Merge pull request #2649 from blueluna/feat/radio-ieee802154

[embassy-nrf] IEEE 802.15.4 radio

13 files changed, 650 insertions, 51 deletions

diff --git a/embassy-nrf/src/chips/nrf51.rs b/embassy-nrf/src/chips/nrf51.rs
index 016352fb8..cc1cbc8a0 100644
--- a/embassy-nrf/src/chips/nrf51.rs
+++ b/embassy-nrf/src/chips/nrf51.rs
@@ -99,6 +99,9 @@ embassy_hal_internal::peripherals! {
 
     // TEMP
     TEMP,
+
+    // Radio
+    RADIO,
 }
 
 impl_timer!(TIMER0, TIMER0, TIMER0);
@@ -140,6 +143,8 @@ impl_pin!(P0_29, 0, 29);
 impl_pin!(P0_30, 0, 30);
 impl_pin!(P0_31, 0, 31);
 
+impl_radio!(RADIO, RADIO, RADIO);
+
 embassy_hal_internal::interrupt_mod!(
     POWER_CLOCK,
     RADIO,
diff --git a/embassy-nrf/src/chips/nrf52805.rs b/embassy-nrf/src/chips/nrf52805.rs
index 624d6613d..14c3f9b1a 100644
--- a/embassy-nrf/src/chips/nrf52805.rs
+++ b/embassy-nrf/src/chips/nrf52805.rs
@@ -129,6 +129,9 @@ embassy_hal_internal::peripherals! {
 
     // QDEC
     QDEC,
+
+    // Radio
+    RADIO,
 }
 
 impl_uarte!(UARTE0, UARTE0, UARTE0_UART0);
@@ -209,6 +212,8 @@ impl_ppi_channel!(PPI_CH31, 31 => static);
 impl_saadc_input!(P0_04, ANALOG_INPUT2);
 impl_saadc_input!(P0_05, ANALOG_INPUT3);
 
+impl_radio!(RADIO, RADIO, RADIO);
+
 embassy_hal_internal::interrupt_mod!(
     POWER_CLOCK,
     RADIO,
diff --git a/embassy-nrf/src/chips/nrf52810.rs b/embassy-nrf/src/chips/nrf52810.rs
index 002feab3b..c607586db 100644
--- a/embassy-nrf/src/chips/nrf52810.rs
+++ b/embassy-nrf/src/chips/nrf52810.rs
@@ -135,6 +135,9 @@ embassy_hal_internal::peripherals! {
 
     // PDM
     PDM,
+
+    // Radio
+    RADIO,
 }
 
 impl_uarte!(UARTE0, UARTE0, UARTE0_UART0);
@@ -235,6 +238,8 @@ impl_saadc_input!(P0_29, ANALOG_INPUT5);
 impl_saadc_input!(P0_30, ANALOG_INPUT6);
 impl_saadc_input!(P0_31, ANALOG_INPUT7);
 
+impl_radio!(RADIO, RADIO, RADIO);
+
 embassy_hal_internal::interrupt_mod!(
     POWER_CLOCK,
     RADIO,
diff --git a/embassy-nrf/src/chips/nrf52811.rs b/embassy-nrf/src/chips/nrf52811.rs
index 5952907f8..5f70365b4 100644
--- a/embassy-nrf/src/chips/nrf52811.rs
+++ b/embassy-nrf/src/chips/nrf52811.rs
@@ -135,6 +135,9 @@ embassy_hal_internal::peripherals! {
 
     // PDM
     PDM,
+
+    // Radio
+    RADIO,
 }
 
 impl_uarte!(UARTE0, UARTE0, UARTE0_UART0);
@@ -237,6 +240,8 @@ impl_saadc_input!(P0_29, ANALOG_INPUT5);
 impl_saadc_input!(P0_30, ANALOG_INPUT6);
 impl_saadc_input!(P0_31, ANALOG_INPUT7);
 
+impl_radio!(RADIO, RADIO, RADIO);
+
 embassy_hal_internal::interrupt_mod!(
     POWER_CLOCK,
     RADIO,
diff --git a/embassy-nrf/src/chips/nrf52820.rs b/embassy-nrf/src/chips/nrf52820.rs
index c2f792cb9..82d097407 100644
--- a/embassy-nrf/src/chips/nrf52820.rs
+++ b/embassy-nrf/src/chips/nrf52820.rs
@@ -130,6 +130,9 @@ embassy_hal_internal::peripherals! {
 
     // QDEC
     QDEC,
+
+    // Radio
+    RADIO,
 }
 
 impl_usb!(USBD, USBD, USBD);
@@ -224,6 +227,8 @@ impl_ppi_channel!(PPI_CH29, 29 => static);
 impl_ppi_channel!(PPI_CH30, 30 => static);
 impl_ppi_channel!(PPI_CH31, 31 => static);
 
