;
 518         if (q->reading) {
 519                 dprintk(1, "qbuf: Reading running...\n");
 520                 goto done;
 521         }
 522         retval = -EINVAL;
 523         if (b->type != q->type) {
 524                 dprintk(1, "qbuf: Wrong type.\n");
 525                 goto done;
 526         }
 527         if (b->index >= VIDEO_MAX_FRAME) {
 528                 dprintk(1, "qbuf: index out of range.\n");
 529                 goto done;
 530         }
 531         buf = q->bufs[b->index];
 532         if (NULL == buf) {
 533                 dprintk(1, "qbuf: buffer is null.\n");
 534                 goto done;
 535         }
 536         MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
 537         if (buf->memory != b->memory) {
 538                 dprintk(1, "qbuf: memory type is wrong.\n");
 539                 goto done;
 540         }
 541         if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
 542                 dprintk(1, "qbuf: buffer is already queued or active.\n");
 543                 goto done;
 544         }
 545
 546         if (b->flags & V4L2_BUF_FLAG_INPUT) {
 547                 if (b->input >= q->inputs) {
 548                         dprintk(1, "qbuf: wrong input.\n");
 549                         goto done;
 550                 }
 551                 buf->input = b->input;
 552         } else {
 553                 buf->input = UNSET;
 554         }
 555
 556         switch (b->memory) {
 557         case V4L2_MEMORY_MMAP:
 558                 if (0 == buf->baddr) {
 559                         dprintk(1, "qbuf: mmap requested "
 560                                    "but buffer addr is zero!\n");
 561                         goto done;
 562                 }
 563                 if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT
 564                     || q->type == V4L2_BUF_TYPE_VBI_OUTPUT
 565                     || q->type == V4L2_BUF_TYPE_SLICED_VBI_OUTPUT) {
 566                         buf->size = b->bytesused;
 567                         buf->field = b->field;
 568                         buf->ts = b->timestamp;
 569                 }
 570                 break;
 571         case V4L2_MEMORY_USERPTR:
 572                 if (b->length < buf->bsize) {
 573                         dprintk(1, "qbuf: buffer length is not enough\n");
 574                         goto done;
 575                 }
 576                 if (VIDEOBUF_NEEDS_INIT != buf->state &&
 577                     buf->baddr != b->m.userptr)
 578                         q->ops->buf_release(q, buf);
 579                 buf->baddr = b->m.userptr;
 580                 break;
 581         case V4L2_MEMORY_OVERLAY:
 582                 buf->boff = b->m.offset;
 583                 break;
 584         default:
 585                 dprintk(1, "qbuf: wrong memory type\n");
 586                 goto done;
 587         }
 588
 589         dprintk(1, "qbuf: requesting next field\n");
 590         field = videobuf_next_field(q);
 591         retval = q->ops->buf_prepare(q, buf, field);
 592         if (0 != retval) {
 593                 dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
 594                 goto done;
 595         }
 596
 597         list_add_tail(&buf->stream, &q->stream);
 598         if (q->streaming) {
 599                 spin_lock_irqsave(q->irqlock, flags);
 600                 q->ops->buf_queue(q, buf);
 601                 spin_unlock_irqrestore(q->irqlock, flags);
 602         }
 603         dprintk(1, "qbuf: succeeded\n");
 604         retval = 0;
 605         wake_up_interruptible_sync(&q->wait);
 606
 607 done:
 608         mutex_unlock(&q->vb_lock);
 609
 610         if (b->memory == V4L2_MEMORY_MMAP)
 611                 up_read(&current->mm->mmap_sem);
 612
 613         return retval;
 614 }
 615 EXPORT_SYMBOL_GPL(videobuf_qbuf);
 616
 617 /* Locking: Caller holds q->vb_lock */
