2 * uvc_queue.c -- USB Video Class driver - Buffers management
4 * Copyright (C) 2005-2010
5 * Laurent Pinchart (laurent.pinchart@ideasonboard.com)
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.
14 #include <linux/atomic.h>
15 #include <linux/kernel.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>
28 /* ------------------------------------------------------------------------
29 * Video buffers queue management.
31 * Video queues is initialized by uvc_queue_init(). The function performs
32 * basic initialization of the uvc_video_queue struct and never fails.
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
40 static inline struct uvc_streaming *
41 uvc_queue_to_stream(struct uvc_video_queue *queue)
43 return container_of(queue, struct uvc_streaming, queue);
46 static inline struct uvc_buffer *uvc_vbuf_to_buffer(struct vb2_v4l2_buffer *buf)
48 return container_of(buf, struct uvc_buffer, buf);
52 * Return all queued buffers to videobuf2 in the requested state.
54 * This function must be called with the queue spinlock held.
56 static void uvc_queue_return_buffers(struct uvc_video_queue *queue,
57 enum uvc_buffer_state state)
59 enum vb2_buffer_state vb2_state = state == UVC_BUF_STATE_ERROR
61 : VB2_BUF_STATE_QUEUED;
63 while (!list_empty(&queue->irqqueue)) {
64 struct uvc_buffer *buf = list_first_entry(&queue->irqqueue,
67 list_del(&buf->queue);
69 vb2_buffer_done(&buf->buf.vb2_buf, vb2_state);
73 /* -----------------------------------------------------------------------------
74 * videobuf2 queue operations
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[])
81 struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
82 struct uvc_streaming *stream = uvc_queue_to_stream(queue);
83 unsigned size = stream->ctrl.dwMaxVideoFrameSize;
86 * When called with plane sizes, validate them. The driver supports
87 * single planar formats only, and requires buffers to be large enough
88 * to store a complete frame.
91 return *nplanes != 1 || sizes[0] < size ? -EINVAL : 0;
98 static int uvc_buffer_prepare(struct vb2_buffer *vb)
100 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
101 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
102 struct uvc_buffer *buf = uvc_vbuf_to_buffer(vbuf);
104 if (vb->type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
105 vb2_get_plane_payload(vb, 0) > vb2_plane_size(vb, 0)) {
106 uvc_trace(UVC_TRACE_CAPTURE, "[E] Bytes used out of bounds.\n");
110 if (unlikely(queue->flags & UVC_QUEUE_DISCONNECTED))
113 buf->state = UVC_BUF_STATE_QUEUED;
115 buf->mem = vb2_plane_vaddr(vb, 0);
116 buf->length = vb2_plane_size(vb, 0);
117 if (vb->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
120 buf->bytesused = vb2_get_plane_payload(vb, 0);
125 static void uvc_buffer_queue(struct vb2_buffer *vb)
127 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
128 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
129 struct uvc_buffer *buf = uvc_vbuf_to_buffer(vbuf);
132 spin_lock_irqsave(&queue->irqlock, flags);
133 if (likely(!(queue->flags & UVC_QUEUE_DISCONNECTED))) {
134 kref_init(&buf->ref);
135 list_add_tail(&buf->queue, &queue->irqqueue);
137 /* If the device is disconnected return the buffer to userspace
138 * directly. The next QBUF call will fail with -ENODEV.
140 buf->state = UVC_BUF_STATE_ERROR;
141 vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
144 spin_unlock_irqrestore(&queue->irqlock, flags);
147 static void uvc_buffer_finish(struct vb2_buffer *vb)
149 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
150 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
151 struct uvc_streaming *stream = uvc_queue_to_stream(queue);
152 struct uvc_buffer *buf = uvc_vbuf_to_buffer(vbuf);
154 if (vb->state == VB2_BUF_STATE_DONE)
155 uvc_video_clock_update(stream, vbuf, buf);
158 static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count)
160 struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
161 struct uvc_streaming *stream = uvc_queue_to_stream(queue);
167 ret = uvc_video_enable(stream, 1);
171 spin_lock_irqsave(&queue->irqlock, flags);
172 uvc_queue_return_buffers(queue, UVC_BUF_STATE_QUEUED);
173 spin_unlock_irqrestore(&queue->irqlock, flags);
178 static void uvc_stop_streaming(struct vb2_queue *vq)
180 struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
181 struct uvc_streaming *stream = uvc_queue_to_stream(queue);
183 /* Prevent new buffers coming in. */
184 spin_lock_irq(&queue->irqlock);
185 queue->flags |= UVC_QUEUE_STOPPING;
186 spin_unlock_irq(&queue->irqlock);
189 * All pending work should be completed before disabling the stream, as
190 * all URBs will be free'd during uvc_video_enable(s, 0).
