Merge remote-tracking branch 'origin/main' into feature/spi-bidi

11 files changed, 218 insertions, 216 deletions

diff --git a/embassy-stm32/src/can/enums.rs b/embassy-stm32/src/can/enums.rs
index 6d91020fc..c5900cadc 100644
--- a/embassy-stm32/src/can/enums.rs
+++ b/embassy-stm32/src/can/enums.rs
@@ -82,3 +82,40 @@ pub enum RefCountOp {
     /// Notify sender destroyed
     NotifySenderDestroyed,
 }
+
+/// Error returned when calculating the can timing fails
+#[derive(Debug)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum TimingCalcError {
+    /// Bitrate is lower than 1000
+    BitrateTooLow {
+        /// The set bitrate
+        bitrate: u32,
+    },
+    /// No solution possible
+    NoSolution {
+        /// The sum of BS1 and BS2
+        bs1_bs2_sum: u8,
+    },
+    /// Prescaler is not 1 < prescaler < 1024
+    InvalidPrescaler {
+        /// The calculated prescaler value
+        prescaler: u32,
+    },
+    /// BS1 or BS2 are not in the range 0 < BSx < BSx_MAX
+    BSNotInRange {
+        /// The value of BS1
+        bs1: u8,
+        /// The value of BS2
+        bs2: u8,
+    },
+    /// Final bitrate doesn't match the requested bitrate
+    NoMatch {
+        /// The requested bitrate
+        requested: u32,
+        /// The calculated bitrate
+        final_calculated: u32,
+    },
+    /// core::num::NonZeroUxx::new error
+    CoreNumNew,
+}
diff --git a/embassy-stm32/src/can/util.rs b/embassy-stm32/src/can/util.rs
index 6d7f0c16a..beca4c34e 100644
--- a/embassy-stm32/src/can/util.rs
+++ b/embassy-stm32/src/can/util.rs
@@ -2,6 +2,8 @@
 
 use core::num::{NonZeroU8, NonZeroU16};
 
+use crate::can::enums::TimingCalcError;
+
 /// Shared struct to represent bit timings used by calc_can_timings.
 #[derive(Clone, Copy, Debug)]
 pub struct NominalBitTiming {
@@ -17,7 +19,10 @@ pub struct NominalBitTiming {
 }
 
 /// Calculate nominal CAN bit timing based on CAN bitrate and periphial clock frequency
-pub fn calc_can_timings(periph_clock: crate::time::Hertz, can_bitrate: u32) -> Option<NominalBitTiming> {
+pub fn calc_can_timings(
+    periph_clock: crate::time::Hertz,
+    can_bitrate: u32,
+) -> Result<NominalBitTiming, TimingCalcError> {
     const BS1_MAX: u8 = 16;
     const BS2_MAX: u8 = 8;
     const MAX_SAMPLE_POINT_PERMILL: u16 = 900;
@@ -25,7 +30,7 @@ pub fn calc_can_timings(periph_clock: crate::time::Hertz, can_bitrate: u32) -> O
     let periph_clock = periph_clock.0;
 
     if can_bitrate < 1000 {
-        return None;
+        return Err(TimingCalcError::BitrateTooLow { bitrate: can_bitrate });
     }
 
     // Ref. "Automatic Baudrate Detection in CANopen Networks", U. Koppe, MicroControl GmbH & Co. KG
@@ -53,14 +58,14 @@ pub fn calc_can_timings(periph_clock: crate::time::Hertz, can_bitrate: u32) -> O
     let mut bs1_bs2_sum = max_quanta_per_bit - 1;
     while (prescaler_bs % (1 + bs1_bs2_sum) as u32) != 0 {
         if bs1_bs2_sum <= 2 {
-            return None; // No solution
+            return Err(TimingCalcError::NoSolution { bs1_bs2_sum }); // No solution
         }
         bs1_bs2_sum -= 1;
     }
 
     let prescaler = prescaler_bs / (1 + bs1_bs2_sum) as u32;
     if (prescaler < 1) || (prescaler > 1024) {
-        return None; // No solution
+        return Err(TimingCalcError::InvalidPrescaler { prescaler }); // No solution
     }
 
     // Now we have a constraint: (BS1 + BS2) == bs1_bs2_sum.
@@ -93,22 +98,26 @@ pub fn calc_can_timings(periph_clock: crate::time::Hertz, can_bitrate: u32) -> O
 
     // Check is BS1 and BS2 are in range
     if (bs1 < 1) || (bs1 > BS1_MAX) || (bs2 < 1) || (bs2 > BS2_MAX) {
-        return None;
+        return Err(TimingCalcError::BSNotInRange { bs1, bs2 });
     }
 
