altos: add ao_time_ns API

[fw/altos] / src / stm / ao_timer.c

diff --git a/src/stm/ao_timer.c b/src/stm/ao_timer.c
index 9e9436cfa685dae451ae27ff59b8c9af6b32be1c..d00deffab2161b80e0333f6524567deefdb87052 100644 (file)
--- a/src/stm/ao_timer.c
+++ b/src/stm/ao_timer.c
@@ -36,6 +36,23 @@ ao_time(void)
 {
        return ao_tick_count;
 }
+
+uint64_t
+ao_time_ns(void)
+{
+       AO_TICK_TYPE    before, after;
+       uint32_t        cvr;
+
+       do {
+               before = ao_tick_count;
+               cvr = stm_systick.cvr;
+               after = ao_tick_count;
+       } while (before != after);
+
+       return (uint64_t) after * (1000000000ULL / AO_HERTZ) +
+               (uint64_t) cvr * (1000000000ULL / AO_SYSTICK);
+}
+
 #endif
 
 #if AO_DATA_ALL