use core::marker::PhantomData; use embassy_embedded_hal::SetConfig; use embassy_futures::join::join; use embassy_hal_common::{into_ref, PeripheralRef}; pub use embedded_hal_02::spi::{Phase, Polarity}; use crate::dma::{AnyChannel, Channel}; use crate::gpio::sealed::Pin as _; use crate::gpio::{AnyPin, Pin as GpioPin}; use crate::{pac, peripherals, Peripheral}; #[derive(Debug, Clone, Copy, PartialEq, Eq)] #[cfg_attr(feature = "defmt", derive(defmt::Format))] #[non_exhaustive] pub enum Error { // No errors for now } #[non_exhaustive] pub struct Config { pub frequency: u32, pub phase: Phase, pub polarity: Polarity, } impl Default for Config { fn default() -> Self { Self { frequency: 1_000_000, phase: Phase::CaptureOnFirstTransition, polarity: Polarity::IdleLow, } } } pub struct Spi<'d, T: Instance, M: Mode> { inner: PeripheralRef<'d, T>, tx_dma: Option>, rx_dma: Option>, phantom: PhantomData<(&'d mut T, M)>, } fn div_roundup(a: u32, b: u32) -> u32 { (a + b - 1) / b } fn calc_prescs(freq: u32) -> (u8, u8) { let clk_peri = crate::clocks::clk_peri_freq(); // final SPI frequency: spi_freq = clk_peri / presc / postdiv // presc must be in 2..=254, and must be even // postdiv must be in 1..=256 // divide extra by 2, so we get rid of the "presc must be even" requirement let ratio = div_roundup(clk_peri, freq * 2); if ratio > 127 * 256 { panic!("Requested too low SPI frequency"); } let presc = div_roundup(ratio, 256); let postdiv = if presc == 1 { ratio } else { div_roundup(ratio, presc) }; ((presc * 2) as u8, (postdiv - 1) as u8) } impl<'d, T: Instance, M: Mode> Spi<'d, T, M> { fn new_inner( inner: impl Peripheral

+ 'd, clk: Option>, mosi: Option>, miso: Option>, cs: Option>, tx_dma: Option>, rx_dma: Option>, config: Config, ) -> Self { into_ref!(inner); unsafe { let p = inner.regs(); let (presc, postdiv) = calc_prescs(config.frequency); p.cpsr().write(|w| w.set_cpsdvsr(presc)); p.cr0().write(|w| { w.set_dss(0b0111); // 8bit w.set_spo(config.polarity == Polarity::IdleHigh); w.set_sph(config.phase == Phase::CaptureOnSecondTransition); w.set_scr(postdiv); }); p.cr1().write(|w| { w.set_sse(true); // enable }); if let Some(pin) = &clk { pin.io().ctrl().write(|w| w.set_funcsel(1)); } if let Some(pin) = &mosi { pin.io().ctrl().write(|w| w.set_funcsel(1)); } if let Some(pin) = &miso { pin.io().ctrl().write(|w| w.set_funcsel(1)); } if let Some(pin) = &cs { pin.io().ctrl().write(|w| w.set_funcsel(1)); } } Self { inner, tx_dma, rx_dma, phantom: PhantomData, } } pub fn blocking_write(&mut self, data: &[u8]) -> Result<(), Error> { unsafe { let p = self.inner.regs(); for &b in data { while !p.sr().read().tnf() {} p.dr().write(|w| w.set_data(b as _)); while !p.sr().read().rne() {} let _ = p.dr().read(); } } self.flush()?; Ok(()) } pub fn blocking_transfer_in_place(&mut self, data: &mut [u8]) -> Result<(), Error> { unsafe { let p = self.inner.regs(); for b in data { while !p.sr().read().tnf() {} p.dr().write(|w| w.set_data(*b as _)); while !p.sr().read().rne() {} *b = p.dr().read().data() as u8; } } self.flush()?; Ok(()) } pub fn blocking_read(&mut self, data: &mut [u8]) -> Result<(), Error> { unsafe { let p = self.inner.regs(); for b in data { while !p.sr().read().tnf() {} p.dr().write(|w| w.set_data(0)); while !p.sr().read().rne() {} *b = p.dr().read().data() as u8; } } self.flush()?; Ok(()) } pub fn blocking_transfer(&mut self, read: &mut [u8], write: &[u8]) -> Result<(), Error> { unsafe { let p = self.inner.regs(); let len = read.len().max(write.len()); for i in 0..len { let wb = write.get(i).copied().unwrap_or(0); while !p.sr().read().tnf() {} p.dr().write(|w| w.set_data(wb as _)); while !p.sr().read().rne() {} let rb = p.dr().read().data() as u8; if let Some(r) = read.get_mut(i) { *r = rb; } } } self.flush()?; Ok(()) } pub fn flush(&mut self) -> Result<(), Error> { unsafe { let p = self.inner.regs(); while p.sr().read().bsy() {} } Ok(()) } pub fn set_frequency(&mut self, freq: u32) { let (presc, postdiv) = calc_prescs(freq); let p = self.inner.regs(); unsafe { // disable p.cr1().write(|w| w.set_sse(false)); // change stuff p.cpsr().write(|w| w.set_cpsdvsr(presc)); p.cr0().modify(|w| { w.set_scr(postdiv); }); // enable p.cr1().write(|w| w.set_sse(true)); } } } impl<'d, T: Instance> Spi<'d, T, Blocking> { pub fn new_blocking( inner: impl Peripheral

