Merge #842

842: WIP: Make unborrow safe to use r=Dirbaio a=GrantM11235

The basic idea is that `Unborrow::unborrow` is now safe to call and returns an `Unborrowed<'a, T>` which impls `Deref` and `DerefMut`

```rust
/// This is essentially a `&mut T`, but it is the size of `T` not the size
/// of a pointer. This is useful if T is a zero sized type.
pub struct Unborrowed<'a, T> {
    inner: T,
    _lifetime: PhantomData<&'a mut T>,
}
```

## Todo

- [x] Update other crates
  - [x] embassy-cortex-m
  - [x] embassy-hal-common
  - [x] embassy-lora
  - [x] embassy-nrf
  - [x] embassy-rp
  - [x] embassy-stm32
- [x] Remove usage of the unsafe `into_inner` method if possible
- [x] Review and amend docs for `Unborrow` and `Unborrowed`

Co-authored-by: Grant Miller <[email protected]>
Co-authored-by: Dario Nieuwenhuis <[email protected]>

65 files changed, 1527 insertions, 1421 deletions

diff --git a/embassy-cortex-m/src/interrupt.rs b/embassy-cortex-m/src/interrupt.rs
index 715f00381..7358caa46 100644
--- a/embassy-cortex-m/src/interrupt.rs
+++ b/embassy-cortex-m/src/interrupt.rs
@@ -3,7 +3,7 @@ use core::{mem, ptr};
 
 use atomic_polyfill::{compiler_fence, AtomicPtr, Ordering};
 use cortex_m::peripheral::NVIC;
-use embassy_hal_common::Unborrow;
+use embassy_hal_common::Peripheral;
 pub use embassy_macros::cortex_m_interrupt_take as take;
 
 /// Implementation detail, do not use outside embassy crates.
@@ -32,7 +32,7 @@ unsafe impl cortex_m::interrupt::InterruptNumber for NrWrap {
 
 /// Represents an interrupt type that can be configured by embassy to handle
 /// interrupts.
-pub unsafe trait Interrupt: Unborrow<Target = Self> {
+pub unsafe trait Interrupt: Peripheral<P = Self> {
     /// Return the NVIC interrupt number for this interrupt.
     fn number(&self) -> u16;
     /// Steal an instance of this interrupt
diff --git a/embassy-cortex-m/src/peripheral.rs b/embassy-cortex-m/src/peripheral.rs
index 6a03bfb9f..e2f295579 100644
--- a/embassy-cortex-m/src/peripheral.rs
+++ b/embassy-cortex-m/src/peripheral.rs
@@ -1,9 +1,9 @@
 //! Peripheral interrupt handling specific to cortex-m devices.
-use core::marker::PhantomData;
 use core::mem::MaybeUninit;
 
 use cortex_m::peripheral::scb::VectActive;
 use cortex_m::peripheral::{NVIC, SCB};
+use embassy_hal_common::{into_ref, Peripheral, PeripheralRef};
 
 use crate::interrupt::{Interrupt, InterruptExt, Priority};
 
@@ -33,8 +33,7 @@ impl<S> StateStorage<S> {
 /// a safe way.
 pub struct PeripheralMutex<'a, S: PeripheralState> {
     state: *mut S,
-    _phantom: PhantomData<&'a mut S>,
-    irq: S::Interrupt,
+    irq: PeripheralRef<'a, S::Interrupt>,
 }
 
 /// Whether `irq` can be preempted by the current interrupt.
@@ -62,8 +61,14 @@ impl<'a, S: PeripheralState> PeripheralMutex<'a, S> {
     /// Create a new `PeripheralMutex` wrapping `irq`, with `init` initializing the initial state.
     ///
     /// Registers `on_interrupt` as the `irq`'s handler, and enables it.
-    pub fn new(irq: S::Interrupt, storage: &'a mut StateStorage<S>, init: impl FnOnce() -> S) -> Self {
-        if can_be_preempted(&irq) {
+    pub fn new(
+        irq: impl Peripheral<P = S::Interrupt> + 'a,
+        storage: &'a mut StateStorage<S>,
+        init: impl FnOnce() -> S,
+    ) -> Self {
+        into_ref!(irq);
+
+        if can_be_preempted(&*irq) {
             panic!(
                 "`PeripheralMutex` cannot be created in an interrupt with higher priority than the interrupt it wraps"
             );
@@ -88,11 +93,7 @@ impl<'a, S: PeripheralState> PeripheralMutex<'a, S> {
         irq.set_handler_context(state_ptr as *mut ());
         irq.enable();
 
-        Self {
-            irq,
-            state: state_ptr,
-            _phantom: PhantomData,
-        }
+        Self { irq, state: state_ptr }
     }
 
     /// Access the peripheral state ensuring interrupts are disabled so that the state can be
diff --git a/embassy-hal-common/src/lib.rs b/embassy-hal-common/src/lib.rs
index c8cf1c4cd..d3d9e0a84 100644
--- a/embassy-hal-common/src/lib.rs
+++ b/embassy-hal-common/src/lib.rs
@@ -6,10 +6,10 @@ pub(crate) mod fmt;
 
 pub mod drop;
 mod macros;
+mod peripheral;
 pub mod ratio;
 pub mod ring_buffer;
-mod unborrow;
-pub use unborrow::Unborrow;
+pub use peripheral::{Peripheral, PeripheralRef};
 
 /// Low power blocking wait loop using WFE/SEV.
 pub fn low_power_wait_until(mut condition: impl FnMut() -> bool) {
diff --git a/embassy-hal-common/src/macros.rs b/embassy-hal-common/src/macros.rs
index ffa5e4fb6..7af85f782 100644
--- a/embassy-hal-common/src/macros.rs
+++ b/embassy-hal-common/src/macros.rs
@@ -21,13 +21,7 @@ macro_rules! peripherals {
                 }
 
                 $(#[$cfg])?
-                unsafe impl $crate::Unborrow for $name {
-                    type Target = $name;
-                    #[inline]
-                    unsafe fn unborrow(self) -> $name {
-                        self
-                    }
-                }
+                $crate::impl_peripheral!($name);
             )*
         }
 
@@ -77,22 +71,23 @@ macro_rules! peripherals {
 }
 
 #[macro_export]
-macro_rules! unborrow {
+macro_rules! into_ref {
     ($($name:ident),*) => {
         $(
-            let mut $name = unsafe { $name.unborrow() };
+            let mut $name = $name.into_ref();
         )*
     }
 }
 
 #[macro_export]
-macro_rules! unsafe_impl_unborrow {
+macro_rules! impl_peripheral {
     ($type:ident) => {
-        unsafe impl $crate::Unborrow for $type {
-            type Target = $type;
+        impl $crate::Peripheral for $type {
+            type P = $type;
+
             #[inline]
-            unsafe fn unborrow(self) -> Self::Target {
-                self
+            unsafe fn clone_unchecked(&mut self) -> Self::P {
+                $type { ..*self }
             }
         }
     };
diff --git a/embassy-hal-common/src/peripheral.rs b/embassy-hal-common/src/peripheral.rs
new file mode 100644
index 000000000..038cebb5e
--- /dev/null
+++ b/embassy-hal-common/src/peripheral.rs
@@ -0,0 +1,173 @@
+use core::marker::PhantomData;
+use core::ops::{Deref, DerefMut};
+
+/// An exclusive reference to a peripheral.
+///
+/// This is functionally the same as a `&'a mut T`. The reason for having a
+/// dedicated struct is memory efficiency:
+///
+/// Peripheral singletons are typically either zero-sized (for concrete peripehrals
+/// like `PA9` or `Spi4`) or very small (for example `AnyPin` which is 1 byte).
+/// However `&mut T` is always 4 bytes for 32-bit targets, even if T is zero-sized.
+/// PeripheralRef stores a copy of `T` instead, so it's the same size.
+///
+/// but it is the size of `T` not the size
+/// of a pointer. This is useful if T is a zero sized type.
+pub struct PeripheralRef<'a, T> {
+    inner: T,
+    _lifetime: PhantomData<&'a mut T>,
+}
+
+impl<'a, T> PeripheralRef<'a, T> {
+    #[inline]
+    pub fn new(inner: T) -> Self {
+        Self {
+            inner,
+            _lifetime: PhantomData,
+        }
+    }
+
+    /// Unsafely clone (duplicate) a peripheral singleton.
+    ///
+    /// # Safety
+    ///
+    /// This returns an owned clone of the peripheral. You must manually ensure
+    /// only one copy of the peripheral is in use at a time. For example, don't
+    /// create two SPI drivers on `SPI1`, because they will "fight" each other.
+    ///
+    /// You should strongly prefer using `reborrow()` instead. It returns a
+    /// `PeripheralRef` that borrows `self`, which allows the borrow checker
+    /// to enforce this at compile time.
+    pub unsafe fn clone_unchecked(&mut self) -> PeripheralRef<'a, T>
+    where
+        T: Peripheral<P = T>,
+    {
+        PeripheralRef::new(self.inner.clone_unchecked())
+    }
+
+    /// Reborrow into a "child" PeripheralRef.
+    ///
+    /// `self` will stay borrowed until the child PeripheralRef is dropped.
+    pub fn reborrow(&mut self) -> PeripheralRef<'_, T>
+    where
+        T: Peripheral<P = T>,
+    {
+        // safety: we're returning the clone inside a new PeripheralRef that borrows
+        // self, so user code can't use both at the same time.
+        PeripheralRef::new(unsafe { self.inner.clone_unchecked() })
+    }
+
+    /// Map the inner peripheral using `Into`.
+    ///
+    /// This converts from `PeripheralRef<'a, T>` to `PeripheralRef<'a, U>`, using an
+    /// `Into` impl to convert from `T` to `U`.
+    ///
+    /// For example, this can be useful to degrade GPIO pins: converting from PeripheralRef<'a, PB11>` to `PeripheralRef<'a, AnyPin>`.
+    #[inline]
+    pub fn map_into<U>(self) -> PeripheralRef<'a, U>
+    where
+        T: Into<U>,
+    {
+        PeripheralRef {
+            inner: self.inner.into(),
+            _lifetime: PhantomData,
+        }
+    }
+}
+
+impl<'a, T> Deref for PeripheralRef<'a, T> {
+    type Target = T;
+
+    #[inline]
+    fn deref(&self) -> &Self::Target {
+        &self.inner
+    }
+}
+
+impl<'a, T> DerefMut for PeripheralRef<'a, T> {
+    #[inline]
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.inner
+    }
+}
+
+/// Trait for any type that can be used as a peripheral of type `P`.
+///
+/// This is used in driver constructors, to allow passing either owned peripherals (e.g. `TWISPI0`),
+/// or borrowed peripherals (e.g. `&mut TWISPI0`).
+///
+/// For example, if you have a driver with a constructor like this:
+///
+/// ```ignore
+/// impl<'d, T: Instance> Twim<'d, T> {
+///     pub fn new(
+///         twim: impl Peripheral<P = T> + 'd,
+///         irq: impl Peripheral<P = T::Interrupt> + 'd,
+///         sda: impl Peripheral<P = impl GpioPin> + 'd,
+///         scl: impl Peripheral<P = impl GpioPin> + 'd,
+///         config: Config,
+///     ) -> Self { .. }
+/// }
+/// ```
+///
+/// You may call it with owned peripherals, which yields an instance that can live forever (`'static`):
+///
+/// ```ignore
+/// let mut twi: Twim<'static, ...> = Twim::new(p.TWISPI0, irq, p.P0_03, p.P0_04, config);
+/// ```
+///
+/// Or you may call it with borrowed peripherals, which yields an instance that can only live for as long
+/// as the borrows last:
+///
+/// ```ignore
+/// let mut twi: Twim<'_, ...> = Twim::new(&mut p.TWISPI0, &mut irq, &mut p.P0_03, &mut p.P0_04, config);
+/// ```
+///
+/// # Implementation details, for HAL authors
+///
+/// When writing a HAL, the intended way to use this trait is to take `impl Peripheral<P = ..>` in
+/// the HAL's public API (such as driver constructors), calling `.into_ref()` to obtain a `PeripheralRef`,
+/// and storing that in the driver struct.
+///
+/// `.into_ref()` on an owned `T` yields a `PeripheralRef<'static, T>`.
+/// `.into_ref()` on an `&'a mut T` yields a `PeripheralRef<'a, T>`.
+pub trait Peripheral: Sized {
+    /// Peripheral singleton type
+    type P;
+
+    /// Unsafely clone (duplicate) a peripheral singleton.
+    ///
+    /// # Safety
+    ///
+    /// This returns an owned clone of the peripheral. You must manually ensure
+    /// only one copy of the peripheral is in use at a time. For example, don't
+    /// create two SPI drivers on `SPI1`, because they will "fight" each other.
+    ///
+    /// You should strongly prefer using `into_ref()` instead. It returns a
+    /// `PeripheralRef`, which allows the borrow checker to enforce this at compile time.
+    unsafe fn clone_unchecked(&mut self) -> Self::P;
+
+    /// Convert a value into a `PeripheralRef`.
+    ///
+    /// When called on an owned `T`, yields a `PeripheralRef<'static, T>`.
+    /// When called on an `&'a mut T`, yields a `PeripheralRef<'a, T>`.
+    #[inline]
+    fn into_ref<'a>(mut self) -> PeripheralRef<'a, Self::P>
+    where
+        Self: 'a,
+    {
+        PeripheralRef::new(unsafe { self.clone_unchecked() })
+    }
+}
+
+impl<'b, T: DerefMut> Peripheral for T
+where
+    T::Target: Peripheral,
+{
+    type P = <T::Target as Peripheral>::P;
+
+    #[inline]
+    unsafe fn clone_unchecked(&mut self) -> Self::P {
+        self.deref_mut().clone_unchecked()
+    }
+}
diff --git a/embassy-hal-common/src/unborrow.rs b/embassy-hal-common/src/unborrow.rs
deleted file mode 100644
index dacfa3d42..000000000
--- a/embassy-hal-common/src/unborrow.rs
+++ /dev/null
@@ -1,60 +0,0 @@
-/// Unsafely unborrow an owned singleton out of a `&mut`.
-///
-/// It is intended to be implemented for owned peripheral singletons, such as `USART3` or `AnyPin`.
-/// Unborrowing an owned `T` yields the same `T`. Unborrowing a `&mut T` yields a copy of the T.
-///
-/// This allows writing HAL drivers that either own or borrow their peripherals, but that don't have
-/// to store pointers in the borrowed case.
-///
-/// Safety: this trait can be used to copy non-Copy types. Implementors must not cause
-/// immediate UB when copied, and must not cause UB when copies are later used, provided they
-/// are only used according the [`Self::unborrow`] safety contract.
-///
-pub unsafe trait Unborrow {
-    /// Unborrow result type
-    type Target;
-
-    /// Unborrow a value.
-    ///
-    /// Safety: This returns a copy of a singleton that's normally not
-    /// copiable. The returned copy must ONLY be used while the lifetime of `self` is
-    /// valid, as if it were accessed through `self` every time.
-    unsafe fn unborrow(self) -> Self::Target;
-}
-
-unsafe impl<'a, T: Unborrow> Unborrow for &'a mut T {
-    type Target = T::Target;
-    unsafe fn unborrow(self) -> Self::Target {
-        T::unborrow(core::ptr::read(self))
-    }
-}
-
-macro_rules! unsafe_impl_unborrow_tuples {
-    ($($t:ident),+) => {
-        unsafe impl<$($t),+> Unborrow for ($($t),+)
-        where
-            $(
-                $t: Unborrow<Target = $t>
-            ),+
-        {
-            type Target = ($($t),+);
-            unsafe fn unborrow(self) -> Self::Target {
-                self
-            }
-        }
-
-
-    };
-}
-
-unsafe_impl_unborrow_tuples!(A, B);
-unsafe_impl_unborrow_tuples!(A, B, C);
-unsafe_impl_unborrow_tuples!(A, B, C, D);
-unsafe_impl_unborrow_tuples!(A, B, C, D, E);
-unsafe_impl_unborrow_tuples!(A, B, C, D, E, F);
-unsafe_impl_unborrow_tuples!(A, B, C, D, E, F, G);
-unsafe_impl_unborrow_tuples!(A, B, C, D, E, F, G, H);
-unsafe_impl_unborrow_tuples!(A, B, C, D, E, F, G, H, I);
-unsafe_impl_unborrow_tuples!(A, B, C, D, E, F, G, H, I, J);
-unsafe_impl_unborrow_tuples!(A, B, C, D, E, F, G, H, I, J, K);
-unsafe_impl_unborrow_tuples!(A, B, C, D, E, F, G, H, I, J, K, L);
diff --git a/embassy-lora/src/stm32wl/mod.rs b/embassy-lora/src/stm32wl/mod.rs
index d7d399692..b0d101b77 100644
--- a/embassy-lora/src/stm32wl/mod.rs
+++ b/embassy-lora/src/stm32wl/mod.rs
@@ -3,7 +3,7 @@ use core::future::Future;
 use core::mem::MaybeUninit;
 
 use embassy::channel::signal::Signal;
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 use embassy_stm32::dma::NoDma;
 use embassy_stm32::gpio::{AnyPin, Output};
 use embassy_stm32::interrupt::{InterruptExt, SUBGHZ_RADIO};
@@ -12,7 +12,7 @@ use embassy_stm32::subghz::{
     LoRaSyncWord, Ocp, PaConfig, PaSel, PacketType, RampTime, RegMode, RfFreq, SpreadingFactor as SF, StandbyClk,
     Status, SubGhz, TcxoMode, TcxoTrim, Timeout, TxParams,
 };
-use embassy_stm32::Unborrow;
+use embassy_stm32::Peripheral;
 use lorawan_device::async_device::radio::{Bandwidth, PhyRxTx, RfConfig, RxQuality, SpreadingFactor, TxConfig};
 use lorawan_device::async_device::Timings;
 
@@ -30,37 +30,37 @@ pub struct RadioError;
 
 static IRQ: Signal<(Status, u16)> = Signal::new();
 
-struct StateInner<'a> {
-    radio: SubGhz<'a, NoDma, NoDma>,
-    switch: RadioSwitch<'a>,
+struct StateInner<'d> {
+    radio: SubGhz<'d, NoDma, NoDma>,
+    switch: RadioSwitch<'d>,
 }
 
 /// External state storage for the radio state
 pub struct SubGhzState<'a>(MaybeUninit<StateInner<'a>>);
-impl<'a> SubGhzState<'a> {
+impl<'d> SubGhzState<'d> {
     pub const fn new() -> Self {
         Self(MaybeUninit::uninit())
     }
 }
 
 /// The radio peripheral keeping the radio state and owning the radio IRQ.
-pub struct SubGhzRadio<'a> {
-    state: *mut StateInner<'a>,
-    _irq: SUBGHZ_RADIO,
+pub struct SubGhzRadio<'d> {
+    state: *mut StateInner<'d>,
+    _irq: PeripheralRef<'d, SUBGHZ_RADIO>,
 }
 
-impl<'a> SubGhzRadio<'a> {
+impl<'d> SubGhzRadio<'d> {
     /// Create a new instance of a SubGhz radio for LoRaWAN.
     ///
     /// # Safety
     /// Do not leak self or futures
     pub unsafe fn new(
-        state: &'a mut SubGhzState<'a>,
-        radio: SubGhz<'a, NoDma, NoDma>,
-        switch: RadioSwitch<'a>,
-        irq: impl Unborrow<Target = SUBGHZ_RADIO>,
+        state: &'d mut SubGhzState<'d>,
+        radio: SubGhz<'d, NoDma, NoDma>,
+        switch: RadioSwitch<'d>,
+        irq: impl Peripheral<P = SUBGHZ_RADIO> + 'd,
     ) -> Self {
-        unborrow!(irq);
+        into_ref!(irq);
 
         let mut inner = StateInner { radio, switch };
         inner.radio.reset();
@@ -73,7 +73,7 @@ impl<'a> SubGhzRadio<'a> {
             // This is safe because we only get interrupts when configured for, so
             // the radio will be awaiting on the signal at this point. If not, the ISR will
             // anyway only adjust the state in the IRQ signal state.
-            let state = &mut *(p as *mut StateInner<'a>);
+            let state = &mut *(p as *mut StateInner<'d>);
             state.on_interrupt();
         });
         irq.set_handler_context(state_ptr as *mut ());
@@ -86,7 +86,7 @@ impl<'a> SubGhzRadio<'a> {
     }
 }
 
-impl<'a> StateInner<'a> {
+impl<'d> StateInner<'d> {
     /// Configure radio settings in preparation for TX or RX
     pub(crate) fn configure(&mut self) -> Result<(), RadioError> {
         trace!("Configuring STM32WL SUBGHZ radio");
@@ -272,13 +272,13 @@ impl PhyRxTx for SubGhzRadio<'static> {
     }
 }
 
-impl<'a> From<embassy_stm32::spi::Error> for RadioError {
+impl From<embassy_stm32::spi::Error> for RadioError {
     fn from(_: embassy_stm32::spi::Error) -> Self {
         RadioError
     }
 }
 
-impl<'a> Timings for SubGhzRadio<'a> {
+impl<'d> Timings for SubGhzRadio<'d> {
     fn get_rx_window_offset_ms(&self) -> i32 {
         -200
     }
@@ -288,14 +288,14 @@ impl<'a> Timings for SubGhzRadio<'a> {
 }
 
 /// Represents the radio switch found on STM32WL based boards, used to control the radio for transmission or reception.
-pub struct RadioSwitch<'a> {
-    ctrl1: Output<'a, AnyPin>,
-    ctrl2: Output<'a, AnyPin>,
-    ctrl3: Output<'a, AnyPin>,
+pub struct RadioSwitch<'d> {
+    ctrl1: Output<'d, AnyPin>,
+    ctrl2: Output<'d, AnyPin>,
+    ctrl3: Output<'d, AnyPin>,
 }
 
-impl<'a> RadioSwitch<'a> {
-    pub fn new(ctrl1: Output<'a, AnyPin>, ctrl2: Output<'a, AnyPin>, ctrl3: Output<'a, AnyPin>) -> Self {
+impl<'d> RadioSwitch<'d> {
+    pub fn new(ctrl1: Output<'d, AnyPin>, ctrl2: Output<'d, AnyPin>, ctrl3: Output<'d, AnyPin>) -> Self {
         Self { ctrl1, ctrl2, ctrl3 }
     }
 
diff --git a/embassy-macros/src/macros/cortex_m_interrupt_declare.rs b/embassy-macros/src/macros/cortex_m_interrupt_declare.rs
index eeed5d483..ab61ad5da 100644
--- a/embassy-macros/src/macros/cortex_m_interrupt_declare.rs
+++ b/embassy-macros/src/macros/cortex_m_interrupt_declare.rs
@@ -25,12 +25,7 @@ pub fn run(name: syn::Ident) -> Result<TokenStream, TokenStream> {
             }
         }
 
-        unsafe impl ::embassy_hal_common::Unborrow for #name_interrupt {
-            type Target = #name_interrupt;
-            unsafe fn unborrow(self) -> #name_interrupt {
-                self
-            }
-        }
+        ::embassy_hal_common::impl_peripheral!(#name_interrupt);
     };
     Ok(result)
 }
diff --git a/embassy-nrf/src/buffered_uarte.rs b/embassy-nrf/src/buffered_uarte.rs
index 4fc78b95d..89c1ba908 100644
--- a/embassy-nrf/src/buffered_uarte.rs
+++ b/embassy-nrf/src/buffered_uarte.rs
@@ -15,14 +15,13 @@
 
 use core::cmp::min;
 use core::future::Future;
-use core::marker::PhantomData;
 use core::sync::atomic::{compiler_fence, Ordering};
 use core::task::Poll;
 
 use embassy::waitqueue::WakerRegistration;
 use embassy_cortex_m::peripheral::{PeripheralMutex, PeripheralState, StateStorage};
 use embassy_hal_common::ring_buffer::RingBuffer;
-use embassy_hal_common::{low_power_wait_until, unborrow};
+use embassy_hal_common::{into_ref, low_power_wait_until, PeripheralRef};
 use futures::future::poll_fn;
 // Re-export SVD variants to allow user to directly set values
 pub use pac::uarte0::{baudrate::BAUDRATE_A as Baudrate, config::PARITY_A as Parity};
@@ -32,7 +31,7 @@ use crate::interrupt::InterruptExt;
 use crate::ppi::{AnyConfigurableChannel, ConfigurableChannel, Event, Ppi, Task};
 use crate::timer::{Frequency, Instance as TimerInstance, Timer};
 use crate::uarte::{apply_workaround_for_enable_anomaly, Config, Instance as UarteInstance};
-use crate::{pac, Unborrow};
+use crate::{pac, Peripheral};
 
 #[derive(Copy, Clone, Debug, PartialEq)]
 enum RxState {
@@ -54,7 +53,7 @@ impl<'d, U: UarteInstance, T: TimerInstance> State<'d, U, T> {
 }
 
 struct StateInner<'d, U: UarteInstance, T: TimerInstance> {
-    phantom: PhantomData<&'d mut U>,
+    _peri: PeripheralRef<'d, U>,
     timer: Timer<'d, T>,
     _ppi_ch1: Ppi<'d, AnyConfigurableChannel, 1, 2>,
     _ppi_ch2: Ppi<'d, AnyConfigurableChannel, 1, 1>,
@@ -78,20 +77,20 @@ impl<'d, U: UarteInstance, T: TimerInstance> Unpin for BufferedUarte<'d, U, T> {
 impl<'d, U: UarteInstance, T: TimerInstance> BufferedUarte<'d, U, T> {
     pub fn new(
         state: &'d mut State<'d, U, T>,
-        _uarte: impl Unborrow<Target = U> + 'd,
-        timer: impl Unborrow<Target = T> + 'd,
-        ppi_ch1: impl Unborrow<Target = impl ConfigurableChannel + 'd> + 'd,
-        ppi_ch2: impl Unborrow<Target = impl ConfigurableChannel + 'd> + 'd,
-        irq: impl Unborrow<Target = U::Interrupt> + 'd,
-        rxd: impl Unborrow<Target = impl GpioPin> + 'd,
-        txd: impl Unborrow<Target = impl GpioPin> + 'd,
-        cts: impl Unborrow<Target = impl GpioPin> + 'd,
-        rts: impl Unborrow<Target = impl GpioPin> + 'd,
+        peri: impl Peripheral<P = U> + 'd,
+        timer: impl Peripheral<P = T> + 'd,
+        ppi_ch1: impl Peripheral<P = impl ConfigurableChannel + 'd> + 'd,
+        ppi_ch2: impl Peripheral<P = impl ConfigurableChannel + 'd> + 'd,
+        irq: impl Peripheral<P = U::Interrupt> + 'd,
+        rxd: impl Peripheral<P = impl GpioPin> + 'd,
+        txd: impl Peripheral<P = impl GpioPin> + 'd,
+        cts: impl Peripheral<P = impl GpioPin> + 'd,
+        rts: impl Peripheral<P = impl GpioPin> + 'd,
         config: Config,
         rx_buffer: &'d mut [u8],
         tx_buffer: &'d mut [u8],
     ) -> Self {
-        unborrow!(ppi_ch1, ppi_ch2, irq, rxd, txd, cts, rts);
+        into_ref!(peri, ppi_ch1, ppi_ch2, irq, rxd, txd, cts, rts);
 
         let r = U::regs();
 
@@ -147,7 +146,7 @@ impl<'d, U: UarteInstance, T: TimerInstance> BufferedUarte<'d, U, T> {
         timer.cc(0).short_compare_stop();
 
         let mut ppi_ch1 = Ppi::new_one_to_two(
-            ppi_ch1.degrade(),
+            ppi_ch1.map_into(),
             Event::from_reg(&r.events_rxdrdy),
             timer.task_clear(),
             timer.task_start(),
@@ -155,7 +154,7 @@ impl<'d, U: UarteInstance, T: TimerInstance> BufferedUarte<'d, U, T> {
         ppi_ch1.enable();
 
         let mut ppi_ch2 = Ppi::new_one_to_one(
-            ppi_ch2.degrade(),
+            ppi_ch2.map_into(),
             timer.cc(0).event_compare(),
             Task::from_reg(&r.tasks_stoprx),
         );
@@ -163,7 +162,7 @@ impl<'d, U: UarteInstance, T: TimerInstance> BufferedUarte<'d, U, T> {
 
         Self {
             inner: PeripheralMutex::new(irq, &mut state.0, move || StateInner {
-                phantom: PhantomData,
+                _peri: peri,
                 timer,
                 _ppi_ch1: ppi_ch1,
                 _ppi_ch2: ppi_ch2,
diff --git a/embassy-nrf/src/gpio.rs b/embassy-nrf/src/gpio.rs
index fd4ae2ec3..a61ff6aa5 100644
--- a/embassy-nrf/src/gpio.rs
+++ b/embassy-nrf/src/gpio.rs
@@ -2,15 +2,14 @@
 
 use core::convert::Infallible;
 use core::hint::unreachable_unchecked;
-use core::marker::PhantomData;
 
 use cfg_if::cfg_if;
-use embassy_hal_common::{unborrow, unsafe_impl_unborrow};
+use embassy_hal_common::{impl_peripheral, into_ref, PeripheralRef};
 
 use self::sealed::Pin as _;
 use crate::pac::p0 as gpio;
 use crate::pac::p0::pin_cnf::{DRIVE_A, PULL_A};
-use crate::{pac, Unborrow};
+use crate::{pac, Peripheral};
 
 /// A GPIO port with up to 32 pins.
 #[derive(Debug, Eq, PartialEq)]
@@ -39,7 +38,7 @@ pub struct Input<'d, T: Pin> {
 
 impl<'d, T: Pin> Input<'d, T> {
     #[inline]
-    pub fn new(pin: impl Unborrow<Target = T> + 'd, pull: Pull) -> Self {
+    pub fn new(pin: impl Peripheral<P = T> + 'd, pull: Pull) -> Self {
         let mut pin = Flex::new(pin);
         pin.set_as_input(pull);
 
@@ -119,7 +118,7 @@ pub struct Output<'d, T: Pin> {
 
 impl<'d, T: Pin> Output<'d, T> {
     #[inline]
-    pub fn new(pin: impl Unborrow<Target = T> + 'd, initial_output: Level, drive: OutputDrive) -> Self {
+    pub fn new(pin: impl Peripheral<P = T> + 'd, initial_output: Level, drive: OutputDrive) -> Self {
         let mut pin = Flex::new(pin);
         match initial_output {
             Level::High => pin.set_high(),
@@ -194,8 +193,7 @@ fn convert_pull(pull: Pull) -> PULL_A {
 /// set while not in output mode, so the pin's level will be 'remembered' when it is not in output
 /// mode.
 pub struct Flex<'d, T: Pin> {
-    pub(crate) pin: T,
-    phantom: PhantomData<&'d mut T>,
+    pub(crate) pin: PeripheralRef<'d, T>,
 }
 
 impl<'d, T: Pin> Flex<'d, T> {
@@ -204,13 +202,10 @@ impl<'d, T: Pin> Flex<'d, T> {
     /// The pin remains disconnected. The initial output level is unspecified, but can be changed
     /// before the pin is put into output mode.
     #[inline]
-    pub fn new(pin: impl Unborrow<Target = T> + 'd) -> Self {
-        unborrow!(pin);
+    pub fn new(pin: impl Peripheral<P = T> + 'd) -> Self {
+        into_ref!(pin);
         // Pin will be in disconnected state.
-        Self {
-            pin,
-            phantom: PhantomData,
-        }
+        Self { pin }
     }
 
     /// Put the pin into input mode.
@@ -379,7 +374,7 @@ pub(crate) mod sealed {
     }
 }
 
-pub trait Pin: Unborrow<Target = Self> + sealed::Pin + Sized + 'static {
+pub trait Pin: Peripheral<P = Self> + Into<AnyPin> + sealed::Pin + Sized + 'static {
     /// Number of the pin within the port (0..31)
     #[inline]
     fn pin(&self) -> u8 {
@@ -423,7 +418,7 @@ impl AnyPin {
     }
 }
 
