embassy_stm32/dma/
mod.rs

1//! Direct Memory Access (DMA)
2#![macro_use]
3
4#[cfg(any(bdma, dma))]
5mod dma_bdma;
6#[cfg(any(bdma, dma))]
7pub use dma_bdma::*;
8
9#[cfg(gpdma)]
10pub(crate) mod gpdma;
11#[cfg(gpdma)]
12pub use gpdma::*;
13
14#[cfg(dmamux)]
15mod dmamux;
16#[cfg(dmamux)]
17pub(crate) use dmamux::*;
18
19mod util;
20pub(crate) use util::*;
21
22pub(crate) mod ringbuffer;
23pub mod word;
24
25use embassy_hal_internal::{impl_peripheral, Peripheral};
26
27use crate::interrupt;
28
29#[derive(Debug, Copy, Clone, PartialEq, Eq)]
30#[cfg_attr(feature = "defmt", derive(defmt::Format))]
31enum Dir {
32    MemoryToPeripheral,
33    PeripheralToMemory,
34}
35
36/// DMA request type alias. (also known as DMA channel number in some chips)
37#[cfg(any(dma_v2, bdma_v2, gpdma, dmamux))]
38pub type Request = u8;
39/// DMA request type alias. (also known as DMA channel number in some chips)
40#[cfg(not(any(dma_v2, bdma_v2, gpdma, dmamux)))]
41pub type Request = ();
42
43pub(crate) trait SealedChannel {
44    fn id(&self) -> u8;
45}
46
47pub(crate) trait ChannelInterrupt {
48    #[cfg_attr(not(feature = "rt"), allow(unused))]
49    unsafe fn on_irq();
50}
51
52/// DMA channel.
53#[allow(private_bounds)]
54pub trait Channel: SealedChannel + Peripheral<P = Self> + Into<AnyChannel> + 'static {
55    /// Type-erase (degrade) this pin into an `AnyChannel`.
56    ///
57    /// This converts DMA channel singletons (`DMA1_CH3`, `DMA2_CH1`, ...), which
58    /// are all different types, into the same type. It is useful for
59    /// creating arrays of channels, or avoiding generics.
60    #[inline]
61    fn degrade(self) -> AnyChannel {
62        AnyChannel { id: self.id() }
63    }
64}
65
66macro_rules! dma_channel_impl {
67    ($channel_peri:ident, $index:expr) => {
68        impl crate::dma::SealedChannel for crate::peripherals::$channel_peri {
69            fn id(&self) -> u8 {
70                $index
71            }
72        }
73        impl crate::dma::ChannelInterrupt for crate::peripherals::$channel_peri {
74            unsafe fn on_irq() {
75                crate::dma::AnyChannel { id: $index }.on_irq();
76            }
77        }
78
79        impl crate::dma::Channel for crate::peripherals::$channel_peri {}
80
81        impl From<crate::peripherals::$channel_peri> for crate::dma::AnyChannel {
82            fn from(x: crate::peripherals::$channel_peri) -> Self {
83                crate::dma::Channel::degrade(x)
84            }
85        }
86    };
87}
88
89/// Type-erased DMA channel.
90pub struct AnyChannel {
91    pub(crate) id: u8,
92}
93impl_peripheral!(AnyChannel);
94
95impl AnyChannel {
96    fn info(&self) -> &ChannelInfo {
97        &crate::_generated::DMA_CHANNELS[self.id as usize]
98    }
99}
100
101impl SealedChannel for AnyChannel {
102    fn id(&self) -> u8 {
103        self.id
104    }
105}
106impl Channel for AnyChannel {}
107
108const CHANNEL_COUNT: usize = crate::_generated::DMA_CHANNELS.len();
109static STATE: [ChannelState; CHANNEL_COUNT] = [ChannelState::NEW; CHANNEL_COUNT];
110
111/// "No DMA" placeholder.
112///
113/// You may pass this in place of a real DMA channel when creating a driver
114/// to indicate it should not use DMA.
115///
116/// This often causes async functionality to not be available on the instance,
117/// leaving only blocking functionality.
118pub struct NoDma;
119
120impl_peripheral!(NoDma);
121
122// safety: must be called only once at startup
123pub(crate) unsafe fn init(
124    cs: critical_section::CriticalSection,
125    #[cfg(bdma)] bdma_priority: interrupt::Priority,
126    #[cfg(dma)] dma_priority: interrupt::Priority,
127    #[cfg(gpdma)] gpdma_priority: interrupt::Priority,
128) {
129    #[cfg(any(dma, bdma))]
130    dma_bdma::init(
131        cs,
132        #[cfg(dma)]
133        dma_priority,
134        #[cfg(bdma)]
135        bdma_priority,
136    );
137    #[cfg(gpdma)]
138    gpdma::init(cs, gpdma_priority);
139    #[cfg(dmamux)]
140    dmamux::init(cs);
141}
embassy_stm32/dma/mod.rs

embassy_stm32/dma/
mod.rs
