diff --git a/embassy-rp/src/i2c.rs b/embassy-rp/src/i2c.rs new file mode 100644 index 00000000..9596d661 --- /dev/null +++ b/embassy-rp/src/i2c.rs @@ -0,0 +1,556 @@ +use core::marker::PhantomData; + +use embassy_hal_common::{into_ref, PeripheralRef}; +use pac::i2c; + +use crate::dma::AnyChannel; +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> { + _tx_dma: Option>, + _rx_dma: Option>, + _dma_buf: [u16; 256], + phantom: PhantomData<(&'d mut T, M)>, +} + +impl<'d, T: Instance> I2c<'d, T, Blocking> { + pub fn new_blocking( + _peri: impl Peripheral

+ 'd, + scl: impl Peripheral

> + 'd, + sda: impl Peripheral

> + 'd, + config: Config, + ) -> Self { + into_ref!(scl, sda); + Self::new_inner(_peri, scl.map_into(), sda.map_into(), None, None, config) + } +} + +impl<'d, T: Instance, M: Mode> I2c<'d, T, M> { + fn new_inner( + _peri: impl Peripheral

+ 'd, + scl: PeripheralRef<'d, AnyPin>, + sda: PeripheralRef<'d, AnyPin>, + _tx_dma: Option>, + _rx_dma: Option>, + config: Config, + ) -> Self { + into_ref!(_peri); + + assert!(config.frequency <= 1_000_000); + assert!(config.frequency > 0); + + let p = T::regs(); + + unsafe { + 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 { + _tx_dma, + _rx_dma, + _dma_buf: [0; 256], + 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(()) + } + + 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, buffer: &mut [u8], restart: bool, send_stop: bool) -> Result<(), Error> { + if buffer.is_empty() { + return Err(Error::InvalidReadBufferLength); + } + + let p = T::regs(); + let lastindex = buffer.len() - 1; + for (i, byte) in buffer.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 p.ic_txflr().read().txflr() == FIFO_SIZE {} + + p.ic_data_cmd().write(|w| { + w.set_restart(restart && first); + w.set_stop(send_stop && last); + + w.set_cmd(true); + }); + + while p.ic_rxflr().read().rxflr() == 0 { + self.read_and_clear_abort_reason()?; + } + + *byte = p.ic_data_cmd().read().dat(); + } + } + + Ok(()) + } + + fn write_blocking_internal(&mut self, bytes: &[u8], send_stop: bool) -> Result<(), Error> { + if bytes.is_empty() { + return Err(Error::InvalidWriteBufferLength); + } + + let p = T::regs(); + + for (i, byte) in bytes.iter().enumerate() { + let last = i == bytes.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 occured. + + 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, buffer: &mut [u8]) -> Result<(), Error> { + Self::setup(address.into())?; + self.read_blocking_internal(buffer, true, true) + // Automatic Stop + } + + pub fn blocking_write(&mut self, address: u8, bytes: &[u8]) -> Result<(), Error> { + Self::setup(address.into())?; + self.write_blocking_internal(bytes, true) + } + + pub fn blocking_write_read(&mut self, address: u8, bytes: &[u8], buffer: &mut [u8]) -> Result<(), Error> { + Self::setup(address.into())?; + self.write_blocking_internal(bytes, false)?; + self.read_blocking_internal(buffer, 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) + } + } +} + +#[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::blocking::I2c for I2c<'d, T, M> { + fn read(&mut self, address: u8, buffer: &mut [u8]) -> Result<(), Self::Error> { + self.blocking_read(address, buffer) + } + + fn write(&mut self, address: u8, buffer: &[u8]) -> Result<(), Self::Error> { + self.blocking_write(address, buffer) + } + + fn write_iter(&mut self, address: u8, bytes: B) -> Result<(), Self::Error> + where + B: IntoIterator, + { + let mut peekable = bytes.into_iter().peekable(); + Self::setup(address.into())?; + + while let Some(tx) = peekable.next() { + self.write_blocking_internal(&[tx], peekable.peek().is_none())?; + } + Ok(()) + } + + fn write_iter_read(&mut self, address: u8, bytes: B, buffer: &mut [u8]) -> Result<(), Self::Error> + where + B: