make a copy of embassy-rs' i2c implementation

firmware/rust1/src/lib/i2c.rs

+// This is a modified copy of embassy/embassy-rp/src/i2c.rs.
+// We have changed:
+// - allow empty buffer for write (for I2C scan)
+// - don't block access to reserved addresses (also for I2C scan)
+
+use core::future;
+use core::marker::PhantomData;
+use core::task::Poll;
+
+use embassy_cortex_m::interrupt::InterruptExt;
+use embassy_hal_common::{into_ref, PeripheralRef};
+use embassy_sync::waitqueue::AtomicWaker;
+use pac::i2c;
+
+use crate::gpio::sealed::Pin;
+use crate::gpio::AnyPin;
+use crate::{pac, peripherals, Peripheral};
+
+/// I2C error abort reason
+#[derive(Debug)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum AbortReason {
+    /// A bus operation was not acknowledged, e.g. due to the addressed device
+    /// not being available on the bus or the device not being ready to process
+    /// requests at the moment
+    NoAcknowledge,
+    /// The arbitration was lost, e.g. electrical problems with the clock signal
+    ArbitrationLoss,
+    Other(u32),
+}
+
+/// I2C error
+#[derive(Debug)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum Error {
+    /// I2C abort with error
+    Abort(AbortReason),
+    /// User passed in a read buffer that was 0 length
+    InvalidReadBufferLength,
+    /// User passed in a write buffer that was 0 length
+    InvalidWriteBufferLength,
+    /// Target i2c address is out of range
+    AddressOutOfRange(u16),
+    /// Target i2c address is reserved
+    AddressReserved(u16),
+}
+
+#[non_exhaustive]
+#[derive(Copy, Clone)]
+pub struct Config {
+    pub frequency: u32,
+}
+
+impl Default for Config {
+    fn default() -> Self {
+        Self { frequency: 100_000 }
+    }
+}
+
+const FIFO_SIZE: u8 = 16;
+
+pub struct I2c<'d, T: Instance, M: Mode> {
+    phantom: PhantomData<(&'d mut T, M)>,
+}
+
+impl<'d, T: Instance> I2c<'d, T, Blocking> {
+    pub fn new_blocking(
+        peri: impl Peripheral<P = T> + 'd,
+        scl: impl Peripheral<P = impl SclPin<T>> + 'd,
+        sda: impl Peripheral<P = impl SdaPin<T>> + 'd,
+        config: Config,
+    ) -> Self {
+        into_ref!(scl, sda);
+        Self::new_inner(peri, scl.map_into(), sda.map_into(), config)
+    }
+}
+
+impl<'d, T: Instance> I2c<'d, T, Async> {
+    pub fn new_async(
+        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,
+        config: Config,
+    ) -> Self {
+        into_ref!(scl, sda, irq);
+
+        let i2c = Self::new_inner(peri, scl.map_into(), sda.map_into(), config);
+
+        irq.set_handler(Self::on_interrupt);
+        unsafe {
+            let i2c = T::regs();
+
+            // mask everything initially
+            i2c.ic_intr_mask().write_value(i2c::regs::IcIntrMask(0));
+        }
+        irq.unpend();
+        debug_assert!(!irq.is_pending());
+        irq.enable();
+
+        i2c
+    }
+
+    /// Calls `f` to check if we are ready or not.
+    /// If not, `g` is called once the waker is set (to eg enable the required interrupts).