-unsafe_impl_unborrow!(AnyPin);
+impl_peripheral!(AnyPin);
 impl Pin for AnyPin {}
 impl sealed::Pin for AnyPin {
     #[inline]
@@ -438,10 +433,13 @@ pub(crate) trait PselBits {
     fn psel_bits(&self) -> u32;
 }
 
-impl PselBits for Option<AnyPin> {
+impl<'a, P: Pin> PselBits for Option<PeripheralRef<'a, P>> {
     #[inline]
     fn psel_bits(&self) -> u32 {
-        self.as_ref().map_or(1u32 << 31, Pin::psel_bits)
+        match self {
+            Some(pin) => pin.psel_bits(),
+            None => 1u32 << 31,
+        }
     }
 }
 
@@ -463,6 +461,12 @@ macro_rules! impl_pin {
                 $port_num * 32 + $pin_num
             }
         }
+
+        impl From<peripherals::$type> for crate::gpio::AnyPin {
+            fn from(val: peripherals::$type) -> Self {
+                crate::gpio::Pin::degrade(val)
+            }
+        }
     };
 }
 
diff --git a/embassy-nrf/src/gpiote.rs b/embassy-nrf/src/gpiote.rs
index d4e1cb35c..cef80ae0a 100644
--- a/embassy-nrf/src/gpiote.rs
+++ b/embassy-nrf/src/gpiote.rs
@@ -1,10 +1,9 @@
 use core::convert::Infallible;
 use core::future::Future;
-use core::marker::PhantomData;
 use core::task::{Context, Poll};
 
 use embassy::waitqueue::AtomicWaker;
-use embassy_hal_common::unsafe_impl_unborrow;
+use embassy_hal_common::{impl_peripheral, Peripheral, PeripheralRef};
 use futures::future::poll_fn;
 
 use crate::gpio::sealed::Pin as _;
@@ -301,16 +300,22 @@ impl<'d, C: Channel, T: GpioPin> OutputChannel<'d, C, T> {
 // =======================
 
 pub(crate) struct PortInputFuture<'a> {
-    pin_port: u8,
-    phantom: PhantomData<&'a mut AnyPin>,
+    pin: PeripheralRef<'a, AnyPin>,
+}
+
+impl<'a> PortInputFuture<'a> {
+    fn new(pin: impl Peripheral<P = impl GpioPin> + 'a) -> Self {
+        Self {
+            pin: pin.into_ref().map_into(),
+        }
+    }
 }
 
 impl<'a> Unpin for PortInputFuture<'a> {}
 
 impl<'a> Drop for PortInputFuture<'a> {
     fn drop(&mut self) {
-        let pin = unsafe { AnyPin::steal(self.pin_port) };
-        pin.conf().modify(|_, w| w.sense().disabled());
+        self.pin.conf().modify(|_, w| w.sense().disabled());
     }
 }
 
@@ -318,10 +323,9 @@ impl<'a> Future for PortInputFuture<'a> {
     type Output = ();
 
     fn poll(self: core::pin::Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        PORT_WAKERS[self.pin_port as usize].register(cx.waker());
+        PORT_WAKERS[self.pin.pin_port() as usize].register(cx.waker());
 
-        let pin = unsafe { AnyPin::steal(self.pin_port) };
-        if pin.conf().read().sense().is_disabled() {
+        if self.pin.conf().read().sense().is_disabled() {
             Poll::Ready(())
         } else {
             Poll::Pending
@@ -354,22 +358,12 @@ impl<'d, T: GpioPin> Input<'d, T> {
 impl<'d, T: GpioPin> Flex<'d, T> {
     pub async fn wait_for_high(&mut self) {
         self.pin.conf().modify(|_, w| w.sense().high());
-
-        PortInputFuture {
-            pin_port: self.pin.pin_port(),
-            phantom: PhantomData,
-        }
-        .await
+        PortInputFuture::new(&mut self.pin).await
     }
 
     pub async fn wait_for_low(&mut self) {
         self.pin.conf().modify(|_, w| w.sense().low());
-
-        PortInputFuture {
-            pin_port: self.pin.pin_port(),
-            phantom: PhantomData,
-        }
-        .await
+        PortInputFuture::new(&mut self.pin).await
     }
 
     pub async fn wait_for_rising_edge(&mut self) {
@@ -388,11 +382,7 @@ impl<'d, T: GpioPin> Flex<'d, T> {
         } else {
             self.pin.conf().modify(|_, w| w.sense().high());
         }
-        PortInputFuture {
-            pin_port: self.pin.pin_port(),
-            phantom: PhantomData,
-        }
-        .await
+        PortInputFuture::new(&mut self.pin).await
     }
 }
 
@@ -414,7 +404,7 @@ pub trait Channel: sealed::Channel + Sized {
 pub struct AnyChannel {
     number: u8,
 }
-unsafe_impl_unborrow!(AnyChannel);
+impl_peripheral!(AnyChannel);
 impl sealed::Channel for AnyChannel {}
 impl Channel for AnyChannel {
     fn number(&self) -> usize {
diff --git a/embassy-nrf/src/lib.rs b/embassy-nrf/src/lib.rs
index 3699ad0fa..ad6c16c1f 100644
--- a/embassy-nrf/src/lib.rs
+++ b/embassy-nrf/src/lib.rs
@@ -135,7 +135,7 @@ pub use chip::pac;
 pub(crate) use chip::pac;
 pub use chip::{peripherals, Peripherals};
 pub use embassy_cortex_m::executor;
-pub use embassy_hal_common::{unborrow, Unborrow};
+pub use embassy_hal_common::{into_ref, Peripheral, PeripheralRef};
 pub use embassy_macros::cortex_m_interrupt as interrupt;
 
 pub mod config {
diff --git a/embassy-nrf/src/nvmc.rs b/embassy-nrf/src/nvmc.rs
index e350f8c99..cd6100339 100644
--- a/embassy-nrf/src/nvmc.rs
+++ b/embassy-nrf/src/nvmc.rs
@@ -1,15 +1,14 @@
 //! Nvmcerature sensor interface.
 
-use core::marker::PhantomData;
 use core::{ptr, slice};
 
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 use embedded_storage::nor_flash::{
     ErrorType, MultiwriteNorFlash, NorFlash, NorFlashError, NorFlashErrorKind, ReadNorFlash,
 };
 
 use crate::peripherals::NVMC;
-use crate::{pac, Unborrow};
+use crate::{pac, Peripheral};
 
 pub const PAGE_SIZE: usize = 4096;
 pub const FLASH_SIZE: usize = crate::chip::FLASH_SIZE;
@@ -31,14 +30,13 @@ impl NorFlashError for Error {
 }
 
 pub struct Nvmc<'d> {
-    _p: PhantomData<&'d NVMC>,
+    _p: PeripheralRef<'d, NVMC>,
 }
 
 impl<'d> Nvmc<'d> {
-    pub fn new(_p: impl Unborrow<Target = NVMC> + 'd) -> Self {
-        unborrow!(_p);
-
-        Self { _p: PhantomData }
+    pub fn new(_p: impl Peripheral<P = NVMC> + 'd) -> Self {
+        into_ref!(_p);
+        Self { _p }
     }
 
     fn regs() -> &'static pac::nvmc::RegisterBlock {
diff --git a/embassy-nrf/src/ppi/dppi.rs b/embassy-nrf/src/ppi/dppi.rs
index d0bffb1e0..de856c0ca 100644
--- a/embassy-nrf/src/ppi/dppi.rs
+++ b/embassy-nrf/src/ppi/dppi.rs
@@ -1,9 +1,7 @@
-use core::marker::PhantomData;
-
-use embassy_hal_common::unborrow;
+use embassy_hal_common::into_ref;
 
 use super::{Channel, ConfigurableChannel, Event, Ppi, Task};
-use crate::{pac, Unborrow};
+use crate::{pac, Peripheral};
 
 const DPPI_ENABLE_BIT: u32 = 0x8000_0000;
 const DPPI_CHANNEL_MASK: u32 = 0x0000_00FF;
@@ -13,13 +11,13 @@ fn regs() -> &'static pac::dppic::RegisterBlock {
 }
 
 impl<'d, C: ConfigurableChannel> Ppi<'d, C, 1, 1> {
-    pub fn new_one_to_one(ch: impl Unborrow<Target = C> + 'd, event: Event, task: Task) -> Self {
+    pub fn new_one_to_one(ch: impl Peripheral<P = C> + 'd, event: Event, task: Task) -> Self {
         Ppi::new_many_to_many(ch, [event], [task])
     }
 }
 
 impl<'d, C: ConfigurableChannel> Ppi<'d, C, 1, 2> {
-    pub fn new_one_to_two(ch: impl Unborrow<Target = C> + 'd, event: Event, task1: Task, task2: Task) -> Self {
+    pub fn new_one_to_two(ch: impl Peripheral<P = C> + 'd, event: Event, task1: Task, task2: Task) -> Self {
         Ppi::new_many_to_many(ch, [event], [task1, task2])
     }
 }
@@ -28,11 +26,11 @@ impl<'d, C: ConfigurableChannel, const EVENT_COUNT: usize, const TASK_COUNT: usi
     Ppi<'d, C, EVENT_COUNT, TASK_COUNT>
 {
     pub fn new_many_to_many(
-        ch: impl Unborrow<Target = C> + 'd,
+        ch: impl Peripheral<P = C> + 'd,
         events: [Event; EVENT_COUNT],
         tasks: [Task; TASK_COUNT],
     ) -> Self {
-        unborrow!(ch);
+        into_ref!(ch);
 
         let val = DPPI_ENABLE_BIT | (ch.number() as u32 & DPPI_CHANNEL_MASK);
         for task in tasks {
@@ -48,12 +46,7 @@ impl<'d, C: ConfigurableChannel, const EVENT_COUNT: usize, const TASK_COUNT: usi
             unsafe { event.publish_reg().write_volatile(val) }
         }
 
-        Self {
-            ch,
-            events,
-            tasks,
-            phantom: PhantomData,
-        }
+        Self { ch, events, tasks }
     }
 }
 
diff --git a/embassy-nrf/src/ppi/mod.rs b/embassy-nrf/src/ppi/mod.rs
index 660db6410..23ab011bc 100644
--- a/embassy-nrf/src/ppi/mod.rs
+++ b/embassy-nrf/src/ppi/mod.rs
@@ -15,12 +15,11 @@
 //! many tasks and events, but any single task or event can only be coupled with one channel.
 //!
 
-use core::marker::PhantomData;
 use core::ptr::NonNull;
 
-use embassy_hal_common::unsafe_impl_unborrow;
+use embassy_hal_common::{impl_peripheral, PeripheralRef};
 
-use crate::{peripherals, Unborrow};
+use crate::{peripherals, Peripheral};
 
 #[cfg(feature = "_dppi")]
 mod dppi;
@@ -28,12 +27,11 @@ mod dppi;
 mod ppi;
 
 pub struct Ppi<'d, C: Channel, const EVENT_COUNT: usize, const TASK_COUNT: usize> {
-    ch: C,
+    ch: PeripheralRef<'d, C>,
     #[cfg(feature = "_dppi")]
     events: [Event; EVENT_COUNT],
     #[cfg(feature = "_dppi")]
     tasks: [Task; TASK_COUNT],
-    phantom: PhantomData<&'d mut C>,
 }
 
 const REGISTER_DPPI_CONFIG_OFFSET: usize = 0x80 / core::mem::size_of::<u32>();
@@ -89,16 +87,16 @@ pub(crate) mod sealed {
     pub trait Group {}
 }
 
-pub trait Channel: sealed::Channel + Unborrow<Target = Self> + Sized {
+pub trait Channel: sealed::Channel + Peripheral<P = Self> + Sized {
     /// Returns the number of the channel
     fn number(&self) -> usize;
 }
 
-pub trait ConfigurableChannel: Channel {
+pub trait ConfigurableChannel: Channel + Into<AnyConfigurableChannel> {
     fn degrade(self) -> AnyConfigurableChannel;
 }
 
-pub trait StaticChannel: Channel {
+pub trait StaticChannel: Channel + Into<AnyStaticChannel> {
     fn degrade(self) -> AnyStaticChannel;
 }
 
@@ -119,7 +117,7 @@ pub trait Group: sealed::Group + Sized {
 pub struct AnyStaticChannel {
     pub(crate) number: u8,
 }
-unsafe_impl_unborrow!(AnyStaticChannel);
+impl_peripheral!(AnyStaticChannel);
 impl sealed::Channel for AnyStaticChannel {}
 impl Channel for AnyStaticChannel {
     fn number(&self) -> usize {
@@ -137,7 +135,7 @@ impl StaticChannel for AnyStaticChannel {
 pub struct AnyConfigurableChannel {
     pub(crate) number: u8,
 }
-unsafe_impl_unborrow!(AnyConfigurableChannel);
+impl_peripheral!(AnyConfigurableChannel);
 impl sealed::Channel for AnyConfigurableChannel {}
 impl Channel for AnyConfigurableChannel {
     fn number(&self) -> usize {
@@ -169,6 +167,12 @@ macro_rules! impl_ppi_channel {
                 }
             }
         }
+
+        impl From<peripherals::$type> for crate::ppi::AnyStaticChannel {
+            fn from(val: peripherals::$type) -> Self {
+                crate::ppi::StaticChannel::degrade(val)
+            }
+        }
     };
     ($type:ident, $number:expr => configurable) => {
         impl_ppi_channel!($type, $number);
@@ -180,6 +184,12 @@ macro_rules! impl_ppi_channel {
                 }
             }
         }
+
+        impl From<peripherals::$type> for crate::ppi::AnyConfigurableChannel {
+            fn from(val: peripherals::$type) -> Self {
+                crate::ppi::ConfigurableChannel::degrade(val)
+            }
+        }
     };
 }
 
@@ -189,7 +199,7 @@ macro_rules! impl_ppi_channel {
 pub struct AnyGroup {
     number: u8,
 }
-unsafe_impl_unborrow!(AnyGroup);
+impl_peripheral!(AnyGroup);
 impl sealed::Group for AnyGroup {}
 impl Group for AnyGroup {
     fn number(&self) -> usize {
diff --git a/embassy-nrf/src/ppi/ppi.rs b/embassy-nrf/src/ppi/ppi.rs
index e5c86d444..450a290a2 100644
--- a/embassy-nrf/src/ppi/ppi.rs
+++ b/embassy-nrf/src/ppi/ppi.rs
@@ -1,9 +1,7 @@
-use core::marker::PhantomData;
-
-use embassy_hal_common::unborrow;
+use embassy_hal_common::into_ref;
 
 use super::{Channel, ConfigurableChannel, Event, Ppi, StaticChannel, Task};
-use crate::{pac, Unborrow};
+use crate::{pac, Peripheral};
 
 impl Task {
     fn reg_val(&self) -> u32 {
@@ -22,40 +20,34 @@ fn regs() -> &'static pac::ppi::RegisterBlock {
 
 #[cfg(not(feature = "nrf51"))] // Not for nrf51 because of the fork task
 impl<'d, C: StaticChannel> Ppi<'d, C, 0, 1> {
-    pub fn new_zero_to_one(ch: impl Unborrow<Target = C> + 'd, task: Task) -> Self {
-        unborrow!(ch);
+    pub fn new_zero_to_one(ch: impl Peripheral<P = C> + 'd, task: Task) -> Self {
+        into_ref!(ch);
 
         let r = regs();
         let n = ch.number();
         r.fork[n].tep.write(|w| unsafe { w.bits(task.reg_val()) });
 
-        Self {
-            ch,
-            phantom: PhantomData,
-        }
+        Self { ch }
     }
 }
 
 impl<'d, C: ConfigurableChannel> Ppi<'d, C, 1, 1> {
-    pub fn new_one_to_one(ch: impl Unborrow<Target = C> + 'd, event: Event, task: Task) -> Self {
-        unborrow!(ch);
+    pub fn new_one_to_one(ch: impl Peripheral<P = C> + 'd, event: Event, task: Task) -> Self {
+        into_ref!(ch);
 
         let r = regs();
         let n = ch.number();
         r.ch[n].eep.write(|w| unsafe { w.bits(event.reg_val()) });
         r.ch[n].tep.write(|w| unsafe { w.bits(task.reg_val()) });
 
-        Self {
-            ch,
-            phantom: PhantomData,
-        }
+        Self { ch }
     }
 }
 
 #[cfg(not(feature = "nrf51"))] // Not for nrf51 because of the fork task
 impl<'d, C: ConfigurableChannel> Ppi<'d, C, 1, 2> {
-    pub fn new_one_to_two(ch: impl Unborrow<Target = C> + 'd, event: Event, task1: Task, task2: Task) -> Self {
-        unborrow!(ch);
+    pub fn new_one_to_two(ch: impl Peripheral<P = C> + 'd, event: Event, task1: Task, task2: Task) -> Self {
+        into_ref!(ch);
 
         let r = regs();
         let n = ch.number();
@@ -63,10 +55,7 @@ impl<'d, C: ConfigurableChannel> Ppi<'d, C, 1, 2> {
         r.ch[n].tep.write(|w| unsafe { w.bits(task1.reg_val()) });
         r.fork[n].tep.write(|w| unsafe { w.bits(task2.reg_val()) });
 
-        Self {
-            ch,
-            phantom: PhantomData,
-        }
+        Self { ch }
     }
 }
 
diff --git a/embassy-nrf/src/pwm.rs b/embassy-nrf/src/pwm.rs
index 9a78ff1f1..5f750a91e 100644
--- a/embassy-nrf/src/pwm.rs
+++ b/embassy-nrf/src/pwm.rs
@@ -1,36 +1,35 @@
 #![macro_use]
 
-use core::marker::PhantomData;
 use core::sync::atomic::{compiler_fence, Ordering};
 
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 
 use crate::gpio::sealed::Pin as _;
 use crate::gpio::{AnyPin, Pin as GpioPin, PselBits};
 use crate::interrupt::Interrupt;
 use crate::ppi::{Event, Task};
 use crate::util::slice_in_ram_or;
-use crate::{pac, Unborrow};
+use crate::{pac, Peripheral};
 
 /// SimplePwm is the traditional pwm interface you're probably used to, allowing
 /// to simply set a duty cycle across up to four channels.
 pub struct SimplePwm<'d, T: Instance> {
-    phantom: PhantomData<&'d mut T>,
+    _peri: PeripheralRef<'d, T>,
     duty: [u16; 4],
-    ch0: Option<AnyPin>,
-    ch1: Option<AnyPin>,
-    ch2: Option<AnyPin>,
-    ch3: Option<AnyPin>,
+    ch0: Option<PeripheralRef<'d, AnyPin>>,
+    ch1: Option<PeripheralRef<'d, AnyPin>>,
+    ch2: Option<PeripheralRef<'d, AnyPin>>,
+    ch3: Option<PeripheralRef<'d, AnyPin>>,
 }
 
 /// SequencePwm allows you to offload the updating of a sequence of duty cycles
 /// to up to four channels, as well as repeat that sequence n times.
 pub struct SequencePwm<'d, T: Instance> {
-    phantom: PhantomData<&'d mut T>,
-    ch0: Option<AnyPin>,
-    ch1: Option<AnyPin>,
-    ch2: Option<AnyPin>,
-    ch3: Option<AnyPin>,
+    _peri: PeripheralRef<'d, T>,
+    ch0: Option<PeripheralRef<'d, AnyPin>>,
+    ch1: Option<PeripheralRef<'d, AnyPin>>,
+    ch2: Option<PeripheralRef<'d, AnyPin>>,
+    ch3: Option<PeripheralRef<'d, AnyPin>>,
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -51,41 +50,41 @@ impl<'d, T: Instance> SequencePwm<'d, T> {
     /// Create a new 1-channel PWM
     #[allow(unused_unsafe)]
     pub fn new_1ch(
-        pwm: impl Unborrow<Target = T> + 'd,
-        ch0: impl Unborrow<Target = impl GpioPin> + 'd,
+        pwm: impl Peripheral<P = T> + 'd,
+        ch0: impl Peripheral<P = impl GpioPin> + 'd,
         config: Config,
     ) -> Result<Self, Error> {
-        unborrow!(ch0);
-        Self::new_inner(pwm, Some(ch0.degrade()), None, None, None, config)
+        into_ref!(ch0);
+        Self::new_inner(pwm, Some(ch0.map_into()), None, None, None, config)
     }
 
     /// Create a new 2-channel PWM
     #[allow(unused_unsafe)]
     pub fn new_2ch(
-        pwm: impl Unborrow<Target = T> + 'd,
-        ch0: impl Unborrow<Target = impl GpioPin> + 'd,
-        ch1: impl Unborrow<Target = impl GpioPin> + 'd,
+        pwm: impl Peripheral<P = T> + 'd,
+        ch0: impl Peripheral<P = impl GpioPin> + 'd,
+        ch1: impl Peripheral<P = impl GpioPin> + 'd,
         config: Config,
     ) -> Result<Self, Error> {
-        unborrow!(ch0, ch1);
-        Self::new_inner(pwm, Some(ch0.degrade()), Some(ch1.degrade()), None, None, config)
+        into_ref!(ch0, ch1);
+        Self::new_inner(pwm, Some(ch0.map_into()), Some(ch1.map_into()), None, None, config)
     }
 
     /// Create a new 3-channel PWM
     #[allow(unused_unsafe)]
     pub fn new_3ch(
-        pwm: impl Unborrow<Target = T> + 'd,
-        ch0: impl Unborrow<Target = impl GpioPin> + 'd,
-        ch1: impl Unborrow<Target = impl GpioPin> + 'd,
-        ch2: impl Unborrow<Target = impl GpioPin> + 'd,
+        pwm: impl Peripheral<P = T> + 'd,
+        ch0: impl Peripheral<P = impl GpioPin> + 'd,
+        ch1: impl Peripheral<P = impl GpioPin> + 'd,
+        ch2: impl Peripheral<P = impl GpioPin> + 'd,
         config: Config,
     ) -> Result<Self, Error> {
-        unborrow!(ch0, ch1, ch2);
+        into_ref!(ch0, ch1, ch2);
         Self::new_inner(
             pwm,
-            Some(ch0.degrade()),
-            Some(ch1.degrade()),
-            Some(ch2.degrade()),
+            Some(ch0.map_into()),
+            Some(ch1.map_into()),
+            Some(ch2.map_into()),
             None,
             config,
         )
@@ -94,32 +93,34 @@ impl<'d, T: Instance> SequencePwm<'d, T> {
     /// Create a new 4-channel PWM
     #[allow(unused_unsafe)]
     pub fn new_4ch(
-        pwm: impl Unborrow<Target = T> + 'd,
-        ch0: impl Unborrow<Target = impl GpioPin> + 'd,
-        ch1: impl Unborrow<Target = impl GpioPin> + 'd,
-        ch2: impl Unborrow<Target = impl GpioPin> + 'd,
-        ch3: impl Unborrow<Target = impl GpioPin> + 'd,
+        pwm: impl Peripheral<P = T> + 'd,
+        ch0: impl Peripheral<P = impl GpioPin> + 'd,
+        ch1: impl Peripheral<P = impl GpioPin> + 'd,
+        ch2: impl Peripheral<P = impl GpioPin> + 'd,
+        ch3: impl Peripheral<P = impl GpioPin> + 'd,
         config: Config,
     ) -> Result<Self, Error> {
-        unborrow!(ch0, ch1, ch2, ch3);
+        into_ref!(ch0, ch1, ch2, ch3);
         Self::new_inner(
             pwm,
-            Some(ch0.degrade()),
-            Some(ch1.degrade()),
-            Some(ch2.degrade()),
-            Some(ch3.degrade()),
+            Some(ch0.map_into()),
+            Some(ch1.map_into()),
+            Some(ch2.map_into()),
+            Some(ch3.map_into()),
             config,
         )
     }
 
     fn new_inner(
-        _pwm: impl Unborrow<Target = T> + 'd,
-        ch0: Option<AnyPin>,
-        ch1: Option<AnyPin>,
-        ch2: Option<AnyPin>,
-        ch3: Option<AnyPin>,
+        _pwm: impl Peripheral<P = T> + 'd,
+        ch0: Option<PeripheralRef<'d, AnyPin>>,
+        ch1: Option<PeripheralRef<'d, AnyPin>>,
+        ch2: Option<PeripheralRef<'d, AnyPin>>,
+        ch3: Option<PeripheralRef<'d, AnyPin>>,
         config: Config,
     ) -> Result<Self, Error> {
+        into_ref!(_pwm);
+
         let r = T::regs();
 
         if let Some(pin) = &ch0 {
@@ -168,7 +169,7 @@ impl<'d, T: Instance> SequencePwm<'d, T> {
         r.countertop.write(|w| unsafe { w.countertop().bits(config.max_duty) });
 
         Ok(Self {
-            phantom: PhantomData,
+            _peri: _pwm,
             ch0,
             ch1,
             ch2,
@@ -573,60 +574,74 @@ pub enum CounterMode {
 impl<'d, T: Instance> SimplePwm<'d, T> {
     /// Create a new 1-channel PWM
     #[allow(unused_unsafe)]
-    pub fn new_1ch(pwm: impl Unborrow<Target = T> + 'd, ch0: impl Unborrow<Target = impl GpioPin> + 'd) -> Self {
-        unborrow!(ch0);
-        Self::new_inner(pwm, Some(ch0.degrade()), None, None, None)
+    pub fn new_1ch(pwm: impl Peripheral<P = T> + 'd, ch0: impl Peripheral<P = impl GpioPin> + 'd) -> Self {
+        unsafe {
+            into_ref!(ch0);
+            Self::new_inner(pwm, Some(ch0.map_into()), None, None, None)
+        }
     }
 
     /// Create a new 2-channel PWM
     #[allow(unused_unsafe)]
     pub fn new_2ch(
-        pwm: impl Unborrow<Target = T> + 'd,
-        ch0: impl Unborrow<Target = impl GpioPin> + 'd,
-        ch1: impl Unborrow<Target = impl GpioPin> + 'd,
+        pwm: impl Peripheral<P = T> + 'd,
+        ch0: impl Peripheral<P = impl GpioPin> + 'd,
+        ch1: impl Peripheral<P = impl GpioPin> + 'd,
     ) -> Self {
-        unborrow!(ch0, ch1);
-        Self::new_inner(pwm, Some(ch0.degrade()), Some(ch1.degrade()), None, None)
+        into_ref!(ch0, ch1);
+        Self::new_inner(pwm, Some(ch0.map_into()), Some(ch1.map_into()), None, None)
     }
 
     /// Create a new 3-channel PWM
     #[allow(unused_unsafe)]
     pub fn new_3ch(
-        pwm: impl Unborrow<Target = T> + 'd,
-        ch0: impl Unborrow<Target = impl GpioPin> + 'd,
-        ch1: impl Unborrow<Target = impl GpioPin> + 'd,
-        ch2: impl Unborrow<Target = impl GpioPin> + 'd,
+        pwm: impl Peripheral<P = T> + 'd,
+        ch0: impl Peripheral<P = impl GpioPin> + 'd,
+        ch1: impl Peripheral<P = impl GpioPin> + 'd,
+        ch2: impl Peripheral<P = impl GpioPin> + 'd,
     ) -> Self {
-        unborrow!(ch0, ch1, ch2);
-        Self::new_inner(pwm, Some(ch0.degrade()), Some(ch1.degrade()), Some(ch2.degrade()), None)
+        unsafe {
+            into_ref!(ch0, ch1, ch2);
+            Self::new_inner(
+                pwm,
+                Some(ch0.map_into()),
+                Some(ch1.map_into()),
+                Some(ch2.map_into()),
+                None,
+            )
+        }
     }
 
     /// Create a new 4-channel PWM
     #[allow(unused_unsafe)]
     pub fn new_4ch(
-        pwm: impl Unborrow<Target = T> + 'd,
-        ch0: impl Unborrow<Target = impl GpioPin> + 'd,
-        ch1: impl Unborrow<Target = impl GpioPin> + 'd,
-        ch2: impl Unborrow<Target = impl GpioPin> + 'd,
-        ch3: impl Unborrow<Target = impl GpioPin> + 'd,
+        pwm: impl Peripheral<P = T> + 'd,
+        ch0: impl Peripheral<P = impl GpioPin> + 'd,
+        ch1: impl Peripheral<P = impl GpioPin> + 'd,
+        ch2: impl Peripheral<P = impl GpioPin> + 'd,
+        ch3: impl Peripheral<P = impl GpioPin> + 'd,
     ) -> Self {
-        unborrow!(ch0, ch1, ch2, ch3);
-        Self::new_inner(
-            pwm,
-            Some(ch0.degrade()),
-            Some(ch1.degrade()),
-            Some(ch2.degrade()),
-            Some(ch3.degrade()),
-        )
+        unsafe {
+            into_ref!(ch0, ch1, ch2, ch3);
+            Self::new_inner(
+                pwm,
+                Some(ch0.map_into()),
+                Some(ch1.map_into()),
+                Some(ch2.map_into()),
+                Some(ch3.map_into()),
+            )
+        }
     }
 
     fn new_inner(
-        _pwm: impl Unborrow<Target = T> + 'd,
-        ch0: Option<AnyPin>,
-        ch1: Option<AnyPin>,
-        ch2: Option<AnyPin>,
-        ch3: Option<AnyPin>,
+        _pwm: impl Peripheral<P = T> + 'd,
+        ch0: Option<PeripheralRef<'d, AnyPin>>,
+        ch1: Option<PeripheralRef<'d, AnyPin>>,
+        ch2: Option<PeripheralRef<'d, AnyPin>>,
+        ch3: Option<PeripheralRef<'d, AnyPin>>,
     ) -> Self {
+        into_ref!(_pwm);
+
         let r = T::regs();
 
         if let Some(pin) = &ch0 {
@@ -654,7 +669,7 @@ impl<'d, T: Instance> SimplePwm<'d, T> {
         r.psel.out[3].write(|w| unsafe { w.bits(ch3.psel_bits()) });
 
         let pwm = Self {
-            phantom: PhantomData,
+            _peri: _pwm,
             ch0,
             ch1,
             ch2,
@@ -813,7 +828,7 @@ pub(crate) mod sealed {
     }
 }
 
-pub trait Instance: Unborrow<Target = Self> + sealed::Instance + 'static {
+pub trait Instance: Peripheral<P = Self> + sealed::Instance + 'static {
     type Interrupt: Interrupt;
 }
 
diff --git a/embassy-nrf/src/qdec.rs b/embassy-nrf/src/qdec.rs
index e254328a6..f6daec252 100644
--- a/embassy-nrf/src/qdec.rs
+++ b/embassy-nrf/src/qdec.rs
@@ -1,21 +1,20 @@
 //! Quadrature decoder interface
 
-use core::marker::PhantomData;
 use core::task::Poll;
 
 use embassy::waitqueue::AtomicWaker;
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 use futures::future::poll_fn;
 
 use crate::gpio::sealed::Pin as _;
 use crate::gpio::{AnyPin, Pin as GpioPin};
 use crate::interrupt::InterruptExt;
 use crate::peripherals::QDEC;
-use crate::{interrupt, pac, Unborrow};
+use crate::{interrupt, pac, Peripheral};
 
 /// Quadrature decoder
 pub struct Qdec<'d> {
-    phantom: PhantomData<&'d QDEC>,
+    _p: PeripheralRef<'d, QDEC>,
 }
 