 618 static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
 619 {
 620         int retval;
 621
 622 checks:
 623         if (!q->streaming) {
 624                 dprintk(1, "next_buffer: Not streaming\n");
 625                 retval = -EINVAL;
 626                 goto done;
 627         }
 628
 629         if (list_empty(&q->stream)) {
 630                 if (noblock) {
 631                         retval = -EAGAIN;
 632                         dprintk(2, "next_buffer: no buffers to dequeue\n");
 633                         goto done;
 634                 } else {
 635                         dprintk(2, "next_buffer: waiting on buffer\n");
 636
 637                         /* Drop lock to avoid deadlock with qbuf */
 638                         mutex_unlock(&q->vb_lock);
 639
 640                         /* Checking list_empty and streaming is safe without
 641                          * locks because we goto checks to validate while
 642                          * holding locks before proceeding */
 643                         retval = wait_event_interruptible(q->wait,
 644                                 !list_empty(&q->stream) || !q->streaming);
 645                         mutex_lock(&q->vb_lock);
 646
 647                         if (retval)
 648                                 goto done;
 649
 650                         goto checks;
 651                 }
 652         }
 653
 654         retval = 0;
 655
 656 done:
 657         return retval;
 658 }
 659
 660 /* Locking: Caller holds q->vb_lock */
 661 static int stream_next_buffer(struct videobuf_queue *q,
 662                         struct videobuf_buffer **vb, int nonblocking)
 663 {
 664         int retval;
 665         struct videobuf_buffer *buf = NULL;
 666
 667         retval = stream_next_buffer_check_queue(q, nonblocking);
 668         if (retval)
 669                 goto done;
 670
 671         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
 672         retval = videobuf_waiton(buf, nonblocking, 1);
 673         if (retval < 0)
 674                 goto done;
 675
 676         *vb = buf;
 677 done:
 678         return retval;
 679 }
 680
 681 int videobuf_dqbuf(struct videobuf_queue *q,
 682                    struct v4l2_buffer *b, int nonblocking)
 683 {
 684         struct videobuf_buffer *buf = NULL;
 685         int retval;
 686
 687         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 688
 689         memset(b, 0, sizeof(*b));
 690         mutex_lock(&q->vb_lock);
 691
 692         retval = stream_next_buffer(q, &buf, nonblocking);
 693         if (retval < 0) {
 694                 dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
 695                 goto done;
 696         }
 697
 698         switch (buf->state) {
 699         case VIDEOBUF_ERROR:
 700                 dprintk(1, "dqbuf: state is error\n");
 701                 break;
 702         case VIDEOBUF_DONE:
 703                 dprintk(1, "dqbuf: state is done\n");
 704                 break;
 705         default:
 706                 dprintk(1, "dqbuf: state invalid\n");
 707                 retval = -EINVAL;
 708                 goto done;
 709         }
 710         CALL(q, sync, q, buf);
 711         videobuf_status(q, b, buf, q->type);
 712         list_del(&buf->stream);
 713         buf->state = VIDEOBUF_IDLE;
 714         b->flags &= ~V4L2_BUF_FLAG_DONE;
 715 done:
 716         mutex_unlock(&q->vb_lock);
 717         return retval;
 718 }
 719 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
 720
 721 int videobuf_streamon(struct videobuf_queue *q)
 722 {
 723         struct videobuf_buffer *buf;
 724         unsigned long flags = 0;
 725         int retval;
 726
 727         mutex_lock(&q->vb_lock);
 728         retval = -EBUSY;
 729         if (q->reading)
 730                 goto done;
 731         retval = 0;
 732         if (q->streaming)