+ 'd, clk: impl Peripheral

+ 'd> + 'd, mosi: impl Peripheral

+ 'd> + 'd, miso: impl Peripheral

+ 'd> + 'd, config: Config, ) -> Self { into_ref!(clk, mosi, miso); Self::new_inner( inner, Some(clk.map_into()), Some(mosi.map_into()), Some(miso.map_into()), None, None, None, config, ) } pub fn new_blocking_txonly( inner: impl Peripheral

+ 'd, clk: impl Peripheral

+ 'd> + 'd, mosi: impl Peripheral

+ 'd> + 'd, config: Config, ) -> Self { into_ref!(clk, mosi); Self::new_inner( inner, Some(clk.map_into()), Some(mosi.map_into()), None, None, None, None, config, ) } pub fn new_blocking_rxonly( inner: impl Peripheral

+ 'd, clk: impl Peripheral

+ 'd> + 'd, miso: impl Peripheral

+ 'd> + 'd, config: Config, ) -> Self { into_ref!(clk, miso); Self::new_inner( inner, Some(clk.map_into()), None, Some(miso.map_into()), None, None, None, config, ) } } impl<'d, T: Instance> Spi<'d, T, Async> { pub fn new( inner: impl Peripheral

+ 'd, clk: impl Peripheral

+ 'd> + 'd, mosi: impl Peripheral

+ 'd> + 'd, miso: impl Peripheral

+ 'd> + 'd, tx_dma: impl Peripheral

+ 'd, rx_dma: impl Peripheral

+ 'd, config: Config, ) -> Self { into_ref!(tx_dma, rx_dma, clk, mosi, miso); Self::new_inner( inner, Some(clk.map_into()), Some(mosi.map_into()), Some(miso.map_into()), None, Some(tx_dma.map_into()), Some(rx_dma.map_into()), config, ) } pub fn new_txonly( inner: impl Peripheral

+ 'd, clk: impl Peripheral

+ 'd> + 'd, mosi: impl Peripheral

+ 'd> + 'd, tx_dma: impl Peripheral

+ 'd, config: Config, ) -> Self { into_ref!(tx_dma, clk, mosi); Self::new_inner( inner, Some(clk.map_into()), Some(mosi.map_into()), None, None, Some(tx_dma.map_into()), None, config, ) } pub fn new_rxonly( inner: impl Peripheral