192 flush_workqueue(stream->async_wq);
194 uvc_video_enable(stream, 0);
196 spin_lock_irq(&queue->irqlock);
197 uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
198 queue->flags &= ~UVC_QUEUE_STOPPING;
199 spin_unlock_irq(&queue->irqlock);
202 static const struct vb2_ops uvc_queue_qops = {
203 .queue_setup = uvc_queue_setup,
204 .buf_prepare = uvc_buffer_prepare,
205 .buf_queue = uvc_buffer_queue,
206 .buf_finish = uvc_buffer_finish,
207 .wait_prepare = vb2_ops_wait_prepare,
208 .wait_finish = vb2_ops_wait_finish,
209 .start_streaming = uvc_start_streaming,
210 .stop_streaming = uvc_stop_streaming,
213 int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type,
218 queue->queue.type = type;
219 queue->queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
220 queue->queue.drv_priv = queue;
221 queue->queue.buf_struct_size = sizeof(struct uvc_buffer);
222 queue->queue.ops = &uvc_queue_qops;
223 queue->queue.mem_ops = &vb2_vmalloc_memops;
224 queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC
225 | V4L2_BUF_FLAG_TSTAMP_SRC_SOE;
226 queue->queue.lock = &queue->mutex;
227 ret = vb2_queue_init(&queue->queue);
231 mutex_init(&queue->mutex);
232 spin_lock_init(&queue->irqlock);
233 INIT_LIST_HEAD(&queue->irqqueue);
234 queue->flags = drop_corrupted ? UVC_QUEUE_DROP_CORRUPTED : 0;
239 void uvc_queue_release(struct uvc_video_queue *queue)
241 mutex_lock(&queue->mutex);
242 vb2_queue_release(&queue->queue);
243 mutex_unlock(&queue->mutex);
246 /* -----------------------------------------------------------------------------
247 * V4L2 queue operations
250 int uvc_request_buffers(struct uvc_video_queue *queue,
251 struct v4l2_requestbuffers *rb)
255 mutex_lock(&queue->mutex);
256 ret = vb2_reqbufs(&queue->queue, rb);
257 mutex_unlock(&queue->mutex);
259 return ret ? ret : rb->count;
262 int uvc_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
266 mutex_lock(&queue->mutex);
267 ret = vb2_querybuf(&queue->queue, buf);
268 mutex_unlock(&queue->mutex);
273 int uvc_create_buffers(struct uvc_video_queue *queue,
274 struct v4l2_create_buffers *cb)
278 mutex_lock(&queue->mutex);
279 ret = vb2_create_bufs(&queue->queue, cb);
280 mutex_unlock(&queue->mutex);
285 int uvc_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
289 mutex_lock(&queue->mutex);
290 ret = vb2_qbuf(&queue->queue, buf);
291 mutex_unlock(&queue->mutex);
296 int uvc_export_buffer(struct uvc_video_queue *queue,
297 struct v4l2_exportbuffer *exp)
301 mutex_lock(&queue->mutex);
302 ret = vb2_expbuf(&queue->queue, exp);
303 mutex_unlock(&queue->mutex);
308 int uvc_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf,
313 mutex_lock(&queue->mutex);
314 ret = vb2_dqbuf(&queue->queue, buf, nonblocking);
315 mutex_unlock(&queue->mutex);
320 int uvc_queue_streamon(struct uvc_video_queue *queue, enum v4l2_buf_type type)
324 mutex_lock(&queue->mutex);
325 ret = vb2_streamon(&queue->queue, type);
326 mutex_unlock(&queue->mutex);
331 int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type)
335 mutex_lock(&queue->mutex);
336 ret = vb2_streamoff(&queue->queue, type);
337 mutex_unlock(&queue->mutex);
342 int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
344 return vb2_mmap(&queue->queue, vma);
348 unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
351 return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
355 unsigned int uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
360 mutex_lock(&queue->mutex);
361 ret = vb2_poll(&queue->queue, file, wait);
362 mutex_unlock(&queue->mutex);
367 /* -----------------------------------------------------------------------------
372 * Check if buffers have been allocated.
