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-vmalloc.h>
27 /* ------------------------------------------------------------------------
28 * Video buffers queue management.
30 * Video queues is initialized by uvc_queue_init(). The function performs
31 * basic initialization of the uvc_video_queue struct and never fails.
33 * Video buffers are managed by videobuf2. The driver uses a mutex to protect
34 * the videobuf2 queue operations by serializing calls to videobuf2 and a
35 * spinlock to protect the IRQ queue that holds the buffers to be processed by
39 /* -----------------------------------------------------------------------------
40 * videobuf2 queue operations
43 static int uvc_queue_setup(struct vb2_queue *vq, const struct v4l2_format *fmt,
44 unsigned int *nbuffers, unsigned int *nplanes,
45 unsigned int sizes[], void *alloc_ctxs[])
47 struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
48 struct uvc_streaming *stream =
49 container_of(queue, struct uvc_streaming, queue);
51 /* Make sure the image size is large enough. */
52 if (fmt && fmt->fmt.pix.sizeimage < stream->ctrl.dwMaxVideoFrameSize)
57 sizes[0] = fmt ? fmt->fmt.pix.sizeimage
58 : stream->ctrl.dwMaxVideoFrameSize;
63 static int uvc_buffer_prepare(struct vb2_buffer *vb)
65 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
66 struct uvc_buffer *buf = container_of(vb, struct uvc_buffer, buf);
68 if (vb->v4l2_buf.type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
69 vb2_get_plane_payload(vb, 0) > vb2_plane_size(vb, 0)) {
70 uvc_trace(UVC_TRACE_CAPTURE, "[E] Bytes used out of bounds.\n");
74 if (unlikely(queue->flags & UVC_QUEUE_DISCONNECTED))
77 buf->state = UVC_BUF_STATE_QUEUED;
79 buf->mem = vb2_plane_vaddr(vb, 0);
80 buf->length = vb2_plane_size(vb, 0);
81 if (vb->v4l2_buf.type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
84 buf->bytesused = vb2_get_plane_payload(vb, 0);
89 static void uvc_buffer_queue(struct vb2_buffer *vb)
91 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
92 struct uvc_buffer *buf = container_of(vb, struct uvc_buffer, buf);
95 spin_lock_irqsave(&queue->irqlock, flags);
96 if (likely(!(queue->flags & UVC_QUEUE_DISCONNECTED))) {
97 list_add_tail(&buf->queue, &queue->irqqueue);
99 /* If the device is disconnected return the buffer to userspace
100 * directly. The next QBUF call will fail with -ENODEV.
102 buf->state = UVC_BUF_STATE_ERROR;
103 vb2_buffer_done(&buf->buf, VB2_BUF_STATE_ERROR);
106 spin_unlock_irqrestore(&queue->irqlock, flags);
109 static void uvc_buffer_finish(struct vb2_buffer *vb)
111 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
112 struct uvc_streaming *stream =
113 container_of(queue, struct uvc_streaming, queue);
114 struct uvc_buffer *buf = container_of(vb, struct uvc_buffer, buf);
116 if (vb->state == VB2_BUF_STATE_DONE)
117 uvc_video_clock_update(stream, &vb->v4l2_buf, buf);
120 static void uvc_wait_prepare(struct vb2_queue *vq)
122 struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
124 mutex_unlock(&queue->mutex);
127 static void uvc_wait_finish(struct vb2_queue *vq)
129 struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
131 mutex_lock(&queue->mutex);
134 static struct vb2_ops uvc_queue_qops = {
135 .queue_setup = uvc_queue_setup,
136 .buf_prepare = uvc_buffer_prepare,
137 .buf_queue = uvc_buffer_queue,
138 .buf_finish = uvc_buffer_finish,
139 .wait_prepare = uvc_wait_prepare,
140 .wait_finish = uvc_wait_finish,
143 int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type,
148 queue->queue.type = type;
149 queue->queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
150 queue->queue.drv_priv = queue;
151 queue->queue.buf_struct_size = sizeof(struct uvc_buffer);
152 queue->queue.ops = &uvc_queue_qops;
153 queue->queue.mem_ops = &vb2_vmalloc_memops;
154 queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC
155 | V4L2_BUF_FLAG_TSTAMP_SRC_SOE;
156 ret = vb2_queue_init(&queue->queue);
160 mutex_init(&queue->mutex);
161 spin_lock_init(&queue->irqlock);
162 INIT_LIST_HEAD(&queue->irqqueue);
163 queue->flags = drop_corrupted ? UVC_QUEUE_DROP_CORRUPTED : 0;
168 /* -----------------------------------------------------------------------------
169 * V4L2 queue operations
172 int uvc_alloc_buffers(struct uvc_video_queue *queue,
173 struct v4l2_requestbuffers *rb)
177 mutex_lock(&queue->mutex);
178 ret = vb2_reqbufs(&queue->queue, rb);
179 mutex_unlock(&queue->mutex);
181 return ret ? ret : rb->count;