+    let calculated = periph_clock / (prescaler * (1 + bs1 + bs2) as u32);
     // Check if final bitrate matches the requested
-    if can_bitrate != (periph_clock / (prescaler * (1 + bs1 + bs2) as u32)) {
-        return None;
+    if can_bitrate != calculated {
+        return Err(TimingCalcError::NoMatch {
+            requested: can_bitrate,
+            final_calculated: calculated,
+        });
     }
 
     // One is recommended by DS-015, CANOpen, and DeviceNet
-    let sync_jump_width = core::num::NonZeroU8::new(1)?;
+    let sync_jump_width = core::num::NonZeroU8::new(1).ok_or(TimingCalcError::CoreNumNew)?;
 
-    let seg1 = core::num::NonZeroU8::new(bs1)?;
-    let seg2 = core::num::NonZeroU8::new(bs2)?;
-    let nz_prescaler = core::num::NonZeroU16::new(prescaler as u16)?;
+    let seg1 = core::num::NonZeroU8::new(bs1).ok_or(TimingCalcError::CoreNumNew)?;
+    let seg2 = core::num::NonZeroU8::new(bs2).ok_or(TimingCalcError::CoreNumNew)?;
+    let nz_prescaler = core::num::NonZeroU16::new(prescaler as u16).ok_or(TimingCalcError::CoreNumNew)?;
 
-    Some(NominalBitTiming {
+    Ok(NominalBitTiming {
         sync_jump_width,
         prescaler: nz_prescaler,
         seg1,
diff --git a/embassy-stm32/src/dma/dma_bdma.rs b/embassy-stm32/src/dma/dma_bdma.rs
index b46ae2813..adc084474 100644
--- a/embassy-stm32/src/dma/dma_bdma.rs
+++ b/embassy-stm32/src/dma/dma_bdma.rs
@@ -8,8 +8,9 @@ use embassy_sync::waitqueue::AtomicWaker;
 
 use super::ringbuffer::{DmaCtrl, Error, ReadableDmaRingBuffer, WritableDmaRingBuffer};
 use super::word::{Word, WordSize};
-use super::{AnyChannel, BusyChannel, Channel, Dir, Request, STATE};
+use super::{AnyChannel, Channel, Dir, Request, STATE};
 use crate::interrupt::typelevel::Interrupt;
+use crate::rcc::BusyPeripheral;
 use crate::{interrupt, pac};
 
 pub(crate) struct ChannelInfo {
@@ -602,7 +603,7 @@ impl AnyChannel {
 /// DMA transfer.
 #[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct Transfer<'a> {
-    channel: BusyChannel<'a>,
+    channel: BusyPeripheral<Peri<'a, AnyChannel>>,
 }
 
 impl<'a> Transfer<'a> {
@@ -714,7 +715,7 @@ impl<'a> Transfer<'a> {
         );
         channel.start();
         Self {
-            channel: BusyChannel::new(channel),
+            channel: BusyPeripheral::new(channel),
         }
     }
 
@@ -818,7 +819,7 @@ impl<'a> DmaCtrl for DmaCtrlImpl<'a> {
 
 /// Ringbuffer for receiving data using DMA circular mode.
 pub struct ReadableRingBuffer<'a, W: Word> {
-    channel: BusyChannel<'a>,
+    channel: BusyPeripheral<Peri<'a, AnyChannel>>,
     ringbuf: ReadableDmaRingBuffer<'a, W>,
 }
 
@@ -855,7 +856,7 @@ impl<'a, W: Word> ReadableRingBuffer<'a, W> {
         );
 
         Self {
-            channel: BusyChannel::new(channel),
+            channel: BusyPeripheral::new(channel),
             ringbuf: ReadableDmaRingBuffer::new(buffer),
         }
     }
@@ -974,7 +975,7 @@ impl<'a, W: Word> Drop for ReadableRingBuffer<'a, W> {
 
 /// Ringbuffer for writing data using DMA circular mode.
 pub struct WritableRingBuffer<'a, W: Word> {
-    channel: BusyChannel<'a>,
+    channel: BusyPeripheral<Peri<'a, AnyChannel>>,
     ringbuf: WritableDmaRingBuffer<'a, W>,
 }
 
@@ -1011,7 +1012,7 @@ impl<'a, W: Word> WritableRingBuffer<'a, W> {
         );
 
