From 83ae7c5a1b5b5cd4380ff70797e4c5dcfb61a70d Mon Sep 17 00:00:00 2001 From: Tomasz Stanislawski Date: Thu, 14 Jun 2012 11:32:24 -0300 Subject: [media] v4l: vb2: add buffer exporting via dmabuf This patch adds extension to videobuf2-core. It allow to export an mmap buffer as a DMABUF file descriptor. Signed-off-by: Tomasz Stanislawski Signed-off-by: Kyungmin Park Acked-by: Laurent Pinchart Acked-by: Hans Verkuil Tested-by: Mauro Carvalho Chehab Signed-off-by: Mauro Carvalho Chehab --- drivers/media/v4l2-core/videobuf2-core.c | 83 ++++++++++++++++++++++++++++++++ 1 file changed, 83 insertions(+) (limited to 'drivers/media/v4l2-core/videobuf2-core.c') diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c index 613dea16a304..9f81be23a81f 100644 --- a/drivers/media/v4l2-core/videobuf2-core.c +++ b/drivers/media/v4l2-core/videobuf2-core.c @@ -1750,6 +1750,79 @@ static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off, return -EINVAL; } +/** + * vb2_expbuf() - Export a buffer as a file descriptor + * @q: videobuf2 queue + * @eb: export buffer structure passed from userspace to vidioc_expbuf + * handler in driver + * + * The return values from this function are intended to be directly returned + * from vidioc_expbuf handler in driver. + */ +int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb) +{ + struct vb2_buffer *vb = NULL; + struct vb2_plane *vb_plane; + int ret; + struct dma_buf *dbuf; + + if (q->memory != V4L2_MEMORY_MMAP) { + dprintk(1, "Queue is not currently set up for mmap\n"); + return -EINVAL; + } + + if (!q->mem_ops->get_dmabuf) { + dprintk(1, "Queue does not support DMA buffer exporting\n"); + return -EINVAL; + } + + if (eb->flags & ~O_CLOEXEC) { + dprintk(1, "Queue does support only O_CLOEXEC flag\n"); + return -EINVAL; + } + + if (eb->type != q->type) { + dprintk(1, "qbuf: invalid buffer type\n"); + return -EINVAL; + } + + if (eb->index >= q->num_buffers) { + dprintk(1, "buffer index out of range\n"); + return -EINVAL; + } + + vb = q->bufs[eb->index]; + + if (eb->plane >= vb->num_planes) { + dprintk(1, "buffer plane out of range\n"); + return -EINVAL; + } + + vb_plane = &vb->planes[eb->plane]; + + dbuf = call_memop(q, get_dmabuf, vb_plane->mem_priv); + if (IS_ERR_OR_NULL(dbuf)) { + dprintk(1, "Failed to export buffer %d, plane %d\n", + eb->index, eb->plane); + return -EINVAL; + } + + ret = dma_buf_fd(dbuf, eb->flags); + if (ret < 0) { + dprintk(3, "buffer %d, plane %d failed to export (%d)\n", + eb->index, eb->plane, ret); + dma_buf_put(dbuf); + return ret; + } + + dprintk(3, "buffer %d, plane %d exported as %d descriptor\n", + eb->index, eb->plane, ret); + eb->fd = ret; + + return 0; +} +EXPORT_SYMBOL_GPL(vb2_expbuf); + /** * vb2_mmap() - map video buffers into application address space * @q: videobuf2 queue @@ -2456,6 +2529,16 @@ int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i) } EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff); +int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p) +{ + struct video_device *vdev = video_devdata(file); + + if (vb2_queue_is_busy(vdev, file)) + return -EBUSY; + return vb2_expbuf(vdev->queue, p); +} +EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf); + /* v4l2_file_operations helpers */ int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma) -- cgit v1.2.3-55-g7522