embassy/embassy-nrf/src/spim.rs

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#![macro_use]
use core::marker::PhantomData;
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use core::sync::atomic::{compiler_fence, Ordering};
use core::task::Poll;
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use embassy_embedded_hal::SetConfig;
use embassy_hal_common::{into_ref, PeripheralRef};
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pub use embedded_hal_02::spi::{Mode, Phase, Polarity, MODE_0, MODE_1, MODE_2, MODE_3};
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use futures::future::poll_fn;
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pub use pac::spim0::frequency::FREQUENCY_A as Frequency;
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use crate::chip::FORCE_COPY_BUFFER_SIZE;
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use crate::gpio::sealed::Pin as _;
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use crate::gpio::{self, AnyPin, Pin as GpioPin, PselBits};
use crate::interrupt::{Interrupt, InterruptExt};
use crate::util::{slice_in_ram_or, slice_ptr_parts, slice_ptr_parts_mut};
use crate::{pac, Peripheral};
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#[derive(Debug, Clone, Copy, PartialEq, Eq)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
#[non_exhaustive]
pub enum Error {
TxBufferTooLong,
RxBufferTooLong,
/// EasyDMA can only read from data memory, read only buffers in flash will fail.
DMABufferNotInDataMemory,
}
/// Interface for the SPIM peripheral using EasyDMA to offload the transmission and reception workload.
///
/// For more details about EasyDMA, consult the module documentation.
pub struct Spim<'d, T: Instance> {
phantom: PhantomData<&'d mut T>,
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}
#[non_exhaustive]
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pub struct Config {
pub frequency: Frequency,
pub mode: Mode,
pub orc: u8,
}
impl Default for Config {
fn default() -> Self {
Self {
frequency: Frequency::M1,
mode: MODE_0,
orc: 0x00,
}
}
}
impl<'d, T: Instance> Spim<'d, T> {
pub fn new(
spim: impl Peripheral<P = T> + 'd,
irq: impl Peripheral<P = T::Interrupt> + 'd,
sck: impl Peripheral<P = impl GpioPin> + 'd,
miso: impl Peripheral<P = impl GpioPin> + 'd,
mosi: impl Peripheral<P = impl GpioPin> + 'd,
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config: Config,
) -> Self {
into_degraded_ref!(sck, miso, mosi);
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Self::new_inner(spim, irq, sck, Some(miso), Some(mosi), config)
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}
pub fn new_txonly(
spim: impl Peripheral<P = T> + 'd,
irq: impl Peripheral<P = T::Interrupt> + 'd,
sck: impl Peripheral<P = impl GpioPin> + 'd,
mosi: impl Peripheral<P = impl GpioPin> + 'd,
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config: Config,
) -> Self {
into_degraded_ref!(sck, mosi);
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Self::new_inner(spim, irq, sck, None, Some(mosi), config)
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}
pub fn new_rxonly(
spim: impl Peripheral<P = T> + 'd,
irq: impl Peripheral<P = T::Interrupt> + 'd,
sck: impl Peripheral<P = impl GpioPin> + 'd,
miso: impl Peripheral<P = impl GpioPin> + 'd,
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config: Config,
) -> Self {
into_degraded_ref!(sck, miso);
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Self::new_inner(spim, irq, sck, Some(miso), None, config)
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}
fn new_inner(
_spim: impl Peripheral<P = T> + 'd,
irq: impl Peripheral<P = T::Interrupt> + 'd,
sck: PeripheralRef<'d, AnyPin>,
miso: Option<PeripheralRef<'d, AnyPin>>,
mosi: Option<PeripheralRef<'d, AnyPin>>,
config: Config,
) -> Self {
into_ref!(irq);
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let r = T::regs();
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// Configure pins
sck.conf().write(|w| w.dir().output().drive().h0h1());
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if let Some(mosi) = &mosi {
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mosi.conf().write(|w| w.dir().output().drive().h0h1());
}
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if let Some(miso) = &miso {
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miso.conf().write(|w| w.input().connect().drive().h0h1());
}
match config.mode.polarity {
Polarity::IdleHigh => {
sck.set_high();
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if let Some(mosi) = &mosi {
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mosi.set_high();
}
}
Polarity::IdleLow => {
sck.set_low();
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if let Some(mosi) = &mosi {
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mosi.set_low();
}
}
}
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// Select pins.