+impl_radio!(RADIO, RADIO, RADIO);
+
 embassy_hal_internal::interrupt_mod!(
     POWER_CLOCK,
     RADIO,
diff --git a/embassy-nrf/src/chips/nrf52832.rs b/embassy-nrf/src/chips/nrf52832.rs
index 65d52364d..67b32fe5f 100644
--- a/embassy-nrf/src/chips/nrf52832.rs
+++ b/embassy-nrf/src/chips/nrf52832.rs
@@ -150,6 +150,9 @@ embassy_hal_internal::peripherals! {
 
     // PDM
     PDM,
+
+    // Radio
+    RADIO,
 }
 
 impl_uarte!(UARTE0, UARTE0, UARTE0_UART0);
@@ -264,6 +267,8 @@ impl_saadc_input!(P0_31, ANALOG_INPUT7);
 
 impl_i2s!(I2S, I2S, I2S);
 
+impl_radio!(RADIO, RADIO, RADIO);
+
 embassy_hal_internal::interrupt_mod!(
     POWER_CLOCK,
     RADIO,
diff --git a/embassy-nrf/src/chips/nrf52833.rs b/embassy-nrf/src/chips/nrf52833.rs
index 7c9b66d69..20f14e2d6 100644
--- a/embassy-nrf/src/chips/nrf52833.rs
+++ b/embassy-nrf/src/chips/nrf52833.rs
@@ -170,6 +170,9 @@ embassy_hal_internal::peripherals! {
 
     // I2S
     I2S,
+
+    // Radio
+    RADIO,
 }
 
 impl_usb!(USBD, USBD, USBD);
@@ -306,6 +309,8 @@ impl_saadc_input!(P0_31, ANALOG_INPUT7);
 
 impl_i2s!(I2S, I2S, I2S);
 
+impl_radio!(RADIO, RADIO, RADIO);
+
 embassy_hal_internal::interrupt_mod!(
     POWER_CLOCK,
     RADIO,
diff --git a/embassy-nrf/src/chips/nrf5340_net.rs b/embassy-nrf/src/chips/nrf5340_net.rs
index a7cf82872..65e8f9653 100644
--- a/embassy-nrf/src/chips/nrf5340_net.rs
+++ b/embassy-nrf/src/chips/nrf5340_net.rs
@@ -248,6 +248,9 @@ embassy_hal_internal::peripherals! {
     P1_13,
     P1_14,
     P1_15,
+
+    // Radio
+    RADIO,
 }
 
 impl_uarte!(SERIAL0, UARTE0, SERIAL0);
@@ -345,6 +348,8 @@ impl_ppi_channel!(PPI_CH29, 29 => configurable);
 impl_ppi_channel!(PPI_CH30, 30 => configurable);
 impl_ppi_channel!(PPI_CH31, 31 => configurable);
 
+impl_radio!(RADIO, RADIO, RADIO);
+
 embassy_hal_internal::interrupt_mod!(
     CLOCK_POWER,
     RADIO,
diff --git a/embassy-nrf/src/lib.rs b/embassy-nrf/src/lib.rs
index 04a6293a4..718f229a3 100644
--- a/embassy-nrf/src/lib.rs
+++ b/embassy-nrf/src/lib.rs
@@ -47,7 +47,7 @@ pub mod gpio;
 pub mod gpiote;
 
 // TODO: tested on other chips
-#[cfg(any(feature = "nrf52840"))]
+#[cfg(not(any(feature = "_nrf9160", feature = "_nrf5340-app")))]
 pub mod radio;
 
 #[cfg(any(feature = "nrf52832", feature = "nrf52833", feature = "nrf52840"))]
diff --git a/embassy-nrf/src/radio/ble.rs b/embassy-nrf/src/radio/ble.rs
index 24dba582f..93003fb19 100644
--- a/embassy-nrf/src/radio/ble.rs
+++ b/embassy-nrf/src/radio/ble.rs
@@ -7,27 +7,14 @@ use core::task::Poll;
 use embassy_hal_internal::drop::OnDrop;
 use embassy_hal_internal::{into_ref, PeripheralRef};
 pub use pac::radio::mode::MODE_A as Mode;
+#[cfg(not(feature = "nrf51"))]
 use pac::radio::pcnf0::PLEN_A as PreambleLength;
-use pac::radio::state::STATE_A as RadioState;
-pub use pac::radio::txpower::TXPOWER_A as TxPower;
 
 use crate::interrupt::typelevel::Interrupt;
 use crate::radio::*;
+pub use crate::radio::{Error, TxPower};
 use crate::util::slice_in_ram_or;
 
-/// RADIO error.
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-#[cfg_attr(feature = "defmt", derive(defmt::Format))]
-#[non_exhaustive]
-pub enum Error {
-    /// Buffer was too long.
-    BufferTooLong,
-    /// Buffer was to short.
-    BufferTooShort,
-    /// The buffer is not in data RAM. It is most likely in flash, and nRF's DMA cannot access flash.
-    BufferNotInRAM,
-}
-
 /// Radio driver.
 pub struct Radio<'d, T: Instance> {
     _p: PeripheralRef<'d, T>,
@@ -98,6 +85,7 @@ impl<'d, T: Instance> Radio<'d, T> {
 