IntoIterator, + { + let peekable = bytes.into_iter().peekable(); + Self::setup(address.into())?; + + for tx in peekable { + self.write_blocking_internal(&[tx], false)? + } + self.read_blocking_internal(buffer, true, true) + } + + fn write_read(&mut self, address: u8, wr_buffer: &[u8], rd_buffer: &mut [u8]) -> Result<(), Self::Error> { + self.blocking_write_read(address, wr_buffer, rd_buffer) + } + + fn transaction<'a>( + &mut self, + address: u8, + operations: &mut [embedded_hal_1::i2c::blocking::Operation<'a>], + ) -> 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::blocking::Operation::Read(buf) => { + self.read_blocking_internal(buf, false, last)? + } + embedded_hal_1::i2c::blocking::Operation::Write(buf) => self.write_blocking_internal(buf, last)?, + } + } + Ok(()) + } + + fn transaction_iter<'a, O>(&mut self, address: u8, operations: O) -> Result<(), Self::Error> + where + O: IntoIterator>, + { + Self::setup(address.into())?; + let mut peekable = operations.into_iter().peekable(); + while let Some(operation) = peekable.next() { + let last = peekable.peek().is_none(); + match operation { + embedded_hal_1::i2c::blocking::Operation::Read(buf) => { + self.read_blocking_internal(buf, false, last)? + } + embedded_hal_1::i2c::blocking::Operation::Write(buf) => self.write_blocking_internal(buf, last)?, + } + } + Ok(()) + } + } +} + +fn i2c_reserved_addr(addr: u16) -> bool { + (addr & 0x78) == 0 || (addr & 0x78) == 0x78 +} + +mod sealed { + use embassy_cortex_m::interrupt::Interrupt; + + pub trait Instance { + const TX_DREQ: u8; + const RX_DREQ: u8; + + type Interrupt: Interrupt; + + fn regs() -> crate::pac::i2c::I2c; + } + + pub trait Mode {} + + pub trait SdaPin {} + pub trait SclPin {} +} + +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, $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; + + fn regs() -> pac::i2c::I2c { + pac::$type + } + } + impl Instance for peripherals::$type {} + }; +} + +impl_instance!(I2C0, I2C0_IRQ, 32, 33); +impl_instance!(I2C1, I2C1_IRQ, 34, 35); + +pub trait SdaPin: sealed::SdaPin + crate::gpio::Pin {} +pub trait SclPin: sealed::SclPin + crate::gpio::Pin {} + +macro_rules! impl_pin { + ($pin:ident, $instance:ident, $function:ident) => { + impl sealed::$function for peripherals::$pin {} + impl $function for peripherals::$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); diff --git a/embassy-rp/src/lib.rs b/embassy-rp/src/lib.rs index 9ac98d22..e784399d 100644 --- a/embassy-rp/src/lib.rs +++ b/embassy-rp/src/lib.rs @@ -8,6 +8,7 @@ mod intrinsics; pub mod dma; pub mod gpio; +pub mod i2c; pub mod interrupt; pub mod rom_data; pub mod rtc; @@ -75,6 +76,9 @@ embassy_hal_common::peripherals! { SPI0, SPI1, + I2C0, + I2C1, + DMA_CH0, DMA_CH1, DMA_CH2, diff --git a/embassy-rp/src/uart/mod.rs b/embassy-rp/src/uart/mod.rs index d9285ee5..567c79db 100644 --- a/embassy-rp/src/uart/mod.rs +++ b/embassy-rp/src/uart/mod.rs @@ -428,9 +428,11 @@ mod eh02 { impl<'d, T: Instance, M: Mode> embedded_hal_02::blocking::serial::Write for UartTx<'d, T, M> { type Error = Error; + fn bwrite_all(&mut self, buffer: &[u8]) -> Result<(), Self::Error> { self.blocking_write(buffer) } + fn bflush(&mut self) -> Result<(), Self::Error> { self.blocking_flush() } @@ -438,6 +440,7 @@ mod eh02 { impl<'d, T: Instance, M: Mode> embedded_hal_02::serial::Read for Uart<'d, T, M> { type Error = Error; + fn read(&mut self) -> Result> { embedded_hal_02::serial::Read::read(&mut self.rx) } @@ -445,9 +448,11 @@ mod eh02 { impl<'d, T: Instance, M: Mode> embedded_hal_02::blocking::serial::Write for Uart<'d, T, M> { type Error = Error; + fn bwrite_all(&mut self, buffer: &[u8]) -> Result<(), Self::Error> { self.blocking_write(buffer) } + fn bflush(&mut self) -> Result<(), Self::Error> { self.blocking_flush() }