On Thursday, January 27, 2011 13:28:58 Laurent Pinchart wrote:
> From: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxxxxxxxxxxxxx>
>
> Provide v4l2_subdevs with v4l2_event support. Subdev drivers only need very
> little to support events.
>
> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: David Cohen <david.cohen@xxxxxxxxx>
> Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> ---
> Documentation/video4linux/v4l2-framework.txt | 18 ++++++
> drivers/media/video/v4l2-subdev.c | 75 +++++++++++++++++++++++++-
> include/media/v4l2-subdev.h | 10 ++++
> 3 files changed, 102 insertions(+), 1 deletions(-)
>
> diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt
> index f683f63..4db1def 100644
> --- a/Documentation/video4linux/v4l2-framework.txt
> +++ b/Documentation/video4linux/v4l2-framework.txt
> @@ -352,6 +352,24 @@ VIDIOC_TRY_EXT_CTRLS
> controls can be also be accessed through one (or several) V4L2 device
> nodes.
>
> +VIDIOC_DQEVENT
> +VIDIOC_SUBSCRIBE_EVENT
> +VIDIOC_UNSUBSCRIBE_EVENT
> +
> + The events ioctls are identical to the ones defined in V4L2. They
> + behave identically, with the only exception that they deal only with
> + events generated by the sub-device. Depending on the driver, those
> + events can also be reported by one (or several) V4L2 device nodes.
> +
> + Sub-device drivers that want to use events need to set the
> + V4L2_SUBDEV_USES_EVENTS v4l2_subdev::flags and initialize
> + v4l2_subdev::nevents to events queue depth before registering the
> + sub-device. After registration events can be queued as usual on the
> + v4l2_subdev::devnode device node.
> +
> + To properly support events, the poll() file operation is also
> + implemented.
> +
>
> I2C sub-device drivers
> ----------------------
> diff --git a/drivers/media/video/v4l2-subdev.c b/drivers/media/video/v4l2-subdev.c
> index fc57ce7..fbccefd 100644
> --- a/drivers/media/video/v4l2-subdev.c
> +++ b/drivers/media/video/v4l2-subdev.c
> @@ -20,27 +20,69 @@
> * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
> */
>
> -#include <linux/types.h>
> #include <linux/ioctl.h>
> +#include <linux/slab.h>
> +#include <linux/types.h>
> #include <linux/videodev2.h>
>
> #include <media/v4l2-ctrls.h>
> #include <media/v4l2-device.h>
> #include <media/v4l2-ioctl.h>
> +#include <media/v4l2-fh.h>
> +#include <media/v4l2-event.h>
>
> static int subdev_open(struct file *file)
> {
> struct video_device *vdev = video_devdata(file);
> struct v4l2_subdev *sd = vdev_to_v4l2_subdev(vdev);
> + struct v4l2_fh *vfh;
> + int ret;
>
> if (!sd->initialized)
> return -EAGAIN;
>
> + if (sd->flags & V4L2_SUBDEV_FL_HAS_EVENTS) {
> + vfh = kzalloc(sizeof(*vfh), GFP_KERNEL);
> + if (vfh == NULL)
> + return -ENOMEM;
> +
> + ret = v4l2_fh_init(vfh, vdev);
> + if (ret)
> + goto err;
> +
> + ret = v4l2_event_init(vfh);
> + if (ret)
> + goto err;
> +
> + ret = v4l2_event_alloc(vfh, sd->nevents);
> + if (ret)
> + goto err;
> +
> + v4l2_fh_add(vfh);
> + file->private_data = vfh;
> + }
> +
> return 0;
> +
> +err:
> + if (vfh != NULL) {
> + v4l2_fh_exit(vfh);
> + kfree(vfh);
> + }
> +
> + return ret;
> }
>
> static int subdev_close(struct file *file)
> {
> + struct v4l2_fh *vfh = file->private_data;
> +
> + if (vfh != NULL) {
> + v4l2_fh_del(vfh);
> + v4l2_fh_exit(vfh);
> + kfree(vfh);
> + }
> +
> return 0;
> }
>
> @@ -48,6 +90,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg)