+    async fn wait_on<F, U, G>(&mut self, mut f: F, mut g: G) -> U
+    where
+        F: FnMut(&mut Self) -> Poll<U>,
+        G: FnMut(&mut Self),
+    {
+        future::poll_fn(|cx| {
+            let r = f(self);
+
+            if r.is_pending() {
+                T::waker().register(cx.waker());
+                g(self);
+            }
+            r
+        })
+        .await
+    }
+
+    // Mask interrupts and wake any task waiting for this interrupt
+    unsafe fn on_interrupt(_: *mut ()) {
+        let i2c = T::regs();
+        i2c.ic_intr_mask().write_value(pac::i2c::regs::IcIntrMask::default());
+
+        T::waker().wake();
+    }
+
+    async fn read_async_internal(&mut self, buffer: &mut [u8], restart: bool, send_stop: bool) -> Result<(), Error> {
+        if buffer.is_empty() {
+            return Err(Error::InvalidReadBufferLength);
+        }
+
+        let p = T::regs();
+
+        let mut remaining = buffer.len();
+        let mut remaining_queue = buffer.len();
+
+        let mut abort_reason = Ok(());
+
+        while remaining > 0 {
+            // Waggle SCK - basically the same as write
+            let tx_fifo_space = Self::tx_fifo_capacity();
+            let mut batch = 0;
+
+            debug_assert!(remaining_queue > 0);
+
+            for _ in 0..remaining_queue.min(tx_fifo_space as usize) {
+                remaining_queue -= 1;
+                let last = remaining_queue == 0;
+                batch += 1;
+
+                unsafe {
+                    p.ic_data_cmd().write(|w| {
+                        w.set_restart(restart && remaining_queue == buffer.len() - 1);
+                        w.set_stop(last && send_stop);
+                        w.set_cmd(true);
+                    });
+                }
+            }
+
+            // We've either run out of txfifo or just plain finished setting up
+            // the clocks for the message - either way we need to wait for rx
+            // data.
+
+            debug_assert!(batch > 0);
+            let res = self
+                .wait_on(
+                    |me| {
+                        let rxfifo = Self::rx_fifo_len();
+                        if let Err(abort_reason) = me.read_and_clear_abort_reason() {
+                            Poll::Ready(Err(abort_reason))
+                        } else if rxfifo >= batch {
+                            Poll::Ready(Ok(rxfifo))
+                        } else {
+                            Poll::Pending
+                        }
+                    },
+                    |_me| unsafe {
+                        // Set the read threshold to the number of bytes we're
+                        // expecting so we don't get spurious interrupts.
+                        p.ic_rx_tl().write(|w| w.set_rx_tl(batch - 1));
+
+                        p.ic_intr_mask().modify(|w| {
+                            w.set_m_rx_full(true);
+                            w.set_m_tx_abrt(true);
+                        });
+                    },
+                )
+                .await;
+
+            match res {
+                Err(reason) => {
+                    abort_reason = Err(reason);
+                    break;
+                }
+                Ok(rxfifo) => {
+                    // Fetch things from rx fifo. We're assuming we're the only
+                    // rxfifo reader, so nothing else can take things from it.
+                    let rxbytes = (rxfifo as usize).min(remaining);
+                    let received = buffer.len() - remaining;
+                    for b in &mut buffer[received..received + rxbytes] {
+                        *b = unsafe { p.ic_data_cmd().read().dat() };
+                    }
+                    remaining -= rxbytes;
+                }
+            };
+        }
+
+        self.wait_stop_det(abort_reason, send_stop).await
+    }
+
+    async fn write_async_internal(
+        &mut self,
+        bytes: impl IntoIterator<Item = u8>,
+        send_stop: bool,
+    ) -> Result<(), Error> {
+        let p = T::regs();
+
+        let mut bytes = bytes.into_iter().peekable();
+
+        let res = 'xmit: loop {
+            let tx_fifo_space = Self::tx_fifo_capacity();
+
+            for _ in 0..tx_fifo_space {
+                if let Some(byte) = bytes.next() {
+                    let last = bytes.peek().is_none();
+
+                    unsafe {
+                        p.ic_data_cmd().write(|w| {
+                            w.set_stop(last && send_stop);
+                            w.set_cmd(false);
+                            w.set_dat(byte);
+                        });
+                    }
+                } else {
+                    break 'xmit Ok(());
+                }
+            }
+
+            let res = self
+                .wait_on(
+                    |me| {
+                        if let abort_reason @ Err(_) = me.read_and_clear_abort_reason() {
+                            Poll::Ready(abort_reason)
+                        } else if !Self::tx_fifo_full() {
+                            // resume if there's any space free in the tx fifo
+                            Poll::Ready(Ok(()))
+                        } else {
+                            Poll::Pending
+                        }
+                    },
+                    |_me| unsafe {
+                        // Set tx "free" threshold a little high so that we get
+                        // woken before the fifo completely drains to minimize
+                        // transfer stalls.
