k_delayed_work_submit_periodic() function

Submit a delayed work item to the system workqueue. This routine schedules work item @a work to be processed by the system workqueue after a delay of @a delay milliseconds. The routine initiates an asynchronous countdown for the work item and then returns to the caller. Only when the countdown completes is the work item actually submitted to the workqueue and becomes pending. Submitting a previously submitted delayed work item that is still counting down cancels the existing submission and restarts the countdown using the new delay. If the work item is currently pending on the workqueue's queue because the countdown has completed it is too late to resubmit the item, and resubmission fails without impacting the work item. If the work item has already been processed, or is currently being processed, its work is considered complete and the work item can be resubmitted. @warning Work items submitted to the system workqueue should avoid using handlers that block or yield since this may prevent the system workqueue from processing other work items in a timely manner.

Get time remaining before a delayed work gets scheduled. This routine computes the (approximate) time remaining before a delayed work gets executed. If the delayed work is not waiting to be scheduled, it returns zero.