 733                 goto done;
 734         q->streaming = 1;
 735         spin_lock_irqsave(q->irqlock, flags);
 736         list_for_each_entry(buf, &q->stream, stream)
 737                 if (buf->state == VIDEOBUF_PREPARED)
 738                         q->ops->buf_queue(q, buf);
 739         spin_unlock_irqrestore(q->irqlock, flags);
 740
 741         wake_up_interruptible_sync(&q->wait);
 742 done:
 743         mutex_unlock(&q->vb_lock);
 744         return retval;
 745 }
 746 EXPORT_SYMBOL_GPL(videobuf_streamon);
 747
 748 /* Locking: Caller holds q->vb_lock */
 749 static int __videobuf_streamoff(struct videobuf_queue *q)
 750 {
 751         if (!q->streaming)
 752                 return -EINVAL;
 753
 754         videobuf_queue_cancel(q);
 755
 756         return 0;
 757 }
 758
 759 int videobuf_streamoff(struct videobuf_queue *q)
 760 {
 761         int retval;
 762
 763         mutex_lock(&q->vb_lock);
 764         retval = __videobuf_streamoff(q);
 765         mutex_unlock(&q->vb_lock);
 766
 767         return retval;
 768 }
 769 EXPORT_SYMBOL_GPL(videobuf_streamoff);
 770
 771 /* Locking: Caller holds q->vb_lock */
 772 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
 773                                       char __user *data,
 774                                       size_t count, loff_t *ppos)
 775 {
 776         enum v4l2_field field;
 777         unsigned long flags = 0;
 778         int retval;
 779
 780         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 781
 782         /* setup stuff */
 783         q->read_buf = videobuf_alloc_vb(q);
 784         if (NULL == q->read_buf)
 785                 return -ENOMEM;
 786
 787         q->read_buf->memory = V4L2_MEMORY_USERPTR;
 788         q->read_buf->baddr  = (unsigned long)data;
 789         q->read_buf->bsize  = count;
 790
 791         field = videobuf_next_field(q);
 792         retval = q->ops->buf_prepare(q, q->read_buf, field);
 793         if (0 != retval)
 794                 goto done;
 795
 796         /* start capture & wait */
 797         spin_lock_irqsave(q->irqlock, flags);
 798         q->ops->buf_queue(q, q->read_buf);
 799         spin_unlock_irqrestore(q->irqlock, flags);
 800         retval = videobuf_waiton(q->read_buf, 0, 0);
 801         if (0 == retval) {
 802                 CALL(q, sync, q, q->read_buf);
 803                 if (VIDEOBUF_ERROR == q->read_buf->state)
 804                         retval = -EIO;
 805                 else
 806                         retval = q->read_buf->size;
 807         }
 808
 809 done:
 810         /* cleanup */
 811         q->ops->buf_release(q, q->read_buf);
 812         kfree(q->read_buf);
 813         q->read_buf = NULL;
 814         return retval;
 815 }
 816
 817 static int __videobuf_copy_to_user(struct videobuf_queue *q,
 818                                    struct videobuf_buffer *buf,
 819                                    char __user *data, size_t count,
 820                                    int nonblocking)
 821 {
 822         void *vaddr = CALL(q, vaddr, buf);
 823
 824         /* copy to userspace */
 825         if (count > buf->size - q->read_off)
 826                 count = buf->size - q->read_off;
 827
 828         if (copy_to_user(data, vaddr + q->read_off, count))
 829                 return -EFAULT;
 830
 831         return count;
 832 }
 833
 834 static int __videobuf_copy_stream(struct videobuf_queue *q,
 835                                   struct videobuf_buffer *buf,
 836                                   char __user *data, size_t count, size_t pos,
 837                                   int vbihack, int nonblocking)
 838 {
 839         unsigned int *fc = CALL(q, vaddr, buf);
 840
 841         if (vbihack) {
 842                 /* dirty, undocumented hack -- pass the frame counter
 843                         * within the last four bytes of each vbi data block.