r.psel.sck.write(|w| unsafe { w.bits(sck.psel_bits()) });
r.psel.mosi.write(|w| unsafe { w.bits(mosi.psel_bits()) });
r.psel.miso.write(|w| unsafe { w.bits(miso.psel_bits()) });
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// Enable SPIM instance.
r.enable.write(|w| w.enable().enabled());
// Configure mode.
let mode = config.mode;
r.config.write(|w| {
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match mode {
MODE_0 => {
w.order().msb_first();
w.cpol().active_high();
w.cpha().leading();
}
MODE_1 => {
w.order().msb_first();
w.cpol().active_high();
w.cpha().trailing();
}
MODE_2 => {
w.order().msb_first();
w.cpol().active_low();
w.cpha().leading();
}
MODE_3 => {
w.order().msb_first();
w.cpol().active_low();
w.cpha().trailing();
}
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}
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w
});
// Configure frequency.
let frequency = config.frequency;
r.frequency.write(|w| w.frequency().variant(frequency));
// Set over-read character
let orc = config.orc;
r.orc.write(|w| unsafe { w.orc().bits(orc) });
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// Disable all events interrupts
r.intenclr.write(|w| unsafe { w.bits(0xFFFF_FFFF) });
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irq.set_handler(Self::on_interrupt);
irq.unpend();
irq.enable();
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Self { phantom: PhantomData }
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}
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fn on_interrupt(_: *mut ()) {
let r = T::regs();
let s = T::state();
if r.events_end.read().bits() != 0 {
s.end_waker.wake();
r.intenclr.write(|w| w.end().clear());
}
}
fn prepare(&mut self, rx: *mut [u8], tx: *const [u8]) -> Result<(), Error> {
slice_in_ram_or(tx, Error::DMABufferNotInDataMemory)?;
// NOTE: RAM slice check for rx is not necessary, as a mutable
// slice can only be built from data located in RAM.
compiler_fence(Ordering::SeqCst);
let r = T::regs();
// Set up the DMA write.
let (ptr, len) = slice_ptr_parts(tx);
r.txd.ptr.write(|w| unsafe { w.ptr().bits(ptr as _) });
r.txd.maxcnt.write(|w| unsafe { w.maxcnt().bits(len as _) });
// Set up the DMA read.
let (ptr, len) = slice_ptr_parts_mut(rx);
r.rxd.ptr.write(|w| unsafe { w.ptr().bits(ptr as _) });
r.rxd.maxcnt.write(|w| unsafe { w.maxcnt().bits(len as _) });
// Reset and enable the event
r.events_end.reset();
r.intenset.write(|w| w.end().set());
// Start SPI transaction.
r.tasks_start.write(|w| unsafe { w.bits(1) });
Ok(())
}
fn blocking_inner_from_ram(&mut self, rx: *mut [u8], tx: *const [u8]) -> Result<(), Error> {
self.prepare(rx, tx)?;
// Wait for 'end' event.
while T::regs().events_end.read().bits() == 0 {}
compiler_fence(Ordering::SeqCst);
Ok(())
}
fn blocking_inner(&mut self, rx: &mut [u8], tx: &[u8]) -> Result<(), Error> {
match self.blocking_inner_from_ram(rx, tx) {
Ok(_) => Ok(()),
Err(Error::DMABufferNotInDataMemory) => {
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trace!("Copying SPIM tx buffer into RAM for DMA");
let tx_ram_buf = &mut [0; FORCE_COPY_BUFFER_SIZE][..tx.len()];
tx_ram_buf.copy_from_slice(tx);
self.blocking_inner_from_ram(rx, tx_ram_buf)
}
Err(error) => Err(error),
}
}
async fn async_inner_from_ram(&mut self, rx: *mut [u8], tx: *const [u8]) -> Result<(), Error> {
self.prepare(rx, tx)?;
// Wait for 'end' event.
poll_fn(|cx| {
T::state().end_waker.register(cx.waker());
if T::regs().events_end.read().bits() != 0 {
return Poll::Ready(());
}
Poll::Pending
})
.await;
compiler_fence(Ordering::SeqCst);
Ok(())
}
async fn async_inner(&mut self, rx: &mut [u8], tx: &[u8]) -> Result<(), Error> {
match self.async_inner_from_ram(rx, tx).await {
Ok(_) => Ok(()),
Err(Error::DMABufferNotInDataMemory) => {
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trace!("Copying SPIM tx buffer into RAM for DMA");
let tx_ram_buf = &mut [0; FORCE_COPY_BUFFER_SIZE][..tx.len()];
tx_ram_buf.copy_from_slice(tx);
self.async_inner_from_ram(rx, tx_ram_buf).await
}
Err(error) => Err(error),
}
}
/// Reads data from the SPI bus without sending anything. Blocks until the buffer has been filled.
pub fn blocking_read(&mut self, data: &mut [u8]) -> Result<(), Error> {
self.blocking_inner(data, &[])
}
/// Simultaneously sends and receives data. Blocks until the transmission is completed.
