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.liakhovet...@gmx.de>
---
v9:
1. added the V4L2_BUF_FLAG_PREPARED videobuffer flag
2. removed "const" from the .vidioc_prepare_buf() method argument
drivers/media/video/v4l2-compat-ioctl32.c | 67 +++++++++++++++++++++++++---
drivers/media/video/v4l2-ioctl.c | 29 ++++++++++++
include/linux/videodev2.h | 18 ++++++++
include/media/v4l2-ioctl.h | 2 +
4 files changed, 108 insertions(+), 8 deletions(-)
diff --git a/drivers/media/video/v4l2-compat-ioctl32.c
b/drivers/media/video/v4l2-compat-ioctl32.c
index 61979b7..85758d2 100644
--- a/drivers/media/video/v4l2-compat-ioctl32.c
+++ b/drivers/media/video/v4l2-compat-ioctl32.c
@@ -159,11 +159,16 @@ struct v4l2_format32 {
} fmt;
};
-static int get_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32
__user *up)
+struct v4l2_create_buffers32 {
+ __u32 index; /* output: buffers
index...index + count - 1 have been created */
+ __u32 count;
+ enum v4l2_memory memory;
+ struct v4l2_format32 format; /* filled in by the user, plane
sizes calculated by the driver */
+ __u32 reserved[8];
+};
+
+static int __get_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32
__user *up)
{
- if (!access_ok(VERIFY_READ, up, sizeof(struct v4l2_format32)) ||
- get_user(kp->type, &up->type))
- return -EFAULT;
switch (kp->type) {
case V4L2_BUF_TYPE_VIDEO_CAPTURE:
case V4L2_BUF_TYPE_VIDEO_OUTPUT:
@@ -192,11 +197,24 @@ static int get_v4l2_format32(struct v4l2_format *kp,
struct v4l2_format32 __user
}
}
-static int put_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32
__user *up)
+static int get_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32
__user *up)
+{
+ if (!access_ok(VERIFY_READ, up, sizeof(struct v4l2_format32)) ||
+ get_user(kp->type, &up->type))
+ return -EFAULT;
+ return __get_v4l2_format32(kp, up);
+}
+
+static int get_v4l2_create32(struct v4l2_create_buffers *kp, struct
v4l2_create_buffers32 __user *up)
+{
+ if (!access_ok(VERIFY_READ, up, sizeof(struct v4l2_create_buffers32)) ||
+ copy_from_user(kp, up, offsetof(struct v4l2_create_buffers32,
format.fmt)))
+ return -EFAULT;
+ return __get_v4l2_format32(&kp->format, &up->format);
+}
+
+static int __put_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32
__user *up)
{
- if (!access_ok(VERIFY_WRITE, up, sizeof(struct v4l2_format32)) ||
- put_user(kp->type, &up->type))
- return -EFAULT;
switch (kp->type) {
case V4L2_BUF_TYPE_VIDEO_CAPTURE:
case V4L2_BUF_TYPE_VIDEO_OUTPUT:
@@ -225,6 +243,22 @@ static int put_v4l2_format32(struct v4l2_format *kp,
struct v4l2_format32 __user
}
}
+static int put_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32
__user *up)
+{
+ if (!access_ok(VERIFY_WRITE, up, sizeof(struct v4l2_format32)) ||
+ put_user(kp->type, &up->type))
+ return -EFAULT;
+ return __put_v4l2_format32(kp, up);
+}
+
+static int put_v4l2_create32(struct v4l2_create_buffers *kp, struct
v4l2_create_buffers32 __user *up)
+{
+ if (!access_ok(VERIFY_WRITE, up, sizeof(struct v4l2_create_buffers32))
||
+ copy_to_user(up, kp, offsetof(struct v4l2_create_buffers32,
format.fmt)))
+ return -EFAULT;
+ return __put_v4l2_format32(&kp->format, &up->format);
