[media] V4L: add two new ioctl()s for multi-size videobuffer management

A possibility to preallocate and initialise buffers of different sizes
in V4L2 is required for an efficient implementation of a snapshot
mode. This patch adds two new ioctl()s: VIDIOC_CREATE_BUFS and
VIDIOC_PREPARE_BUF and defines respective data structures.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 36 insertions, 0 deletions

diff --git a/drivers/media/video/v4l2-ioctl.c b/drivers/media/video/v4l2-ioctl.c
index 24fd43322150..e1da8fc9dd2f 100644
--- a/drivers/media/video/v4l2-ioctl.c
+++ b/drivers/media/video/v4l2-ioctl.c
@@ -273,6 +273,8 @@ static const char *v4l2_ioctls[] = {
         [_IOC_NR(VIDIOC_DQEVENT)]          = "VIDIOC_DQEVENT",
         [_IOC_NR(VIDIOC_SUBSCRIBE_EVENT)]  = "VIDIOC_SUBSCRIBE_EVENT",
         [_IOC_NR(VIDIOC_UNSUBSCRIBE_EVENT)] = "VIDIOC_UNSUBSCRIBE_EVENT",
+        [_IOC_NR(VIDIOC_CREATE_BUFS)]      = "VIDIOC_CREATE_BUFS",
+        [_IOC_NR(VIDIOC_PREPARE_BUF)]      = "VIDIOC_PREPARE_BUF",
 };
 #define V4L2_IOCTLS ARRAY_SIZE(v4l2_ioctls)
 
@@ -2104,6 +2106,40 @@ static long __video_do_ioctl(struct file *file,
                 dbgarg(cmd, "type=0x%8.8x", sub->type);
                 break;
         }
+        case VIDIOC_CREATE_BUFS:
+        {
+                struct v4l2_create_buffers *create = arg;
+
+                if (!ops->vidioc_create_bufs)
+                        break;
+                if (ret_prio) {
+                        ret = ret_prio;
+                        break;
+                }
+                ret = check_fmt(ops, create->format.type);
+                if (ret)
+                        break;
+
+                ret = ops->vidioc_create_bufs(file, fh, create);
+
+                dbgarg(cmd, "count=%d @ %d\n", create->count, create->index);
+                break;
+        }
+        case VIDIOC_PREPARE_BUF:
+        {
+                struct v4l2_buffer *b = arg;
+
+                if (!ops->vidioc_prepare_buf)
+                        break;
+                ret = check_fmt(ops, b->type);
+                if (ret)
+                        break;
+
+                ret = ops->vidioc_prepare_buf(file, fh, b);
+
+                dbgarg(cmd, "index=%d", b->index);
+                break;
+        }
         default:
                 if (!ops->vidioc_default)
                         break;