         // Ch map between 2400 MHZ .. 2500 MHz
         // All modes use this range
+        #[cfg(not(feature = "nrf51"))]
         r.frequency.write(|w| w.map().default());
 
         // Configure shortcuts to simplify and speed up sending and receiving packets.
@@ -115,25 +103,7 @@ impl<'d, T: Instance> Radio<'d, T> {
     }
 
     fn state(&self) -> RadioState {
-        match T::regs().state.read().state().variant() {
-            Some(s) => s,
-            None => unreachable!(),
-        }
-    }
-
-    #[allow(dead_code)]
-    fn trace_state(&self) {
-        match self.state() {
-            RadioState::DISABLED => trace!("radio:state:DISABLED"),
-            RadioState::RX_RU => trace!("radio:state:RX_RU"),
-            RadioState::RX_IDLE => trace!("radio:state:RX_IDLE"),
-            RadioState::RX => trace!("radio:state:RX"),
-            RadioState::RX_DISABLE => trace!("radio:state:RX_DISABLE"),
-            RadioState::TX_RU => trace!("radio:state:TX_RU"),
-            RadioState::TX_IDLE => trace!("radio:state:TX_IDLE"),
-            RadioState::TX => trace!("radio:state:TX"),
-            RadioState::TX_DISABLE => trace!("radio:state:TX_DISABLE"),
-        }
+        super::state(T::regs())
     }
 
     /// Set the radio mode
@@ -145,10 +115,18 @@ impl<'d, T: Instance> Radio<'d, T> {
         let r = T::regs();
         r.mode.write(|w| w.mode().variant(mode));
 
+        #[cfg(not(feature = "nrf51"))]
         r.pcnf0.write(|w| {
             w.plen().variant(match mode {
                 Mode::BLE_1MBIT => PreambleLength::_8BIT,
                 Mode::BLE_2MBIT => PreambleLength::_16BIT,
+                #[cfg(any(
+                    feature = "nrf52811",
+                    feature = "nrf52820",
+                    feature = "nrf52833",
+                    feature = "nrf52840",
+                    feature = "_nrf5340-net"
+                ))]
                 Mode::BLE_LR125KBIT | Mode::BLE_LR500KBIT => PreambleLength::LONG_RANGE,
                 _ => unimplemented!(),
             })
@@ -331,7 +309,8 @@ impl<'d, T: Instance> Radio<'d, T> {
         self.trigger_and_wait_end(move || {
             // Initialize the transmission
             // trace!("txen");
-            r.tasks_txen.write(|w| w.tasks_txen().set_bit());
+
+            r.tasks_txen.write(|w| unsafe { w.bits(1) });
         })
         .await;
 
@@ -348,7 +327,7 @@ impl<'d, T: Instance> Radio<'d, T> {
         self.trigger_and_wait_end(move || {
             // Initialize the transmission
             // trace!("rxen");
-            r.tasks_rxen.write(|w| w.tasks_rxen().set_bit());
+            r.tasks_rxen.write(|w| unsafe { w.bits(1) });
         })
         .await;
 
@@ -370,10 +349,10 @@ impl<'d, T: Instance> Radio<'d, T> {
             r.intenclr.write(|w| w.end().clear());
             r.events_end.reset();
 
-            r.tasks_stop.write(|w| w.tasks_stop().set_bit());
+            r.tasks_stop.write(|w| unsafe { w.bits(1) });
 
             // The docs don't explicitly mention any event to acknowledge the stop task
-            while r.events_end.read().events_end().bit_is_clear() {}
+            while r.events_end.read().bits() == 0 {}
 
             trace!("radio drop: stopped");
         });
@@ -393,8 +372,8 @@ impl<'d, T: Instance> Radio<'d, T> {
 
         // On poll check if interrupt happen
         poll_fn(|cx| {
-            s.end_waker.register(cx.waker());
-            if r.events_end.read().events_end().bit_is_set() {
+            s.event_waker.register(cx.waker());
+            if r.events_end.read().bits() == 1 {
                 // trace!("radio:end");
                 return core::task::Poll::Ready(());
             }
@@ -418,10 +397,10 @@ impl<'d, T: Instance> Radio<'d, T> {
         if self.state() != RadioState::DISABLED {
             trace!("radio:disable");
             // Trigger the disable task
-            r.tasks_disable.write(|w| w.tasks_disable().set_bit());
+            r.tasks_disable.write(|w| unsafe { w.bits(1) });
 
