some more doxygen work (include the notion of modules)
diff --git a/include/osmocom/core/timer.h b/include/osmocom/core/timer.h
index 326a0c8..8f8c826 100644
--- a/include/osmocom/core/timer.h
+++ b/include/osmocom/core/timer.h
@@ -18,6 +18,10 @@
  *
  */
 
+/*! \defgroup timer Osmocom timers
+ *  @{
+ */
+
 /*! \file timer.h
  *  \brief Osmocom timer handling routines
  */
@@ -61,38 +65,12 @@
  * timer management
  */
 
-/*! \brief add a new timer to the timer management
- *  \param[in] timer the timer that should be added
- */
 void osmo_timer_add(struct osmo_timer_list *timer);
 
-/*! \brief schedule a timer at a given future relative time
- *  \param[in] timer the to-be-added timer
- *  \param[in] seconds number of seconds from now
- *  \param[in] microseconds number of microseconds from now
- *
- * This function can be used to (re-)schedule a given timer at a
- * specified number of seconds+microseconds in the future.  It will
- * internally add it to the timer management data structures, thus
- * osmo_timer_add() is automatically called.
- */
 void osmo_timer_schedule(struct osmo_timer_list *timer, int seconds, int microseconds);
 
-/*! \brief delete a timer from timer management
- *  \param[in] timer the to-be-deleted timer
- *
- * This function can be used to delete a previously added/scheduled
- * timer from the timer management code.
- */
 void osmo_timer_del(struct osmo_timer_list *timer);
 
-/*! \brief check if given timer is still pending
- *  \param[in] timer the to-be-checked timer
- *  \return 1 if pending, 0 otherwise
- *
- * This function can be used to determine whether a given timer
- * has alredy expired (returns 0) or is still pending (returns 1)
- */
 int osmo_timer_pending(struct osmo_timer_list *timer);
 
 
@@ -104,4 +82,6 @@
 int osmo_timers_update(void);
 int osmo_timers_check(void);
 
+/*! }@ */
+
 #endif