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stm32/dma: refactor.

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This commit is contained in:
Dario Nieuwenhuis
2023-04-17 00:04:54 +02:00
parent 46227bec1e
commit 173c65b543
14 changed files with 1025 additions and 1092 deletions
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317
embassy-stm32/src/dma/mod.rs
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@ -1,124 +1,39 @@
#[cfg(bdma)]
pub(crate) mod bdma;
#[cfg(dma)]
pub(crate) mod dma;
#[cfg(dma)]
pub use dma::*;
// stm32h7 has both dma and bdma. In that case, we export dma as "main" dma,
// and bdma as "secondary", under `embassy_stm32::dma::bdma`.
#[cfg(all(bdma, dma))]
pub mod bdma;
#[cfg(all(bdma, not(dma)))]
pub(crate) mod bdma;
#[cfg(all(bdma, not(dma)))]
pub use bdma::*;
#[cfg(gpdma)]
pub(crate) mod gpdma;
#[cfg(gpdma)]
pub use gpdma::*;
#[cfg(dmamux)]
mod dmamux;
#[cfg(gpdma)]
mod gpdma;
use core::future::Future;
use core::mem;
use core::pin::Pin;
use core::task::{Context, Poll, Waker};
#[cfg(any(dma, bdma))]
use embassy_cortex_m::interrupt::Priority;
use embassy_hal_common::{impl_peripheral, into_ref};
use embassy_hal_common::impl_peripheral;
#[cfg(dmamux)]
pub use self::dmamux::*;
use crate::Peripheral;
#[cfg(feature = "unstable-pac")]
pub mod low_level {
pub use super::transfers::*;
}
pub(crate) use transfers::*;
#[cfg(any(bdma_v2, dma_v2, dmamux, gpdma))]
pub type Request = u8;
#[cfg(not(any(bdma_v2, dma_v2, dmamux, gpdma)))]
pub type Request = ();
pub(crate) mod sealed {
use super::*;
pub trait Word {}
pub trait Channel {
/// Starts this channel for writing a stream of words.
///
/// Safety:
/// - `buf` must point to a valid buffer for DMA reading.
/// - `buf` must be alive for the entire duration of the DMA transfer.
/// - `reg_addr` must be a valid peripheral register address to write to.
unsafe fn start_write<W: super::Word>(
&mut self,
request: Request,
buf: *const [W],
reg_addr: *mut W,
options: TransferOptions,
);
/// Starts this channel for writing a word repeatedly.
///
/// Safety:
/// - `reg_addr` must be a valid peripheral register address to write to.
unsafe fn start_write_repeated<W: super::Word>(
&mut self,
request: Request,
repeated: *const W,
count: usize,
reg_addr: *mut W,
options: TransferOptions,
);
/// Starts this channel for reading a stream of words.
///
/// Safety:
/// - `buf` must point to a valid buffer for DMA writing.
/// - `buf` must be alive for the entire duration of the DMA transfer.
/// - `reg_addr` must be a valid peripheral register address to read from.
unsafe fn start_read<W: super::Word>(
&mut self,
request: Request,
reg_addr: *const W,
buf: *mut [W],
options: TransferOptions,
);
/// DMA double-buffered mode is unsafe as UB can happen when the hardware writes to a buffer currently owned by the software
/// more information can be found here: https://github.com/embassy-rs/embassy/issues/702
/// This feature is now used solely for the purposes of implementing giant DMA transfers required for DCMI
unsafe fn start_double_buffered_read<W: super::Word>(
&mut self,
request: Request,
reg_addr: *const W,
buffer0: *mut W,
buffer1: *mut W,
buffer_len: usize,
options: TransferOptions,
);
unsafe fn set_buffer0<W: super::Word>(&mut self, buffer: *mut W);
unsafe fn set_buffer1<W: super::Word>(&mut self, buffer: *mut W);
unsafe fn is_buffer0_accessible(&mut self) -> bool;
/// Requests the channel to stop.
/// NOTE: The channel does not immediately stop, you have to wait
/// for `is_running() = false`.
fn request_stop(&mut self);
/// Returns whether this channel is running or stopped.
///
/// The channel stops running when it either completes or is manually stopped.
fn is_running(&self) -> bool;
/// Returns the total number of remaining transfers.
fn remaining_transfers(&mut self) -> u16;
/// Sets the waker that is called when this channel stops (either completed or manually stopped)
fn set_waker(&mut self, waker: &Waker);
/// This is called when this channel triggers an interrupt.