         Self {
-            channel: BusyChannel::new(channel),
+            channel: BusyPeripheral::new(channel),
             ringbuf: WritableDmaRingBuffer::new(buffer),
         }
     }
diff --git a/embassy-stm32/src/dma/gpdma/mod.rs b/embassy-stm32/src/dma/gpdma/mod.rs
index 383c74a78..bfd0570f8 100644
--- a/embassy-stm32/src/dma/gpdma/mod.rs
+++ b/embassy-stm32/src/dma/gpdma/mod.rs
@@ -11,10 +11,10 @@ use linked_list::Table;
 
 use super::word::{Word, WordSize};
 use super::{AnyChannel, Channel, Dir, Request, STATE};
-use crate::dma::BusyChannel;
 use crate::interrupt::typelevel::Interrupt;
 use crate::pac;
 use crate::pac::gpdma::vals;
+use crate::rcc::BusyPeripheral;
 
 pub mod linked_list;
 pub mod ringbuffered;
@@ -409,7 +409,7 @@ impl AnyChannel {
 /// Linked-list DMA transfer.
 #[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct LinkedListTransfer<'a, const ITEM_COUNT: usize> {
-    channel: BusyChannel<'a>,
+    channel: BusyPeripheral<Peri<'a, AnyChannel>>,
 }
 
 impl<'a, const ITEM_COUNT: usize> LinkedListTransfer<'a, ITEM_COUNT> {
@@ -431,7 +431,7 @@ impl<'a, const ITEM_COUNT: usize> LinkedListTransfer<'a, ITEM_COUNT> {
         channel.start();
 
         Self {
-            channel: BusyChannel::new(channel),
+            channel: BusyPeripheral::new(channel),
         }
     }
 
@@ -508,7 +508,7 @@ impl<'a, const ITEM_COUNT: usize> Future for LinkedListTransfer<'a, ITEM_COUNT>
 /// DMA transfer.
 #[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct Transfer<'a> {
-    channel: BusyChannel<'a>,
+    channel: BusyPeripheral<Peri<'a, AnyChannel>>,
 }
 
 impl<'a> Transfer<'a> {
@@ -629,7 +629,7 @@ impl<'a> Transfer<'a> {
         channel.start();
 
         Self {
-            channel: BusyChannel::new(channel),
+            channel: BusyPeripheral::new(channel),
         }
     }
 
diff --git a/embassy-stm32/src/dma/gpdma/ringbuffered.rs b/embassy-stm32/src/dma/gpdma/ringbuffered.rs
index 54e4d5f71..c150d0b95 100644
--- a/embassy-stm32/src/dma/gpdma/ringbuffered.rs
+++ b/embassy-stm32/src/dma/gpdma/ringbuffered.rs
@@ -12,7 +12,8 @@ use super::{AnyChannel, STATE, TransferOptions};
 use crate::dma::gpdma::linked_list::{RunMode, Table};
 use crate::dma::ringbuffer::{DmaCtrl, Error, ReadableDmaRingBuffer, WritableDmaRingBuffer};
 use crate::dma::word::Word;
-use crate::dma::{BusyChannel, Channel, Dir, Request};
+use crate::dma::{Channel, Dir, Request};
+use crate::rcc::BusyPeripheral;
 
 struct DmaCtrlImpl<'a>(Peri<'a, AnyChannel>);
 
@@ -49,7 +50,7 @@ impl<'a> DmaCtrl for DmaCtrlImpl<'a> {
 
 /// Ringbuffer for receiving data using GPDMA linked-list mode.
 pub struct ReadableRingBuffer<'a, W: Word> {
-    channel: BusyChannel<'a>,
+    channel: BusyPeripheral<Peri<'a, AnyChannel>>,
     ringbuf: ReadableDmaRingBuffer<'a, W>,
     table: Table<2>,
     options: TransferOptions,
@@ -70,7 +71,7 @@ impl<'a, W: Word> ReadableRingBuffer<'a, W> {
         let table = Table::<2>::new_ping_pong::<W>(request, peri_addr, buffer, Dir::PeripheralToMemory);
 
         Self {
-            channel: BusyChannel::new(channel),
+            channel: BusyPeripheral::new(channel),
             ringbuf: ReadableDmaRingBuffer::new(buffer),
             table,
             options,
@@ -189,7 +190,7 @@ impl<'a, W: Word> Drop for ReadableRingBuffer<'a, W> {
 
