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 /*
  47  * Return all queued buffers to videobuf2 in the requested state.
  48  *
  49  * This function must be called with the queue spinlock held.
  50  */
  51 static void uvc_queue_return_buffers(struct uvc_video_queue *queue,
  52                                enum uvc_buffer_state state)
  53 {
  54         enum vb2_buffer_state vb2_state = state == UVC_BUF_STATE_ERROR
  55                                         ? VB2_BUF_STATE_ERROR
  56                                         : VB2_BUF_STATE_QUEUED;
  57
  58         while (!list_empty(&queue->irqqueue)) {
  59                 struct uvc_buffer *buf = list_first_entry(&queue->irqqueue,
  60                                                           struct uvc_buffer,
  61                                                           queue);
  62                 list_del(&buf->queue);
  63                 buf->state = state;
  64                 vb2_buffer_done(&buf->buf.vb2_buf, vb2_state);
  65         }
  66 }
  67
  68 /* -----------------------------------------------------------------------------
  69  * videobuf2 queue operations
  70  */
  71
  72 static int uvc_queue_setup(struct vb2_queue *vq,
  73                            unsigned int *nbuffers, unsigned int *nplanes,
  74                            unsigned int sizes[], struct device *alloc_devs[])
  75 {
  76         struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
  77         struct uvc_streaming *stream = uvc_queue_to_stream(queue);
  78         unsigned size = stream->ctrl.dwMaxVideoFrameSize;
  79
  80         /* Make sure the image size is large enough. */
  81         if (*nplanes)
  82                 return sizes[0] < size ? -EINVAL : 0;
  83         *nplanes = 1;
  84         sizes[0] = size;
  85         return 0;
  86 }
  87
  88 static int uvc_buffer_prepare(struct vb2_buffer *vb)
  89 {
  90         struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
  91         struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
  92         struct uvc_buffer *buf = container_of(vbuf, struct uvc_buffer, buf);
  93
  94         if (vb->type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
  95             vb2_get_plane_payload(vb, 0) > vb2_plane_size(vb, 0)) {
  96                 uvc_trace(UVC_TRACE_CAPTURE, "[E] Bytes used out of bounds.\n");
  97                 return -EINVAL;
  98         }
  99
 100         if (unlikely(queue->flags & UVC_QUEUE_DISCONNECTED))
 101                 return -ENODEV;
 102
 103         buf->state = UVC_BUF_STATE_QUEUED;
 104         buf->error = 0;
 105         buf->mem = vb2_plane_vaddr(vb, 0);
 106         buf->length = vb2_plane_size(vb, 0);
 107         if (vb->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
 108                 buf->bytesused = 0;
 109         else
 110                 buf->bytesused = vb2_get_plane_payload(vb, 0);
 111
 112         return 0;
 113 }
 114
 115 static void uvc_buffer_queue(struct vb2_buffer *vb)
 116 {
 117         struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 118         struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
 119         struct uvc_buffer *buf = container_of(vbuf, struct uvc_buffer, buf);
 120         unsigned long flags;
 121
 122         spin_lock_irqsave(&queue->irqlock, flags);
 123         if (likely(!(queue->flags & UVC_QUEUE_DISCONNECTED))) {
 124                 list_add_tail(&buf->queue, &queue->irqqueue);
 125         } else {
 126                 /* If the device is disconnected return the buffer to userspace
 127                  * directly. The next QBUF call will fail with -ENODEV.