+                        p.ic_tx_tl().write(|w| w.set_tx_tl(1));
+
+                        p.ic_intr_mask().modify(|w| {
+                            w.set_m_tx_empty(true);
+                            w.set_m_tx_abrt(true);
+                        })
+                    },
+                )
+                .await;
+            if res.is_err() {
+                break res;
+            }
+        };
+
+        self.wait_stop_det(res, send_stop).await
+    }
+
+    /// Helper to wait for a stop bit, for both tx and rx. If we had an abort,
+    /// then we'll get a hardware-generated stop, otherwise wait for a stop if
+    /// we're expecting it.
+    ///
+    /// Also handles an abort which arises while processing the tx fifo.
+    async fn wait_stop_det(&mut self, had_abort: Result<(), Error>, do_stop: bool) -> Result<(), Error> {
+        if had_abort.is_err() || do_stop {
+            let p = T::regs();
+
+            let had_abort2 = self
+                .wait_on(
+                    |me| unsafe {
+                        // We could see an abort while processing fifo backlog,
+                        // so handle it here.
+                        let abort = me.read_and_clear_abort_reason();
+                        if had_abort.is_ok() && abort.is_err() {
+                            Poll::Ready(abort)
+                        } else if p.ic_raw_intr_stat().read().stop_det() {
+                            Poll::Ready(Ok(()))
+                        } else {
+                            Poll::Pending
+                        }
+                    },
+                    |_me| unsafe {
+                        p.ic_intr_mask().modify(|w| {
+                            w.set_m_stop_det(true);
+                            w.set_m_tx_abrt(true);
+                        });
+                    },
+                )
+                .await;
+            unsafe {
+                p.ic_clr_stop_det().read();
+            }
+
+            had_abort.and(had_abort2)
+        } else {
+            had_abort
+        }
+    }
+
+    pub async fn read_async(&mut self, addr: u16, buffer: &mut [u8]) -> Result<(), Error> {
+        Self::setup(addr)?;
+        self.read_async_internal(buffer, false, true).await
+    }
+
+    pub async fn write_async(&mut self, addr: u16, bytes: impl IntoIterator<Item = u8>) -> Result<(), Error> {
+        Self::setup(addr)?;
+        self.write_async_internal(bytes, true).await
+    }
+}
+
+impl<'d, T: Instance + 'd, M: Mode> I2c<'d, T, M> {
+    fn new_inner(
+        _peri: impl Peripheral<P = T> + 'd,
+        scl: PeripheralRef<'d, AnyPin>,
+        sda: PeripheralRef<'d, AnyPin>,
+        config: Config,
+    ) -> Self {
+        into_ref!(_peri);
+
+        assert!(config.frequency <= 1_000_000);
+        assert!(config.frequency > 0);
+
+        let p = T::regs();
+
+        unsafe {
+            let reset = T::reset();
+            crate::reset::reset(reset);
+            crate::reset::unreset_wait(reset);
+
+            p.ic_enable().write(|w| w.set_enable(false));
+
+            // Select controller mode & speed
+            p.ic_con().modify(|w| {
+                // Always use "fast" mode (<= 400 kHz, works fine for standard
+                // mode too)
+                w.set_speed(i2c::vals::Speed::FAST);
+                w.set_master_mode(true);
+                w.set_ic_slave_disable(true);
+                w.set_ic_restart_en(true);
+                w.set_tx_empty_ctrl(true);
+            });
+
+            // Set FIFO watermarks to 1 to make things simpler. This is encoded
+            // by a register value of 0.
