linux/drivers/media/common/videobuf2/videobuf2-v4l2.c
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   1/*
   2 * videobuf2-v4l2.c - V4L2 driver helper framework
   3 *
   4 * Copyright (C) 2010 Samsung Electronics
   5 *
   6 * Author: Pawel Osciak <pawel@osciak.com>
   7 *         Marek Szyprowski <m.szyprowski@samsung.com>
   8 *
   9 * The vb2_thread implementation was based on code from videobuf-dvb.c:
  10 *      (c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
  11 *
  12 * This program is free software; you can redistribute it and/or modify
  13 * it under the terms of the GNU General Public License as published by
  14 * the Free Software Foundation.
  15 */
  16
  17#include <linux/device.h>
  18#include <linux/err.h>
  19#include <linux/freezer.h>
  20#include <linux/kernel.h>
  21#include <linux/kthread.h>
  22#include <linux/mm.h>
  23#include <linux/module.h>
  24#include <linux/poll.h>
  25#include <linux/sched.h>
  26#include <linux/slab.h>
  27
  28#include <media/v4l2-common.h>
  29#include <media/v4l2-dev.h>
  30#include <media/v4l2-device.h>
  31#include <media/v4l2-event.h>
  32#include <media/v4l2-fh.h>
  33
  34#include <media/videobuf2-v4l2.h>
  35
  36static int debug;
  37module_param(debug, int, 0644);
  38
  39#define dprintk(q, level, fmt, arg...)                                        \
  40        do {                                                                  \
  41                if (debug >= level)                                           \
  42                        pr_info("vb2-v4l2: [%p] %s: " fmt,                    \
  43                                (q)->name, __func__, ## arg);                 \
  44        } while (0)
  45
  46/* Flags that are set by us */
  47#define V4L2_BUFFER_MASK_FLAGS  (V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
  48                                 V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \
  49                                 V4L2_BUF_FLAG_PREPARED | \
  50                                 V4L2_BUF_FLAG_IN_REQUEST | \
  51                                 V4L2_BUF_FLAG_REQUEST_FD | \
  52                                 V4L2_BUF_FLAG_TIMESTAMP_MASK)
  53/* Output buffer flags that should be passed on to the driver */
  54#define V4L2_BUFFER_OUT_FLAGS   (V4L2_BUF_FLAG_PFRAME | \
  55                                 V4L2_BUF_FLAG_BFRAME | \
  56                                 V4L2_BUF_FLAG_KEYFRAME | \
  57                                 V4L2_BUF_FLAG_TIMECODE | \
  58                                 V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF)
  59
  60/*
  61 * __verify_planes_array() - verify that the planes array passed in struct
  62 * v4l2_buffer from userspace can be safely used
  63 */
  64static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer *b)
  65{
  66        if (!V4L2_TYPE_IS_MULTIPLANAR(b->type))
  67                return 0;
  68
  69        /* Is memory for copying plane information present? */
  70        if (b->m.planes == NULL) {
  71                dprintk(vb->vb2_queue, 1,
  72                        "multi-planar buffer passed but planes array not provided\n");
  73                return -EINVAL;
  74        }
  75
  76        if (b->length < vb->num_planes || b->length > VB2_MAX_PLANES) {
  77                dprintk(vb->vb2_queue, 1,
  78                        "incorrect planes array length, expected %d, got %d\n",
  79                        vb->num_planes, b->length);
  80                return -EINVAL;
  81        }
  82
  83        return 0;
  84}
  85
  86static int __verify_planes_array_core(struct vb2_buffer *vb, const void *pb)
  87{
  88        return __verify_planes_array(vb, pb);
  89}
  90
  91/*
  92 * __verify_length() - Verify that the bytesused value for each plane fits in
  93 * the plane length and that the data offset doesn't exceed the bytesused value.
  94 */
  95static int __verify_length(struct vb2_buffer *vb, const struct v4l2_buffer *b)
  96{
  97        unsigned int length;
  98        unsigned int bytesused;
  99        unsigned int plane;
 100
 101        if (V4L2_TYPE_IS_CAPTURE(b->type))
 102                return 0;
 103
 104        if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
 105                for (plane = 0; plane < vb->num_planes; ++plane) {
 106                        length = (b->memory == VB2_MEMORY_USERPTR ||
 107                                  b->memory == VB2_MEMORY_DMABUF)
 108                               ? b->m.planes[plane].length
 109                                : vb->planes[plane].length;
 110                        bytesused = b->m.planes[plane].bytesused
 111                                  ? b->m.planes[plane].bytesused : length;
 112
 113                        if (b->m.planes[plane].bytesused > length)
 114                                return -EINVAL;
 115
 116                        if (b->m.planes[plane].data_offset > 0 &&
 117                            b->m.planes[plane].data_offset >= bytesused)
 118                                return -EINVAL;
 119                }
 120        } else {
 121                length = (b->memory == VB2_MEMORY_USERPTR ||
 122                          b->memory == VB2_MEMORY_DMABUF)
 123                        ? b->length : vb->planes[0].length;
 124
 125                if (b->bytesused > length)
 126                        return -EINVAL;
 127        }
 128
 129        return 0;
 130}
 131
 132/*
 133 * __init_vb2_v4l2_buffer() - initialize the vb2_v4l2_buffer struct
 134 */
 135static void __init_vb2_v4l2_buffer(struct vb2_buffer *vb)
 136{
 137        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 138
 139        vbuf->request_fd = -1;
 140}
 141
 142static void __copy_timestamp(struct vb2_buffer *vb, const void *pb)
 143{
 144        const struct v4l2_buffer *b = pb;
 145        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 146        struct vb2_queue *q = vb->vb2_queue;
 147
 148        if (q->is_output) {
 149                /*
 150                 * For output buffers copy the timestamp if needed,
 151                 * and the timecode field and flag if needed.
