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

drivers/media/video/v4l2-ctrls.c

+20 −0
Original line number Diff line number Diff line
@@ -1013,6 +1013,7 @@ static int handler_new_ref(struct v4l2_ctrl_handler *hdl, 
	   insertion is an O(1) operation. */

	if (list_empty(&hdl->ctrl_refs) || id > node2id(hdl->ctrl_refs.prev)) {

		list_add_tail(&new_ref->node, &hdl->ctrl_refs);

		hdl->nr_of_refs++;

		goto insert_in_hash;

	}
@@ -2061,3 +2062,22 @@ void v4l2_ctrl_del_fh(struct v4l2_ctrl *ctrl, struct v4l2_fh *fh) 
	v4l2_ctrl_unlock(ctrl);

}

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);

include/media/v4l2-ctrls.h

+20 −0
Original line number Diff line number Diff line
@@ -169,6 +169,7 @@ struct v4l2_ctrl_ref { 
  *		control is needed multiple times, so this is a simple

  *		optimization.

  * @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.

  * @error:	The error code of the first failed control addition.

  */
@@ -178,6 +179,7 @@ struct v4l2_ctrl_handler { 
	struct list_head ctrl_refs;

	struct v4l2_ctrl_ref *cached;

	struct v4l2_ctrl_ref **buckets;

	u16 nr_of_refs;

	u16 nr_of_buckets;

	int error;

};
@@ -494,11 +496,29 @@ s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl); 
  */

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,

		struct v4l2_ctrl_fh *ctrl_fh,

		struct v4l2_event_subscription *sub);

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. */

int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);

int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);