 /// Ringbuffer for writing data using GPDMA linked-list mode.
 pub struct WritableRingBuffer<'a, W: Word> {
-    channel: BusyChannel<'a>,
+    channel: BusyPeripheral<Peri<'a, AnyChannel>>,
     ringbuf: WritableDmaRingBuffer<'a, W>,
     table: Table<2>,
     options: TransferOptions,
@@ -210,7 +211,7 @@ impl<'a, W: Word> WritableRingBuffer<'a, W> {
         let table = Table::<2>::new_ping_pong::<W>(request, peri_addr, buffer, Dir::MemoryToPeripheral);
 
         Self {
-            channel: BusyChannel::new(channel),
+            channel: BusyPeripheral::new(channel),
             ringbuf: WritableDmaRingBuffer::new(buffer),
             table,
             options,
diff --git a/embassy-stm32/src/dma/mod.rs b/embassy-stm32/src/dma/mod.rs
index 4becc2d87..efb324fa6 100644
--- a/embassy-stm32/src/dma/mod.rs
+++ b/embassy-stm32/src/dma/mod.rs
@@ -3,14 +3,12 @@
 
 #[cfg(any(bdma, dma))]
 mod dma_bdma;
-use core::ops;
 
 #[cfg(any(bdma, dma))]
 pub use dma_bdma::*;
 
 #[cfg(gpdma)]
 pub(crate) mod gpdma;
-use embassy_hal_internal::Peri;
 #[cfg(gpdma)]
 pub use gpdma::ringbuffered::*;
 #[cfg(gpdma)]
@@ -27,9 +25,10 @@ pub(crate) use util::*;
 pub(crate) mod ringbuffer;
 pub mod word;
 
-use embassy_hal_internal::{PeripheralType, impl_peripheral};
+use embassy_hal_internal::{Peri, PeripheralType, impl_peripheral};
 
 use crate::interrupt;
+use crate::rcc::StoppablePeripheral;
 
 /// The direction of a DMA transfer.
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
@@ -48,6 +47,13 @@ pub type Request = u8;
 #[cfg(not(any(dma_v2, bdma_v2, gpdma, dmamux)))]
 pub type Request = ();
 
+impl<'a> StoppablePeripheral for Peri<'a, AnyChannel> {
+    #[cfg(feature = "low-power")]
+    fn stop_mode(&self) -> crate::rcc::StopMode {
+        self.stop_mode
+    }
+}
+
 pub(crate) trait SealedChannel {
     #[cfg(not(stm32n6))]
     fn id(&self) -> u8;
@@ -103,44 +109,6 @@ macro_rules! dma_channel_impl {
     };
 }
 
-pub(crate) struct BusyChannel<'a> {
-    channel: Peri<'a, AnyChannel>,
-}
-
-impl<'a> BusyChannel<'a> {
-    pub fn new(channel: Peri<'a, AnyChannel>) -> Self {
-        #[cfg(feature = "low-power")]
-        critical_section::with(|cs| {
-            crate::rcc::increment_stop_refcount(cs, channel.stop_mode);
-        });
-
-        Self { channel }
-    }
-}
-
-impl<'a> Drop for BusyChannel<'a> {
-    fn drop(&mut self) {
-        #[cfg(feature = "low-power")]
-        critical_section::with(|cs| {
-            crate::rcc::decrement_stop_refcount(cs, self.stop_mode);
-        });
-    }
-}
-
-impl<'a> ops::Deref for BusyChannel<'a> {
-    type Target = Peri<'a, AnyChannel>;
-
-    fn deref(&self) -> &Self::Target {
-        &self.channel
-    }
-}
-
-impl<'a> ops::DerefMut for BusyChannel<'a> {
-    fn deref_mut(&mut self) -> &mut Self::Target {
-        &mut self.channel
-    }
-}
-
 /// Type-erased DMA channel.
 pub struct AnyChannel {
     pub(crate) id: u8,
diff --git a/embassy-stm32/src/low_power.rs b/embassy-stm32/src/low_power.rs
index bd8290da0..cdf3323fb 100644
--- a/embassy-stm32/src/low_power.rs
+++ b/embassy-stm32/src/low_power.rs
@@ -51,7 +51,7 @@ use embassy_executor::*;
 
 use crate::interrupt;
 pub use crate::rcc::StopMode;
-use crate::rcc::{RCC_CONFIG, REFCOUNT_STOP1, REFCOUNT_STOP2, decrement_stop_refcount, increment_stop_refcount};
+use crate::rcc::{BusyPeripheral, RCC_CONFIG, REFCOUNT_STOP1, REFCOUNT_STOP2};
 use crate::time_driver::get_driver;
 
 const THREAD_PENDER: usize = usize::MAX;
@@ -59,7 +59,9 @@ const THREAD_PENDER: usize = usize::MAX;
 static mut EXECUTOR_TAKEN: bool = false;
 
