embassy/embassy-rp/src/dma.rs
Lachezar Lechev 7a4db1da26
fix(rp): spi transfer
Signed-off-by: Lachezar Lechev <elpiel93@gmail.com>
2023-03-20 16:34:30 +02:00

296 lines
7.0 KiB
Rust

//! Direct Memory Access (DMA)
use core::future::Future;
use core::pin::Pin;
use core::sync::atomic::{compiler_fence, Ordering};
use core::task::{Context, Poll};
use embassy_cortex_m::interrupt::{Interrupt, InterruptExt};
use embassy_hal_common::{impl_peripheral, into_ref, Peripheral, PeripheralRef};
use embassy_sync::waitqueue::AtomicWaker;
use pac::dma::vals::DataSize;
use crate::pac::dma::vals;
use crate::{interrupt, pac, peripherals};
#[interrupt]
unsafe fn DMA_IRQ_0() {
let ints0 = pac::DMA.ints0().read().ints0();
for channel in 0..CHANNEL_COUNT {
let ctrl_trig = pac::DMA.ch(channel).ctrl_trig().read();
if ctrl_trig.ahb_error() {
panic!("DMA: error on DMA_0 channel {}", channel);
}
if ints0 & (1 << channel) == (1 << channel) {
CHANNEL_WAKERS[channel].wake();
}
}
pac::DMA.ints0().write(|w| w.set_ints0(ints0));
}
pub(crate) unsafe fn init() {
let irq = interrupt::DMA_IRQ_0::steal();
irq.disable();
irq.set_priority(interrupt::Priority::P3);
pac::DMA.inte0().write(|w| w.set_inte0(0xFFFF));
irq.enable();
}
pub unsafe fn read<'a, C: Channel, W: Word>(
ch: impl Peripheral<P = C> + 'a,
from: *const W,
to: *mut [W],
dreq: u8,
) -> Transfer<'a, C> {
let (to_ptr, len) = crate::dma::slice_ptr_parts(to);
copy_inner(
ch,
from as *const u32,
to_ptr as *mut u32,
len,
W::size(),
false,
true,
dreq,
)
}
pub unsafe fn write<'a, C: Channel, W: Word>(
ch: impl Peripheral<P = C> + 'a,
from: *const [W],
to: *mut W,
dreq: u8,
) -> Transfer<'a, C> {
let (from_ptr, len) = crate::dma::slice_ptr_parts(from);
copy_inner(
ch,
from_ptr as *const u32,
to as *mut u32,
len,
W::size(),
true,
false,
dreq,
)
}
pub unsafe fn write_repeated<'a, C: Channel, W: Word>(
ch: impl Peripheral<P = C> + 'a,
to: *mut W,
len: usize,
dreq: u8,
) -> Transfer<'a, C> {
let dummy: u32 = 0;
copy_inner(
ch,
&dummy as *const u32,
to as *mut u32,
len,
W::size(),
false,
false,
dreq,
)
}
pub unsafe fn copy<'a, C: Channel, W: Word>(
ch: impl Peripheral<P = C> + 'a,
from: &[W],
to: &mut [W],
) -> Transfer<'a, C> {
let (from_ptr, from_len) = crate::dma::slice_ptr_parts(from);
let (to_ptr, to_len) = crate::dma::slice_ptr_parts_mut(to);
assert_eq!(from_len, to_len);
copy_inner(
ch,
from_ptr as *const u32,
to_ptr as *mut u32,
from_len,
W::size(),
true,
true,
vals::TreqSel::PERMANENT.0,
)
}
fn copy_inner<'a, C: Channel>(
ch: impl Peripheral<P = C> + 'a,
from: *const u32,
to: *mut u32,
len: usize,
data_size: DataSize,
incr_read: bool,
incr_write: bool,
dreq: u8,
) -> Transfer<'a, C> {
into_ref!(ch);
unsafe {
let p = ch.regs();
p.read_addr().write_value(from as u32);
p.write_addr().write_value(to as u32);
p.trans_count().write_value(len as u32);
compiler_fence(Ordering::SeqCst);
p.ctrl_trig().write(|w| {
// TODO: Add all DREQ options to pac vals::TreqSel, and use
// `set_treq:sel`
w.0 = ((dreq as u32) & 0x3f) << 15usize;
w.set_data_size(data_size);
w.set_incr_read(incr_read);
w.set_incr_write(incr_write);
w.set_chain_to(ch.number());
w.set_en(true);
});
compiler_fence(Ordering::SeqCst);
}
Transfer::new(ch)
}
#[must_use = "futures do nothing unless you `.await` or poll them"]
pub struct Transfer<'a, C: Channel> {
channel: PeripheralRef<'a, C>,
}
impl<'a, C: Channel> Transfer<'a, C> {
pub(crate) fn new(channel: impl Peripheral<P = C> + 'a) -> Self {
into_ref!(channel);
Self { channel }
}
}
impl<'a, C: Channel> Drop for Transfer<'a, C> {
fn drop(&mut self) {
let p = self.channel.regs();
unsafe {
pac::DMA
.chan_abort()
.modify(|m| m.set_chan_abort(1 << self.channel.number()));
while p.ctrl_trig().read().busy() {}
}
}
}
impl<'a, C: Channel> Unpin for Transfer<'a, C> {}
impl<'a, C: Channel> Future for Transfer<'a, C> {
type Output = ();
fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
// We need to register/re-register the waker for each poll because any
// calls to wake will deregister the waker.
