embassy/embassy-stm32/src/spi/v1.rs
2021-10-11 23:33:32 +02:00

487 lines
13 KiB
Rust

#![macro_use]
use crate::dma::NoDma;
use crate::gpio::sealed::AFType;
use crate::gpio::sealed::Pin;
use crate::gpio::{AnyPin, NoPin};
use crate::pac::spi;
use crate::peripherals;
use crate::spi::{
ByteOrder, Config, Error, Instance, MisoPin, MosiPin, RxDmaChannel, SckPin, TxDmaChannel,
WordSize,
};
use crate::time::Hertz;
use core::future::Future;
use core::marker::PhantomData;
use core::ptr;
use embassy::util::Unborrow;
use embassy_hal_common::unborrow;
use embassy_traits::spi as traits;
pub use embedded_hal::blocking;
pub use embedded_hal::spi::{Mode, Phase, Polarity, MODE_0, MODE_1, MODE_2, MODE_3};
use futures::future::join3;
impl WordSize {
fn dff(&self) -> spi::vals::Dff {
match self {
WordSize::EightBit => spi::vals::Dff::EIGHTBIT,
WordSize::SixteenBit => spi::vals::Dff::SIXTEENBIT,
}
}
}
macro_rules! impl_nopin {
($inst:ident, $signal:ident) => {
impl $signal<peripherals::$inst> for NoPin {}
impl super::sealed::$signal<peripherals::$inst> for NoPin {
fn af_num(&self) -> u8 {
0
}
}
};
}
crate::pac::peripherals!(
(spi, $inst:ident) => {
impl_nopin!($inst, SckPin);
impl_nopin!($inst, MosiPin);
impl_nopin!($inst, MisoPin);
};
);
pub struct Spi<'d, T: Instance, Tx, Rx> {
sck: Option<AnyPin>,
mosi: Option<AnyPin>,
miso: Option<AnyPin>,
txdma: Tx,
rxdma: Rx,
current_word_size: WordSize,
phantom: PhantomData<&'d mut T>,
}
impl<'d, T: Instance, Tx, Rx> Spi<'d, T, Tx, Rx> {
pub fn new<F>(
_peri: impl Unborrow<Target = T> + 'd,
sck: impl Unborrow<Target = impl SckPin<T>>,
mosi: impl Unborrow<Target = impl MosiPin<T>>,
miso: impl Unborrow<Target = impl MisoPin<T>>,
txdma: impl Unborrow<Target = Tx>,
rxdma: impl Unborrow<Target = Rx>,
freq: F,
config: Config,
) -> Self
where
F: Into<Hertz>,
{
unborrow!(sck, mosi, miso, txdma, rxdma);
let sck_af = sck.af_num();
let mosi_af = mosi.af_num();
let miso_af = miso.af_num();
let sck = sck.degrade_optional();
let mosi = mosi.degrade_optional();
let miso = miso.degrade_optional();
unsafe {
sck.as_ref()
.map(|x| x.set_as_af(sck_af, AFType::OutputPushPull));
mosi.as_ref()
.map(|x| x.set_as_af(mosi_af, AFType::OutputPushPull));
miso.as_ref().map(|x| x.set_as_af(miso_af, AFType::Input));
}
unsafe {
T::regs().cr2().modify(|w| {
w.set_ssoe(false);
});
}
let pclk = T::frequency();
let br = Self::compute_baud_rate(pclk, freq.into());
unsafe {
T::enable();
T::reset();
T::regs().cr1().modify(|w| {
w.set_cpha(
match config.mode.phase == Phase::CaptureOnSecondTransition {
true => spi::vals::Cpha::SECONDEDGE,
false => spi::vals::Cpha::FIRSTEDGE,
},
);
w.set_cpol(match config.mode.polarity == Polarity::IdleHigh {
true => spi::vals::Cpol::IDLEHIGH,
false => spi::vals::Cpol::IDLELOW,
});
w.set_mstr(spi::vals::Mstr::MASTER);
w.set_br(spi::vals::Br(br));
w.set_spe(true);
w.set_lsbfirst(match config.byte_order {
ByteOrder::LsbFirst => spi::vals::Lsbfirst::LSBFIRST,
ByteOrder::MsbFirst => spi::vals::Lsbfirst::MSBFIRST,
});
w.set_ssi(true);
w.set_ssm(true);
w.set_crcen(false);
w.set_bidimode(spi::vals::Bidimode::UNIDIRECTIONAL);
if mosi.is_none() {
w.set_rxonly(spi::vals::Rxonly::OUTPUTDISABLED);
}
w.set_dff(WordSize::EightBit.dff())
});
}
Self {
sck,
mosi,
miso,
txdma,
rxdma,
current_word_size: WordSize::EightBit,
phantom: PhantomData,
}
}
fn compute_baud_rate(clocks: Hertz, freq: Hertz) -> u8 {
