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, const struct v4l2_format *fmt,
  73                            unsigned int *nbuffers, unsigned int *nplanes,
  74                            unsigned int sizes[], void *alloc_ctxs[])
  75 {
  76         struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
  77         struct uvc_streaming *stream = uvc_queue_to_stream(queue);
  78
  79         /* Make sure the image size is large enough. */
  80         if (fmt && fmt->fmt.pix.sizeimage < stream->ctrl.dwMaxVideoFrameSize)
  81                 return -EINVAL;
  82
  83         *nplanes = 1;
  84
  85         sizes[0] = fmt ? fmt->fmt.pix.sizeimage
  86                  : stream->ctrl.dwMaxVideoFrameSize;
  87
  88         return 0;
  89 }
  90
  91 static int uvc_buffer_prepare(struct vb2_buffer *vb)
  92 {
  93         struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
  94         struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
  95         struct uvc_buffer *buf = container_of(vbuf, struct uvc_buffer, buf);
  96
  97         if (vb->type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
  98             vb2_get_plane_payload(vb, 0) > vb2_plane_size(vb, 0)) {
  99                 uvc_trace(UVC_TRACE_CAPTURE, "[E] Bytes used out of bounds.\n");
 100                 return -EINVAL;
 101         }
 102
 103         if (unlikely(queue->flags & UVC_QUEUE_DISCONNECTED))
 104                 return -ENODEV;
 105
 106         buf->state = UVC_BUF_STATE_QUEUED;
 107         buf->error = 0;
 108         buf->mem = vb2_plane_vaddr(vb, 0);
 109         buf->length = vb2_plane_size(vb, 0);
 110         if (vb->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
 111                 buf->bytesused = 0;
 112         else
 113                 buf->bytesused = vb2_get_plane_payload(vb, 0);
 114
 115         return 0;
 116 }
 117
 118 static void uvc_buffer_queue(struct vb2_buffer *vb)
 119 {
 120         struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 121         struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
 122         struct uvc_buffer *buf = container_of(vbuf, struct uvc_buffer, buf);
 123         unsigned long flags;
 124
 125         spin_lock_irqsave(&queue->irqlock, flags);
 126         if (likely(!(queue->flags & UVC_QUEUE_DISCONNECTED))) {
 127                 list_add_tail(&buf->queue, &queue->irqqueue);
 128         } else {
 129                 /* If the device is disconnected return the buffer to userspace
 130                  * directly. The next QBUF call will fail with -ENODEV.
 131                  */
 132                 buf->state = UVC_BUF_STATE_ERROR;
 133                 vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
 134         }
 135
 136         spin_unlock_irqrestore(&queue->irqlock, flags);
 137 }
 138
 139 static void uvc_buffer_finish(struct vb2_buffer *vb)
 140 {
 141         struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 142         struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
 143         struct uvc_streaming *stream = uvc_queue_to_stream(queue);
 144         struct uvc_buffer *buf = container_of(vbuf, struct uvc_buffer, buf);
 145
 146         if (vb->state == VB2_BUF_STATE_DONE)
 147                 uvc_video_clock_update(stream, vbuf, buf);
 148 }
 149
 150 static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count)
 151 {
 152         struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
 153         struct uvc_streaming *stream = uvc_queue_to_stream(queue);
 154         unsigned long flags;
 155         int ret;
 156
 157         queue->buf_used = 0;
 158
 159         ret = uvc_video_enable(stream, 1);
 160         if (ret == 0)
 161                 return 0;
 162
 163         spin_lock_irqsave(&queue->irqlock, flags);
 164         uvc_queue_return_buffers(queue, UVC_BUF_STATE_QUEUED);
 165         spin_unlock_irqrestore(&queue->irqlock, flags);
 166
 167         return ret;
 168 }
 169
 170 static void uvc_stop_streaming(struct vb2_queue *vq)
 171 {
 172         struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
