Diff: targets/TARGET_STM/rtc_api.c

Revision:

189:f392fc9709a3

Parent:

188:bcfe06ba3d64

--- a/targets/TARGET_STM/rtc_api.c	Thu Nov 08 11:46:34 2018 +0000
+++ b/targets/TARGET_STM/rtc_api.c	Wed Feb 20 22:31:08 2019 +0000
@@ -93,6 +93,10 @@
     // Enable RTC
     __HAL_RCC_RTC_ENABLE();
 
+#if defined __HAL_RCC_RTCAPB_CLK_ENABLE /* part of STM32L4 */
+    __HAL_RCC_RTCAPB_CLK_ENABLE();
+#endif /* __HAL_RCC_RTCAPB_CLK_ENABLE */
+
     RtcHandle.Instance = RTC;
     RtcHandle.State = HAL_RTC_STATE_RESET;
 
@@ -105,6 +109,12 @@
     RtcHandle.Init.OutPut         = RTC_OUTPUT_DISABLE;
     RtcHandle.Init.OutPutPolarity = RTC_OUTPUT_POLARITY_HIGH;
     RtcHandle.Init.OutPutType     = RTC_OUTPUT_TYPE_OPENDRAIN;
+#if defined (RTC_OUTPUT_REMAP_NONE)
+    RtcHandle.Init.OutPutRemap    = RTC_OUTPUT_REMAP_NONE;
+#endif /* defined (RTC_OUTPUT_REMAP_NONE) */
+#if defined (RTC_OUTPUT_PULLUP_NONE)
+    RtcHandle.Init.OutPutPullUp   = RTC_OUTPUT_PULLUP_NONE;
+#endif /* defined (RTC_OUTPUT_PULLUP_NONE) */
 #endif /* TARGET_STM32F1 */
 
     if (HAL_RTC_Init(&RtcHandle) != HAL_OK) {
@@ -257,11 +267,11 @@
 
 int rtc_isenabled(void)
 {
-#if !(TARGET_STM32F1)
-    return ((RTC->ISR & RTC_ISR_INITS) ==  RTC_ISR_INITS);
-#else /* TARGET_STM32F1 */
+#if defined (RTC_FLAG_INITS) /* all STM32 except STM32F1 */
+    return LL_RTC_IsActiveFlag_INITS(RTC);
+#else /* RTC_FLAG_INITS */ /* TARGET_STM32F1 */
     return ((RTC->CRL & RTC_CRL_RSF) ==  RTC_CRL_RSF);
-#endif /* TARGET_STM32F1 */
+#endif /* RTC_FLAG_INITS */
 }
 
 
@@ -296,7 +306,9 @@
         }
     }
 
+#ifdef __HAL_RTC_WAKEUPTIMER_EXTI_CLEAR_FLAG
     __HAL_RTC_WAKEUPTIMER_EXTI_CLEAR_FLAG();
+#endif
 }
 
 uint32_t rtc_read_lp(void)
@@ -341,25 +353,60 @@
 
 void rtc_set_wake_up_timer(timestamp_t timestamp)
 {
+    /* RTC periodic auto wake up timer is used
+    *  This WakeUpTimer is loaded to an init value => WakeUpCounter
+    *  then timer starts counting down (even in low-power modes)
+    *  When it reaches 0, the WUTF flag is set in the RTC_ISR register
+    */
     uint32_t WakeUpCounter;
-    uint32_t current_lp_time;
+    uint32_t WakeUpClock = RTC_WAKEUPCLOCK_RTCCLK_DIV4;
 
-    current_lp_time = rtc_read_lp();
+    core_util_critical_section_enter();
 
+    /* MBED API gives the timestamp value to set
+    *  WakeUpCounter is then the delta between timestamp and the current tick (LPTICKER_counter)
+    *  If the current tick preceeds timestamp value, max U32 is added
+    */
+    uint32_t current_lp_time = rtc_read_lp();
     if (timestamp < current_lp_time) {
         WakeUpCounter = 0xFFFFFFFF - current_lp_time + timestamp;
     } else {
         WakeUpCounter = timestamp - current_lp_time;
     }
 
+    /* RTC WakeUpCounter is 16 bits
+    *  Corresponding time value depends on WakeUpClock
+    *  - RTC clock divided by 4  : max WakeUpCounter value is  8s (precision around 122 us)
+    *  - RTC clock divided by 8  : max WakeUpCounter value is 16s (precision around 244 us)
+    *  - RTC clock divided by 16 : max WakeUpCounter value is 32s (precision around 488 us)
+    *  - 1 Hz internal clock 16b : max WakeUpCounter value is 18h (precision 1 s)
+    *  - 1 Hz internal clock 17b : max WakeUpCounter value is 36h (precision 1 s)
+    */
     if (WakeUpCounter > 0xFFFF) {
-        WakeUpCounter = 0xFFFF;
+        WakeUpClock = RTC_WAKEUPCLOCK_RTCCLK_DIV8;
+        WakeUpCounter = WakeUpCounter / 2;
+
+        if (WakeUpCounter > 0xFFFF) {
+            WakeUpClock = RTC_WAKEUPCLOCK_RTCCLK_DIV16;
+            WakeUpCounter = WakeUpCounter / 2;
+
+            if (WakeUpCounter > 0xFFFF) {
+                /* Tick value needs to be translated in seconds : TICK * 16 (previous div16 value) / RTC clock (32768) */
+                WakeUpClock = RTC_WAKEUPCLOCK_CK_SPRE_16BITS;
+                WakeUpCounter = WakeUpCounter / 2048;
+
+                if (WakeUpCounter > 0xFFFF) {
+                    /* In this case 2^16 is added to the 16-bit counter value */
+                    WakeUpClock = RTC_WAKEUPCLOCK_CK_SPRE_17BITS;
+                    WakeUpCounter = WakeUpCounter - 0x10000;
+                }
+            }
+        }
     }
 
-    core_util_critical_section_enter();
     RtcHandle.Instance = RTC;
     HAL_RTCEx_DeactivateWakeUpTimer(&RtcHandle);
-    if (HAL_RTCEx_SetWakeUpTimer_IT(&RtcHandle, WakeUpCounter, RTC_WAKEUPCLOCK_RTCCLK_DIV4) != HAL_OK) {
+    if (HAL_RTCEx_SetWakeUpTimer_IT(&RtcHandle, WakeUpCounter, WakeUpClock) != HAL_OK) {
         error("rtc_set_wake_up_timer init error\n");
     }