+            p.ic_tx_tl().write(|w| w.set_tx_tl(0));
+            p.ic_rx_tl().write(|w| w.set_rx_tl(0));
+
+            // Configure SCL & SDA pins
+            scl.io().ctrl().write(|w| w.set_funcsel(3));
+            sda.io().ctrl().write(|w| w.set_funcsel(3));
+
+            scl.pad_ctrl().write(|w| {
+                w.set_schmitt(true);
+                w.set_ie(true);
+                w.set_od(false);
+                w.set_pue(true);
+                w.set_pde(false);
+            });
+            sda.pad_ctrl().write(|w| {
+                w.set_schmitt(true);
+                w.set_ie(true);
+                w.set_od(false);
+                w.set_pue(true);
+                w.set_pde(false);
+            });
+
+            // Configure baudrate
+
+            // There are some subtleties to I2C timing which we are completely
+            // ignoring here See:
+            // https://github.com/raspberrypi/pico-sdk/blob/bfcbefafc5d2a210551a4d9d80b4303d4ae0adf7/src/rp2_common/hardware_i2c/i2c.c#L69
+            let clk_base = crate::clocks::clk_peri_freq();
+
+            let period = (clk_base + config.frequency / 2) / config.frequency;
+            let lcnt = period * 3 / 5; // spend 3/5 (60%) of the period low
+            let hcnt = period - lcnt; // and 2/5 (40%) of the period high
+
+            // Check for out-of-range divisors:
+            assert!(hcnt <= 0xffff);
+            assert!(lcnt <= 0xffff);
+            assert!(hcnt >= 8);
+            assert!(lcnt >= 8);
+
+            // Per I2C-bus specification a device in standard or fast mode must
+            // internally provide a hold time of at least 300ns for the SDA
+            // signal to bridge the undefined region of the falling edge of SCL.
+            // A smaller hold time of 120ns is used for fast mode plus.
+            let sda_tx_hold_count = if config.frequency < 1_000_000 {
+                // sda_tx_hold_count = clk_base [cycles/s] * 300ns * (1s /
+                // 1e9ns) Reduce 300/1e9 to 3/1e7 to avoid numbers that don't
+                // fit in uint. Add 1 to avoid division truncation.
+                ((clk_base * 3) / 10_000_000) + 1
+            } else {
+                // fast mode plus requires a clk_base > 32MHz
+                assert!(clk_base >= 32_000_000);
+
+                // sda_tx_hold_count = clk_base [cycles/s] * 120ns * (1s /
+                // 1e9ns) Reduce 120/1e9 to 3/25e6 to avoid numbers that don't
+                // fit in uint. Add 1 to avoid division truncation.
+                ((clk_base * 3) / 25_000_000) + 1
+            };
+            assert!(sda_tx_hold_count <= lcnt - 2);
+
+            p.ic_fs_scl_hcnt().write(|w| w.set_ic_fs_scl_hcnt(hcnt as u16));
+            p.ic_fs_scl_lcnt().write(|w| w.set_ic_fs_scl_lcnt(lcnt as u16));
+            p.ic_fs_spklen()
+                .write(|w| w.set_ic_fs_spklen(if lcnt < 16 { 1 } else { (lcnt / 16) as u8 }));
+            p.ic_sda_hold()
+                .modify(|w| w.set_ic_sda_tx_hold(sda_tx_hold_count as u16));
+
+            // Enable I2C block
+            p.ic_enable().write(|w| w.set_enable(true));
+        }
+
+        Self { phantom: PhantomData }
+    }
+
+    fn setup(addr: u16) -> Result<(), Error> {
+        if addr >= 0x80 {
+            return Err(Error::AddressOutOfRange(addr));
+        }
+
+        if i2c_reserved_addr(addr) {
+            return Err(Error::AddressReserved(addr));
+        }
+
+        let p = T::regs();
+        unsafe {
+            p.ic_enable().write(|w| w.set_enable(false));
+            p.ic_tar().write(|w| w.set_ic_tar(addr));
+            p.ic_enable().write(|w| w.set_enable(true));
+        }
+        Ok(())
+    }
+
+    #[inline]
+    fn tx_fifo_full() -> bool {
+        Self::tx_fifo_capacity() == 0
+    }
+
+    #[inline]
+    fn tx_fifo_capacity() -> u8 {
+        let p = T::regs();
+        unsafe { FIFO_SIZE - p.ic_txflr().read().txflr() }
+    }
+
+    #[inline]
+    fn rx_fifo_len() -> u8 {
+        let p = T::regs();
+        unsafe { p.ic_rxflr().read().rxflr() }
+    }
+
+    fn read_and_clear_abort_reason(&mut self) -> Result<(), Error> {
+        let p = T::regs();
+        unsafe {
+            let abort_reason = p.ic_tx_abrt_source().read();
+            if abort_reason.0 != 0 {
+                // Note clearing the abort flag also clears the reason, and this
+                // instance of flag is clear-on-read! Note also the
+                // IC_CLR_TX_ABRT register always reads as 0.