match clocks.0 / freq.0 {
0 => unreachable!(),
1..=2 => 0b000,
3..=5 => 0b001,
6..=11 => 0b010,
12..=23 => 0b011,
24..=39 => 0b100,
40..=95 => 0b101,
96..=191 => 0b110,
_ => 0b111,
}
}
fn set_word_size(&mut self, word_size: WordSize) {
if self.current_word_size == word_size {
return;
}
unsafe {
T::regs().cr1().modify(|reg| {
reg.set_spe(false);
reg.set_dff(word_size.dff())
});
T::regs().cr1().modify(|reg| {
reg.set_spe(true);
});
self.current_word_size = word_size;
}
}
#[allow(unused)]
async fn write_dma_u8(&mut self, write: &[u8]) -> Result<(), Error>
where
Tx: TxDmaChannel<T>,
{
unsafe {
T::regs().cr1().modify(|w| {
w.set_spe(false);
});
}
self.set_word_size(WordSize::EightBit);
let request = self.txdma.request();
let dst = T::regs().dr().ptr() as *mut u8;
let f = self.txdma.write(request, write, dst);
unsafe {
T::regs().cr2().modify(|reg| {
reg.set_txdmaen(true);
});
T::regs().cr1().modify(|w| {
w.set_spe(true);
});
}
f.await;
Ok(())
}
#[allow(unused)]
async fn read_dma_u8(&mut self, read: &mut [u8]) -> Result<(), Error>
where
Tx: TxDmaChannel<T>,
Rx: RxDmaChannel<T>,
{
unsafe {
T::regs().cr1().modify(|w| {
w.set_spe(false);
});
T::regs().cr2().modify(|reg| {
reg.set_rxdmaen(true);
});
}
self.set_word_size(WordSize::EightBit);
let clock_byte_count = read.len();
let rx_request = self.rxdma.request();
let rx_src = T::regs().dr().ptr() as *mut u8;
let rx_f = self.rxdma.read(rx_request, rx_src, read);
let tx_request = self.txdma.request();
let tx_dst = T::regs().dr().ptr() as *mut u8;
let clock_byte = 0x00;
let tx_f = self
.txdma
.write_x(tx_request, &clock_byte, clock_byte_count, tx_dst);
unsafe {
T::regs().cr2().modify(|reg| {
reg.set_txdmaen(true);
});
T::regs().cr1().modify(|w| {
w.set_spe(true);
});
}
join3(tx_f, rx_f, Self::wait_for_idle()).await;
unsafe {
T::regs().cr2().modify(|reg| {
reg.set_txdmaen(false);
reg.set_rxdmaen(false);
});
T::regs().cr1().modify(|w| {
w.set_spe(false);
});
}
Ok(())
}
#[allow(unused)]
async fn read_write_dma_u8(&mut self, read: &mut [u8], write: &[u8]) -> Result<(), Error>
where
Tx: TxDmaChannel<T>,
Rx: RxDmaChannel<T>,
{
assert!(read.len() >= write.len());
unsafe {
T::regs().cr1().modify(|w| {
w.set_spe(false);
});
T::regs().cr2().modify(|reg| {
reg.set_rxdmaen(true);
});
}
self.set_word_size(WordSize::EightBit);
let rx_request = self.rxdma.request();
let rx_src = T::regs().dr().ptr() as *mut u8;
let rx_f = self
.rxdma
.read(rx_request, rx_src, &mut read[0..write.len()]);
let tx_request = self.txdma.request();
let tx_dst = T::regs().dr().ptr() as *mut u8;
let tx_f = self.txdma.write(tx_request, write, tx_dst);
unsafe {
T::regs().cr2().modify(|reg| {
reg.set_txdmaen(true);
});
T::regs().cr1().modify(|w| {
w.set_spe(true);
});
}
join3(tx_f, rx_f, Self::wait_for_idle()).await;
unsafe {
T::regs().cr2().modify(|reg| {
reg.set_txdmaen(false);
reg.set_rxdmaen(false);
});
T::regs().cr1().modify(|w| {
w.set_spe(false);
});
}
Ok(())
}
async fn wait_for_idle() {
unsafe {
while T::regs().sr().read().bsy() {
// spin
}
}
}
}
impl<'d, T: Instance, Tx, Rx> Drop for Spi<'d, T, Tx, Rx> {
fn drop(&mut self) {
unsafe {
self.sck.as_ref().map(|x| x.set_as_analog());
self.mosi.as_ref().map(|x| x.set_as_analog());
self.miso.as_ref().map(|x| x.set_as_analog());
}
}
}
impl<'d, T: Instance> embedded_hal::blocking::spi::Write<u8> for Spi<'d, T, NoDma, NoDma> {
type Error = Error;
