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stm32/dma: make lowlevel api take ptrs instead of slices.

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This commit is contained in:
Dario Nieuwenhuis 2022-01-19 15:59:25 +01:00
parent 97ab859f00
commit 3d27a0e7cb
3 changed files with 48 additions and 29 deletions
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14
embassy-stm32/src/dma/bdma.rs
View file

@ -89,7 +89,8 @@ pac::dma_channels! {
($channel_peri:ident, $dma_peri:ident, bdma, $channel_num:expr, $dmamux:tt) => {
impl crate::dma::sealed::Channel for crate::peripherals::$channel_peri {
unsafe fn start_write<W: Word>(&mut self, request: Request, buf: &[W], reg_addr: *mut W) {
unsafe fn start_write<W: Word>(&mut self, request: Request, buf: *const[W], reg_addr: *mut W) {
let (ptr, len) = super::slice_ptr_parts(buf);
low_level_api::start_transfer(
pac::$dma_peri,
$channel_num,
@ -97,8 +98,8 @@ pac::dma_channels! {
request,
vals::Dir::FROMMEMORY,
reg_addr as *const u32,
buf.as_ptr() as *mut u32,
buf.len(),
ptr as *mut u32,
len,
true,
vals::Size::from(W::bits()),
#[cfg(dmamux)]
@ -129,7 +130,8 @@ pac::dma_channels! {
)
}
unsafe fn start_read<W: Word>(&mut self, request: Request, reg_addr: *mut W, buf: &mut [W]) {
unsafe fn start_read<W: Word>(&mut self, request: Request, reg_addr: *const W, buf: *mut [W]) {
let (ptr, len) = super::slice_ptr_parts_mut(buf);
low_level_api::start_transfer(
pac::$dma_peri,
$channel_num,
@ -137,8 +139,8 @@ pac::dma_channels! {
request,
vals::Dir::FROMPERIPHERAL,
reg_addr as *const u32,
buf.as_ptr() as *mut u32,
buf.len(),
ptr as *mut u32,
len,
true,
vals::Size::from(W::bits()),
#[cfg(dmamux)]

14
embassy-stm32/src/dma/dma.rs
View file

@ -84,15 +84,16 @@ pub(crate) unsafe fn init() {
pac::dma_channels! {
($channel_peri:ident, $dma_peri:ident, dma, $channel_num:expr, $dmamux:tt) => {
impl crate::dma::sealed::Channel for crate::peripherals::$channel_peri {
unsafe fn start_write<W: Word>(&mut self, request: Request, buf: &[W], reg_addr: *mut W) {
unsafe fn start_write<W: Word>(&mut self, request: Request, buf: *const [W], reg_addr: *mut W) {
let (ptr, len) = super::slice_ptr_parts(buf);
low_level_api::start_transfer(
pac::$dma_peri,
$channel_num,
request,
vals::Dir::MEMORYTOPERIPHERAL,
reg_addr as *const u32,
buf.as_ptr() as *mut u32,
buf.len(),
ptr as *mut u32,
len,
true,
vals::Size::from(W::bits()),
#[cfg(dmamux)]
@ -121,15 +122,16 @@ pac::dma_channels! {
)
}
unsafe fn start_read<W: Word>(&mut self, request: Request, reg_addr: *mut W, buf: &mut [W]) {
unsafe fn start_read<W: Word>(&mut self, request: Request, reg_addr: *const W, buf: *mut [W]) {
let (ptr, len) = super::slice_ptr_parts_mut(buf);
low_level_api::start_transfer(
pac::$dma_peri,
$channel_num,
request,
vals::Dir::PERIPHERALTOMEMORY,
reg_addr as *const u32,
buf.as_ptr() as *mut u32,
buf.len(),
ptr as *mut u32,
len,
true,
vals::Size::from(W::bits()),
#[cfg(dmamux)]

49
embassy-stm32/src/dma/mod.rs
View file

@ -10,6 +10,7 @@ pub use dmamux::*;
use core::future::Future;
use core::marker::PhantomData;
use core::mem;
use core::pin::Pin;
use core::task::Waker;
use core::task::{Context, Poll};
@ -36,12 +37,13 @@ pub(crate) mod sealed {
/// 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: &[W],
buf: *const [W],
reg_addr: *mut W,
);
@ -60,13 +62,14 @@ pub(crate) mod sealed {
/// 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 write to.
/// - `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: *mut W,
buf: &mut [W],
reg_addr: *const W,
buf: *mut [W],
);
/// Requests the channel to stop.
@ -132,10 +135,7 @@ mod transfers {
unsafe { channel.start_read::<W>(request, reg_addr, buf) };
Transfer {
channel,
_phantom: PhantomData,
}
Transfer::new(channel)
}
#[allow(unused)]
@ -150,10 +150,7 @@ mod transfers {
unsafe { channel.start_write::<W>(request, buf, reg_addr) };
Transfer {
channel,
_phantom: PhantomData,
}
Transfer::new(channel)
}
#[allow(unused)]
@ -168,17 +165,24 @@ mod transfers {
unsafe { channel.start_write_repeated::<W>(request, repeated, count, reg_addr) };
Transfer {
channel,
_phantom: PhantomData,
}
Transfer::new(channel)
}
struct Transfer<'a, C: Channel> {
pub(crate) struct Transfer<'a, C: Channel> {
channel: C,
_phantom: PhantomData<&'a mut C>,
}
impl<'a, C: Channel> Transfer<'a, C> {
pub(crate) fn new(channel: impl Unborrow<Target = C> + 'a) -> Self {
unborrow!(channel);
Self {
channel,
_phantom: PhantomData,
}
}
}
impl<'a, C: Channel> Drop for Transfer<'a, C> {
fn drop(&mut self) {
self.channel.request_stop();
@ -221,3 +225,14 @@ pub(crate) unsafe fn init() {
#[cfg(dmamux)]
dmamux::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) {
unsafe { mem::transmute(slice) }
}
#[allow(unused)]
pub(crate) fn slice_ptr_parts_mut<T>(slice: *mut [T]) -> (usize, usize) {
unsafe { mem::transmute(slice) }
}