Controls can be exposed to userspace via a v4l-subdevX device, and userspace has to be able to subscribe to control events so that it is notified when the control changes value. If a control handler is set for the subdev then set the HAS_EVENTS flag automatically into v4l2_subdev_init_finalize() and use v4l2_ctrl_subdev_subscribe_event() and v4l2_event_subdev_unsubscribe() as default if subdev don't have .(un)subscribe control operations. Signed-off-by: Tommaso Merciai <tomm.merciai@xxxxxxxxx> --- Changes since v1: - Aligned event subscription with unsubscription as suggested by LPinchart, SAilus drivers/media/v4l2-core/v4l2-subdev.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c index 3a4ba08810d2..fad8fa1f63e8 100644 --- a/drivers/media/v4l2-core/v4l2-subdev.c +++ b/drivers/media/v4l2-core/v4l2-subdev.c @@ -691,10 +691,25 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg, return v4l2_event_dequeue(vfh, arg, file->f_flags & O_NONBLOCK); case VIDIOC_SUBSCRIBE_EVENT: - return v4l2_subdev_call(sd, core, subscribe_event, vfh, arg); + if (v4l2_subdev_has_op(sd, core, subscribe_event)) + return v4l2_subdev_call(sd, core, subscribe_event, + vfh, arg); + + if ((sd->flags & V4L2_SUBDEV_FL_HAS_EVENTS) && + vfh->ctrl_handler) + return v4l2_ctrl_subdev_subscribe_event(sd, vfh, arg); + + return -ENOIOCTLCMD; case VIDIOC_UNSUBSCRIBE_EVENT: - return v4l2_subdev_call(sd, core, unsubscribe_event, vfh, arg); + if (v4l2_subdev_has_op(sd, core, unsubscribe_event)) + return v4l2_subdev_call(sd, core, unsubscribe_event, + vfh, arg); + + if (sd->flags & V4L2_SUBDEV_FL_HAS_EVENTS) + return v4l2_event_subdev_unsubscribe(sd, vfh, arg); + + return -ENOIOCTLCMD; #ifdef CONFIG_VIDEO_ADV_DEBUG case VIDIOC_DBG_G_REGISTER: @@ -1641,6 +1656,9 @@ int __v4l2_subdev_init_finalize(struct v4l2_subdev *sd, const char *name, } } + if (sd->ctrl_handler) + sd->flags |= V4L2_SUBDEV_FL_HAS_EVENTS; + state = __v4l2_subdev_state_alloc(sd, name, key); if (IS_ERR(state)) return PTR_ERR(state); -- 2.34.1
