drivers/media/usb/uvc/uvc_queue.c

   1 /*
   2  *      uvc_queue.c  --  USB Video Class driver - Buffers management
   3  *
   4  *      Copyright (C) 2005-2010
   5  *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
   6  *
   7  *      This program is free software; you can redistribute it and/or modify
   8  *      it under the terms of the GNU General Public License as published by
   9  *      the Free Software Foundation; either version 2 of the License, or
  10  *      (at your option) any later version.
  11  *
  12  */
  13
  14 #include <linux/atomic.h>
  15 #include <linux/kernel.h>
  16 #include <linux/mm.h>
  17 #include <linux/list.h>
  18 #include <linux/module.h>
  19 #include <linux/usb.h>
  20 #include <linux/videodev2.h>
  21 #include <linux/vmalloc.h>
  22 #include <linux/wait.h>
  23 #include <media/videobuf2-v4l2.h>
  24 #include <media/videobuf2-vmalloc.h>
  25
  26 #include "uvcvideo.h"
  27
  28 /* ------------------------------------------------------------------------
  29  * Video buffers queue management.
  30  *
  31  * Video queues is initialized by uvc_queue_init(). The function performs
  32  * basic initialization of the uvc_video_queue struct and never fails.
  33  *
  34  * Video buffers are managed by videobuf2. The driver uses a mutex to protect
  35  * the videobuf2 queue operations by serializing calls to videobuf2 and a
  36  * spinlock to protect the IRQ queue that holds the buffers to be processed by
  37  * the driver.
  38  */
  39
  40 static inline struct uvc_streaming *
  41 uvc_queue_to_stream(struct uvc_video_queue *queue)
  42 {
  43         return container_of(queue, struct uvc_streaming, queue);
  44 }
  45
  46 static inline struct uvc_buffer *uvc_vbuf_to_buffer(struct vb2_v4l2_buffer *buf)
  47 {
  48         return container_of(buf, struct uvc_buffer, buf);
  49 }
  50
  51 /*
  52  * Return all queued buffers to videobuf2 in the requested state.
  53  *
  54  * This function must be called with the queue spinlock held.
  55  */
  56 static void uvc_queue_return_buffers(struct uvc_video_queue *queue,
  57                                enum uvc_buffer_state state)
  58 {
  59         enum vb2_buffer_state vb2_state = state == UVC_BUF_STATE_ERROR
  60                                         ? VB2_BUF_STATE_ERROR
  61                                         : VB2_BUF_STATE_QUEUED;
  62
  63         while (!list_empty(&queue->irqqueue)) {
  64                 struct uvc_buffer *buf = list_first_entry(&queue->irqqueue,
  65                                                           struct uvc_buffer,
  66                                                           queue);
  67                 list_del(&buf->queue);
  68                 buf->state = state;
  69                 vb2_buffer_done(&buf->buf.vb2_buf, vb2_state);
  70         }
  71 }
  72
  73 /* -----------------------------------------------------------------------------
  74  * videobuf2 queue operations
  75  */
  76
  77 static int uvc_queue_setup(struct vb2_queue *vq,
  78                            unsigned int *nbuffers, unsigned int *nplanes,
  79                            unsigned int sizes[], struct device *alloc_devs[])
  80 {
  81         struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
  82         struct uvc_streaming *stream;
  83         unsigned int size;
  84
  85         switch (vq->type) {
  86         case V4L2_BUF_TYPE_META_CAPTURE:
  87                 size = UVC_METATADA_BUF_SIZE;
  88                 break;
  89
  90         default:
  91                 stream = uvc_queue_to_stream(queue);
  92                 size = stream->ctrl.dwMaxVideoFrameSize;
  93                 break;
  94         }
  95
  96         /*
  97          * When called with plane sizes, validate them. The driver supports
  98          * single planar formats only, and requires buffers to be large enough
  99          * to store a complete frame.
