nrf: replace PhantomData usages with PeripheralRef.

embassy-hal-common/src/peripheral.rs

@@ -27,6 +27,36 @@ impl<'a, T> PeripheralRef<'a, T> {
         }
     }
 
+    /// 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

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::{into_ref, low_power_wait_until};
+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};
@@ -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>,
@@ -78,7 +77,7 @@ 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 Peripheral<P = U> + '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,
@@ -91,7 +90,7 @@ impl<'d, U: UarteInstance, T: TimerInstance> BufferedUarte<'d, U, T> {
         rx_buffer: &'d mut [u8],
         tx_buffer: &'d mut [u8],
     ) -> Self {
-        into_ref!(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();
 
@@ -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,

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::impl_peripheral;
+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,
+    pin: PeripheralRef<'a, AnyPin>,
-    phantom: PhantomData<&'a mut 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) };
+        self.pin.conf().modify(|_, w| w.sense().disabled());
-        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 self.pin.conf().read().sense().is_disabled() {
-        if 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::new(&mut self.pin).await
-        PortInputFuture {
-            pin_port: self.pin.pin_port(),
-            phantom: PhantomData,
-        }
-        .await
     }
 
     pub async fn wait_for_low(&mut self) {
         self.pin.conf().modify(|_, w| w.sense().low());
-
+        PortInputFuture::new(&mut self.pin).await
-        PortInputFuture {
-            pin_port: self.pin.pin_port(),
-            phantom: PhantomData,
-        }
-        .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 {
+        PortInputFuture::new(&mut self.pin).await
-            pin_port: self.pin.pin_port(),
-            phantom: PhantomData,
-        }
-        .await
     }
 }
 

embassy-nrf/src/nvmc.rs

@@ -1,9 +1,8 @@
 //! Nvmcerature sensor interface.
 
-use core::marker::PhantomData;
 use core::{ptr, slice};
 
-use embassy_hal_common::into_ref;
+use embassy_hal_common::{into_ref, PeripheralRef};
 use embedded_storage::nor_flash::{
     ErrorType, MultiwriteNorFlash, NorFlash, NorFlashError, NorFlashErrorKind, ReadNorFlash,
 };
@@ -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 Peripheral<P = NVMC> + 'd) -> Self {
         into_ref!(_p);
-
+        Self { _p }
-        Self { _p: PhantomData }
     }
 
     fn regs() -> &'static pac::nvmc::RegisterBlock {

embassy-nrf/src/pwm.rs

@@ -1,6 +1,5 @@
 #![macro_use]
 
-use core::marker::PhantomData;
 use core::sync::atomic::{compiler_fence, Ordering};
 
 use embassy_hal_common::{into_ref, PeripheralRef};
@@ -15,7 +14,7 @@ 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<PeripheralRef<'d, AnyPin>>,
     ch1: Option<PeripheralRef<'d, AnyPin>>,
@@ -26,7 +25,7 @@ pub struct SimplePwm<'d, T: Instance> {
 /// 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>,
+    _peri: PeripheralRef<'d, T>,
     ch0: Option<PeripheralRef<'d, AnyPin>>,
     ch1: Option<PeripheralRef<'d, AnyPin>>,
     ch2: Option<PeripheralRef<'d, AnyPin>>,
@@ -120,6 +119,8 @@ impl<'d, T: Instance> SequencePwm<'d, T> {
         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,
@@ -639,6 +640,8 @@ impl<'d, T: Instance> SimplePwm<'d, T> {
         ch2: Option<PeripheralRef<'d, AnyPin>>,
         ch3: Option<PeripheralRef<'d, AnyPin>>,
     ) -> Self {
+        into_ref!(_pwm);
+
         let r = T::regs();
 
         if let Some(pin) = &ch0 {
@@ -666,7 +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,

embassy-nrf/src/qdec.rs

@@ -1,6 +1,5 @@
 //! Quadrature decoder interface
 
-use core::marker::PhantomData;
 use core::task::Poll;
 
 use embassy::waitqueue::AtomicWaker;
@@ -15,7 +14,7 @@ use crate::{interrupt, pac, Peripheral};
 