 844                         * We need that one to maintain backward compatibility
 845                         * to all vbi decoding software out there ... */
 846                 fc += (buf->size >> 2) - 1;
 847                 *fc = buf->field_count >> 1;
 848                 dprintk(1, "vbihack: %d\n", *fc);
 849         }
 850
 851         /* copy stuff using the common method */
 852         count = __videobuf_copy_to_user(q, buf, data, count, nonblocking);
 853
 854         if ((count == -EFAULT) && (pos == 0))
 855                 return -EFAULT;
 856
 857         return count;
 858 }
 859
 860 ssize_t videobuf_read_one(struct videobuf_queue *q,
 861                           char __user *data, size_t count, loff_t *ppos,
 862                           int nonblocking)
 863 {
 864         enum v4l2_field field;
 865         unsigned long flags = 0;
 866         unsigned size = 0, nbufs = 1;
 867         int retval;
 868
 869         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 870
 871         mutex_lock(&q->vb_lock);
 872
 873         q->ops->buf_setup(q, &nbufs, &size);
 874
 875         if (NULL == q->read_buf  &&
 876             count >= size        &&
 877             !nonblocking) {
 878                 retval = videobuf_read_zerocopy(q, data, count, ppos);
 879                 if (retval >= 0  ||  retval == -EIO)
 880                         /* ok, all done */
 881                         goto done;
 882                 /* fallback to kernel bounce buffer on failures */
 883         }
 884
 885         if (NULL == q->read_buf) {
 886                 /* need to capture a new frame */
 887                 retval = -ENOMEM;
 888                 q->read_buf = videobuf_alloc_vb(q);
 889
 890                 dprintk(1, "video alloc=0x%p\n", q->read_buf);
 891                 if (NULL == q->read_buf)
 892                         goto done;
 893                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
 894                 q->read_buf->bsize = count; /* preferred size */
 895                 field = videobuf_next_field(q);
 896                 retval = q->ops->buf_prepare(q, q->read_buf, field);
 897
 898                 if (0 != retval) {
 899                         kfree(q->read_buf);
 900                         q->read_buf = NULL;
 901                         goto done;
 902                 }
 903
 904                 spin_lock_irqsave(q->irqlock, flags);
 905                 q->ops->buf_queue(q, q->read_buf);
 906                 spin_unlock_irqrestore(q->irqlock, flags);
 907
 908                 q->read_off = 0;
 909         }
 910
 911         /* wait until capture is done */
 912         retval = videobuf_waiton(q->read_buf, nonblocking, 1);
 913         if (0 != retval)
 914                 goto done;
 915
 916         CALL(q, sync, q, q->read_buf);
 917
 918         if (VIDEOBUF_ERROR == q->read_buf->state) {
 919                 /* catch I/O errors */
 920                 q->ops->buf_release(q, q->read_buf);
 921                 kfree(q->read_buf);
 922                 q->read_buf = NULL;
 923                 retval = -EIO;
 924                 goto done;
 925         }
 926
 927         /* Copy to userspace */
 928         retval = __videobuf_copy_to_user(q, q->read_buf, data, count, nonblocking);
 929         if (retval < 0)
 930                 goto done;
 931
 932         q->read_off += retval;
 933         if (q->read_off == q->read_buf->size) {
 934                 /* all data copied, cleanup */
 935                 q->ops->buf_release(q, q->read_buf);
 936                 kfree(q->read_buf);
 937                 q->read_buf = NULL;
 938         }
 939
 940 done:
 941         mutex_unlock(&q->vb_lock);
 942         return retval;
 943 }
 944 EXPORT_SYMBOL_GPL(videobuf_read_one);
 945
 946 /* Locking: Caller holds q->vb_lock */
 947 static int __videobuf_read_start(struct videobuf_queue *q)
 948 {
 949         enum v4l2_field field;
 950         unsigned long flags = 0;
 951         unsigned int count = 0, size = 0;
 952         int err, i;
 953
 954         q->ops->buf_setup(q, &count, &size);
 955         if (count < 2)
 956                 count = 2;
 957         if (count > VIDEO_MAX_FRAME)
 958                 count = VIDEO_MAX_FRAME;
 959         size = PAGE_ALIGN(size);
 960
 961         err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
 962         if (err < 0)
 963                 return err;
 964
 965         count = err;
 966
 967         for (i = 0; i < count; i++) {
 968                 field = videobuf_next_field(q);