 100          */
 101         if (*nplanes)
 102                 return *nplanes != 1 || sizes[0] < size ? -EINVAL : 0;
 103
 104         *nplanes = 1;
 105         sizes[0] = size;
 106         return 0;
 107 }
 108
 109 static int uvc_buffer_prepare(struct vb2_buffer *vb)
 110 {
 111         struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 112         struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
 113         struct uvc_buffer *buf = uvc_vbuf_to_buffer(vbuf);
 114
 115         if (vb->type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
 116             vb2_get_plane_payload(vb, 0) > vb2_plane_size(vb, 0)) {
 117                 uvc_trace(UVC_TRACE_CAPTURE, "[E] Bytes used out of bounds.\n");
 118                 return -EINVAL;
 119         }
 120
 121         if (unlikely(queue->flags & UVC_QUEUE_DISCONNECTED))
 122                 return -ENODEV;
 123
 124         buf->state = UVC_BUF_STATE_QUEUED;
 125         buf->error = 0;
 126         buf->mem = vb2_plane_vaddr(vb, 0);
 127         buf->length = vb2_plane_size(vb, 0);
 128         if (vb->type != V4L2_BUF_TYPE_VIDEO_OUTPUT)
 129                 buf->bytesused = 0;
 130         else
 131                 buf->bytesused = vb2_get_plane_payload(vb, 0);
 132
 133         return 0;
 134 }
 135
 136 static void uvc_buffer_queue(struct vb2_buffer *vb)
 137 {
 138         struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 139         struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
 140         struct uvc_buffer *buf = uvc_vbuf_to_buffer(vbuf);
 141         unsigned long flags;
 142
 143         spin_lock_irqsave(&queue->irqlock, flags);
 144         if (likely(!(queue->flags & UVC_QUEUE_DISCONNECTED))) {
 145                 list_add_tail(&buf->queue, &queue->irqqueue);
 146         } else {
 147                 /* If the device is disconnected return the buffer to userspace
 148                  * directly. The next QBUF call will fail with -ENODEV.
 149                  */
 150                 buf->state = UVC_BUF_STATE_ERROR;
 151                 vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
 152         }
 153
 154         spin_unlock_irqrestore(&queue->irqlock, flags);
 155 }
 156
 157 static void uvc_buffer_finish(struct vb2_buffer *vb)
 158 {
 159         struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 160         struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
 161         struct uvc_streaming *stream = uvc_queue_to_stream(queue);
 162         struct uvc_buffer *buf = uvc_vbuf_to_buffer(vbuf);
 163
 164         if (vb->state == VB2_BUF_STATE_DONE)
 165                 uvc_video_clock_update(stream, vbuf, buf);
 166 }
 167
 168 static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count)
 169 {
 170         struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
 171         struct uvc_streaming *stream = uvc_queue_to_stream(queue);
 172         unsigned long flags;
 173         int ret;
 174
 175         queue->buf_used = 0;
 176
 177         ret = uvc_video_enable(stream, 1);
 178         if (ret == 0)
 179                 return 0;
 180
 181         spin_lock_irqsave(&queue->irqlock, flags);
 182         uvc_queue_return_buffers(queue, UVC_BUF_STATE_QUEUED);
 183         spin_unlock_irqrestore(&queue->irqlock, flags);
 184
 185         return ret;
 186 }
 187
 188 static void uvc_stop_streaming(struct vb2_queue *vq)
 189 {
 190         struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
 191         unsigned long flags;
 192
 193         if (vq->type != V4L2_BUF_TYPE_META_CAPTURE)
 194                 uvc_video_enable(uvc_queue_to_stream(queue), 0);
 195
 196         spin_lock_irqsave(&queue->irqlock, flags);
 197         uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
 198         spin_unlock_irqrestore(&queue->irqlock, flags);
 199 }
 200
 201 static const struct vb2_ops uvc_queue_qops = {
 202         .queue_setup = uvc_queue_setup,
 203         .buf_prepare = uvc_buffer_prepare,
 204         .buf_queue = uvc_buffer_queue,
 205         .buf_finish = uvc_buffer_finish,