 /// Quadrature decoder
 pub struct Qdec<'d> {
-    phantom: PhantomData<&'d QDEC>,
+    _p: PeripheralRef<'d, QDEC>,
 }
 
 #[non_exhaustive]
@@ -66,14 +65,14 @@ impl<'d> Qdec<'d> {
     }
 
     fn new_inner(
-        _t: impl Peripheral<P = QDEC> + 'd,
+        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 {
-        into_ref!(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.

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::{impl_peripheral, into_ref};
+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};
@@ -14,6 +13,7 @@ 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};
@@ -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();
@@ -66,63 +66,11 @@ 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>,
+    n_channel: Option<PeripheralRef<'d, AnyInput>>,
-
-    phantom: PhantomData<&'d ()>,
 }
 
-/// A dummy `Input` pin implementation for SAADC peripheral sampling from the
-/// internal voltage.
-pub struct VddInput;
-
-impl_peripheral!(VddInput);
-
-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"))]
-impl_peripheral!(VddhDiv5Input);
-
-#[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,
-}
-
-impl_peripheral!(AnyInput);
-
-impl sealed::Input for AnyInput {
-    fn channel(&self) -> InputChannel {
-        self.channel
-    }
-}
-
-impl Input for AnyInput {}
-
 impl<'d> ChannelConfig<'d> {
     /// Default configuration for single ended channel sampling.
     pub fn single_ended(input: impl Peripheral<P = impl Input> + 'd) -> Self {
@@ -132,9 +80,8 @@ impl<'d> ChannelConfig<'d> {
             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.
@@ -148,9 +95,8 @@ impl<'d> ChannelConfig<'d> {
             gain: Gain::GAIN1_6,
             resistor: Resistor::BYPASS,
             time: Time::_10US,
-            p_channel: p_input.channel(),
+            p_channel: p_input.map_into(),
-            n_channel: Some(n_input.channel()),
+            n_channel: Some(n_input.map_into()),
-            phantom: PhantomData,
         }
     }
 }
@@ -167,12 +113,12 @@ pub enum SamplerState {
 
 impl<'d, const N: usize> Saadc<'d, N> {
     pub fn new(
-        _saadc: impl Peripheral<P = peripherals::SAADC> + 'd,
+        saadc: impl Peripheral<P = peripherals::SAADC> + 'd,
         irq: impl Peripheral<P = interrupt::SAADC> + 'd,
         config: Config,
         channel_configs: [ChannelConfig; N],
     ) -> Self {
-        into_ref!(irq);
+        into_ref!(saadc, irq);
 
         let r = unsafe { &*SAADC::ptr() };
 
@@ -184,9 +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));
+            r.ch[i].pselp.write(|w| w.pselp().variant(cc.p_channel.channel()));
-            if let Some(n_channel) = cc.n_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]
+                    .pseln
+                    .write(|w| unsafe { w.pseln().bits(n_channel.channel() as u8) });
             }
             r.ch[i].config.write(|w| {
                 w.refsel().variant(cc.reference.into());
@@ -215,7 +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 ()) {
@@ -674,7 +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 + Peripheral<P = Self> + Sized {
+pub trait Input: sealed::Input + Into<AnyInput> + Peripheral<P = Self> + Sized + 'static {
     fn degrade_saadc(self) -> AnyInput {
         AnyInput {
             channel: self.channel(),
@@ -682,13 +630,57 @@ pub trait Input: sealed::Input + Peripheral<P = 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);

embassy-nrf/src/spim.rs

@@ -1,6 +1,5 @@
 #![macro_use]
 
-use core::marker::PhantomData;
 use core::sync::atomic::{compiler_fence, Ordering};
 use core::task::Poll;
 