 173         struct uvc_streaming *stream = uvc_queue_to_stream(queue);
 174         unsigned long flags;
 175
 176         uvc_video_enable(stream, 0);
 177
 178         spin_lock_irqsave(&queue->irqlock, flags);
 179         uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
 180         spin_unlock_irqrestore(&queue->irqlock, flags);
 181 }
 182
 183 static struct vb2_ops uvc_queue_qops = {
 184         .queue_setup = uvc_queue_setup,
 185         .buf_prepare = uvc_buffer_prepare,
 186         .buf_queue = uvc_buffer_queue,
 187         .buf_finish = uvc_buffer_finish,
 188         .wait_prepare = vb2_ops_wait_prepare,
 189         .wait_finish = vb2_ops_wait_finish,
 190         .start_streaming = uvc_start_streaming,
 191         .stop_streaming = uvc_stop_streaming,
 192 };
 193
 194 int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type,
 195                     int drop_corrupted)
 196 {
 197         int ret;
 198
 199         queue->queue.type = type;
 200         queue->queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
 201         queue->queue.drv_priv = queue;
 202         queue->queue.buf_struct_size = sizeof(struct uvc_buffer);
 203         queue->queue.ops = &uvc_queue_qops;
 204         queue->queue.mem_ops = &vb2_vmalloc_memops;
 205         queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC
 206                 | V4L2_BUF_FLAG_TSTAMP_SRC_SOE;
 207         queue->queue.lock = &queue->mutex;
 208         ret = vb2_queue_init(&queue->queue);
 209         if (ret)
 210                 return ret;
 211
 212         mutex_init(&queue->mutex);
 213         spin_lock_init(&queue->irqlock);
 214         INIT_LIST_HEAD(&queue->irqqueue);
 215         queue->flags = drop_corrupted ? UVC_QUEUE_DROP_CORRUPTED : 0;
 216
 217         return 0;
 218 }
 219
 220 void uvc_queue_release(struct uvc_video_queue *queue)
 221 {
 222         mutex_lock(&queue->mutex);
 223         vb2_queue_release(&queue->queue);
 224         mutex_unlock(&queue->mutex);
 225 }
 226
 227 /* -----------------------------------------------------------------------------
 228  * V4L2 queue operations
 229  */
 230
 231 int uvc_request_buffers(struct uvc_video_queue *queue,
 232                         struct v4l2_requestbuffers *rb)
 233 {
 234         int ret;
 235
 236         mutex_lock(&queue->mutex);
 237         ret = vb2_reqbufs(&queue->queue, rb);
 238         mutex_unlock(&queue->mutex);
 239
 240         return ret ? ret : rb->count;
 241 }
 242
 243 int uvc_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
 244 {
 245         int ret;
 246
 247         mutex_lock(&queue->mutex);
 248         ret = vb2_querybuf(&queue->queue, buf);
 249         mutex_unlock(&queue->mutex);
 250
 251         return ret;
 252 }
 253
 254 int uvc_create_buffers(struct uvc_video_queue *queue,
 255                        struct v4l2_create_buffers *cb)
 256 {
 257         int ret;
 258
 259         mutex_lock(&queue->mutex);
 260         ret = vb2_create_bufs(&queue->queue, cb);
 261         mutex_unlock(&queue->mutex);
 262
 263         return ret;
 264 }
 265
 266 int uvc_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
 267 {
 268         int ret;
 269
 270         mutex_lock(&queue->mutex);
 271         ret = vb2_qbuf(&queue->queue, buf);
 272         mutex_unlock(&queue->mutex);
 273
 274         return ret;
 275 }
 276
 277 int uvc_export_buffer(struct uvc_video_queue *queue,
 278                       struct v4l2_exportbuffer *exp)
 279 {
 280         int ret;
 281
 282         mutex_lock(&queue->mutex);
 283         ret = vb2_expbuf(&queue->queue, exp);
 284         mutex_unlock(&queue->mutex);
 285
 286         return ret;
 287 }
 288
 289 int uvc_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf,
 290                        int nonblocking)
 291 {
 292         int ret;
 293
 294         mutex_lock(&queue->mutex);
 295         ret = vb2_dqbuf(&queue->queue, buf, nonblocking);
 296         mutex_unlock(&queue->mutex);
 297
 298         return ret;
 299 }
 300
 301 int uvc_queue_streamon(struct uvc_video_queue *queue, enum v4l2_buf_type type)