 #[non_exhaustive]
@@ -43,37 +42,37 @@ static WAKER: AtomicWaker = AtomicWaker::new();
 
 impl<'d> Qdec<'d> {
     pub fn new(
-        qdec: impl Unborrow<Target = QDEC> + 'd,
-        irq: impl Unborrow<Target = interrupt::QDEC> + 'd,
-        a: impl Unborrow<Target = impl GpioPin> + 'd,
-        b: impl Unborrow<Target = impl GpioPin> + 'd,
+        qdec: impl Peripheral<P = QDEC> + 'd,
+        irq: impl Peripheral<P = interrupt::QDEC> + 'd,
+        a: impl Peripheral<P = impl GpioPin> + 'd,
+        b: impl Peripheral<P = impl GpioPin> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(a, b);
-        Self::new_inner(qdec, irq, a.degrade(), b.degrade(), None, config)
+        into_ref!(a, b);
+        Self::new_inner(qdec, irq, a.map_into(), b.map_into(), None, config)
     }
 
     pub fn new_with_led(
-        qdec: impl Unborrow<Target = QDEC> + 'd,
-        irq: impl Unborrow<Target = interrupt::QDEC> + 'd,
-        a: impl Unborrow<Target = impl GpioPin> + 'd,
-        b: impl Unborrow<Target = impl GpioPin> + 'd,
-        led: impl Unborrow<Target = impl GpioPin> + 'd,
+        qdec: impl Peripheral<P = QDEC> + 'd,
+        irq: impl Peripheral<P = interrupt::QDEC> + 'd,
+        a: impl Peripheral<P = impl GpioPin> + 'd,
+        b: impl Peripheral<P = impl GpioPin> + 'd,
+        led: impl Peripheral<P = impl GpioPin> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(a, b, led);
-        Self::new_inner(qdec, irq, a.degrade(), b.degrade(), Some(led.degrade()), config)
+        into_ref!(a, b, led);
+        Self::new_inner(qdec, irq, a.map_into(), b.map_into(), Some(led.map_into()), config)
     }
 
     fn new_inner(
-        _t: impl Unborrow<Target = QDEC> + 'd,
-        irq: impl Unborrow<Target = interrupt::QDEC> + 'd,
-        a: AnyPin,
-        b: AnyPin,
-        led: Option<AnyPin>,
+        p: impl Peripheral<P = QDEC> + 'd,
+        irq: impl Peripheral<P = interrupt::QDEC> + 'd,
+        a: PeripheralRef<'d, AnyPin>,
+        b: PeripheralRef<'d, AnyPin>,
+        led: Option<PeripheralRef<'d, AnyPin>>,
         config: Config,
     ) -> Self {
-        unborrow!(irq);
+        into_ref!(p, irq);
         let r = Self::regs();
 
         // Select pins.
@@ -131,7 +130,7 @@ impl<'d> Qdec<'d> {
         });
         irq.enable();
 
-        Self { phantom: PhantomData }
+        Self { _p: p }
     }
 
     /// Perform an asynchronous read of the decoder.
diff --git a/embassy-nrf/src/qspi.rs b/embassy-nrf/src/qspi.rs
index 92fa79b8a..67634b5b7 100644
--- a/embassy-nrf/src/qspi.rs
+++ b/embassy-nrf/src/qspi.rs
@@ -1,20 +1,18 @@
 #![macro_use]
 
-use core::marker::PhantomData;
 use core::ptr;
 use core::task::Poll;
 
 use embassy_hal_common::drop::DropBomb;
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 use futures::future::poll_fn;
 
-use crate::gpio::sealed::Pin as _;
 use crate::gpio::{self, Pin as GpioPin};
 use crate::interrupt::{Interrupt, InterruptExt};
 pub use crate::pac::qspi::ifconfig0::{
     ADDRMODE_A as AddressMode, PPSIZE_A as WritePageSize, READOC_A as ReadOpcode, WRITEOC_A as WriteOpcode,
 };
-use crate::{pac, Unborrow};
+use crate::{pac, Peripheral};
 
 // TODO
 // - config:
@@ -63,38 +61,38 @@ pub enum Error {
 }
 
 pub struct Qspi<'d, T: Instance, const FLASH_SIZE: usize> {
-    irq: T::Interrupt,
+    irq: PeripheralRef<'d, T::Interrupt>,
     dpm_enabled: bool,
-    phantom: PhantomData<&'d mut T>,
 }
 
 impl<'d, T: Instance, const FLASH_SIZE: usize> Qspi<'d, T, FLASH_SIZE> {
     pub fn new(
-        _qspi: impl Unborrow<Target = T> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        sck: impl Unborrow<Target = impl GpioPin> + 'd,
-        csn: impl Unborrow<Target = impl GpioPin> + 'd,
-        io0: impl Unborrow<Target = impl GpioPin> + 'd,
-        io1: impl Unborrow<Target = impl GpioPin> + 'd,
-        io2: impl Unborrow<Target = impl GpioPin> + 'd,
-        io3: impl Unborrow<Target = impl GpioPin> + 'd,
+        _qspi: impl Peripheral<P = T> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        sck: impl Peripheral<P = impl GpioPin> + 'd,
+        csn: impl Peripheral<P = impl GpioPin> + 'd,
+        io0: impl Peripheral<P = impl GpioPin> + 'd,
+        io1: impl Peripheral<P = impl GpioPin> + 'd,
+        io2: impl Peripheral<P = impl GpioPin> + 'd,
+        io3: impl Peripheral<P = impl GpioPin> + 'd,
         config: Config,
     ) -> Qspi<'d, T, FLASH_SIZE> {
-        unborrow!(irq, sck, csn, io0, io1, io2, io3);
+        into_ref!(irq, sck, csn, io0, io1, io2, io3);
 
         let r = T::regs();
 
-        let sck = sck.degrade();
-        let csn = csn.degrade();
-        let io0 = io0.degrade();
-        let io1 = io1.degrade();
-        let io2 = io2.degrade();
-        let io3 = io3.degrade();
-
-        for pin in [&sck, &csn, &io0, &io1, &io2, &io3] {
-            pin.set_high();
-            pin.conf().write(|w| w.dir().output().drive().h0h1());
-        }
+        sck.set_high();
+        csn.set_high();
+        io0.set_high();
+        io1.set_high();
+        io2.set_high();
+        io3.set_high();
+        sck.conf().write(|w| w.dir().output().drive().h0h1());
+        csn.conf().write(|w| w.dir().output().drive().h0h1());
+        io0.conf().write(|w| w.dir().output().drive().h0h1());
+        io1.conf().write(|w| w.dir().output().drive().h0h1());
+        io2.conf().write(|w| w.dir().output().drive().h0h1());
+        io3.conf().write(|w| w.dir().output().drive().h0h1());
 
         r.psel.sck.write(|w| unsafe { w.bits(sck.psel_bits()) });
         r.psel.csn.write(|w| unsafe { w.bits(csn.psel_bits()) });
@@ -143,7 +141,6 @@ impl<'d, T: Instance, const FLASH_SIZE: usize> Qspi<'d, T, FLASH_SIZE> {
         let mut res = Self {
             dpm_enabled: config.deep_power_down.is_some(),
             irq,
-            phantom: PhantomData,
         };
 
         r.events_ready.reset();
@@ -536,7 +533,7 @@ pub(crate) mod sealed {
     }
 }
 
-pub trait Instance: Unborrow<Target = Self> + sealed::Instance + 'static {
+pub trait Instance: Peripheral<P = Self> + sealed::Instance + 'static {
     type Interrupt: Interrupt;
 }
 
diff --git a/embassy-nrf/src/rng.rs b/embassy-nrf/src/rng.rs
index e68ed912e..9bebd6fa3 100644
--- a/embassy-nrf/src/rng.rs
+++ b/embassy-nrf/src/rng.rs
@@ -1,16 +1,15 @@
-use core::marker::PhantomData;
 use core::ptr;
 use core::sync::atomic::{AtomicPtr, Ordering};
 use core::task::Poll;
 
 use embassy::waitqueue::AtomicWaker;
 use embassy_hal_common::drop::OnDrop;
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 use futures::future::poll_fn;
 
 use crate::interrupt::InterruptExt;
 use crate::peripherals::RNG;
-use crate::{interrupt, pac, Unborrow};
+use crate::{interrupt, pac, Peripheral};
 
 impl RNG {
     fn regs() -> &'static pac::rng::RegisterBlock {
@@ -34,8 +33,7 @@ struct State {
 ///
 /// It has a non-blocking API, and a blocking api through `rand`.
 pub struct Rng<'d> {
-    irq: interrupt::RNG,
-    phantom: PhantomData<(&'d mut RNG, &'d mut interrupt::RNG)>,
+    irq: PeripheralRef<'d, interrupt::RNG>,
 }
 
 impl<'d> Rng<'d> {
@@ -45,13 +43,10 @@ impl<'d> Rng<'d> {
     /// e.g. using `mem::forget`.
     ///
     /// The synchronous API is safe.
-    pub fn new(_rng: impl Unborrow<Target = RNG> + 'd, irq: impl Unborrow<Target = interrupt::RNG> + 'd) -> Self {
-        unborrow!(irq);
+    pub fn new(_rng: impl Peripheral<P = RNG> + 'd, irq: impl Peripheral<P = interrupt::RNG> + 'd) -> Self {
+        into_ref!(irq);
 
-        let this = Self {
-            irq,
-            phantom: PhantomData,
-        };
+        let this = Self { irq };
 
         this.stop();
         this.disable_irq();
diff --git a/embassy-nrf/src/saadc.rs b/embassy-nrf/src/saadc.rs
index af1aa8812..6ddc70e52 100644
--- a/embassy-nrf/src/saadc.rs
+++ b/embassy-nrf/src/saadc.rs
@@ -1,11 +1,10 @@
 #![macro_use]
 
-use core::marker::PhantomData;
 use core::sync::atomic::{compiler_fence, Ordering};
 use core::task::Poll;
 
 use embassy::waitqueue::AtomicWaker;
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{impl_peripheral, into_ref, PeripheralRef};
 use futures::future::poll_fn;
 use pac::{saadc, SAADC};
 use saadc::ch::config::{GAIN_A, REFSEL_A, RESP_A, TACQ_A};
@@ -14,10 +13,11 @@ pub(crate) use saadc::ch::pselp::PSELP_A as InputChannel;
 use saadc::oversample::OVERSAMPLE_A;
 use saadc::resolution::VAL_A;
 
+use self::sealed::Input as _;
 use crate::interrupt::InterruptExt;
 use crate::ppi::{ConfigurableChannel, Event, Ppi, Task};
 use crate::timer::{Frequency, Instance as TimerInstance, Timer};
-use crate::{interrupt, pac, peripherals, Unborrow};
+use crate::{interrupt, pac, peripherals, Peripheral};
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
@@ -26,7 +26,7 @@ pub enum Error {}
 
 /// One-shot and continuous SAADC.
 pub struct Saadc<'d, const N: usize> {
-    phantom: PhantomData<&'d mut peripherals::SAADC>,
+    _p: PeripheralRef<'d, peripherals::SAADC>,
 }
 
 static WAKER: AtomicWaker = AtomicWaker::new();
@@ -66,106 +66,37 @@ pub struct ChannelConfig<'d> {
     /// Acquisition time in microseconds.
     pub time: Time,
     /// Positive channel to sample
-    p_channel: InputChannel,
+    p_channel: PeripheralRef<'d, AnyInput>,
     /// An optional negative channel to sample
-    n_channel: Option<InputChannel>,
-
-    phantom: PhantomData<&'d ()>,
-}
-
-/// A dummy `Input` pin implementation for SAADC peripheral sampling from the
-/// internal voltage.
-pub struct VddInput;
-
-unsafe impl Unborrow for VddInput {
-    type Target = VddInput;
-    unsafe fn unborrow(self) -> Self::Target {
-        self
-    }
-}
-
-impl sealed::Input for VddInput {
-    #[cfg(not(feature = "_nrf9160"))]
-    fn channel(&self) -> InputChannel {
-        InputChannel::VDD
-    }
-    #[cfg(feature = "_nrf9160")]
-    fn channel(&self) -> InputChannel {
-        InputChannel::VDDGPIO
-    }
-}
-impl Input for VddInput {}
-
-/// A dummy `Input` pin implementation for SAADC peripheral sampling from the
-/// VDDH / 5 voltage.
-#[cfg(any(feature = "_nrf5340-app", feature = "nrf52833", feature = "nrf52840"))]
-pub struct VddhDiv5Input;
-
-#[cfg(any(feature = "_nrf5340-app", feature = "nrf52833", feature = "nrf52840"))]
-unsafe impl Unborrow for VddhDiv5Input {
-    type Target = VddhDiv5Input;
-    unsafe fn unborrow(self) -> Self::Target {
-        self
-    }
-}
-
-#[cfg(any(feature = "_nrf5340-app", feature = "nrf52833", feature = "nrf52840"))]
-impl sealed::Input for VddhDiv5Input {
-    fn channel(&self) -> InputChannel {
-        InputChannel::VDDHDIV5
-    }
-}
-
-#[cfg(any(feature = "_nrf5340-app", feature = "nrf52833", feature = "nrf52840"))]
-impl Input for VddhDiv5Input {}
-
-pub struct AnyInput {
-    channel: InputChannel,
-}
-
-unsafe impl Unborrow for AnyInput {
-    type Target = AnyInput;
-    unsafe fn unborrow(self) -> Self::Target {
-        self
-    }
-}
-
-impl sealed::Input for AnyInput {
-    fn channel(&self) -> InputChannel {
-        self.channel
-    }
+    n_channel: Option<PeripheralRef<'d, AnyInput>>,
 }
 
-impl Input for AnyInput {}
-
 impl<'d> ChannelConfig<'d> {
     /// Default configuration for single ended channel sampling.
-    pub fn single_ended(input: impl Unborrow<Target = impl Input> + 'd) -> Self {
-        unborrow!(input);
+    pub fn single_ended(input: impl Peripheral<P = impl Input> + 'd) -> Self {
+        into_ref!(input);
         Self {
             reference: Reference::INTERNAL,
             gain: Gain::GAIN1_6,
             resistor: Resistor::BYPASS,
             time: Time::_10US,
-            p_channel: input.channel(),
+            p_channel: input.map_into(),
             n_channel: None,
-            phantom: PhantomData,
         }
     }
     /// Default configuration for differential channel sampling.
     pub fn differential(
-        p_input: impl Unborrow<Target = impl Input> + 'd,
-        n_input: impl Unborrow<Target = impl Input> + 'd,
+        p_input: impl Peripheral<P = impl Input> + 'd,
+        n_input: impl Peripheral<P = impl Input> + 'd,
     ) -> Self {
-        unborrow!(p_input, n_input);
+        into_ref!(p_input, n_input);
         Self {
             reference: Reference::INTERNAL,
             gain: Gain::GAIN1_6,
             resistor: Resistor::BYPASS,
             time: Time::_10US,
-            p_channel: p_input.channel(),
-            n_channel: Some(n_input.channel()),
-            phantom: PhantomData,
+            p_channel: p_input.map_into(),
+            n_channel: Some(n_input.map_into()),
         }
     }
 }
@@ -182,12 +113,12 @@ pub enum SamplerState {
 
 impl<'d, const N: usize> Saadc<'d, N> {
     pub fn new(
-        _saadc: impl Unborrow<Target = peripherals::SAADC> + 'd,
-        irq: impl Unborrow<Target = interrupt::SAADC> + 'd,
+        saadc: impl Peripheral<P = peripherals::SAADC> + 'd,
+        irq: impl Peripheral<P = interrupt::SAADC> + 'd,
         config: Config,
         channel_configs: [ChannelConfig; N],
     ) -> Self {
-        unborrow!(irq);
+        into_ref!(saadc, irq);
 
         let r = unsafe { &*SAADC::ptr() };
 
@@ -199,9 +130,11 @@ impl<'d, const N: usize> Saadc<'d, N> {
         r.oversample.write(|w| w.oversample().variant(oversample.into()));
 
         for (i, cc) in channel_configs.iter().enumerate() {
-            r.ch[i].pselp.write(|w| w.pselp().variant(cc.p_channel));
-            if let Some(n_channel) = cc.n_channel {
-                r.ch[i].pseln.write(|w| unsafe { w.pseln().bits(n_channel as u8) });
+            r.ch[i].pselp.write(|w| w.pselp().variant(cc.p_channel.channel()));
+            if let Some(n_channel) = &cc.n_channel {
+                r.ch[i]
+                    .pseln
+                    .write(|w| unsafe { w.pseln().bits(n_channel.channel() as u8) });
             }
             r.ch[i].config.write(|w| {
                 w.refsel().variant(cc.reference.into());
@@ -230,7 +163,7 @@ impl<'d, const N: usize> Saadc<'d, N> {
         irq.unpend();
         irq.enable();
 
-        Self { phantom: PhantomData }
+        Self { _p: saadc }
     }
 
     fn on_interrupt(_ctx: *mut ()) {
@@ -689,7 +622,7 @@ pub(crate) mod sealed {
 }
 
 /// An input that can be used as either or negative end of a ADC differential in the SAADC periperhal.
-pub trait Input: sealed::Input + Unborrow<Target = Self> + Sized {
+pub trait Input: sealed::Input + Into<AnyInput> + Peripheral<P = Self> + Sized + 'static {
     fn degrade_saadc(self) -> AnyInput {
         AnyInput {
             channel: self.channel(),
@@ -697,13 +630,57 @@ pub trait Input: sealed::Input + Unborrow<Target = Self> + Sized {
     }
 }
 
+pub struct AnyInput {
+    channel: InputChannel,
+}
+
+impl_peripheral!(AnyInput);
+
+impl sealed::Input for AnyInput {
+    fn channel(&self) -> InputChannel {
+        self.channel
+    }
+}
+
+impl Input for AnyInput {}
+
 macro_rules! impl_saadc_input {
     ($pin:ident, $ch:ident) => {
-        impl crate::saadc::sealed::Input for crate::peripherals::$pin {
+        impl_saadc_input!(@local, crate::peripherals::$pin, $ch);
+    };
+    (@local, $pin:ty, $ch:ident) => {
+        impl crate::saadc::sealed::Input for $pin {
             fn channel(&self) -> crate::saadc::InputChannel {
                 crate::saadc::InputChannel::$ch
             }
         }
-        impl crate::saadc::Input for crate::peripherals::$pin {}
+        impl crate::saadc::Input for $pin {}
+
+        impl From<$pin> for crate::saadc::AnyInput {
+            fn from(val: $pin) -> Self {
+                crate::saadc::Input::degrade_saadc(val)
+            }
+        }
     };
 }
+
+/// A dummy `Input` pin implementation for SAADC peripheral sampling from the
+/// internal voltage.
+pub struct VddInput;
+
+impl_peripheral!(VddInput);
+#[cfg(not(feature = "_nrf9160"))]
+impl_saadc_input!(@local, VddInput, VDD);
+#[cfg(feature = "_nrf9160")]
+impl_saadc_input!(@local, VddInput, VDDGPIO);
+
+/// A dummy `Input` pin implementation for SAADC peripheral sampling from the
+/// VDDH / 5 voltage.
+#[cfg(any(feature = "_nrf5340-app", feature = "nrf52833", feature = "nrf52840"))]
+pub struct VddhDiv5Input;
+
+#[cfg(any(feature = "_nrf5340-app", feature = "nrf52833", feature = "nrf52840"))]
+impl_peripheral!(VddhDiv5Input);
+
+#[cfg(any(feature = "_nrf5340-app", feature = "nrf52833", feature = "nrf52840"))]
+impl_saadc_input!(@local, VddhDiv5Input, VDDHDIV5);
diff --git a/embassy-nrf/src/spim.rs b/embassy-nrf/src/spim.rs
index d34d9a0c8..a512b4813 100644
--- a/embassy-nrf/src/spim.rs
+++ b/embassy-nrf/src/spim.rs
@@ -1,11 +1,10 @@
 #![macro_use]
 
-use core::marker::PhantomData;
 use core::sync::atomic::{compiler_fence, Ordering};
 use core::task::Poll;
 
 use embassy_embedded_hal::SetConfig;
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 pub use embedded_hal_02::spi::{Mode, Phase, Polarity, MODE_0, MODE_1, MODE_2, MODE_3};
 use futures::future::poll_fn;
 pub use pac::spim0::frequency::FREQUENCY_A as Frequency;
@@ -15,7 +14,7 @@ use crate::gpio::sealed::Pin as _;
 use crate::gpio::{self, AnyPin, Pin as GpioPin, PselBits};
 use crate::interrupt::{Interrupt, InterruptExt};
 use crate::util::{slice_in_ram_or, slice_ptr_parts, slice_ptr_parts_mut};
-use crate::{pac, Unborrow};
+use crate::{pac, Peripheral};
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
@@ -31,7 +30,7 @@ pub enum Error {
 ///
 /// For more details about EasyDMA, consult the module documentation.
 pub struct Spim<'d, T: Instance> {
-    phantom: PhantomData<&'d mut T>,
+    _p: PeripheralRef<'d, T>,
 }
 
 #[non_exhaustive]
@@ -53,55 +52,55 @@ impl Default for Config {
 
 impl<'d, T: Instance> Spim<'d, T> {
     pub fn new(
-        spim: impl Unborrow<Target = T> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        sck: impl Unborrow<Target = impl GpioPin> + 'd,
-        miso: impl Unborrow<Target = impl GpioPin> + 'd,
-        mosi: impl Unborrow<Target = impl GpioPin> + 'd,
+        spim: impl Peripheral<P = T> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        sck: impl Peripheral<P = impl GpioPin> + 'd,
+        miso: impl Peripheral<P = impl GpioPin> + 'd,
+        mosi: impl Peripheral<P = impl GpioPin> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(sck, miso, mosi);
+        into_ref!(sck, miso, mosi);
         Self::new_inner(
             spim,
             irq,
-            sck.degrade(),
-            Some(miso.degrade()),
-            Some(mosi.degrade()),
+            sck.map_into(),
+            Some(miso.map_into()),
+            Some(mosi.map_into()),
             config,
         )
     }
 
     pub fn new_txonly(
-        spim: impl Unborrow<Target = T> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        sck: impl Unborrow<Target = impl GpioPin> + 'd,
-        mosi: impl Unborrow<Target = impl GpioPin> + 'd,
+        spim: impl Peripheral<P = T> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        sck: impl Peripheral<P = impl GpioPin> + 'd,
+        mosi: impl Peripheral<P = impl GpioPin> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(sck, mosi);
-        Self::new_inner(spim, irq, sck.degrade(), None, Some(mosi.degrade()), config)
+        into_ref!(sck, mosi);
+        Self::new_inner(spim, irq, sck.map_into(), None, Some(mosi.map_into()), config)
     }
 
     pub fn new_rxonly(
-        spim: impl Unborrow<Target = T> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        sck: impl Unborrow<Target = impl GpioPin> + 'd,
-        miso: impl Unborrow<Target = impl GpioPin> + 'd,
+        spim: impl Peripheral<P = T> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        sck: impl Peripheral<P = impl GpioPin> + 'd,
+        miso: impl Peripheral<P = impl GpioPin> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(sck, miso);
-        Self::new_inner(spim, irq, sck.degrade(), Some(miso.degrade()), None, config)
+        into_ref!(sck, miso);
+        Self::new_inner(spim, irq, sck.map_into(), Some(miso.map_into()), None, config)
     }
 
     fn new_inner(
-        _spim: impl Unborrow<Target = T> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        sck: AnyPin,
-        miso: Option<AnyPin>,
-        mosi: Option<AnyPin>,
+        spim: impl Peripheral<P = T> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        sck: PeripheralRef<'d, AnyPin>,
+        miso: Option<PeripheralRef<'d, AnyPin>>,
+        mosi: Option<PeripheralRef<'d, AnyPin>>,
         config: Config,
     ) -> Self {
-        unborrow!(irq);
+        into_ref!(spim, irq);
 
         let r = T::regs();
 
@@ -181,7 +180,7 @@ impl<'d, T: Instance> Spim<'d, T> {
         irq.unpend();
         irq.enable();
 
-        Self { phantom: PhantomData }
+        Self { _p: spim }
     }
 
     fn on_interrupt(_: *mut ()) {
@@ -386,7 +385,7 @@ pub(crate) mod sealed {
     }
 }
 
-pub trait Instance: Unborrow<Target = Self> + sealed::Instance + 'static {
+pub trait Instance: Peripheral<P = Self> + sealed::Instance + 'static {
     type Interrupt: Interrupt;
 }
 
diff --git a/embassy-nrf/src/temp.rs b/embassy-nrf/src/temp.rs
index 43ba3e042..a3b25ce05 100644
--- a/embassy-nrf/src/temp.rs
+++ b/embassy-nrf/src/temp.rs
@@ -1,29 +1,27 @@
 //! Temperature sensor interface.
 
-use core::marker::PhantomData;
 use core::task::Poll;
 
 use embassy::waitqueue::AtomicWaker;
 use embassy_hal_common::drop::OnDrop;
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 use fixed::types::I30F2;
 use futures::future::poll_fn;
 
 use crate::interrupt::InterruptExt;
 use crate::peripherals::TEMP;
-use crate::{interrupt, pac, Unborrow};
+use crate::{interrupt, pac, Peripheral};
 
 /// Integrated temperature sensor.
 pub struct Temp<'d> {
-    _temp: PhantomData<&'d TEMP>,
-    _irq: interrupt::TEMP,
+    _irq: PeripheralRef<'d, interrupt::TEMP>,
 }
 
 static WAKER: AtomicWaker = AtomicWaker::new();
 
 impl<'d> Temp<'d> {
-    pub fn new(_t: impl Unborrow<Target = TEMP> + 'd, irq: impl Unborrow<Target = interrupt::TEMP> + 'd) -> Self {
-        unborrow!(_t, irq);
+    pub fn new(_t: impl Peripheral<P = TEMP> + 'd, irq: impl Peripheral<P = interrupt::TEMP> + 'd) -> Self {
+        into_ref!(_t, irq);
 
         // Enable interrupt that signals temperature values
         irq.disable();
@@ -33,10 +31,7 @@ impl<'d> Temp<'d> {
             WAKER.wake();
         });
         irq.enable();
-        Self {
-            _temp: PhantomData,
-            _irq: irq,
-        }
+        Self { _irq: irq }
     }
 
     /// Perform an asynchronous temperature measurement. The returned future
diff --git a/embassy-nrf/src/timer.rs b/embassy-nrf/src/timer.rs
index c8c36dfae..8deecdc03 100644
--- a/embassy-nrf/src/timer.rs
+++ b/embassy-nrf/src/timer.rs
@@ -5,12 +5,12 @@ use core::task::Poll;
 
 use embassy::waitqueue::AtomicWaker;
 use embassy_hal_common::drop::OnDrop;
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 use futures::future::poll_fn;
 
 use crate::interrupt::{Interrupt, InterruptExt};
 use crate::ppi::{Event, Task};
-use crate::{pac, Unborrow};
+use crate::{pac, Peripheral};
 
 pub(crate) mod sealed {
 
@@ -28,7 +28,7 @@ pub(crate) mod sealed {
     pub trait TimerType {}
 }
 
-pub trait Instance: Unborrow<Target = Self> + sealed::Instance + 'static + Send {
+pub trait Instance: Peripheral<P = Self> + sealed::Instance + 'static + Send {
     type Interrupt: Interrupt;
 }
 pub trait ExtendedInstance: Instance + sealed::ExtendedInstance {}
@@ -95,15 +95,13 @@ impl TimerType for Awaitable {}
 impl TimerType for NotAwaitable {}
 
 pub struct Timer<'d, T: Instance, I: TimerType = NotAwaitable> {
-    phantom: PhantomData<(&'d mut T, I)>,
+    _p: PeripheralRef<'d, T>,
+    _i: PhantomData<I>,
 }
 
 impl<'d, T: Instance> Timer<'d, T, Awaitable> {
-    pub fn new_awaitable(
-        timer: impl Unborrow<Target = T> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-    ) -> Self {
-        unborrow!(irq);
+    pub fn new_awaitable(timer: impl Peripheral<P = T> + 'd, irq: impl Peripheral<P = T::Interrupt> + 'd) -> Self {
+        into_ref!(irq);
 
         irq.set_handler(Self::on_interrupt);
         irq.unpend();
@@ -117,7 +115,7 @@ impl<'d, T: Instance> Timer<'d, T, NotAwaitable> {
     ///
     /// This can be useful for triggering tasks via PPI
     /// `Uarte` uses this internally.
-    pub fn new(timer: impl Unborrow<Target = T> + 'd) -> Self {
+    pub fn new(timer: impl Peripheral<P = T> + 'd) -> Self {
         Self::new_irqless(timer)
     }
 }
@@ -126,10 +124,15 @@ impl<'d, T: Instance, I: TimerType> Timer<'d, T, I> {
     /// Create a `Timer` without an interrupt, meaning `Cc::wait` won't work.
     ///
     /// This is used by the public constructors.
-    fn new_irqless(_timer: impl Unborrow<Target = T> + 'd) -> Self {
+    fn new_irqless(timer: impl Peripheral<P = T> + 'd) -> Self {
+        into_ref!(timer);
+
         let regs = T::regs();
 
-        let mut this = Self { phantom: PhantomData };
+        let mut this = Self {
+            _p: timer,
+            _i: PhantomData,
+        };
 
         // Stop the timer before doing anything else,
         // since changing BITMODE while running can cause 'unpredictable behaviour' according to the specification.
@@ -233,7 +236,8 @@ impl<'d, T: Instance, I: TimerType> Timer<'d, T, I> {
         }
         Cc {
             n,
-            phantom: PhantomData,
+            _p: self._p.reborrow(),
+            _i: PhantomData,
         }
     }
 }
@@ -245,12 +249,13 @@ impl<'d, T: Instance, I: TimerType> Timer<'d, T, I> {
 ///
 /// The timer will fire the register's COMPARE event when its counter reaches the value stored in the register.
 /// When the register's CAPTURE task is triggered, the timer will store the current value of its counter in the register
-pub struct Cc<'a, T: Instance, I: TimerType = NotAwaitable> {
+pub struct Cc<'d, T: Instance, I: TimerType = NotAwaitable> {
     n: usize,
-    phantom: PhantomData<(&'a mut T, I)>,
+    _p: PeripheralRef<'d, T>,
+    _i: PhantomData<I>,
 }
 
-impl<'a, T: Instance> Cc<'a, T, Awaitable> {
+impl<'d, T: Instance> Cc<'d, T, Awaitable> {
     /// Wait until the timer's counter reaches the value stored in this register.
     ///
     /// This requires a mutable reference so that this task's waker cannot be overwritten by a second call to `wait`.
@@ -284,9 +289,9 @@ impl<'a, T: Instance> Cc<'a, T, Awaitable> {
         on_drop.defuse();
     }
 }
-impl<'a, T: Instance> Cc<'a, T, NotAwaitable> {}
+impl<'d, T: Instance> Cc<'d, T, NotAwaitable> {}
 
-impl<'a, T: Instance, I: TimerType> Cc<'a, T, I> {
+impl<'d, T: Instance, I: TimerType> Cc<'d, T, I> {
     /// Get the current value stored in the register.
     pub fn read(&self) -> u32 {
         T::regs().cc[self.n].read().cc().bits()
diff --git a/embassy-nrf/src/twim.rs b/embassy-nrf/src/twim.rs
index 2088691b2..6d6eb84e7 100644
--- a/embassy-nrf/src/twim.rs
+++ b/embassy-nrf/src/twim.rs
@@ -7,7 +7,6 @@
 //! - nRF52832: Section 33
 //! - nRF52840: Section 6.31
 use core::future::Future;
-use core::marker::PhantomData;
 use core::sync::atomic::compiler_fence;
 use core::sync::atomic::Ordering::SeqCst;
 use core::task::Poll;
@@ -16,14 +15,14 @@ use core::task::Poll;
 use embassy::time::{Duration, Instant};
 use embassy::waitqueue::AtomicWaker;
 use embassy_embedded_hal::SetConfig;
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 use futures::future::poll_fn;
 
 use crate::chip::{EASY_DMA_SIZE, FORCE_COPY_BUFFER_SIZE};
 use crate::gpio::Pin as GpioPin;
 use crate::interrupt::{Interrupt, InterruptExt};
 use crate::util::{slice_in_ram, slice_in_ram_or};
-use crate::{gpio, pac, Unborrow};
+use crate::{gpio, pac, Peripheral};
 
 #[derive(Clone, Copy)]
 pub enum Frequency {
@@ -75,18 +74,18 @@ pub enum Error {
 ///
 /// For more details about EasyDMA, consult the module documentation.
 pub struct Twim<'d, T: Instance> {
-    phantom: PhantomData<&'d mut T>,
+    _p: PeripheralRef<'d, T>,
 }
 
 impl<'d, T: Instance> Twim<'d, T> {
     pub fn new(
-        _twim: impl Unborrow<Target = T> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        sda: impl Unborrow<Target = impl GpioPin> + 'd,
-        scl: impl Unborrow<Target = impl GpioPin> + 'd,
+        twim: impl Peripheral<P = T> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        sda: impl Peripheral<P = impl GpioPin> + 'd,
+        scl: impl Peripheral<P = impl GpioPin> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(irq, sda, scl);
+        into_ref!(twim, irq, sda, scl);
 
         let r = T::regs();
 
@@ -136,7 +135,7 @@ impl<'d, T: Instance> Twim<'d, T> {
         irq.unpend();
         irq.enable();
 
-        Self { phantom: PhantomData }
+        Self { _p: twim }
     }
 
     fn on_interrupt(_: *mut ()) {
@@ -707,7 +706,7 @@ pub(crate) mod sealed {
     }
 }
 
-pub trait Instance: Unborrow<Target = Self> + sealed::Instance + 'static {
+pub trait Instance: Peripheral<P = Self> + sealed::Instance + 'static {
     type Interrupt: Interrupt;
 }
 
diff --git a/embassy-nrf/src/uarte.rs b/embassy-nrf/src/uarte.rs
index 459c56c8e..792b8ecca 100644
--- a/embassy-nrf/src/uarte.rs
+++ b/embassy-nrf/src/uarte.rs
@@ -13,12 +13,11 @@
 //! memory may be used given that buffers are passed in directly to its read and write
 //! methods.
 
