A-Team_Digital_Solutions/android_kernel_motorola_sm6375
Watch
2
0
Fork
You've already forked android_kernel_motorola_sm6375
 0
mirror of https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git synced 2026-10-29 19:21:31 -04:00
Code Issues Projects Releases Packages Wiki Activity

[media] v4l2-event: Add v4l2_subscribed_event_ops

Browse source 
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: Hans de Goede <[email protected]>
Acked-by: Hans Verkuil <[email protected]>
Signed-off-by: Laurent Pinchart <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>
This commit is contained in:
Hans de Goede 2012-04-08 12:59:46 -03:00 • committed by Mauro Carvalho Chehab
commit c53c254933
8 changed files with 86 additions and 30 deletions
Download patch file Download diff file Expand all files Collapse all files

28
Documentation/video4linux/v4l2-framework.txt
View file

@ -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.