 /// Prevent the device from going into the stop mode if held
-pub struct DeviceBusy(StopMode);
+pub struct DeviceBusy {
+    _stop_mode: BusyPeripheral<StopMode>,
+}
 
 impl DeviceBusy {
     /// Create a new DeviceBusy with stop1.
@@ -74,19 +76,9 @@ impl DeviceBusy {
 
     /// Create a new DeviceBusy.
     pub fn new(stop_mode: StopMode) -> Self {
-        critical_section::with(|cs| {
-            increment_stop_refcount(cs, stop_mode);
-        });
-
-        Self(stop_mode)
-    }
-}
-
-impl Drop for DeviceBusy {
-    fn drop(&mut self) {
-        critical_section::with(|cs| {
-            decrement_stop_refcount(cs, self.0);
-        });
+        Self {
+            _stop_mode: BusyPeripheral::new(stop_mode),
+        }
     }
 }
 
diff --git a/embassy-stm32/src/rcc/mod.rs b/embassy-stm32/src/rcc/mod.rs
index 85434fa83..1dd634cfe 100644
--- a/embassy-stm32/src/rcc/mod.rs
+++ b/embassy-stm32/src/rcc/mod.rs
@@ -4,6 +4,7 @@
 #![allow(missing_docs)] // TODO
 
 use core::mem::MaybeUninit;
+use core::ops;
 
 mod bd;
 pub use bd::*;
@@ -112,7 +113,7 @@ pub fn clocks<'a>(_rcc: &'a crate::Peri<'a, crate::peripherals::RCC>) -> &'a Clo
 }
 
 #[cfg(feature = "low-power")]
-pub(crate) fn increment_stop_refcount(_cs: CriticalSection, stop_mode: StopMode) {
+fn increment_stop_refcount(_cs: CriticalSection, stop_mode: StopMode) {
     match stop_mode {
         StopMode::Standby => {}
         StopMode::Stop2 => unsafe {
@@ -125,7 +126,7 @@ pub(crate) fn increment_stop_refcount(_cs: CriticalSection, stop_mode: StopMode)
 }
 
 #[cfg(feature = "low-power")]
-pub(crate) fn decrement_stop_refcount(_cs: CriticalSection, stop_mode: StopMode) {
+fn decrement_stop_refcount(_cs: CriticalSection, stop_mode: StopMode) {
     match stop_mode {
         StopMode::Standby => {}
         StopMode::Stop2 => unsafe {
@@ -182,6 +183,12 @@ pub enum StopMode {
     Standby,
 }
 
+#[cfg(feature = "low-power")]
+type BusyRccPeripheral = BusyPeripheral<StopMode>;
+
+#[cfg(not(feature = "low-power"))]
+type BusyRccPeripheral = ();
+
 impl RccInfo {
     /// Safety:
     /// - `reset_offset_and_bit`, if set, must correspond to valid xxxRST bit
@@ -234,9 +241,6 @@ impl RccInfo {
             }
         }
 
-        #[cfg(feature = "low-power")]
-        increment_stop_refcount(_cs, self.stop_mode);
-
         // set the xxxRST bit
         let reset_ptr = self.reset_ptr();
         if let Some(reset_ptr) = reset_ptr {
@@ -292,9 +296,6 @@ impl RccInfo {
             }
         }
 
-        #[cfg(feature = "low-power")]
-        decrement_stop_refcount(_cs, self.stop_mode);
-
         // clear the xxxEN bit
         let enable_ptr = self.enable_ptr();
         unsafe {
@@ -303,16 +304,63 @@ impl RccInfo {
         }
     }
 
+    #[allow(dead_code)]
+    pub(crate) fn increment_stop_refcount_with_cs(&self, _cs: CriticalSection) {
+        #[cfg(feature = "low-power")]
+        increment_stop_refcount(_cs, self.stop_mode);
+    }
+
+    #[allow(dead_code)]
+    pub(crate) fn increment_stop_refcount(&self) {
+        #[cfg(feature = "low-power")]
+        critical_section::with(|cs| self.increment_stop_refcount_with_cs(cs))
+    }
+
+    #[allow(dead_code)]
+    pub(crate) fn decrement_stop_refcount_with_cs(&self, _cs: CriticalSection) {
+        #[cfg(feature = "low-power")]
+        decrement_stop_refcount(_cs, self.stop_mode);
+    }
+
+    #[allow(dead_code)]
+    pub(crate) fn decrement_stop_refcount(&self) {
+        #[cfg(feature = "low-power")]
+        critical_section::with(|cs| self.decrement_stop_refcount_with_cs(cs))
+    }
+
     // TODO: should this be `unsafe`?
     pub(crate) fn enable_and_reset(&self) {
+        critical_section::with(|cs| {
+            self.enable_and_reset_with_cs(cs);
+            self.increment_stop_refcount_with_cs(cs);
+        })
+    }
+
+    #[allow(dead_code)]
+    pub(crate) fn enable_and_reset_without_stop(&self) {
         critical_section::with(|cs| self.enable_and_reset_with_cs(cs))
     }
 