             // Wait until the radio is disabled
-            while r.events_disabled.read().events_disabled().bit_is_clear() {}
+            while r.events_disabled.read().bits() == 0 {}
 
             compiler_fence(Ordering::SeqCst);
 
diff --git a/embassy-nrf/src/radio/ieee802154.rs b/embassy-nrf/src/radio/ieee802154.rs
new file mode 100644
index 000000000..298f8a574
--- /dev/null
+++ b/embassy-nrf/src/radio/ieee802154.rs
@@ -0,0 +1,546 @@
+//! IEEE 802.15.4 radio driver
+
+use core::sync::atomic::{compiler_fence, Ordering};
+use core::task::Poll;
+
+use embassy_hal_internal::drop::OnDrop;
+use embassy_hal_internal::{into_ref, PeripheralRef};
+
+use super::{state, Error, Instance, InterruptHandler, RadioState, TxPower};
+use crate::interrupt::typelevel::Interrupt;
+use crate::interrupt::{self};
+use crate::Peripheral;
+
+/// Default (IEEE compliant) Start of Frame Delimiter
+pub const DEFAULT_SFD: u8 = 0xA7;
+
+// TODO expose the other variants in `pac::CCAMODE_A`
+/// Clear Channel Assessment method
+pub enum Cca {
+    /// Carrier sense
+    CarrierSense,
+    /// Energy Detection / Energy Above Threshold
+    EnergyDetection {
+        /// Energy measurements above this value mean that the channel is assumed to be busy.
+        /// Note the measurement range is 0..0xFF - where 0 means that the received power was
+        /// less than 10 dB above the selected receiver sensitivity. This value is not given in dBm,
+        /// but can be converted. See the nrf52840 Product Specification Section 6.20.12.4
+        /// for details.
+        ed_threshold: u8,
+    },
+}
+
+/// IEEE 802.15.4 radio driver.
+pub struct Radio<'d, T: Instance> {
+    _p: PeripheralRef<'d, T>,
+    needs_enable: bool,
+}
+
+impl<'d, T: Instance> Radio<'d, T> {
+    /// Create a new IEEE 802.15.4 radio driver.
+    pub fn new(
+        radio: impl Peripheral<P = T> + 'd,
+        _irq: impl interrupt::typelevel::Binding<T::Interrupt, InterruptHandler<T>> + 'd,
+    ) -> Self {
+        into_ref!(radio);
+
+        let r = T::regs();
+
+        // Disable and enable to reset peripheral
+        r.power.write(|w| w.power().disabled());
+        r.power.write(|w| w.power().enabled());
+
+        // Enable 802.15.4 mode
+        r.mode.write(|w| w.mode().ieee802154_250kbit());
+        // Configure CRC skip address
+        r.crccnf.write(|w| w.len().two().skipaddr().ieee802154());
+        unsafe {
+            // Configure CRC polynomial and init
+            r.crcpoly.write(|w| w.crcpoly().bits(0x0001_1021));
+            r.crcinit.write(|w| w.crcinit().bits(0));
+            r.pcnf0.write(|w| {
+                // 8-bit on air length
+                w.lflen()
+                    .bits(8)
+                    // Zero bytes S0 field length
+                    .s0len()
+                    .clear_bit()
+                    // Zero bytes S1 field length
+                    .s1len()
+                    .bits(0)
+                    // Do not include S1 field in RAM if S1 length > 0
+                    .s1incl()
+                    .clear_bit()
+                    // Zero code Indicator length
+                    .cilen()
+                    .bits(0)
+                    // 32-bit zero preamble
+                    .plen()
+                    ._32bit_zero()
+                    // Include CRC in length
+                    .crcinc()
+                    .include()
+            });
+            r.pcnf1.write(|w| {
+                // Maximum packet length
+                w.maxlen()
+                    .bits(Packet::MAX_PSDU_LEN)
+                    // Zero static length
+                    .statlen()
+                    .bits(0)
+                    // Zero base address length
+                    .balen()
+                    .bits(0)
+                    // Little-endian
+                    .endian()
+                    .clear_bit()
+                    // Disable packet whitening
+                    .whiteen()
+                    .clear_bit()
+            });
+        }
+
+        // Enable NVIC interrupt
+        T::Interrupt::unpend();
+        unsafe { T::Interrupt::enable() };
+
+        let mut radio = Self {
+            _p: radio,
+            needs_enable: false,
+        };
+
+        radio.set_sfd(DEFAULT_SFD);
+        radio.set_transmission_power(0);
+        radio.set_channel(11);
+        radio.set_cca(Cca::CarrierSense);
+
+        radio
+    }
+
+    /// Changes the radio channel
+    pub fn set_channel(&mut self, channel: u8) {
+        let r = T::regs();
+        if channel < 11 || channel > 26 {
+            panic!("Bad 802.15.4 channel");
+        }
+        let frequency_offset = (channel - 10) * 5;
+        self.needs_enable = true;
+        r.frequency
+            .write(|w| unsafe { w.frequency().bits(frequency_offset).map().default() });
+    }
+
+    /// Changes the Clear Channel Assessment method
+    pub fn set_cca(&mut self, cca: Cca) {
+        let r = T::regs();
+        self.needs_enable = true;
+        match cca {
+            Cca::CarrierSense => r.ccactrl.write(|w| w.ccamode().carrier_mode()),
