[media] v4l2-ctrls: simplify event subscription
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
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@ -1013,6 +1013,7 @@ static int handler_new_ref(struct v4l2_ctrl_handler *hdl,
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insertion is an O(1) operation. */
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if (list_empty(&hdl->ctrl_refs) || id > node2id(hdl->ctrl_refs.prev)) {
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list_add_tail(&new_ref->node, &hdl->ctrl_refs);
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hdl->nr_of_refs++;
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goto insert_in_hash;
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}
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@ -2061,3 +2062,22 @@ void v4l2_ctrl_del_fh(struct v4l2_ctrl *ctrl, struct v4l2_fh *fh)
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v4l2_ctrl_unlock(ctrl);
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}
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EXPORT_SYMBOL(v4l2_ctrl_del_fh);
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int v4l2_ctrl_subscribe_fh(struct v4l2_fh *fh,
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struct v4l2_event_subscription *sub, unsigned n)
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{
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struct v4l2_ctrl_handler *hdl = fh->ctrl_handler;
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int ret = 0;
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if (!fh->events)
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ret = v4l2_event_init(fh);
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if (!ret) {
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if (hdl->nr_of_refs * 2 > n)
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n = hdl->nr_of_refs * 2;
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ret = v4l2_event_alloc(fh, n);
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}
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if (!ret)
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ret = v4l2_event_subscribe(fh, sub);
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return ret;
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}
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EXPORT_SYMBOL(v4l2_ctrl_subscribe_fh);
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@ -169,6 +169,7 @@ struct v4l2_ctrl_ref {
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* control is needed multiple times, so this is a simple
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* optimization.
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* @buckets: Buckets for the hashing. Allows for quick control lookup.
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* @nr_of_refs: Total number of control references in the list.
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* @nr_of_buckets: Total number of buckets in the array.
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* @error: The error code of the first failed control addition.
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*/
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@ -178,6 +179,7 @@ struct v4l2_ctrl_handler {
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struct list_head ctrl_refs;
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struct v4l2_ctrl_ref *cached;
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struct v4l2_ctrl_ref **buckets;
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u16 nr_of_refs;
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u16 nr_of_buckets;
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int error;
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};
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@ -494,11 +496,29 @@ s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);
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*/
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int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);
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/* Internal helper functions that deal with control events. */
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void v4l2_ctrl_add_fh(struct v4l2_ctrl_handler *hdl,
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struct v4l2_ctrl_fh *ctrl_fh,
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struct v4l2_event_subscription *sub);
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void v4l2_ctrl_del_fh(struct v4l2_ctrl *ctrl, struct v4l2_fh *fh);
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/** v4l2_ctrl_subscribe_fh() - Helper function that subscribes a control event.
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* @fh: The file handler that subscribed the control event.
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* @sub: The event to subscribe (type must be V4L2_EVENT_CTRL).
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* @n: How many events should be allocated? (Passed to v4l2_event_alloc).
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* Recommended to set to twice the number of controls plus whatever
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* is needed for other events. This function will set n to
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* max(n, 2 * fh->ctrl_handler->nr_of_refs).
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*
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* A helper function that initializes the fh for events, allocates the
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* list of events and subscribes the control event.
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*
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* Typically called in the handler of VIDIOC_SUBSCRIBE_EVENT in the
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* V4L2_EVENT_CTRL case.
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*/
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int v4l2_ctrl_subscribe_fh(struct v4l2_fh *fh,
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struct v4l2_event_subscription *sub, unsigned n);
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/* Helpers for ioctl_ops. If hdl == NULL then they will all return -EINVAL. */
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int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
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int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);
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