@@ -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]
@@ -94,14 +93,14 @@ impl<'d, T: Instance> Spim<'d, T> {
     }
 
     fn new_inner(
-        _spim: impl Peripheral<P = T> + 'd,
+        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 {
-        into_ref!(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 ()) {

embassy-nrf/src/timer.rs

@@ -5,7 +5,7 @@ use core::task::Poll;
 
 use embassy::waitqueue::AtomicWaker;
 use embassy_hal_common::drop::OnDrop;
-use embassy_hal_common::into_ref;
+use embassy_hal_common::{into_ref, PeripheralRef};
 use futures::future::poll_fn;
 
 use crate::interrupt::{Interrupt, InterruptExt};
@@ -95,7 +95,8 @@ 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> {
@@ -123,10 +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 Peripheral<P = 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.
@@ -230,7 +236,8 @@ impl<'d, T: Instance, I: TimerType> Timer<'d, T, I> {
         }
         Cc {
             n,
-            phantom: PhantomData,
+            _p: self._p.reborrow(),
+            _i: PhantomData,
         }
     }
 }
@@ -242,12 +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`.
@@ -281,9 +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()

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;
@@ -16,7 +15,7 @@ use core::task::Poll;
 use embassy::time::{Duration, Instant};
 use embassy::waitqueue::AtomicWaker;
 use embassy_embedded_hal::SetConfig;
-use embassy_hal_common::into_ref;
+use embassy_hal_common::{into_ref, PeripheralRef};
 use futures::future::poll_fn;
 
 use crate::chip::{EASY_DMA_SIZE, FORCE_COPY_BUFFER_SIZE};
@@ -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 Peripheral<P = T> + '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 {
-        into_ref!(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 ()) {

embassy-nrf/src/uarte.rs

@@ -13,7 +13,6 @@
 //! 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;
 
@@ -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>,
 }
@@ -71,13 +69,13 @@ 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> {
@@ -116,7 +114,7 @@ impl<'d, T: Instance> Uarte<'d, T> {
     }
 
     fn new_inner(
-        _uarte: impl Peripheral<P = T> + 'd,
+        uarte: impl Peripheral<P = T> + 'd,
         irq: impl Peripheral<P = T::Interrupt> + 'd,
         rxd: PeripheralRef<'d, AnyPin>,
         txd: PeripheralRef<'d, AnyPin>,
@@ -124,7 +122,7 @@ impl<'d, T: Instance> Uarte<'d, T> {
         rts: Option<PeripheralRef<'d, AnyPin>>,
         config: Config,
     ) -> Self {
-        into_ref!(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 {
-            tx: UarteTx { phantom: PhantomData },
+                _p: unsafe { uarte.clone_unchecked() },
-            rx: UarteRx { phantom: PhantomData },
+            },
+            rx: UarteRx { _p: uarte },
         }
     }
 
@@ -267,13 +266,13 @@ impl<'d, T: Instance> UarteTx<'d, T> {
     }
 
     fn new_inner(
-        _uarte: impl Peripheral<P = T> + 'd,
+        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 {
-        into_ref!(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> {
@@ -459,13 +458,13 @@ impl<'d, T: Instance> UarteRx<'d, T> {
     }
 
     fn new_inner(
-        _uarte: impl Peripheral<P = T> + 'd,
+        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 {
-        into_ref!(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> {

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::into_ref;
+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};
@@ -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,
@@ -166,14 +166,14 @@ impl UsbSupply for SignalledSupply {
 }
 
 impl<'d, T: Instance, P: UsbSupply> Driver<'d, T, P> {
-    pub fn new(_usb: impl Peripheral<P = T> + 'd, irq: impl Peripheral<P = T::Interrupt> + 'd, usb_supply: P) -> Self {
+    pub fn new(usb: impl Peripheral<P = T> + 'd, irq: impl Peripheral<P = T::Interrupt> + 'd, usb_supply: P) -> Self {
-        into_ref!(irq);
+        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,
@@ -269,15 +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,
             },
         )
@@ -285,7 +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,
 }
@@ -746,7 +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,
 }