+                p.ic_clr_tx_abrt().read();
+
+                let reason = if abort_reason.abrt_7b_addr_noack()
+                    | abort_reason.abrt_10addr1_noack()
+                    | abort_reason.abrt_10addr2_noack()
+                {
+                    AbortReason::NoAcknowledge
+                } else if abort_reason.arb_lost() {
+                    AbortReason::ArbitrationLoss
+                } else {
+                    AbortReason::Other(abort_reason.0)
+                };
+
+                Err(Error::Abort(reason))
+            } else {
+                Ok(())
+            }
+        }
+    }
+
+    fn read_blocking_internal(&mut self, read: &mut [u8], restart: bool, send_stop: bool) -> Result<(), Error> {
+        if read.is_empty() {
+            return Err(Error::InvalidReadBufferLength);
+        }
+
+        let p = T::regs();
+        let lastindex = read.len() - 1;
+        for (i, byte) in read.iter_mut().enumerate() {
+            let first = i == 0;
+            let last = i == lastindex;
+
+            // NOTE(unsafe) We have &mut self
+            unsafe {
+                // wait until there is space in the FIFO to write the next byte
+                while Self::tx_fifo_full() {}
+
+                p.ic_data_cmd().write(|w| {
+                    w.set_restart(restart && first);
+                    w.set_stop(send_stop && last);
+
+                    w.set_cmd(true);
+                });
+
+                while Self::rx_fifo_len() == 0 {
+                    self.read_and_clear_abort_reason()?;
+                }
+
+                *byte = p.ic_data_cmd().read().dat();
+            }
+        }
+
+        Ok(())
+    }
+
+    fn write_blocking_internal(&mut self, write: &[u8], send_stop: bool) -> Result<(), Error> {
+        if write.is_empty() {
+            return Err(Error::InvalidWriteBufferLength);
+        }
+
+        let p = T::regs();
+
+        for (i, byte) in write.iter().enumerate() {
+            let last = i == write.len() - 1;
+
+            // NOTE(unsafe) We have &mut self
+            unsafe {
+                p.ic_data_cmd().write(|w| {
+                    w.set_stop(send_stop && last);
+                    w.set_dat(*byte);
+                });
+
+                // Wait until the transmission of the address/data from the
+                // internal shift register has completed. For this to function
+                // correctly, the TX_EMPTY_CTRL flag in IC_CON must be set. The
+                // TX_EMPTY_CTRL flag was set in i2c_init.
+                while !p.ic_raw_intr_stat().read().tx_empty() {}
+
+                let abort_reason = self.read_and_clear_abort_reason();
+
+                if abort_reason.is_err() || (send_stop && last) {
+                    // If the transaction was aborted or if it completed
+                    // successfully wait until the STOP condition has occurred.
+
+                    while !p.ic_raw_intr_stat().read().stop_det() {}
+
+                    p.ic_clr_stop_det().read().clr_stop_det();
+                }
+
+                // Note the hardware issues a STOP automatically on an abort
+                // condition. Note also the hardware clears RX FIFO as well as
+                // TX on abort, ecause we set hwparam
+                // IC_AVOID_RX_FIFO_FLUSH_ON_TX_ABRT to 0.