 128                  */
 129                 buf->state = UVC_BUF_STATE_ERROR;
 130                 vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
 131         }
 132
 133         spin_unlock_irqrestore(&queue->irqlock, flags);
 134 }
 135
 136 static void uvc_buffer_finish(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_streaming *stream = uvc_queue_to_stream(queue);
 141         struct uvc_buffer *buf = container_of(vbuf, struct uvc_buffer, buf);
 142
 143         if (vb->state == VB2_BUF_STATE_DONE)
 144                 uvc_video_clock_update(stream, vbuf, buf);
 145 }
 146
 147 static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count)
 148 {
 149         struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
 150         struct uvc_streaming *stream = uvc_queue_to_stream(queue);
 151         unsigned long flags;
 152         int ret;
 153
 154         queue->buf_used = 0;
 155
 156         ret = uvc_video_enable(stream, 1);
 157         if (ret == 0)
 158                 return 0;
 159
 160         spin_lock_irqsave(&queue->irqlock, flags);
 161         uvc_queue_return_buffers(queue, UVC_BUF_STATE_QUEUED);
 162         spin_unlock_irqrestore(&queue->irqlock, flags);
 163
 164         return ret;
 165 }
 166
 167 static void uvc_stop_streaming(struct vb2_queue *vq)
 168 {
 169         struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
 170         struct uvc_streaming *stream = uvc_queue_to_stream(queue);
 171         unsigned long flags;
 172
 173         uvc_video_enable(stream, 0);
 174
 175         spin_lock_irqsave(&queue->irqlock, flags);
 176         uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
 177         spin_unlock_irqrestore(&queue->irqlock, flags);
 178 }
 179
 180 static const struct vb2_ops uvc_queue_qops = {
 181         .queue_setup = uvc_queue_setup,
 182         .buf_prepare = uvc_buffer_prepare,
 183         .buf_queue = uvc_buffer_queue,
 184         .buf_finish = uvc_buffer_finish,
 185         .wait_prepare = vb2_ops_wait_prepare,
 186         .wait_finish = vb2_ops_wait_finish,
 187         .start_streaming = uvc_start_streaming,
 188         .stop_streaming = uvc_stop_streaming,
 189 };
 190
 191 int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type,
 192                     int drop_corrupted)
 193 {
 194         int ret;
 195
 196         queue->queue.type = type;
 197         queue->queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
 198         queue->queue.drv_priv = queue;
 199         queue->queue.buf_struct_size = sizeof(struct uvc_buffer);
 200         queue->queue.ops = &uvc_queue_qops;
 201         queue->queue.mem_ops = &vb2_vmalloc_memops;
 202         queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC
 203                 | V4L2_BUF_FLAG_TSTAMP_SRC_SOE;
 204         queue->queue.lock = &queue->mutex;
 205         ret = vb2_queue_init(&queue->queue);
 206         if (ret)
 207                 return ret;
 208
 209         mutex_init(&queue->mutex);
 210         spin_lock_init(&queue->irqlock);
 211         INIT_LIST_HEAD(&queue->irqqueue);
 212         queue->flags = drop_corrupted ? UVC_QUEUE_DROP_CORRUPTED : 0;
 213
 214         return 0;
 215 }
 216
 217 void uvc_queue_release(struct uvc_video_queue *queue)
 218 {
 219         mutex_lock(&queue->mutex);
 220         vb2_queue_release(&queue->queue);
 221         mutex_unlock(&queue->mutex);
 222 }
 223
 224 /* -----------------------------------------------------------------------------
 225  * V4L2 queue operations
 226  */
 227
 228 int uvc_request_buffers(struct uvc_video_queue *queue,
 229                         struct v4l2_requestbuffers *rb)
 230 {
 231         int ret;
 232
 233         mutex_lock(&queue->mutex);
 234         ret = vb2_reqbufs(&queue->queue, rb);
 235         mutex_unlock(&queue->mutex);
 236
 237         return ret ? ret : rb->count;
 238 }
 239
 240 int uvc_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
 241 {
 242         int ret;
 243
 244         mutex_lock(&queue->mutex);
 245         ret = vb2_querybuf(&queue->queue, buf);
 246         mutex_unlock(&queue->mutex);
 247
 248         return ret;
 249 }
 250
 251 int uvc_create_buffers(struct uvc_video_queue *queue,
 252                        struct v4l2_create_buffers *cb)
 253 {
 254         int ret;
 255
 256         mutex_lock(&queue->mutex);
 257         ret = vb2_create_bufs(&queue->queue, cb);
 258         mutex_unlock(&queue->mutex);
 259
 260         return ret;
 261 }
 262
 263 int uvc_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
 264 {
 265         int ret;
 266
 267         mutex_lock(&queue->mutex);
 268         ret = vb2_qbuf(&queue->queue, buf);
 269         mutex_unlock(&queue->mutex);
 270
 271         return ret;
 272 }
 273
