Commit c53c2549 authored by Hans de Goede's avatar Hans de Goede Committed by Mauro Carvalho Chehab

[media] v4l2-event: Add v4l2_subscribed_event_ops

Just like with ctrl events, drivers may want to get called back on
listener add / remove for other event types too. Rather then special
casing all of this in subscribe / unsubscribe event it is better to
use ops for this.
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Acked-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent a22d85fe
......@@ -945,21 +945,35 @@ fast.
Useful functions:
- v4l2_event_queue()
void v4l2_event_queue(struct video_device *vdev, const struct v4l2_event *ev)
Queue events to video device. The driver's only responsibility is to fill
in the type and the data fields. The other fields will be filled in by
V4L2.
- v4l2_event_subscribe()
int v4l2_event_subscribe(struct v4l2_fh *fh,
struct v4l2_event_subscription *sub, unsigned elems,
const struct v4l2_subscribed_event_ops *ops)
The video_device->ioctl_ops->vidioc_subscribe_event must check the driver
is able to produce events with specified event id. Then it calls
v4l2_event_subscribe() to subscribe the event. The last argument is the
size of the event queue for this event. If it is 0, then the framework
will fill in a default value (this depends on the event type).
v4l2_event_subscribe() to subscribe the event.
- v4l2_event_unsubscribe()
The elems argument is the size of the event queue for this event. If it is 0,
then the framework will fill in a default value (this depends on the event
type).
The ops argument allows the driver to specify a number of callbacks:
* add: called when a new listener gets added (subscribing to the same
event twice will only cause this callback to get called once)
* del: called when a listener stops listening
* replace: replace event 'old' with event 'new'.
* merge: merge event 'old' into event 'new'.
All 4 callbacks are optional, if you don't want to specify any callbacks
the ops argument itself maybe NULL.
int v4l2_event_unsubscribe(struct v4l2_fh *fh,
struct v4l2_event_subscription *sub)
vidioc_unsubscribe_event in struct v4l2_ioctl_ops. A driver may use
v4l2_event_unsubscribe() directly unless it wants to be involved in
......@@ -968,7 +982,7 @@ Useful functions:
The special type V4L2_EVENT_ALL may be used to unsubscribe all events. The
drivers may want to handle this in a special way.
- v4l2_event_pending()
int v4l2_event_pending(struct v4l2_fh *fh)
Returns the number of pending events. Useful when implementing poll.
......
......@@ -1469,7 +1469,7 @@ static int ivtv_subscribe_event(struct v4l2_fh *fh, struct v4l2_event_subscripti
case V4L2_EVENT_VSYNC:
case V4L2_EVENT_EOS:
case V4L2_EVENT_CTRL:
return v4l2_event_subscribe(fh, sub, 0);
return v4l2_event_subscribe(fh, sub, 0, NULL);
default:
return -EINVAL;
}
......
......@@ -1703,7 +1703,7 @@ static int ccdc_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
if (sub->id != 0)
return -EINVAL;
return v4l2_event_subscribe(fh, sub, OMAP3ISP_CCDC_NEVENTS);
return v4l2_event_subscribe(fh, sub, OMAP3ISP_CCDC_NEVENTS, NULL);
}
static int ccdc_unsubscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
......
......@@ -1032,7 +1032,7 @@ int omap3isp_stat_subscribe_event(struct v4l2_subdev *subdev,
if (sub->type != stat->event_type)
return -EINVAL;
return v4l2_event_subscribe(fh, sub, STAT_NEVENTS);
return v4l2_event_subscribe(fh, sub, STAT_NEVENTS, NULL);
}
int omap3isp_stat_unsubscribe_event(struct v4l2_subdev *subdev,
......
......@@ -2468,7 +2468,7 @@ int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
struct v4l2_event_subscription *sub)
{
if (sub->type == V4L2_EVENT_CTRL)
return v4l2_event_subscribe(fh, sub, 0);
return v4l2_event_subscribe(fh, sub, 0, NULL);
return -EINVAL;
}
EXPORT_SYMBOL(v4l2_ctrl_subscribe_event);
......
......@@ -120,6 +120,14 @@ static void __v4l2_event_queue_fh(struct v4l2_fh *fh, const struct v4l2_event *e
if (sev == NULL)
return;
/*
* If the event has been added to the fh->subscribed list, but its
* add op has not completed yet elems will be 0, treat this as
* not being subscribed.
