/**
* 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) passes any previously queued buffers to the driver and starts streaming
*
* 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)
{
if (vb2_fileio_is_active(q)) {
dprintk(1, "file io in progress\n");
return -EBUSY;
}
return vb2_core_streamon(q, type);
}
int dvb_vb2_stream_on(struct dvb_vb2_ctx *ctx)
{
struct vb2_queue *q = &ctx->vb_q;
int ret;
ret = vb2_core_streamon(q, q->type);
if (ret) {
ctx->state = DVB_VB2_STATE_NONE;
dprintk(1, "[%s] errno=%d\n", ctx->name, ret);
return ret;
}
ctx->state |= DVB_VB2_STATE_STREAMON;
dprintk(3, "[%s]\n", ctx->name);
return 0;
}
/**
* __vb2_init_fileio() - initialize file io emulator
* @q: videobuf2 queue
* @read: mode selector (1 means read, 0 means write)
*/
static int __vb2_init_fileio(struct vb2_queue *q, int read)
{
struct vb2_fileio_data *fileio;
int i, ret;
unsigned int count = 0;
/*
* Sanity check
*/
if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
(!read && !(q->io_modes & VB2_WRITE))))
return -EINVAL;
/*
* Check if device supports mapping buffers to kernel virtual space.
*/
if (!q->mem_ops->vaddr)
return -EBUSY;
/*
* Check if streaming api has not been already activated.
*/
if (q->streaming || q->num_buffers > 0)
return -EBUSY;
/*
* Start with count 1, driver can increase it in queue_setup()
*/
count = 1;
dprintk(3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
(read) ? "read" : "write", count, q->fileio_read_once,
q->fileio_write_immediately);
fileio = kzalloc(sizeof(struct vb2_fileio_data), GFP_KERNEL);
if (fileio == NULL)
return -ENOMEM;
fileio->read_once = q->fileio_read_once;
fileio->write_immediately = q->fileio_write_immediately;
/*
* Request buffers and use MMAP type to force driver
* to allocate buffers by itself.
*/
fileio->req.count = count;
fileio->req.memory = VB2_MEMORY_MMAP;
fileio->req.type = q->type;
q->fileio = fileio;
ret = vb2_core_reqbufs(q, fileio->req.memory, &fileio->req.count);
if (ret)
goto err_kfree;
/*
* Check if plane_count is correct
* (multiplane buffers are not supported).
*/
if (q->bufs[0]->num_planes != 1) {
ret = -EBUSY;
goto err_reqbufs;
}
/*
* Get kernel address of each buffer.
*/
for (i = 0; i < q->num_buffers; i++) {
fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
if (fileio->bufs[i].vaddr == NULL) {
ret = -EINVAL;
goto err_reqbufs;
}
fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
}
/*
* Read mode requires pre queuing of all buffers.
*/
if (read) {
bool is_multiplanar = q->is_multiplanar;
/*
* Queue all buffers.
*/
for (i = 0; i < q->num_buffers; i++) {
struct v4l2_buffer *b = &fileio->b;
memset(b, 0, sizeof(*b));
b->type = q->type;
if (is_multiplanar) {
memset(&fileio->p, 0, sizeof(fileio->p));
b->m.planes = &fileio->p;
b->length = 1;
}
b->memory = q->memory;
b->index = i;
ret = vb2_internal_qbuf(q, b);
if (ret)
goto err_reqbufs;
fileio->bufs[i].queued = 1;
}
/*
* All buffers have been queued, so mark that by setting
* initial_index to q->num_buffers
*/
fileio->initial_index = q->num_buffers;
fileio->cur_index = q->num_buffers;
}
/*
* Start streaming.
*/
ret = vb2_core_streamon(q, q->type);
if (ret)
goto err_reqbufs;
return ret;
err_reqbufs:
fileio->req.count = 0;
vb2_core_reqbufs(q, fileio->req.memory, &fileio->req.count);
err_kfree:
q->fileio = NULL;
kfree(fileio);
return ret;
}
