Merge pull request #3006 from honzasp/harmonize-new

stm32: Make initialization of I2C and USART consistent with SPI

7 files changed, 257 insertions, 180 deletions

diff --git a/embassy-stm32/src/i2c/mod.rs b/embassy-stm32/src/i2c/mod.rs
index 0bf57ef8a..6d12af2cc 100644
--- a/embassy-stm32/src/i2c/mod.rs
+++ b/embassy-stm32/src/i2c/mod.rs
@@ -9,16 +9,16 @@ use core::future::Future;
 use core::iter;
 use core::marker::PhantomData;
 
-use embassy_hal_internal::{into_ref, Peripheral};
+use embassy_hal_internal::{Peripheral, PeripheralRef};
 use embassy_sync::waitqueue::AtomicWaker;
 #[cfg(feature = "time")]
 use embassy_time::{Duration, Instant};
 
 use crate::dma::ChannelAndRequest;
-use crate::gpio::{AFType, Pull};
+use crate::gpio::{AFType, AnyPin, Pull, SealedPin as _, Speed};
 use crate::interrupt::typelevel::Interrupt;
 use crate::mode::{Async, Blocking, Mode};
-use crate::rcc::{self, RccInfo, SealedRccPeripheral};
+use crate::rcc::{RccInfo, SealedRccPeripheral};
 use crate::time::Hertz;
 use crate::{interrupt, peripherals};
 
@@ -72,11 +72,29 @@ impl Default for Config {
     }
 }
 
+impl Config {
+    fn scl_pull_mode(&self) -> Pull {
+        match self.scl_pullup {
+            true => Pull::Up,
+            false => Pull::Down,
+        }
+    }
+
+    fn sda_pull_mode(&self) -> Pull {
+        match self.sda_pullup {
+            true => Pull::Up,
+            false => Pull::Down,
+        }
+    }
+}
+
 /// I2C driver.
 pub struct I2c<'d, M: Mode> {
     info: &'static Info,
     state: &'static State,
     kernel_clock: Hertz,
+    scl: Option<PeripheralRef<'d, AnyPin>>,
+    sda: Option<PeripheralRef<'d, AnyPin>>,
     tx_dma: Option<ChannelAndRequest<'d>>,
     rx_dma: Option<ChannelAndRequest<'d>>,
     #[cfg(feature = "time")]
@@ -98,7 +116,15 @@ impl<'d> I2c<'d, Async> {
         freq: Hertz,
         config: Config,
     ) -> Self {
-        Self::new_inner(peri, scl, sda, new_dma!(tx_dma), new_dma!(rx_dma), freq, config)
+        Self::new_inner(
+            peri,
+            new_pin!(scl, AFType::OutputOpenDrain, Speed::Medium, config.scl_pull_mode()),
+            new_pin!(sda, AFType::OutputOpenDrain, Speed::Medium, config.sda_pull_mode()),
+            new_dma!(tx_dma),
+            new_dma!(rx_dma),
+            freq,
+            config,
+        )
     }
 }
 
@@ -111,7 +137,15 @@ impl<'d> I2c<'d, Blocking> {
         freq: Hertz,
         config: Config,
     ) -> Self {
-        Self::new_inner(peri, scl, sda, None, None, freq, config)
+        Self::new_inner(
+            peri,
+            new_pin!(scl, AFType::OutputOpenDrain, Speed::Medium, config.scl_pull_mode()),
+            new_pin!(sda, AFType::OutputOpenDrain, Speed::Medium, config.sda_pull_mode()),
+            None,
+            None,
+            freq,
+            config,
+        )
     }
 }
 
@@ -119,34 +153,13 @@ impl<'d, M: Mode> I2c<'d, M> {
     /// Create a new I2C driver.
     fn new_inner<T: Instance>(
         _peri: impl Peripheral<P = T> + 'd,
-        scl: impl Peripheral<P = impl SclPin<T>> + 'd,
-        sda: impl Peripheral<P = impl SdaPin<T>> + 'd,
+        scl: Option<PeripheralRef<'d, AnyPin>>,
+        sda: Option<PeripheralRef<'d, AnyPin>>,
         tx_dma: Option<ChannelAndRequest<'d>>,
         rx_dma: Option<ChannelAndRequest<'d>>,
         freq: Hertz,
         config: Config,
     ) -> Self {
-        into_ref!(scl, sda);
-
-        rcc::enable_and_reset::<T>();
-
-        scl.set_as_af_pull(
-            scl.af_num(),
-            AFType::OutputOpenDrain,
-            match config.scl_pullup {
-                true => Pull::Up,
-                false => Pull::None,
-            },
-        );
-        sda.set_as_af_pull(
-            sda.af_num(),
-            AFType::OutputOpenDrain,
-            match config.sda_pullup {
-                true => Pull::Up,
-                false => Pull::None,
-            },
-        );
-
         unsafe { T::EventInterrupt::enable() };
         unsafe { T::ErrorInterrupt::enable() };
 
@@ -154,18 +167,23 @@ impl<'d, M: Mode> I2c<'d, M> {
             info: T::info(),
             state: T::state(),
             kernel_clock: T::frequency(),
+            scl,
+            sda,
             tx_dma,
             rx_dma,
             #[cfg(feature = "time")]
             timeout: config.timeout,
             _phantom: PhantomData,
         };
-
-        this.init(freq, config);
-
+        this.enable_and_init(freq, config);
         this
     }
 