+            Cca::EnergyDetection { ed_threshold } => {
+                // "[ED] is enabled by first configuring the field CCAMODE=EdMode in CCACTRL
+                // and writing the CCAEDTHRES field to a chosen value."
+                r.ccactrl
+                    .write(|w| unsafe { w.ccamode().ed_mode().ccaedthres().bits(ed_threshold) });
+            }
+        }
+    }
+
+    /// Changes the Start of Frame Delimiter (SFD)
+    pub fn set_sfd(&mut self, sfd: u8) {
+        let r = T::regs();
+        r.sfd.write(|w| unsafe { w.sfd().bits(sfd) });
+    }
+
+    /// Clear interrupts
+    pub fn clear_all_interrupts(&mut self) {
+        let r = T::regs();
+        r.intenclr.write(|w| unsafe { w.bits(0xffff_ffff) });
+    }
+
+    /// Changes the radio transmission power
+    pub fn set_transmission_power(&mut self, power: i8) {
+        let r = T::regs();
+        self.needs_enable = true;
+
+        let tx_power: TxPower = match power {
+            #[cfg(not(any(feature = "nrf52811", feature = "_nrf5340-net")))]
+            8 => TxPower::POS8D_BM,
+            #[cfg(not(any(feature = "nrf52811", feature = "_nrf5340-net")))]
+            7 => TxPower::POS7D_BM,
+            #[cfg(not(any(feature = "nrf52811", feature = "_nrf5340-net")))]
+            6 => TxPower::POS6D_BM,
+            #[cfg(not(any(feature = "nrf52811", feature = "_nrf5340-net")))]
+            5 => TxPower::POS5D_BM,
+            #[cfg(not(feature = "_nrf5340-net"))]
+            4 => TxPower::POS4D_BM,
+            #[cfg(not(feature = "_nrf5340-net"))]
+            3 => TxPower::POS3D_BM,
+            #[cfg(not(any(feature = "nrf52811", feature = "_nrf5340-net")))]
+            2 => TxPower::POS2D_BM,
+            0 => TxPower::_0D_BM,
+            #[cfg(feature = "_nrf5340-net")]
+            -1 => TxPower::NEG1D_BM,
+            #[cfg(feature = "_nrf5340-net")]
+            -2 => TxPower::NEG2D_BM,
+            #[cfg(feature = "_nrf5340-net")]
+            -3 => TxPower::NEG3D_BM,
+            -4 => TxPower::NEG4D_BM,
+            #[cfg(feature = "_nrf5340-net")]
+            -5 => TxPower::NEG5D_BM,
+            #[cfg(feature = "_nrf5340-net")]
+            -6 => TxPower::NEG6D_BM,
+            #[cfg(feature = "_nrf5340-net")]
+            -7 => TxPower::NEG7D_BM,
+            -8 => TxPower::NEG8D_BM,
+            -12 => TxPower::NEG12D_BM,
+            -16 => TxPower::NEG16D_BM,
+            -20 => TxPower::NEG20D_BM,
+            -30 => TxPower::NEG30D_BM,
+            -40 => TxPower::NEG40D_BM,
+            _ => panic!("Invalid transmission power value"),
+        };
+
+        r.txpower.write(|w| w.txpower().variant(tx_power));
+    }
+
+    /// Waits until the radio state matches the given `state`
+    fn wait_for_radio_state(&self, state: RadioState) {
+        while self.state() != state {}
+    }
+
+    /// Get the current radio state
+    fn state(&self) -> RadioState {
+        state(T::regs())
+    }
+
+    /// Moves the radio from any state to the DISABLED state
+    fn disable(&mut self) {
+        let r = T::regs();
+        // See figure 110 in nRF52840-PS
+        loop {
+            match self.state() {
+                RadioState::DISABLED => return,
+                // idle or ramping up
+                RadioState::RX_RU | RadioState::RX_IDLE | RadioState::TX_RU | RadioState::TX_IDLE => {
+                    r.tasks_disable.write(|w| w.tasks_disable().set_bit());
+                    self.wait_for_radio_state(RadioState::DISABLED);
+                    return;
+                }
+                // ramping down
+                RadioState::RX_DISABLE | RadioState::TX_DISABLE => {
+                    self.wait_for_radio_state(RadioState::DISABLED);
+                    return;
+                }
+                // cancel ongoing transfer or ongoing CCA
+                RadioState::RX => {
+                    r.tasks_ccastop.write(|w| w.tasks_ccastop().set_bit());
+                    r.tasks_stop.write(|w| w.tasks_stop().set_bit());
+                    self.wait_for_radio_state(RadioState::RX_IDLE);
+                }
+                RadioState::TX => {
+                    r.tasks_stop.write(|w| w.tasks_stop().set_bit());
+                    self.wait_for_radio_state(RadioState::TX_IDLE);
+                }
+            }
+        }
+    }
+
+    fn set_buffer(&mut self, buffer: &[u8]) {
+        let r = T::regs();
+        r.packetptr.write(|w| unsafe { w.bits(buffer.as_ptr() as u32) });
+    }
+
+    /// Moves the radio to the RXIDLE state
+    fn receive_prepare(&mut self) {
+        // clear related events
+        T::regs().events_ccabusy.reset();
+        T::regs().events_phyend.reset();
+        // NOTE to avoid errata 204 (see rev1 v1.4) we do TX_IDLE -> DISABLED -> RX_IDLE
+        let disable = match self.state() {
+            RadioState::DISABLED => false,
+            RadioState::RX_IDLE => self.needs_enable,
+            _ => true,
+        };
+        if disable {
+            self.disable();
+        }
+        self.needs_enable = false;