fn write(&mut self, words: &[u8]) -> Result<(), Self::Error> {
self.set_word_size(WordSize::EightBit);
let regs = T::regs();
for word in words.iter() {
write_word(regs, *word)?;
let _: u8 = read_word(regs)?;
}
Ok(())
}
}
impl<'d, T: Instance> embedded_hal::blocking::spi::Transfer<u8> for Spi<'d, T, NoDma, NoDma> {
type Error = Error;
fn transfer<'w>(&mut self, words: &'w mut [u8]) -> Result<&'w [u8], Self::Error> {
self.set_word_size(WordSize::EightBit);
let regs = T::regs();
for word in words.iter_mut() {
write_word(regs, *word)?;
*word = read_word(regs)?;
}
Ok(words)
}
}
impl<'d, T: Instance> embedded_hal::blocking::spi::Write<u16> for Spi<'d, T, NoDma, NoDma> {
type Error = Error;
fn write(&mut self, words: &[u16]) -> Result<(), Self::Error> {
self.set_word_size(WordSize::SixteenBit);
let regs = T::regs();
for word in words.iter() {
write_word(regs, *word)?;
let _: u8 = read_word(regs)?;
}
Ok(())
}
}
impl<'d, T: Instance> embedded_hal::blocking::spi::Transfer<u16> for Spi<'d, T, NoDma, NoDma> {
type Error = Error;
fn transfer<'w>(&mut self, words: &'w mut [u16]) -> Result<&'w [u16], Self::Error> {
self.set_word_size(WordSize::SixteenBit);
let regs = T::regs();
for word in words.iter_mut() {
write_word(regs, *word)?;
*word = read_word(regs)?;
}
Ok(words)
}
}
impl<'d, T: Instance, Tx, Rx> traits::Spi<u8> for Spi<'d, T, Tx, Rx> {
type Error = super::Error;
}
impl<'d, T: Instance, Tx: TxDmaChannel<T>, Rx> traits::Write<u8> for Spi<'d, T, Tx, Rx> {
#[rustfmt::skip]
type WriteFuture<'a> where Self: 'a = impl Future<Output = Result<(), Self::Error>> + 'a;
fn write<'a>(&'a mut self, data: &'a [u8]) -> Self::WriteFuture<'a> {
self.write_dma_u8(data)
}
}
impl<'d, T: Instance, Tx: TxDmaChannel<T>, Rx: RxDmaChannel<T>> traits::Read<u8>
for Spi<'d, T, Tx, Rx>
{
#[rustfmt::skip]
type ReadFuture<'a> where Self: 'a = impl Future<Output = Result<(), Self::Error>> + 'a;
fn read<'a>(&'a mut self, data: &'a mut [u8]) -> Self::ReadFuture<'a> {
self.read_dma_u8(data)
}
}
impl<'d, T: Instance, Tx: TxDmaChannel<T>, Rx: RxDmaChannel<T>> traits::FullDuplex<u8>
for Spi<'d, T, Tx, Rx>
{
#[rustfmt::skip]
type WriteReadFuture<'a> where Self: 'a = impl Future<Output=Result<(), Self::Error>> + 'a;
fn read_write<'a>(
&'a mut self,
read: &'a mut [u8],
write: &'a [u8],
) -> Self::WriteReadFuture<'a> {
self.read_write_dma_u8(read, write)
}
}
trait Word {}
impl Word for u8 {}
impl Word for u16 {}
fn write_word<W: Word>(regs: &'static crate::pac::spi::Spi, word: W) -> Result<(), Error> {
loop {
let sr = unsafe { regs.sr().read() };
if sr.ovr() {
return Err(Error::Overrun);
}
#[cfg(not(spi_f1))]
if sr.fre() {
return Err(Error::Framing);
}
if sr.modf() {
return Err(Error::ModeFault);
}
if sr.crcerr() {
return Err(Error::Crc);
}
if sr.txe() {
unsafe {
let dr = regs.dr().ptr() as *mut W;
ptr::write_volatile(dr, word);
}
return Ok(());
}
}
}
/// Read a single word blocking. Assumes word size have already been set.
fn read_word<W: Word>(regs: &'static crate::pac::spi::Spi) -> Result<W, Error> {
loop {
let sr = unsafe { regs.sr().read() };
if sr.ovr() {
return Err(Error::Overrun);
}
#[cfg(not(spi_f1))]
if sr.fre() {
return Err(Error::Framing);
}
if sr.modf() {
return Err(Error::ModeFault);
}
if sr.crcerr() {
return Err(Error::Crc);
}
if sr.rxne() {
unsafe {
let dr = regs.dr().ptr() as *const W;
return Ok(ptr::read_volatile(dr));
}
}
}
}