5 files changed, 60 insertions, 80 deletions

diff --git a/embassy-stm32/src/exti.rs b/embassy-stm32/src/exti.rs
index 925cf39be..bd4bab1f8 100644
--- a/embassy-stm32/src/exti.rs
+++ b/embassy-stm32/src/exti.rs
@@ -39,6 +39,9 @@ fn exticr_regs() -> pac::afio::Afio {
 }
 
 pub unsafe fn on_irq() {
+    #[cfg(feature = "low-power")]
+    crate::low_power::on_wakeup_irq();
+
     #[cfg(not(any(exti_c0, exti_g0, exti_l5, exti_u5, exti_h5, exti_h50)))]
     let bits = EXTI.pr(0).read().0;
     #[cfg(any(exti_c0, exti_g0, exti_l5, exti_u5, exti_h5, exti_h50))]
diff --git a/embassy-stm32/src/low_power.rs b/embassy-stm32/src/low_power.rs
index b42b674e1..ce8afb578 100644
--- a/embassy-stm32/src/low_power.rs
+++ b/embassy-stm32/src/low_power.rs
@@ -5,7 +5,6 @@ use cortex_m::peripheral::SCB;
 use embassy_executor::*;
 
 use crate::interrupt;
-use crate::interrupt::typelevel::Interrupt;
 use crate::rcc::low_power_ready;
 use crate::time_driver::{get_driver, RtcDriver};
 
@@ -19,36 +18,20 @@ foreach_interrupt! {
     (RTC, rtc, $block:ident, WKUP, $irq:ident) => {
         #[interrupt]
         unsafe fn $irq() {
-            unsafe { EXECUTOR.as_mut().unwrap() }.on_wakeup_irq();
+            EXECUTOR.as_mut().unwrap().on_wakeup_irq();
         }
     };
 }
 
-// pub fn timer_driver_pause_time() {
-//     pause_time();
-// }
+#[allow(dead_code)]
+pub(crate) unsafe fn on_wakeup_irq() {
+    EXECUTOR.as_mut().unwrap().on_wakeup_irq();
+}
 
 pub fn stop_with_rtc(rtc: &'static Rtc) {
     unsafe { EXECUTOR.as_mut().unwrap() }.stop_with_rtc(rtc)
 }
 
-// pub fn start_wakeup_alarm(requested_duration: embassy_time::Duration) {
-//     let rtc_instant = unsafe { EXECUTOR.as_mut().unwrap() }
-//         .rtc
-//         .unwrap()
-//         .start_wakeup_alarm(requested_duration);
-//
-//     unsafe { EXECUTOR.as_mut().unwrap() }.last_stop = Some(rtc_instant);
-// }
-//
-// pub fn set_sleepdeep() {
-//     unsafe { EXECUTOR.as_mut().unwrap() }.scb.set_sleepdeep();
-// }
-//
-// pub fn stop_wakeup_alarm() -> RtcInstant {
-//     unsafe { EXECUTOR.as_mut().unwrap() }.rtc.unwrap().stop_wakeup_alarm()
-// }
-
 /// Thread mode executor, using WFE/SEV.
 ///
 /// This is the simplest and most common kind of executor. It runs on
@@ -91,27 +74,11 @@ impl Executor {
     }
 
     pub(self) fn stop_with_rtc(&mut self, rtc: &'static Rtc) {
-        trace!("low power: stop with rtc configured");
-
         self.time_driver.set_rtc(rtc);
 