-use core::marker::PhantomData;
 use core::sync::atomic::{compiler_fence, Ordering};
 use core::task::Poll;
 
 use embassy_hal_common::drop::OnDrop;
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 use futures::future::poll_fn;
 use pac::uarte0::RegisterBlock;
 // Re-export SVD variants to allow user to directly set values.
@@ -31,7 +30,7 @@ use crate::interrupt::{Interrupt, InterruptExt};
 use crate::ppi::{AnyConfigurableChannel, ConfigurableChannel, Event, Ppi, Task};
 use crate::timer::{Frequency, Instance as TimerInstance, Timer};
 use crate::util::slice_in_ram_or;
-use crate::{pac, Unborrow};
+use crate::{pac, Peripheral};
 
 #[derive(Clone)]
 #[non_exhaustive]
@@ -63,7 +62,6 @@ pub enum Error {
 ///
 /// For more details about EasyDMA, consult the module documentation.
 pub struct Uarte<'d, T: Instance> {
-    phantom: PhantomData<&'d mut T>,
     tx: UarteTx<'d, T>,
     rx: UarteRx<'d, T>,
 }
@@ -71,60 +69,60 @@ pub struct Uarte<'d, T: Instance> {
 /// Transmitter interface to the UARTE peripheral obtained
 /// via [Uarte]::split.
 pub struct UarteTx<'d, T: Instance> {
-    phantom: PhantomData<&'d mut T>,
+    _p: PeripheralRef<'d, T>,
 }
 
 /// Receiver interface to the UARTE peripheral obtained
 /// via [Uarte]::split.
 pub struct UarteRx<'d, T: Instance> {
-    phantom: PhantomData<&'d mut T>,
+    _p: PeripheralRef<'d, T>,
 }
 
 impl<'d, T: Instance> Uarte<'d, T> {
     /// Create a new UARTE without hardware flow control
     pub fn new(
-        uarte: impl Unborrow<Target = T> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        rxd: impl Unborrow<Target = impl GpioPin> + 'd,
-        txd: impl Unborrow<Target = impl GpioPin> + 'd,
+        uarte: impl Peripheral<P = T> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        rxd: impl Peripheral<P = impl GpioPin> + 'd,
+        txd: impl Peripheral<P = impl GpioPin> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(rxd, txd);
-        Self::new_inner(uarte, irq, rxd.degrade(), txd.degrade(), None, None, config)
+        into_ref!(rxd, txd);
+        Self::new_inner(uarte, irq, rxd.map_into(), txd.map_into(), None, None, config)
     }
 
     /// Create a new UARTE with hardware flow control (RTS/CTS)
     pub fn new_with_rtscts(
-        uarte: impl Unborrow<Target = T> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        rxd: impl Unborrow<Target = impl GpioPin> + 'd,
-        txd: impl Unborrow<Target = impl GpioPin> + 'd,
-        cts: impl Unborrow<Target = impl GpioPin> + 'd,
-        rts: impl Unborrow<Target = impl GpioPin> + 'd,
+        uarte: impl Peripheral<P = T> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        rxd: impl Peripheral<P = impl GpioPin> + 'd,
+        txd: impl Peripheral<P = impl GpioPin> + 'd,
+        cts: impl Peripheral<P = impl GpioPin> + 'd,
+        rts: impl Peripheral<P = impl GpioPin> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(rxd, txd, cts, rts);
+        into_ref!(rxd, txd, cts, rts);
         Self::new_inner(
             uarte,
             irq,
-            rxd.degrade(),
-            txd.degrade(),
-            Some(cts.degrade()),
-            Some(rts.degrade()),
+            rxd.map_into(),
+            txd.map_into(),
+            Some(cts.map_into()),
+            Some(rts.map_into()),
             config,
         )
     }
 
     fn new_inner(
-        _uarte: impl Unborrow<Target = T> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        rxd: AnyPin,
-        txd: AnyPin,
-        cts: Option<AnyPin>,
-        rts: Option<AnyPin>,
+        uarte: impl Peripheral<P = T> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        rxd: PeripheralRef<'d, AnyPin>,
+        txd: PeripheralRef<'d, AnyPin>,
+        cts: Option<PeripheralRef<'d, AnyPin>>,
+        rts: Option<PeripheralRef<'d, AnyPin>>,
         config: Config,
     ) -> Self {
-        unborrow!(irq);
+        into_ref!(uarte, irq);
 
         let r = T::regs();
 
@@ -161,9 +159,10 @@ impl<'d, T: Instance> Uarte<'d, T> {
         s.tx_rx_refcount.store(2, Ordering::Relaxed);
 
         Self {
-            phantom: PhantomData,
-            tx: UarteTx { phantom: PhantomData },
-            rx: UarteRx { phantom: PhantomData },
+            tx: UarteTx {
+                _p: unsafe { uarte.clone_unchecked() },
+            },
+            rx: UarteRx { _p: uarte },
         }
     }
 
@@ -245,35 +244,35 @@ fn configure(r: &RegisterBlock, config: Config, hardware_flow_control: bool) {
 impl<'d, T: Instance> UarteTx<'d, T> {
     /// Create a new tx-only UARTE without hardware flow control
     pub fn new(
-        uarte: impl Unborrow<Target = T> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        txd: impl Unborrow<Target = impl GpioPin> + 'd,
+        uarte: impl Peripheral<P = T> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        txd: impl Peripheral<P = impl GpioPin> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(txd);
-        Self::new_inner(uarte, irq, txd.degrade(), None, config)
+        into_ref!(txd);
+        Self::new_inner(uarte, irq, txd.map_into(), None, config)
     }
 
     /// Create a new tx-only UARTE with hardware flow control (RTS/CTS)
     pub fn new_with_rtscts(
-        uarte: impl Unborrow<Target = T> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        txd: impl Unborrow<Target = impl GpioPin> + 'd,
-        cts: impl Unborrow<Target = impl GpioPin> + 'd,
+        uarte: impl Peripheral<P = T> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        txd: impl Peripheral<P = impl GpioPin> + 'd,
+        cts: impl Peripheral<P = impl GpioPin> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(txd, cts);
-        Self::new_inner(uarte, irq, txd.degrade(), Some(cts.degrade()), config)
+        into_ref!(txd, cts);
+        Self::new_inner(uarte, irq, txd.map_into(), Some(cts.map_into()), config)
     }
 
     fn new_inner(
-        _uarte: impl Unborrow<Target = T> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        txd: AnyPin,
-        cts: Option<AnyPin>,
+        uarte: impl Peripheral<P = T> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        txd: PeripheralRef<'d, AnyPin>,
+        cts: Option<PeripheralRef<'d, AnyPin>>,
         config: Config,
     ) -> Self {
-        unborrow!(irq);
+        into_ref!(uarte, irq);
 
         let r = T::regs();
 
@@ -299,7 +298,7 @@ impl<'d, T: Instance> UarteTx<'d, T> {
         let s = T::state();
         s.tx_rx_refcount.store(1, Ordering::Relaxed);
 
-        Self { phantom: PhantomData }
+        Self { _p: uarte }
     }
 
     pub async fn write(&mut self, buffer: &[u8]) -> Result<(), Error> {
@@ -437,35 +436,35 @@ impl<'a, T: Instance> Drop for UarteTx<'a, T> {
 impl<'d, T: Instance> UarteRx<'d, T> {
     /// Create a new rx-only UARTE without hardware flow control
     pub fn new(
-        uarte: impl Unborrow<Target = T> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        rxd: impl Unborrow<Target = impl GpioPin> + 'd,
+        uarte: impl Peripheral<P = T> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        rxd: impl Peripheral<P = impl GpioPin> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(rxd);
-        Self::new_inner(uarte, irq, rxd.degrade(), None, config)
+        into_ref!(rxd);
+        Self::new_inner(uarte, irq, rxd.map_into(), None, config)
     }
 
     /// Create a new rx-only UARTE with hardware flow control (RTS/CTS)
     pub fn new_with_rtscts(
-        uarte: impl Unborrow<Target = T> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        rxd: impl Unborrow<Target = impl GpioPin> + 'd,
-        rts: impl Unborrow<Target = impl GpioPin> + 'd,
+        uarte: impl Peripheral<P = T> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        rxd: impl Peripheral<P = impl GpioPin> + 'd,
+        rts: impl Peripheral<P = impl GpioPin> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(rxd, rts);
-        Self::new_inner(uarte, irq, rxd.degrade(), Some(rts.degrade()), config)
+        into_ref!(rxd, rts);
+        Self::new_inner(uarte, irq, rxd.map_into(), Some(rts.map_into()), config)
     }
 
     fn new_inner(
-        _uarte: impl Unborrow<Target = T> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        rxd: AnyPin,
-        rts: Option<AnyPin>,
+        uarte: impl Peripheral<P = T> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        rxd: PeripheralRef<'d, AnyPin>,
+        rts: Option<PeripheralRef<'d, AnyPin>>,
         config: Config,
     ) -> Self {
-        unborrow!(irq);
+        into_ref!(uarte, irq);
 
         let r = T::regs();
 
@@ -491,7 +490,7 @@ impl<'d, T: Instance> UarteRx<'d, T> {
         let s = T::state();
         s.tx_rx_refcount.store(1, Ordering::Relaxed);
 
-        Self { phantom: PhantomData }
+        Self { _p: uarte }
     }
 
     pub async fn read(&mut self, buffer: &mut [u8]) -> Result<(), Error> {
@@ -676,24 +675,24 @@ pub struct UarteWithIdle<'d, U: Instance, T: TimerInstance> {
 impl<'d, U: Instance, T: TimerInstance> UarteWithIdle<'d, U, T> {
     /// Create a new UARTE without hardware flow control
     pub fn new(
-        uarte: impl Unborrow<Target = U> + 'd,
-        timer: impl Unborrow<Target = T> + 'd,
-        ppi_ch1: impl Unborrow<Target = impl ConfigurableChannel + 'd> + 'd,
-        ppi_ch2: impl Unborrow<Target = impl ConfigurableChannel + 'd> + 'd,
-        irq: impl Unborrow<Target = U::Interrupt> + 'd,
-        rxd: impl Unborrow<Target = impl GpioPin> + 'd,
-        txd: impl Unborrow<Target = impl GpioPin> + 'd,
+        uarte: impl Peripheral<P = U> + 'd,
+        timer: impl Peripheral<P = T> + 'd,
+        ppi_ch1: impl Peripheral<P = impl ConfigurableChannel + 'd> + 'd,
+        ppi_ch2: impl Peripheral<P = impl ConfigurableChannel + 'd> + 'd,
+        irq: impl Peripheral<P = U::Interrupt> + 'd,
+        rxd: impl Peripheral<P = impl GpioPin> + 'd,
+        txd: impl Peripheral<P = impl GpioPin> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(rxd, txd);
+        into_ref!(rxd, txd);
         Self::new_inner(
             uarte,
             timer,
             ppi_ch1,
             ppi_ch2,
             irq,
-            rxd.degrade(),
-            txd.degrade(),
+            rxd.map_into(),
+            txd.map_into(),
             None,
             None,
             config,
@@ -702,42 +701,42 @@ impl<'d, U: Instance, T: TimerInstance> UarteWithIdle<'d, U, T> {
 
     /// Create a new UARTE with hardware flow control (RTS/CTS)
     pub fn new_with_rtscts(
-        uarte: impl Unborrow<Target = U> + 'd,
-        timer: impl Unborrow<Target = T> + 'd,
-        ppi_ch1: impl Unborrow<Target = impl ConfigurableChannel + 'd> + 'd,
-        ppi_ch2: impl Unborrow<Target = impl ConfigurableChannel + 'd> + 'd,
-        irq: impl Unborrow<Target = U::Interrupt> + 'd,
-        rxd: impl Unborrow<Target = impl GpioPin> + 'd,
-        txd: impl Unborrow<Target = impl GpioPin> + 'd,
-        cts: impl Unborrow<Target = impl GpioPin> + 'd,
-        rts: impl Unborrow<Target = impl GpioPin> + 'd,
+        uarte: impl Peripheral<P = U> + 'd,
+        timer: impl Peripheral<P = T> + 'd,
+        ppi_ch1: impl Peripheral<P = impl ConfigurableChannel + 'd> + 'd,
+        ppi_ch2: impl Peripheral<P = impl ConfigurableChannel + 'd> + 'd,
+        irq: impl Peripheral<P = U::Interrupt> + 'd,
+        rxd: impl Peripheral<P = impl GpioPin> + 'd,
+        txd: impl Peripheral<P = impl GpioPin> + 'd,
+        cts: impl Peripheral<P = impl GpioPin> + 'd,
+        rts: impl Peripheral<P = impl GpioPin> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(rxd, txd, cts, rts);
+        into_ref!(rxd, txd, cts, rts);
         Self::new_inner(
             uarte,
             timer,
             ppi_ch1,
             ppi_ch2,
             irq,
-            rxd.degrade(),
-            txd.degrade(),
-            Some(cts.degrade()),
-            Some(rts.degrade()),
+            rxd.map_into(),
+            txd.map_into(),
+            Some(cts.map_into()),
+            Some(rts.map_into()),
             config,
         )
     }
 
     fn new_inner(
-        uarte: impl Unborrow<Target = U> + 'd,
-        timer: impl Unborrow<Target = T> + 'd,
-        ppi_ch1: impl Unborrow<Target = impl ConfigurableChannel + 'd> + 'd,
-        ppi_ch2: impl Unborrow<Target = impl ConfigurableChannel + 'd> + 'd,
-        irq: impl Unborrow<Target = U::Interrupt> + 'd,
-        rxd: AnyPin,
-        txd: AnyPin,
-        cts: Option<AnyPin>,
-        rts: Option<AnyPin>,
+        uarte: impl Peripheral<P = U> + 'd,
+        timer: impl Peripheral<P = T> + 'd,
+        ppi_ch1: impl Peripheral<P = impl ConfigurableChannel + 'd> + 'd,
+        ppi_ch2: impl Peripheral<P = impl ConfigurableChannel + 'd> + 'd,
+        irq: impl Peripheral<P = U::Interrupt> + 'd,
+        rxd: PeripheralRef<'d, AnyPin>,
+        txd: PeripheralRef<'d, AnyPin>,
+        cts: Option<PeripheralRef<'d, AnyPin>>,
+        rts: Option<PeripheralRef<'d, AnyPin>>,
         config: Config,
     ) -> Self {
         let baudrate = config.baudrate;
@@ -745,7 +744,7 @@ impl<'d, U: Instance, T: TimerInstance> UarteWithIdle<'d, U, T> {
 
         let mut timer = Timer::new(timer);
 
-        unborrow!(ppi_ch1, ppi_ch2);
+        into_ref!(ppi_ch1, ppi_ch2);
 
         let r = U::regs();
 
@@ -763,7 +762,7 @@ impl<'d, U: Instance, T: TimerInstance> UarteWithIdle<'d, U, T> {
         timer.cc(0).short_compare_stop();
 
         let mut ppi_ch1 = Ppi::new_one_to_two(
-            ppi_ch1.degrade(),
+            ppi_ch1.map_into(),
             Event::from_reg(&r.events_rxdrdy),
             timer.task_clear(),
             timer.task_start(),
@@ -771,7 +770,7 @@ impl<'d, U: Instance, T: TimerInstance> UarteWithIdle<'d, U, T> {
         ppi_ch1.enable();
 
         let mut ppi_ch2 = Ppi::new_one_to_one(
-            ppi_ch2.degrade(),
+            ppi_ch2.map_into(),
             timer.cc(0).event_compare(),
             Task::from_reg(&r.tasks_stoprx),
         );
@@ -958,7 +957,7 @@ pub(crate) mod sealed {
     }
 }
 
-pub trait Instance: Unborrow<Target = Self> + sealed::Instance + 'static + Send {
+pub trait Instance: Peripheral<P = Self> + sealed::Instance + 'static + Send {
     type Interrupt: Interrupt;
 }
 
diff --git a/embassy-nrf/src/usb.rs b/embassy-nrf/src/usb.rs
index a039427f1..378492859 100644
--- a/embassy-nrf/src/usb.rs
+++ b/embassy-nrf/src/usb.rs
@@ -7,7 +7,7 @@ use core::task::Poll;
 
 use cortex_m::peripheral::NVIC;
 use embassy::waitqueue::AtomicWaker;
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 pub use embassy_usb;
 use embassy_usb::driver::{self, EndpointError, Event, Unsupported};
 use embassy_usb::types::{EndpointAddress, EndpointInfo, EndpointType, UsbDirection};
@@ -17,7 +17,7 @@ use pac::usbd::RegisterBlock;
 
 use crate::interrupt::{Interrupt, InterruptExt};
 use crate::util::slice_in_ram;
-use crate::{pac, Unborrow};
+use crate::{pac, Peripheral};
 
 const NEW_AW: AtomicWaker = AtomicWaker::new();
 static BUS_WAKER: AtomicWaker = NEW_AW;
@@ -38,7 +38,7 @@ pub trait UsbSupply {
 }
 
 pub struct Driver<'d, T: Instance, P: UsbSupply> {
-    phantom: PhantomData<&'d mut T>,
+    _p: PeripheralRef<'d, T>,
     alloc_in: Allocator,
     alloc_out: Allocator,
     usb_supply: P,
@@ -166,18 +166,14 @@ impl UsbSupply for SignalledSupply {
 }
 
 impl<'d, T: Instance, P: UsbSupply> Driver<'d, T, P> {
-    pub fn new(
-        _usb: impl Unborrow<Target = T> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        usb_supply: P,
-    ) -> Self {
-        unborrow!(irq);
+    pub fn new(usb: impl Peripheral<P = T> + 'd, irq: impl Peripheral<P = T::Interrupt> + 'd, usb_supply: P) -> Self {
+        into_ref!(usb, irq);
         irq.set_handler(Self::on_interrupt);
         irq.unpend();
         irq.enable();
 
         Self {
-            phantom: PhantomData,
+            _p: usb,
             alloc_in: Allocator::new(),
             alloc_out: Allocator::new(),
             usb_supply,
@@ -273,15 +269,15 @@ impl<'d, T: Instance, P: UsbSupply + 'd> driver::Driver<'d> for Driver<'d, T, P>
         }))
     }
 
-    fn start(self, control_max_packet_size: u16) -> (Self::Bus, Self::ControlPipe) {
+    fn start(mut self, control_max_packet_size: u16) -> (Self::Bus, Self::ControlPipe) {
         (
             Bus {
-                phantom: PhantomData,
+                _p: unsafe { self._p.clone_unchecked() },
                 power_available: false,
                 usb_supply: self.usb_supply,
             },
             ControlPipe {
-                _phantom: PhantomData,
+                _p: self._p,
                 max_packet_size: control_max_packet_size,
             },
         )
@@ -289,7 +285,7 @@ impl<'d, T: Instance, P: UsbSupply + 'd> driver::Driver<'d> for Driver<'d, T, P>
 }
 
 pub struct Bus<'d, T: Instance, P: UsbSupply> {
-    phantom: PhantomData<&'d mut T>,
+    _p: PeripheralRef<'d, T>,
     power_available: bool,
     usb_supply: P,
 }
@@ -750,7 +746,7 @@ impl<'d, T: Instance> driver::EndpointIn for Endpoint<'d, T, In> {
 }
 
 pub struct ControlPipe<'d, T: Instance> {
-    _phantom: PhantomData<&'d mut T>,
+    _p: PeripheralRef<'d, T>,
     max_packet_size: u16,
 }
 
@@ -950,7 +946,7 @@ pub(crate) mod sealed {
     }
 }
 
-pub trait Instance: Unborrow<Target = Self> + sealed::Instance + 'static + Send {
+pub trait Instance: Peripheral<P = Self> + sealed::Instance + 'static + Send {
     type Interrupt: Interrupt;
 }
 
diff --git a/embassy-rp/src/gpio.rs b/embassy-rp/src/gpio.rs
index 53c26de1c..5db1a690b 100644
--- a/embassy-rp/src/gpio.rs
+++ b/embassy-rp/src/gpio.rs
@@ -1,15 +1,15 @@
+#![macro_use]
 use core::future::Future;
-use core::marker::PhantomData;
 use core::pin::Pin as FuturePin;
 use core::task::{Context, Poll};
 
 use embassy::waitqueue::AtomicWaker;
 use embassy_cortex_m::interrupt::{Interrupt, InterruptExt};
-use embassy_hal_common::{unborrow, unsafe_impl_unborrow};
+use embassy_hal_common::{impl_peripheral, into_ref, PeripheralRef};
 
 use crate::pac::common::{Reg, RW};
 use crate::pac::SIO;
-use crate::{interrupt, pac, peripherals, Unborrow};
+use crate::{interrupt, pac, peripherals, Peripheral};
 
 const PIN_COUNT: usize = 30;
 const NEW_AW: AtomicWaker = AtomicWaker::new();
@@ -61,7 +61,7 @@ pub struct Input<'d, T: Pin> {
 
 impl<'d, T: Pin> Input<'d, T> {
     #[inline]
-    pub fn new(pin: impl Unborrow<Target = T> + 'd, pull: Pull) -> Self {
+    pub fn new(pin: impl Peripheral<P = T> + 'd, pull: Pull) -> Self {
         let mut pin = Flex::new(pin);
         pin.set_as_input();
         pin.set_pull(pull);
@@ -177,13 +177,13 @@ unsafe fn IO_IRQ_BANK0() {
 }
 
 struct InputFuture<'a, T: Pin> {
-    pin: &'a mut T,
+    pin: PeripheralRef<'a, T>,
     level: InterruptTrigger,
-    phantom: PhantomData<&'a mut AnyPin>,
 }
 
 impl<'d, T: Pin> InputFuture<'d, T> {
-    pub fn new(pin: &'d mut T, level: InterruptTrigger) -> Self {
+    pub fn new(pin: impl Peripheral<P = T> + 'd, level: InterruptTrigger) -> Self {
+        into_ref!(pin);
         unsafe {
             let irq = interrupt::IO_IRQ_BANK0::steal();
             irq.disable();
@@ -215,11 +215,7 @@ impl<'d, T: Pin> InputFuture<'d, T> {
             irq.enable();
         }
 
-        Self {
-            pin,
-            level,
-            phantom: PhantomData,
-        }
+        Self { pin, level }
     }
 }
 
@@ -294,7 +290,7 @@ pub struct Output<'d, T: Pin> {
 
 impl<'d, T: Pin> Output<'d, T> {
     #[inline]
-    pub fn new(pin: impl Unborrow<Target = T> + 'd, initial_output: Level) -> Self {
+    pub fn new(pin: impl Peripheral<P = T> + 'd, initial_output: Level) -> Self {
         let mut pin = Flex::new(pin);
         match initial_output {
             Level::High => pin.set_high(),
@@ -355,7 +351,7 @@ pub struct OutputOpenDrain<'d, T: Pin> {
 
 impl<'d, T: Pin> OutputOpenDrain<'d, T> {
     #[inline]
-    pub fn new(pin: impl Unborrow<Target = T> + 'd, initial_output: Level) -> Self {
+    pub fn new(pin: impl Peripheral<P = T> + 'd, initial_output: Level) -> Self {
         let mut pin = Flex::new(pin);
         pin.set_low();
         match initial_output {
@@ -419,14 +415,13 @@ impl<'d, T: Pin> OutputOpenDrain<'d, T> {
 /// set while not in output mode, so the pin's level will be 'remembered' when it is not in output
 /// mode.
 pub struct Flex<'d, T: Pin> {
-    pin: T,
-    phantom: PhantomData<&'d mut T>,
+    pin: PeripheralRef<'d, T>,
 }
 
 impl<'d, T: Pin> Flex<'d, T> {
     #[inline]
-    pub fn new(pin: impl Unborrow<Target = T> + 'd) -> Self {
-        unborrow!(pin);
+    pub fn new(pin: impl Peripheral<P = T> + 'd) -> Self {
+        into_ref!(pin);
 
         unsafe {
             pin.pad_ctrl().write(|w| {
@@ -438,10 +433,7 @@ impl<'d, T: Pin> Flex<'d, T> {
             });
         }
 
-        Self {
-            pin,
-            phantom: PhantomData,
-        }
+        Self { pin }
     }
 
     #[inline]
@@ -655,7 +647,7 @@ pub(crate) mod sealed {
     }
 }
 
-pub trait Pin: Unborrow<Target = Self> + sealed::Pin {
+pub trait Pin: Peripheral<P = Self> + Into<AnyPin> + sealed::Pin + Sized + 'static {
     /// Degrade to a generic pin struct
     fn degrade(self) -> AnyPin {
         AnyPin {
@@ -667,7 +659,9 @@ pub trait Pin: Unborrow<Target = Self> + sealed::Pin {
 pub struct AnyPin {
     pin_bank: u8,
 }
-unsafe_impl_unborrow!(AnyPin);
+
+impl_peripheral!(AnyPin);
+
 impl Pin for AnyPin {}
 impl sealed::Pin for AnyPin {
     fn pin_bank(&self) -> u8 {
@@ -685,6 +679,12 @@ macro_rules! impl_pin {
                 ($bank as u8) * 32 + $pin_num
             }
         }
+
+        impl From<peripherals::$name> for crate::gpio::AnyPin {
+            fn from(val: peripherals::$name) -> Self {
+                crate::gpio::Pin::degrade(val)
+            }
+        }
     };
 }
 
diff --git a/embassy-rp/src/lib.rs b/embassy-rp/src/lib.rs
index 7da0d30c1..44150be0d 100644
--- a/embassy-rp/src/lib.rs
+++ b/embassy-rp/src/lib.rs
@@ -17,7 +17,7 @@ mod reset;
 // Reexports
 
 pub use embassy_cortex_m::executor;
-pub use embassy_hal_common::{unborrow, Unborrow};
+pub use embassy_hal_common::{into_ref, Peripheral, PeripheralRef};
 pub use embassy_macros::cortex_m_interrupt as interrupt;
 #[cfg(feature = "unstable-pac")]
 pub use rp2040_pac2 as pac;
diff --git a/embassy-rp/src/spi.rs b/embassy-rp/src/spi.rs
index 6b3f2238a..d0261598e 100644
--- a/embassy-rp/src/spi.rs
+++ b/embassy-rp/src/spi.rs
@@ -1,12 +1,10 @@
-use core::marker::PhantomData;
-
 use embassy_embedded_hal::SetConfig;
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 pub use embedded_hal_02::spi::{Phase, Polarity};
 
 use crate::gpio::sealed::Pin as _;
 use crate::gpio::{AnyPin, Pin as GpioPin};
-use crate::{pac, peripherals, Unborrow};
+use crate::{pac, peripherals, Peripheral};
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
@@ -33,8 +31,7 @@ impl Default for Config {
 }
 
 pub struct Spi<'d, T: Instance> {
-    inner: T,
-    phantom: PhantomData<&'d mut T>,
+    inner: PeripheralRef<'d, T>,
 }
 
 fn div_roundup(a: u32, b: u32) -> u32 {
@@ -62,52 +59,52 @@ fn calc_prescs(freq: u32) -> (u8, u8) {
 
 impl<'d, T: Instance> Spi<'d, T> {
     pub fn new(
-        inner: impl Unborrow<Target = T> + 'd,
-        clk: impl Unborrow<Target = impl ClkPin<T>> + 'd,
-        mosi: impl Unborrow<Target = impl MosiPin<T>> + 'd,
-        miso: impl Unborrow<Target = impl MisoPin<T>> + 'd,
+        inner: impl Peripheral<P = T> + 'd,
+        clk: impl Peripheral<P = impl ClkPin<T> + 'd> + 'd,
+        mosi: impl Peripheral<P = impl MosiPin<T> + 'd> + 'd,
+        miso: impl Peripheral<P = impl MisoPin<T> + 'd> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(clk, mosi, miso);
+        into_ref!(clk, mosi, miso);
         Self::new_inner(
             inner,
-            Some(clk.degrade()),
-            Some(mosi.degrade()),
-            Some(miso.degrade()),
+            Some(clk.map_into()),
+            Some(mosi.map_into()),
+            Some(miso.map_into()),
             None,
             config,
         )
     }
 
     pub fn new_txonly(
-        inner: impl Unborrow<Target = T> + 'd,
-        clk: impl Unborrow<Target = impl ClkPin<T>> + 'd,
-        mosi: impl Unborrow<Target = impl MosiPin<T>> + 'd,
+        inner: impl Peripheral<P = T> + 'd,
+        clk: impl Peripheral<P = impl ClkPin<T> + 'd> + 'd,
+        mosi: impl Peripheral<P = impl MosiPin<T> + 'd> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(clk, mosi);
-        Self::new_inner(inner, Some(clk.degrade()), Some(mosi.degrade()), None, None, config)
+        into_ref!(clk, mosi);
+        Self::new_inner(inner, Some(clk.map_into()), Some(mosi.map_into()), None, None, config)
     }
 
     pub fn new_rxonly(
-        inner: impl Unborrow<Target = T> + 'd,
-        clk: impl Unborrow<Target = impl ClkPin<T>> + 'd,
-        miso: impl Unborrow<Target = impl MisoPin<T>> + 'd,
+        inner: impl Peripheral<P = T> + 'd,
+        clk: impl Peripheral<P = impl ClkPin<T> + 'd> + 'd,
+        miso: impl Peripheral<P = impl MisoPin<T> + 'd> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(clk, miso);
-        Self::new_inner(inner, Some(clk.degrade()), None, Some(miso.degrade()), None, config)
+        into_ref!(clk, miso);
+        Self::new_inner(inner, Some(clk.map_into()), None, Some(miso.map_into()), None, config)
     }
 
     fn new_inner(
-        inner: impl Unborrow<Target = T> + 'd,
-        clk: Option<AnyPin>,
-        mosi: Option<AnyPin>,
-        miso: Option<AnyPin>,
-        cs: Option<AnyPin>,
+        inner: impl Peripheral<P = T> + 'd,
+        clk: Option<PeripheralRef<'d, AnyPin>>,
+        mosi: Option<PeripheralRef<'d, AnyPin>>,
+        miso: Option<PeripheralRef<'d, AnyPin>>,
+        cs: Option<PeripheralRef<'d, AnyPin>>,
         config: Config,
     ) -> Self {
-        unborrow!(inner);
+        into_ref!(inner);
 
         unsafe {
             let p = inner.regs();
@@ -137,10 +134,7 @@ impl<'d, T: Instance> Spi<'d, T> {
                 pin.io().ctrl().write(|w| w.set_funcsel(1));
             }
         }
-        Self {
-            inner,
-            phantom: PhantomData,
-        }
+        Self { inner }
     }
 
     pub fn blocking_write(&mut self, data: &[u8]) -> Result<(), Error> {
diff --git a/embassy-rp/src/uart.rs b/embassy-rp/src/uart.rs
index c95407b6f..b19f043f8 100644
--- a/embassy-rp/src/uart.rs
+++ b/embassy-rp/src/uart.rs
@@ -1,9 +1,7 @@
-use core::marker::PhantomData;
-
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 use gpio::Pin;
 
-use crate::{gpio, pac, peripherals, Unborrow};
+use crate::{gpio, pac, peripherals, Peripheral};
 
