On Wednesday 10 February 2010 15:58:06 Sakari Ailus wrote:
> Add support for event handling to do_ioctl.
>
> Signed-off-by: Sakari Ailus <[email protected]>
> ---
> drivers/media/video/Makefile | 2 +-
> drivers/media/video/v4l2-ioctl.c | 49
> ++++++++++++++++++++++++++++++++++++++
> include/media/v4l2-ioctl.h | 5 ++++
> 3 files changed, 55 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
> index b888ad1..68253d6 100644
> --- a/drivers/media/video/Makefile
> +++ b/drivers/media/video/Makefile
> @@ -11,7 +11,7 @@ stkwebcam-objs := stk-webcam.o stk-sensor.o
> omap2cam-objs := omap24xxcam.o omap24xxcam-dma.o
>
> videodev-objs := v4l2-dev.o v4l2-ioctl.o v4l2-device.o
> v4l2-subdev.o \
> - v4l2-fh.o
> + v4l2-fh.o v4l2-event.o
>
> # V4L2 core modules
>
> diff --git a/drivers/media/video/v4l2-ioctl.c
> b/drivers/media/video/v4l2-ioctl.c
> index bfc4696..e0b9401 100644
> --- a/drivers/media/video/v4l2-ioctl.c
> +++ b/drivers/media/video/v4l2-ioctl.c
> @@ -25,6 +25,7 @@
> #endif
> #include <media/v4l2-common.h>
> #include <media/v4l2-ioctl.h>
> +#include <media/v4l2-event.h>
> #include <media/v4l2-chip-ident.h>
>
> #define dbgarg(cmd, fmt, arg...) \
> @@ -1797,7 +1798,55 @@ static long __video_do_ioctl(struct file *file,
> }
> break;
> }
> + case VIDIOC_DQEVENT:
> + {
> + struct v4l2_event *ev = arg;
> +
> + if (!ops->vidioc_subscribe_event)
> + break;
> +
> + ret = v4l2_event_dequeue(fh, ev);
> + if (ret < 0) {
> + dbgarg(cmd, "no pending events?");
> + break;
> + }
> + dbgarg(cmd,
> + "count=%d, type=0x%8.8x, sequence=%d, "
> + "timestamp=%lu.%9.9lu ",
> + ev->count, ev->type, ev->sequence,
> + ev->timestamp.tv_sec, ev->timestamp.tv_nsec);
> + break;
> + }
> + case VIDIOC_SUBSCRIBE_EVENT:
> + {
> + struct v4l2_event_subscription *sub = arg;
>
> + if (!ops->vidioc_subscribe_event)
> + break;
I know I said that we could use this test to determine if fh is of type
v4l2_fh, but that only works in this specific case, but not in the general
case. For example, I want to add support for the prio ioctls to v4l2_fh, and
then I probably have no vidioc_subscribe_event set since few drivers will
need that.
Instead I suggest that we add a new flag to v4l2-dev.h:
V4L2_FL_USES_V4L2_FH (1)
The v4l2_fh_add() function can then set this flag.
> +
> + ret = ops->vidioc_subscribe_event(fh, sub);
> + if (ret < 0) {
> + dbgarg(cmd, "failed, ret=%ld", ret);
> + break;
> + }
> + dbgarg(cmd, "type=0x%8.8x", sub->type);
> + break;
> + }
> + case VIDIOC_UNSUBSCRIBE_EVENT:
> + {
> + struct v4l2_event_subscription *sub = arg;
> +
> + if (!ops->vidioc_subscribe_event)
> + break;
> +
> + ret = v4l2_event_unsubscribe(fh, sub);
We should add an unsubscribe op as well. One reason is to add EVENT_ALL
support (see my comments in patch 7/7), the other is that in some cases
drivers might need to take some special action in response to subscribing
an event. And a driver needs a way to undo that when unsubscribing.
Regards,
Hans
> + if (ret < 0) {
> + dbgarg(cmd, "failed, ret=%ld", ret);
> + break;
> + }
> + dbgarg(cmd, "type=0x%8.8x", sub->type);
> + break;
> + }
> default:
> {
> if (!ops->vidioc_default)
> diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h
> index 7a4529d..ed3fff5 100644
> --- a/include/media/v4l2-ioctl.h
> +++ b/include/media/v4l2-ioctl.h
> @@ -21,6 +21,8 @@
> #include <linux/videodev2.h>
> #endif
>
> +struct v4l2_fh;
> +
> struct v4l2_ioctl_ops {
> /* ioctl callbacks */
>
> @@ -239,6 +241,9 @@ struct v4l2_ioctl_ops {
> int (*vidioc_enum_frameintervals) (struct file *file, void *fh,
> struct v4l2_frmivalenum *fival);
>
> + int (*vidioc_subscribe_event) (struct v4l2_fh *fh,
> + struct v4l2_event_subscription *sub);
> +
> /* For other private ioctls */
> long (*vidioc_default) (struct file *file, void *fh,
> int cmd, void *arg);
>
--
Hans Verkuil - video4linux developer - sponsored by TANDBERG
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