+}
+
struct v4l2_standard32 {
__u32 index;
__u32 id[2]; /* __u64 would get the alignment wrong */
@@ -702,6 +736,8 @@ static int put_v4l2_event32(struct v4l2_event *kp, struct
v4l2_event32 __user *u
#define VIDIOC_S_EXT_CTRLS32 _IOWR('V', 72, struct v4l2_ext_controls32)
#define VIDIOC_TRY_EXT_CTRLS32 _IOWR('V', 73, struct v4l2_ext_controls32)
#define VIDIOC_DQEVENT32 _IOR ('V', 89, struct v4l2_event32)
+#define VIDIOC_CREATE_BUFS32 _IOWR('V', 92, struct v4l2_create_buffers32)
+#define VIDIOC_PREPARE_BUF32 _IOW ('V', 93, struct v4l2_buffer32)
#define VIDIOC_OVERLAY32 _IOW ('V', 14, s32)
#define VIDIOC_STREAMON32 _IOW ('V', 18, s32)
@@ -721,6 +757,7 @@ static long do_video_ioctl(struct file *file, unsigned int
cmd, unsigned long ar
struct v4l2_standard v2s;
struct v4l2_ext_controls v2ecs;
struct v4l2_event v2ev;
+ struct v4l2_create_buffers v2crt;
unsigned long vx;
int vi;
} karg;
@@ -751,6 +788,8 @@ static long do_video_ioctl(struct file *file, unsigned int
cmd, unsigned long ar
case VIDIOC_S_INPUT32: cmd = VIDIOC_S_INPUT; break;
case VIDIOC_G_OUTPUT32: cmd = VIDIOC_G_OUTPUT; break;
case VIDIOC_S_OUTPUT32: cmd = VIDIOC_S_OUTPUT; break;
+ case VIDIOC_CREATE_BUFS32: cmd = VIDIOC_CREATE_BUFS; break;
+ case VIDIOC_PREPARE_BUF32: cmd = VIDIOC_PREPARE_BUF; break;
}
switch (cmd) {
@@ -775,6 +814,12 @@ static long do_video_ioctl(struct file *file, unsigned int
cmd, unsigned long ar
compatible_arg = 0;
break;
+ case VIDIOC_CREATE_BUFS:
+ err = get_v4l2_create32(&karg.v2crt, up);
+ compatible_arg = 0;
+ break;
+
+ case VIDIOC_PREPARE_BUF:
case VIDIOC_QUERYBUF:
case VIDIOC_QBUF:
case VIDIOC_DQBUF:
@@ -860,6 +905,10 @@ static long do_video_ioctl(struct file *file, unsigned int
cmd, unsigned long ar
err = put_v4l2_format32(&karg.v2f, up);
break;
+ case VIDIOC_CREATE_BUFS:
+ err = put_v4l2_create32(&karg.v2crt, up);
+ break;
+
case VIDIOC_QUERYBUF:
case VIDIOC_QBUF:
case VIDIOC_DQBUF:
@@ -959,6 +1008,8 @@ long v4l2_compat_ioctl32(struct file *file, unsigned int
cmd, unsigned long arg)
case VIDIOC_DQEVENT32:
case VIDIOC_SUBSCRIBE_EVENT:
case VIDIOC_UNSUBSCRIBE_EVENT:
+ case VIDIOC_CREATE_BUFS32:
+ case VIDIOC_PREPARE_BUF32:
ret = do_video_ioctl(file, cmd, arg);
break;
diff --git a/drivers/media/video/v4l2-ioctl.c b/drivers/media/video/v4l2-ioctl.c
index 21c49dc..3c2295b 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)
@@ -2096,6 +2098,33 @@ 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;
+ 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 = ops->vidioc_prepare_buf(file, fh, b);
+
+ dbgarg(cmd, "index=%d", b->index);
+ break;
+ }
default:
if (!ops->vidioc_default)
break;
diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
index 9d14523..a552946 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
@@ -2099,6 +2103,15 @@ 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
*
@@ -2189,6 +2202,11 @@ 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 _IOW('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 dd9f1e7..4d1c74a 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,
--
1.7.2.5
--
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