in clients/pps-ktimer.c [28:38]
static void pps_ktimer_event(struct timer_list *unused)
{
struct pps_event_time ts;
/* First of all we get the time stamp... */
pps_get_ts(&ts);
pps_event(pps, &ts, PPS_CAPTUREASSERT, NULL);
mod_timer(&ktimer, jiffies + HZ);
}