 #[non_exhaustive]
 pub struct Config {
@@ -23,20 +21,19 @@ impl Default for Config {
 }
 
 pub struct Uart<'d, T: Instance> {
-    inner: T,
-    phantom: PhantomData<&'d mut T>,
+    inner: PeripheralRef<'d, T>,
 }
 
 impl<'d, T: Instance> Uart<'d, T> {
     pub fn new(
-        inner: impl Unborrow<Target = T> + 'd,
-        tx: impl Unborrow<Target = impl TxPin<T>> + 'd,
-        rx: impl Unborrow<Target = impl RxPin<T>> + 'd,
-        cts: impl Unborrow<Target = impl CtsPin<T>> + 'd,
-        rts: impl Unborrow<Target = impl RtsPin<T>> + 'd,
+        inner: impl Peripheral<P = T> + 'd,
+        tx: impl Peripheral<P = impl TxPin<T>> + 'd,
+        rx: impl Peripheral<P = impl RxPin<T>> + 'd,
+        cts: impl Peripheral<P = impl CtsPin<T>> + 'd,
+        rts: impl Peripheral<P = impl RtsPin<T>> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(inner, tx, rx, cts, rts);
+        into_ref!(inner, tx, rx, cts, rts);
 
         unsafe {
             let p = inner.regs();
@@ -78,10 +75,7 @@ impl<'d, T: Instance> Uart<'d, T> {
             cts.io().ctrl().write(|w| w.set_funcsel(2));
             rts.io().ctrl().write(|w| w.set_funcsel(2));
         }
-        Self {
-            inner,
-            phantom: PhantomData,
-        }
+        Self { inner }
     }
 
     pub fn send(&mut self, data: &[u8]) {
diff --git a/embassy-stm32/src/adc/f1.rs b/embassy-stm32/src/adc/f1.rs
index 74cfac136..50d4f9bf9 100644
--- a/embassy-stm32/src/adc/f1.rs
+++ b/embassy-stm32/src/adc/f1.rs
@@ -1,12 +1,12 @@
 use core::marker::PhantomData;
 
-use embassy_hal_common::unborrow;
+use embassy_hal_common::into_ref;
 use embedded_hal_02::blocking::delay::DelayUs;
 
 use crate::adc::{AdcPin, Instance};
 use crate::rcc::get_freqs;
 use crate::time::Hertz;
-use crate::Unborrow;
+use crate::Peripheral;
 
 pub const VDDA_CALIB_MV: u32 = 3300;
 pub const ADC_MAX: u32 = (1 << 12) - 1;
@@ -91,8 +91,8 @@ pub struct Adc<'d, T: Instance> {
 }
 
 impl<'d, T: Instance> Adc<'d, T> {
-    pub fn new(_peri: impl Unborrow<Target = T> + 'd, delay: &mut impl DelayUs<u32>) -> Self {
-        unborrow!(_peri);
+    pub fn new(_peri: impl Peripheral<P = T> + 'd, delay: &mut impl DelayUs<u32>) -> Self {
+        into_ref!(_peri);
         T::enable();
         T::reset();
         unsafe {
diff --git a/embassy-stm32/src/adc/v2.rs b/embassy-stm32/src/adc/v2.rs
index 936a35562..5c608451b 100644
--- a/embassy-stm32/src/adc/v2.rs
+++ b/embassy-stm32/src/adc/v2.rs
@@ -1,11 +1,11 @@
 use core::marker::PhantomData;
 
-use embassy_hal_common::unborrow;
+use embassy_hal_common::into_ref;
 use embedded_hal_02::blocking::delay::DelayUs;
 
 use crate::adc::{AdcPin, Instance};
 use crate::time::Hertz;
-use crate::Unborrow;
+use crate::Peripheral;
 
 pub const VDDA_CALIB_MV: u32 = 3000;
 
@@ -159,8 +159,8 @@ impl<'d, T> Adc<'d, T>
 where
     T: Instance,
 {
-    pub fn new(_peri: impl Unborrow<Target = T> + 'd, delay: &mut impl DelayUs<u32>) -> Self {
-        unborrow!(_peri);
+    pub fn new(_peri: impl Peripheral<P = T> + 'd, delay: &mut impl DelayUs<u32>) -> Self {
+        into_ref!(_peri);
         enable();
 
         let presc = unsafe { Prescaler::from_pclk2(crate::rcc::get_freqs().apb2) };
diff --git a/embassy-stm32/src/adc/v3.rs b/embassy-stm32/src/adc/v3.rs
index 49d149b18..dbfd18810 100644
--- a/embassy-stm32/src/adc/v3.rs
+++ b/embassy-stm32/src/adc/v3.rs
@@ -1,10 +1,10 @@
 use core::marker::PhantomData;
 
-use embassy_hal_common::unborrow;
+use embassy_hal_common::into_ref;
 use embedded_hal_02::blocking::delay::DelayUs;
 
 use crate::adc::{AdcPin, Instance};
-use crate::Unborrow;
+use crate::Peripheral;
 
 pub const VDDA_CALIB_MV: u32 = 3000;
 
@@ -208,8 +208,8 @@ pub struct Adc<'d, T: Instance> {
 }
 
 impl<'d, T: Instance> Adc<'d, T> {
-    pub fn new(_peri: impl Unborrow<Target = T> + 'd, delay: &mut impl DelayUs<u32>) -> Self {
-        unborrow!(_peri);
+    pub fn new(_peri: impl Peripheral<P = T> + 'd, delay: &mut impl DelayUs<u32>) -> Self {
+        into_ref!(_peri);
         enable();
         unsafe {
             T::regs().cr().modify(|reg| {
diff --git a/embassy-stm32/src/adc/v4.rs b/embassy-stm32/src/adc/v4.rs
index 3f933f4fc..92e8ac369 100644
--- a/embassy-stm32/src/adc/v4.rs
+++ b/embassy-stm32/src/adc/v4.rs
@@ -7,7 +7,7 @@ use pac::adccommon::vals::Presc;
 
 use super::{AdcPin, Instance};
 use crate::time::Hertz;
-use crate::{pac, Unborrow};
+use crate::{pac, Peripheral};
 
 pub enum Resolution {
     SixteenBit,
@@ -322,8 +322,8 @@ pub struct Adc<'d, T: Instance> {
 }
 
 impl<'d, T: Instance + crate::rcc::RccPeripheral> Adc<'d, T> {
-    pub fn new(_peri: impl Unborrow<Target = T> + 'd, delay: &mut impl DelayUs<u16>) -> Self {
-        embassy_hal_common::unborrow!(_peri);
+    pub fn new(_peri: impl Peripheral<P = T> + 'd, delay: &mut impl DelayUs<u16>) -> Self {
+        embassy_hal_common::into_ref!(_peri);
         T::enable();
         T::reset();
 
diff --git a/embassy-stm32/src/can/bxcan.rs b/embassy-stm32/src/can/bxcan.rs
index b54fd3ff3..c0bd44e0f 100644
--- a/embassy-stm32/src/can/bxcan.rs
+++ b/embassy-stm32/src/can/bxcan.rs
@@ -1,25 +1,23 @@
-use core::marker::PhantomData;
 use core::ops::{Deref, DerefMut};
 
 pub use bxcan;
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 
 use crate::gpio::sealed::AFType;
 use crate::rcc::RccPeripheral;
-use crate::{peripherals, Unborrow};
+use crate::{peripherals, Peripheral};
 
-pub struct Can<'d, T: Instance + bxcan::Instance> {
-    phantom: PhantomData<&'d mut T>,
-    can: bxcan::Can<T>,
+pub struct Can<'d, T: Instance> {
+    can: bxcan::Can<BxcanInstance<'d, T>>,
 }
 
-impl<'d, T: Instance + bxcan::Instance> Can<'d, T> {
+impl<'d, T: Instance> Can<'d, T> {
     pub fn new(
-        peri: impl Unborrow<Target = T> + 'd,
-        rx: impl Unborrow<Target = impl RxPin<T>> + 'd,
-        tx: impl Unborrow<Target = impl TxPin<T>> + 'd,
+        peri: impl Peripheral<P = T> + 'd,
+        rx: impl Peripheral<P = impl RxPin<T>> + 'd,
+        tx: impl Peripheral<P = impl TxPin<T>> + 'd,
     ) -> Self {
-        unborrow!(peri, rx, tx);
+        into_ref!(peri, rx, tx);
 
         unsafe {
             rx.set_as_af(rx.af_num(), AFType::Input);
@@ -30,32 +28,29 @@ impl<'d, T: Instance + bxcan::Instance> Can<'d, T> {
         T::reset();
 
         Self {
-            phantom: PhantomData,
-            can: bxcan::Can::builder(peri).enable(),
+            can: bxcan::Can::builder(BxcanInstance(peri)).enable(),
         }
     }
 }
 
-impl<'d, T: Instance + bxcan::Instance> Drop for Can<'d, T> {
+impl<'d, T: Instance> Drop for Can<'d, T> {
     fn drop(&mut self) {
         // Cannot call `free()` because it moves the instance.
         // Manually reset the peripheral.
-        unsafe {
-            T::regs().mcr().write(|w| w.set_reset(true));
-        }
+        unsafe { T::regs().mcr().write(|w| w.set_reset(true)) }
         T::disable();
     }
 }
 
-impl<'d, T: Instance + bxcan::Instance> Deref for Can<'d, T> {
-    type Target = bxcan::Can<T>;
+impl<'d, T: Instance> Deref for Can<'d, T> {
+    type Target = bxcan::Can<BxcanInstance<'d, T>>;
 
     fn deref(&self) -> &Self::Target {
         &self.can
     }
 }
 
-impl<'d, T: Instance + bxcan::Instance> DerefMut for Can<'d, T> {
+impl<'d, T: Instance> DerefMut for Can<'d, T> {
     fn deref_mut(&mut self) -> &mut Self::Target {
         &mut self.can
     }
@@ -63,15 +58,25 @@ impl<'d, T: Instance + bxcan::Instance> DerefMut for Can<'d, T> {
 
 pub(crate) mod sealed {
     pub trait Instance {
+        const REGISTERS: *mut bxcan::RegisterBlock;
+
         fn regs() -> &'static crate::pac::can::Can;
     }
 }
 
 pub trait Instance: sealed::Instance + RccPeripheral {}
 
+pub struct BxcanInstance<'a, T>(PeripheralRef<'a, T>);
+
+unsafe impl<'d, T: Instance> bxcan::Instance for BxcanInstance<'d, T> {
+    const REGISTERS: *mut bxcan::RegisterBlock = T::REGISTERS;
+}
+
 foreach_peripheral!(
     (can, $inst:ident) => {
         impl sealed::Instance for peripherals::$inst {
+            const REGISTERS: *mut bxcan::RegisterBlock = crate::pac::$inst.0 as *mut _;
+
             fn regs() -> &'static crate::pac::can::Can {
                 &crate::pac::$inst
             }
@@ -79,15 +84,12 @@ foreach_peripheral!(
 
         impl Instance for peripherals::$inst {}
 
-        unsafe impl bxcan::Instance for peripherals::$inst {
-            const REGISTERS: *mut bxcan::RegisterBlock = crate::pac::$inst.0 as *mut _;
-        }
     };
 );
 
 foreach_peripheral!(
     (can, CAN) => {
-        unsafe impl bxcan::FilterOwner for peripherals::CAN {
+        unsafe impl<'d> bxcan::FilterOwner for BxcanInstance<'d, peripherals::CAN> {
             const NUM_FILTER_BANKS: u8 = 14;
         }
     };
@@ -102,19 +104,19 @@ foreach_peripheral!(
             ))] {
                 // Most L4 devices and some F7 devices use the name "CAN1"
                 // even if there is no "CAN2" peripheral.
-                unsafe impl bxcan::FilterOwner for peripherals::CAN1 {
+                unsafe impl<'d> bxcan::FilterOwner for BxcanInstance<'d, peripherals::CAN1> {
                     const NUM_FILTER_BANKS: u8 = 14;
                 }
             } else {
-                unsafe impl bxcan::FilterOwner for peripherals::CAN1 {
+                unsafe impl<'d> bxcan::FilterOwner for BxcanInstance<'d, peripherals::CAN1> {
                     const NUM_FILTER_BANKS: u8 = 28;
                 }
-                unsafe impl bxcan::MasterInstance for peripherals::CAN1 {}
+                unsafe impl<'d> bxcan::MasterInstance for BxcanInstance<'d, peripherals::CAN1> {}
             }
         }
     };
     (can, CAN3) => {
-        unsafe impl bxcan::FilterOwner for peripherals::CAN3 {
+        unsafe impl<'d> bxcan::FilterOwner for BxcanInstance<'d, peripherals::CAN3> {
             const NUM_FILTER_BANKS: u8 = 14;
         }
     };
diff --git a/embassy-stm32/src/crc/v1.rs b/embassy-stm32/src/crc/v1.rs
index 87133714c..393089eed 100644
--- a/embassy-stm32/src/crc/v1.rs
+++ b/embassy-stm32/src/crc/v1.rs
@@ -1,31 +1,26 @@
-use core::marker::PhantomData;
-
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 
 use crate::pac::CRC as PAC_CRC;
 use crate::peripherals::CRC;
 use crate::rcc::sealed::RccPeripheral;
-use crate::Unborrow;
+use crate::Peripheral;
 
 pub struct Crc<'d> {
-    _peripheral: CRC,
-    _phantom: PhantomData<&'d mut CRC>,
+    _peri: PeripheralRef<'d, CRC>,
 }
 
 impl<'d> Crc<'d> {
     /// Instantiates the CRC32 peripheral and initializes it to default values.
-    pub fn new(peripheral: impl Unborrow<Target = CRC> + 'd) -> Self {
+    pub fn new(peripheral: impl Peripheral<P = CRC> + 'd) -> Self {
+        into_ref!(peripheral);
+
         // Note: enable and reset come from RccPeripheral.
         // enable CRC clock in RCC.
         CRC::enable();
         // Reset CRC to default values.
         CRC::reset();
-        // Unborrow the peripheral
-        unborrow!(peripheral);
-        let mut instance = Self {
-            _peripheral: peripheral,
-            _phantom: PhantomData,
-        };
+        // Peripheral the peripheral
+        let mut instance = Self { _peri: peripheral };
         instance.reset();
         instance
     }
diff --git a/embassy-stm32/src/crc/v2v3.rs b/embassy-stm32/src/crc/v2v3.rs
index 63f24e4e1..8acb3a770 100644
--- a/embassy-stm32/src/crc/v2v3.rs
+++ b/embassy-stm32/src/crc/v2v3.rs
@@ -1,16 +1,13 @@
-use core::marker::PhantomData;
-
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 
 use crate::pac::crc::vals;
 use crate::pac::CRC as PAC_CRC;
 use crate::peripherals::CRC;
 use crate::rcc::sealed::RccPeripheral;
-use crate::Unborrow;
+use crate::Peripheral;
 
 pub struct Crc<'d> {
-    _peripheral: CRC,
-    _phantom: PhantomData<&'d mut CRC>,
+    _peripheral: PeripheralRef<'d, CRC>,
     _config: Config,
 }
 
@@ -70,16 +67,15 @@ pub enum PolySize {
 
 impl<'d> Crc<'d> {
     /// Instantiates the CRC32 peripheral and initializes it to default values.
-    pub fn new(peripheral: impl Unborrow<Target = CRC> + 'd, config: Config) -> Self {
+    pub fn new(peripheral: impl Peripheral<P = CRC> + 'd, config: Config) -> Self {
         // Note: enable and reset come from RccPeripheral.
         // enable CRC clock in RCC.
         CRC::enable();
         // Reset CRC to default values.
         CRC::reset();
-        unborrow!(peripheral);
+        into_ref!(peripheral);
         let mut instance = Self {
             _peripheral: peripheral,
-            _phantom: PhantomData,
             _config: config,
         };
         CRC::reset();
diff --git a/embassy-stm32/src/dac/v2.rs b/embassy-stm32/src/dac/v2.rs
index ba7856a5a..6b7f41c63 100644
--- a/embassy-stm32/src/dac/v2.rs
+++ b/embassy-stm32/src/dac/v2.rs
@@ -1,10 +1,8 @@
-use core::marker::PhantomData;
-
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 
 use crate::dac::{DacPin, Instance};
 use crate::pac::dac;
-use crate::Unborrow;
+use crate::Peripheral;
 
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
@@ -90,7 +88,7 @@ pub enum Value {
 
 pub struct Dac<'d, T: Instance> {
     channels: u8,
-    phantom: PhantomData<&'d mut T>,
+    _peri: PeripheralRef<'d, T>,
 }
 
 macro_rules! enable {
@@ -102,21 +100,21 @@ macro_rules! enable {
 }
 
 impl<'d, T: Instance> Dac<'d, T> {
-    pub fn new_1ch(peri: impl Unborrow<Target = T> + 'd, _ch1: impl Unborrow<Target = impl DacPin<T, 1>> + 'd) -> Self {
-        unborrow!(peri);
+    pub fn new_1ch(peri: impl Peripheral<P = T> + 'd, _ch1: impl Peripheral<P = impl DacPin<T, 1>> + 'd) -> Self {
+        into_ref!(peri);
         Self::new_inner(peri, 1)
     }
 
     pub fn new_2ch(
-        peri: impl Unborrow<Target = T> + 'd,
-        _ch1: impl Unborrow<Target = impl DacPin<T, 1>> + 'd,
-        _ch2: impl Unborrow<Target = impl DacPin<T, 2>> + 'd,
+        peri: impl Peripheral<P = T> + 'd,
+        _ch1: impl Peripheral<P = impl DacPin<T, 1>> + 'd,
+        _ch2: impl Peripheral<P = impl DacPin<T, 2>> + 'd,
     ) -> Self {
-        unborrow!(peri);
+        into_ref!(peri);
         Self::new_inner(peri, 2)
     }
 
-    fn new_inner(_peri: T, channels: u8) -> Self {
+    fn new_inner(peri: PeripheralRef<'d, T>, channels: u8) -> Self {
         unsafe {
             // Sadly we cannot use `RccPeripheral::enable` since devices are quite inconsistent DAC clock
             // configuration.
@@ -144,10 +142,7 @@ impl<'d, T: Instance> Dac<'d, T> {
             }
         }
 
-        Self {
-            channels,
-            phantom: PhantomData,
-        }
+        Self { channels, _peri: peri }
     }
 
     /// Check the channel is configured
diff --git a/embassy-stm32/src/dcmi.rs b/embassy-stm32/src/dcmi.rs
index f4ca93a71..e28225426 100644
--- a/embassy-stm32/src/dcmi.rs
+++ b/embassy-stm32/src/dcmi.rs
@@ -1,14 +1,13 @@
-use core::marker::PhantomData;
 use core::task::Poll;
 
 use embassy::waitqueue::AtomicWaker;
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 use futures::future::poll_fn;
 
 use crate::gpio::sealed::AFType;
 use crate::gpio::Speed;
 use crate::interrupt::{Interrupt, InterruptExt};
-use crate::Unborrow;
+use crate::Peripheral;
 
 /// The level on the VSync pin when the data is not valid on the parallel interface.
 #[derive(Clone, Copy, PartialEq)]
@@ -70,7 +69,7 @@ impl Default for Config {
 
 macro_rules! config_pins {
     ($($pin:ident),*) => {
-        unborrow!($($pin),*);
+        into_ref!($($pin),*);
         // NOTE(unsafe) Exclusive access to the registers
         critical_section::with(|_| unsafe {
             $(
@@ -82,9 +81,8 @@ macro_rules! config_pins {
 }
 
 pub struct Dcmi<'d, T: Instance, Dma: FrameDma<T>> {
-    inner: T,
-    dma: Dma,
-    phantom: PhantomData<&'d mut T>,
+    inner: PeripheralRef<'d, T>,
+    dma: PeripheralRef<'d, Dma>,
 }
 
 impl<'d, T, Dma> Dcmi<'d, T, Dma>
@@ -93,23 +91,23 @@ where
     Dma: FrameDma<T>,
 {
     pub fn new_8bit(
-        peri: impl Unborrow<Target = T> + 'd,
-        dma: impl Unborrow<Target = Dma> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        d0: impl Unborrow<Target = impl D0Pin<T>> + 'd,
-        d1: impl Unborrow<Target = impl D1Pin<T>> + 'd,
-        d2: impl Unborrow<Target = impl D2Pin<T>> + 'd,
-        d3: impl Unborrow<Target = impl D3Pin<T>> + 'd,
-        d4: impl Unborrow<Target = impl D4Pin<T>> + 'd,
-        d5: impl Unborrow<Target = impl D5Pin<T>> + 'd,
-        d6: impl Unborrow<Target = impl D6Pin<T>> + 'd,
-        d7: impl Unborrow<Target = impl D7Pin<T>> + 'd,
-        v_sync: impl Unborrow<Target = impl VSyncPin<T>> + 'd,
-        h_sync: impl Unborrow<Target = impl HSyncPin<T>> + 'd,
-        pixclk: impl Unborrow<Target = impl PixClkPin<T>> + 'd,
+        peri: impl Peripheral<P = T> + 'd,
+        dma: impl Peripheral<P = Dma> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        d0: impl Peripheral<P = impl D0Pin<T>> + 'd,
+        d1: impl Peripheral<P = impl D1Pin<T>> + 'd,
+        d2: impl Peripheral<P = impl D2Pin<T>> + 'd,
+        d3: impl Peripheral<P = impl D3Pin<T>> + 'd,
+        d4: impl Peripheral<P = impl D4Pin<T>> + 'd,
+        d5: impl Peripheral<P = impl D5Pin<T>> + 'd,
+        d6: impl Peripheral<P = impl D6Pin<T>> + 'd,
+        d7: impl Peripheral<P = impl D7Pin<T>> + 'd,
+        v_sync: impl Peripheral<P = impl VSyncPin<T>> + 'd,
+        h_sync: impl Peripheral<P = impl HSyncPin<T>> + 'd,
+        pixclk: impl Peripheral<P = impl PixClkPin<T>> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(peri, dma, irq);
+        into_ref!(peri, dma, irq);
         config_pins!(d0, d1, d2, d3, d4, d5, d6, d7);
         config_pins!(v_sync, h_sync, pixclk);
 
@@ -117,25 +115,25 @@ where
     }
 
     pub fn new_10bit(
-        peri: impl Unborrow<Target = T> + 'd,
-        dma: impl Unborrow<Target = Dma> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        d0: impl Unborrow<Target = impl D0Pin<T>> + 'd,
-        d1: impl Unborrow<Target = impl D1Pin<T>> + 'd,
-        d2: impl Unborrow<Target = impl D2Pin<T>> + 'd,
-        d3: impl Unborrow<Target = impl D3Pin<T>> + 'd,
-        d4: impl Unborrow<Target = impl D4Pin<T>> + 'd,
-        d5: impl Unborrow<Target = impl D5Pin<T>> + 'd,
-        d6: impl Unborrow<Target = impl D6Pin<T>> + 'd,
-        d7: impl Unborrow<Target = impl D7Pin<T>> + 'd,
-        d8: impl Unborrow<Target = impl D8Pin<T>> + 'd,
-        d9: impl Unborrow<Target = impl D9Pin<T>> + 'd,
-        v_sync: impl Unborrow<Target = impl VSyncPin<T>> + 'd,
-        h_sync: impl Unborrow<Target = impl HSyncPin<T>> + 'd,
-        pixclk: impl Unborrow<Target = impl PixClkPin<T>> + 'd,
+        peri: impl Peripheral<P = T> + 'd,
+        dma: impl Peripheral<P = Dma> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        d0: impl Peripheral<P = impl D0Pin<T>> + 'd,
+        d1: impl Peripheral<P = impl D1Pin<T>> + 'd,
+        d2: impl Peripheral<P = impl D2Pin<T>> + 'd,
+        d3: impl Peripheral<P = impl D3Pin<T>> + 'd,
+        d4: impl Peripheral<P = impl D4Pin<T>> + 'd,
+        d5: impl Peripheral<P = impl D5Pin<T>> + 'd,
+        d6: impl Peripheral<P = impl D6Pin<T>> + 'd,
+        d7: impl Peripheral<P = impl D7Pin<T>> + 'd,
+        d8: impl Peripheral<P = impl D8Pin<T>> + 'd,
+        d9: impl Peripheral<P = impl D9Pin<T>> + 'd,
+        v_sync: impl Peripheral<P = impl VSyncPin<T>> + 'd,
+        h_sync: impl Peripheral<P = impl HSyncPin<T>> + 'd,
+        pixclk: impl Peripheral<P = impl PixClkPin<T>> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(peri, dma, irq);
+        into_ref!(peri, dma, irq);
         config_pins!(d0, d1, d2, d3, d4, d5, d6, d7, d8, d9);
         config_pins!(v_sync, h_sync, pixclk);
 
@@ -143,27 +141,27 @@ where
     }
 
     pub fn new_12bit(
-        peri: impl Unborrow<Target = T> + 'd,
-        dma: impl Unborrow<Target = Dma> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        d0: impl Unborrow<Target = impl D0Pin<T>> + 'd,
-        d1: impl Unborrow<Target = impl D1Pin<T>> + 'd,
-        d2: impl Unborrow<Target = impl D2Pin<T>> + 'd,
-        d3: impl Unborrow<Target = impl D3Pin<T>> + 'd,
-        d4: impl Unborrow<Target = impl D4Pin<T>> + 'd,
-        d5: impl Unborrow<Target = impl D5Pin<T>> + 'd,
-        d6: impl Unborrow<Target = impl D6Pin<T>> + 'd,
-        d7: impl Unborrow<Target = impl D7Pin<T>> + 'd,
-        d8: impl Unborrow<Target = impl D8Pin<T>> + 'd,
-        d9: impl Unborrow<Target = impl D9Pin<T>> + 'd,
-        d10: impl Unborrow<Target = impl D10Pin<T>> + 'd,
-        d11: impl Unborrow<Target = impl D11Pin<T>> + 'd,
-        v_sync: impl Unborrow<Target = impl VSyncPin<T>> + 'd,
-        h_sync: impl Unborrow<Target = impl HSyncPin<T>> + 'd,
-        pixclk: impl Unborrow<Target = impl PixClkPin<T>> + 'd,
+        peri: impl Peripheral<P = T> + 'd,
+        dma: impl Peripheral<P = Dma> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        d0: impl Peripheral<P = impl D0Pin<T>> + 'd,
+        d1: impl Peripheral<P = impl D1Pin<T>> + 'd,
+        d2: impl Peripheral<P = impl D2Pin<T>> + 'd,
+        d3: impl Peripheral<P = impl D3Pin<T>> + 'd,
+        d4: impl Peripheral<P = impl D4Pin<T>> + 'd,
+        d5: impl Peripheral<P = impl D5Pin<T>> + 'd,
+        d6: impl Peripheral<P = impl D6Pin<T>> + 'd,
+        d7: impl Peripheral<P = impl D7Pin<T>> + 'd,
+        d8: impl Peripheral<P = impl D8Pin<T>> + 'd,
+        d9: impl Peripheral<P = impl D9Pin<T>> + 'd,
+        d10: impl Peripheral<P = impl D10Pin<T>> + 'd,
+        d11: impl Peripheral<P = impl D11Pin<T>> + 'd,
+        v_sync: impl Peripheral<P = impl VSyncPin<T>> + 'd,
+        h_sync: impl Peripheral<P = impl HSyncPin<T>> + 'd,
+        pixclk: impl Peripheral<P = impl PixClkPin<T>> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(peri, dma, irq);
+        into_ref!(peri, dma, irq);
         config_pins!(d0, d1, d2, d3, d4, d5, d6, d7, d8, d9, d10, d11);
         config_pins!(v_sync, h_sync, pixclk);
 
@@ -171,29 +169,29 @@ where
     }
 
     pub fn new_14bit(
-        peri: impl Unborrow<Target = T> + 'd,
-        dma: impl Unborrow<Target = Dma> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        d0: impl Unborrow<Target = impl D0Pin<T>> + 'd,
-        d1: impl Unborrow<Target = impl D1Pin<T>> + 'd,
-        d2: impl Unborrow<Target = impl D2Pin<T>> + 'd,
-        d3: impl Unborrow<Target = impl D3Pin<T>> + 'd,
-        d4: impl Unborrow<Target = impl D4Pin<T>> + 'd,
-        d5: impl Unborrow<Target = impl D5Pin<T>> + 'd,
-        d6: impl Unborrow<Target = impl D6Pin<T>> + 'd,
-        d7: impl Unborrow<Target = impl D7Pin<T>> + 'd,
-        d8: impl Unborrow<Target = impl D8Pin<T>> + 'd,
-        d9: impl Unborrow<Target = impl D9Pin<T>> + 'd,
-        d10: impl Unborrow<Target = impl D10Pin<T>> + 'd,
-        d11: impl Unborrow<Target = impl D11Pin<T>> + 'd,
-        d12: impl Unborrow<Target = impl D12Pin<T>> + 'd,
-        d13: impl Unborrow<Target = impl D13Pin<T>> + 'd,
-        v_sync: impl Unborrow<Target = impl VSyncPin<T>> + 'd,
-        h_sync: impl Unborrow<Target = impl HSyncPin<T>> + 'd,
-        pixclk: impl Unborrow<Target = impl PixClkPin<T>> + 'd,
+        peri: impl Peripheral<P = T> + 'd,
+        dma: impl Peripheral<P = Dma> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        d0: impl Peripheral<P = impl D0Pin<T>> + 'd,
+        d1: impl Peripheral<P = impl D1Pin<T>> + 'd,
+        d2: impl Peripheral<P = impl D2Pin<T>> + 'd,
+        d3: impl Peripheral<P = impl D3Pin<T>> + 'd,
+        d4: impl Peripheral<P = impl D4Pin<T>> + 'd,
+        d5: impl Peripheral<P = impl D5Pin<T>> + 'd,
+        d6: impl Peripheral<P = impl D6Pin<T>> + 'd,
+        d7: impl Peripheral<P = impl D7Pin<T>> + 'd,
+        d8: impl Peripheral<P = impl D8Pin<T>> + 'd,
+        d9: impl Peripheral<P = impl D9Pin<T>> + 'd,
+        d10: impl Peripheral<P = impl D10Pin<T>> + 'd,
+        d11: impl Peripheral<P = impl D11Pin<T>> + 'd,
+        d12: impl Peripheral<P = impl D12Pin<T>> + 'd,
+        d13: impl Peripheral<P = impl D13Pin<T>> + 'd,
+        v_sync: impl Peripheral<P = impl VSyncPin<T>> + 'd,
+        h_sync: impl Peripheral<P = impl HSyncPin<T>> + 'd,
+        pixclk: impl Peripheral<P = impl PixClkPin<T>> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(peri, dma, irq);
+        into_ref!(peri, dma, irq);
         config_pins!(d0, d1, d2, d3, d4, d5, d6, d7, d8, d9, d10, d11, d12, d13);
         config_pins!(v_sync, h_sync, pixclk);
 
@@ -201,21 +199,21 @@ where
     }
 
     pub fn new_es_8bit(
-        peri: impl Unborrow<Target = T> + 'd,
-        dma: impl Unborrow<Target = Dma> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        d0: impl Unborrow<Target = impl D0Pin<T>> + 'd,
-        d1: impl Unborrow<Target = impl D1Pin<T>> + 'd,
-        d2: impl Unborrow<Target = impl D2Pin<T>> + 'd,
-        d3: impl Unborrow<Target = impl D3Pin<T>> + 'd,
-        d4: impl Unborrow<Target = impl D4Pin<T>> + 'd,
-        d5: impl Unborrow<Target = impl D5Pin<T>> + 'd,
-        d6: impl Unborrow<Target = impl D6Pin<T>> + 'd,
-        d7: impl Unborrow<Target = impl D7Pin<T>> + 'd,
-        pixclk: impl Unborrow<Target = impl PixClkPin<T>> + 'd,
+        peri: impl Peripheral<P = T> + 'd,
+        dma: impl Peripheral<P = Dma> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        d0: impl Peripheral<P = impl D0Pin<T>> + 'd,
+        d1: impl Peripheral<P = impl D1Pin<T>> + 'd,
+        d2: impl Peripheral<P = impl D2Pin<T>> + 'd,
+        d3: impl Peripheral<P = impl D3Pin<T>> + 'd,
+        d4: impl Peripheral<P = impl D4Pin<T>> + 'd,
+        d5: impl Peripheral<P = impl D5Pin<T>> + 'd,
+        d6: impl Peripheral<P = impl D6Pin<T>> + 'd,
+        d7: impl Peripheral<P = impl D7Pin<T>> + 'd,
+        pixclk: impl Peripheral<P = impl PixClkPin<T>> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(peri, dma, irq);
+        into_ref!(peri, dma, irq);
         config_pins!(d0, d1, d2, d3, d4, d5, d6, d7);
         config_pins!(pixclk);
 