-        #[cfg(not(stm32l0))]
-        crate::interrupt::typelevel::RTC_WKUP::unpend();
-
-        #[cfg(not(stm32l0))]
-        unsafe {
-            crate::interrupt::typelevel::RTC_WKUP::enable()
-        };
-
-        #[cfg(stm32l0)]
-        crate::interrupt::typelevel::RTC::unpend();
-
-        #[cfg(stm32l0)]
-        unsafe {
-            crate::interrupt::typelevel::RTC::enable()
-        };
-
         rtc.enable_wakeup_line();
+
+        trace!("low power: stop with rtc configured");
     }
 
     fn configure_pwr(&mut self) {
diff --git a/embassy-stm32/src/rtc/mod.rs b/embassy-stm32/src/rtc/mod.rs
index a1133a80b..32a5cc123 100644
--- a/embassy-stm32/src/rtc/mod.rs
+++ b/embassy-stm32/src/rtc/mod.rs
@@ -124,9 +124,6 @@ impl Default for RtcCalibrationCyclePeriod {
 
 impl Rtc {
     pub fn new(_rtc: impl Peripheral<P = RTC>, rtc_config: RtcConfig) -> Self {
-        #[cfg(any(rcc_wb, rcc_f4, rcc_f410))]
-        use crate::rcc::get_freqs;
-
         RTC::enable_peripheral_clk();
         BackupDomain::enable_rtc();
 
@@ -135,26 +132,29 @@ impl Rtc {
             stop_time: Mutex::const_new(CriticalSectionRawMutex::new(), Cell::new(None)),
         };
 
+        let frequency = Self::frequency();
+        let async_psc = ((frequency.0 / rtc_config.frequency.0) - 1) as u8;
+        let sync_psc = (rtc_config.frequency.0 - 1) as u16;
+
+        this.configure(async_psc, sync_psc);
+
+        this
+    }
+
+    fn frequency() -> Hertz {
         #[cfg(any(rcc_wb, rcc_f4, rcc_f410))]
-        let freqs = unsafe { get_freqs() };
+        let freqs = unsafe { crate::rcc::get_freqs() };
 
         // Load the clock frequency from the rcc mod, if supported
         #[cfg(any(rcc_wb, rcc_f4, rcc_f410))]
-        let frequency = match freqs.rtc {
+        match freqs.rtc {
             Some(hertz) => hertz,
             None => freqs.rtc_hse.unwrap(),
-        };
+        }
 
         // Assume the  default value, if not supported
         #[cfg(not(any(rcc_wb, rcc_f4, rcc_f410)))]
-        let frequency = Hertz(32_768);
-
-        let async_psc = ((frequency.0 / rtc_config.frequency.0) - 1) as u8;
-        let sync_psc = (rtc_config.frequency.0 - 1) as u16;
-
-        this.configure(async_psc, sync_psc);
-
-        this
+        Hertz(32_768)
     }
 
     /// Set the datetime to a new value.
@@ -264,6 +264,12 @@ pub(crate) mod sealed {
     pub trait Instance {
         const BACKUP_REGISTER_COUNT: usize;
 
+        #[cfg(feature = "low-power")]
+        const EXTI_WAKEUP_LINE: usize;
+
+        #[cfg(feature = "low-power")]
+        type WakeupInterrupt: crate::interrupt::typelevel::Interrupt;
+
         fn regs() -> Rtc {
             crate::pac::RTC
         }
diff --git a/embassy-stm32/src/rtc/v2.rs b/embassy-stm32/src/rtc/v2.rs
index 726886f10..aa3c31ee1 100644
--- a/embassy-stm32/src/rtc/v2.rs
+++ b/embassy-stm32/src/rtc/v2.rs
@@ -67,15 +67,10 @@ impl super::Rtc {
     pub(crate) fn start_wakeup_alarm(&self, requested_duration: embassy_time::Duration) {
         use embassy_time::{Duration, TICK_HZ};
 
-        #[cfg(not(stm32l0))]
-        use crate::rcc::get_freqs;
-
-        #[cfg(not(stm32l0))]
-        let rtc_hz = unsafe { get_freqs() }.rtc.unwrap().0 as u64;
-
-        #[cfg(stm32l0)]
-        let rtc_hz = 32_768u64;
+        #[cfg(any(rcc_wb, rcc_f4, rcc_f410))]
+        unsafe { crate::rcc::get_freqs() }.rtc.unwrap();
 
