int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
{
struct vb2_buffer *vb;
int ret;
if (q->fileio) {
dprintk(1, "streamon: file io in progress\n");
return -EBUSY;
}
if (type != q->type) {
dprintk(1, "streamon: invalid stream type\n");
return -EINVAL;
}
if (q->streaming) {
dprintk(1, "streamon: already streaming\n");
return -EBUSY;
}
list_for_each_entry(vb, &q->queued_list, queued_entry)
__enqueue_in_driver(vb);
ret = call_qop(q, start_streaming, q, atomic_read(&q->queued_count));
if (ret) {
dprintk(1, "streamon: driver refused to start streaming\n");
__vb2_queue_cancel(q);
return ret;
}
q->streaming = 1;
dprintk(3, "Streamon successful\n");
return 0;
}
/**
* vb2_streamon - start streaming
* @q: videobuf2 queue
* @type: type argument passed from userspace to vidioc_streamon handler
*
* Should be called from vidioc_streamon handler of a driver.
* This function:
* 1) verifies current state
* 2) starts streaming and passes any previously queued buffers to the driver
*
* The return values from this function are intended to be directly returned
* from vidioc_streamon handler in the driver.
*/
int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
{
struct vb2_buffer *vb;
int ret;
if (q->fileio) {
dprintk(1, "streamon: file io in progress\n");
return -EBUSY;
}
if (type != q->type) {
dprintk(1, "streamon: invalid stream type\n");
return -EINVAL;
}
if (q->streaming) {
dprintk(1, "streamon: already streaming\n");
return -EBUSY;
}
/*
* Cannot start streaming on an OUTPUT device if no buffers have
* been queued yet.
*/
if (V4L2_TYPE_IS_OUTPUT(q->type)) {
if (list_empty(&q->queued_list)) {
dprintk(1, "streamon: no output buffers queued\n");
return -EINVAL;
}
}
/*
* Let driver notice that streaming state has been enabled.
*/
ret = call_qop(q, start_streaming, q);
if (ret) {
dprintk(1, "streamon: driver refused to start streaming\n");
return ret;
}
q->streaming = 1;
/*
* If any buffers were queued before streamon,
* we can now pass them to driver for processing.
*/
list_for_each_entry(vb, &q->queued_list, queued_entry)
__enqueue_in_driver(vb);
dprintk(3, "Streamon successful\n");
return 0;
}
/**
* vb2_qbuf() - Queue a buffer from userspace
* @q: videobuf2 queue
* @b: buffer structure passed from userspace to vidioc_qbuf handler
* in driver
*
* Should be called from vidioc_qbuf ioctl handler of a driver.
* This function:
* 1) verifies the passed buffer,
* 2) calls buf_prepare callback in the driver (if provided), in which
* driver-specific buffer initialization can be performed,
* 3) if streaming is on, queues the buffer in driver by the means of buf_queue
* callback for processing.
*
* The return values from this function are intended to be directly returned
* from vidioc_qbuf handler in driver.
*/
int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
{
struct vb2_buffer *vb;
int ret = 0;
if (q->fileio) {
dprintk(1, "qbuf: file io in progress\n");
return -EBUSY;
}
if (b->type != q->type) {
dprintk(1, "qbuf: invalid buffer type\n");
return -EINVAL;
}
if (b->index >= q->num_buffers) {
dprintk(1, "qbuf: buffer index out of range\n");
return -EINVAL;
}
vb = q->bufs[b->index];
if (NULL == vb) {
/* Should never happen */
dprintk(1, "qbuf: buffer is NULL\n");
return -EINVAL;
}
if (b->memory != q->memory) {
dprintk(1, "qbuf: invalid memory type\n");
return -EINVAL;
}
if (vb->state != VB2_BUF_STATE_DEQUEUED) {
dprintk(1, "qbuf: buffer already in use\n");
return -EINVAL;
}
if (q->memory == V4L2_MEMORY_MMAP)
ret = __qbuf_mmap(vb, b);
else if (q->memory == V4L2_MEMORY_USERPTR)
ret = __qbuf_userptr(vb, b);
else {
WARN(1, "Invalid queue type\n");
return -EINVAL;
}
if (ret)
return ret;
ret = call_qop(q, buf_prepare, vb);
if (ret) {
dprintk(1, "qbuf: buffer preparation failed\n");
return ret;
}
/*
* Add to the queued buffers list, a buffer will stay on it until
* dequeued in dqbuf.
*/
list_add_tail(&vb->queued_entry, &q->queued_list);
vb->state = VB2_BUF_STATE_QUEUED;
/*
* If already streaming, give the buffer to driver for processing.
* If not, the buffer will be given to driver on next streamon.
*/
if (q->streaming)
__enqueue_in_driver(vb);
dprintk(1, "qbuf of buffer %d succeeded\n", vb->v4l2_buf.index);
return 0;
}
int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
{
struct vb2_buffer *vb;
int ret = 0;
if (q->fileio) {
dprintk(1, "qbuf: file io in progress\n");
return -EBUSY;
}
if (b->type != q->type) {
dprintk(1, "qbuf: invalid buffer type\n");
return -EINVAL;
}
if (b->index >= q->num_buffers) {
dprintk(1, "qbuf: buffer index out of range\n");
return -EINVAL;
}
vb = q->bufs[b->index];
if (NULL == vb) {
dprintk(1, "qbuf: buffer is NULL\n");
return -EINVAL;
}
if (b->memory != q->memory) {
dprintk(1, "qbuf: invalid memory type\n");
return -EINVAL;
}
if (vb->state != VB2_BUF_STATE_DEQUEUED) {
dprintk(1, "qbuf: buffer already in use\n");
return -EINVAL;
}
if (q->memory == V4L2_MEMORY_MMAP)
ret = __qbuf_mmap(vb, b);
else if (q->memory == V4L2_MEMORY_USERPTR)
ret = __qbuf_userptr(vb, b);
else {
WARN(1, "Invalid queue type\n");
return -EINVAL;
}
if (ret)
return ret;
ret = call_qop(q, buf_prepare, vb);
if (ret) {
dprintk(1, "qbuf: buffer preparation failed\n");
return ret;
}
list_add_tail(&vb->queued_entry, &q->queued_list);
vb->state = VB2_BUF_STATE_QUEUED;
if (q->streaming)
__enqueue_in_driver(vb);
dprintk(1, "qbuf of buffer %d succeeded\n", vb->v4l2_buf.index);
return 0;
}
