[media] v4l: subdev: Events support

Provide v4l2_subdevs with v4l2_event support. Subdev drivers only need very
little to support events.

Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: David Cohen <dacohen@gmail.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 77 insertions, 1 deletions

diff --git a/drivers/media/video/v4l2-subdev.c b/drivers/media/video/v4l2-subdev.c
index da10430051c..0c67f5a278f 100644
--- a/drivers/media/video/v4l2-subdev.c
+++ b/drivers/media/video/v4l2-subdev.c
@@ -20,21 +20,66 @@
  * 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->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;
 }
 
@@ -42,6 +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:
@@ -65,6 +111,18 @@ 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;
 	}
@@ -78,11 +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)