diff --git a/embassy-stm32/build.rs b/embassy-stm32/build.rs
index 6c364f7b..aef0668a 100644
--- a/embassy-stm32/build.rs
+++ b/embassy-stm32/build.rs
@@ -308,6 +308,10 @@ fn main() {
// ========
// Generate RccPeripheral impls
+ // TODO: maybe get this from peripheral kind? Not sure
+ let refcounted_peripherals = HashSet::from(["USART"]);
+ let mut refcount_statics = HashSet::new();
+
for p in METADATA.peripherals {
// generating RccPeripheral impl for H7 ADC3 would result in bad frequency
if !singletons.contains(&p.name.to_string())
@@ -344,11 +348,36 @@ fn main() {
TokenStream::new()
};
+ let ptype = (if let Some(reg) = &p.registers { reg.kind } else { "" }).to_ascii_uppercase();
let pname = format_ident!("{}", p.name);
let clk = format_ident!("{}", rcc.clock.to_ascii_lowercase());
let en_reg = format_ident!("{}", en.register.to_ascii_lowercase());
let set_en_field = format_ident!("set_{}", en.field.to_ascii_lowercase());
+ let (before_enable, before_disable) = if refcounted_peripherals.contains(ptype.as_str()) {
+ let refcount_static =
+ format_ident!("{}_{}", en.register.to_ascii_uppercase(), en.field.to_ascii_uppercase());
+
+ refcount_statics.insert(refcount_static.clone());
+
+ (
+ quote! {
+ unsafe { refcount_statics::#refcount_static += 1 };
+ if unsafe { refcount_statics::#refcount_static } > 1 {
+ return;
+ }
+ },
+ quote! {
+ unsafe { refcount_statics::#refcount_static -= 1 };
+ if unsafe { refcount_statics::#refcount_static } > 0 {
+ return;
+ }
+ },
+ )
+ } else {
+ (TokenStream::new(), TokenStream::new())
+ };
+
g.extend(quote! {
impl crate::rcc::sealed::RccPeripheral for peripherals::#pname {
fn frequency() -> crate::time::Hertz {
@@ -356,6 +385,7 @@ fn main() {
}
fn enable() {
critical_section::with(|_| {
+ #before_enable
#[cfg(feature = "low-power")]
crate::rcc::clock_refcount_add();
crate::pac::RCC.#en_reg().modify(|w| w.#set_en_field(true));
@@ -364,6 +394,7 @@ fn main() {
}
fn disable() {
critical_section::with(|_| {
+ #before_disable
crate::pac::RCC.#en_reg().modify(|w| w.#set_en_field(false));
#[cfg(feature = "low-power")]
crate::rcc::clock_refcount_sub();
@@ -379,6 +410,19 @@ fn main() {
}
}
+ let mut refcount_mod = TokenStream::new();
+ for refcount_static in refcount_statics {
+ refcount_mod.extend(quote! {
+ pub(crate) static mut #refcount_static: u8 = 0;
+ });
+ }
+
+ g.extend(quote! {
+ mod refcount_statics {
+ #refcount_mod
+ }
+ });
+
// ========
// Generate fns to enable GPIO, DMA in RCC
diff --git a/embassy-stm32/src/i2c/v1.rs b/embassy-stm32/src/i2c/v1.rs
index 618d85af..f32dd0f0 100644
--- a/embassy-stm32/src/i2c/v1.rs
+++ b/embassy-stm32/src/i2c/v1.rs
@@ -339,6 +339,12 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
}
}
+impl<'d, T: Instance, TXDMA, RXDMA> Drop for I2c<'d, T, TXDMA, RXDMA> {
+ fn drop(&mut self) {
+ T::disable();
+ }
+}
+
impl<'d, T: Instance> embedded_hal_02::blocking::i2c::Read for I2c<'d, T> {
type Error = Error;
diff --git a/embassy-stm32/src/i2c/v2.rs b/embassy-stm32/src/i2c/v2.rs
index 4327899b..36f70e32 100644
--- a/embassy-stm32/src/i2c/v2.rs
+++ b/embassy-stm32/src/i2c/v2.rs
@@ -838,6 +838,12 @@ impl<'d, T: Instance, TXDMA, RXDMA> I2c<'d, T, TXDMA, RXDMA> {
}
}
+impl<'d, T: Instance, TXDMA, RXDMA> Drop for I2c<'d, T, TXDMA, RXDMA> {
+ fn drop(&mut self) {
+ T::disable();
+ }
+}
+
mod eh02 {
use super::*;
diff --git a/embassy-stm32/src/spi/mod.rs b/embassy-stm32/src/spi/mod.rs
index e2bc8d7f..853de98f 100644
--- a/embassy-stm32/src/spi/mod.rs
+++ b/embassy-stm32/src/spi/mod.rs
@@ -646,6 +646,8 @@ impl<'d, T: Instance, Tx, Rx> Drop for Spi<'d, T, Tx, Rx> {
self.sck.as_ref().map(|x| x.set_as_disconnected());
self.mosi.as_ref().map(|x| x.set_as_disconnected());
self.miso.as_ref().map(|x| x.set_as_disconnected());
+
+ T::disable();
}
}
diff --git a/embassy-stm32/src/usart/buffered.rs b/embassy-stm32/src/usart/buffered.rs
index 596d40bf..989c8820 100644
--- a/embassy-stm32/src/usart/buffered.rs
+++ b/embassy-stm32/src/usart/buffered.rs
@@ -124,6 +124,8 @@ impl<'d, T: BasicInstance> BufferedUart<'d, T> {
rx_buffer: &'d mut [u8],
config: Config,
) -> BufferedUart<'d, T> {
+ // UartRx and UartTx have one refcount ea.