 152                 */
 153                if (q->copy_timestamp)
 154                        vb->timestamp = v4l2_buffer_get_timestamp(b);
 155                vbuf->flags |= b->flags & V4L2_BUF_FLAG_TIMECODE;
 156                if (b->flags & V4L2_BUF_FLAG_TIMECODE)
 157                        vbuf->timecode = b->timecode;
 158        }
 159};
 160
 161static void vb2_warn_zero_bytesused(struct vb2_buffer *vb)
 162{
 163        static bool check_once;
 164
 165        if (check_once)
 166                return;
 167
 168        check_once = true;
 169
 170        pr_warn("use of bytesused == 0 is deprecated and will be removed in the future,\n");
 171        if (vb->vb2_queue->allow_zero_bytesused)
 172                pr_warn("use VIDIOC_DECODER_CMD(V4L2_DEC_CMD_STOP) instead.\n");
 173        else
 174                pr_warn("use the actual size instead.\n");
 175}
 176
 177static int vb2_fill_vb2_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
 178{
 179        struct vb2_queue *q = vb->vb2_queue;
 180        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 181        struct vb2_plane *planes = vbuf->planes;
 182        unsigned int plane;
 183        int ret;
 184
 185        ret = __verify_length(vb, b);
 186        if (ret < 0) {
 187                dprintk(q, 1, "plane parameters verification failed: %d\n", ret);
 188                return ret;
 189        }
 190        if (b->field == V4L2_FIELD_ALTERNATE && q->is_output) {
 191                /*
 192                 * If the format's field is ALTERNATE, then the buffer's field
 193                 * should be either TOP or BOTTOM, not ALTERNATE since that
 194                 * makes no sense. The driver has to know whether the
 195                 * buffer represents a top or a bottom field in order to
 196                 * program any DMA correctly. Using ALTERNATE is wrong, since
 197                 * that just says that it is either a top or a bottom field,
 198                 * but not which of the two it is.
 199                 */
 200                dprintk(q, 1, "the field is incorrectly set to ALTERNATE for an output buffer\n");
 201                return -EINVAL;
 202        }
 203        vbuf->sequence = 0;
 204        vbuf->request_fd = -1;
 205        vbuf->is_held = false;
 206
 207        if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
 208                switch (b->memory) {
 209                case VB2_MEMORY_USERPTR:
 210                        for (plane = 0; plane < vb->num_planes; ++plane) {
 211                                planes[plane].m.userptr =
 212                                        b->m.planes[plane].m.userptr;
 213                                planes[plane].length =
 214                                        b->m.planes[plane].length;
 215                        }
 216                        break;
 217                case VB2_MEMORY_DMABUF:
 218                        for (plane = 0; plane < vb->num_planes; ++plane) {
 219                                planes[plane].m.fd =
 220                                        b->m.planes[plane].m.fd;
 221                                planes[plane].length =
 222                                        b->m.planes[plane].length;
 223                        }
 224                        break;
 225                default:
 226                        for (plane = 0; plane < vb->num_planes; ++plane) {
 227                                planes[plane].m.offset =
 228                                        vb->planes[plane].m.offset;
 229                                planes[plane].length =
 230                                        vb->planes[plane].length;
 231                        }
 232                        break;
 233                }
 234
 235                /* Fill in driver-provided information for OUTPUT types */
 236                if (V4L2_TYPE_IS_OUTPUT(b->type)) {
 237                        /*
 238                         * Will have to go up to b->length when API starts
 239                         * accepting variable number of planes.
 240                         *
 241                         * If bytesused == 0 for the output buffer, then fall
 242                         * back to the full buffer size. In that case
 243                         * userspace clearly never bothered to set it and
 244                         * it's a safe assumption that they really meant to
 245                         * use the full plane sizes.
 246                         *
 247                         * Some drivers, e.g. old codec drivers, use bytesused == 0
 248                         * as a way to indicate that streaming is finished.
 249                         * In that case, the driver should use the
 250                         * allow_zero_bytesused flag to keep old userspace
 251                         * applications working.
 252                         */
 253                        for (plane = 0; plane < vb->num_planes; ++plane) {
 254                                struct vb2_plane *pdst = &planes[plane];
 255                                struct v4l2_plane *psrc = &b->m.planes[plane];
 256
 257                                if (psrc->bytesused == 0)
 258                                        vb2_warn_zero_bytesused(vb);
 259
 260                                if (vb->vb2_queue->allow_zero_bytesused)
 261                                        pdst->bytesused = psrc->bytesused;
 262                                else
 263                                        pdst->bytesused = psrc->bytesused ?
 264                                                psrc->bytesused : pdst->length;
 265                                pdst->data_offset = psrc->data_offset;
 266                        }
 267                }
 268        } else {
 269                /*
 270                 * Single-planar buffers do not use planes array,
 271                 * so fill in relevant v4l2_buffer struct fields instead.
 272                 * In videobuf we use our internal V4l2_planes struct for
 273                 * single-planar buffers as well, for simplicity.
 274                 *
 275                 * If bytesused == 0 for the output buffer, then fall back
 276                 * to the full buffer size as that's a sensible default.
 277                 *
 278                 * Some drivers, e.g. old codec drivers, use bytesused == 0 as
 279                 * a way to indicate that streaming is finished. In that case,
 280                 * the driver should use the allow_zero_bytesused flag to keep
 281                 * old userspace applications working.
 282                 */
 283                switch (b->memory) {
 284                case VB2_MEMORY_USERPTR:
 285                        planes[0].m.userptr = b->m.userptr;
 286                        planes[0].length = b->length;
 287                        break;
 288                case VB2_MEMORY_DMABUF:
 289                        planes[0].m.fd = b->m.fd;
 290                        planes[0].length = b->length;
 291                        break;
 292                default:
 293                        planes[0].m.offset = vb->planes[0].m.offset;
 294                        planes[0].length = vb->planes[0].length;
 295                        break;
 296                }
 297
 298                planes[0].data_offset = 0;
 299                if (V4L2_TYPE_IS_OUTPUT(b->type)) {
 300                        if (b->bytesused == 0)
 301                                vb2_warn_zero_bytesused(vb);
 302
 303                        if (vb->vb2_queue->allow_zero_bytesused)
 304                                planes[0].bytesused = b->bytesused;
 305                        else
 306                                planes[0].bytesused = b->bytesused ?
 307                                        b->bytesused : planes[0].length;
 308                } else
 309                        planes[0].bytesused = 0;
 310
 311        }
 312
 313        /* Zero flags that we handle */
 314        vbuf->flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
 315        if (!vb->vb2_queue->copy_timestamp || V4L2_TYPE_IS_CAPTURE(b->type)) {
 316                /*
 317                 * Non-COPY timestamps and non-OUTPUT queues will get
 318                 * their timestamp and timestamp source flags from the
 319                 * queue.
