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[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 <t.stanislaws@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Tomasz Stanislawski 2012-06-14 11:32:24 -03:00 committed by Mauro Carvalho Chehab
parent 19b6ef5164
commit 83ae7c5a1b
4 changed files with 103 additions and 0 deletions
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13
drivers/media/v4l2-core/v4l2-mem2mem.c
View File

@ -368,6 +368,19 @@ int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
}
EXPORT_SYMBOL_GPL(v4l2_m2m_dqbuf);
/**
* v4l2_m2m_expbuf() - export a source or destination buffer, depending on
* the type
*/
int v4l2_m2m_expbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
struct v4l2_exportbuffer *eb)
{
struct vb2_queue *vq;
vq = v4l2_m2m_get_vq(m2m_ctx, eb->type);
return vb2_expbuf(vq, eb);
}
EXPORT_SYMBOL_GPL(v4l2_m2m_expbuf);
/**
* v4l2_m2m_streamon() - turn on streaming for a video queue
*/

83
drivers/media/v4l2-core/videobuf2-core.c
View File

@ -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)

3
include/media/v4l2-mem2mem.h
View File

@ -111,6 +111,9 @@ int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
struct v4l2_buffer *buf);
int v4l2_m2m_expbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
struct v4l2_exportbuffer *eb);
int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
enum v4l2_buf_type type);
int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,

4
include/media/videobuf2-core.h
View File

@ -81,6 +81,7 @@ struct vb2_fileio_data;
struct vb2_mem_ops {
void *(*alloc)(void *alloc_ctx, unsigned long size);
void (*put)(void *buf_priv);
struct dma_buf *(*get_dmabuf)(void *buf_priv);
void *(*get_userptr)(void *alloc_ctx, unsigned long vaddr,
unsigned long size, int write);
@ -363,6 +364,7 @@ int __must_check vb2_queue_init(struct vb2_queue *q);
void vb2_queue_release(struct vb2_queue *q);
int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b);
int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb);
int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking);
int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type);
@ -472,6 +474,8 @@ int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p);
int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p);
int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i);
int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i);
int vb2_ioctl_expbuf(struct file *file, void *priv,
struct v4l2_exportbuffer *p);
/* struct v4l2_file_operations helpers */