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);
47 * Return all queued buffers to videobuf2 in the requested state.
49 * This function must be called with the queue spinlock held.
51 static void uvc_queue_return_buffers(struct uvc_video_queue *queue,
52 enum uvc_buffer_state state)
54 enum vb2_buffer_state vb2_state = state == UVC_BUF_STATE_ERROR
56 : VB2_BUF_STATE_QUEUED;
58 while (!list_empty(&queue->irqqueue)) {
59 struct uvc_buffer *buf = list_first_entry(&queue->irqqueue,
62 list_del(&buf->queue);
64 vb2_buffer_done(&buf->buf.vb2_buf, vb2_state);
68 /* -----------------------------------------------------------------------------
69 * videobuf2 queue operations
72 static int uvc_queue_setup(struct vb2_queue *vq, const void *parg,
73 unsigned int *nbuffers, unsigned int *nplanes,
74 unsigned int sizes[], void *alloc_ctxs[])
76 const struct v4l2_format *fmt = parg;
77 struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
78 struct uvc_streaming *stream = uvc_queue_to_stream(queue);
80 /* Make sure the image size is large enough. */
81 if (fmt && fmt->fmt.pix.sizeimage < stream->ctrl.dwMaxVideoFrameSize)
86 sizes[0] = fmt ? fmt->fmt.pix.sizeimage
87 : stream->ctrl.dwMaxVideoFrameSize;
92 static int uvc_buffer_prepare(struct vb2_buffer *vb)
94 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
95 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
96 struct uvc_buffer *buf = container_of(vbuf, struct uvc_buffer, buf);
98 if (vb->type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
99 vb2_get_plane_payload(vb, 0) > vb2_plane_size(vb, 0)) {
100 uvc_trace(UVC_TRACE_CAPTURE, "[E] Bytes used out of bounds.\n");
104 if (unlikely(queue->flags & UVC_QUEUE_DISCONNECTED))
107 buf->state = UVC_BUF_STATE_QUEUED;
109 buf->mem = vb2_plane_vaddr(vb, 0);
110 buf->length = vb2_plane_size(vb, 0);
111 if (vb->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
114 buf->bytesused = vb2_get_plane_payload(vb, 0);
119 static void uvc_buffer_queue(struct vb2_buffer *vb)
121 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
122 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
123 struct uvc_buffer *buf = container_of(vbuf, struct uvc_buffer, buf);
126 spin_lock_irqsave(&queue->irqlock, flags);
127 if (likely(!(queue->flags & UVC_QUEUE_DISCONNECTED))) {
128 list_add_tail(&buf->queue, &queue->irqqueue);
130 /* If the device is disconnected return the buffer to userspace
131 * directly. The next QBUF call will fail with -ENODEV.
133 buf->state = UVC_BUF_STATE_ERROR;
134 vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
137 spin_unlock_irqrestore(&queue->irqlock, flags);
140 static void uvc_buffer_finish(struct vb2_buffer *vb)
142 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
143 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
144 struct uvc_streaming *stream = uvc_queue_to_stream(queue);
145 struct uvc_buffer *buf = container_of(vbuf, struct uvc_buffer, buf);
147 if (vb->state == VB2_BUF_STATE_DONE)
148 uvc_video_clock_update(stream, vbuf, buf);
151 static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count)
153 struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
154 struct uvc_streaming *stream = uvc_queue_to_stream(queue);
160 ret = uvc_video_enable(stream, 1);
164 spin_lock_irqsave(&queue->irqlock, flags);
165 uvc_queue_return_buffers(queue, UVC_BUF_STATE_QUEUED);
166 spin_unlock_irqrestore(&queue->irqlock, flags);
171 static void uvc_stop_streaming(struct vb2_queue *vq)
173 struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
174 struct uvc_streaming *stream = uvc_queue_to_stream(queue);
177 uvc_video_enable(stream, 0);
179 spin_lock_irqsave(&queue->irqlock, flags);
180 uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
181 spin_unlock_irqrestore(&queue->irqlock, flags);
184 static struct vb2_ops uvc_queue_qops = {
185 .queue_setup = uvc_queue_setup,
186 .buf_prepare = uvc_buffer_prepare,
187 .buf_queue = uvc_buffer_queue,
188 .buf_finish = uvc_buffer_finish,
189 .wait_prepare = vb2_ops_wait_prepare,
190 .wait_finish = vb2_ops_wait_finish,
191 .start_streaming = uvc_start_streaming,
192 .stop_streaming = uvc_stop_streaming,
195 int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type,
200 queue->queue.type = type;
201 queue->queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
202 queue->queue.drv_priv = queue;
203 queue->queue.buf_struct_size = sizeof(struct uvc_buffer);
204 queue->queue.ops = &uvc_queue_qops;
205 queue->queue.mem_ops = &vb2_vmalloc_memops;