 320                 */
 321                vbuf->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
 322        }
 323
 324        if (V4L2_TYPE_IS_OUTPUT(b->type)) {
 325                /*
 326                 * For output buffers mask out the timecode flag:
 327                 * this will be handled later in vb2_qbuf().
 328                 * The 'field' is valid metadata for this output buffer
 329                 * and so that needs to be copied here.
 330                 */
 331                vbuf->flags &= ~V4L2_BUF_FLAG_TIMECODE;
 332                vbuf->field = b->field;
 333                if (!(q->subsystem_flags & VB2_V4L2_FL_SUPPORTS_M2M_HOLD_CAPTURE_BUF))
 334                        vbuf->flags &= ~V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF;
 335        } else {
 336                /* Zero any output buffer flags as this is a capture buffer */
 337                vbuf->flags &= ~V4L2_BUFFER_OUT_FLAGS;
 338                /* Zero last flag, this is a signal from driver to userspace */
 339                vbuf->flags &= ~V4L2_BUF_FLAG_LAST;
 340        }
 341
 342        return 0;
 343}
 344
 345static void set_buffer_cache_hints(struct vb2_queue *q,
 346                                   struct vb2_buffer *vb,
 347                                   struct v4l2_buffer *b)
 348{
 349        /*
 350         * DMA exporter should take care of cache syncs, so we can avoid
 351         * explicit ->prepare()/->finish() syncs. For other ->memory types
 352         * we always need ->prepare() or/and ->finish() cache sync.
 353         */
 354        if (q->memory == VB2_MEMORY_DMABUF) {
 355                vb->need_cache_sync_on_finish = 0;
 356                vb->need_cache_sync_on_prepare = 0;
 357                return;
 358        }
 359
 360        /*
 361         * Cache sync/invalidation flags are set by default in order to
 362         * preserve existing behaviour for old apps/drivers.
 363         */
 364        vb->need_cache_sync_on_prepare = 1;
 365        vb->need_cache_sync_on_finish = 1;
 366
 367        if (!vb2_queue_allows_cache_hints(q)) {
 368                /*
 369                 * Clear buffer cache flags if queue does not support user
 370                 * space hints. That's to indicate to userspace that these
 371                 * flags won't work.
 372                 */
 373                b->flags &= ~V4L2_BUF_FLAG_NO_CACHE_INVALIDATE;
 374                b->flags &= ~V4L2_BUF_FLAG_NO_CACHE_CLEAN;
 375                return;
 376        }
 377
 378        /*
 379         * ->finish() cache sync can be avoided when queue direction is
 380         * TO_DEVICE.
 381         */
 382        if (q->dma_dir == DMA_TO_DEVICE)
 383                vb->need_cache_sync_on_finish = 0;
 384
 385        if (b->flags & V4L2_BUF_FLAG_NO_CACHE_INVALIDATE)
 386                vb->need_cache_sync_on_finish = 0;
 387
 388        if (b->flags & V4L2_BUF_FLAG_NO_CACHE_CLEAN)
 389                vb->need_cache_sync_on_prepare = 0;
 390}
 391
 392static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
 393                                    struct v4l2_buffer *b, bool is_prepare,
 394                                    struct media_request **p_req)
 395{
 396        const char *opname = is_prepare ? "prepare_buf" : "qbuf";
 397        struct media_request *req;
 398        struct vb2_v4l2_buffer *vbuf;
 399        struct vb2_buffer *vb;
 400        int ret;
 401
 402        if (b->type != q->type) {
 403                dprintk(q, 1, "%s: invalid buffer type\n", opname);
 404                return -EINVAL;
 405        }
 406
 407        if (b->index >= q->num_buffers) {
 408                dprintk(q, 1, "%s: buffer index out of range\n", opname);
 409                return -EINVAL;
 410        }
 411
 412        if (q->bufs[b->index] == NULL) {
 413                /* Should never happen */
 414                dprintk(q, 1, "%s: buffer is NULL\n", opname);
 415                return -EINVAL;
 416        }
 417
 418        if (b->memory != q->memory) {
 419                dprintk(q, 1, "%s: invalid memory type\n", opname);
 420                return -EINVAL;
 421        }
 422
 423        vb = q->bufs[b->index];
 424        vbuf = to_vb2_v4l2_buffer(vb);
 425        ret = __verify_planes_array(vb, b);
 426        if (ret)
 427                return ret;
 428
 429        if (!is_prepare && (b->flags & V4L2_BUF_FLAG_REQUEST_FD) &&
 430            vb->state != VB2_BUF_STATE_DEQUEUED) {
 431                dprintk(q, 1, "%s: buffer is not in dequeued state\n", opname);
 432                return -EINVAL;
 433        }
 434
 435        if (!vb->prepared) {
 436                set_buffer_cache_hints(q, vb, b);
 437                /* Copy relevant information provided by the userspace */
 438                memset(vbuf->planes, 0,
 439                       sizeof(vbuf->planes[0]) * vb->num_planes);
 440                ret = vb2_fill_vb2_v4l2_buffer(vb, b);
 441                if (ret)
 442                        return ret;
 443        }
 444
 445        if (is_prepare)
 446                return 0;
 447
 448        if (!(b->flags & V4L2_BUF_FLAG_REQUEST_FD)) {
 449                if (q->requires_requests) {
 450                        dprintk(q, 1, "%s: queue requires requests\n", opname);
 451                        return -EBADR;
 452                }
 453                if (q->uses_requests) {
 454                        dprintk(q, 1, "%s: queue uses requests\n", opname);
 455                        return -EBUSY;
 456                }
 457                return 0;
 458        } else if (!q->supports_requests) {
 459                dprintk(q, 1, "%s: queue does not support requests\n", opname);
 460                return -EBADR;
 461        } else if (q->uses_qbuf) {
 462                dprintk(q, 1, "%s: queue does not use requests\n", opname);
 463                return -EBUSY;
 464        }
 465
 466        /*
 467         * For proper locking when queueing a request you need to be able
 468         * to lock access to the vb2 queue, so check that there is a lock
 469         * that we can use. In addition p_req must be non-NULL.
 470         */
 471        if (WARN_ON(!q->lock || !p_req))
 472                return -EINVAL;
 473
 474        /*
 475         * Make sure this op is implemented by the driver. It's easy to forget
 476         * this callback, but is it important when canceling a buffer in a
 477         * queued request.