 206         .wait_prepare = vb2_ops_wait_prepare,
 207         .wait_finish = vb2_ops_wait_finish,
 208         .start_streaming = uvc_start_streaming,
 209         .stop_streaming = uvc_stop_streaming,
 210 };
 211
 212 static const struct vb2_ops uvc_meta_queue_qops = {
 213         .queue_setup = uvc_queue_setup,
 214         .buf_prepare = uvc_buffer_prepare,
 215         .buf_queue = uvc_buffer_queue,
 216         .wait_prepare = vb2_ops_wait_prepare,
 217         .wait_finish = vb2_ops_wait_finish,
 218         .stop_streaming = uvc_stop_streaming,
 219 };
 220
 221 int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type,
 222                     int drop_corrupted)
 223 {
 224         int ret;
 225
 226         queue->queue.type = type;
 227         queue->queue.io_modes = VB2_MMAP | VB2_USERPTR;
 228         queue->queue.drv_priv = queue;
 229         queue->queue.buf_struct_size = sizeof(struct uvc_buffer);
 230         queue->queue.mem_ops = &vb2_vmalloc_memops;
 231         queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC
 232                 | V4L2_BUF_FLAG_TSTAMP_SRC_SOE;
 233         queue->queue.lock = &queue->mutex;
 234
 235         switch (type) {
 236         case V4L2_BUF_TYPE_META_CAPTURE:
 237                 queue->queue.ops = &uvc_meta_queue_qops;
 238                 break;
 239         default:
 240                 queue->queue.io_modes |= VB2_DMABUF;
 241                 queue->queue.ops = &uvc_queue_qops;
 242                 break;
 243         }
 244
 245         ret = vb2_queue_init(&queue->queue);
 246         if (ret)
 247                 return ret;
 248
 249         mutex_init(&queue->mutex);
 250         spin_lock_init(&queue->irqlock);
 251         INIT_LIST_HEAD(&queue->irqqueue);
 252         queue->flags = drop_corrupted ? UVC_QUEUE_DROP_CORRUPTED : 0;
 253
 254         return 0;
 255 }
 256
 257 void uvc_queue_release(struct uvc_video_queue *queue)
 258 {
 259         mutex_lock(&queue->mutex);
 260         vb2_queue_release(&queue->queue);
 261         mutex_unlock(&queue->mutex);
 262 }
 263
 264 /* -----------------------------------------------------------------------------
 265  * V4L2 queue operations
 266  */
 267
 268 int uvc_request_buffers(struct uvc_video_queue *queue,
 269                         struct v4l2_requestbuffers *rb)
 270 {
 271         int ret;
 272
 273         mutex_lock(&queue->mutex);
 274         ret = vb2_reqbufs(&queue->queue, rb);
 275         mutex_unlock(&queue->mutex);
 276
 277         return ret ? ret : rb->count;
 278 }
 279
 280 int uvc_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
 281 {
 282         int ret;
 283
 284         mutex_lock(&queue->mutex);
 285         ret = vb2_querybuf(&queue->queue, buf);
 286         mutex_unlock(&queue->mutex);
 287
 288         return ret;
 289 }
 290
 291 int uvc_create_buffers(struct uvc_video_queue *queue,
 292                        struct v4l2_create_buffers *cb)
 293 {
 294         int ret;
 295
 296         mutex_lock(&queue->mutex);
 297         ret = vb2_create_bufs(&queue->queue, cb);
 298         mutex_unlock(&queue->mutex);
 299
 300         return ret;
 301 }
 302
 303 int uvc_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
 304 {
 305         int ret;
 306
 307         mutex_lock(&queue->mutex);
 308         ret = vb2_qbuf(&queue->queue, buf);
 309         mutex_unlock(&queue->mutex);
 310
 311         return ret;
 312 }
 313
 314 int uvc_export_buffer(struct uvc_video_queue *queue,
 315                       struct v4l2_exportbuffer *exp)
 316 {
 317         int ret;
 318
 319         mutex_lock(&queue->mutex);
 320         ret = vb2_expbuf(&queue->queue, exp);
 321         mutex_unlock(&queue->mutex);
 322
 323         return ret;
 324 }
 325
 326 int uvc_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf,
 327                        int nonblocking)
 328 {
 329         int ret;
 330
 331         mutex_lock(&queue->mutex);
 332         ret = vb2_dqbuf(&queue->queue, buf, nonblocking);
 333         mutex_unlock(&queue->mutex);
 334
 335         return ret;
 336 }
 337
