On Monday 12 July 2010 17:25:52 Laurent Pinchart wrote:
> From: Sakari Ailus <sakari.ai...@maxwell.research.nokia.com>
> 
> Provide v4l2_subdevs with v4l2_event support. Subdev drivers only need very
> little to support events.
> 
> Signed-off-by: Sakari Ailus <sakari.ai...@maxwell.research.nokia.com>
> Signed-off-by: David Cohen <david.co...@nokia.com>
> Signed-off-by: Laurent Pinchart <laurent.pinch...@ideasonboard.com>

Acked-by: Hans Verkuil <hverk...@xs4all.nl>

> ---
>  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 9c3f33c..89bd881 100644
> --- a/Documentation/video4linux/v4l2-framework.txt
> +++ b/Documentation/video4linux/v4l2-framework.txt
> @@ -347,6 +347,24 @@ 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 ea3941a..b063195 100644
> --- a/drivers/media/video/v4l2-subdev.c
> +++ b/drivers/media/video/v4l2-subdev.c
> @@ -18,26 +18,68 @@
>   *  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-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;
>  }
>  
> @@ -45,6 +87,7 @@ 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:
> @@ -68,6 +111,18 @@ static long subdev_do_ioctl(struct file *file, unsigned 
> int cmd, void *arg)
>       case VIDIOC_TRY_EXT_CTRLS:
>               return v4l2_subdev_call(sd, core, try_ext_ctrls, 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;
>       }
> @@ -81,11 +136,29 @@ 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 9ee45c8..55a8c93 100644
> --- a/include/media/v4l2-subdev.h
> +++ b/include/media/v4l2-subdev.h
> @@ -36,6 +36,8 @@
>  #define V4L2_SUBDEV_IR_TX_FIFO_SERVICE_REQ   0x00000001
>  
>  struct v4l2_device;
> +struct v4l2_event_subscription;
> +struct v4l2_fh;
>  struct v4l2_subdev;
>  struct tuner_setup;
>  
> @@ -134,6 +136,10 @@ struct v4l2_subdev_core_ops {
>       int (*s_register)(struct v4l2_subdev *sd, struct v4l2_dbg_register 
> *reg);
>  #endif
>       int (*s_power)(struct v4l2_subdev *sd, int on);
> +     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.
> @@ -408,6 +414,8 @@ 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)
>  
>  /* Each instance of a subdev driver should create this struct, either
>     stand-alone or embedded in a larger struct.
> @@ -427,6 +435,8 @@ struct v4l2_subdev {
>       /* subdev device node */
>       struct video_device devnode;
>       unsigned int initialized;
> +     /* number of events to be allocated on open */
> +     unsigned int nevents;
>  };
>  
>  #define vdev_to_v4l2_subdev(vdev) \
> 

-- 
Hans Verkuil - video4linux developer - sponsored by TANDBERG, part of Cisco
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