 478         */
 479        if (WARN_ON(!q->ops->buf_request_complete))
 480                return -EINVAL;
 481        /*
 482         * Make sure this op is implemented by the driver for the output queue.
 483         * It's easy to forget this callback, but is it important to correctly
 484         * validate the 'field' value at QBUF time.
 485         */
 486        if (WARN_ON((q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT ||
 487                     q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) &&
 488                    !q->ops->buf_out_validate))
 489                return -EINVAL;
 490
 491        if (b->request_fd < 0) {
 492                dprintk(q, 1, "%s: request_fd < 0\n", opname);
 493                return -EINVAL;
 494        }
 495
 496        req = media_request_get_by_fd(mdev, b->request_fd);
 497        if (IS_ERR(req)) {
 498                dprintk(q, 1, "%s: invalid request_fd\n", opname);
 499                return PTR_ERR(req);
 500        }
 501
 502        /*
 503         * Early sanity check. This is checked again when the buffer
 504         * is bound to the request in vb2_core_qbuf().
 505         */
 506        if (req->state != MEDIA_REQUEST_STATE_IDLE &&
 507            req->state != MEDIA_REQUEST_STATE_UPDATING) {
 508                dprintk(q, 1, "%s: request is not idle\n", opname);
 509                media_request_put(req);
 510                return -EBUSY;
 511        }
 512
 513        *p_req = req;
 514        vbuf->request_fd = b->request_fd;
 515
 516        return 0;
 517}
 518
 519/*
 520 * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
 521 * returned to userspace
 522 */
 523static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb)
 524{
 525        struct v4l2_buffer *b = pb;
 526        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 527        struct vb2_queue *q = vb->vb2_queue;
 528        unsigned int plane;
 529
 530        /* Copy back data such as timestamp, flags, etc. */
 531        b->index = vb->index;
 532        b->type = vb->type;
 533        b->memory = vb->memory;
 534        b->bytesused = 0;
 535
 536        b->flags = vbuf->flags;
 537        b->field = vbuf->field;
 538        v4l2_buffer_set_timestamp(b, vb->timestamp);
 539        b->timecode = vbuf->timecode;
 540        b->sequence = vbuf->sequence;
 541        b->reserved2 = 0;
 542        b->request_fd = 0;
 543
 544        if (q->is_multiplanar) {
 545                /*
 546                 * Fill in plane-related data if userspace provided an array
 547                 * for it. The caller has already verified memory and size.
 548                 */
 549                b->length = vb->num_planes;
 550                for (plane = 0; plane < vb->num_planes; ++plane) {
 551                        struct v4l2_plane *pdst = &b->m.planes[plane];
 552                        struct vb2_plane *psrc = &vb->planes[plane];
 553
 554                        pdst->bytesused = psrc->bytesused;
 555                        pdst->length = psrc->length;
 556                        if (q->memory == VB2_MEMORY_MMAP)
 557                                pdst->m.mem_offset = psrc->m.offset;
 558                        else if (q->memory == VB2_MEMORY_USERPTR)
 559                                pdst->m.userptr = psrc->m.userptr;
 560                        else if (q->memory == VB2_MEMORY_DMABUF)
 561                                pdst->m.fd = psrc->m.fd;
 562                        pdst->data_offset = psrc->data_offset;
 563                        memset(pdst->reserved, 0, sizeof(pdst->reserved));
 564                }
 565        } else {
 566                /*
 567                 * We use length and offset in v4l2_planes array even for
 568                 * single-planar buffers, but userspace does not.
 569                 */
 570                b->length = vb->planes[0].length;
 571                b->bytesused = vb->planes[0].bytesused;
 572                if (q->memory == VB2_MEMORY_MMAP)
 573                        b->m.offset = vb->planes[0].m.offset;
 574                else if (q->memory == VB2_MEMORY_USERPTR)
 575                        b->m.userptr = vb->planes[0].m.userptr;
 576                else if (q->memory == VB2_MEMORY_DMABUF)
 577                        b->m.fd = vb->planes[0].m.fd;
 578        }
 579
 580        /*
 581         * Clear any buffer state related flags.
 582         */
 583        b->flags &= ~V4L2_BUFFER_MASK_FLAGS;
 584        b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK;
 585        if (!q->copy_timestamp) {
 586                /*
 587                 * For non-COPY timestamps, drop timestamp source bits
 588                 * and obtain the timestamp source from the queue.
 589                 */
 590                b->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
 591                b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
 592        }
 593
 594        switch (vb->state) {
 595        case VB2_BUF_STATE_QUEUED:
 596        case VB2_BUF_STATE_ACTIVE:
 597                b->flags |= V4L2_BUF_FLAG_QUEUED;
 598                break;
 599        case VB2_BUF_STATE_IN_REQUEST:
 600                b->flags |= V4L2_BUF_FLAG_IN_REQUEST;
 601                break;
 602        case VB2_BUF_STATE_ERROR:
 603                b->flags |= V4L2_BUF_FLAG_ERROR;
 604                fallthrough;
 605        case VB2_BUF_STATE_DONE:
 606                b->flags |= V4L2_BUF_FLAG_DONE;
 607                break;
 608        case VB2_BUF_STATE_PREPARING:
 609        case VB2_BUF_STATE_DEQUEUED:
 610                /* nothing */
 611                break;
 612        }
 613
 614        if ((vb->state == VB2_BUF_STATE_DEQUEUED ||
 615             vb->state == VB2_BUF_STATE_IN_REQUEST) &&
 616            vb->synced && vb->prepared)
 617                b->flags |= V4L2_BUF_FLAG_PREPARED;
 618
 619        if (vb2_buffer_in_use(q, vb))
 620                b->flags |= V4L2_BUF_FLAG_MAPPED;
 621        if (vbuf->request_fd >= 0) {
 622                b->flags |= V4L2_BUF_FLAG_REQUEST_FD;
 623                b->request_fd = vbuf->request_fd;
 624        }
 625}
 626
 627/*
 628 * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
 629 * v4l2_buffer by the userspace. It also verifies that struct
 630 * v4l2_buffer has a valid number of planes.