+    }
+
+    /// Prepare radio for receiving a packet
+    fn receive_start(&mut self, packet: &mut Packet) {
+        // NOTE we do NOT check the address of `packet` because the mutable reference ensures it's
+        // allocated in RAM
+        let r = T::regs();
+
+        self.receive_prepare();
+
+        // Configure shortcuts
+        //
+        // The radio goes through following states when receiving a 802.15.4 packet
+        //
+        // enable RX → ramp up RX → RX idle → Receive → end (PHYEND)
+        r.shorts.write(|w| w.rxready_start().enabled());
+
+        // set up RX buffer
+        self.set_buffer(packet.buffer.as_mut());
+
+        // start transfer
+        dma_start_fence();
+
+        match self.state() {
+            // Re-start receiver
+            RadioState::RX_IDLE => r.tasks_start.write(|w| w.tasks_start().set_bit()),
+            // Enable receiver
+            _ => r.tasks_rxen.write(|w| w.tasks_rxen().set_bit()),
+        }
+    }
+
+    /// Cancel receiving packet
+    fn receive_cancel() {
+        let r = T::regs();
+        r.shorts.reset();
+        r.tasks_stop.write(|w| w.tasks_stop().set_bit());
+        loop {
+            match state(r) {
+                RadioState::DISABLED | RadioState::RX_IDLE => break,
+                _ => (),
+            }
+        }
+        // DMA transfer may have been in progress so synchronize with its memory operations
+        dma_end_fence();
+    }
+
+    /// Receives one radio packet and copies its contents into the given `packet` buffer
+    ///
+    /// This methods returns the `Ok` variant if the CRC included the packet was successfully
+    /// validated by the hardware; otherwise it returns the `Err` variant. In either case, `packet`
+    /// will be updated with the received packet's data
+    pub async fn receive(&mut self, packet: &mut Packet) -> Result<(), Error> {
+        let s = T::state();
+        let r = T::regs();
+
+        // Start the read
+        self.receive_start(packet);
+
+        let dropper = OnDrop::new(|| Self::receive_cancel());
+
+        self.clear_all_interrupts();
+        // wait until we have received something
+        core::future::poll_fn(|cx| {
+            s.event_waker.register(cx.waker());
+
+            if r.events_phyend.read().events_phyend().bit_is_set() {
+                r.events_phyend.reset();
+                trace!("RX done poll");
+                return Poll::Ready(());
+            } else {
+                r.intenset.write(|w| w.phyend().set());
+            };
+
+            Poll::Pending
+        })
+        .await;
+
+        dma_end_fence();
+        dropper.defuse();
+
+        let crc = r.rxcrc.read().rxcrc().bits() as u16;
+        if r.crcstatus.read().crcstatus().bit_is_set() {
+            Ok(())
+        } else {
+            Err(Error::CrcFailed(crc))
+        }
+    }
+
+    /// Tries to send the given `packet`
+    ///
+    /// This method performs Clear Channel Assessment (CCA) first and sends the `packet` only if the
+    /// channel is observed to be *clear* (no transmission is currently ongoing), otherwise no
+    /// packet is transmitted and the `Err` variant is returned
+    ///
+    /// NOTE this method will *not* modify the `packet` argument. The mutable reference is used to
+    /// ensure the `packet` buffer is allocated in RAM, which is required by the RADIO peripheral
+    // NOTE we do NOT check the address of `packet` because the mutable reference ensures it's
+    // allocated in RAM
+    pub async fn try_send(&mut self, packet: &mut Packet) -> Result<(), Error> {
+        let s = T::state();
+        let r = T::regs();
+
+        // enable radio to perform cca
+        self.receive_prepare();
+
+        /// transmit result
+        #[derive(Debug, Clone, Copy, PartialEq, Eq)]
+        #[cfg_attr(feature = "defmt", derive(defmt::Format))]
+        pub enum TransmitResult {
+            /// Success
+            Success,
+            /// Clear channel assessment reported channel in use
+            ChannelInUse,
+        }
+
+        // Configure shortcuts
+        //
+        // The radio goes through following states when sending a 802.15.4 packet
+        //
+        // enable RX → ramp up RX → clear channel assessment (CCA) → CCA result
+        // CCA idle → enable TX → start TX → TX → end (PHYEND) → disabled
+        //
+        // CCA might end up in the event CCABUSY in which there will be no transmission
+        r.shorts.write(|w| {
+            w.rxready_ccastart()
+                .enabled()
+                .ccaidle_txen()
+                .enabled()
+                .txready_start()
+                .enabled()
+                .ccabusy_disable()
+                .enabled()
+                .phyend_disable()
+                .enabled()
+        });
+
+        // Set transmission buffer
+        self.set_buffer(packet.buffer.as_mut());
+
+        // the DMA transfer will start at some point after the following write operation so
+        // we place the compiler fence here
+        dma_start_fence();