     // TODO: should this be `unsafe`?
     pub(crate) fn disable(&self) {
+        critical_section::with(|cs| {
+            self.disable_with_cs(cs);
+            self.decrement_stop_refcount_with_cs(cs);
+        })
+    }
+
+    // TODO: should this be `unsafe`?
+    #[allow(dead_code)]
+    pub(crate) fn disable_without_stop(&self) {
         critical_section::with(|cs| self.disable_with_cs(cs))
     }
 
+    #[allow(dead_code)]
+    pub(crate) fn block_stop(&self) -> BusyRccPeripheral {
+        #[cfg(feature = "low-power")]
+        BusyPeripheral::new(self.stop_mode)
+    }
+
     fn reset_ptr(&self) -> Option<*mut u32> {
         if self.reset_offset_or_0xff != 0xff {
             Some(unsafe { (RCC.as_ptr() as *mut u32).add(self.reset_offset_or_0xff as _) })
@@ -326,6 +374,53 @@ impl RccInfo {
     }
 }
 
+pub(crate) trait StoppablePeripheral {
+    #[cfg(feature = "low-power")]
+    #[allow(dead_code)]
+    fn stop_mode(&self) -> StopMode;
+}
+
+#[cfg(feature = "low-power")]
+impl<'a> StoppablePeripheral for StopMode {
+    fn stop_mode(&self) -> StopMode {
+        *self
+    }
+}
+
+pub(crate) struct BusyPeripheral<T: StoppablePeripheral> {
+    peripheral: T,
+}
+
+impl<T: StoppablePeripheral> BusyPeripheral<T> {
+    pub fn new(peripheral: T) -> Self {
+        #[cfg(feature = "low-power")]
+        critical_section::with(|cs| increment_stop_refcount(cs, peripheral.stop_mode()));
+
+        Self { peripheral }
+    }
+}
+
+impl<T: StoppablePeripheral> Drop for BusyPeripheral<T> {
+    fn drop(&mut self) {
+        #[cfg(feature = "low-power")]
+        critical_section::with(|cs| decrement_stop_refcount(cs, self.peripheral.stop_mode()));
+    }
+}
+
+impl<T: StoppablePeripheral> ops::Deref for BusyPeripheral<T> {
+    type Target = T;
+
+    fn deref(&self) -> &Self::Target {
+        &self.peripheral
+    }
+}
+
+impl<T: StoppablePeripheral> ops::DerefMut for BusyPeripheral<T> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.peripheral
+    }
+}
+
 #[allow(unused)]
 mod util {
     use crate::time::Hertz;
diff --git a/embassy-stm32/src/time_driver.rs b/embassy-stm32/src/time_driver.rs
index 0b75aef92..cfcf5f3fd 100644
--- a/embassy-stm32/src/time_driver.rs
+++ b/embassy-stm32/src/time_driver.rs
@@ -14,11 +14,11 @@ use stm32_metapac::timer::{TimGp16, regs};
 
 use crate::interrupt::typelevel::Interrupt;
 use crate::pac::timer::vals;
+use crate::peripherals;
 use crate::rcc::{self, SealedRccPeripheral};
 #[cfg(feature = "low-power")]
 use crate::rtc::Rtc;
 use crate::timer::{CoreInstance, GeneralInstance1Channel};
-use crate::{interrupt, peripherals};
 
 // NOTE regarding ALARM_COUNT:
 //
@@ -56,121 +56,6 @@ type T = peripherals::TIM23;
 #[cfg(time_driver_tim24)]
 type T = peripherals::TIM24;
 