*/
if (!sev->elems)
return;
/* Increase event sequence number on fh. */
fh->sequence++;
......@@ -132,14 +140,14 @@ static void __v4l2_event_queue_fh(struct v4l2_fh *fh, const struct v4l2_event *e
sev->first = sev_pos(sev, 1);
fh->navailable--;
if (sev->elems == 1) {
if (sev->replace) {
sev->replace(&kev->event, ev);
if (sev->ops && sev->ops->replace) {
sev->ops->replace(&kev->event, ev);
copy_payload = false;
}
} else if (sev->merge) {
} else if (sev->ops && sev->ops->merge) {
struct v4l2_kevent *second_oldest =
sev->events + sev_pos(sev, 0);
sev->merge(&kev->event, &second_oldest->event);
sev->ops->merge(&kev->event, &second_oldest->event);
}
}
......@@ -208,8 +216,14 @@ static void ctrls_merge(const struct v4l2_event *old, struct v4l2_event *new)
new->u.ctrl.changes |= old->u.ctrl.changes;
}
static const struct v4l2_subscribed_event_ops ctrl_ops = {
.replace = ctrls_replace,
.merge = ctrls_merge,
};
int v4l2_event_subscribe(struct v4l2_fh *fh,
struct v4l2_event_subscription *sub, unsigned elems)
struct v4l2_event_subscription *sub, unsigned elems,
const struct v4l2_subscribed_event_ops *ops)
{
struct v4l2_subscribed_event *sev, *found_ev;
struct v4l2_ctrl *ctrl = NULL;
......@@ -236,10 +250,9 @@ int v4l2_event_subscribe(struct v4l2_fh *fh,
sev->id = sub->id;
sev->flags = sub->flags;
sev->fh = fh;
sev->elems = elems;
sev->ops = ops;
if (ctrl) {
sev->replace = ctrls_replace;
sev->merge = ctrls_merge;
sev->ops = &ctrl_ops;
}
spin_lock_irqsave(&fh->vdev->fh_lock, flags);
......@@ -248,12 +261,27 @@ int v4l2_event_subscribe(struct v4l2_fh *fh,
list_add(&sev->list, &fh->subscribed);
spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
/* v4l2_ctrl_add_event uses a mutex, so do this outside the spin lock */
if (found_ev)
if (found_ev) {
kfree(sev);
else if (ctrl)
return 0; /* Already listening */
}
if (sev->ops && sev->ops->add) {
int ret = sev->ops->add(sev);
if (ret) {
sev->ops = NULL;
v4l2_event_unsubscribe(fh, sub);
return ret;
}
}
/* v4l2_ctrl_add_event uses a mutex, so do this outside the spin lock */
if (ctrl)
v4l2_ctrl_add_event(ctrl, sev);
/* Mark as ready for use */
sev->elems = elems;
return 0;
}
EXPORT_SYMBOL_GPL(v4l2_event_subscribe);
......@@ -306,6 +334,10 @@ int v4l2_event_unsubscribe(struct v4l2_fh *fh,
}
spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
if (sev && sev->ops && sev->ops->del)
sev->ops->del(sev);
if (sev && sev->type == V4L2_EVENT_CTRL) {
struct v4l2_ctrl *ctrl = v4l2_ctrl_find(fh->ctrl_handler, sev->id);
......
......@@ -296,7 +296,7 @@ uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
if (sub->type < UVC_EVENT_FIRST || sub->type > UVC_EVENT_LAST)
return -EINVAL;
return v4l2_event_subscribe(&handle->vfh, arg, 2);
return v4l2_event_subscribe(&handle->vfh, arg, 2, NULL);
}
case VIDIOC_UNSUBSCRIBE_EVENT:
......
......@@ -78,6 +78,19 @@ struct v4l2_kevent {
struct v4l2_event event;
};
/** struct v4l2_subscribed_event_ops - Subscribed event operations.
* @add: Optional callback, called when a new listener is added
* @del: Optional callback, called when a listener stops listening
* @replace: Optional callback that can replace event 'old' with event 'new'.
* @merge: Optional callback that can merge event 'old' into event 'new'.
*/
struct v4l2_subscribed_event_ops {
int (*add)(struct v4l2_subscribed_event *sev);
void (*del)(struct v4l2_subscribed_event *sev);
void (*replace)(struct v4l2_event *old, const struct v4l2_event *new);
void (*merge)(const struct v4l2_event *old, struct v4l2_event *new);
};
/** struct v4l2_subscribed_event - Internal struct representing a subscribed event.
* @list: List node for the v4l2_fh->subscribed list.
* @type: Event type.
......@@ -85,8 +98,7 @@ struct v4l2_kevent {
* @flags: Copy of v4l2_event_subscription->flags.
* @fh: Filehandle that subscribed to this event.
* @node: List node that hooks into the object's event list (if there is one).
* @replace: Optional callback that can replace event 'old' with event 'new'.
* @merge: Optional callback that can merge event 'old' into event 'new'.
* @ops: v4l2_subscribed_event_ops
* @elems: The number of elements in the events array.
* @first: The index of the events containing the oldest available event.
* @in_use: The number of queued events.
......@@ -99,10 +111,7 @@ struct v4l2_subscribed_event {
u32 flags;
struct v4l2_fh *fh;
struct list_head node;
void (*replace)(struct v4l2_event *old,
const struct v4l2_event *new);
void (*merge)(const struct v4l2_event *old,
struct v4l2_event *new);
const struct v4l2_subscribed_event_ops *ops;
unsigned elems;
unsigned first;
unsigned in_use;
......@@ -115,7 +124,8 @@ void v4l2_event_queue(struct video_device *vdev, const struct v4l2_event *ev);
void v4l2_event_queue_fh(struct v4l2_fh *fh, const struct v4l2_event *ev);
int v4l2_event_pending(struct v4l2_fh *fh);
int v4l2_event_subscribe(struct v4l2_fh *fh,
struct v4l2_event_subscription *sub, unsigned elems);
struct v4l2_event_subscription *sub, unsigned elems,
const struct v4l2_subscribed_event_ops *ops);
int v4l2_event_unsubscribe(struct v4l2_fh *fh,
struct v4l2_event_subscription *sub);
void v4l2_event_unsubscribe_all(struct v4l2_fh *fh);
......
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