/// Note: Because some channels share an interrupt, this function might be
/// called for a channel that didn't trigger an interrupt.
fn on_irq();
}
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
enum Dir {
MemoryToPeripheral,
PeripheralToMemory,
}
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
@ -139,191 +54,39 @@ impl WordSize {
}
}
pub trait Word: sealed::Word {
mod word_sealed {
pub trait Word {}
}
pub trait Word: word_sealed::Word {
fn bits() -> WordSize;
}
impl sealed::Word for u8 {}
impl word_sealed::Word for u8 {}
impl Word for u8 {
fn bits() -> WordSize {
WordSize::OneByte
}
}
impl sealed::Word for u16 {}
impl word_sealed::Word for u16 {}
impl Word for u16 {
fn bits() -> WordSize {
WordSize::TwoBytes
}
}
impl sealed::Word for u32 {}
impl word_sealed::Word for u32 {}
impl Word for u32 {
fn bits() -> WordSize {
WordSize::FourBytes
}
}
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub enum Burst {
/// Single transfer
Single,
/// Incremental burst of 4 beats
Incr4,
/// Incremental burst of 8 beats
Incr8,
/// Incremental burst of 16 beats
Incr16,
}
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub enum FlowControl {
/// Flow control by DMA
Dma,
/// Flow control by peripheral
Peripheral,
}
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub enum FifoThreshold {
/// 1/4 full FIFO
Quarter,
/// 1/2 full FIFO
Half,
/// 3/4 full FIFO
ThreeQuarters,
/// Full FIFO
Full,
}
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub struct TransferOptions {
/// Peripheral burst transfer configuration
pub pburst: Burst,
/// Memory burst transfer configuration
pub mburst: Burst,
/// Flow control configuration
pub flow_ctrl: FlowControl,
/// FIFO threshold for DMA FIFO mode. If none, direct mode is used.
pub fifo_threshold: Option<FifoThreshold>,
}
impl Default for TransferOptions {
fn default() -> Self {
Self {
pburst: Burst::Single,
mburst: Burst::Single,
flow_ctrl: FlowControl::Dma,
fifo_threshold: None,
}
}
}
mod transfers {
use embassy_hal_common::PeripheralRef;
use super::*;
#[allow(unused)]
pub fn read<'a, W: Word>(
channel: impl Peripheral<P = impl Channel> + 'a,
request: Request,
reg_addr: *mut W,
buf: &'a mut [W],
) -> impl Future<Output = ()> + 'a {
assert!(buf.len() > 0 && buf.len() <= 0xFFFF);
into_ref!(channel);
unsafe { channel.start_read::<W>(request, reg_addr, buf, Default::default()) };
Transfer::new(channel)
}
#[allow(unused)]
pub fn write<'a, W: Word>(
channel: impl Peripheral<P = impl Channel> + 'a,
request: Request,
buf: &'a [W],
reg_addr: *mut W,
) -> impl Future<Output = ()> + 'a {
assert!(buf.len() > 0 && buf.len() <= 0xFFFF);
into_ref!(channel);
unsafe { channel.start_write::<W>(request, buf, reg_addr, Default::default()) };
Transfer::new(channel)
}
#[allow(unused)]
pub fn write_repeated<'a, W: Word>(
channel: impl Peripheral<P = impl Channel> + 'a,
request: Request,
repeated: *const W,
count: usize,
reg_addr: *mut W,
) -> impl Future<Output = ()> + 'a {
into_ref!(channel);
unsafe { channel.start_write_repeated::<W>(request, repeated, count, reg_addr, Default::default()) };
Transfer::new(channel)
}
#[must_use = "futures do nothing unless you `.await` or poll them"]
pub(crate) 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) {
self.channel.request_stop();
while self.channel.is_running() {}
}
}
impl<'a, C: Channel> Unpin for Transfer<'a, C> {}
impl<'a, C: Channel> Future for Transfer<'a, C> {
type Output = ();
fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
self.channel.set_waker(cx.waker());
if self.channel.is_running() {
Poll::Pending
} else {
Poll::Ready(())
}
}
}
}
pub trait Channel: sealed::Channel + Peripheral<P = Self> + 'static {}
pub struct NoDma;
impl_peripheral!(NoDma);
// safety: must be called only once at startup
pub(crate) unsafe fn init(#[cfg(bdma)] bdma_priority: Priority, #[cfg(dma)] dma_priority: Priority) {
#[cfg(bdma)]
bdma::init(bdma_priority);
#[cfg(dma)]
dma::init(dma_priority);
#[cfg(dmamux)]
dmamux::init();
#[cfg(gpdma)]
gpdma::init();
}
// 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) {
@ -334,3 +97,19 @@ pub(crate) fn slice_ptr_parts<T>(slice: *const [T]) -> (usize, usize) {
pub(crate) fn slice_ptr_parts_mut<T>(slice: *mut [T]) -> (usize, usize) {
unsafe { mem::transmute(slice) }
}
// safety: must be called only once at startup
pub(crate) unsafe fn init(
#[cfg(bdma)] bdma_priority: Priority,
#[cfg(dma)] dma_priority: Priority,
#[cfg(gpdma)] gpdma_priority: Priority,
) {
#[cfg(bdma)]
bdma::init(bdma_priority);
#[cfg(dma)]
dma::init(dma_priority);
#[cfg(gpdma)]
gpdma::init(gpdma_priority);
#[cfg(dmamux)]
dmamux::init();
}