-foreach_interrupt! {
-    (TIM1, timer, $block:ident, CC, $irq:ident) => {
-        #[cfg(time_driver_tim1)]
-        #[cfg(feature = "rt")]
-        #[interrupt]
-        fn $irq() {
-            DRIVER.on_interrupt()
-        }
-    };
-    (TIM2, timer, $block:ident, CC, $irq:ident) => {
-        #[cfg(time_driver_tim2)]
-        #[cfg(feature = "rt")]
-        #[interrupt]
-        fn $irq() {
-            DRIVER.on_interrupt()
-        }
-    };
-    (TIM3, timer, $block:ident, CC, $irq:ident) => {
-        #[cfg(time_driver_tim3)]
-        #[cfg(feature = "rt")]
-        #[interrupt]
-        fn $irq() {
-            DRIVER.on_interrupt()
-        }
-    };
-    (TIM4, timer, $block:ident, CC, $irq:ident) => {
-        #[cfg(time_driver_tim4)]
-        #[cfg(feature = "rt")]
-        #[interrupt]
-        fn $irq() {
-            DRIVER.on_interrupt()
-        }
-    };
-    (TIM5, timer, $block:ident, CC, $irq:ident) => {
-        #[cfg(time_driver_tim5)]
-        #[cfg(feature = "rt")]
-        #[interrupt]
-        fn $irq() {
-            DRIVER.on_interrupt()
-        }
-    };
-    (TIM8, timer, $block:ident, CC, $irq:ident) => {
-        #[cfg(time_driver_tim8)]
-        #[cfg(feature = "rt")]
-        #[interrupt]
-        fn $irq() {
-            DRIVER.on_interrupt()
-        }
-    };
-    (TIM9, timer, $block:ident, CC, $irq:ident) => {
-        #[cfg(time_driver_tim9)]
-        #[cfg(feature = "rt")]
-        #[interrupt]
-        fn $irq() {
-            DRIVER.on_interrupt()
-        }
-    };
-    (TIM12, timer, $block:ident, CC, $irq:ident) => {
-        #[cfg(time_driver_tim12)]
-        #[cfg(feature = "rt")]
-        #[interrupt]
-        fn $irq() {
-            DRIVER.on_interrupt()
-        }
-    };
-    (TIM15, timer, $block:ident, CC, $irq:ident) => {
-        #[cfg(time_driver_tim15)]
-        #[cfg(feature = "rt")]
-        #[interrupt]
-        fn $irq() {
-            DRIVER.on_interrupt()
-        }
-    };
-    (TIM20, timer, $block:ident, CC, $irq:ident) => {
-        #[cfg(time_driver_tim20)]
-        #[cfg(feature = "rt")]
-        #[interrupt]
-        fn $irq() {
-            DRIVER.on_interrupt()
-        }
-    };
-    (TIM21, timer, $block:ident, CC, $irq:ident) => {
-        #[cfg(time_driver_tim21)]
-        #[cfg(feature = "rt")]
-        #[interrupt]
-        fn $irq() {
-            DRIVER.on_interrupt()
-        }
-    };
-    (TIM22, timer, $block:ident, CC, $irq:ident) => {
-        #[cfg(time_driver_tim22)]
-        #[cfg(feature = "rt")]
-        #[interrupt]
-        fn $irq() {
-            DRIVER.on_interrupt()
-        }
-    };
-    (TIM23, timer, $block:ident, CC, $irq:ident) => {
-        #[cfg(time_driver_tim23)]
-        #[cfg(feature = "rt")]
-        #[interrupt]
-        fn $irq() {
-            DRIVER.on_interrupt()
-        }
-    };
-    (TIM24, timer, $block:ident, CC, $irq:ident) => {
-        #[cfg(time_driver_tim24)]
-        #[cfg(feature = "rt")]
-        #[interrupt]
-        fn $irq() {
-            DRIVER.on_interrupt()
-        }
-    };
-}
-
 fn regs_gp16() -> TimGp16 {
     unsafe { TimGp16::from_ptr(T::regs()) }
 }
@@ -282,7 +167,11 @@ impl RtcDriver {
         r.cnt().write(|w| w.set_cnt(self.saved_count.load(Ordering::SeqCst)));
 
         <T as GeneralInstance1Channel>::CaptureCompareInterrupt::unpend();
-        unsafe { <T as GeneralInstance1Channel>::CaptureCompareInterrupt::enable() };
+        <T as CoreInstance>::UpdateInterrupt::unpend();
+        unsafe {
+            <T as GeneralInstance1Channel>::CaptureCompareInterrupt::enable();
+            <T as CoreInstance>::UpdateInterrupt::enable();
+        }
     }
 
     fn init(&'static self, cs: CriticalSection) {
@@ -290,7 +179,7 @@ impl RtcDriver {
         regs_gp16().cr1().modify(|w| w.set_cen(true));
     }
 
-    fn on_interrupt(&self) {
+    pub(crate) fn on_interrupt(&self) {
         let r = regs_gp16();
 
         critical_section::with(|cs| {
@@ -508,7 +397,6 @@ impl Driver for RtcDriver {
     }
 }
 