+        let rtc_hz = Self::frequency().0 as u64;
         let rtc_ticks = requested_duration.as_ticks() * rtc_hz / TICK_HZ;
         let prescaler = WakeupPrescaler::compute_min((rtc_ticks / u16::MAX as u64) as u32);
 
@@ -112,17 +107,14 @@ impl super::Rtc {
 
     #[cfg(feature = "low-power")]
     pub(crate) fn enable_wakeup_line(&self) {
+        use crate::interrupt::typelevel::Interrupt;
         use crate::pac::EXTI;
 
-        #[cfg(stm32l0)]
-        EXTI.rtsr(0).modify(|w| w.set_line(20, true));
-        #[cfg(stm32l0)]
-        EXTI.imr(0).modify(|w| w.set_line(20, true));
+        <RTC as crate::rtc::sealed::Instance>::WakeupInterrupt::unpend();
+        unsafe { <RTC as crate::rtc::sealed::Instance>::WakeupInterrupt::enable() };
 
-        #[cfg(not(stm32l0))]
-        EXTI.rtsr(0).modify(|w| w.set_line(22, true));
-        #[cfg(not(stm32l0))]
-        EXTI.imr(0).modify(|w| w.set_line(22, true));
+        EXTI.rtsr(0).modify(|w| w.set_line(RTC::EXTI_WAKEUP_LINE, true));
+        EXTI.imr(0).modify(|w| w.set_line(RTC::EXTI_WAKEUP_LINE, true));
     }
 
     #[cfg(feature = "low-power")]
@@ -138,17 +130,11 @@ impl super::Rtc {
             regs.cr().modify(|w| w.set_wute(false));
             regs.isr().modify(|w| w.set_wutf(false));
 
-            #[cfg(not(stm32l0))]
-            crate::pac::EXTI.pr(0).modify(|w| w.set_line(22, true));
-
-            #[cfg(stm32l0)]
-            crate::pac::EXTI.pr(0).modify(|w| w.set_line(20, true));
-
-            #[cfg(not(stm32l0))]
-            crate::interrupt::typelevel::RTC_WKUP::unpend();
+            crate::pac::EXTI
+                .pr(0)
+                .modify(|w| w.set_line(RTC::EXTI_WAKEUP_LINE, true));
 
-            #[cfg(stm32l0)]
-            crate::interrupt::typelevel::RTC::unpend();
+            <RTC as crate::rtc::sealed::Instance>::WakeupInterrupt::unpend();
         });
 
         critical_section::with(|cs| {
@@ -280,6 +266,18 @@ impl super::Rtc {
 impl sealed::Instance for crate::peripherals::RTC {
     const BACKUP_REGISTER_COUNT: usize = 20;
 
+    #[cfg(all(feature = "low-power", stm32f4))]
+    const EXTI_WAKEUP_LINE: usize = 22;
+
+    #[cfg(all(feature = "low-power", stm32l0))]
+    const EXTI_WAKEUP_LINE: usize = 20;
+
+    #[cfg(all(feature = "low-power", stm32f4))]
+    type WakeupInterrupt = crate::interrupt::typelevel::RTC_WKUP;
+
+    #[cfg(all(feature = "low-power", stm32l0))]
+    type WakeupInterrupt = crate::interrupt::typelevel::RTC;
+
     fn enable_peripheral_clk() {
         #[cfg(any(rtc_v2l4, rtc_v2wb))]
         {
diff --git a/embassy-stm32/src/time_driver.rs b/embassy-stm32/src/time_driver.rs
index 99d423d08..887e54f65 100644
--- a/embassy-stm32/src/time_driver.rs
+++ b/embassy-stm32/src/time_driver.rs
@@ -372,6 +372,12 @@ impl RtcDriver {
     #[cfg(feature = "low-power")]
     /// Resume the timer with the given offset
     pub(crate) fn resume_time(&self) {
+        if T::regs_gp16().cr1().read().cen() {
+            // Time isn't currently stopped
+
+            return;
+        }
+
         self.stop_wakeup_alarm();
 
         T::regs_gp16().cr1().modify(|w| w.set_cen(true));