+                abort_reason?;
+            }
+        }
+        Ok(())
+    }
+
+    // =========================
+    // Blocking public API
+    // =========================
+
+    pub fn blocking_read(&mut self, address: u8, read: &mut [u8]) -> Result<(), Error> {
+        Self::setup(address.into())?;
+        self.read_blocking_internal(read, true, true)
+        // Automatic Stop
+    }
+
+    pub fn blocking_write(&mut self, address: u8, write: &[u8]) -> Result<(), Error> {
+        Self::setup(address.into())?;
+        self.write_blocking_internal(write, true)
+    }
+
+    pub fn blocking_write_read(&mut self, address: u8, write: &[u8], read: &mut [u8]) -> Result<(), Error> {
+        Self::setup(address.into())?;
+        self.write_blocking_internal(write, false)?;
+        self.read_blocking_internal(read, true, true)
+        // Automatic Stop
+    }
+}
+
+mod eh02 {
+    use super::*;
+
+    impl<'d, T: Instance, M: Mode> embedded_hal_02::blocking::i2c::Read for I2c<'d, T, M> {
+        type Error = Error;
+
+        fn read(&mut self, address: u8, buffer: &mut [u8]) -> Result<(), Self::Error> {
+            self.blocking_read(address, buffer)
+        }
+    }
+
+    impl<'d, T: Instance, M: Mode> embedded_hal_02::blocking::i2c::Write for I2c<'d, T, M> {
+        type Error = Error;
+
+        fn write(&mut self, address: u8, bytes: &[u8]) -> Result<(), Self::Error> {
+            self.blocking_write(address, bytes)
+        }
+    }
+
+    impl<'d, T: Instance, M: Mode> embedded_hal_02::blocking::i2c::WriteRead for I2c<'d, T, M> {
+        type Error = Error;
+
+        fn write_read(&mut self, address: u8, bytes: &[u8], buffer: &mut [u8]) -> Result<(), Self::Error> {
+            self.blocking_write_read(address, bytes, buffer)
+        }
+    }
+
+    impl<'d, T: Instance, M: Mode> embedded_hal_02::blocking::i2c::Transactional for I2c<'d, T, M> {
+        type Error = Error;
+
+        fn exec(
+            &mut self,
+            address: u8,
+            operations: &mut [embedded_hal_02::blocking::i2c::Operation<'_>],
+        ) -> Result<(), Self::Error> {
+            Self::setup(address.into())?;
+            for i in 0..operations.len() {
+                let last = i == operations.len() - 1;
+                match &mut operations[i] {
+                    embedded_hal_02::blocking::i2c::Operation::Read(buf) => {
+                        self.read_blocking_internal(buf, false, last)?
+                    }
+                    embedded_hal_02::blocking::i2c::Operation::Write(buf) => self.write_blocking_internal(buf, last)?,
+                }
+            }
+            Ok(())
+        }
+    }
+}
+
+#[cfg(feature = "unstable-traits")]
+mod eh1 {
+    use super::*;
+
+    impl embedded_hal_1::i2c::Error for Error {
+        fn kind(&self) -> embedded_hal_1::i2c::ErrorKind {
+            match *self {
+                Self::Abort(AbortReason::ArbitrationLoss) => embedded_hal_1::i2c::ErrorKind::ArbitrationLoss,
+                Self::Abort(AbortReason::NoAcknowledge) => {
+                    embedded_hal_1::i2c::ErrorKind::NoAcknowledge(embedded_hal_1::i2c::NoAcknowledgeSource::Address)
+                }
+                Self::Abort(AbortReason::Other(_)) => embedded_hal_1::i2c::ErrorKind::Other,
+                Self::InvalidReadBufferLength => embedded_hal_1::i2c::ErrorKind::Other,
+                Self::InvalidWriteBufferLength => embedded_hal_1::i2c::ErrorKind::Other,