 631 */
 632static int __fill_vb2_buffer(struct vb2_buffer *vb, struct vb2_plane *planes)
 633{
 634        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 635        unsigned int plane;
 636
 637        if (!vb->vb2_queue->copy_timestamp)
 638                vb->timestamp = 0;
 639
 640        for (plane = 0; plane < vb->num_planes; ++plane) {
 641                if (vb->vb2_queue->memory != VB2_MEMORY_MMAP) {
 642                        planes[plane].m = vbuf->planes[plane].m;
 643                        planes[plane].length = vbuf->planes[plane].length;
 644                }
 645                planes[plane].bytesused = vbuf->planes[plane].bytesused;
 646                planes[plane].data_offset = vbuf->planes[plane].data_offset;
 647        }
 648        return 0;
 649}
 650
 651static const struct vb2_buf_ops v4l2_buf_ops = {
 652        .verify_planes_array    = __verify_planes_array_core,
 653        .init_buffer            = __init_vb2_v4l2_buffer,
 654        .fill_user_buffer       = __fill_v4l2_buffer,
 655        .fill_vb2_buffer        = __fill_vb2_buffer,
 656        .copy_timestamp         = __copy_timestamp,
 657};
 658
 659int vb2_find_timestamp(const struct vb2_queue *q, u64 timestamp,
 660                       unsigned int start_idx)
 661{
 662        unsigned int i;
 663
 664        for (i = start_idx; i < q->num_buffers; i++)
 665                if (q->bufs[i]->copied_timestamp &&
 666                    q->bufs[i]->timestamp == timestamp)
 667                        return i;
 668        return -1;
 669}
 670EXPORT_SYMBOL_GPL(vb2_find_timestamp);
 671
 672/*
 673 * vb2_querybuf() - query video buffer information
 674 * @q:          videobuf queue
 675 * @b:          buffer struct passed from userspace to vidioc_querybuf handler
 676 *              in driver
 677 *
 678 * Should be called from vidioc_querybuf ioctl handler in driver.
 679 * This function will verify the passed v4l2_buffer structure and fill the
 680 * relevant information for the userspace.
 681 *
 682 * The return values from this function are intended to be directly returned
 683 * from vidioc_querybuf handler in driver.
 684 */
 685int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
 686{
 687        struct vb2_buffer *vb;
 688        int ret;
 689
 690        if (b->type != q->type) {
 691                dprintk(q, 1, "wrong buffer type\n");
 692                return -EINVAL;
 693        }
 694
 695        if (b->index >= q->num_buffers) {
 696                dprintk(q, 1, "buffer index out of range\n");
 697                return -EINVAL;
 698        }
 699        vb = q->bufs[b->index];
 700        ret = __verify_planes_array(vb, b);
 701        if (!ret)
 702                vb2_core_querybuf(q, b->index, b);
 703        return ret;
 704}
 705EXPORT_SYMBOL(vb2_querybuf);
 706
 707static void fill_buf_caps(struct vb2_queue *q, u32 *caps)
 708{
 709        *caps = V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS;
 710        if (q->io_modes & VB2_MMAP)
 711                *caps |= V4L2_BUF_CAP_SUPPORTS_MMAP;
 712        if (q->io_modes & VB2_USERPTR)
 713                *caps |= V4L2_BUF_CAP_SUPPORTS_USERPTR;
 714        if (q->io_modes & VB2_DMABUF)
 715                *caps |= V4L2_BUF_CAP_SUPPORTS_DMABUF;
 716        if (q->subsystem_flags & VB2_V4L2_FL_SUPPORTS_M2M_HOLD_CAPTURE_BUF)
 717                *caps |= V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF;
 718        if (q->allow_cache_hints && q->io_modes & VB2_MMAP)
 719                *caps |= V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS;
 720#ifdef CONFIG_MEDIA_CONTROLLER_REQUEST_API
 721        if (q->supports_requests)
 722                *caps |= V4L2_BUF_CAP_SUPPORTS_REQUESTS;
 723#endif
 724}
 725
 726int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
 727{
 728        int ret = vb2_verify_memory_type(q, req->memory, req->type);
 729
 730        fill_buf_caps(q, &req->capabilities);
 731        return ret ? ret : vb2_core_reqbufs(q, req->memory, &req->count);
 732}
 733EXPORT_SYMBOL_GPL(vb2_reqbufs);
 734
 735int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
 736                    struct v4l2_buffer *b)
 737{
 738        int ret;
 739
 740        if (vb2_fileio_is_active(q)) {
 741                dprintk(q, 1, "file io in progress\n");
 742                return -EBUSY;
 743        }
 744
 745        if (b->flags & V4L2_BUF_FLAG_REQUEST_FD)
 746                return -EINVAL;
 747
 748        ret = vb2_queue_or_prepare_buf(q, mdev, b, true, NULL);
 749
 750        return ret ? ret : vb2_core_prepare_buf(q, b->index, b);
 751}
 752EXPORT_SYMBOL_GPL(vb2_prepare_buf);
 753
 754int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
 755{
 756        unsigned requested_planes = 1;
 757        unsigned requested_sizes[VIDEO_MAX_PLANES];
 758        struct v4l2_format *f = &create->format;
 759        int ret = vb2_verify_memory_type(q, create->memory, f->type);
 760        unsigned i;
 761
 762        fill_buf_caps(q, &create->capabilities);
 763        create->index = q->num_buffers;
 764        if (create->count == 0)
 765                return ret != -EBUSY ? ret : 0;
 766
 767        switch (f->type) {
 768        case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
 769        case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE:
 770                requested_planes = f->fmt.pix_mp.num_planes;
 771                if (requested_planes == 0 ||
 772                    requested_planes > VIDEO_MAX_PLANES)
 773                        return -EINVAL;
 774                for (i = 0; i < requested_planes; i++)
 775                        requested_sizes[i] =
 776                                f->fmt.pix_mp.plane_fmt[i].sizeimage;
 777                break;
 778        case V4L2_BUF_TYPE_VIDEO_CAPTURE:
 779        case V4L2_BUF_TYPE_VIDEO_OUTPUT:
 780                requested_sizes[0] = f->fmt.pix.sizeimage;
 781                break;
 782        case V4L2_BUF_TYPE_VBI_CAPTURE:
 783        case V4L2_BUF_TYPE_VBI_OUTPUT:
 784                requested_sizes[0] = f->fmt.vbi.samples_per_line *
 785                        (f->fmt.vbi.count[0] + f->fmt.vbi.count[1]);
 786                break;
 787        case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE:
 788        case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
 789                requested_sizes[0] = f->fmt.sliced.io_size;
