From 9dfbb6cc169ab95f07876d97824fd2c3dae229a1 Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Tue, 31 Jul 2018 17:24:10 +1000
Subject: [PATCH] stm32/rtc: Get rtc.wakeup working on F0 MCUs.

The problem was that the EXTI line for the RTC wakeup event is line 20 on
the F0, so the interrupt was not firing.
---
 ports/stm32/extint.h   |  7 +++++++
 ports/stm32/rtc.c      | 39 ++++++++++++++++++++-------------------
 ports/stm32/stm32_it.c |  4 ++--
 3 files changed, 29 insertions(+), 21 deletions(-)

diff --git a/ports/stm32/extint.h b/ports/stm32/extint.h
index c4a4ae6bb9..2238ff4f85 100644
--- a/ports/stm32/extint.h
+++ b/ports/stm32/extint.h
@@ -26,6 +26,8 @@
 #ifndef MICROPY_INCLUDED_STM32_EXTINT_H
 #define MICROPY_INCLUDED_STM32_EXTINT_H
 
+#include "py/mphal.h"
+
 // Vectors 0-15 are for regular pins
 // Vectors 16-22 are for internal sources.
 //
@@ -36,8 +38,13 @@
 #define EXTI_USB_OTG_FS_WAKEUP  (18)
 #define EXTI_ETH_WAKEUP         (19)
 #define EXTI_USB_OTG_HS_WAKEUP  (20)
+#if defined(STM32F0)
+#define EXTI_RTC_TIMESTAMP      (19)
+#define EXTI_RTC_WAKEUP         (20)
+#else
 #define EXTI_RTC_TIMESTAMP      (21)
 #define EXTI_RTC_WAKEUP         (22)
+#endif
 #if defined(STM32F7)
 #define EXTI_LPTIM1_ASYNC_EVENT (23)
 #endif
diff --git a/ports/stm32/rtc.c b/ports/stm32/rtc.c
index dfc4591da9..1999dfb384 100644
--- a/ports/stm32/rtc.c
+++ b/ports/stm32/rtc.c
@@ -27,6 +27,7 @@
 #include <stdio.h>
 
 #include "py/runtime.h"
+#include "extint.h"
 #include "rtc.h"
 #include "irq.h"
 
@@ -612,17 +613,17 @@ mp_obj_t pyb_rtc_wakeup(size_t n_args, const mp_obj_t *args) {
     }
 
     // set the callback
-    MP_STATE_PORT(pyb_extint_callback)[22] = callback;
+    MP_STATE_PORT(pyb_extint_callback)[EXTI_RTC_WAKEUP] = callback;
 
     // disable register write protection
     RTC->WPR = 0xca;
     RTC->WPR = 0x53;
 
     // clear WUTE
-    RTC->CR &= ~(1 << 10);
+    RTC->CR &= ~RTC_CR_WUTE;
 
     // wait until WUTWF is set
-    while (!(RTC->ISR & (1 << 2))) {
+    while (!(RTC->ISR & RTC_ISR_WUTWF)) {
     }
 
     if (enable) {
@@ -637,26 +638,26 @@ mp_obj_t pyb_rtc_wakeup(size_t n_args, const mp_obj_t *args) {
         // enable register write protection
         RTC->WPR = 0xff;
 
-        // enable external interrupts on line 22
+        // enable external interrupts on line EXTI_RTC_WAKEUP
         #if defined(STM32L4)
-        EXTI->IMR1 |= 1 << 22;
-        EXTI->RTSR1 |= 1 << 22;
+        EXTI->IMR1 |= 1 << EXTI_RTC_WAKEUP;
+        EXTI->RTSR1 |= 1 << EXTI_RTC_WAKEUP;
         #elif defined(STM32H7)
-        EXTI_D1->IMR1 |= 1 << 22;
-        EXTI->RTSR1   |= 1 << 22;
+        EXTI_D1->IMR1 |= 1 << EXTI_RTC_WAKEUP;
+        EXTI->RTSR1 |= 1 << EXTI_RTC_WAKEUP;
         #else
-        EXTI->IMR |= 1 << 22;
-        EXTI->RTSR |= 1 << 22;
+        EXTI->IMR |= 1 << EXTI_RTC_WAKEUP;
+        EXTI->RTSR |= 1 << EXTI_RTC_WAKEUP;
         #endif
 
         // clear interrupt flags
-        RTC->ISR &= ~(1 << 10);
+        RTC->ISR &= ~RTC_ISR_WUTF;
         #if defined(STM32L4)
-        EXTI->PR1 = 1 << 22;
+        EXTI->PR1 = 1 << EXTI_RTC_WAKEUP;
         #elif defined(STM32H7)
-        EXTI_D1->PR1 = 1 << 22;
+        EXTI_D1->PR1 = 1 << EXTI_RTC_WAKEUP;
         #else
-        EXTI->PR = 1 << 22;
+        EXTI->PR = 1 << EXTI_RTC_WAKEUP;
         #endif
 
         NVIC_SetPriority(RTC_WKUP_IRQn, IRQ_PRI_RTC_WKUP);
@@ -665,18 +666,18 @@ mp_obj_t pyb_rtc_wakeup(size_t n_args, const mp_obj_t *args) {
         //printf("wut=%d wucksel=%d\n", wut, wucksel);
     } else {
         // clear WUTIE to disable interrupts
-        RTC->CR &= ~(1 << 14);
+        RTC->CR &= ~RTC_CR_WUTIE;
 
         // enable register write protection
         RTC->WPR = 0xff;
 
-        // disable external interrupts on line 22
+        // disable external interrupts on line EXTI_RTC_WAKEUP
         #if defined(STM32L4)
-        EXTI->IMR1 &= ~(1 << 22);
+        EXTI->IMR1 &= ~(1 << EXTI_RTC_WAKEUP);
         #elif defined(STM32H7)
-        EXTI_D1->IMR1 |= 1 << 22;
+        EXTI_D1->IMR1 |= 1 << EXTI_RTC_WAKEUP;
         #else
-        EXTI->IMR &= ~(1 << 22);
+        EXTI->IMR &= ~(1 << EXTI_RTC_WAKEUP);
         #endif
     }
 
diff --git a/ports/stm32/stm32_it.c b/ports/stm32/stm32_it.c
index a2a8d0f2e5..026082eb98 100644
--- a/ports/stm32/stm32_it.c
+++ b/ports/stm32/stm32_it.c
@@ -574,7 +574,7 @@ void TAMP_STAMP_IRQHandler(void) {
 
 void RTC_WKUP_IRQHandler(void) {
     IRQ_ENTER(RTC_WKUP_IRQn);
-    RTC->ISR &= ~(1 << 10); // clear wakeup interrupt flag
+    RTC->ISR &= ~RTC_ISR_WUTF; // clear wakeup interrupt flag
     Handle_EXTI_Irq(EXTI_RTC_WAKEUP); // clear EXTI flag and execute optional callback
     IRQ_EXIT(RTC_WKUP_IRQn);
 }
@@ -583,7 +583,7 @@ void RTC_WKUP_IRQHandler(void) {
 
 void RTC_IRQHandler(void) {
     IRQ_ENTER(RTC_IRQn);
-    RTC->ISR &= ~(1 << 10); // clear wakeup interrupt flag
+    RTC->ISR &= ~RTC_ISR_WUTF; // clear wakeup interrupt flag
     Handle_EXTI_Irq(EXTI_RTC_WAKEUP); // clear EXTI flag and execute optional callback
     IRQ_EXIT(RTC_IRQn);
 }