+                Self::AddressOutOfRange(_) => embedded_hal_1::i2c::ErrorKind::Other,
+                Self::AddressReserved(_) => embedded_hal_1::i2c::ErrorKind::Other,
+            }
+        }
+    }
+
+    impl<'d, T: Instance, M: Mode> embedded_hal_1::i2c::ErrorType for I2c<'d, T, M> {
+        type Error = Error;
+    }
+
+    impl<'d, T: Instance, M: Mode> embedded_hal_1::i2c::I2c for I2c<'d, T, M> {
+        fn read(&mut self, address: u8, read: &mut [u8]) -> Result<(), Self::Error> {
+            self.blocking_read(address, read)
+        }
+
+        fn write(&mut self, address: u8, write: &[u8]) -> Result<(), Self::Error> {
+            self.blocking_write(address, write)
+        }
+
+        fn write_read(&mut self, address: u8, write: &[u8], read: &mut [u8]) -> Result<(), Self::Error> {
+            self.blocking_write_read(address, write, read)
+        }
+
+        fn transaction(
+            &mut self,
+            address: u8,
+            operations: &mut [embedded_hal_1::i2c::Operation<'_>],
+        ) -> Result<(), Self::Error> {
+            Self::setup(address.into())?;
+            for i in 0..operations.len() {
+                let last = i == operations.len() - 1;
+                match &mut operations[i] {
+                    embedded_hal_1::i2c::Operation::Read(buf) => self.read_blocking_internal(buf, false, last)?,
+                    embedded_hal_1::i2c::Operation::Write(buf) => self.write_blocking_internal(buf, last)?,
+                }
+            }
+            Ok(())
+        }
+    }
+}
+#[cfg(all(feature = "unstable-traits", feature = "nightly"))]
+mod nightly {
+    use embedded_hal_1::i2c::Operation;
+    use embedded_hal_async::i2c::AddressMode;
+
+    use super::*;
+
+    impl<'d, A, T> embedded_hal_async::i2c::I2c<A> for I2c<'d, T, Async>
+    where
+        A: AddressMode + Into<u16> + 'static,
+        T: Instance + 'd,
+    {
+        async fn read(&mut self, address: A, read: &mut [u8]) -> Result<(), Self::Error> {
+            let addr: u16 = address.into();
+
+            Self::setup(addr)?;
+            self.read_async_internal(read, false, true).await
+        }
+
+        async fn write(&mut self, address: A, write: &[u8]) -> Result<(), Self::Error> {
+            let addr: u16 = address.into();
+
+            Self::setup(addr)?;
+            self.write_async_internal(write.iter().copied(), true).await
+        }
+
+        async fn write_read(&mut self, address: A, write: &[u8], read: &mut [u8]) -> Result<(), Self::Error> {
+            let addr: u16 = address.into();
+
+            Self::setup(addr)?;
+            self.write_async_internal(write.iter().cloned(), false).await?;
+            self.read_async_internal(read, false, true).await
+        }
+
+        async fn transaction(&mut self, address: A, operations: &mut [Operation<'_>]) -> Result<(), Self::Error> {
+            let addr: u16 = address.into();
+
+            let mut iterator = operations.iter_mut();
+
+            while let Some(op) = iterator.next() {
+                let last = iterator.len() == 0;
+
+                match op {
+                    Operation::Read(buffer) => {
+                        Self::setup(addr)?;
+                        self.read_async_internal(buffer, false, last).await?;
+                    }
+                    Operation::Write(buffer) => {
+                        Self::setup(addr)?;
