stm32/rtc: Add RTC support for H7 MCUs.

ports/stm32/rtc.c

@@ -223,12 +223,16 @@ STATIC HAL_StatusTypeDef PYB_RCC_OscConfig(RCC_OscInitTypeDef  *RCC_OscInitStruc
 
     /*------------------------------ LSE Configuration -------------------------*/
     if ((RCC_OscInitStruct->OscillatorType & RCC_OSCILLATORTYPE_LSE) == RCC_OSCILLATORTYPE_LSE) {
+        #if !defined(STM32H7)
         // Enable Power Clock
         __HAL_RCC_PWR_CLK_ENABLE();
+        #endif
+
+        // Enable access to the backup domain
         HAL_PWR_EnableBkUpAccess();
         uint32_t tickstart = HAL_GetTick();
 
-        #if defined(MCU_SERIES_F7) || defined(MCU_SERIES_L4)
+        #if defined(MCU_SERIES_F7) || defined(MCU_SERIES_L4) || defined(STM32H7)
         //__HAL_RCC_PWR_CLK_ENABLE();
         // Enable write access to Backup domain
         //PWR->CR1 |= PWR_CR1_DBP;
@@ -298,7 +302,7 @@ STATIC HAL_StatusTypeDef PYB_RTC_Init(RTC_HandleTypeDef *hrtc) {
         // Exit Initialization mode
         hrtc->Instance->ISR &= (uint32_t)~RTC_ISR_INIT;
 
-        #if defined(MCU_SERIES_L4)
+        #if defined(MCU_SERIES_L4) || defined(STM32H7)
         hrtc->Instance->OR &= (uint32_t)~RTC_OR_ALARMOUTTYPE;
         hrtc->Instance->OR |= (uint32_t)(hrtc->Init.OutPutType);
         #elif defined(MCU_SERIES_F7)
@@ -634,6 +638,9 @@ mp_obj_t pyb_rtc_wakeup(size_t n_args, const mp_obj_t *args) {
         #if defined(MCU_SERIES_L4)
         EXTI->IMR1 |= 1 << 22;
         EXTI->RTSR1 |= 1 << 22;
+        #elif defined(STM32H7)
+        EXTI_D1->IMR1 |= 1 << 22;
+        EXTI->RTSR1   |= 1 << 22;
         #else
         EXTI->IMR |= 1 << 22;
         EXTI->RTSR |= 1 << 22;
@@ -643,6 +650,8 @@ mp_obj_t pyb_rtc_wakeup(size_t n_args, const mp_obj_t *args) {
         RTC->ISR &= ~(1 << 10);
         #if defined(MCU_SERIES_L4)
         EXTI->PR1 = 1 << 22;
+        #elif defined(STM32H7)
+        EXTI_D1->PR1 = 1 << 22;
         #else
         EXTI->PR = 1 << 22;
         #endif
@@ -661,6 +670,8 @@ mp_obj_t pyb_rtc_wakeup(size_t n_args, const mp_obj_t *args) {
         // disable external interrupts on line 22
         #if defined(MCU_SERIES_L4)
         EXTI->IMR1 &= ~(1 << 22);
+        #elif defined(STM32H7)
+        EXTI_D1->IMR1 |= 1 << 22;
         #else
         EXTI->IMR &= ~(1 << 22);
         #endif