sys: xtimer: add xtimer_wakeup64

sys/include/xtimer.h

@@ -215,6 +215,18 @@ void xtimer_set_msg64(xtimer_t *timer, uint64_t offset, msg_t *msg, kernel_pid_t
  */
 void xtimer_set_wakeup(xtimer_t *timer, uint32_t offset, kernel_pid_t pid);
 
+/**
+ * @brief Set a timer that wakes up a thread, 64bit version
+ *
+ * This function sets a timer that will wake up a thread when the timer has
+ * expired.
+ *
+ * @param[in] timer         timer struct to work with
+ * @param[in] offset        microseconds from now
+ * @param[in] pid           pid of the thread that will be woken up
+ */
+void xtimer_set_wakeup64(xtimer_t *timer, uint64_t offset, kernel_pid_t pid);
+
 /**
  * @brief Set a timer to execute a callback at some time in the future
  *

sys/xtimer/xtimer.c

@@ -127,6 +127,14 @@ void xtimer_set_wakeup(xtimer_t *timer, uint32_t offset, kernel_pid_t pid)
     xtimer_set(timer, offset);
 }
 
+void xtimer_set_wakeup64(xtimer_t *timer, uint64_t offset, kernel_pid_t pid)
+{
+    timer->callback = _callback_wakeup;
+    timer->arg = (void*) ((intptr_t)pid);
+
+    _xtimer_set64(timer, offset, offset >> 32);
+}
+
 /**
  * see http://www.hackersdelight.org/magic.htm.
  * This is to avoid using long integer division functions