cpu: cortexm: adapt to periph/pm

cpu/cortexm_common/pm.c

@@ -1,6 +1,5 @@
 /*
- * Copyright (C) 2014-2015 Freie Universität Berlin
- *               2015 Kaspar Schleiser <kaspar@schleiser.de>
+ * Copyright (C) 2017 Kaspar Schleiser <kaspar@schleiser.de>
  *
  * This file is subject to the terms and conditions of the GNU Lesser
  * General Public License v2.1. See the file LICENSE in the top level
@@ -12,9 +11,8 @@
  * @{
  *
  * @file
- * @brief       Implementation of the kernels reboot interface
+ * @brief       common periph/pm functions
  *
- * @author      Hauke Petersen <hauke.petersen@fu-berlin.de>
  * @author      Kaspar Schleiser <kaspar@schleiser.de>
  *
  * @}
@@ -23,8 +21,19 @@
 #include <stdio.h>
 
 #include "cpu.h"
+#include "periph/pm.h"
 
-void reboot(void)
+#ifndef FEATURES_PERIPH_PM
+void pm_set_lowest(void)
+{
+    /* Executes a device DSB (Data Synchronization Barrier) */
+    __DSB();
+    /* Enter standby mode */
+    __WFI();
+}
+#endif
+
+void pm_reboot(void)
 {
     NVIC_SystemReset();
 }