[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>

2 files changed, 20 insertions, 0 deletions

diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
index 225560c1a10f..cd512f07beed 100644
--- a/include/linux/videodev2.h
+++ b/include/linux/videodev2.h
@@ -653,6 +653,10 @@ struct v4l2_buffer {
 #define V4L2_BUF_FLAG_ERROR     0x0040
 #define V4L2_BUF_FLAG_TIMECODE  0x0100  /* timecode field is valid */
 #define V4L2_BUF_FLAG_INPUT     0x0200  /* input field is valid */
+#define V4L2_BUF_FLAG_PREPARED  0x0400  /* Buffer is prepared for queuing */
+/* Cache handling flags */
+#define V4L2_BUF_FLAG_NO_CACHE_INVALIDATE       0x0800
+#define V4L2_BUF_FLAG_NO_CACHE_CLEAN            0x1000
 
 /*
  *      O V E R L A Y   P R E V I E W
@@ -2138,6 +2142,15 @@ struct v4l2_dbg_chip_ident {
         __u32 revision;    /* chip revision, chip specific */
 } __attribute__ ((packed));
 
+/* VIDIOC_CREATE_BUFS */
+struct v4l2_create_buffers {
+        __u32                   index;          /* output: buffers index...index + count - 1 have been created */
+        __u32                   count;
+        enum v4l2_memory        memory;
+        struct v4l2_format      format;         /* "type" is used always, the rest if sizeimage == 0 */
+        __u32                   reserved[8];
+};
+
 /*
  *      I O C T L   C O D E S   F O R   V I D E O   D E V I C E S
  *
@@ -2228,6 +2241,11 @@ struct v4l2_dbg_chip_ident {
 #define VIDIOC_SUBSCRIBE_EVENT   _IOW('V', 90, struct v4l2_event_subscription)
 #define VIDIOC_UNSUBSCRIBE_EVENT _IOW('V', 91, struct v4l2_event_subscription)
 
+/* Experimental, the below two ioctls may change over the next couple of kernel
+   versions */
+#define VIDIOC_CREATE_BUFS      _IOWR('V', 92, struct v4l2_create_buffers)
+#define VIDIOC_PREPARE_BUF      _IOWR('V', 93, struct v4l2_buffer)
+
 /* Reminder: when adding new ioctls please add support for them to
    drivers/media/video/v4l2-compat-ioctl32.c as well! */
 
diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h
index dd9f1e7b8ff7..4d1c74ad4c84 100644
--- a/include/media/v4l2-ioctl.h
+++ b/include/media/v4l2-ioctl.h
@@ -122,6 +122,8 @@ struct v4l2_ioctl_ops {
         int (*vidioc_qbuf)    (struct file *file, void *fh, struct v4l2_buffer *b);
         int (*vidioc_dqbuf)   (struct file *file, void *fh, struct v4l2_buffer *b);
 
+        int (*vidioc_create_bufs)(struct file *file, void *fh, struct v4l2_create_buffers *b);
+        int (*vidioc_prepare_buf)(struct file *file, void *fh, struct v4l2_buffer *b);
 
         int (*vidioc_overlay) (struct file *file, void *fh, unsigned int i);
         int (*vidioc_g_fbuf)   (struct file *file, void *fh,