> {
> struct video_device *vdev = video_devdata(file);
> struct v4l2_subdev *sd = vdev_to_v4l2_subdev(vdev);
> + struct v4l2_fh *fh = file->private_data;
>
> switch (cmd) {
> case VIDIOC_QUERYCTRL:
> @@ -71,6 +114,18 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg)
> case VIDIOC_TRY_EXT_CTRLS:
> return v4l2_subdev_try_ext_ctrls(sd, arg);
>
> + case VIDIOC_DQEVENT:
> + if (!(sd->flags & V4L2_SUBDEV_FL_HAS_EVENTS))
> + return -ENOIOCTLCMD;
> +
> + return v4l2_event_dequeue(fh, arg, file->f_flags & O_NONBLOCK);
> +
> + case VIDIOC_SUBSCRIBE_EVENT:
> + return v4l2_subdev_call(sd, core, subscribe_event, fh, arg);
> +
> + case VIDIOC_UNSUBSCRIBE_EVENT:
> + return v4l2_subdev_call(sd, core, unsubscribe_event, fh, arg);
> +
> default:
> return -ENOIOCTLCMD;
> }
> @@ -84,11 +139,29 @@ static long subdev_ioctl(struct file *file, unsigned int cmd,
> return __video_usercopy(file, cmd, arg, subdev_do_ioctl);
> }
>
> +static unsigned int subdev_poll(struct file *file, poll_table *wait)
> +{
> + struct video_device *vdev = video_devdata(file);
> + struct v4l2_subdev *sd = vdev_to_v4l2_subdev(vdev);
> + struct v4l2_fh *fh = file->private_data;
> +
> + if (!(sd->flags & V4L2_SUBDEV_FL_HAS_EVENTS))
> + return POLLERR;
> +
> + poll_wait(file, &fh->events->wait, wait);
> +
> + if (v4l2_event_pending(fh))
> + return POLLPRI;
> +
> + return 0;
> +}
> +
> const struct v4l2_file_operations v4l2_subdev_fops = {
> .owner = THIS_MODULE,
> .open = subdev_open,
> .unlocked_ioctl = subdev_ioctl,
> .release = subdev_close,
> + .poll = subdev_poll,
> };
>
> void v4l2_subdev_init(struct v4l2_subdev *sd, const struct v4l2_subdev_ops *ops)
> diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
> index 90022f5..68cbe48 100644
> --- a/include/media/v4l2-subdev.h
> +++ b/include/media/v4l2-subdev.h
> @@ -37,6 +37,8 @@
>
> struct v4l2_device;
> struct v4l2_ctrl_handler;
> +struct v4l2_event_subscription;
> +struct v4l2_fh;
> struct v4l2_subdev;
> struct tuner_setup;
>
> @@ -165,6 +167,10 @@ struct v4l2_subdev_core_ops {
> int (*s_power)(struct v4l2_subdev *sd, int on);
> int (*interrupt_service_routine)(struct v4l2_subdev *sd,
> u32 status, bool *handled);
> + int (*subscribe_event)(struct v4l2_subdev *sd, struct v4l2_fh *fh,
> + struct v4l2_event_subscription *sub);
> + int (*unsubscribe_event)(struct v4l2_subdev *sd, struct v4l2_fh *fh,
> + struct v4l2_event_subscription *sub);
> };
>
> /* s_mode: switch the tuner to a specific tuner mode. Replacement of s_radio.
> @@ -424,6 +430,8 @@ struct v4l2_subdev_ops {
> #define V4L2_SUBDEV_FL_IS_SPI (1U << 1)
> /* Set this flag if this subdev needs a device node. */
> #define V4L2_SUBDEV_FL_HAS_DEVNODE (1U << 2)
> +/* Set this flag if this subdev generates events. */
> +#define V4L2_SUBDEV_FL_HAS_EVENTS (1U << 3)
Do we need this flag...
>
> /* Each instance of a subdev driver should create this struct, either
> stand-alone or embedded in a larger struct.
> @@ -446,6 +454,8 @@ struct v4l2_subdev {
> /* subdev device node */
> struct video_device devnode;
> unsigned int initialized;
> + /* number of events to be allocated on open */
> + unsigned int nevents;
...when we have this field? We could just test whether nevents > 0.
> };
>
> #define vdev_to_v4l2_subdev(vdev) \
>
Regards,
Hans
--
Hans Verkuil - video4linux developer - sponsored by Cisco
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