@@ -223,23 +221,23 @@ where
     }
 
     pub fn new_es_10bit(
-        peri: impl Unborrow<Target = T> + 'd,
-        dma: impl Unborrow<Target = Dma> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        d0: impl Unborrow<Target = impl D0Pin<T>> + 'd,
-        d1: impl Unborrow<Target = impl D1Pin<T>> + 'd,
-        d2: impl Unborrow<Target = impl D2Pin<T>> + 'd,
-        d3: impl Unborrow<Target = impl D3Pin<T>> + 'd,
-        d4: impl Unborrow<Target = impl D4Pin<T>> + 'd,
-        d5: impl Unborrow<Target = impl D5Pin<T>> + 'd,
-        d6: impl Unborrow<Target = impl D6Pin<T>> + 'd,
-        d7: impl Unborrow<Target = impl D7Pin<T>> + 'd,
-        d8: impl Unborrow<Target = impl D8Pin<T>> + 'd,
-        d9: impl Unborrow<Target = impl D9Pin<T>> + 'd,
-        pixclk: impl Unborrow<Target = impl PixClkPin<T>> + 'd,
+        peri: impl Peripheral<P = T> + 'd,
+        dma: impl Peripheral<P = Dma> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        d0: impl Peripheral<P = impl D0Pin<T>> + 'd,
+        d1: impl Peripheral<P = impl D1Pin<T>> + 'd,
+        d2: impl Peripheral<P = impl D2Pin<T>> + 'd,
+        d3: impl Peripheral<P = impl D3Pin<T>> + 'd,
+        d4: impl Peripheral<P = impl D4Pin<T>> + 'd,
+        d5: impl Peripheral<P = impl D5Pin<T>> + 'd,
+        d6: impl Peripheral<P = impl D6Pin<T>> + 'd,
+        d7: impl Peripheral<P = impl D7Pin<T>> + 'd,
+        d8: impl Peripheral<P = impl D8Pin<T>> + 'd,
+        d9: impl Peripheral<P = impl D9Pin<T>> + 'd,
+        pixclk: impl Peripheral<P = impl PixClkPin<T>> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(peri, dma, irq);
+        into_ref!(peri, dma, irq);
         config_pins!(d0, d1, d2, d3, d4, d5, d6, d7, d8, d9);
         config_pins!(pixclk);
 
@@ -247,25 +245,25 @@ where
     }
 
     pub fn new_es_12bit(
-        peri: impl Unborrow<Target = T> + 'd,
-        dma: impl Unborrow<Target = Dma> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        d0: impl Unborrow<Target = impl D0Pin<T>> + 'd,
-        d1: impl Unborrow<Target = impl D1Pin<T>> + 'd,
-        d2: impl Unborrow<Target = impl D2Pin<T>> + 'd,
-        d3: impl Unborrow<Target = impl D3Pin<T>> + 'd,
-        d4: impl Unborrow<Target = impl D4Pin<T>> + 'd,
-        d5: impl Unborrow<Target = impl D5Pin<T>> + 'd,
-        d6: impl Unborrow<Target = impl D6Pin<T>> + 'd,
-        d7: impl Unborrow<Target = impl D7Pin<T>> + 'd,
-        d8: impl Unborrow<Target = impl D8Pin<T>> + 'd,
-        d9: impl Unborrow<Target = impl D9Pin<T>> + 'd,
-        d10: impl Unborrow<Target = impl D10Pin<T>> + 'd,
-        d11: impl Unborrow<Target = impl D11Pin<T>> + 'd,
-        pixclk: impl Unborrow<Target = impl PixClkPin<T>> + 'd,
+        peri: impl Peripheral<P = T> + 'd,
+        dma: impl Peripheral<P = Dma> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        d0: impl Peripheral<P = impl D0Pin<T>> + 'd,
+        d1: impl Peripheral<P = impl D1Pin<T>> + 'd,
+        d2: impl Peripheral<P = impl D2Pin<T>> + 'd,
+        d3: impl Peripheral<P = impl D3Pin<T>> + 'd,
+        d4: impl Peripheral<P = impl D4Pin<T>> + 'd,
+        d5: impl Peripheral<P = impl D5Pin<T>> + 'd,
+        d6: impl Peripheral<P = impl D6Pin<T>> + 'd,
+        d7: impl Peripheral<P = impl D7Pin<T>> + 'd,
+        d8: impl Peripheral<P = impl D8Pin<T>> + 'd,
+        d9: impl Peripheral<P = impl D9Pin<T>> + 'd,
+        d10: impl Peripheral<P = impl D10Pin<T>> + 'd,
+        d11: impl Peripheral<P = impl D11Pin<T>> + 'd,
+        pixclk: impl Peripheral<P = impl PixClkPin<T>> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(peri, dma, irq);
+        into_ref!(peri, dma, irq);
         config_pins!(d0, d1, d2, d3, d4, d5, d6, d7, d8, d9, d10, d11);
         config_pins!(pixclk);
 
@@ -273,27 +271,27 @@ where
     }
 
     pub fn new_es_14bit(
-        peri: impl Unborrow<Target = T> + 'd,
-        dma: impl Unborrow<Target = Dma> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        d0: impl Unborrow<Target = impl D0Pin<T>> + 'd,
-        d1: impl Unborrow<Target = impl D1Pin<T>> + 'd,
-        d2: impl Unborrow<Target = impl D2Pin<T>> + 'd,
-        d3: impl Unborrow<Target = impl D3Pin<T>> + 'd,
-        d4: impl Unborrow<Target = impl D4Pin<T>> + 'd,
-        d5: impl Unborrow<Target = impl D5Pin<T>> + 'd,
-        d6: impl Unborrow<Target = impl D6Pin<T>> + 'd,
-        d7: impl Unborrow<Target = impl D7Pin<T>> + 'd,
-        d8: impl Unborrow<Target = impl D8Pin<T>> + 'd,
-        d9: impl Unborrow<Target = impl D9Pin<T>> + 'd,
-        d10: impl Unborrow<Target = impl D10Pin<T>> + 'd,
-        d11: impl Unborrow<Target = impl D11Pin<T>> + 'd,
-        d12: impl Unborrow<Target = impl D12Pin<T>> + 'd,
-        d13: impl Unborrow<Target = impl D13Pin<T>> + 'd,
-        pixclk: impl Unborrow<Target = impl PixClkPin<T>> + 'd,
+        peri: impl Peripheral<P = T> + 'd,
+        dma: impl Peripheral<P = Dma> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        d0: impl Peripheral<P = impl D0Pin<T>> + 'd,
+        d1: impl Peripheral<P = impl D1Pin<T>> + 'd,
+        d2: impl Peripheral<P = impl D2Pin<T>> + 'd,
+        d3: impl Peripheral<P = impl D3Pin<T>> + 'd,
+        d4: impl Peripheral<P = impl D4Pin<T>> + 'd,
+        d5: impl Peripheral<P = impl D5Pin<T>> + 'd,
+        d6: impl Peripheral<P = impl D6Pin<T>> + 'd,
+        d7: impl Peripheral<P = impl D7Pin<T>> + 'd,
+        d8: impl Peripheral<P = impl D8Pin<T>> + 'd,
+        d9: impl Peripheral<P = impl D9Pin<T>> + 'd,
+        d10: impl Peripheral<P = impl D10Pin<T>> + 'd,
+        d11: impl Peripheral<P = impl D11Pin<T>> + 'd,
+        d12: impl Peripheral<P = impl D12Pin<T>> + 'd,
+        d13: impl Peripheral<P = impl D13Pin<T>> + 'd,
+        pixclk: impl Peripheral<P = impl PixClkPin<T>> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(peri, dma, irq);
+        into_ref!(peri, dma, irq);
         config_pins!(d0, d1, d2, d3, d4, d5, d6, d7, d8, d9, d10, d11, d12, d13);
         config_pins!(pixclk);
 
@@ -301,9 +299,9 @@ where
     }
 
     fn new_inner(
-        peri: T,
-        dma: Dma,
-        irq: T::Interrupt,
+        peri: PeripheralRef<'d, T>,
+        dma: PeripheralRef<'d, Dma>,
+        irq: PeripheralRef<'d, T::Interrupt>,
         config: Config,
         use_embedded_synchronization: bool,
         edm: u8,
@@ -327,11 +325,7 @@ where
         irq.unpend();
         irq.enable();
 
-        Self {
-            inner: peri,
-            dma,
-            phantom: PhantomData,
-        }
+        Self { inner: peri, dma }
     }
 
     unsafe fn on_interrupt(_: *mut ()) {
diff --git a/embassy-stm32/src/dma/mod.rs b/embassy-stm32/src/dma/mod.rs
index 87ac38ba8..cc030a93e 100644
--- a/embassy-stm32/src/dma/mod.rs
+++ b/embassy-stm32/src/dma/mod.rs
@@ -8,16 +8,15 @@ mod dmamux;
 mod gpdma;
 
 use core::future::Future;
-use core::marker::PhantomData;
 use core::mem;
 use core::pin::Pin;
 use core::task::{Context, Poll, Waker};
 
-#[cfg(dmamux)]
-pub use dmamux::*;
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{impl_peripheral, into_ref};
 
-use crate::Unborrow;
+#[cfg(dmamux)]
+pub use self::dmamux::*;
+use crate::Peripheral;
 
 #[cfg(feature = "unstable-pac")]
 pub mod low_level {
@@ -207,17 +206,19 @@ impl Default for TransferOptions {
 }
 
 mod transfers {
+    use embassy_hal_common::PeripheralRef;
+
     use super::*;
 
     #[allow(unused)]
     pub fn read<'a, W: Word>(
-        channel: impl Unborrow<Target = impl Channel> + 'a,
+        channel: impl Peripheral<P = impl Channel> + 'a,
         request: Request,
         reg_addr: *mut W,
         buf: &'a mut [W],
     ) -> impl Future<Output = ()> + 'a {
         assert!(buf.len() > 0 && buf.len() <= 0xFFFF);
-        unborrow!(channel);
+        into_ref!(channel);
 
         unsafe { channel.start_read::<W>(request, reg_addr, buf, Default::default()) };
 
@@ -226,13 +227,13 @@ mod transfers {
 
     #[allow(unused)]
     pub fn write<'a, W: Word>(
-        channel: impl Unborrow<Target = impl Channel> + 'a,
+        channel: impl Peripheral<P = impl Channel> + 'a,
         request: Request,
         buf: &'a [W],
         reg_addr: *mut W,
     ) -> impl Future<Output = ()> + 'a {
         assert!(buf.len() > 0 && buf.len() <= 0xFFFF);
-        unborrow!(channel);
+        into_ref!(channel);
 
         unsafe { channel.start_write::<W>(request, buf, reg_addr, Default::default()) };
 
@@ -241,13 +242,13 @@ mod transfers {
 
     #[allow(unused)]
     pub fn write_repeated<'a, W: Word>(
-        channel: impl Unborrow<Target = impl Channel> + 'a,
+        channel: impl Peripheral<P = impl Channel> + 'a,
         request: Request,
         repeated: W,
         count: usize,
         reg_addr: *mut W,
     ) -> impl Future<Output = ()> + 'a {
-        unborrow!(channel);
+        into_ref!(channel);
 
         unsafe { channel.start_write_repeated::<W>(request, repeated, count, reg_addr, Default::default()) };
 
@@ -255,17 +256,13 @@ mod transfers {
     }
 
     pub(crate) struct Transfer<'a, C: Channel> {
-        channel: C,
-        _phantom: PhantomData<&'a mut C>,
+        channel: PeripheralRef<'a, C>,
     }
 
     impl<'a, C: Channel> Transfer<'a, C> {
-        pub(crate) fn new(channel: impl Unborrow<Target = C> + 'a) -> Self {
-            unborrow!(channel);
-            Self {
-                channel,
-                _phantom: PhantomData,
-            }
+        pub(crate) fn new(channel: impl Peripheral<P = C> + 'a) -> Self {
+            into_ref!(channel);
+            Self { channel }
         }
     }
 
@@ -290,17 +287,11 @@ mod transfers {
     }
 }
 
-pub trait Channel: sealed::Channel + Unborrow<Target = Self> + 'static {}
+pub trait Channel: sealed::Channel + Peripheral<P = Self> + 'static {}
 
 pub struct NoDma;
 
-unsafe impl Unborrow for NoDma {
-    type Target = NoDma;
-
-    unsafe fn unborrow(self) -> Self::Target {
-        self
-    }
-}
+impl_peripheral!(NoDma);
 
 // safety: must be called only once at startup
 pub(crate) unsafe fn init() {
diff --git a/embassy-stm32/src/eth/v1/mod.rs b/embassy-stm32/src/eth/v1/mod.rs
index 7985acc5a..5e31c32b5 100644
--- a/embassy-stm32/src/eth/v1/mod.rs
+++ b/embassy-stm32/src/eth/v1/mod.rs
@@ -6,7 +6,7 @@ use core::task::Waker;
 
 use embassy::waitqueue::AtomicWaker;
 use embassy_cortex_m::peripheral::{PeripheralMutex, PeripheralState, StateStorage};
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 use embassy_net::{Device, DeviceCapabilities, LinkState, PacketBuf, MTU};
 
 use crate::gpio::sealed::{AFType, Pin as __GpioPin};
@@ -16,7 +16,7 @@ use crate::pac::AFIO;
 #[cfg(any(eth_v1b, eth_v1c))]
 use crate::pac::SYSCFG;
 use crate::pac::{ETH, RCC};
-use crate::Unborrow;
+use crate::Peripheral;
 
 mod descriptors;
 mod rx_desc;
@@ -36,7 +36,7 @@ impl<'d, T: Instance, const TX: usize, const RX: usize> State<'d, T, TX, RX> {
 
 pub struct Ethernet<'d, T: Instance, P: PHY, const TX: usize, const RX: usize> {
     state: PeripheralMutex<'d, Inner<'d, T, TX, RX>>,
-    pins: [AnyPin; 9],
+    pins: [PeripheralRef<'d, AnyPin>; 9],
     _phy: P,
     clock_range: Cr,
     phy_addr: u8,
@@ -86,22 +86,22 @@ impl<'d, T: Instance, P: PHY, const TX: usize, const RX: usize> Ethernet<'d, T,
     /// safety: the returned instance is not leak-safe
     pub unsafe fn new(
         state: &'d mut State<'d, T, TX, RX>,
-        peri: impl Unborrow<Target = T> + 'd,
-        interrupt: impl Unborrow<Target = crate::interrupt::ETH> + 'd,
-        ref_clk: impl Unborrow<Target = impl RefClkPin<T>> + 'd,
-        mdio: impl Unborrow<Target = impl MDIOPin<T>> + 'd,
-        mdc: impl Unborrow<Target = impl MDCPin<T>> + 'd,
-        crs: impl Unborrow<Target = impl CRSPin<T>> + 'd,
-        rx_d0: impl Unborrow<Target = impl RXD0Pin<T>> + 'd,
-        rx_d1: impl Unborrow<Target = impl RXD1Pin<T>> + 'd,
-        tx_d0: impl Unborrow<Target = impl TXD0Pin<T>> + 'd,
-        tx_d1: impl Unborrow<Target = impl TXD1Pin<T>> + 'd,
-        tx_en: impl Unborrow<Target = impl TXEnPin<T>> + 'd,
+        peri: impl Peripheral<P = T> + 'd,
+        interrupt: impl Peripheral<P = crate::interrupt::ETH> + 'd,
+        ref_clk: impl Peripheral<P = impl RefClkPin<T>> + 'd,
+        mdio: impl Peripheral<P = impl MDIOPin<T>> + 'd,
+        mdc: impl Peripheral<P = impl MDCPin<T>> + 'd,
+        crs: impl Peripheral<P = impl CRSPin<T>> + 'd,
+        rx_d0: impl Peripheral<P = impl RXD0Pin<T>> + 'd,
+        rx_d1: impl Peripheral<P = impl RXD1Pin<T>> + 'd,
+        tx_d0: impl Peripheral<P = impl TXD0Pin<T>> + 'd,
+        tx_d1: impl Peripheral<P = impl TXD1Pin<T>> + 'd,
+        tx_en: impl Peripheral<P = impl TXEnPin<T>> + 'd,
         phy: P,
         mac_addr: [u8; 6],
         phy_addr: u8,
     ) -> Self {
-        unborrow!(interrupt, ref_clk, mdio, mdc, crs, rx_d0, rx_d1, tx_d0, tx_d1, tx_en);
+        into_ref!(interrupt, ref_clk, mdio, mdc, crs, rx_d0, rx_d1, tx_d0, tx_d1, tx_en);
 
         // Enable the necessary Clocks
         // NOTE(unsafe) We have exclusive access to the registers
@@ -207,15 +207,15 @@ impl<'d, T: Instance, P: PHY, const TX: usize, const RX: usize> Ethernet<'d, T,
         };
 
         let pins = [
-            ref_clk.degrade(),
-            mdio.degrade(),
-            mdc.degrade(),
-            crs.degrade(),
-            rx_d0.degrade(),
-            rx_d1.degrade(),
-            tx_d0.degrade(),
-            tx_d1.degrade(),
-            tx_en.degrade(),
+            ref_clk.map_into(),
+            mdio.map_into(),
+            mdc.map_into(),
+            crs.map_into(),
+            rx_d0.map_into(),
+            rx_d1.map_into(),
+            tx_d0.map_into(),
+            tx_d1.map_into(),
+            tx_en.map_into(),
         ];
 
         let mut this = Self {
@@ -370,7 +370,7 @@ struct Inner<'d, T: Instance, const TX: usize, const RX: usize> {
 }
 
 impl<'d, T: Instance, const TX: usize, const RX: usize> Inner<'d, T, TX, RX> {
-    pub fn new(_peri: impl Unborrow<Target = T> + 'd) -> Self {
+    pub fn new(_peri: impl Peripheral<P = T> + 'd) -> Self {
         Self {
             _peri: PhantomData,
             desc_ring: DescriptorRing::new(),
diff --git a/embassy-stm32/src/eth/v2/mod.rs b/embassy-stm32/src/eth/v2/mod.rs
index 2b1caf992..2b4a9367b 100644
--- a/embassy-stm32/src/eth/v2/mod.rs
+++ b/embassy-stm32/src/eth/v2/mod.rs
@@ -4,13 +4,13 @@ use core::task::Waker;
 
 use embassy::waitqueue::AtomicWaker;
 use embassy_cortex_m::peripheral::{PeripheralMutex, PeripheralState, StateStorage};
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 use embassy_net::{Device, DeviceCapabilities, LinkState, PacketBuf, MTU};
 
 use crate::gpio::sealed::{AFType, Pin as _};
 use crate::gpio::{AnyPin, Speed};
 use crate::pac::{ETH, RCC, SYSCFG};
-use crate::Unborrow;
+use crate::Peripheral;
 
 mod descriptors;
 use descriptors::DescriptorRing;
@@ -25,7 +25,7 @@ impl<'d, T: Instance, const TX: usize, const RX: usize> State<'d, T, TX, RX> {
 }
 pub struct Ethernet<'d, T: Instance, P: PHY, const TX: usize, const RX: usize> {
     state: PeripheralMutex<'d, Inner<'d, T, TX, RX>>,
-    pins: [AnyPin; 9],
+    pins: [PeripheralRef<'d, AnyPin>; 9],
     _phy: P,
     clock_range: u8,
     phy_addr: u8,
@@ -48,22 +48,22 @@ impl<'d, T: Instance, P: PHY, const TX: usize, const RX: usize> Ethernet<'d, T,
     /// safety: the returned instance is not leak-safe
     pub unsafe fn new(
         state: &'d mut State<'d, T, TX, RX>,
-        peri: impl Unborrow<Target = T> + 'd,
-        interrupt: impl Unborrow<Target = crate::interrupt::ETH> + 'd,
-        ref_clk: impl Unborrow<Target = impl RefClkPin<T>> + 'd,
-        mdio: impl Unborrow<Target = impl MDIOPin<T>> + 'd,
-        mdc: impl Unborrow<Target = impl MDCPin<T>> + 'd,
-        crs: impl Unborrow<Target = impl CRSPin<T>> + 'd,
-        rx_d0: impl Unborrow<Target = impl RXD0Pin<T>> + 'd,
-        rx_d1: impl Unborrow<Target = impl RXD1Pin<T>> + 'd,
-        tx_d0: impl Unborrow<Target = impl TXD0Pin<T>> + 'd,
-        tx_d1: impl Unborrow<Target = impl TXD1Pin<T>> + 'd,
-        tx_en: impl Unborrow<Target = impl TXEnPin<T>> + 'd,
+        peri: impl Peripheral<P = T> + 'd,
+        interrupt: impl Peripheral<P = crate::interrupt::ETH> + 'd,
+        ref_clk: impl Peripheral<P = impl RefClkPin<T>> + 'd,
+        mdio: impl Peripheral<P = impl MDIOPin<T>> + 'd,
+        mdc: impl Peripheral<P = impl MDCPin<T>> + 'd,
+        crs: impl Peripheral<P = impl CRSPin<T>> + 'd,
+        rx_d0: impl Peripheral<P = impl RXD0Pin<T>> + 'd,
+        rx_d1: impl Peripheral<P = impl RXD1Pin<T>> + 'd,
+        tx_d0: impl Peripheral<P = impl TXD0Pin<T>> + 'd,
+        tx_d1: impl Peripheral<P = impl TXD1Pin<T>> + 'd,
+        tx_en: impl Peripheral<P = impl TXEnPin<T>> + 'd,
         phy: P,
         mac_addr: [u8; 6],
         phy_addr: u8,
     ) -> Self {
-        unborrow!(interrupt, ref_clk, mdio, mdc, crs, rx_d0, rx_d1, tx_d0, tx_d1, tx_en);
+        into_ref!(interrupt, ref_clk, mdio, mdc, crs, rx_d0, rx_d1, tx_d0, tx_d1, tx_en);
 
         // Enable the necessary Clocks
         // NOTE(unsafe) We have exclusive access to the registers
@@ -143,15 +143,15 @@ impl<'d, T: Instance, P: PHY, const TX: usize, const RX: usize> Ethernet<'d, T,
         };
 
         let pins = [
-            ref_clk.degrade(),
-            mdio.degrade(),
-            mdc.degrade(),
-            crs.degrade(),
-            rx_d0.degrade(),
-            rx_d1.degrade(),
-            tx_d0.degrade(),
-            tx_d1.degrade(),
-            tx_en.degrade(),
+            ref_clk.map_into(),
+            mdio.map_into(),
+            mdc.map_into(),
+            crs.map_into(),
+            rx_d0.map_into(),
+            rx_d1.map_into(),
+            tx_d0.map_into(),
+            tx_d1.map_into(),
+            tx_en.map_into(),
         ];
 
         let mut this = Self {
@@ -316,7 +316,7 @@ struct Inner<'d, T: Instance, const TX: usize, const RX: usize> {
 }
 
 impl<'d, T: Instance, const TX: usize, const RX: usize> Inner<'d, T, TX, RX> {
-    pub fn new(_peri: impl Unborrow<Target = T> + 'd) -> Self {
+    pub fn new(_peri: impl Peripheral<P = T> + 'd) -> Self {
         Self {
             _peri: PhantomData,
             desc_ring: DescriptorRing::new(),
diff --git a/embassy-stm32/src/exti.rs b/embassy-stm32/src/exti.rs
index 94e0e941d..3b8d9390f 100644
--- a/embassy-stm32/src/exti.rs
+++ b/embassy-stm32/src/exti.rs
@@ -4,12 +4,12 @@ use core::pin::Pin;
 use core::task::{Context, Poll};
 
 use embassy::waitqueue::AtomicWaker;
-use embassy_hal_common::unsafe_impl_unborrow;
+use embassy_hal_common::impl_peripheral;
 
 use crate::gpio::{AnyPin, Input, Pin as GpioPin};
 use crate::pac::exti::regs::Lines;
 use crate::pac::EXTI;
-use crate::{interrupt, pac, peripherals, Unborrow};
+use crate::{interrupt, pac, peripherals, Peripheral};
 
 const EXTI_COUNT: usize = 16;
 const NEW_AW: AtomicWaker = AtomicWaker::new();
@@ -86,7 +86,7 @@ pub struct ExtiInput<'d, T: GpioPin> {
 impl<'d, T: GpioPin> Unpin for ExtiInput<'d, T> {}
 
 impl<'d, T: GpioPin> ExtiInput<'d, T> {
-    pub fn new(pin: Input<'d, T>, _ch: impl Unborrow<Target = T::ExtiChannel> + 'd) -> Self {
+    pub fn new(pin: Input<'d, T>, _ch: impl Peripheral<P = T::ExtiChannel> + 'd) -> Self {
         Self { pin }
     }
 
@@ -320,7 +320,7 @@ pub trait Channel: sealed::Channel + Sized {
 pub struct AnyChannel {
     number: u8,
 }
-unsafe_impl_unborrow!(AnyChannel);
+impl_peripheral!(AnyChannel);
 impl sealed::Channel for AnyChannel {}
 impl Channel for AnyChannel {
     fn number(&self) -> usize {
diff --git a/embassy-stm32/src/flash/mod.rs b/embassy-stm32/src/flash/mod.rs
index 2047f70e1..5258c9b04 100644
--- a/embassy-stm32/src/flash/mod.rs
+++ b/embassy-stm32/src/flash/mod.rs
@@ -1,11 +1,9 @@
-use core::marker::PhantomData;
-
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 use embedded_storage::nor_flash::{ErrorType, NorFlash, NorFlashError, NorFlashErrorKind, ReadNorFlash};
 
 pub use crate::pac::{ERASE_SIZE, ERASE_VALUE, FLASH_BASE, FLASH_SIZE, WRITE_SIZE};
 use crate::peripherals::FLASH;
-use crate::Unborrow;
+use crate::Peripheral;
 const FLASH_END: usize = FLASH_BASE + FLASH_SIZE;
 
 #[cfg_attr(any(flash_wl, flash_wb, flash_l0, flash_l1, flash_l4), path = "l.rs")]
@@ -16,20 +14,16 @@ const FLASH_END: usize = FLASH_BASE + FLASH_SIZE;
 mod family;
 
 pub struct Flash<'d> {
-    _inner: FLASH,
-    _phantom: PhantomData<&'d mut FLASH>,
+    _inner: PeripheralRef<'d, FLASH>,
 }
 
 impl<'d> Flash<'d> {
-    pub fn new(p: impl Unborrow<Target = FLASH>) -> Self {
-        unborrow!(p);
-        Self {
-            _inner: p,
-            _phantom: PhantomData,
-        }
+    pub fn new(p: impl Peripheral<P = FLASH> + 'd) -> Self {
+        into_ref!(p);
+        Self { _inner: p }
     }
 
-    pub fn unlock(p: impl Unborrow<Target = FLASH>) -> Self {
+    pub fn unlock(p: impl Peripheral<P = FLASH> + 'd) -> Self {
         let flash = Self::new(p);
 
         unsafe { family::unlock() };
diff --git a/embassy-stm32/src/fmc/mod.rs b/embassy-stm32/src/fmc/mod.rs
index 4f8e467d0..856a4adca 100644
--- a/embassy-stm32/src/fmc/mod.rs
+++ b/embassy-stm32/src/fmc/mod.rs
@@ -1,10 +1,10 @@
 use core::marker::PhantomData;
 
-use embassy_hal_common::unborrow;
+use embassy_hal_common::into_ref;
 
 use crate::gpio::sealed::AFType;
 use crate::gpio::{Pull, Speed};
-use crate::Unborrow;
+use crate::Peripheral;
 
 mod pins;
 pub use pins::*;
@@ -39,7 +39,7 @@ where
 
 macro_rules! config_pins {
     ($($pin:ident),*) => {
-        unborrow!($($pin),*);
+        into_ref!($($pin),*);
         $(
             $pin.set_as_af_pull($pin.af_num(), AFType::OutputPushPull, Pull::Up);
             $pin.set_speed(Speed::VeryHigh);
@@ -57,12 +57,12 @@ macro_rules! fmc_sdram_constructor {
         ctrl: [$(($ctrl_pin_name:ident: $ctrl_signal:ident)),*]
     )) => {
         pub fn $name<CHIP: stm32_fmc::SdramChip>(
-            _instance: impl Unborrow<Target = T> + 'd,
-            $($addr_pin_name: impl Unborrow<Target = impl $addr_signal<T>> + 'd),*,
-            $($ba_pin_name: impl Unborrow<Target = impl $ba_signal<T>> + 'd),*,
-            $($d_pin_name: impl Unborrow<Target = impl $d_signal<T>> + 'd),*,
-            $($nbl_pin_name: impl Unborrow<Target = impl $nbl_signal<T>> + 'd),*,
-            $($ctrl_pin_name: impl Unborrow<Target = impl $ctrl_signal<T>> + 'd),*,
+            _instance: impl Peripheral<P = T> + 'd,
+            $($addr_pin_name: impl Peripheral<P = impl $addr_signal<T>> + 'd),*,
+            $($ba_pin_name: impl Peripheral<P = impl $ba_signal<T>> + 'd),*,
+            $($d_pin_name: impl Peripheral<P = impl $d_signal<T>> + 'd),*,
+            $($nbl_pin_name: impl Peripheral<P = impl $nbl_signal<T>> + 'd),*,
+            $($ctrl_pin_name: impl Peripheral<P = impl $ctrl_signal<T>> + 'd),*,
             chip: CHIP
         ) -> stm32_fmc::Sdram<Fmc<'d, T>, CHIP> {
 
diff --git a/embassy-stm32/src/gpio.rs b/embassy-stm32/src/gpio.rs
index 1059ebf86..3c4cdb887 100644
--- a/embassy-stm32/src/gpio.rs
+++ b/embassy-stm32/src/gpio.rs
@@ -1,11 +1,10 @@
 #![macro_use]
 use core::convert::Infallible;
-use core::marker::PhantomData;
 
-use embassy_hal_common::{unborrow, unsafe_impl_unborrow};
+use embassy_hal_common::{impl_peripheral, into_ref, PeripheralRef};
 
 use crate::pac::gpio::{self, vals};
-use crate::{pac, peripherals, Unborrow};
+use crate::{pac, peripherals, Peripheral};
 
 /// GPIO flexible pin.
 ///
@@ -13,8 +12,7 @@ use crate::{pac, peripherals, Unborrow};
 /// set while not in output mode, so the pin's level will be 'remembered' when it is not in output
 /// mode.
 pub struct Flex<'d, T: Pin> {
-    pub(crate) pin: T,
-    phantom: PhantomData<&'d mut T>,
+    pub(crate) pin: PeripheralRef<'d, T>,
 }
 
 impl<'d, T: Pin> Flex<'d, T> {
@@ -24,13 +22,10 @@ impl<'d, T: Pin> Flex<'d, T> {
     /// before the pin is put into output mode.
     ///
     #[inline]
-    pub fn new(pin: impl Unborrow<Target = T> + 'd) -> Self {
-        unborrow!(pin);
+    pub fn new(pin: impl Peripheral<P = T> + 'd) -> Self {
+        into_ref!(pin);
         // Pin will be in disconnected state.
-        Self {
-            pin,
-            phantom: PhantomData,
-        }
+        Self { pin }
     }
 