184 void uvc_free_buffers(struct uvc_video_queue *queue)
186 mutex_lock(&queue->mutex);
187 vb2_queue_release(&queue->queue);
188 mutex_unlock(&queue->mutex);
191 int uvc_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
195 mutex_lock(&queue->mutex);
196 ret = vb2_querybuf(&queue->queue, buf);
197 mutex_unlock(&queue->mutex);
202 int uvc_create_buffers(struct uvc_video_queue *queue,
203 struct v4l2_create_buffers *cb)
207 mutex_lock(&queue->mutex);
208 ret = vb2_create_bufs(&queue->queue, cb);
209 mutex_unlock(&queue->mutex);
214 int uvc_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
218 mutex_lock(&queue->mutex);
219 ret = vb2_qbuf(&queue->queue, buf);
220 mutex_unlock(&queue->mutex);
225 int uvc_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf,
230 mutex_lock(&queue->mutex);
231 ret = vb2_dqbuf(&queue->queue, buf, nonblocking);
232 mutex_unlock(&queue->mutex);
237 int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
241 mutex_lock(&queue->mutex);
242 ret = vb2_mmap(&queue->queue, vma);
243 mutex_unlock(&queue->mutex);
249 unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
254 mutex_lock(&queue->mutex);
255 ret = vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
256 mutex_unlock(&queue->mutex);
261 unsigned int uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
266 mutex_lock(&queue->mutex);
267 ret = vb2_poll(&queue->queue, file, wait);
268 mutex_unlock(&queue->mutex);
273 /* -----------------------------------------------------------------------------
278 * Check if buffers have been allocated.
280 int uvc_queue_allocated(struct uvc_video_queue *queue)
284 mutex_lock(&queue->mutex);
285 allocated = vb2_is_busy(&queue->queue);
286 mutex_unlock(&queue->mutex);
292 * Enable or disable the video buffers queue.
294 * The queue must be enabled before starting video acquisition and must be
295 * disabled after stopping it. This ensures that the video buffers queue
296 * state can be properly initialized before buffers are accessed from the
299 * Enabling the video queue returns -EBUSY if the queue is already enabled.
301 * Disabling the video queue cancels the queue and removes all buffers from
304 * This function can't be called from interrupt context. Use
305 * uvc_queue_cancel() instead.
307 int uvc_queue_enable(struct uvc_video_queue *queue, int enable)
312 mutex_lock(&queue->mutex);
314 ret = vb2_streamon(&queue->queue, queue->queue.type);
320 ret = vb2_streamoff(&queue->queue, queue->queue.type);
324 spin_lock_irqsave(&queue->irqlock, flags);
325 INIT_LIST_HEAD(&queue->irqqueue);
326 spin_unlock_irqrestore(&queue->irqlock, flags);
330 mutex_unlock(&queue->mutex);
335 * Cancel the video buffers queue.
337 * Cancelling the queue marks all buffers on the irq queue as erroneous,
338 * wakes them up and removes them from the queue.
340 * If the disconnect parameter is set, further calls to uvc_queue_buffer will
343 * This function acquires the irq spinlock and can be called from interrupt
346 void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect)
348 struct uvc_buffer *buf;
351 spin_lock_irqsave(&queue->irqlock, flags);
352 while (!list_empty(&queue->irqqueue)) {
353 buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
355 list_del(&buf->queue);
356 buf->state = UVC_BUF_STATE_ERROR;
357 vb2_buffer_done(&buf->buf, VB2_BUF_STATE_ERROR);
359 /* This must be protected by the irqlock spinlock to avoid race
360 * conditions between uvc_buffer_queue and the disconnection event that
361 * could result in an interruptible wait in uvc_dequeue_buffer. Do not
362 * blindly replace this logic by checking for the UVC_QUEUE_DISCONNECTED
363 * state outside the queue code.
366 queue->flags |= UVC_QUEUE_DISCONNECTED;
367 spin_unlock_irqrestore(&queue->irqlock, flags);
370 struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
371 struct uvc_buffer *buf)
373 struct uvc_buffer *nextbuf;
376 if ((queue->flags & UVC_QUEUE_DROP_CORRUPTED) && buf->error) {
378 buf->state = UVC_BUF_STATE_QUEUED;
380 vb2_set_plane_payload(&buf->buf, 0, 0);
384 spin_lock_irqsave(&queue->irqlock, flags);
385 list_del(&buf->queue);
386 if (!list_empty(&queue->irqqueue))
387 nextbuf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
391 spin_unlock_irqrestore(&queue->irqlock, flags);
393 buf->state = buf->error ? VB2_BUF_STATE_ERROR : UVC_BUF_STATE_DONE;
394 vb2_set_plane_payload(&buf->buf, 0, buf->bytesused);
395 vb2_buffer_done(&buf->buf, VB2_BUF_STATE_DONE);