+ 'd, clk: impl Peripheral

+ 'd> + 'd, miso: impl Peripheral

+ 'd> + 'd, rx_dma: impl Peripheral

+ 'd, config: Config, ) -> Self { into_ref!(rx_dma, clk, miso); Self::new_inner( inner, Some(clk.map_into()), None, Some(miso.map_into()), None, None, Some(rx_dma.map_into()), config, ) } pub async fn write(&mut self, buffer: &[u8]) -> Result<(), Error> { let tx_ch = self.tx_dma.as_mut().unwrap(); let tx_transfer = unsafe { self.inner.regs().dmacr().modify(|reg| { reg.set_txdmae(true); }); // If we don't assign future to a variable, the data register pointer // is held across an await and makes the future non-Send. crate::dma::write(tx_ch, buffer, self.inner.regs().dr().ptr() as *mut _, T::TX_DREQ) }; tx_transfer.await; let p = self.inner.regs(); unsafe { while p.sr().read().bsy() {} // clear RX FIFO contents to prevent stale reads while p.sr().read().rne() { let _: u16 = p.dr().read().data(); } // clear RX overrun interrupt p.icr().write(|w| w.set_roric(true)); } Ok(()) } pub async fn read(&mut self, buffer: &mut [u8]) -> Result<(), Error> { unsafe { self.inner.regs().dmacr().write(|reg| { reg.set_rxdmae(true); reg.set_txdmae(true); }) }; let tx_ch = self.tx_dma.as_mut().unwrap(); let tx_transfer = unsafe { // If we don't assign future to a variable, the data register pointer // is held across an await and makes the future non-Send. crate::dma::write_repeated(tx_ch, self.inner.regs().dr().ptr() as *mut u8, buffer.len(), T::TX_DREQ) }; let rx_ch = self.rx_dma.as_mut().unwrap(); let rx_transfer = unsafe { // If we don't assign future to a variable, the data register pointer // is held across an await and makes the future non-Send. crate::dma::read(rx_ch, self.inner.regs().dr().ptr() as *const _, buffer, T::RX_DREQ) }; join(tx_transfer, rx_transfer).await; Ok(()) } pub async fn transfer(&mut self, rx_buffer: &mut [u8], tx_buffer: &[u8]) -> Result<(), Error> { self.transfer_inner(rx_buffer, tx_buffer).await } pub async fn transfer_in_place(&mut self, words: &mut [u8]) -> Result<(), Error> { self.transfer_inner(words, words).await } async fn transfer_inner(&mut self, rx_ptr: *mut [u8], tx_ptr: *const [u8]) -> Result<(), Error> { let (_, from_len) = crate::dma::slice_ptr_parts(tx_ptr); let (_, to_len) = crate::dma::slice_ptr_parts_mut(rx_ptr); assert_eq!(from_len, to_len); unsafe { self.inner.regs().dmacr().write(|reg| { reg.set_rxdmae(true); reg.set_txdmae(true); }) }; let tx_ch = self.tx_dma.as_mut().unwrap(); let tx_transfer = unsafe { // If we don't assign future to a variable, the data register pointer // is held across an await and makes the future non-Send. crate::dma::write(tx_ch, tx_ptr, self.inner.regs().dr().ptr() as *mut _, T::TX_DREQ) }; let rx_ch = self.rx_dma.as_mut().unwrap(); let rx_transfer = unsafe { // If we don't assign future to a variable, the data register pointer // is held across an await and makes the future non-Send. crate::dma::read(rx_ch, self.inner.regs().dr().ptr() as *const _, rx_ptr, T::RX_DREQ) }; join(tx_transfer, rx_transfer).await; Ok(()) } } mod sealed { use super::*; pub trait Mode {} pub trait Instance { const TX_DREQ: u8; const RX_DREQ: u8; fn regs(&self) -> pac::spi::Spi; } } pub trait Mode: sealed::Mode {} 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 = $rx_dreq; fn regs(&self) -> pac::spi::Spi { pac::$type } } impl Instance for peripherals::$type {} }; } impl_instance!(SPI0, Spi0, 16, 17); impl_instance!(SPI1, Spi1, 18, 19); pub trait ClkPin: GpioPin {} pub trait CsPin: GpioPin {} pub trait MosiPin: GpioPin {} pub trait MisoPin: GpioPin {} macro_rules! impl_pin { ($pin:ident, $instance:ident, $function:ident) => { impl $function for peripherals::$pin {} }; } impl_pin!(PIN_0, SPI0, MisoPin); impl_pin!(PIN_1, SPI0, CsPin); impl_pin!(PIN_2, SPI0, ClkPin); impl_pin!(PIN_3, SPI0, MosiPin); impl_pin!(PIN_4, SPI0, MisoPin); impl_pin!