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 struct v4l2_format *fmt,
73 unsigned int *nbuffers, unsigned int *nplanes,
74 unsigned int sizes[], void *alloc_ctxs[])
76 struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
77 struct uvc_streaming *stream = uvc_queue_to_stream(queue);
79 /* Make sure the image size is large enough. */
80 if (fmt && fmt->fmt.pix.sizeimage < stream->ctrl.dwMaxVideoFrameSize)
85 sizes[0] = fmt ? fmt->fmt.pix.sizeimage
86 : stream->ctrl.dwMaxVideoFrameSize;
91 static int uvc_buffer_prepare(struct vb2_buffer *vb)
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);
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");
103 if (unlikely(queue->flags & UVC_QUEUE_DISCONNECTED))
106 buf->state = UVC_BUF_STATE_QUEUED;
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)
113 buf->bytesused = vb2_get_plane_payload(vb, 0);
118 static void uvc_buffer_queue(struct vb2_buffer *vb)
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);
125 spin_lock_irqsave(&queue->irqlock, flags);
126 if (likely(!(queue->flags & UVC_QUEUE_DISCONNECTED))) {
127 list_add_tail(&buf->queue, &queue->irqqueue);
129 /* If the device is disconnected return the buffer to userspace
130 * directly. The next QBUF call will fail with -ENODEV.
132 buf->state = UVC_BUF_STATE_ERROR;
133 vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
136 spin_unlock_irqrestore(&queue->irqlock, flags);
139 static void uvc_buffer_finish(struct vb2_buffer *vb)
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);
146 if (vb->state == VB2_BUF_STATE_DONE)
147 uvc_video_clock_update(stream, vbuf, buf);
150 static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count)
152 struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
153 struct uvc_streaming *stream = uvc_queue_to_stream(queue);
159 ret = uvc_video_enable(stream, 1);
163 spin_lock_irqsave(&queue->irqlock, flags);
164 uvc_queue_return_buffers(queue, UVC_BUF_STATE_QUEUED);
165 spin_unlock_irqrestore(&queue->irqlock, flags);
170 static void uvc_stop_streaming(struct vb2_queue *vq)
172 struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
173 struct uvc_streaming *stream = uvc_queue_to_stream(queue);
176 uvc_video_enable(stream, 0);
178 spin_lock_irqsave(&queue->irqlock, flags);
179 uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
180 spin_unlock_irqrestore(&queue->irqlock, flags);
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,
194 int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type,
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);
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;
220 void uvc_queue_release(struct uvc_video_queue *queue)
222 mutex_lock(&queue->mutex);
223 vb2_queue_release(&queue->queue);
224 mutex_unlock(&queue->mutex);
227 /* -----------------------------------------------------------------------------
228 * V4L2 queue operations
231 int uvc_request_buffers(struct uvc_video_queue *queue,
232 struct v4l2_requestbuffers *rb)
236 mutex_lock(&queue->mutex);
237 ret = vb2_reqbufs(&queue->queue, rb);
238 mutex_unlock(&queue->mutex);
240 return ret ? ret : rb->count;
243 int uvc_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
247 mutex_lock(&queue->mutex);
248 ret = vb2_querybuf(&queue->queue, buf);
249 mutex_unlock(&queue->mutex);
254 int uvc_create_buffers(struct uvc_video_queue *queue,
255 struct v4l2_create_buffers *cb)
259 mutex_lock(&queue->mutex);
260 ret = vb2_create_bufs(&queue->queue, cb);
261 mutex_unlock(&queue->mutex);
266 int uvc_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
270 mutex_lock(&queue->mutex);
271 ret = vb2_qbuf(&queue->queue, buf);
272 mutex_unlock(&queue->mutex);
277 int uvc_export_buffer(struct uvc_video_queue *queue,
278 struct v4l2_exportbuffer *exp)
282 mutex_lock(&queue->mutex);
283 ret = vb2_expbuf(&queue->queue, exp);
284 mutex_unlock(&queue->mutex);
289 int uvc_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf,
294 mutex_lock(&queue->mutex);
295 ret = vb2_dqbuf(&queue->queue, buf, nonblocking);
296 mutex_unlock(&queue->mutex);
301 int uvc_queue_streamon(struct uvc_video_queue *queue, enum v4l2_buf_type type)
305 mutex_lock(&queue->mutex);
306 ret = vb2_streamon(&queue->queue, type);
307 mutex_unlock(&queue->mutex);
312 int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type)
316 mutex_lock(&queue->mutex);
317 ret = vb2_streamoff(&queue->queue, type);
318 mutex_unlock(&queue->mutex);
323 int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
325 return vb2_mmap(&queue->queue, vma);
329 unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
332 return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
336 unsigned int uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
341 mutex_lock(&queue->mutex);
342 ret = vb2_poll(&queue->queue, file, wait);
343 mutex_unlock(&queue->mutex);
348 /* -----------------------------------------------------------------------------
353 * Check if buffers have been allocated.
355 int uvc_queue_allocated(struct uvc_video_queue *queue)
359 mutex_lock(&queue->mutex);
360 allocated = vb2_is_busy(&queue->queue);
361 mutex_unlock(&queue->mutex);
367 * Cancel the video buffers queue.
369 * Cancelling the queue marks all buffers on the irq queue as erroneous,
370 * wakes them up and removes them from the queue.
372 * If the disconnect parameter is set, further calls to uvc_queue_buffer will
375 * This function acquires the irq spinlock and can be called from interrupt
378 void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect)
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.
391 queue->flags |= UVC_QUEUE_DISCONNECTED;
392 spin_unlock_irqrestore(&queue->irqlock, flags);
395 struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
396 struct uvc_buffer *buf)
398 struct uvc_buffer *nextbuf;
401 if ((queue->flags & UVC_QUEUE_DROP_CORRUPTED) && buf->error) {
403 buf->state = UVC_BUF_STATE_QUEUED;
405 vb2_set_plane_payload(&buf->buf.vb2_buf, 0, 0);
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,
416 spin_unlock_irqrestore(&queue->irqlock, flags);
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);