374 int uvc_queue_allocated(struct uvc_video_queue *queue)
378 mutex_lock(&queue->mutex);
379 allocated = vb2_is_busy(&queue->queue);
380 mutex_unlock(&queue->mutex);
386 * Cancel the video buffers queue.
388 * Cancelling the queue marks all buffers on the irq queue as erroneous,
389 * wakes them up and removes them from the queue.
391 * If the disconnect parameter is set, further calls to uvc_queue_buffer will
394 * This function acquires the irq spinlock and can be called from interrupt
397 void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect)
401 spin_lock_irqsave(&queue->irqlock, flags);
402 uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
403 /* This must be protected by the irqlock spinlock to avoid race
404 * conditions between uvc_buffer_queue and the disconnection event that
405 * could result in an interruptible wait in uvc_dequeue_buffer. Do not
406 * blindly replace this logic by checking for the UVC_QUEUE_DISCONNECTED
407 * state outside the queue code.
410 queue->flags |= UVC_QUEUE_DISCONNECTED;
411 spin_unlock_irqrestore(&queue->irqlock, flags);
415 * uvc_queue_get_current_buffer: Obtain the current working output buffer
417 * Buffers may span multiple packets, and even URBs, therefore the active buffer
418 * remains on the queue until the EOF marker.
420 static struct uvc_buffer *
421 __uvc_queue_get_current_buffer(struct uvc_video_queue *queue)
423 if (!list_empty(&queue->irqqueue))
424 return list_first_entry(&queue->irqqueue, struct uvc_buffer,
430 struct uvc_buffer *uvc_queue_get_current_buffer(struct uvc_video_queue *queue)
432 struct uvc_buffer *nextbuf;
435 spin_lock_irqsave(&queue->irqlock, flags);
436 nextbuf = __uvc_queue_get_current_buffer(queue);
437 spin_unlock_irqrestore(&queue->irqlock, flags);
443 * uvc_queue_requeue: Requeue a buffer on our internal irqqueue
445 * Reuse a buffer through our internal queue without the need to 'prepare'
446 * The buffer will be returned to userspace through the uvc_buffer_queue call if
447 * the device has been disconnected
449 static void uvc_queue_requeue(struct uvc_video_queue *queue,
450 struct uvc_buffer *buf)
453 buf->state = UVC_BUF_STATE_QUEUED;
455 vb2_set_plane_payload(&buf->buf.vb2_buf, 0, 0);
457 uvc_buffer_queue(&buf->buf.vb2_buf);
460 static void uvc_queue_buffer_complete(struct kref *ref)
462 struct uvc_buffer *buf = container_of(ref, struct uvc_buffer, ref);
463 struct vb2_buffer *vb = &buf->buf.vb2_buf;
464 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
466 if ((queue->flags & UVC_QUEUE_DROP_CORRUPTED) && buf->error) {
467 uvc_queue_requeue(queue, buf);
471 buf->state = buf->error ? UVC_BUF_STATE_ERROR : UVC_BUF_STATE_DONE;
472 vb2_set_plane_payload(&buf->buf.vb2_buf, 0, buf->bytesused);
473 vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_DONE);
477 * Release a reference on the buffer. Complete the buffer when the last
478 * reference is released
480 void uvc_queue_buffer_release(struct uvc_buffer *buf)
482 kref_put(&buf->ref, uvc_queue_buffer_complete);
486 * Remove this buffer from the queue. Lifetime will persist while async actions
487 * are still running (if any), and uvc_queue_buffer_release will give the buffer
488 * back to VB2 when all users have completed.
490 struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
491 struct uvc_buffer *buf)
493 struct uvc_buffer *nextbuf;
496 spin_lock_irqsave(&queue->irqlock, flags);
497 list_del(&buf->queue);
498 nextbuf = __uvc_queue_get_current_buffer(queue);
499 spin_unlock_irqrestore(&queue->irqlock, flags);
501 uvc_queue_buffer_release(buf);