     /// Put the pin into input mode.
@@ -285,7 +280,7 @@ pub struct Input<'d, T: Pin> {
 
 impl<'d, T: Pin> Input<'d, T> {
     #[inline]
-    pub fn new(pin: impl Unborrow<Target = T> + 'd, pull: Pull) -> Self {
+    pub fn new(pin: impl Peripheral<P = T> + 'd, pull: Pull) -> Self {
         let mut pin = Flex::new(pin);
         pin.set_as_input(pull);
         Self { pin }
@@ -340,7 +335,7 @@ pub struct Output<'d, T: Pin> {
 
 impl<'d, T: Pin> Output<'d, T> {
     #[inline]
-    pub fn new(pin: impl Unborrow<Target = T> + 'd, initial_output: Level, speed: Speed) -> Self {
+    pub fn new(pin: impl Peripheral<P = T> + 'd, initial_output: Level, speed: Speed) -> Self {
         let mut pin = Flex::new(pin);
         match initial_output {
             Level::High => pin.set_high(),
@@ -400,7 +395,7 @@ pub struct OutputOpenDrain<'d, T: Pin> {
 
 impl<'d, T: Pin> OutputOpenDrain<'d, T> {
     #[inline]
-    pub fn new(pin: impl Unborrow<Target = T> + 'd, initial_output: Level, speed: Speed, pull: Pull) -> Self {
+    pub fn new(pin: impl Peripheral<P = T> + 'd, initial_output: Level, speed: Speed, pull: Pull) -> Self {
         let mut pin = Flex::new(pin);
 
         match initial_output {
@@ -626,7 +621,7 @@ pub(crate) mod sealed {
     }
 }
 
-pub trait Pin: sealed::Pin + Sized + 'static {
+pub trait Pin: Peripheral<P = Self> + Into<AnyPin> + sealed::Pin + Sized + 'static {
     #[cfg(feature = "exti")]
     type ExtiChannel: crate::exti::Channel;
 
@@ -673,7 +668,7 @@ impl AnyPin {
     }
 }
 
-unsafe_impl_unborrow!(AnyPin);
+impl_peripheral!(AnyPin);
 impl Pin for AnyPin {
     #[cfg(feature = "exti")]
     type ExtiChannel = crate::exti::AnyChannel;
@@ -699,6 +694,12 @@ foreach_pin!(
                 $port_num * 16 + $pin_num
             }
         }
+
+        impl From<peripherals::$pin_name> for AnyPin {
+            fn from(x: peripherals::$pin_name) -> Self {
+                x.degrade()
+            }
+        }
     };
 );
 
diff --git a/embassy-stm32/src/i2c/v1.rs b/embassy-stm32/src/i2c/v1.rs
index 65c918780..613815a9c 100644
--- a/embassy-stm32/src/i2c/v1.rs
+++ b/embassy-stm32/src/i2c/v1.rs
@@ -1,13 +1,13 @@
 use core::marker::PhantomData;
 
 use embassy_embedded_hal::SetConfig;
-use embassy_hal_common::unborrow;
+use embassy_hal_common::into_ref;
 
 use crate::gpio::sealed::AFType;
 use crate::i2c::{Error, Instance, SclPin, SdaPin};
 use crate::pac::i2c;
 use crate::time::Hertz;
-use crate::Unborrow;
+use crate::Peripheral;
 
 pub struct State {}
 
@@ -23,12 +23,12 @@ pub struct I2c<'d, T: Instance> {
 
 impl<'d, T: Instance> I2c<'d, T> {
     pub fn new(
-        _peri: impl Unborrow<Target = T> + 'd,
-        scl: impl Unborrow<Target = impl SclPin<T>> + 'd,
-        sda: impl Unborrow<Target = impl SdaPin<T>> + 'd,
+        _peri: impl Peripheral<P = T> + 'd,
+        scl: impl Peripheral<P = impl SclPin<T>> + 'd,
+        sda: impl Peripheral<P = impl SdaPin<T>> + 'd,
         freq: Hertz,
     ) -> Self {
-        unborrow!(scl, sda);
+        into_ref!(scl, sda);
 
         T::enable();
         T::reset();
diff --git a/embassy-stm32/src/i2c/v2.rs b/embassy-stm32/src/i2c/v2.rs
index 108ea7e34..dec92cc88 100644
--- a/embassy-stm32/src/i2c/v2.rs
+++ b/embassy-stm32/src/i2c/v2.rs
@@ -1,12 +1,11 @@
 use core::cmp;
-use core::marker::PhantomData;
 use core::task::Poll;
 
 use atomic_polyfill::{AtomicUsize, Ordering};
 use embassy::waitqueue::AtomicWaker;
 use embassy_embedded_hal::SetConfig;
 use embassy_hal_common::drop::OnDrop;
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 use futures::future::poll_fn;
 
 use crate::dma::NoDma;
@@ -15,7 +14,7 @@ use crate::i2c::{Error, Instance, SclPin, SdaPin};
 use crate::interrupt::InterruptExt;
 use crate::pac::i2c;
 use crate::time::Hertz;
-use crate::Unborrow;
+use crate::Peripheral;
 
 pub struct State {
     waker: AtomicWaker,
@@ -32,23 +31,23 @@ impl State {
 }
 
 pub struct I2c<'d, T: Instance, TXDMA = NoDma, RXDMA = NoDma> {
-    phantom: PhantomData<&'d mut T>,
-    tx_dma: TXDMA,
+    _peri: PeripheralRef<'d, T>,
+    tx_dma: PeripheralRef<'d, TXDMA>,
     #[allow(dead_code)]
-    rx_dma: RXDMA,
+    rx_dma: PeripheralRef<'d, RXDMA>,
 }
 
 impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
     pub fn new(
-        _peri: impl Unborrow<Target = T> + 'd,
-        scl: impl Unborrow<Target = impl SclPin<T>> + 'd,
-        sda: impl Unborrow<Target = impl SdaPin<T>> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        tx_dma: impl Unborrow<Target = TXDMA> + 'd,
-        rx_dma: impl Unborrow<Target = RXDMA> + 'd,
+        peri: impl Peripheral<P = T> + 'd,
+        scl: impl Peripheral<P = impl SclPin<T>> + 'd,
+        sda: impl Peripheral<P = impl SdaPin<T>> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        tx_dma: impl Peripheral<P = TXDMA> + 'd,
+        rx_dma: impl Peripheral<P = RXDMA> + 'd,
         freq: Hertz,
     ) -> Self {
-        unborrow!(irq, scl, sda, tx_dma, rx_dma);
+        into_ref!(peri, irq, scl, sda, tx_dma, rx_dma);
 
         T::enable();
         T::reset();
@@ -88,7 +87,7 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
         irq.enable();
 
         Self {
-            phantom: PhantomData,
+            _peri: peri,
             tx_dma,
             rx_dma,
         }
diff --git a/embassy-stm32/src/lib.rs b/embassy-stm32/src/lib.rs
index 8b8168589..78025f3db 100644
--- a/embassy-stm32/src/lib.rs
+++ b/embassy-stm32/src/lib.rs
@@ -75,7 +75,7 @@ pub(crate) mod _generated {
 // Reexports
 pub use _generated::{peripherals, Peripherals};
 pub use embassy_cortex_m::executor;
-pub use embassy_hal_common::{unborrow, Unborrow};
+pub use embassy_hal_common::{into_ref, Peripheral, PeripheralRef};
 pub use embassy_macros::cortex_m_interrupt as interrupt;
 #[cfg(feature = "unstable-pac")]
 pub use stm32_metapac as pac;
diff --git a/embassy-stm32/src/pwm/simple_pwm.rs b/embassy-stm32/src/pwm/simple_pwm.rs
index 60aa110c7..7b2cdbc01 100644
--- a/embassy-stm32/src/pwm/simple_pwm.rs
+++ b/embassy-stm32/src/pwm/simple_pwm.rs
@@ -1,21 +1,18 @@
-use core::marker::PhantomData;
-
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 
 use super::*;
 #[allow(unused_imports)]
 use crate::gpio::sealed::{AFType, Pin};
 use crate::time::Hertz;
-use crate::Unborrow;
+use crate::Peripheral;
 
 pub struct SimplePwm<'d, T> {
-    phantom: PhantomData<&'d mut T>,
-    inner: T,
+    inner: PeripheralRef<'d, T>,
 }
 
 macro_rules! config_pins {
     ($($pin:ident),*) => {
-        unborrow!($($pin),*);
+        into_ref!($($pin),*);
         // NOTE(unsafe) Exclusive access to the registers
         critical_section::with(|_| unsafe {
             $(
@@ -30,8 +27,8 @@ macro_rules! config_pins {
 
 impl<'d, T: CaptureCompare16bitInstance> SimplePwm<'d, T> {
     pub fn new_1ch(
-        tim: impl Unborrow<Target = T> + 'd,
-        ch1: impl Unborrow<Target = impl Channel1Pin<T>> + 'd,
+        tim: impl Peripheral<P = T> + 'd,
+        ch1: impl Peripheral<P = impl Channel1Pin<T>> + 'd,
         freq: Hertz,
     ) -> Self {
         Self::new_inner(tim, freq, move || {
@@ -40,9 +37,9 @@ impl<'d, T: CaptureCompare16bitInstance> SimplePwm<'d, T> {
     }
 
     pub fn new_2ch(
-        tim: impl Unborrow<Target = T> + 'd,
-        ch1: impl Unborrow<Target = impl Channel1Pin<T>> + 'd,
-        ch2: impl Unborrow<Target = impl Channel2Pin<T>> + 'd,
+        tim: impl Peripheral<P = T> + 'd,
+        ch1: impl Peripheral<P = impl Channel1Pin<T>> + 'd,
+        ch2: impl Peripheral<P = impl Channel2Pin<T>> + 'd,
         freq: Hertz,
     ) -> Self {
         Self::new_inner(tim, freq, move || {
@@ -51,10 +48,10 @@ impl<'d, T: CaptureCompare16bitInstance> SimplePwm<'d, T> {
     }
 
     pub fn new_3ch(
-        tim: impl Unborrow<Target = T> + 'd,
-        ch1: impl Unborrow<Target = impl Channel1Pin<T>> + 'd,
-        ch2: impl Unborrow<Target = impl Channel2Pin<T>> + 'd,
-        ch3: impl Unborrow<Target = impl Channel3Pin<T>> + 'd,
+        tim: impl Peripheral<P = T> + 'd,
+        ch1: impl Peripheral<P = impl Channel1Pin<T>> + 'd,
+        ch2: impl Peripheral<P = impl Channel2Pin<T>> + 'd,
+        ch3: impl Peripheral<P = impl Channel3Pin<T>> + 'd,
         freq: Hertz,
     ) -> Self {
         Self::new_inner(tim, freq, move || {
@@ -63,11 +60,11 @@ impl<'d, T: CaptureCompare16bitInstance> SimplePwm<'d, T> {
     }
 
     pub fn new_4ch(
-        tim: impl Unborrow<Target = T> + 'd,
-        ch1: impl Unborrow<Target = impl Channel1Pin<T>> + 'd,
-        ch2: impl Unborrow<Target = impl Channel2Pin<T>> + 'd,
-        ch3: impl Unborrow<Target = impl Channel3Pin<T>> + 'd,
-        ch4: impl Unborrow<Target = impl Channel4Pin<T>> + 'd,
+        tim: impl Peripheral<P = T> + 'd,
+        ch1: impl Peripheral<P = impl Channel1Pin<T>> + 'd,
+        ch2: impl Peripheral<P = impl Channel2Pin<T>> + 'd,
+        ch3: impl Peripheral<P = impl Channel3Pin<T>> + 'd,
+        ch4: impl Peripheral<P = impl Channel4Pin<T>> + 'd,
         freq: Hertz,
     ) -> Self {
         Self::new_inner(tim, freq, move || {
@@ -75,18 +72,15 @@ impl<'d, T: CaptureCompare16bitInstance> SimplePwm<'d, T> {
         })
     }
 
-    fn new_inner(tim: impl Unborrow<Target = T> + 'd, freq: Hertz, configure_pins: impl FnOnce()) -> Self {
-        unborrow!(tim);
+    fn new_inner(tim: impl Peripheral<P = T> + 'd, freq: Hertz, configure_pins: impl FnOnce()) -> Self {
+        into_ref!(tim);
 
         T::enable();
         <T as crate::rcc::sealed::RccPeripheral>::reset();
 
         configure_pins();
 
-        let mut this = Self {
-            inner: tim,
-            phantom: PhantomData,
-        };
+        let mut this = Self { inner: tim };
 
         this.inner.set_frequency(freq);
         this.inner.start();
diff --git a/embassy-stm32/src/rcc/h7.rs b/embassy-stm32/src/rcc/h7.rs
index 6b1014312..0185f7ae8 100644
--- a/embassy-stm32/src/rcc/h7.rs
+++ b/embassy-stm32/src/rcc/h7.rs
@@ -1,6 +1,6 @@
 use core::marker::PhantomData;
 
-use embassy_hal_common::unborrow;
+use embassy_hal_common::into_ref;
 pub use pll::PllConfig;
 use stm32_metapac::rcc::vals::{Mco1, Mco2};
 
@@ -10,7 +10,7 @@ use crate::pac::rcc::vals::{Adcsel, Ckpersel, Dppre, Hpre, Hsidiv, Pllsrc, Sw, T
 use crate::pac::{PWR, RCC, SYSCFG};
 use crate::rcc::{set_freqs, Clocks};
 use crate::time::Hertz;
-use crate::{peripherals, Unborrow};
+use crate::{peripherals, Peripheral};
 
 /// HSI speed
 pub const HSI_FREQ: Hertz = Hertz(64_000_000);
@@ -385,12 +385,12 @@ pub struct Mco<'d, T: McoInstance> {
 
 impl<'d, T: McoInstance> Mco<'d, T> {
     pub fn new(
-        _peri: impl Unborrow<Target = T> + 'd,
-        pin: impl Unborrow<Target = impl McoPin<T>> + 'd,
+        _peri: impl Peripheral<P = T> + 'd,
+        pin: impl Peripheral<P = impl McoPin<T>> + 'd,
         source: impl McoSource<Raw = T::Source>,
         prescaler: McoClock,
     ) -> Self {
-        unborrow!(pin);
+        into_ref!(pin);
 
         critical_section::with(|_| unsafe {
             T::apply_clock_settings(source.into_raw(), prescaler.into_raw());
diff --git a/embassy-stm32/src/rng.rs b/embassy-stm32/src/rng.rs
index 5b3558c92..2b0ee7131 100644
--- a/embassy-stm32/src/rng.rs
+++ b/embassy-stm32/src/rng.rs
@@ -1,14 +1,13 @@
 #![macro_use]
 
-use core::marker::PhantomData;
 use core::task::Poll;
 
 use embassy::waitqueue::AtomicWaker;
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 use futures::future::poll_fn;
 use rand_core::{CryptoRng, RngCore};
 
-use crate::{pac, peripherals, Unborrow};
+use crate::{pac, peripherals, Peripheral};
 
 pub(crate) static RNG_WAKER: AtomicWaker = AtomicWaker::new();
 
@@ -19,19 +18,15 @@ pub enum Error {
 }
 
 pub struct Rng<'d, T: Instance> {
-    _inner: T,
-    _phantom: PhantomData<&'d mut T>,
+    _inner: PeripheralRef<'d, T>,
 }
 
 impl<'d, T: Instance> Rng<'d, T> {
-    pub fn new(inner: impl Unborrow<Target = T> + 'd) -> Self {
+    pub fn new(inner: impl Peripheral<P = T> + 'd) -> Self {
         T::enable();
         T::reset();
-        unborrow!(inner);
-        let mut random = Self {
-            _inner: inner,
-            _phantom: PhantomData,
-        };
+        into_ref!(inner);
+        let mut random = Self { _inner: inner };
         random.reset();
         random
     }
diff --git a/embassy-stm32/src/sdmmc/mod.rs b/embassy-stm32/src/sdmmc/mod.rs
index d94509748..b9dff8faf 100644
--- a/embassy-stm32/src/sdmmc/mod.rs
+++ b/embassy-stm32/src/sdmmc/mod.rs
@@ -1,23 +1,22 @@
 #![macro_use]
 
 use core::default::Default;
-use core::marker::PhantomData;
 use core::task::Poll;
 
 use embassy::waitqueue::AtomicWaker;
 use embassy_hal_common::drop::OnDrop;
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 use futures::future::poll_fn;
 use sdio_host::{BusWidth, CardCapacity, CardStatus, CurrentState, SDStatus, CID, CSD, OCR, SCR};
 
 use crate::dma::NoDma;
-use crate::gpio::sealed::AFType;
-use crate::gpio::{Pull, Speed};
+use crate::gpio::sealed::{AFType, Pin};
+use crate::gpio::{AnyPin, Pull, Speed};
 use crate::interrupt::{Interrupt, InterruptExt};
 use crate::pac::sdmmc::Sdmmc as RegBlock;
 use crate::rcc::RccPeripheral;
 use crate::time::Hertz;
-use crate::{peripherals, Unborrow};
+use crate::{peripherals, Peripheral};
 
 /// The signalling scheme used on the SDMMC bus
 #[non_exhaustive]
@@ -176,12 +175,19 @@ impl Default for Config {
 }
 
 /// Sdmmc device
-pub struct Sdmmc<'d, T: Instance, P: Pins<T>, Dma = NoDma> {
-    sdmmc: PhantomData<&'d mut T>,
-    pins: P,
-    irq: T::Interrupt,
+pub struct Sdmmc<'d, T: Instance, Dma = NoDma> {
+    _peri: PeripheralRef<'d, T>,
+    irq: PeripheralRef<'d, T::Interrupt>,
+    dma: PeripheralRef<'d, Dma>,
+
+    clk: PeripheralRef<'d, AnyPin>,
+    cmd: PeripheralRef<'d, AnyPin>,
+    d0: PeripheralRef<'d, AnyPin>,
+    d1: Option<PeripheralRef<'d, AnyPin>>,
+    d2: Option<PeripheralRef<'d, AnyPin>>,
+    d3: Option<PeripheralRef<'d, AnyPin>>,
+
     config: Config,
-    dma: Dma,
     /// Current clock to card
     clock: Hertz,
     /// Current signalling scheme to card
@@ -191,16 +197,99 @@ pub struct Sdmmc<'d, T: Instance, P: Pins<T>, Dma = NoDma> {
 }
 
 #[cfg(sdmmc_v1)]
-impl<'d, T: Instance, P: Pins<T>, Dma: SdmmcDma<T>> Sdmmc<'d, T, P, Dma> {
-    pub fn new(
-        _peripheral: impl Unborrow<Target = T> + 'd,
-        pins: impl Unborrow<Target = P> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
+impl<'d, T: Instance, Dma: SdmmcDma<T>> Sdmmc<'d, T, Dma> {
+    pub fn new_1bit(
+        sdmmc: impl Peripheral<P = T> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        dma: impl Peripheral<P = Dma> + 'd,
+        clk: impl Peripheral<P = impl CkPin<T>> + 'd,
+        cmd: impl Peripheral<P = impl CmdPin<T>> + 'd,
+        d0: impl Peripheral<P = impl D0Pin<T>> + 'd,
         config: Config,
-        dma: impl Unborrow<Target = Dma> + 'd,
     ) -> Self {
-        unborrow!(irq, pins, dma);
-        pins.configure();
+        into_ref!(clk, cmd, d0);
+
+        critical_section::with(|_| unsafe {
+            clk.set_as_af_pull(clk.af_num(), AFType::OutputPushPull, Pull::None);
+            cmd.set_as_af_pull(cmd.af_num(), AFType::OutputPushPull, Pull::Up);
+            d0.set_as_af_pull(d0.af_num(), AFType::OutputPushPull, Pull::Up);
+
+            clk.set_speed(Speed::VeryHigh);
+            cmd.set_speed(Speed::VeryHigh);
+            d0.set_speed(Speed::VeryHigh);
+        });
+
+        Self::new_inner(
+            sdmmc,
+            irq,
+            dma,
+            clk.map_into(),
+            cmd.map_into(),
+            d0.map_into(),
+            None,
+            None,
+            None,
+            config,
+        )
+    }
+
+    pub fn new_4bit(
+        sdmmc: impl Peripheral<P = T> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        dma: impl Peripheral<P = Dma> + 'd,
+        clk: impl Peripheral<P = impl CkPin<T>> + 'd,
+        cmd: impl Peripheral<P = impl CmdPin<T>> + 'd,
+        d0: impl Peripheral<P = impl D0Pin<T>> + 'd,
+        d1: impl Peripheral<P = impl D1Pin<T>> + 'd,
+        d2: impl Peripheral<P = impl D2Pin<T>> + 'd,
+        d3: impl Peripheral<P = impl D3Pin<T>> + 'd,
+        config: Config,
+    ) -> Self {
+        into_ref!(clk, cmd, d0, d1, d2, d3);
+
+        critical_section::with(|_| unsafe {
+            clk.set_as_af_pull(clk.af_num(), AFType::OutputPushPull, Pull::None);
+            cmd.set_as_af_pull(cmd.af_num(), AFType::OutputPushPull, Pull::Up);
+            d0.set_as_af_pull(d0.af_num(), AFType::OutputPushPull, Pull::Up);
+            d1.set_as_af_pull(d1.af_num(), AFType::OutputPushPull, Pull::Up);
+            d2.set_as_af_pull(d2.af_num(), AFType::OutputPushPull, Pull::Up);
+            d3.set_as_af_pull(d3.af_num(), AFType::OutputPushPull, Pull::Up);
+
+            clk.set_speed(Speed::VeryHigh);
+            cmd.set_speed(Speed::VeryHigh);
+            d0.set_speed(Speed::VeryHigh);
+            d1.set_speed(Speed::VeryHigh);
+            d2.set_speed(Speed::VeryHigh);
+            d3.set_speed(Speed::VeryHigh);
+        });
+
+        Self::new_inner(
+            sdmmc,
+            irq,
+            dma,
+            clk.map_into(),
+            cmd.map_into(),
+            d0.map_into(),
+            Some(d1.map_into()),
+            Some(d2.map_into()),
+            Some(d3.map_into()),
+            config,
+        )
+    }
+
+    fn new_inner(
+        sdmmc: impl Peripheral<P = T> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        dma: impl Peripheral<P = Dma> + 'd,
+        clk: PeripheralRef<'d, AnyPin>,
+        cmd: PeripheralRef<'d, AnyPin>,
+        d0: PeripheralRef<'d, AnyPin>,
+        d1: Option<PeripheralRef<'d, AnyPin>>,
+        d2: Option<PeripheralRef<'d, AnyPin>>,
+        d3: Option<PeripheralRef<'d, AnyPin>>,
+        config: Config,
+    ) -> Self {
+        into_ref!(sdmmc, irq, dma);
 
         T::enable();
         T::reset();
@@ -213,11 +302,18 @@ impl<'d, T: Instance, P: Pins<T>, Dma: SdmmcDma<T>> Sdmmc<'d, T, P, Dma> {
         irq.enable();
 
         Self {
-            sdmmc: PhantomData,
-            pins,
+            _peri: sdmmc,
             irq,
-            config,
             dma,
+
+            clk,
+            cmd,
+            d0,
+            d1,
+            d2,
+            d3,
+
+            config,
             clock,
             signalling: Default::default(),
             card: None,
@@ -226,15 +322,94 @@ impl<'d, T: Instance, P: Pins<T>, Dma: SdmmcDma<T>> Sdmmc<'d, T, P, Dma> {
 }
 
 #[cfg(sdmmc_v2)]
-impl<'d, T: Instance, P: Pins<T>> Sdmmc<'d, T, P, NoDma> {
-    pub fn new(
-        _peripheral: impl Unborrow<Target = T> + 'd,
-        pins: impl Unborrow<Target = P> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
+impl<'d, T: Instance> Sdmmc<'d, T, NoDma> {
+    pub fn new_1bit(
+        sdmmc: impl Peripheral<P = T> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        clk: impl Peripheral<P = impl CkPin<T>> + 'd,
+        cmd: impl Peripheral<P = impl CmdPin<T>> + 'd,
+        d0: impl Peripheral<P = impl D0Pin<T>> + 'd,
+        config: Config,
+    ) -> Self {
+        into_ref!(clk, cmd, d0);
+
+        critical_section::with(|_| unsafe {
+            clk.set_as_af_pull(clk.af_num(), AFType::OutputPushPull, Pull::None);
+            cmd.set_as_af_pull(cmd.af_num(), AFType::OutputPushPull, Pull::Up);
+            d0.set_as_af_pull(d0.af_num(), AFType::OutputPushPull, Pull::Up);
+
+            clk.set_speed(Speed::VeryHigh);
+            cmd.set_speed(Speed::VeryHigh);
+            d0.set_speed(Speed::VeryHigh);
+        });
+
+        Self::new_inner(
+            sdmmc,
+            irq,
+            clk.map_into(),
+            cmd.map_into(),
+            d0.map_into(),
+            None,
+            None,
+            None,
+            config,
+        )
+    }
+
+    pub fn new_4bit(
+        sdmmc: impl Peripheral<P = T> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        clk: impl Peripheral<P = impl CkPin<T>> + 'd,
+        cmd: impl Peripheral<P = impl CmdPin<T>> + 'd,
+        d0: impl Peripheral<P = impl D0Pin<T>> + 'd,
+        d1: impl Peripheral<P = impl D1Pin<T>> + 'd,
+        d2: impl Peripheral<P = impl D2Pin<T>> + 'd,
+        d3: impl Peripheral<P = impl D3Pin<T>> + 'd,
+        config: Config,
+    ) -> Self {
+        into_ref!(clk, cmd, d0, d1, d2, d3);
+
+        critical_section::with(|_| unsafe {
+            clk.set_as_af_pull(clk.af_num(), AFType::OutputPushPull, Pull::None);
+            cmd.set_as_af_pull(cmd.af_num(), AFType::OutputPushPull, Pull::Up);
+            d0.set_as_af_pull(d0.af_num(), AFType::OutputPushPull, Pull::Up);
+            d1.set_as_af_pull(d1.af_num(), AFType::OutputPushPull, Pull::Up);
+            d2.set_as_af_pull(d2.af_num(), AFType::OutputPushPull, Pull::Up);
+            d3.set_as_af_pull(d3.af_num(), AFType::OutputPushPull, Pull::Up);
+
+            clk.set_speed(Speed::VeryHigh);
+            cmd.set_speed(Speed::VeryHigh);
+            d0.set_speed(Speed::VeryHigh);
+            d1.set_speed(Speed::VeryHigh);
+            d2.set_speed(Speed::VeryHigh);
+            d3.set_speed(Speed::VeryHigh);
+        });
+
+        Self::new_inner(
+            sdmmc,
+            irq,
+            clk.map_into(),
+            cmd.map_into(),
+            d0.map_into(),
+            Some(d1.map_into()),
+            Some(d2.map_into()),
+            Some(d3.map_into()),
+            config,
+        )
+    }
+
+    fn new_inner(
+        sdmmc: impl Peripheral<P = T> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        clk: PeripheralRef<'d, AnyPin>,
+        cmd: PeripheralRef<'d, AnyPin>,
+        d0: PeripheralRef<'d, AnyPin>,
+        d1: Option<PeripheralRef<'d, AnyPin>>,
+        d2: Option<PeripheralRef<'d, AnyPin>>,
+        d3: Option<PeripheralRef<'d, AnyPin>>,
         config: Config,
     ) -> Self {
-        unborrow!(irq, pins);
-        pins.configure();
+        into_ref!(sdmmc, irq);
 
         T::enable();
         T::reset();
@@ -247,11 +422,18 @@ impl<'d, T: Instance, P: Pins<T>> Sdmmc<'d, T, P, NoDma> {
         irq.enable();
 
         Self {
-            sdmmc: PhantomData,
-            pins,
+            _peri: sdmmc,
             irq,
+            dma: NoDma.into_ref(),
+
+            clk,
+            cmd,
+            d0,
+            d1,
+            d2,
+            d3,
+
             config,
-            dma: NoDma,
             clock,
             signalling: Default::default(),
             card: None,
@@ -259,23 +441,28 @@ impl<'d, T: Instance, P: Pins<T>> Sdmmc<'d, T, P, NoDma> {
     }
 }
 
-impl<'d, T: Instance, P: Pins<T>, Dma: SdmmcDma<T>> Sdmmc<'d, T, P, Dma> {
+impl<'d, T: Instance, Dma: SdmmcDma<T>> Sdmmc<'d, T, Dma> {
     #[inline(always)]
     pub async fn init_card(&mut self, freq: Hertz) -> Result<(), Error> {
         let inner = T::inner();
         let freq = freq.into();
 
+        let bus_width = match self.d3.is_some() {
+            true => BusWidth::Four,
+            false => BusWidth::One,
+        };
+
         inner
             .init_card(
                 freq,
-                P::BUSWIDTH,
+                bus_width,
                 &mut self.card,
                 &mut self.signalling,
                 T::frequency(),
                 &mut self.clock,
                 T::state(),
                 self.config.data_transfer_timeout,
-                &mut self.dma,
+                &mut *self.dma,
             )
             .await
     }
@@ -295,7 +482,7 @@ impl<'d, T: Instance, P: Pins<T>, Dma: SdmmcDma<T>> Sdmmc<'d, T, P, Dma> {
                 card_capacity,
                 state,
                 self.config.data_transfer_timeout,
-                &mut self.dma,
+                &mut *self.dma,
             )
             .await
     }
@@ -314,7 +501,7 @@ impl<'d, T: Instance, P: Pins<T>, Dma: SdmmcDma<T>> Sdmmc<'d, T, P, Dma> {
                 card,
                 state,
                 self.config.data_transfer_timeout,
-                &mut self.dma,
+                &mut *self.dma,
             )
             .await
     }
@@ -345,12 +532,26 @@ impl<'d, T: Instance, P: Pins<T>, Dma: SdmmcDma<T>> Sdmmc<'d, T, P, Dma> {
     }
 }
 
-impl<'d, T: Instance, P: Pins<T>, Dma> Drop for Sdmmc<'d, T, P, Dma> {
+impl<'d, T: Instance, Dma> Drop for Sdmmc<'d, T, Dma> {
     fn drop(&mut self) {
         self.irq.disable();
         let inner = T::inner();
         unsafe { inner.on_drop() };
-        self.pins.deconfigure();
+
+        critical_section::with(|_| unsafe {
+            self.clk.set_as_disconnected();
+            self.cmd.set_as_disconnected();
+            self.d0.set_as_disconnected();
+            if let Some(x) = &mut self.d1 {
+                x.set_as_disconnected();
+            }
+            if let Some(x) = &mut self.d2 {
+                x.set_as_disconnected();
+            }
+            if let Some(x) = &mut self.d3 {
+                x.set_as_disconnected();
+            }
+        });
     }
 }
 