+        // start CCA. In case the channel is clear, the data at packetptr will be sent automatically
+
+        match self.state() {
+            // Re-start receiver
+            RadioState::RX_IDLE => r.tasks_ccastart.write(|w| w.tasks_ccastart().set_bit()),
+            // Enable receiver
+            _ => r.tasks_rxen.write(|w| w.tasks_rxen().set_bit()),
+        }
+
+        self.clear_all_interrupts();
+        let result = core::future::poll_fn(|cx| {
+            s.event_waker.register(cx.waker());
+
+            if r.events_phyend.read().events_phyend().bit_is_set() {
+                r.events_phyend.reset();
+                r.events_ccabusy.reset();
+                trace!("TX done poll");
+                return Poll::Ready(TransmitResult::Success);
+            } else if r.events_ccabusy.read().events_ccabusy().bit_is_set() {
+                r.events_ccabusy.reset();
+                trace!("TX no CCA");
+                return Poll::Ready(TransmitResult::ChannelInUse);
+            }
+
+            r.intenset.write(|w| w.phyend().set().ccabusy().set());
+
+            Poll::Pending
+        })
+        .await;
+
+        match result {
+            TransmitResult::Success => Ok(()),
+            TransmitResult::ChannelInUse => Err(Error::ChannelInUse),
+        }
+    }
+}
+
+/// An IEEE 802.15.4 packet
+///
+/// This `Packet` is a PHY layer packet. It's made up of the physical header (PHR) and the PSDU
+/// (PHY service data unit). The PSDU of this `Packet` will always include the MAC level CRC, AKA
+/// the FCS (Frame Control Sequence) -- the CRC is fully computed in hardware and automatically
+/// appended on transmission and verified on reception.
+///
+/// The API lets users modify the usable part (not the CRC) of the PSDU via the `deref` and
+/// `copy_from_slice` methods. These methods will automatically update the PHR.
+///
+/// See figure 119 in the Product Specification of the nRF52840 for more details
+pub struct Packet {
+    buffer: [u8; Self::SIZE],
+}
+
+// See figure 124 in nRF52840-PS
+impl Packet {
+    // for indexing purposes
+    const PHY_HDR: usize = 0;
+    const DATA: core::ops::RangeFrom<usize> = 1..;
+
+    /// Maximum amount of usable payload (CRC excluded) a single packet can contain, in bytes
+    pub const CAPACITY: u8 = 125;
+    const CRC: u8 = 2; // size of the CRC, which is *never* copied to / from RAM
+    const MAX_PSDU_LEN: u8 = Self::CAPACITY + Self::CRC;
+    const SIZE: usize = 1 /* PHR */ + Self::MAX_PSDU_LEN as usize;
+
+    /// Returns an empty packet (length = 0)
+    pub fn new() -> Self {
+        let mut packet = Self {
+            buffer: [0; Self::SIZE],
+        };
+        packet.set_len(0);
+        packet
+    }
+
+    /// Fills the packet payload with given `src` data
+    ///
+    /// # Panics
+    ///
+    /// This function panics if `src` is larger than `Self::CAPACITY`
+    pub fn copy_from_slice(&mut self, src: &[u8]) {
+        assert!(src.len() <= Self::CAPACITY as usize);
+        let len = src.len() as u8;
+        self.buffer[Self::DATA][..len as usize].copy_from_slice(&src[..len.into()]);
+        self.set_len(len);
+    }
+
+    /// Returns the size of this packet's payload
+    pub fn len(&self) -> u8 {
+        self.buffer[Self::PHY_HDR] - Self::CRC
+    }
+
+    /// Changes the size of the packet's payload
+    ///
+    /// # Panics
+    ///
+    /// This function panics if `len` is larger than `Self::CAPACITY`
+    pub fn set_len(&mut self, len: u8) {
+        assert!(len <= Self::CAPACITY);
+        self.buffer[Self::PHY_HDR] = len + Self::CRC;
+    }
+
+    /// Returns the LQI (Link Quality Indicator) of the received packet
+    ///
+    /// Note that the LQI is stored in the `Packet`'s internal buffer by the hardware so the value
+    /// returned by this method is only valid after a `Radio.recv` operation. Operations that
+    /// modify the `Packet`, like `copy_from_slice` or `set_len`+`deref_mut`, will overwrite the
+    /// stored LQI value.
+    ///
+    /// Also note that the hardware will *not* compute a LQI for packets smaller than 3 bytes so
+    /// this method will return an invalid value for those packets.
+    pub fn lqi(&self) -> u8 {
+        self.buffer[1 /* PHY_HDR */ + self.len() as usize /* data */]
+    }
+}
+
+impl core::ops::Deref for Packet {
+    type Target = [u8];
+
+    fn deref(&self) -> &[u8] {
+        &self.buffer[Self::DATA][..self.len() as usize]
+    }
+}
+
+impl core::ops::DerefMut for Packet {
+    fn deref_mut(&mut self) -> &mut [u8] {
+        let len = self.len();
+        &mut self.buffer[Self::DATA][..len as usize]
+    }
+}
+
+/// NOTE must be followed by a volatile write operation
+fn dma_start_fence() {
+    compiler_fence(Ordering::Release);
+}
+
+/// NOTE must be preceded by a volatile read operation
+fn dma_end_fence() {
+    compiler_fence(Ordering::Acquire);
+}
diff --git a/embassy-nrf/src/radio/mod.rs b/embassy-nrf/src/radio/mod.rs
index 03f967f87..4c0cc3280 100644
--- a/embassy-nrf/src/radio/mod.rs
+++ b/embassy-nrf/src/radio/mod.rs
@@ -7,11 +7,40 @@
 