 790                break;
 791        case V4L2_BUF_TYPE_SDR_CAPTURE:
 792        case V4L2_BUF_TYPE_SDR_OUTPUT:
 793                requested_sizes[0] = f->fmt.sdr.buffersize;
 794                break;
 795        case V4L2_BUF_TYPE_META_CAPTURE:
 796        case V4L2_BUF_TYPE_META_OUTPUT:
 797                requested_sizes[0] = f->fmt.meta.buffersize;
 798                break;
 799        default:
 800                return -EINVAL;
 801        }
 802        for (i = 0; i < requested_planes; i++)
 803                if (requested_sizes[i] == 0)
 804                        return -EINVAL;
 805        return ret ? ret : vb2_core_create_bufs(q, create->memory,
 806                                                &create->count,
 807                                                requested_planes,
 808                                                requested_sizes);
 809}
 810EXPORT_SYMBOL_GPL(vb2_create_bufs);
 811
 812int vb2_qbuf(struct vb2_queue *q, struct media_device *mdev,
 813             struct v4l2_buffer *b)
 814{
 815        struct media_request *req = NULL;
 816        int ret;
 817
 818        if (vb2_fileio_is_active(q)) {
 819                dprintk(q, 1, "file io in progress\n");
 820                return -EBUSY;
 821        }
 822
 823        ret = vb2_queue_or_prepare_buf(q, mdev, b, false, &req);
 824        if (ret)
 825                return ret;
 826        ret = vb2_core_qbuf(q, b->index, b, req);
 827        if (req)
 828                media_request_put(req);
 829        return ret;
 830}
 831EXPORT_SYMBOL_GPL(vb2_qbuf);
 832
 833int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
 834{
 835        int ret;
 836
 837        if (vb2_fileio_is_active(q)) {
 838                dprintk(q, 1, "file io in progress\n");
 839                return -EBUSY;
 840        }
 841
 842        if (b->type != q->type) {
 843                dprintk(q, 1, "invalid buffer type\n");
 844                return -EINVAL;
 845        }
 846
 847        ret = vb2_core_dqbuf(q, NULL, b, nonblocking);
 848
 849        if (!q->is_output &&
 850            b->flags & V4L2_BUF_FLAG_DONE &&
 851            b->flags & V4L2_BUF_FLAG_LAST)
 852                q->last_buffer_dequeued = true;
 853
 854        /*
 855         *  After calling the VIDIOC_DQBUF V4L2_BUF_FLAG_DONE must be
 856         *  cleared.
 857         */
 858        b->flags &= ~V4L2_BUF_FLAG_DONE;
 859
 860        return ret;
 861}
 862EXPORT_SYMBOL_GPL(vb2_dqbuf);
 863
 864int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
 865{
 866        if (vb2_fileio_is_active(q)) {
 867                dprintk(q, 1, "file io in progress\n");
 868                return -EBUSY;
 869        }
 870        return vb2_core_streamon(q, type);
 871}
 872EXPORT_SYMBOL_GPL(vb2_streamon);
 873
 874int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
 875{
 876        if (vb2_fileio_is_active(q)) {
 877                dprintk(q, 1, "file io in progress\n");
 878                return -EBUSY;
 879        }
 880        return vb2_core_streamoff(q, type);
 881}
 882EXPORT_SYMBOL_GPL(vb2_streamoff);
 883
 884int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)
 885{
 886        return vb2_core_expbuf(q, &eb->fd, eb->type, eb->index,
 887                                eb->plane, eb->flags);
 888}
 889EXPORT_SYMBOL_GPL(vb2_expbuf);
 890
 891int vb2_queue_init_name(struct vb2_queue *q, const char *name)
 892{
 893        /*
 894         * Sanity check
 895         */
 896        if (WARN_ON(!q)                   ||
 897            WARN_ON(q->timestamp_flags &
 898                    ~(V4L2_BUF_FLAG_TIMESTAMP_MASK |
 899                      V4L2_BUF_FLAG_TSTAMP_SRC_MASK)))
 900                return -EINVAL;
 901
 902        /* Warn that the driver should choose an appropriate timestamp type */
 903        WARN_ON((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
 904                V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN);
 905
 906        /* Warn that vb2_memory should match with v4l2_memory */
 907        if (WARN_ON(VB2_MEMORY_MMAP != (int)V4L2_MEMORY_MMAP)
 908                || WARN_ON(VB2_MEMORY_USERPTR != (int)V4L2_MEMORY_USERPTR)
 909                || WARN_ON(VB2_MEMORY_DMABUF != (int)V4L2_MEMORY_DMABUF))
 910                return -EINVAL;
 911
 912        if (q->buf_struct_size == 0)
 913                q->buf_struct_size = sizeof(struct vb2_v4l2_buffer);
 914
 915        q->buf_ops = &v4l2_buf_ops;
 916        q->is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(q->type);
 917        q->is_output = V4L2_TYPE_IS_OUTPUT(q->type);
 918        q->copy_timestamp = (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK)
 919                        == V4L2_BUF_FLAG_TIMESTAMP_COPY;
 920        /*
 921         * For compatibility with vb1: if QBUF hasn't been called yet, then
 922         * return EPOLLERR as well. This only affects capture queues, output
 923         * queues will always initialize waiting_for_buffers to false.
 924         */
 925        q->quirk_poll_must_check_waiting_for_buffers = true;
 926
 927        if (name)
 928                strscpy(q->name, name, sizeof(q->name));
 929        else
 930                q->name[0] = '\0';
 931
 932        return vb2_core_queue_init(q);
 933}
 934EXPORT_SYMBOL_GPL(vb2_queue_init_name);
 935
 936int vb2_queue_init(struct vb2_queue *q)
 937{
 938        return vb2_queue_init_name(q, NULL);
 939}
 940EXPORT_SYMBOL_GPL(vb2_queue_init);
 941
 942void vb2_queue_release(struct vb2_queue *q)
 943{
 944        vb2_core_queue_release(q);
 945}
 946EXPORT_SYMBOL_GPL(vb2_queue_release);
 947
 948__poll_t vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
 949{
 950        struct video_device *vfd = video_devdata(file);
 951        __poll_t res;
 952
 953        res = vb2_core_poll(q, file, wait);
 954
 955        if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
 956                struct v4l2_fh *fh = file->private_data;
 957
 958                poll_wait(file, &fh->wait, wait);
 959                if (v4l2_event_pending(fh))
 960                        res |= EPOLLPRI;
 961        }
 962
 963        return res;
 964}
 965EXPORT_SYMBOL_GPL(vb2_poll);
 966
 967/*
 968 * The following functions are not part of the vb2 core API, but are helper
 969 * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
 970 * and struct vb2_ops.
