STM32 LOW_POWER_TIMER update : lp_ticker

Removed unnecessary part

Author: jeromecoutant

targets/TARGET_STM/lp_ticker.c

@@ -1,6 +1,6 @@
 /* mbed Microcontroller Library
  *******************************************************************************
- * Copyright (c) 2016, STMicroelectronics
+ * Copyright (c) 2017, STMicroelectronics
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,29 +31,18 @@
 
 #if DEVICE_LOWPOWERTIMER
 
-#include "ticker_api.h"
-#include "lp_ticker_api.h"
-#include "rtc_api.h"
 #include "rtc_api_hal.h"
 
-static uint8_t lp_ticker_inited = 0;
-
 void lp_ticker_init(void)
 {
-    if (lp_ticker_inited) return;
-    lp_ticker_inited = 1;
-
     rtc_init();
-    rtc_set_irq_handler((uint32_t) lp_ticker_irq_handler);
 }
 
 uint32_t lp_ticker_read(void)
 {
     uint32_t usecs = 0;
     time_t time = 0;
 
-    lp_ticker_init();
-
     do {
         time = rtc_read();
         usecs = rtc_read_subseconds();
@@ -82,7 +71,7 @@ void lp_ticker_disable_interrupt(void)
 
 void lp_ticker_clear_interrupt(void)
 {
-
+    NVIC_ClearPendingIRQ(RTC_WKUP_IRQn);
 }
 
-#endif
+#endif /* DEVICE_LOWPOWERTIMER */

targets/TARGET_STM/rtc_api_hal.h

@@ -33,19 +33,12 @@
 
 #include <stdint.h>
 #include "rtc_api.h"
+#include "ticker_api.h"
+#include "lp_ticker_api.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
-/*
- * Extend rtc_api.h
- */
-
-/** Set the given function as handler of wakeup timer event.
- *
- * @param handler    The function to set as handler
- */
-void rtc_set_irq_handler(uint32_t handler);
 
 /** Read the subsecond register.
  *