 338 int uvc_queue_streamon(struct uvc_video_queue *queue, enum v4l2_buf_type type)
 339 {
 340         int ret;
 341
 342         mutex_lock(&queue->mutex);
 343         ret = vb2_streamon(&queue->queue, type);
 344         mutex_unlock(&queue->mutex);
 345
 346         return ret;
 347 }
 348
 349 int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type)
 350 {
 351         int ret;
 352
 353         mutex_lock(&queue->mutex);
 354         ret = vb2_streamoff(&queue->queue, type);
 355         mutex_unlock(&queue->mutex);
 356
 357         return ret;
 358 }
 359
 360 int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
 361 {
 362         return vb2_mmap(&queue->queue, vma);
 363 }
 364
 365 #ifndef CONFIG_MMU
 366 unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
 367                 unsigned long pgoff)
 368 {
 369         return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
 370 }
 371 #endif
 372
 373 __poll_t uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
 374                             poll_table *wait)
 375 {
 376         __poll_t ret;
 377
 378         mutex_lock(&queue->mutex);
 379         ret = vb2_poll(&queue->queue, file, wait);
 380         mutex_unlock(&queue->mutex);
 381
 382         return ret;
 383 }
 384
 385 /* -----------------------------------------------------------------------------
 386  *
 387  */
 388
 389 /*
 390  * Check if buffers have been allocated.
 391  */
 392 int uvc_queue_allocated(struct uvc_video_queue *queue)
 393 {
 394         int allocated;
 395
 396         mutex_lock(&queue->mutex);
 397         allocated = vb2_is_busy(&queue->queue);
 398         mutex_unlock(&queue->mutex);
 399
 400         return allocated;
 401 }
 402
 403 /*
 404  * Cancel the video buffers queue.
 405  *
 406  * Cancelling the queue marks all buffers on the irq queue as erroneous,
 407  * wakes them up and removes them from the queue.
 408  *
 409  * If the disconnect parameter is set, further calls to uvc_queue_buffer will
 410  * fail with -ENODEV.
 411  *
 412  * This function acquires the irq spinlock and can be called from interrupt
 413  * context.
 414  */
 415 void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect)
 416 {
 417         unsigned long flags;
 418
 419         spin_lock_irqsave(&queue->irqlock, flags);
 420         uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
 421         /* This must be protected by the irqlock spinlock to avoid race
 422          * conditions between uvc_buffer_queue and the disconnection event that
 423          * could result in an interruptible wait in uvc_dequeue_buffer. Do not
 424          * blindly replace this logic by checking for the UVC_QUEUE_DISCONNECTED
 425          * state outside the queue code.
 426          */
 427         if (disconnect)
 428                 queue->flags |= UVC_QUEUE_DISCONNECTED;
 429         spin_unlock_irqrestore(&queue->irqlock, flags);
 430 }
 431
 432 struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
 433                 struct uvc_buffer *buf)
 434 {
 435         struct uvc_buffer *nextbuf;
 436         unsigned long flags;
 437
 438         if ((queue->flags & UVC_QUEUE_DROP_CORRUPTED) && buf->error) {
 439                 buf->error = 0;
 440                 buf->state = UVC_BUF_STATE_QUEUED;
 441                 buf->bytesused = 0;
 442                 vb2_set_plane_payload(&buf->buf.vb2_buf, 0, 0);
 443                 return buf;
 444         }
 445
 446         spin_lock_irqsave(&queue->irqlock, flags);
 447         list_del(&buf->queue);
 448         if (!list_empty(&queue->irqqueue))
 449                 nextbuf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
 450                                            queue);
 451         else
 452                 nextbuf = NULL;
 453         spin_unlock_irqrestore(&queue->irqlock, flags);
 454
 455         buf->state = buf->error ? UVC_BUF_STATE_ERROR : UVC_BUF_STATE_DONE;
 456         vb2_set_plane_payload(&buf->buf.vb2_buf, 0, buf->bytesused);
 457         vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_DONE);
 458
 459         return nextbuf;
 460 }