(PIN_5, SPI0, CsPin); impl_pin!(PIN_6, SPI0, ClkPin); impl_pin!(PIN_7, SPI0, MosiPin); impl_pin!(PIN_8, SPI1, MisoPin); impl_pin!(PIN_9, SPI1, CsPin); impl_pin!(PIN_10, SPI1, ClkPin); impl_pin!(PIN_11, SPI1, MosiPin); impl_pin!(PIN_12, SPI1, MisoPin); impl_pin!(PIN_13, SPI1, CsPin); impl_pin!(PIN_14, SPI1, ClkPin); impl_pin!(PIN_15, SPI1, MosiPin); impl_pin!(PIN_16, SPI0, MisoPin); impl_pin!(PIN_17, SPI0, CsPin); impl_pin!(PIN_18, SPI0, ClkPin); impl_pin!(PIN_19, SPI0, MosiPin); 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); // ==================== mod eh02 { use super::*; impl<'d, T: Instance, M: Mode> embedded_hal_02::blocking::spi::Transfer for Spi<'d, T, M> { type Error = Error; fn transfer<'w>(&mut self, words: &'w mut [u8]) -> Result<&'w [u8], Self::Error> { self.blocking_transfer_in_place(words)?; Ok(words) } } impl<'d, T: Instance, M: Mode> embedded_hal_02::blocking::spi::Write for Spi<'d, T, M> { type Error = Error; fn write(&mut self, words: &[u8]) -> Result<(), Self::Error> { self.blocking_write(words) } } } #[cfg(feature = "unstable-traits")] mod eh1 { use super::*; impl embedded_hal_1::spi::Error for Error { fn kind(&self) -> embedded_hal_1::spi::ErrorKind { match *self {} } } impl<'d, T: Instance, M: Mode> embedded_hal_1::spi::ErrorType for Spi<'d, T, M> { type Error = Error; } impl<'d, T: Instance, M: Mode> embedded_hal_1::spi::SpiBusFlush for Spi<'d, T, M> { fn flush(&mut self) -> Result<(), Self::Error> { Ok(()) } } impl<'d, T: Instance, M: Mode> embedded_hal_1::spi::SpiBusRead for Spi<'d, T, M> { fn read(&mut self, words: &mut [u8]) -> Result<(), Self::Error> { self.blocking_transfer(words, &[]) } } impl<'d, T: Instance, M: Mode> embedded_hal_1::spi::SpiBusWrite for Spi<'d, T, M> { fn write(&mut self, words: &[u8]) -> Result<(), Self::Error> { self.blocking_write(words) } } impl<'d, T: Instance, M: Mode> embedded_hal_1::spi::SpiBus for Spi<'d, T, M> { fn transfer(&mut self, read: &mut [u8], write: &[u8]) -> Result<(), Self::Error> { self.blocking_transfer(read, write) } fn transfer_in_place(&mut self, words: &mut [u8]) -> Result<(), Self::Error> { self.blocking_transfer_in_place(words) } } } #[cfg(all(feature = "unstable-traits", feature = "nightly"))] mod eha { use core::future::Future; use super::*; impl<'d, T: Instance> embedded_hal_async::spi::SpiBusFlush for Spi<'d, T, Async> { type FlushFuture<'a> = impl Future> + 'a where Self: 'a; fn flush<'a>(&'a mut self) -> Self::FlushFuture<'a> { async { Ok(()) } } } impl<'d, T: Instance> embedded_hal_async::spi::SpiBusWrite for Spi<'d, T, Async> { type WriteFuture<'a> = impl Future> + 'a where Self: 'a; fn write<'a>(&'a mut self, data: &'a [u8]) -> Self::WriteFuture<'a> { self.write(data) } } impl<'d, T: Instance> embedded_hal_async::spi::SpiBusRead for Spi<'d, T, Async> { type ReadFuture<'a> = impl Future> + 'a where Self: 'a; fn read<'a>(&'a mut self, data: &'a mut [u8]) -> Self::ReadFuture<'a> { self.read(data) } } impl<'d, T: Instance> embedded_hal_async::spi::SpiBus for Spi<'d, T, Async> { type TransferFuture<'a> = impl Future> + 'a where Self: 'a; fn transfer<'a>(&'a mut self, rx: &'a mut [u8], tx: &'a [u8]) -> Self::TransferFuture<'a> { self.transfer(rx, tx) } type TransferInPlaceFuture<'a> = impl Future> + 'a where Self: 'a; fn transfer_in_place<'a>(&'a mut self, words: &'a mut [u8]) -> Self::TransferInPlaceFuture<'a> { self.transfer_in_place(words) } } } impl<'d, T: Instance, M: Mode> SetConfig for Spi<'d, T, M> { type Config = Config; fn set_config(&mut self, config: &Self::Config) { let p = self.inner.regs(); let (presc, postdiv) = calc_prescs(config.frequency); unsafe { p.cpsr().write(|w| w.set_cpsdvsr(presc)); p.cr0().write(|w| { w.set_dss(0b0111); // 8bit w.set_spo(config.polarity == Polarity::IdleHigh); w.set_sph(config.phase == Phase::CaptureOnSecondTransition); w.set_scr(postdiv); }); } } }