add comments.

datalink814_ge/src/time_ctrl/time_ctrl.c

@@ -61,15 +61,35 @@ int32_t TimeCtrl_Init(TIMECTRL_INST **instPtr, TIMECTRL_CONFIG *config)
 	return SUCCESS;
 }
 
+/*****************************************************************************/
+/**
+ * @brief   Completely destroy time control instance.
+ *
+ * @param   instPtr a pointer to time controller instance
+ *
+ * @return  NONE
+ *
+ ******************************************************************************/
 void TimeCtrl_Destroy(TIMECTRL_INST *instPtr)
 {
 	free(instPtr);
 }
 
+/*****************************************************************************/
+/**
+ * @brief   Read time controller version register.
+ *
+ * @param   instPtr a pointer to time controller instance
+ *
+ * @return  timer controller version.
+ *
+ ******************************************************************************/
 uint32_t TimeCtrl_GetVersion(TIMECTRL_INST *instPtr)
 {
+	ASSERT(instPtr != NULL);
 	return TMC_Read(instPtr, VERSION_REG);
 }
+
 /*****************************************************************************/
 /**
  * @brief   Apply a reset process to time controller