CHANNEL_WAKERS[self.channel.number() as usize].register(cx.waker());
if unsafe { self.channel.regs().ctrl_trig().read().busy() } {
Poll::Pending
} else {
Poll::Ready(())
}
}
}
pub(crate) const CHANNEL_COUNT: usize = 12;
const NEW_AW: AtomicWaker = AtomicWaker::new();
static CHANNEL_WAKERS: [AtomicWaker; CHANNEL_COUNT] = [NEW_AW; CHANNEL_COUNT];
mod sealed {
pub trait Channel {}
pub trait Word {}
}
pub trait Channel: Peripheral<P = Self> + sealed::Channel + Into<AnyChannel> + Sized + 'static {
fn number(&self) -> u8;
fn regs(&self) -> pac::dma::Channel {
pac::DMA.ch(self.number() as _)
}
fn degrade(self) -> AnyChannel {
AnyChannel { number: self.number() }
}
}
pub trait Word: sealed::Word {
fn size() -> vals::DataSize;
}
impl sealed::Word for u8 {}
impl Word for u8 {
fn size() -> vals::DataSize {
vals::DataSize::SIZE_BYTE
}
}
impl sealed::Word for u16 {}
impl Word for u16 {
fn size() -> vals::DataSize {
vals::DataSize::SIZE_HALFWORD
}
}
impl sealed::Word for u32 {}
impl Word for u32 {
fn size() -> vals::DataSize {
vals::DataSize::SIZE_WORD
}
}
pub struct AnyChannel {
number: u8,
}
impl_peripheral!(AnyChannel);
impl sealed::Channel for AnyChannel {}
impl Channel for AnyChannel {
fn number(&self) -> u8 {
self.number
}
}
macro_rules! channel {
($name:ident, $num:expr) => {
impl sealed::Channel for peripherals::$name {}
impl Channel for peripherals::$name {
fn number(&self) -> u8 {
$num
}
}
impl From<peripherals::$name> for crate::dma::AnyChannel {
fn from(val: peripherals::$name) -> Self {
crate::dma::Channel::degrade(val)
}
}
};
}
// TODO: replace transmutes with core::ptr::metadata once it's stable
#[allow(unused)]
pub(crate) fn slice_ptr_parts<T>(slice: *const [T]) -> (usize, usize) {
unsafe { core::mem::transmute(slice) }
}
#[allow(unused)]
pub(crate) fn slice_ptr_parts_mut<T>(slice: *mut [T]) -> (usize, usize) {
unsafe { core::mem::transmute(slice) }
}
channel!(DMA_CH0, 0);
channel!(DMA_CH1, 1);
channel!(DMA_CH2, 2);
channel!(DMA_CH3, 3);
channel!(DMA_CH4, 4);
channel!(DMA_CH5, 5);
channel!(DMA_CH6, 6);
channel!(DMA_CH7, 7);
channel!(DMA_CH8, 8);
channel!(DMA_CH9, 9);
channel!(DMA_CH10, 10);
channel!(DMA_CH11, 11);