 302 {
 303         int ret;
 304
 305         mutex_lock(&queue->mutex);
 306         ret = vb2_streamon(&queue->queue, type);
 307         mutex_unlock(&queue->mutex);
 308
 309         return ret;
 310 }
 311
 312 int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type)
 313 {
 314         int ret;
 315
 316         mutex_lock(&queue->mutex);
 317         ret = vb2_streamoff(&queue->queue, type);
 318         mutex_unlock(&queue->mutex);
 319
 320         return ret;
 321 }
 322
 323 int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
 324 {
 325         return vb2_mmap(&queue->queue, vma);
 326 }
 327
 328 #ifndef CONFIG_MMU
 329 unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
 330                 unsigned long pgoff)
 331 {
 332         return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
 333 }
 334 #endif
 335
 336 unsigned int uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
 337                             poll_table *wait)
 338 {
 339         unsigned int ret;
 340
 341         mutex_lock(&queue->mutex);
 342         ret = vb2_poll(&queue->queue, file, wait);
 343         mutex_unlock(&queue->mutex);
 344
 345         return ret;
 346 }
 347
 348 /* -----------------------------------------------------------------------------
 349  *
 350  */
 351
 352 /*
 353  * Check if buffers have been allocated.
 354  */
 355 int uvc_queue_allocated(struct uvc_video_queue *queue)
 356 {
 357         int allocated;
 358
 359         mutex_lock(&queue->mutex);
 360         allocated = vb2_is_busy(&queue->queue);
 361         mutex_unlock(&queue->mutex);
 362
 363         return allocated;
 364 }
 365
 366 /*
 367  * Cancel the video buffers queue.
 368  *
 369  * Cancelling the queue marks all buffers on the irq queue as erroneous,
 370  * wakes them up and removes them from the queue.
 371  *
 372  * If the disconnect parameter is set, further calls to uvc_queue_buffer will
 373  * fail with -ENODEV.
 374  *
 375  * This function acquires the irq spinlock and can be called from interrupt
 376  * context.
 377  */
 378 void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect)
 379 {
 380         unsigned long flags;
 381
 382         spin_lock_irqsave(&queue->irqlock, flags);
 383         uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
 384         /* This must be protected by the irqlock spinlock to avoid race
 385          * conditions between uvc_buffer_queue and the disconnection event that
 386          * could result in an interruptible wait in uvc_dequeue_buffer. Do not
 387          * blindly replace this logic by checking for the UVC_QUEUE_DISCONNECTED
 388          * state outside the queue code.
 389          */
 390         if (disconnect)
 391                 queue->flags |= UVC_QUEUE_DISCONNECTED;
 392         spin_unlock_irqrestore(&queue->irqlock, flags);
 393 }
 394
 395 struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
 396                 struct uvc_buffer *buf)
 397 {
 398         struct uvc_buffer *nextbuf;
 399         unsigned long flags;
 400
 401         if ((queue->flags & UVC_QUEUE_DROP_CORRUPTED) && buf->error) {
 402                 buf->error = 0;
 403                 buf->state = UVC_BUF_STATE_QUEUED;
 404                 buf->bytesused = 0;
 405                 vb2_set_plane_payload(&buf->buf.vb2_buf, 0, 0);
 406                 return buf;
 407         }
 408
 409         spin_lock_irqsave(&queue->irqlock, flags);
 410         list_del(&buf->queue);
 411         if (!list_empty(&queue->irqqueue))
 412                 nextbuf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
 413                                            queue);
 414         else
 415                 nextbuf = NULL;
 416         spin_unlock_irqrestore(&queue->irqlock, flags);
 417
 418         buf->state = buf->error ? VB2_BUF_STATE_ERROR : UVC_BUF_STATE_DONE;
 419         vb2_set_plane_payload(&buf->buf.vb2_buf, 0, buf->bytesused);
 420         vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_DONE);
 421
 422         return nextbuf;
 423 }