low_power: i2c wakeup

2 files changed, 11 insertions, 3 deletions

diff --git a/embassy-stm32/src/i2c/v2.rs b/embassy-stm32/src/i2c/v2.rs
index 01b6b8800..a2184630f 100644
--- a/embassy-stm32/src/i2c/v2.rs
+++ b/embassy-stm32/src/i2c/v2.rs
@@ -70,6 +70,11 @@ fn debug_print_interrupts(isr: stm32_metapac::i2c::regs::Isr) {
 }
 
 pub(crate) unsafe fn on_interrupt<T: Instance>() {
+    // restore the clocks to their last configured state as
+    // much is lost in STOP modes
+    #[cfg(all(feature = "low-power", stm32wlex))]
+    crate::low_power::on_wakeup_irq();
+
     let regs = T::info().regs;
     let isr = regs.isr().read();
 
diff --git a/embassy-stm32/src/low_power.rs b/embassy-stm32/src/low_power.rs
index 4ebded8a5..4cdaf6a00 100644
--- a/embassy-stm32/src/low_power.rs
+++ b/embassy-stm32/src/low_power.rs
@@ -180,16 +180,19 @@ impl Executor {
     }
 
     unsafe fn on_wakeup_irq(&mut self) {
+        // when we wake from STOP2, we need to re-initialize the rcc and the time driver
+        // to restore the clocks to their last configured state
+        #[cfg(stm32wlex)]
+        crate::rcc::apply_resume_config();
         #[cfg(stm32wlex)]
         if crate::pac::PWR.extscr().read().c1stop2f() {
-            // when we wake from STOP2, we need to re-initialize the rcc and the time driver
-            // to restore the clocks to their last configured state
-            crate::rcc::apply_resume_config();
             critical_section::with(|cs| crate::time_driver::init_timer(cs));
             // reset the refcounts for STOP2 and STOP1 (initializing the time driver will increment one of them for the timer)
+            // and given that we just woke from STOP2, we can reset them
             crate::rcc::REFCOUNT_STOP2 = 0;
             crate::rcc::REFCOUNT_STOP1 = 0;
         }
+
         self.time_driver.resume_time();
         trace!("low power: resume");
     }