 969                 err = q->ops->buf_prepare(q, q->bufs[i], field);
 970                 if (err)
 971                         return err;
 972                 list_add_tail(&q->bufs[i]->stream, &q->stream);
 973         }
 974         spin_lock_irqsave(q->irqlock, flags);
 975         for (i = 0; i < count; i++)
 976                 q->ops->buf_queue(q, q->bufs[i]);
 977         spin_unlock_irqrestore(q->irqlock, flags);
 978         q->reading = 1;
 979         return 0;
 980 }
 981
 982 static void __videobuf_read_stop(struct videobuf_queue *q)
 983 {
 984         int i;
 985
 986         videobuf_queue_cancel(q);
 987         __videobuf_free(q);
 988         INIT_LIST_HEAD(&q->stream);
 989         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 990                 if (NULL == q->bufs[i])
 991                         continue;
 992                 kfree(q->bufs[i]);
 993                 q->bufs[i] = NULL;
 994         }
 995         q->read_buf = NULL;
 996 }
 997
 998 int videobuf_read_start(struct videobuf_queue *q)
 999 {
1000         int rc;
1001
1002         mutex_lock(&q->vb_lock);
1003         rc = __videobuf_read_start(q);
1004         mutex_unlock(&q->vb_lock);
1005
1006         return rc;
1007 }
1008 EXPORT_SYMBOL_GPL(videobuf_read_start);
1009
1010 void videobuf_read_stop(struct videobuf_queue *q)
1011 {
1012         mutex_lock(&q->vb_lock);
1013         __videobuf_read_stop(q);
1014         mutex_unlock(&q->vb_lock);
1015 }
1016 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1017
1018 void videobuf_stop(struct videobuf_queue *q)
1019 {
1020         mutex_lock(&q->vb_lock);
1021
1022         if (q->streaming)
1023                 __videobuf_streamoff(q);
1024
1025         if (q->reading)
1026                 __videobuf_read_stop(q);
1027
1028         mutex_unlock(&q->vb_lock);
1029 }
1030 EXPORT_SYMBOL_GPL(videobuf_stop);
1031
1032 ssize_t videobuf_read_stream(struct videobuf_queue *q,
1033                              char __user *data, size_t count, loff_t *ppos,
1034                              int vbihack, int nonblocking)
1035 {
1036         int rc, retval;
1037         unsigned long flags = 0;
1038
1039         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1040
1041         dprintk(2, "%s\n", __func__);
1042         mutex_lock(&q->vb_lock);
1043         retval = -EBUSY;
1044         if (q->streaming)
1045                 goto done;
1046         if (!q->reading) {
1047                 retval = __videobuf_read_start(q);
1048                 if (retval < 0)
1049                         goto done;
1050         }
1051
1052         retval = 0;
1053         while (count > 0) {
1054                 /* get / wait for data */
1055                 if (NULL == q->read_buf) {
1056                         q->read_buf = list_entry(q->stream.next,
1057                                                  struct videobuf_buffer,
1058                                                  stream);
1059                         list_del(&q->read_buf->stream);
1060                         q->read_off = 0;
1061                 }
1062                 rc = videobuf_waiton(q->read_buf, nonblocking, 1);
1063                 if (rc < 0) {
1064                         if (0 == retval)
1065                                 retval = rc;
1066                         break;
1067                 }
1068
1069                 if (q->read_buf->state == VIDEOBUF_DONE) {
1070                         rc = __videobuf_copy_stream(q, q->read_buf, data + retval, count,
1071                                         retval, vbihack, nonblocking);
1072                         if (rc < 0) {
1073                                 retval = rc;
1074                                 break;
1075                         }
1076                         retval      += rc;
1077                         count       -= rc;
1078                         q->read_off += rc;
1079                 } else {
1080                         /* some error */
1081                         q->read_off = q->read_buf->size;
1082                         if (0 == retval)
1083                                 retval = -EIO;
1084                 }
1085
1086                 /* requeue buffer when done with copying */
1087                 if (q->read_off == q->read_buf->size) {
1088                         list_add_tail(&q->read_buf->stream,
1089                                       &q->stream);
1090                         spin_lock_irqsave(q->irqlock, flags);
1091                         q->ops->buf_queue(q, q->read_buf);