 /// Bluetooth Low Energy Radio driver.
 pub mod ble;
+#[cfg(any(
+    feature = "nrf52811",
+    feature = "nrf52820",
+    feature = "nrf52833",
+    feature = "nrf52840",
+    feature = "_nrf5340-net"
+))]
+/// IEEE 802.15.4
+pub mod ieee802154;
 
 use core::marker::PhantomData;
 
+use pac::radio::state::STATE_A as RadioState;
+pub use pac::radio::txpower::TXPOWER_A as TxPower;
+
 use crate::{interrupt, pac, Peripheral};
 
+/// RADIO error.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+#[non_exhaustive]
+pub enum Error {
+    /// Buffer was too long.
+    BufferTooLong,
+    /// Buffer was too short.
+    BufferTooShort,
+    /// The buffer is not in data RAM. It's most likely in flash, and nRF's DMA cannot access flash.
+    BufferNotInRAM,
+    /// Clear channel assessment reported channel in use
+    ChannelInUse,
+    /// CRC check failed
+    CrcFailed(u16),
+}
+
 /// Interrupt handler
 pub struct InterruptHandler<T: Instance> {
     _phantom: PhantomData<T>,
@@ -21,11 +50,9 @@ impl<T: Instance> interrupt::typelevel::Handler<T::Interrupt> for InterruptHandl
     unsafe fn on_interrupt() {
         let r = T::regs();
         let s = T::state();
-
-        if r.events_end.read().events_end().bit_is_set() {
-            s.end_waker.wake();
-            r.intenclr.write(|w| w.end().clear());
-        }
+        // clear all interrupts
+        r.intenclr.write(|w| w.bits(0xffff_ffff));
+        s.event_waker.wake();
     }
 }
 
@@ -34,12 +61,12 @@ pub(crate) mod sealed {
 
     pub struct State {
         /// end packet transmission or reception
-        pub end_waker: AtomicWaker,
+        pub event_waker: AtomicWaker,
     }
     impl State {
         pub const fn new() -> Self {
             Self {
-                end_waker: AtomicWaker::new(),
+                event_waker: AtomicWaker::new(),
             }
         }
     }
@@ -73,3 +100,11 @@ pub trait Instance: Peripheral<P = Self> + sealed::Instance + 'static + Send {
     /// Interrupt for this peripheral.
     type Interrupt: interrupt::typelevel::Interrupt;
 }
+
+/// Get the state of the radio
+pub(crate) fn state(radio: &pac::radio::RegisterBlock) -> RadioState {
+    match radio.state.read().state().variant() {
+        Some(state) => state,
+        None => unreachable!(),
+    }
+}
diff --git a/embassy-nrf/src/util.rs b/embassy-nrf/src/util.rs
index 6cdb97f08..13aba7dec 100644
--- a/embassy-nrf/src/util.rs
+++ b/embassy-nrf/src/util.rs
@@ -34,7 +34,6 @@ pub(crate) fn slice_in_ram<T>(slice: *const [T]) -> bool {
 }
 
 /// Return an error if slice is not in RAM. Skips check if slice is zero-length.
-#[cfg(not(feature = "nrf51"))]
 pub(crate) fn slice_in_ram_or<T, E>(slice: *const [T], err: E) -> Result<(), E> {
     let (_, len) = slice_ptr_parts(slice);
     if len == 0 || slice_in_ram(slice) {