+ T::enable();
T::enable();
T::reset();
@@ -143,6 +145,8 @@ impl<'d, T: BasicInstance> BufferedUart<'d, T> {
) -> BufferedUart<'d, T> {
into_ref!(cts, rts);
+ // UartRx and UartTx have one refcount ea.
+ T::enable();
T::enable();
T::reset();
@@ -169,6 +173,8 @@ impl<'d, T: BasicInstance> BufferedUart<'d, T> {
) -> BufferedUart<'d, T> {
into_ref!(de);
+ // UartRx and UartTx have one refcount ea.
+ T::enable();
T::enable();
T::reset();
@@ -382,6 +388,8 @@ impl<'d, T: BasicInstance> Drop for BufferedUartRx<'d, T> {
T::Interrupt::disable();
}
}
+
+ T::disable();
}
}
@@ -397,6 +405,8 @@ impl<'d, T: BasicInstance> Drop for BufferedUartTx<'d, T> {
T::Interrupt::disable();
}
}
+
+ T::disable();
}
}
diff --git a/embassy-stm32/src/usart/mod.rs b/embassy-stm32/src/usart/mod.rs
index 255ddfd4..bfb05671 100644
--- a/embassy-stm32/src/usart/mod.rs
+++ b/embassy-stm32/src/usart/mod.rs
@@ -618,6 +618,18 @@ impl<'d, T: BasicInstance, RxDma> UartRx<'d, T, RxDma> {
}
}
+impl<'d, T: BasicInstance, TxDma> Drop for UartTx<'d, T, TxDma> {
+ fn drop(&mut self) {
+ T::disable();
+ }
+}
+
+impl<'d, T: BasicInstance, TxDma> Drop for UartRx<'d, T, TxDma> {
+ fn drop(&mut self) {
+ T::disable();
+ }
+}
+
impl<'d, T: BasicInstance, TxDma, RxDma> Uart<'d, T, TxDma, RxDma> {
pub fn new(
peri: impl Peripheral + 'd,
@@ -628,6 +640,8 @@ impl<'d, T: BasicInstance, TxDma, RxDma> Uart<'d, T, TxDma, RxDma> {
rx_dma: impl Peripheral
+ 'd,
config: Config,
) -> Self {
+ // UartRx and UartTx have one refcount ea.
+ T::enable();
T::enable();
T::reset();
@@ -647,6 +661,8 @@ impl<'d, T: BasicInstance, TxDma, RxDma> Uart<'d, T, TxDma, RxDma> {
) -> Self {
into_ref!(cts, rts);
+ // UartRx and UartTx have one refcount ea.
+ T::enable();
T::enable();
T::reset();
@@ -672,6 +688,8 @@ impl<'d, T: BasicInstance, TxDma, RxDma> Uart<'d, T, TxDma, RxDma> {
) -> Self {
into_ref!(de);
+ // UartRx and UartTx have one refcount ea.
+ T::enable();
T::enable();
T::reset();
diff --git a/embassy-stm32/src/usart/ringbuffered.rs b/embassy-stm32/src/usart/ringbuffered.rs
index b3f57062..e990eaca 100644
--- a/embassy-stm32/src/usart/ringbuffered.rs
+++ b/embassy-stm32/src/usart/ringbuffered.rs
@@ -1,4 +1,5 @@
use core::future::poll_fn;
+use core::mem;
use core::sync::atomic::{compiler_fence, Ordering};
use core::task::Poll;
@@ -24,12 +25,16 @@ impl<'d, T: BasicInstance, RxDma: super::RxDma> UartRx<'d, T, RxDma> {
let request = self.rx_dma.request();
let opts = Default::default();
- let ring_buf = unsafe { ReadableRingBuffer::new_read(self.rx_dma, request, rdr(T::regs()), dma_buf, opts) };
+ // Safety: we forget the struct before this function returns.
+ let rx_dma = unsafe { self.rx_dma.clone_unchecked() };
+ let _peri = unsafe { self._peri.clone_unchecked() };
- RingBufferedUartRx {
- _peri: self._peri,
- ring_buf,
- }
+ let ring_buf = unsafe { ReadableRingBuffer::new_read(rx_dma, request, rdr(T::regs()), dma_buf, opts) };
+
+ // Don't disable the clock
+ mem::forget(self);
+
+ RingBufferedUartRx { _peri, ring_buf }
}
}
@@ -186,6 +191,8 @@ impl<'d, T: BasicInstance, RxDma: super::RxDma> RingBufferedUartRx<'d, T, RxD
impl> Drop for RingBufferedUartRx<'_, T, RxDma> {
fn drop(&mut self) {
self.teardown_uart();
+
+ T::disable();
}
}
/// Return an error result if the Sr register has errors