Commit ce727574 authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab

[media] v4l2-ctrls: simplify event subscription

Signed-off-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 6e239399
...@@ -1013,6 +1013,7 @@ static int handler_new_ref(struct v4l2_ctrl_handler *hdl, ...@@ -1013,6 +1013,7 @@ static int handler_new_ref(struct v4l2_ctrl_handler *hdl,
insertion is an O(1) operation. */ insertion is an O(1) operation. */
if (list_empty(&hdl->ctrl_refs) || id > node2id(hdl->ctrl_refs.prev)) { if (list_empty(&hdl->ctrl_refs) || id > node2id(hdl->ctrl_refs.prev)) {
list_add_tail(&new_ref->node, &hdl->ctrl_refs); list_add_tail(&new_ref->node, &hdl->ctrl_refs);
hdl->nr_of_refs++;
goto insert_in_hash; goto insert_in_hash;
} }
...@@ -2061,3 +2062,22 @@ void v4l2_ctrl_del_fh(struct v4l2_ctrl *ctrl, struct v4l2_fh *fh) ...@@ -2061,3 +2062,22 @@ void v4l2_ctrl_del_fh(struct v4l2_ctrl *ctrl, struct v4l2_fh *fh)
v4l2_ctrl_unlock(ctrl); v4l2_ctrl_unlock(ctrl);
} }
EXPORT_SYMBOL(v4l2_ctrl_del_fh); EXPORT_SYMBOL(v4l2_ctrl_del_fh);
int v4l2_ctrl_subscribe_fh(struct v4l2_fh *fh,
struct v4l2_event_subscription *sub, unsigned n)
{
struct v4l2_ctrl_handler *hdl = fh->ctrl_handler;
int ret = 0;
if (!fh->events)
ret = v4l2_event_init(fh);
if (!ret) {
if (hdl->nr_of_refs * 2 > n)
n = hdl->nr_of_refs * 2;
ret = v4l2_event_alloc(fh, n);
}
if (!ret)
ret = v4l2_event_subscribe(fh, sub);
return ret;
}
EXPORT_SYMBOL(v4l2_ctrl_subscribe_fh);
...@@ -169,6 +169,7 @@ struct v4l2_ctrl_ref { ...@@ -169,6 +169,7 @@ struct v4l2_ctrl_ref {
* control is needed multiple times, so this is a simple * control is needed multiple times, so this is a simple
* optimization. * optimization.
* @buckets: Buckets for the hashing. Allows for quick control lookup. * @buckets: Buckets for the hashing. Allows for quick control lookup.
* @nr_of_refs: Total number of control references in the list.
* @nr_of_buckets: Total number of buckets in the array. * @nr_of_buckets: Total number of buckets in the array.
* @error: The error code of the first failed control addition. * @error: The error code of the first failed control addition.
*/ */
...@@ -178,6 +179,7 @@ struct v4l2_ctrl_handler { ...@@ -178,6 +179,7 @@ struct v4l2_ctrl_handler {
struct list_head ctrl_refs; struct list_head ctrl_refs;
struct v4l2_ctrl_ref *cached; struct v4l2_ctrl_ref *cached;
struct v4l2_ctrl_ref **buckets; struct v4l2_ctrl_ref **buckets;
u16 nr_of_refs;
u16 nr_of_buckets; u16 nr_of_buckets;
int error; int error;
}; };
...@@ -494,11 +496,29 @@ s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl); ...@@ -494,11 +496,29 @@ s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);
*/ */
int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val); int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);
/* Internal helper functions that deal with control events. */
void v4l2_ctrl_add_fh(struct v4l2_ctrl_handler *hdl, void v4l2_ctrl_add_fh(struct v4l2_ctrl_handler *hdl,
struct v4l2_ctrl_fh *ctrl_fh, struct v4l2_ctrl_fh *ctrl_fh,
struct v4l2_event_subscription *sub); struct v4l2_event_subscription *sub);
void v4l2_ctrl_del_fh(struct v4l2_ctrl *ctrl, struct v4l2_fh *fh); void v4l2_ctrl_del_fh(struct v4l2_ctrl *ctrl, struct v4l2_fh *fh);
/** v4l2_ctrl_subscribe_fh() - Helper function that subscribes a control event.
* @fh: The file handler that subscribed the control event.
* @sub: The event to subscribe (type must be V4L2_EVENT_CTRL).
* @n: How many events should be allocated? (Passed to v4l2_event_alloc).
* Recommended to set to twice the number of controls plus whatever
* is needed for other events. This function will set n to
* max(n, 2 * fh->ctrl_handler->nr_of_refs).
*
* A helper function that initializes the fh for events, allocates the
* list of events and subscribes the control event.
*
* Typically called in the handler of VIDIOC_SUBSCRIBE_EVENT in the
* V4L2_EVENT_CTRL case.
*/
int v4l2_ctrl_subscribe_fh(struct v4l2_fh *fh,
struct v4l2_event_subscription *sub, unsigned n);
/* Helpers for ioctl_ops. If hdl == NULL then they will all return -EINVAL. */ /* Helpers for ioctl_ops. If hdl == NULL then they will all return -EINVAL. */
int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc); int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm); int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);
......
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