 971 * They contain boilerplate code that most if not all drivers have to do
 972 * and so they simplify the driver code.
 973 */
 974
 975/* The queue is busy if there is a owner and you are not that owner. */
 976static inline bool vb2_queue_is_busy(struct video_device *vdev, struct file *file)
 977{
 978        return vdev->queue->owner && vdev->queue->owner != file->private_data;
 979}
 980
 981/* vb2 ioctl helpers */
 982
 983int vb2_ioctl_reqbufs(struct file *file, void *priv,
 984                          struct v4l2_requestbuffers *p)
 985{
 986        struct video_device *vdev = video_devdata(file);
 987        int res = vb2_verify_memory_type(vdev->queue, p->memory, p->type);
 988
 989        fill_buf_caps(vdev->queue, &p->capabilities);
 990        if (res)
 991                return res;
 992        if (vb2_queue_is_busy(vdev, file))
 993                return -EBUSY;
 994        res = vb2_core_reqbufs(vdev->queue, p->memory, &p->count);
 995        /* If count == 0, then the owner has released all buffers and he
 996           is no longer owner of the queue. Otherwise we have a new owner. */
 997        if (res == 0)
 998                vdev->queue->owner = p->count ? file->private_data : NULL;
 999        return res;
1000}
1001EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs);
1002
1003int vb2_ioctl_create_bufs(struct file *file, void *priv,
1004                          struct v4l2_create_buffers *p)
1005{
1006        struct video_device *vdev = video_devdata(file);
1007        int res = vb2_verify_memory_type(vdev->queue, p->memory,
1008                        p->format.type);
1009
1010        p->index = vdev->queue->num_buffers;
1011        fill_buf_caps(vdev->queue, &p->capabilities);
1012        /*
1013         * If count == 0, then just check if memory and type are valid.
1014         * Any -EBUSY result from vb2_verify_memory_type can be mapped to 0.
1015         */
1016        if (p->count == 0)
1017                return res != -EBUSY ? res : 0;
1018        if (res)
1019                return res;
1020        if (vb2_queue_is_busy(vdev, file))
1021                return -EBUSY;
1022
1023        res = vb2_create_bufs(vdev->queue, p);
1024        if (res == 0)
1025                vdev->queue->owner = file->private_data;
1026        return res;
1027}
1028EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs);
1029
1030int vb2_ioctl_prepare_buf(struct file *file, void *priv,
1031                          struct v4l2_buffer *p)
1032{
1033        struct video_device *vdev = video_devdata(file);
1034
1035        if (vb2_queue_is_busy(vdev, file))
1036                return -EBUSY;
1037        return vb2_prepare_buf(vdev->queue, vdev->v4l2_dev->mdev, p);
1038}
1039EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf);
1040
1041int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
1042{
1043        struct video_device *vdev = video_devdata(file);
1044
1045        /* No need to call vb2_queue_is_busy(), anyone can query buffers. */
1046        return vb2_querybuf(vdev->queue, p);
1047}
1048EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf);
1049
1050int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
1051{
1052        struct video_device *vdev = video_devdata(file);
1053
1054        if (vb2_queue_is_busy(vdev, file))
1055                return -EBUSY;
1056        return vb2_qbuf(vdev->queue, vdev->v4l2_dev->mdev, p);
1057}
1058EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf);
1059
1060int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
1061{
1062        struct video_device *vdev = video_devdata(file);
1063
1064        if (vb2_queue_is_busy(vdev, file))
1065                return -EBUSY;
1066        return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK);
1067}
1068EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf);
1069
1070int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
1071{
1072        struct video_device *vdev = video_devdata(file);
1073
1074        if (vb2_queue_is_busy(vdev, file))
1075                return -EBUSY;
1076        return vb2_streamon(vdev->queue, i);
1077}
1078EXPORT_SYMBOL_GPL(vb2_ioctl_streamon);
1079
1080int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
1081{
1082        struct video_device *vdev = video_devdata(file);
1083
1084        if (vb2_queue_is_busy(vdev, file))
1085                return -EBUSY;
1086        return vb2_streamoff(vdev->queue, i);
1087}
1088EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff);
1089
1090int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p)
1091{
1092        struct video_device *vdev = video_devdata(file);
1093
1094        if (vb2_queue_is_busy(vdev, file))
1095                return -EBUSY;
1096        return vb2_expbuf(vdev->queue, p);
1097}
1098EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf);
1099
1100/* v4l2_file_operations helpers */
1101
1102int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma)
1103{
1104        struct video_device *vdev = video_devdata(file);
1105
1106        return vb2_mmap(vdev->queue, vma);
1107}
1108EXPORT_SYMBOL_GPL(vb2_fop_mmap);
1109
1110int _vb2_fop_release(struct file *file, struct mutex *lock)
1111{
1112        struct video_device *vdev = video_devdata(file);
1113
1114        if (lock)
1115                mutex_lock(lock);
1116        if (file->private_data == vdev->queue->owner) {
1117                vb2_queue_release(vdev->queue);
1118                vdev->queue->owner = NULL;
1119        }
1120        if (lock)
1121                mutex_unlock(lock);
1122        return v4l2_fh_release(file);
1123}
1124EXPORT_SYMBOL_GPL(_vb2_fop_release);
1125
1126int vb2_fop_release(struct file *file)
1127{
1128        struct video_device *vdev = video_devdata(file);
1129        struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
1130
1131        return _vb2_fop_release(file, lock);
1132}
1133EXPORT_SYMBOL_GPL(vb2_fop_release);
1134
1135ssize_t vb2_fop_write(struct file *file, const char __user *buf,
1136                size_t count, loff_t *ppos)
1137{
1138        struct video_device *vdev = video_devdata(file);
1139        struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
1140        int err = -EBUSY;
1141
1142        if (!(vdev->queue->io_modes & VB2_WRITE))
1143                return -EINVAL;
1144        if (lock && mutex_lock_interruptible(lock))
1145                return -ERESTARTSYS;
1146        if (vb2_queue_is_busy(vdev, file))
1147                goto exit;
