struct v4l2_ctrl

struct v4l2_ctrl_handler
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Name

struct v4l2_ctrl_handler — The control handler keeps track of all the

Synopsis

struct v4l2_ctrl_handler {
  struct mutex _lock;
  struct mutex * lock;
  struct list_head ctrls;
  struct list_head ctrl_refs;
  struct v4l2_ctrl_ref * cached;
  struct v4l2_ctrl_ref ** buckets;
  v4l2_ctrl_notify_fnc notify;
  void * notify_priv;
  u16 nr_of_buckets;
  int error;
};

Members

_lock: Default for “lock”.
lock: Lock to control access to this handler and its controls. May be replaced by the user right after init.
ctrls: The list of controls owned by this handler.
ctrl_refs: The list of control references.
cached: The last found control reference. It is common that the same control is needed multiple times, so this is a simple optimization.
buckets: Buckets for the hashing. Allows for quick control lookup.
notify: A notify callback that is called whenever the control changes value. Note that the handler's lock is held when the notify function is called!
notify_priv: Passed as argument to the v4l2_ctrl notify callback.
nr_of_buckets: Total number of buckets in the array.
error: The error code of the first failed control addition.

controls

both the controls owned by the handler and those inherited from other handlers.