 274 int uvc_export_buffer(struct uvc_video_queue *queue,
 275                       struct v4l2_exportbuffer *exp)
 276 {
 277         int ret;
 278
 279         mutex_lock(&queue->mutex);
 280         ret = vb2_expbuf(&queue->queue, exp);
 281         mutex_unlock(&queue->mutex);
 282
 283         return ret;
 284 }
 285
 286 int uvc_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf,
 287                        int nonblocking)
 288 {
 289         int ret;
 290
 291         mutex_lock(&queue->mutex);
 292         ret = vb2_dqbuf(&queue->queue, buf, nonblocking);
 293         mutex_unlock(&queue->mutex);
 294
 295         return ret;
 296 }
 297
 298 int uvc_queue_streamon(struct uvc_video_queue *queue, enum v4l2_buf_type type)
 299 {
 300         int ret;
 301
 302         mutex_lock(&queue->mutex);
 303         ret = vb2_streamon(&queue->queue, type);
 304         mutex_unlock(&queue->mutex);
 305
 306         return ret;
 307 }
 308
 309 int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type)
 310 {
 311         int ret;
 312
 313         mutex_lock(&queue->mutex);
 314         ret = vb2_streamoff(&queue->queue, type);
 315         mutex_unlock(&queue->mutex);
 316
 317         return ret;
 318 }
 319
 320 int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
 321 {
 322         return vb2_mmap(&queue->queue, vma);
 323 }
 324
 325 #ifndef CONFIG_MMU
 326 unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
 327                 unsigned long pgoff)
 328 {
 329         return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
 330 }
 331 #endif
 332
 333 unsigned int uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
 334                             poll_table *wait)
 335 {
 336         unsigned int ret;
 337
 338         mutex_lock(&queue->mutex);
 339         ret = vb2_poll(&queue->queue, file, wait);
 340         mutex_unlock(&queue->mutex);
 341
 342         return ret;
 343 }
 344
 345 /* -----------------------------------------------------------------------------
 346  *
 347  */
 348
 349 /*
 350  * Check if buffers have been allocated.
 351  */
 352 int uvc_queue_allocated(struct uvc_video_queue *queue)
 353 {
 354         int allocated;
 355
 356         mutex_lock(&queue->mutex);
 357         allocated = vb2_is_busy(&queue->queue);
 358         mutex_unlock(&queue->mutex);
 359
 360         return allocated;
 361 }
 362
 363 /*
 364  * Cancel the video buffers queue.
 365  *
 366  * Cancelling the queue marks all buffers on the irq queue as erroneous,
 367  * wakes them up and removes them from the queue.
 368  *
 369  * If the disconnect parameter is set, further calls to uvc_queue_buffer will
 370  * fail with -ENODEV.
 371  *
 372  * This function acquires the irq spinlock and can be called from interrupt
 373  * context.
 374  */
 375 void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect)
 376 {
 377         unsigned long flags;
 378
 379         spin_lock_irqsave(&queue->irqlock, flags);
 380         uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
 381         /* This must be protected by the irqlock spinlock to avoid race
 382          * conditions between uvc_buffer_queue and the disconnection event that
 383          * could result in an interruptible wait in uvc_dequeue_buffer. Do not
 384          * blindly replace this logic by checking for the UVC_QUEUE_DISCONNECTED
 385          * state outside the queue code.
 386          */
 387         if (disconnect)
 388                 queue->flags |= UVC_QUEUE_DISCONNECTED;
 389         spin_unlock_irqrestore(&queue->irqlock, flags);
 390 }
 391
 392 struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
 393                 struct uvc_buffer *buf)
 394 {
 395         struct uvc_buffer *nextbuf;
 396         unsigned long flags;
 397
 398         if ((queue->flags & UVC_QUEUE_DROP_CORRUPTED) && buf->error) {
 399                 buf->error = 0;
 400                 buf->state = UVC_BUF_STATE_QUEUED;
 401                 buf->bytesused = 0;
 402                 vb2_set_plane_payload(&buf->buf.vb2_buf, 0, 0);
 403                 return buf;
 404         }
 405
 406         spin_lock_irqsave(&queue->irqlock, flags);
 407         list_del(&buf->queue);
 408         if (!list_empty(&queue->irqqueue))
 409                 nextbuf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
 410                                            queue);
 411         else
 412                 nextbuf = NULL;
 413         spin_unlock_irqrestore(&queue->irqlock, flags);
 414
 415         buf->state = buf->error ? VB2_BUF_STATE_ERROR : UVC_BUF_STATE_DONE;
 416         vb2_set_plane_payload(&buf->buf.vb2_buf, 0, buf->bytesused);
 417         vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_DONE);
 418
 419         return nextbuf;
 420 }