/// If necessary, the write buffer will be copied into RAM (see struct description for detail).
pub fn blocking_transfer(&mut self, read: &mut [u8], write: &[u8]) -> Result<(), Error> {
self.blocking_inner(read, write)
}
/// Same as [`blocking_transfer`](Spim::blocking_transfer) but will fail instead of copying data into RAM. Consult the module level documentation to learn more.
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pub fn blocking_transfer_from_ram(&mut self, read: &mut [u8], write: &[u8]) -> Result<(), Error> {
self.blocking_inner(read, write)
}
/// Simultaneously sends and receives data.
/// Places the received data into the same buffer and blocks until the transmission is completed.
pub fn blocking_transfer_in_place(&mut self, data: &mut [u8]) -> Result<(), Error> {
self.blocking_inner_from_ram(data, data)
}
/// Sends data, discarding any received data. Blocks until the transmission is completed.
/// If necessary, the write buffer will be copied into RAM (see struct description for detail).
pub fn blocking_write(&mut self, data: &[u8]) -> Result<(), Error> {
self.blocking_inner(&mut [], data)
}
/// Same as [`blocking_write`](Spim::blocking_write) but will fail instead of copying data into RAM. Consult the module level documentation to learn more.
pub fn blocking_write_from_ram(&mut self, data: &[u8]) -> Result<(), Error> {
self.blocking_inner(&mut [], data)
}
/// Reads data from the SPI bus without sending anything.
pub async fn read(&mut self, data: &mut [u8]) -> Result<(), Error> {
self.async_inner(data, &[]).await
}
/// Simultaneously sends and receives data.
/// If necessary, the write buffer will be copied into RAM (see struct description for detail).
pub async fn transfer(&mut self, read: &mut [u8], write: &[u8]) -> Result<(), Error> {
self.async_inner(read, write).await
}
/// Same as [`transfer`](Spim::transfer) but will fail instead of copying data into RAM. Consult the module level documentation to learn more.
pub async fn transfer_from_ram(&mut self, read: &mut [u8], write: &[u8]) -> Result<(), Error> {
self.async_inner_from_ram(read, write).await
}
/// Simultaneously sends and receives data. Places the received data into the same buffer.
pub async fn transfer_in_place(&mut self, data: &mut [u8]) -> Result<(), Error> {
self.async_inner_from_ram(data, data).await
}
/// Sends data, discarding any received data.
/// If necessary, the write buffer will be copied into RAM (see struct description for detail).
pub async fn write(&mut self, data: &[u8]) -> Result<(), Error> {
self.async_inner(&mut [], data).await
}
/// Same as [`write`](Spim::write) but will fail instead of copying data into RAM. Consult the module level documentation to learn more.
pub async fn write_from_ram(&mut self, data: &[u8]) -> Result<(), Error> {
self.async_inner_from_ram(&mut [], data).await
}
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}
impl<'d, T: Instance> Drop for Spim<'d, T> {
fn drop(&mut self) {
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trace!("spim drop");
// TODO check for abort, wait for xxxstopped
// disable!