+                        self.write_async_internal(buffer.into_iter().cloned(), last).await?;
+                    }
+                }
+            }
+            Ok(())
+        }
+    }
+}
+
+fn i2c_reserved_addr(addr: u16) -> bool {
+    (addr & 0x78) == 0 || (addr & 0x78) == 0x78
+}
+
+mod sealed {
+    use embassy_cortex_m::interrupt::Interrupt;
+    use embassy_sync::waitqueue::AtomicWaker;
+
+    pub trait Instance {
+        const TX_DREQ: u8;
+        const RX_DREQ: u8;
+
+        type Interrupt: Interrupt;
+
+        fn regs() -> crate::pac::i2c::I2c;
+        fn reset() -> crate::pac::resets::regs::Peripherals;
+        fn waker() -> &'static AtomicWaker;
+    }
+
+    pub trait Mode {}
+
+    pub trait SdaPin<T: Instance> {}
+    pub trait SclPin<T: Instance> {}
+}
+
+pub trait Mode: sealed::Mode {}
+
+macro_rules! impl_mode {
+    ($name:ident) => {
+        impl sealed::Mode for $name {}
+        impl Mode for $name {}
+    };
+}
+
+pub struct Blocking;
+pub struct Async;
+
+impl_mode!(Blocking);
+impl_mode!(Async);
+
+pub trait Instance: sealed::Instance {}
+
+macro_rules! impl_instance {
+    ($type:ident, $irq:ident, $reset:ident, $tx_dreq:expr, $rx_dreq:expr) => {
+        impl sealed::Instance for peripherals::$type {
+            const TX_DREQ: u8 = $tx_dreq;
+            const RX_DREQ: u8 = $rx_dreq;
+
+            type Interrupt = crate::interrupt::$irq;
+
+            #[inline]
+            fn regs() -> pac::i2c::I2c {
+                pac::$type
+            }
+
+            #[inline]
+            fn reset() -> pac::resets::regs::Peripherals {
+                let mut ret = pac::resets::regs::Peripherals::default();
+                ret.$reset(true);
+                ret
+            }
+
+            #[inline]
+            fn waker() -> &'static AtomicWaker {
+                static WAKER: AtomicWaker = AtomicWaker::new();
+
+                &WAKER
+            }
+        }
+        impl Instance for peripherals::$type {}
+    };
+}
+
+impl_instance!(I2C0, I2C0_IRQ, set_i2c0, 32, 33);
+impl_instance!(I2C1, I2C1_IRQ, set_i2c1, 34, 35);
+
+pub trait SdaPin<T: Instance>: sealed::SdaPin<T> + crate::gpio::Pin {}
+pub trait SclPin<T: Instance>: sealed::SclPin<T> + crate::gpio::Pin {}
+
+macro_rules! impl_pin {
+    ($pin:ident, $instance:ident, $function:ident) => {
+        impl sealed::$function<peripherals::$instance> for peripherals::$pin {}
+        impl $function<peripherals::$instance> for peripherals::$pin {}
+    };
+}
+
+impl_pin!(PIN_0, I2C0, SdaPin);
+impl_pin!(PIN_1, I2C0, SclPin);
+impl_pin!(PIN_2, I2C1, SdaPin);
+impl_pin!(PIN_3, I2C1, SclPin);
+impl_pin!(PIN_4, I2C0, SdaPin);
+impl_pin!(PIN_5, I2C0, SclPin);
+impl_pin!(PIN_6, I2C1, SdaPin);
+impl_pin!(PIN_7, I2C1, SclPin);
+impl_pin!(PIN_8, I2C0, SdaPin);
+impl_pin!(PIN_9, I2C0, SclPin);
+impl_pin!(PIN_10, I2C1, SdaPin);
+impl_pin!(PIN_11, I2C1, SclPin);
+impl_pin!(PIN_12, I2C0, SdaPin);
+impl_pin!(PIN_13, I2C0, SclPin);
+impl_pin!(PIN_14, I2C1, SdaPin);
+impl_pin!(PIN_15, I2C1, SclPin);
+impl_pin!(PIN_16, I2C0, SdaPin);
+impl_pin!(PIN_17, I2C0, SclPin);
+impl_pin!(PIN_18, I2C1, SdaPin);
+impl_pin!(PIN_19, I2C1, SclPin);
+impl_pin!(PIN_20, I2C0, SdaPin);
+impl_pin!(PIN_21, I2C0, SclPin);
+impl_pin!(PIN_22, I2C1, SdaPin);
+impl_pin!(PIN_23, I2C1, SclPin);
+impl_pin!(PIN_24, I2C0, SdaPin);
+impl_pin!(PIN_25, I2C0, SclPin);
+impl_pin!(PIN_26, I2C1, SdaPin);
+impl_pin!(PIN_27, I2C1, SclPin);
+impl_pin!(PIN_28, I2C0, SdaPin);
+impl_pin!(PIN_29, I2C0, SclPin);