206 queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC
207 | V4L2_BUF_FLAG_TSTAMP_SRC_SOE;
208 queue->queue.lock = &queue->mutex;
209 ret = vb2_queue_init(&queue->queue);
213 mutex_init(&queue->mutex);
214 spin_lock_init(&queue->irqlock);
215 INIT_LIST_HEAD(&queue->irqqueue);
216 queue->flags = drop_corrupted ? UVC_QUEUE_DROP_CORRUPTED : 0;
221 void uvc_queue_release(struct uvc_video_queue *queue)
223 mutex_lock(&queue->mutex);
224 vb2_queue_release(&queue->queue);
225 mutex_unlock(&queue->mutex);
228 /* -----------------------------------------------------------------------------
229 * V4L2 queue operations
232 int uvc_request_buffers(struct uvc_video_queue *queue,
233 struct v4l2_requestbuffers *rb)
237 mutex_lock(&queue->mutex);
238 ret = vb2_reqbufs(&queue->queue, rb);
239 mutex_unlock(&queue->mutex);
241 return ret ? ret : rb->count;
244 int uvc_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
248 mutex_lock(&queue->mutex);
249 ret = vb2_querybuf(&queue->queue, buf);
250 mutex_unlock(&queue->mutex);
255 int uvc_create_buffers(struct uvc_video_queue *queue,
256 struct v4l2_create_buffers *cb)
260 mutex_lock(&queue->mutex);
261 ret = vb2_create_bufs(&queue->queue, cb);
262 mutex_unlock(&queue->mutex);
267 int uvc_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
271 mutex_lock(&queue->mutex);
272 ret = vb2_qbuf(&queue->queue, buf);
273 mutex_unlock(&queue->mutex);
278 int uvc_export_buffer(struct uvc_video_queue *queue,
279 struct v4l2_exportbuffer *exp)
283 mutex_lock(&queue->mutex);
284 ret = vb2_expbuf(&queue->queue, exp);
285 mutex_unlock(&queue->mutex);
290 int uvc_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf,
295 mutex_lock(&queue->mutex);
296 ret = vb2_dqbuf(&queue->queue, buf, nonblocking);
297 mutex_unlock(&queue->mutex);
302 int uvc_queue_streamon(struct uvc_video_queue *queue, enum v4l2_buf_type type)
306 mutex_lock(&queue->mutex);
307 ret = vb2_streamon(&queue->queue, type);
308 mutex_unlock(&queue->mutex);
313 int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type)
317 mutex_lock(&queue->mutex);
318 ret = vb2_streamoff(&queue->queue, type);
319 mutex_unlock(&queue->mutex);
324 int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
326 return vb2_mmap(&queue->queue, vma);
330 unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
333 return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
337 unsigned int uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
342 mutex_lock(&queue->mutex);
343 ret = vb2_poll(&queue->queue, file, wait);
344 mutex_unlock(&queue->mutex);
349 /* -----------------------------------------------------------------------------
354 * Check if buffers have been allocated.
356 int uvc_queue_allocated(struct uvc_video_queue *queue)
360 mutex_lock(&queue->mutex);
361 allocated = vb2_is_busy(&queue->queue);
362 mutex_unlock(&queue->mutex);
368 * Cancel the video buffers queue.
370 * Cancelling the queue marks all buffers on the irq queue as erroneous,
371 * wakes them up and removes them from the queue.
373 * If the disconnect parameter is set, further calls to uvc_queue_buffer will
376 * This function acquires the irq spinlock and can be called from interrupt
379 void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect)
383 spin_lock_irqsave(&queue->irqlock, flags);
384 uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
385 /* This must be protected by the irqlock spinlock to avoid race
386 * conditions between uvc_buffer_queue and the disconnection event that
387 * could result in an interruptible wait in uvc_dequeue_buffer. Do not
388 * blindly replace this logic by checking for the UVC_QUEUE_DISCONNECTED
389 * state outside the queue code.
392 queue->flags |= UVC_QUEUE_DISCONNECTED;
393 spin_unlock_irqrestore(&queue->irqlock, flags);
396 struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
397 struct uvc_buffer *buf)
399 struct uvc_buffer *nextbuf;
402 if ((queue->flags & UVC_QUEUE_DROP_CORRUPTED) && buf->error) {
404 buf->state = UVC_BUF_STATE_QUEUED;
406 vb2_set_plane_payload(&buf->buf.vb2_buf, 0, 0);
410 spin_lock_irqsave(&queue->irqlock, flags);
411 list_del(&buf->queue);
412 if (!list_empty(&queue->irqqueue))
413 nextbuf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
417 spin_unlock_irqrestore(&queue->irqlock, flags);
419 buf->state = buf->error ? VB2_BUF_STATE_ERROR : UVC_BUF_STATE_DONE;
420 vb2_set_plane_payload(&buf->buf.vb2_buf, 0, buf->bytesused);
421 vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_DONE);