let r = T::regs();
r.enable.write(|w| w.enable().disabled());
gpio::deconfigure_pin(r.psel.sck.read().bits());
gpio::deconfigure_pin(r.psel.miso.read().bits());
gpio::deconfigure_pin(r.psel.mosi.read().bits());
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trace!("spim drop: done");
}
}
pub(crate) mod sealed {
use embassy::waitqueue::AtomicWaker;
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use super::*;
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pub struct State {
pub end_waker: AtomicWaker,
}
impl State {
pub const fn new() -> Self {
Self {
end_waker: AtomicWaker::new(),
}
}
}
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pub trait Instance {
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fn regs() -> &'static pac::spim0::RegisterBlock;
fn state() -> &'static State;
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}
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}
pub trait Instance: Peripheral<P = Self> + sealed::Instance + 'static {
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type Interrupt: Interrupt;
}
macro_rules! impl_spim {
($type:ident, $pac_type:ident, $irq:ident) => {
impl crate::spim::sealed::Instance for peripherals::$type {
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fn regs() -> &'static pac::spim0::RegisterBlock {
unsafe { &*pac::$pac_type::ptr() }
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}
fn state() -> &'static crate::spim::sealed::State {
static STATE: crate::spim::sealed::State = crate::spim::sealed::State::new();
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&STATE
}
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}
impl crate::spim::Instance for peripherals::$type {
type Interrupt = crate::interrupt::$irq;
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}
};
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}
// ====================
mod eh02 {
use super::*;
impl<'d, T: Instance> embedded_hal_02::blocking::spi::Transfer<u8> for Spim<'d, T> {
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> embedded_hal_02::blocking::spi::Write<u8> for Spim<'d, T> {
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 {
Self::TxBufferTooLong => embedded_hal_1::spi::ErrorKind::Other,
Self::RxBufferTooLong => embedded_hal_1::spi::ErrorKind::Other,
Self::DMABufferNotInDataMemory => embedded_hal_1::spi::ErrorKind::Other,
}
}
}
impl<'d, T: Instance> embedded_hal_1::spi::ErrorType for Spim<'d, T> {
type Error = Error;
}
impl<'d, T: Instance> embedded_hal_1::spi::blocking::SpiBusFlush for Spim<'d, T> {
fn flush(&mut self) -> Result<(), Self::Error> {
Ok(())
}
}
impl<'d, T: Instance> embedded_hal_1::spi::blocking::SpiBusRead<u8> for Spim<'d, T> {
fn read(&mut self, words: &mut [u8]) -> Result<(), Self::Error> {
self.blocking_transfer(words, &[])
}
}
impl<'d, T: Instance> embedded_hal_1::spi::blocking::SpiBusWrite<u8> for Spim<'d, T> {
fn write(&mut self, words: &[u8]) -> Result<(), Self::Error> {
self.blocking_write(words)
}
}
impl<'d, T: Instance> embedded_hal_1::spi::blocking::SpiBus<u8> for Spim<'d, T> {
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_if::cfg_if! {
if #[cfg(all(feature = "unstable-traits", feature = "nightly"))] {
use core::future::Future;
impl<'d, T: Instance> embedded_hal_async::spi::SpiBusFlush for Spim<'d, T> {
type FlushFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a;
fn flush<'a>(&'a mut self) -> Self::FlushFuture<'a> {
async move { Ok(()) }
}
}
impl<'d, T: Instance> embedded_hal_async::spi::SpiBusRead<u8> for Spim<'d, T> {
type ReadFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a;
fn read<'a>(&'a mut self, words: &'a mut [u8]) -> Self::ReadFuture<'a> {
self.read(words)
}
}
impl<'d, T: Instance> embedded_hal_async::spi::SpiBusWrite<u8> for Spim<'d, T> {
type WriteFuture<'a> = impl Future<Output = Result<(), Self::Error>> + '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::SpiBus<u8> for Spim<'d, T> {
type TransferFuture<'a> = impl Future<Output = Result<(), Self::Error>> + '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<Output = Result<(), Self::Error>> + 'a where Self: 'a;
fn transfer_in_place<'a>(
&'a mut self,
words: &'a mut [u8],
) -> Self::TransferInPlaceFuture<'a> {
self.transfer_in_place(words)
}
}
}
}
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impl<'d, T: Instance> SetConfig for Spim<'d, T> {
type Config = Config;
fn set_config(&mut self, config: &Self::Config) {
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let r = T::regs();
// Configure mode.
let mode = config.mode;
r.config.write(|w| {
match mode {
MODE_0 => {
w.order().msb_first();
w.cpol().active_high();
w.cpha().leading();
}
MODE_1 => {
w.order().msb_first();
w.cpol().active_high();
w.cpha().trailing();
}
MODE_2 => {
w.order().msb_first();
w.cpol().active_low();
w.cpha().leading();
}
MODE_3 => {
w.order().msb_first();
w.cpol().active_low();
w.cpha().trailing();
}
}
w
});
// Configure frequency.
let frequency = config.frequency;
r.frequency.write(|w| w.frequency().variant(frequency));
// Set over-read character
let orc = config.orc;
r.orc.write(|w| unsafe { w.orc().bits(orc) });
}
}