1092                         spin_unlock_irqrestore(q->irqlock, flags);
1093                         q->read_buf = NULL;
1094                 }
1095                 if (retval < 0)
1096                         break;
1097         }
1098
1099 done:
1100         mutex_unlock(&q->vb_lock);
1101         return retval;
1102 }
1103 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1104
1105 unsigned int videobuf_poll_stream(struct file *file,
1106                                   struct videobuf_queue *q,
1107                                   poll_table *wait)
1108 {
1109         struct videobuf_buffer *buf = NULL;
1110         unsigned int rc = 0;
1111
1112         mutex_lock(&q->vb_lock);
1113         if (q->streaming) {
1114                 if (!list_empty(&q->stream))
1115                         buf = list_entry(q->stream.next,
1116                                          struct videobuf_buffer, stream);
1117         } else {
1118                 if (!q->reading)
1119                         __videobuf_read_start(q);
1120                 if (!q->reading) {
1121                         rc = POLLERR;
1122                 } else if (NULL == q->read_buf) {
1123                         q->read_buf = list_entry(q->stream.next,
1124                                                  struct videobuf_buffer,
1125                                                  stream);
1126                         list_del(&q->read_buf->stream);
1127                         q->read_off = 0;
1128                 }
1129                 buf = q->read_buf;
1130         }
1131         if (!buf)
1132                 rc = POLLERR;
1133
1134         if (0 == rc) {
1135                 poll_wait(file, &buf->done, wait);
1136                 if (buf->state == VIDEOBUF_DONE ||
1137                     buf->state == VIDEOBUF_ERROR) {
1138                         switch (q->type) {
1139                         case V4L2_BUF_TYPE_VIDEO_OUTPUT:
1140                         case V4L2_BUF_TYPE_VBI_OUTPUT:
1141                         case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
1142                                 rc = POLLOUT | POLLWRNORM;
1143                                 break;
1144                         default:
1145                                 rc = POLLIN | POLLRDNORM;
1146                                 break;
1147                         }
1148                 }
1149         }
1150         mutex_unlock(&q->vb_lock);
1151         return rc;
1152 }
1153 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1154
1155 int videobuf_mmap_mapper(struct videobuf_queue *q, struct vm_area_struct *vma)
1156 {
1157         int rc = -EINVAL;
1158         int i;
1159
1160         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1161
1162         if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED)) {
1163                 dprintk(1, "mmap appl bug: PROT_WRITE and MAP_SHARED are required\n");
1164                 return -EINVAL;
1165         }
1166
1167         mutex_lock(&q->vb_lock);
1168         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1169                 struct videobuf_buffer *buf = q->bufs[i];
1170
1171                 if (buf && buf->memory == V4L2_MEMORY_MMAP &&
1172                                 buf->boff == (vma->vm_pgoff << PAGE_SHIFT)) {
1173                         rc = CALL(q, mmap_mapper, q, buf, vma);
1174                         break;
1175                 }
1176         }
1177         mutex_unlock(&q->vb_lock);
1178
1179         return rc;
1180 }
1181 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
1182
1183 #ifdef CONFIG_VIDEO_V4L1_COMPAT
1184 int videobuf_cgmbuf(struct videobuf_queue *q,
1185                     struct video_mbuf *mbuf, int count)
1186 {
1187         struct v4l2_requestbuffers req;
1188         int rc, i;
1189
1190         MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1191
1192         memset(&req, 0, sizeof(req));
1193         req.type   = q->type;
1194         req.count  = count;
1195         req.memory = V4L2_MEMORY_MMAP;
1196         rc = videobuf_reqbufs(q, &req);
1197         if (rc < 0)
1198                 return rc;
1199
1200         mbuf->frames = req.count;
1201         mbuf->size   = 0;
1202         for (i = 0; i < mbuf->frames; i++) {
1203                 mbuf->offsets[i]  = q->bufs[i]->boff;
1204                 mbuf->size       += PAGE_ALIGN(q->bufs[i]->bsize);
1205         }
1206
1207         return 0;
1208 }
1209 EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
1210 #endif
1211