1148        err = vb2_write(vdev->queue, buf, count, ppos,
1149                       file->f_flags & O_NONBLOCK);
1150        if (vdev->queue->fileio)
1151                vdev->queue->owner = file->private_data;
1152exit:
1153        if (lock)
1154                mutex_unlock(lock);
1155        return err;
1156}
1157EXPORT_SYMBOL_GPL(vb2_fop_write);
1158
1159ssize_t vb2_fop_read(struct file *file, char __user *buf,
1160                size_t count, loff_t *ppos)
1161{
1162        struct video_device *vdev = video_devdata(file);
1163        struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
1164        int err = -EBUSY;
1165
1166        if (!(vdev->queue->io_modes & VB2_READ))
1167                return -EINVAL;
1168        if (lock && mutex_lock_interruptible(lock))
1169                return -ERESTARTSYS;
1170        if (vb2_queue_is_busy(vdev, file))
1171                goto exit;
1172        err = vb2_read(vdev->queue, buf, count, ppos,
1173                       file->f_flags & O_NONBLOCK);
1174        if (vdev->queue->fileio)
1175                vdev->queue->owner = file->private_data;
1176exit:
1177        if (lock)
1178                mutex_unlock(lock);
1179        return err;
1180}
1181EXPORT_SYMBOL_GPL(vb2_fop_read);
1182
1183__poll_t vb2_fop_poll(struct file *file, poll_table *wait)
1184{
1185        struct video_device *vdev = video_devdata(file);
1186        struct vb2_queue *q = vdev->queue;
1187        struct mutex *lock = q->lock ? q->lock : vdev->lock;
1188        __poll_t res;
1189        void *fileio;
1190
1191        /*
1192         * If this helper doesn't know how to lock, then you shouldn't be using
1193         * it but you should write your own.
1194         */
1195        WARN_ON(!lock);
1196
1197        if (lock && mutex_lock_interruptible(lock))
1198                return EPOLLERR;
1199
1200        fileio = q->fileio;
1201
1202        res = vb2_poll(vdev->queue, file, wait);
1203
1204        /* If fileio was started, then we have a new queue owner. */
1205        if (!fileio && q->fileio)
1206                q->owner = file->private_data;
1207        if (lock)
1208                mutex_unlock(lock);
1209        return res;
1210}
1211EXPORT_SYMBOL_GPL(vb2_fop_poll);
1212
1213#ifndef CONFIG_MMU
1214unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
1215                unsigned long len, unsigned long pgoff, unsigned long flags)
1216{
1217        struct video_device *vdev = video_devdata(file);
1218
1219        return vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags);
1220}
1221EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area);
1222#endif
1223
1224void vb2_video_unregister_device(struct video_device *vdev)
1225{
1226        /* Check if vdev was ever registered at all */
1227        if (!vdev || !video_is_registered(vdev))
1228                return;
1229
1230        /*
1231         * Calling this function only makes sense if vdev->queue is set.
1232         * If it is NULL, then just call video_unregister_device() instead.
1233         */
1234        WARN_ON(!vdev->queue);
1235
1236        /*
1237         * Take a reference to the device since video_unregister_device()
1238         * calls device_unregister(), but we don't want that to release
1239         * the device since we want to clean up the queue first.
1240         */
1241        get_device(&vdev->dev);
1242        video_unregister_device(vdev);
1243        if (vdev->queue && vdev->queue->owner) {
1244                struct mutex *lock = vdev->queue->lock ?
1245                        vdev->queue->lock : vdev->lock;
1246
1247                if (lock)
1248                        mutex_lock(lock);
1249                vb2_queue_release(vdev->queue);
1250                vdev->queue->owner = NULL;
1251                if (lock)
1252                        mutex_unlock(lock);
1253        }
1254        /*
1255         * Now we put the device, and in most cases this will release
1256         * everything.
1257         */
1258        put_device(&vdev->dev);
1259}
1260EXPORT_SYMBOL_GPL(vb2_video_unregister_device);
1261
1262/* vb2_ops helpers. Only use if vq->lock is non-NULL. */
1263
1264void vb2_ops_wait_prepare(struct vb2_queue *vq)
1265{
1266        mutex_unlock(vq->lock);
1267}
1268EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare);
1269
1270void vb2_ops_wait_finish(struct vb2_queue *vq)
1271{
1272        mutex_lock(vq->lock);
1273}
1274EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);
1275
1276/*
1277 * Note that this function is called during validation time and
1278 * thus the req_queue_mutex is held to ensure no request objects
1279 * can be added or deleted while validating. So there is no need
1280 * to protect the objects list.
1281 */
1282int vb2_request_validate(struct media_request *req)
1283{
1284        struct media_request_object *obj;
1285        int ret = 0;
1286
1287        if (!vb2_request_buffer_cnt(req))
1288                return -ENOENT;
1289
1290        list_for_each_entry(obj, &req->objects, list) {
1291                if (!obj->ops->prepare)
1292                        continue;
1293
1294                ret = obj->ops->prepare(obj);
1295                if (ret)
1296                        break;
1297        }
1298
1299        if (ret) {
1300                list_for_each_entry_continue_reverse(obj, &req->objects, list)
1301                        if (obj->ops->unprepare)
1302                                obj->ops->unprepare(obj);
1303                return ret;
1304        }
1305        return 0;
1306}
1307EXPORT_SYMBOL_GPL(vb2_request_validate);
1308
1309void vb2_request_queue(struct media_request *req)
1310{
1311        struct media_request_object *obj, *obj_safe;
1312
1313        /*
1314         * Queue all objects. Note that buffer objects are at the end of the
1315         * objects list, after all other object types. Once buffer objects
1316         * are queued, the driver might delete them immediately (if the driver
1317         * processes the buffer at once), so we have to use
1318         * list_for_each_entry_safe() to handle the case where the object we
1319         * queue is deleted.
1320         */
1321        list_for_each_entry_safe(obj, obj_safe, &req->objects, list)
1322                if (obj->ops->queue)
1323                        obj->ops->queue(obj);
1324}
1325EXPORT_SYMBOL_GPL(vb2_request_queue);
1326
1327MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
1328MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
1329MODULE_LICENSE("GPL");
1330