The poll callback function takes the following arguments: number of lines
(unsigned int), an array of file descriptors on which input events should
be monitored (struct gpiod_ctxless_event_poll_fd *), poll timeout
(const struct timespec *) and a pointer to user data (void *).
The callback should poll for input events on the set of descriptors and
return an appropriate value that can be interpreted by the event loop
routine.
@brief Simple event poll callback signature.
The poll callback function takes the following arguments: number of lines (unsigned int), an array of file descriptors on which input events should be monitored (struct gpiod_ctxless_event_poll_fd *), poll timeout (const struct timespec *) and a pointer to user data (void *).
The callback should poll for input events on the set of descriptors and return an appropriate value that can be interpreted by the event loop routine.