@@ -1296,114 +1497,6 @@ cfg_if::cfg_if! {
     }
 }
 
-pub trait Pins<T: Instance>: sealed::Pins<T> + 'static {
-    const BUSWIDTH: BusWidth;
-
-    fn configure(&mut self);
-    fn deconfigure(&mut self);
-}
-
-impl<T, CLK, CMD, D0, D1, D2, D3> sealed::Pins<T> for (CLK, CMD, D0, D1, D2, D3)
-where
-    T: Instance,
-    CLK: CkPin<T>,
-    CMD: CmdPin<T>,
-    D0: D0Pin<T>,
-    D1: D1Pin<T>,
-    D2: D2Pin<T>,
-    D3: D3Pin<T>,
-{
-}
-
-impl<T, CLK, CMD, D0> sealed::Pins<T> for (CLK, CMD, D0)
-where
-    T: Instance,
-    CLK: CkPin<T>,
-    CMD: CmdPin<T>,
-    D0: D0Pin<T>,
-{
-}
-
-impl<T, CLK, CMD, D0, D1, D2, D3> Pins<T> for (CLK, CMD, D0, D1, D2, D3)
-where
-    T: Instance,
-    CLK: CkPin<T>,
-    CMD: CmdPin<T>,
-    D0: D0Pin<T>,
-    D1: D1Pin<T>,
-    D2: D2Pin<T>,
-    D3: D3Pin<T>,
-{
-    const BUSWIDTH: BusWidth = BusWidth::Four;
-
-    fn configure(&mut self) {
-        let (clk_pin, cmd_pin, d0_pin, d1_pin, d2_pin, d3_pin) = self;
-
-        critical_section::with(|_| unsafe {
-            clk_pin.set_as_af_pull(clk_pin.af_num(), AFType::OutputPushPull, Pull::None);
-            cmd_pin.set_as_af_pull(cmd_pin.af_num(), AFType::OutputPushPull, Pull::Up);
-            d0_pin.set_as_af_pull(d0_pin.af_num(), AFType::OutputPushPull, Pull::Up);
-            d1_pin.set_as_af_pull(d1_pin.af_num(), AFType::OutputPushPull, Pull::Up);
-            d2_pin.set_as_af_pull(d2_pin.af_num(), AFType::OutputPushPull, Pull::Up);
-            d3_pin.set_as_af_pull(d3_pin.af_num(), AFType::OutputPushPull, Pull::Up);
-
-            clk_pin.set_speed(Speed::VeryHigh);
-            cmd_pin.set_speed(Speed::VeryHigh);
-            d0_pin.set_speed(Speed::VeryHigh);
-            d1_pin.set_speed(Speed::VeryHigh);
-            d2_pin.set_speed(Speed::VeryHigh);
-            d3_pin.set_speed(Speed::VeryHigh);
-        });
-    }
-
-    fn deconfigure(&mut self) {
-        let (clk_pin, cmd_pin, d0_pin, d1_pin, d2_pin, d3_pin) = self;
-
-        critical_section::with(|_| unsafe {
-            clk_pin.set_as_disconnected();
-            cmd_pin.set_as_disconnected();
-            d0_pin.set_as_disconnected();
-            d1_pin.set_as_disconnected();
-            d2_pin.set_as_disconnected();
-            d3_pin.set_as_disconnected();
-        });
-    }
-}
-
-impl<T, CLK, CMD, D0> Pins<T> for (CLK, CMD, D0)
-where
-    T: Instance,
-    CLK: CkPin<T>,
-    CMD: CmdPin<T>,
-    D0: D0Pin<T>,
-{
-    const BUSWIDTH: BusWidth = BusWidth::One;
-
-    fn configure(&mut self) {
-        let (clk_pin, cmd_pin, d0_pin) = self;
-
-        critical_section::with(|_| unsafe {
-            clk_pin.set_as_af_pull(clk_pin.af_num(), AFType::OutputPushPull, Pull::None);
-            cmd_pin.set_as_af_pull(cmd_pin.af_num(), AFType::OutputPushPull, Pull::Up);
-            d0_pin.set_as_af_pull(d0_pin.af_num(), AFType::OutputPushPull, Pull::Up);
-
-            clk_pin.set_speed(Speed::VeryHigh);
-            cmd_pin.set_speed(Speed::VeryHigh);
-            d0_pin.set_speed(Speed::VeryHigh);
-        });
-    }
-
-    fn deconfigure(&mut self) {
-        let (clk_pin, cmd_pin, d0_pin) = self;
-
-        critical_section::with(|_| unsafe {
-            clk_pin.set_as_disconnected();
-            cmd_pin.set_as_disconnected();
-            d0_pin.set_as_disconnected();
-        });
-    }
-}
-
 foreach_peripheral!(
     (sdmmc, $inst:ident) => {
         impl sealed::Instance for peripherals::$inst {
diff --git a/embassy-stm32/src/spi/mod.rs b/embassy-stm32/src/spi/mod.rs
index a02f4492f..26fb392ef 100644
--- a/embassy-stm32/src/spi/mod.rs
+++ b/embassy-stm32/src/spi/mod.rs
@@ -1,10 +1,9 @@
 #![macro_use]
 
-use core::marker::PhantomData;
 use core::ptr;
 
 use embassy_embedded_hal::SetConfig;
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 pub use embedded_hal_02::spi::{Mode, Phase, Polarity, MODE_0, MODE_1, MODE_2, MODE_3};
 use futures::future::join;
 
@@ -15,7 +14,7 @@ use crate::gpio::AnyPin;
 use crate::pac::spi::{regs, vals, Spi as Regs};
 use crate::rcc::RccPeripheral;
 use crate::time::Hertz;
-use crate::{peripherals, Unborrow};
+use crate::{peripherals, Peripheral};
 
 #[derive(Debug)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
@@ -73,27 +72,27 @@ impl Config {
 }
 
 pub struct Spi<'d, T: Instance, Tx, Rx> {
-    sck: Option<AnyPin>,
-    mosi: Option<AnyPin>,
-    miso: Option<AnyPin>,
-    txdma: Tx,
-    rxdma: Rx,
+    _peri: PeripheralRef<'d, T>,
+    sck: Option<PeripheralRef<'d, AnyPin>>,
+    mosi: Option<PeripheralRef<'d, AnyPin>>,
+    miso: Option<PeripheralRef<'d, AnyPin>>,
+    txdma: PeripheralRef<'d, Tx>,
+    rxdma: PeripheralRef<'d, Rx>,
     current_word_size: WordSize,
-    phantom: PhantomData<&'d mut T>,
 }
 
 impl<'d, T: Instance, Tx, Rx> Spi<'d, T, Tx, Rx> {
     pub fn new(
-        peri: impl Unborrow<Target = T> + 'd,
-        sck: impl Unborrow<Target = impl SckPin<T>> + 'd,
-        mosi: impl Unborrow<Target = impl MosiPin<T>> + 'd,
-        miso: impl Unborrow<Target = impl MisoPin<T>> + 'd,
-        txdma: impl Unborrow<Target = Tx> + 'd,
-        rxdma: impl Unborrow<Target = Rx> + 'd,
+        peri: impl Peripheral<P = T> + 'd,
+        sck: impl Peripheral<P = impl SckPin<T>> + 'd,
+        mosi: impl Peripheral<P = impl MosiPin<T>> + 'd,
+        miso: impl Peripheral<P = impl MisoPin<T>> + 'd,
+        txdma: impl Peripheral<P = Tx> + 'd,
+        rxdma: impl Peripheral<P = Rx> + 'd,
         freq: Hertz,
         config: Config,
     ) -> Self {
-        unborrow!(sck, mosi, miso);
+        into_ref!(peri, sck, mosi, miso);
         unsafe {
             sck.set_as_af(sck.af_num(), AFType::OutputPushPull);
             #[cfg(any(spi_v2, spi_v3, spi_v4))]
@@ -108,9 +107,9 @@ impl<'d, T: Instance, Tx, Rx> Spi<'d, T, Tx, Rx> {
 
         Self::new_inner(
             peri,
-            Some(sck.degrade()),
-            Some(mosi.degrade()),
-            Some(miso.degrade()),
+            Some(sck.map_into()),
+            Some(mosi.map_into()),
+            Some(miso.map_into()),
             txdma,
             rxdma,
             freq,
@@ -119,15 +118,15 @@ impl<'d, T: Instance, Tx, Rx> Spi<'d, T, Tx, Rx> {
     }
 
     pub fn new_rxonly(
-        peri: impl Unborrow<Target = T> + 'd,
-        sck: impl Unborrow<Target = impl SckPin<T>> + 'd,
-        miso: impl Unborrow<Target = impl MisoPin<T>> + 'd,
-        txdma: impl Unborrow<Target = Tx> + 'd, // TODO remove
-        rxdma: impl Unborrow<Target = Rx> + 'd,
+        peri: impl Peripheral<P = T> + 'd,
+        sck: impl Peripheral<P = impl SckPin<T>> + 'd,
+        miso: impl Peripheral<P = impl MisoPin<T>> + 'd,
+        txdma: impl Peripheral<P = Tx> + 'd, // TODO remove
+        rxdma: impl Peripheral<P = Rx> + 'd,
         freq: Hertz,
         config: Config,
     ) -> Self {
-        unborrow!(sck, miso);
+        into_ref!(sck, miso);
         unsafe {
             sck.set_as_af(sck.af_num(), AFType::OutputPushPull);
             #[cfg(any(spi_v2, spi_v3, spi_v4))]
@@ -139,9 +138,9 @@ impl<'d, T: Instance, Tx, Rx> Spi<'d, T, Tx, Rx> {
 
         Self::new_inner(
             peri,
-            Some(sck.degrade()),
+            Some(sck.map_into()),
             None,
-            Some(miso.degrade()),
+            Some(miso.map_into()),
             txdma,
             rxdma,
             freq,
@@ -150,15 +149,15 @@ impl<'d, T: Instance, Tx, Rx> Spi<'d, T, Tx, Rx> {
     }
 
     pub fn new_txonly(
-        peri: impl Unborrow<Target = T> + 'd,
-        sck: impl Unborrow<Target = impl SckPin<T>> + 'd,
-        mosi: impl Unborrow<Target = impl MosiPin<T>> + 'd,
-        txdma: impl Unborrow<Target = Tx> + 'd,
-        rxdma: impl Unborrow<Target = Rx> + 'd, // TODO remove
+        peri: impl Peripheral<P = T> + 'd,
+        sck: impl Peripheral<P = impl SckPin<T>> + 'd,
+        mosi: impl Peripheral<P = impl MosiPin<T>> + 'd,
+        txdma: impl Peripheral<P = Tx> + 'd,
+        rxdma: impl Peripheral<P = Rx> + 'd, // TODO remove
         freq: Hertz,
         config: Config,
     ) -> Self {
-        unborrow!(sck, mosi);
+        into_ref!(sck, mosi);
         unsafe {
             sck.set_as_af(sck.af_num(), AFType::OutputPushPull);
             #[cfg(any(spi_v2, spi_v3, spi_v4))]
@@ -170,8 +169,8 @@ impl<'d, T: Instance, Tx, Rx> Spi<'d, T, Tx, Rx> {
 
         Self::new_inner(
             peri,
-            Some(sck.degrade()),
-            Some(mosi.degrade()),
+            Some(sck.map_into()),
+            Some(mosi.map_into()),
             None,
             txdma,
             rxdma,
@@ -181,16 +180,16 @@ impl<'d, T: Instance, Tx, Rx> Spi<'d, T, Tx, Rx> {
     }
 
     fn new_inner(
-        _peri: impl Unborrow<Target = T> + 'd,
-        sck: Option<AnyPin>,
-        mosi: Option<AnyPin>,
-        miso: Option<AnyPin>,
-        txdma: impl Unborrow<Target = Tx> + 'd,
-        rxdma: impl Unborrow<Target = Rx> + 'd,
+        peri: impl Peripheral<P = T> + 'd,
+        sck: Option<PeripheralRef<'d, AnyPin>>,
+        mosi: Option<PeripheralRef<'d, AnyPin>>,
+        miso: Option<PeripheralRef<'d, AnyPin>>,
+        txdma: impl Peripheral<P = Tx> + 'd,
+        rxdma: impl Peripheral<P = Rx> + 'd,
         freq: Hertz,
         config: Config,
     ) -> Self {
-        unborrow!(txdma, rxdma);
+        into_ref!(peri, txdma, rxdma);
 
         let pclk = T::frequency();
         let br = compute_baud_rate(pclk, freq.into());
@@ -280,13 +279,13 @@ impl<'d, T: Instance, Tx, Rx> Spi<'d, T, Tx, Rx> {
         }
 
         Self {
+            _peri: peri,
             sck,
             mosi,
             miso,
             txdma,
             rxdma,
             current_word_size: WordSize::EightBit,
-            phantom: PhantomData,
         }
     }
 
@@ -995,7 +994,7 @@ pub trait Word: Copy + 'static + sealed::Word + Default + crate::dma::Word {}
 impl Word for u8 {}
 impl Word for u16 {}
 
-pub trait Instance: sealed::Instance + RccPeripheral {}
+pub trait Instance: Peripheral<P = Self> + sealed::Instance + RccPeripheral {}
 pin_trait!(SckPin, Instance);
 pin_trait!(MosiPin, Instance);
 pin_trait!(MisoPin, Instance);
diff --git a/embassy-stm32/src/subghz/mod.rs b/embassy-stm32/src/subghz/mod.rs
index ce513ec63..f02fc140f 100644
--- a/embassy-stm32/src/subghz/mod.rs
+++ b/embassy-stm32/src/subghz/mod.rs
@@ -83,7 +83,7 @@ use crate::peripherals::SUBGHZSPI;
 use crate::rcc::sealed::RccPeripheral;
 use crate::spi::{BitOrder, Config as SpiConfig, MisoPin, MosiPin, SckPin, Spi, MODE_0};
 use crate::time::Hertz;
-use crate::{pac, Unborrow};
+use crate::{pac, Peripheral};
 
 /// Passthrough for SPI errors (for now)
 pub type Error = crate::spi::Error;
@@ -211,12 +211,12 @@ impl<'d, Tx, Rx> SubGhz<'d, Tx, Rx> {
     /// This will reset the radio and the SPI bus, and enable the peripheral
     /// clock.
     pub fn new(
-        peri: impl Unborrow<Target = SUBGHZSPI> + 'd,
-        sck: impl Unborrow<Target = impl SckPin<SUBGHZSPI>> + 'd,
-        mosi: impl Unborrow<Target = impl MosiPin<SUBGHZSPI>> + 'd,
-        miso: impl Unborrow<Target = impl MisoPin<SUBGHZSPI>> + 'd,
-        txdma: impl Unborrow<Target = Tx> + 'd,
-        rxdma: impl Unborrow<Target = Rx> + 'd,
+        peri: impl Peripheral<P = SUBGHZSPI> + 'd,
+        sck: impl Peripheral<P = impl SckPin<SUBGHZSPI>> + 'd,
+        mosi: impl Peripheral<P = impl MosiPin<SUBGHZSPI>> + 'd,
+        miso: impl Peripheral<P = impl MisoPin<SUBGHZSPI>> + 'd,
+        txdma: impl Peripheral<P = Tx> + 'd,
+        rxdma: impl Peripheral<P = Rx> + 'd,
     ) -> Self {
         Self::pulse_radio_reset();
 
diff --git a/embassy-stm32/src/usart/buffered.rs b/embassy-stm32/src/usart/buffered.rs
index c4703cff2..4e47ef73d 100644
--- a/embassy-stm32/src/usart/buffered.rs
+++ b/embassy-stm32/src/usart/buffered.rs
@@ -39,11 +39,11 @@ impl<'d, T: Instance> BufferedUart<'d, T> {
     pub fn new(
         state: &'d mut State<'d, T>,
         _uart: Uart<'d, T, NoDma, NoDma>,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
         tx_buffer: &'d mut [u8],
         rx_buffer: &'d mut [u8],
     ) -> BufferedUart<'d, T> {
-        unborrow!(irq);
+        into_ref!(irq);
 
         let r = T::regs();
         unsafe {
diff --git a/embassy-stm32/src/usart/mod.rs b/embassy-stm32/src/usart/mod.rs
index a893e4b80..ca75bab41 100644
--- a/embassy-stm32/src/usart/mod.rs
+++ b/embassy-stm32/src/usart/mod.rs
@@ -2,14 +2,14 @@
 
 use core::marker::PhantomData;
 
-use embassy_hal_common::unborrow;
+use embassy_hal_common::{into_ref, PeripheralRef};
 
 use crate::dma::NoDma;
 use crate::gpio::sealed::AFType;
 use crate::interrupt::Interrupt;
 use crate::pac::usart::{regs, vals};
 use crate::rcc::RccPeripheral;
-use crate::{peripherals, Unborrow};
+use crate::{peripherals, Peripheral};
 
 #[derive(Clone, Copy, PartialEq, Eq, Debug)]
 pub enum DataBits {
@@ -72,23 +72,22 @@ pub enum Error {
 }
 
 pub struct Uart<'d, T: Instance, TxDma = NoDma, RxDma = NoDma> {
-    phantom: PhantomData<&'d mut T>,
     tx: UartTx<'d, T, TxDma>,
     rx: UartRx<'d, T, RxDma>,
 }
 
 pub struct UartTx<'d, T: Instance, TxDma = NoDma> {
     phantom: PhantomData<&'d mut T>,
-    tx_dma: TxDma,
+    tx_dma: PeripheralRef<'d, TxDma>,
 }
 
 pub struct UartRx<'d, T: Instance, RxDma = NoDma> {
     phantom: PhantomData<&'d mut T>,
-    rx_dma: RxDma,
+    rx_dma: PeripheralRef<'d, RxDma>,
 }
 
 impl<'d, T: Instance, TxDma> UartTx<'d, T, TxDma> {
-    fn new(tx_dma: TxDma) -> Self {
+    fn new(tx_dma: PeripheralRef<'d, TxDma>) -> Self {
         Self {
             tx_dma,
             phantom: PhantomData,
@@ -134,7 +133,7 @@ impl<'d, T: Instance, TxDma> UartTx<'d, T, TxDma> {
 }
 
 impl<'d, T: Instance, RxDma> UartRx<'d, T, RxDma> {
-    fn new(rx_dma: RxDma) -> Self {
+    fn new(rx_dma: PeripheralRef<'d, RxDma>) -> Self {
         Self {
             rx_dma,
             phantom: PhantomData,
@@ -190,14 +189,14 @@ impl<'d, T: Instance, RxDma> UartRx<'d, T, RxDma> {
 
 impl<'d, T: Instance, TxDma, RxDma> Uart<'d, T, TxDma, RxDma> {
     pub fn new(
-        _inner: impl Unborrow<Target = T> + 'd,
-        rx: impl Unborrow<Target = impl RxPin<T>> + 'd,
-        tx: impl Unborrow<Target = impl TxPin<T>> + 'd,
-        tx_dma: impl Unborrow<Target = TxDma> + 'd,
-        rx_dma: impl Unborrow<Target = RxDma> + 'd,
+        _inner: impl Peripheral<P = T> + 'd,
+        rx: impl Peripheral<P = impl RxPin<T>> + 'd,
+        tx: impl Peripheral<P = impl TxPin<T>> + 'd,
+        tx_dma: impl Peripheral<P = TxDma> + 'd,
+        rx_dma: impl Peripheral<P = RxDma> + 'd,
         config: Config,
     ) -> Self {
-        unborrow!(_inner, rx, tx, tx_dma, rx_dma);
+        into_ref!(_inner, rx, tx, tx_dma, rx_dma);
 
         T::enable();
         T::reset();
@@ -234,7 +233,6 @@ impl<'d, T: Instance, TxDma, RxDma> Uart<'d, T, TxDma, RxDma> {
         }
 
         Self {
-            phantom: PhantomData,
             tx: UartTx::new(tx_dma),
             rx: UartRx::new(rx_dma),
         }
diff --git a/embassy-stm32/src/usb/usb.rs b/embassy-stm32/src/usb/usb.rs
index 4633ff00c..11ef75954 100644
--- a/embassy-stm32/src/usb/usb.rs
+++ b/embassy-stm32/src/usb/usb.rs
@@ -7,7 +7,7 @@ use core::task::Poll;
 use atomic_polyfill::{AtomicBool, AtomicU8};
 use embassy::time::{block_for, Duration};
 use embassy::waitqueue::AtomicWaker;
-use embassy_hal_common::unborrow;
+use embassy_hal_common::into_ref;
 use embassy_usb::driver::{self, EndpointAllocError, EndpointError, Event, Unsupported};
 use embassy_usb::types::{EndpointAddress, EndpointInfo, EndpointType, UsbDirection};
 use futures::future::poll_fn;
@@ -20,7 +20,7 @@ use crate::gpio::sealed::AFType;
 use crate::interrupt::InterruptExt;
 use crate::pac::usb::regs;
 use crate::rcc::sealed::RccPeripheral;
-use crate::{pac, Unborrow};
+use crate::{pac, Peripheral};
 
 const EP_COUNT: usize = 8;
 
@@ -125,12 +125,12 @@ pub struct Driver<'d, T: Instance> {
 
 impl<'d, T: Instance> Driver<'d, T> {
     pub fn new(
-        _usb: impl Unborrow<Target = T> + 'd,
-        irq: impl Unborrow<Target = T::Interrupt> + 'd,
-        dp: impl Unborrow<Target = impl DpPin<T>> + 'd,
-        dm: impl Unborrow<Target = impl DmPin<T>> + 'd,
+        _usb: impl Peripheral<P = T> + 'd,
+        irq: impl Peripheral<P = T::Interrupt> + 'd,
+        dp: impl Peripheral<P = impl DpPin<T>> + 'd,
+        dm: impl Peripheral<P = impl DmPin<T>> + 'd,
     ) -> Self {
-        unborrow!(irq, dp, dm);
+        into_ref!(irq, dp, dm);
         irq.set_handler(Self::on_interrupt);
         irq.unpend();
         irq.enable();
diff --git a/embassy-stm32/src/usb_otg.rs b/embassy-stm32/src/usb_otg.rs
index 581754135..f7faf12a8 100644
--- a/embassy-stm32/src/usb_otg.rs
+++ b/embassy-stm32/src/usb_otg.rs
@@ -1,14 +1,14 @@
 use core::marker::PhantomData;
 
-use embassy_hal_common::unborrow;
+use embassy_hal_common::into_ref;
 
 use crate::gpio::sealed::AFType;
 use crate::rcc::RccPeripheral;
-use crate::{peripherals, Unborrow};
+use crate::{peripherals, Peripheral};
 
 macro_rules! config_ulpi_pins {
     ($($pin:ident),*) => {
-        unborrow!($($pin),*);
+        into_ref!($($pin),*);
         // NOTE(unsafe) Exclusive access to the registers
         critical_section::with(|_| unsafe {
             $(
@@ -43,11 +43,11 @@ pub struct UsbOtg<'d, T: Instance> {
 impl<'d, T: Instance> UsbOtg<'d, T> {
     /// Initializes USB OTG peripheral with internal Full-Speed PHY
     pub fn new_fs(
-        _peri: impl Unborrow<Target = T> + 'd,
-        dp: impl Unborrow<Target = impl DpPin<T>> + 'd,
-        dm: impl Unborrow<Target = impl DmPin<T>> + 'd,
+        _peri: impl Peripheral<P = T> + 'd,
+        dp: impl Peripheral<P = impl DpPin<T>> + 'd,
+        dm: impl Peripheral<P = impl DmPin<T>> + 'd,
     ) -> Self {
-        unborrow!(dp, dm);
+        into_ref!(dp, dm);
 
         unsafe {
             dp.set_as_af(dp.af_num(), AFType::OutputPushPull);
@@ -62,19 +62,19 @@ impl<'d, T: Instance> UsbOtg<'d, T> {
 
     /// Initializes USB OTG peripheral with external High-Speed PHY
     pub fn new_hs_ulpi(
-        _peri: impl Unborrow<Target = T> + 'd,
-        ulpi_clk: impl Unborrow<Target = impl UlpiClkPin<T>> + 'd,
-        ulpi_dir: impl Unborrow<Target = impl UlpiDirPin<T>> + 'd,
-        ulpi_nxt: impl Unborrow<Target = impl UlpiNxtPin<T>> + 'd,
-        ulpi_stp: impl Unborrow<Target = impl UlpiStpPin<T>> + 'd,
-        ulpi_d0: impl Unborrow<Target = impl UlpiD0Pin<T>> + 'd,
-        ulpi_d1: impl Unborrow<Target = impl UlpiD1Pin<T>> + 'd,
-        ulpi_d2: impl Unborrow<Target = impl UlpiD2Pin<T>> + 'd,
-        ulpi_d3: impl Unborrow<Target = impl UlpiD3Pin<T>> + 'd,
-        ulpi_d4: impl Unborrow<Target = impl UlpiD4Pin<T>> + 'd,
-        ulpi_d5: impl Unborrow<Target = impl UlpiD5Pin<T>> + 'd,
-        ulpi_d6: impl Unborrow<Target = impl UlpiD6Pin<T>> + 'd,
-        ulpi_d7: impl Unborrow<Target = impl UlpiD7Pin<T>> + 'd,
+        _peri: impl Peripheral<P = T> + 'd,
+        ulpi_clk: impl Peripheral<P = impl UlpiClkPin<T>> + 'd,
+        ulpi_dir: impl Peripheral<P = impl UlpiDirPin<T>> + 'd,
+        ulpi_nxt: impl Peripheral<P = impl UlpiNxtPin<T>> + 'd,
+        ulpi_stp: impl Peripheral<P = impl UlpiStpPin<T>> + 'd,
+        ulpi_d0: impl Peripheral<P = impl UlpiD0Pin<T>> + 'd,
+        ulpi_d1: impl Peripheral<P = impl UlpiD1Pin<T>> + 'd,
+        ulpi_d2: impl Peripheral<P = impl UlpiD2Pin<T>> + 'd,
+        ulpi_d3: impl Peripheral<P = impl UlpiD3Pin<T>> + 'd,
+        ulpi_d4: impl Peripheral<P = impl UlpiD4Pin<T>> + 'd,
+        ulpi_d5: impl Peripheral<P = impl UlpiD5Pin<T>> + 'd,
+        ulpi_d6: impl Peripheral<P = impl UlpiD6Pin<T>> + 'd,
+        ulpi_d7: impl Peripheral<P = impl UlpiD7Pin<T>> + 'd,
     ) -> Self {
         config_ulpi_pins!(
             ulpi_clk, ulpi_dir, ulpi_nxt, ulpi_stp, ulpi_d0, ulpi_d1, ulpi_d2, ulpi_d3, ulpi_d4, ulpi_d5, ulpi_d6,
diff --git a/embassy-stm32/src/wdg/mod.rs b/embassy-stm32/src/wdg/mod.rs
index c4b2609b1..85176eefc 100644
--- a/embassy-stm32/src/wdg/mod.rs
+++ b/embassy-stm32/src/wdg/mod.rs
@@ -1,6 +1,6 @@
 use core::marker::PhantomData;
 
-use embassy_hal_common::{unborrow, Unborrow};
+use embassy_hal_common::{into_ref, Peripheral};
 use stm32_metapac::iwdg::vals::{Key, Pr};
 
 use crate::rcc::LSI_FREQ;
@@ -27,8 +27,8 @@ impl<'d, T: Instance> IndependentWatchdog<'d, T> {
     ///
     /// [Self] has to be started with [Self::unleash()].
     /// Once timer expires, MCU will be reset. To prevent this, timer must be reloaded by repeatedly calling [Self::pet()] within timeout interval.
-    pub fn new(_instance: impl Unborrow<Target = T> + 'd, timeout_us: u32) -> Self {
-        unborrow!(_instance);
+    pub fn new(_instance: impl Peripheral<P = T> + 'd, timeout_us: u32) -> Self {
+        into_ref!(_instance);
 
         // Find lowest prescaler value, which makes watchdog period longer or equal to timeout.
         // This iterates from 4 (2^2) to 256 (2^8).
diff --git a/examples/stm32f4/src/bin/sdmmc.rs b/examples/stm32f4/src/bin/sdmmc.rs
index 665670261..752ad57bf 100644
--- a/examples/stm32f4/src/bin/sdmmc.rs
+++ b/examples/stm32f4/src/bin/sdmmc.rs
@@ -21,12 +21,17 @@ async fn main(_spawner: Spawner, p: Peripherals) -> ! {
 
     let irq = interrupt::take!(SDIO);
 
-    let mut sdmmc = Sdmmc::new(
+    let mut sdmmc = Sdmmc::new_4bit(
         p.SDIO,
-        (p.PC12, p.PD2, p.PC8, p.PC9, p.PC10, p.PC11),
         irq,
-        Default::default(),
         p.DMA2_CH3,
+        p.PC12,
+        p.PD2,
+        p.PC8,
+        p.PC9,
+        p.PC10,
+        p.PC11,
+        Default::default(),
     );
 
     // Should print 400kHz for initialization
diff --git a/examples/stm32f7/src/bin/sdmmc.rs b/examples/stm32f7/src/bin/sdmmc.rs
index 011e1fd95..be1c2b152 100644
--- a/examples/stm32f7/src/bin/sdmmc.rs
+++ b/examples/stm32f7/src/bin/sdmmc.rs
@@ -21,12 +21,17 @@ async fn main(_spawner: Spawner, p: Peripherals) -> ! {
 
     let irq = interrupt::take!(SDMMC1);
 
-    let mut sdmmc = Sdmmc::new(
+    let mut sdmmc = Sdmmc::new_4bit(
         p.SDMMC1,
-        (p.PC12, p.PD2, p.PC8, p.PC9, p.PC10, p.PC11),
         irq,
-        Default::default(),
         p.DMA2_CH3,
+        p.PC12,
+        p.PD2,
+        p.PC8,
+        p.PC9,
+        p.PC10,
+        p.PC11,
+        Default::default(),
     );
 
     // Should print 400kHz for initialization
diff --git a/examples/stm32h7/src/bin/low_level_timer_api.rs b/examples/stm32h7/src/bin/low_level_timer_api.rs
index fc19d84e4..d7c6da5bd 100644
--- a/examples/stm32h7/src/bin/low_level_timer_api.rs
+++ b/examples/stm32h7/src/bin/low_level_timer_api.rs
@@ -2,8 +2,6 @@
 #![no_main]
 #![feature(type_alias_impl_trait)]
 
-use core::marker::PhantomData;
-
 use defmt::*;
 use embassy::executor::Spawner;
 use embassy::time::{Duration, Timer};
@@ -11,7 +9,7 @@ use embassy_stm32::gpio::low_level::AFType;
 use embassy_stm32::gpio::Speed;
 use embassy_stm32::pwm::*;
 use embassy_stm32::time::{khz, mhz, Hertz};
-use embassy_stm32::{unborrow, Config, Peripherals, Unborrow};
+use embassy_stm32::{into_ref, Config, Peripheral, PeripheralRef, Peripherals};
 use {defmt_rtt as _, panic_probe as _};
 
 pub fn config() -> Config {
@@ -49,20 +47,19 @@ async fn main(_spawner: Spawner, p: Peripherals) {
     }
 }
 pub struct SimplePwm32<'d, T: CaptureCompare32bitInstance> {
-    phantom: PhantomData<&'d mut T>,
-    inner: T,
+    inner: PeripheralRef<'d, T>,
 }
 
 impl<'d, T: CaptureCompare32bitInstance> SimplePwm32<'d, T> {
     pub fn new(
-        tim: impl Unborrow<Target = T> + 'd,
-        ch1: impl Unborrow<Target = impl Channel1Pin<T>> + 'd,
-        ch2: impl Unborrow<Target = impl Channel2Pin<T>> + 'd,
-        ch3: impl Unborrow<Target = impl Channel3Pin<T>> + 'd,
-        ch4: impl Unborrow<Target = impl Channel4Pin<T>> + 'd,
+        tim: impl Peripheral<P = T> + 'd,
+        ch1: impl Peripheral<P = impl Channel1Pin<T>> + 'd,
+        ch2: impl Peripheral<P = impl Channel2Pin<T>> + 'd,
+        ch3: impl Peripheral<P = impl Channel3Pin<T>> + 'd,
+        ch4: impl Peripheral<P = impl Channel4Pin<T>> + 'd,
         freq: Hertz,
     ) -> Self {
-        unborrow!(tim, ch1, ch2, ch3, ch4);
+        into_ref!(tim, ch1, ch2, ch3, ch4);
 
         T::enable();
         <T as embassy_stm32::rcc::low_level::RccPeripheral>::reset();
@@ -78,10 +75,7 @@ impl<'d, T: CaptureCompare32bitInstance> SimplePwm32<'d, T> {
             ch4.set_as_af(ch1.af_num(), AFType::OutputPushPull);
         }
 
-        let mut this = Self {
-            inner: tim,
-            phantom: PhantomData,
-        };
+        let mut this = Self { inner: tim };
 
         this.set_freq(freq);
         this.inner.start();
diff --git a/examples/stm32h7/src/bin/sdmmc.rs b/examples/stm32h7/src/bin/sdmmc.rs
index 787f700ae..163807d86 100644
--- a/examples/stm32h7/src/bin/sdmmc.rs
+++ b/examples/stm32h7/src/bin/sdmmc.rs
@@ -21,10 +21,15 @@ async fn main(_spawner: Spawner, p: Peripherals) -> ! {
 
     let irq = interrupt::take!(SDMMC1);
 
-    let mut sdmmc = Sdmmc::new(
+    let mut sdmmc = Sdmmc::new_4bit(
         p.SDMMC1,
-        (p.PC12, p.PD2, p.PC8, p.PC9, p.PC10, p.PC11),
         irq,
+        p.PC12,
+        p.PD2,
+        p.PC8,
+        p.PC9,
+        p.PC10,
+        p.PC11,
         Default::default(),
     );