-#[cfg(feature = "low-power")]
 pub(crate) const fn get_driver() -> &'static RtcDriver {
     &DRIVER
 }
diff --git a/embassy-stm32/src/usart/mod.rs b/embassy-stm32/src/usart/mod.rs
index 0e7da634d..8047d6005 100644
--- a/embassy-stm32/src/usart/mod.rs
+++ b/embassy-stm32/src/usart/mod.rs
@@ -491,6 +491,8 @@ impl<'d> UartTx<'d, Async> {
 
     /// Initiate an asynchronous UART write
     pub async fn write(&mut self, buffer: &[u8]) -> Result<(), Error> {
+        let _ = self.info.rcc.block_stop();
+
         let r = self.info.regs;
 
         half_duplex_set_rx_tx_before_write(&r, self.duplex == Duplex::Half(HalfDuplexReadback::Readback));
@@ -508,6 +510,8 @@ impl<'d> UartTx<'d, Async> {
 
     /// Wait until transmission complete
     pub async fn flush(&mut self) -> Result<(), Error> {
+        let _ = self.info.rcc.block_stop();
+
         flush(&self.info, &self.state).await
     }
 }
@@ -569,7 +573,7 @@ impl<'d, M: Mode> UartTx<'d, M> {
         let state = self.state;
         state.tx_rx_refcount.store(1, Ordering::Relaxed);
 
-        info.rcc.enable_and_reset();
+        info.rcc.enable_and_reset_without_stop();
 
         info.regs.cr3().modify(|w| {
             w.set_ctse(self.cts.is_some());
@@ -726,6 +730,8 @@ impl<'d> UartRx<'d, Async> {
 
     /// Initiate an asynchronous UART read
     pub async fn read(&mut self, buffer: &mut [u8]) -> Result<(), Error> {
+        let _ = self.info.rcc.block_stop();
+
         self.inner_read(buffer, false).await?;
 
         Ok(())
@@ -733,6 +739,8 @@ impl<'d> UartRx<'d, Async> {
 
     /// Initiate an asynchronous read with idle line detection enabled
     pub async fn read_until_idle(&mut self, buffer: &mut [u8]) -> Result<usize, Error> {
+        let _ = self.info.rcc.block_stop();
+
         self.inner_read(buffer, true).await
     }
 
@@ -1004,7 +1012,7 @@ impl<'d, M: Mode> UartRx<'d, M> {
             .eager_reads
             .store(config.eager_reads.unwrap_or(0), Ordering::Relaxed);
 
-        info.rcc.enable_and_reset();
+        info.rcc.enable_and_reset_without_stop();
 
         info.regs.cr3().write(|w| {
             w.set_rtse(self.rts.is_some());
@@ -1143,7 +1151,7 @@ fn drop_tx_rx(info: &Info, state: &State) {
         refcount == 1
     });
     if is_last_drop {
-        info.rcc.disable();
+        info.rcc.disable_without_stop();
     }
 }
 
@@ -1506,7 +1514,7 @@ impl<'d, M: Mode> Uart<'d, M> {
             .eager_reads
             .store(config.eager_reads.unwrap_or(0), Ordering::Relaxed);
 
-        info.rcc.enable_and_reset();
+        info.rcc.enable_and_reset_without_stop();
 
         info.regs.cr3().write(|w| {
             w.set_rtse(self.rx.rts.is_some());
diff --git a/embassy-stm32/src/usart/ringbuffered.rs b/embassy-stm32/src/usart/ringbuffered.rs
index bac570d27..cc5224b69 100644
--- a/embassy-stm32/src/usart/ringbuffered.rs
+++ b/embassy-stm32/src/usart/ringbuffered.rs
@@ -117,6 +117,8 @@ impl<'d> UartRx<'d, Async> {
         let rx = unsafe { self.rx.as_ref().map(|x| x.clone_unchecked()) };
         let rts = unsafe { self.rts.as_ref().map(|x| x.clone_unchecked()) };
 
+        info.rcc.increment_stop_refcount();
+
         // Don't disable the clock
         mem::forget(self);
 
@@ -324,6 +326,7 @@ impl<'d> RingBufferedUartRx<'d> {
 
 impl Drop for RingBufferedUartRx<'_> {
     fn drop(&mut self) {
+        self.info.rcc.decrement_stop_refcount();
         self.stop_uart();
         self.rx.as_ref().map(|x| x.set_as_disconnected());
         self.rts.as_ref().map(|x| x.set_as_disconnected());