+    fn enable_and_init(&mut self, freq: Hertz, config: Config) {
+        self.info.rcc.enable_and_reset();
+        self.init(freq, config);
+    }
+
     fn timeout(&self) -> Timeout {
         Timeout {
             #[cfg(feature = "time")]
@@ -174,6 +192,15 @@ impl<'d, M: Mode> I2c<'d, M> {
     }
 }
 
+impl<'d, M: Mode> Drop for I2c<'d, M> {
+    fn drop(&mut self) {
+        self.scl.as_ref().map(|x| x.set_as_disconnected());
+        self.sda.as_ref().map(|x| x.set_as_disconnected());
+
+        self.info.rcc.disable()
+    }
+}
+
 #[derive(Copy, Clone)]
 struct Timeout {
     #[cfg(feature = "time")]
diff --git a/embassy-stm32/src/i2c/v1.rs b/embassy-stm32/src/i2c/v1.rs
index 0e2bd2e40..28026f83c 100644
--- a/embassy-stm32/src/i2c/v1.rs
+++ b/embassy-stm32/src/i2c/v1.rs
@@ -700,12 +700,6 @@ impl<'d> I2c<'d, Async> {
     }
 }
 
-impl<'d, M: PeriMode> Drop for I2c<'d, M> {
-    fn drop(&mut self) {
-        self.info.rcc.disable()
-    }
-}
-
 enum Mode {
     Fast,
     Standard,
diff --git a/embassy-stm32/src/i2c/v2.rs b/embassy-stm32/src/i2c/v2.rs
index 193f29733..80163c287 100644
--- a/embassy-stm32/src/i2c/v2.rs
+++ b/embassy-stm32/src/i2c/v2.rs
@@ -671,12 +671,6 @@ impl<'d> I2c<'d, Async> {
     }
 }
 
-impl<'d, M: Mode> Drop for I2c<'d, M> {
-    fn drop(&mut self) {
-        self.info.rcc.disable();
-    }
-}
-
 /// I2C Stop Configuration
 ///
 /// Peripheral options for generating the STOP condition
diff --git a/embassy-stm32/src/spi/mod.rs b/embassy-stm32/src/spi/mod.rs
index 720e80e0d..4eaf7777f 100644
--- a/embassy-stm32/src/spi/mod.rs
+++ b/embassy-stm32/src/spi/mod.rs
@@ -13,7 +13,7 @@ use crate::dma::{slice_ptr_parts, word, ChannelAndRequest};
 use crate::gpio::{AFType, AnyPin, Pull, SealedPin as _, Speed};
 use crate::mode::{Async, Blocking, Mode as PeriMode};
 use crate::pac::spi::{regs, vals, Spi as Regs};
-use crate::rcc::{self, RccInfo, SealedRccPeripheral};
+use crate::rcc::{RccInfo, SealedRccPeripheral};
 use crate::time::Hertz;
 use crate::Peripheral;
 
@@ -120,17 +120,30 @@ impl<'d, M: PeriMode> Spi<'d, M> {
         rx_dma: Option<ChannelAndRequest<'d>>,
         config: Config,
     ) -> Self {
-        let regs = T::info().regs;
-        let kernel_clock = T::frequency();
-        let br = compute_baud_rate(kernel_clock, config.frequency);
+        let mut this = Self {
+            info: T::info(),
+            kernel_clock: T::frequency(),
+            sck,
+            mosi,
+            miso,
+            tx_dma,
+            rx_dma,
+            current_word_size: <u8 as SealedWord>::CONFIG,
+            _phantom: PhantomData,
+        };
+        this.enable_and_init(config);
+        this
+    }
 
+    fn enable_and_init(&mut self, config: Config) {
+        let br = compute_baud_rate(self.kernel_clock, config.frequency);
         let cpha = config.raw_phase();
         let cpol = config.raw_polarity();
-
         let lsbfirst = config.raw_byte_order();
 
-        rcc::enable_and_reset::<T>();
+        self.info.rcc.enable_and_reset();
 
+        let regs = self.info.regs;
         #[cfg(any(spi_v1, spi_f1))]
         {
             regs.cr2().modify(|w| {
@@ -209,18 +222,6 @@ impl<'d, M: PeriMode> Spi<'d, M> {
                 w.set_spe(true);
             });
         }
-
-        Self {
-            info: T::info(),
-            kernel_clock,
-            sck,
-            mosi,
-            miso,
-            tx_dma,
-            rx_dma,
-            current_word_size: <u8 as SealedWord>::CONFIG,
-            _phantom: PhantomData,
-        }
     }
 
     /// Reconfigures it with the supplied config.
@@ -611,7 +612,7 @@ impl<'d> Spi<'d, Async> {
         // see RM0453 rev 1 section 7.2.13 page 291
         // The SUBGHZSPI_SCK frequency is obtained by PCLK3 divided by two.
         // The SUBGHZSPI_SCK clock maximum speed must not exceed 16 MHz.
-        let pclk3_freq = <crate::peripherals::SUBGHZSPI as crate::rcc::SealedRccPeripheral>::frequency().0;
+        let pclk3_freq = <crate::peripherals::SUBGHZSPI as SealedRccPeripheral>::frequency().0;
         let freq = Hertz(core::cmp::min(pclk3_freq / 2, 16_000_000));
         let mut config = Config::default();
         config.mode = MODE_0;
diff --git a/embassy-stm32/src/usart/buffered.rs b/embassy-stm32/src/usart/buffered.rs
index eacf95002..fd79e035e 100644
--- a/embassy-stm32/src/usart/buffered.rs
+++ b/embassy-stm32/src/usart/buffered.rs
@@ -6,7 +6,7 @@ use core::task::Poll;
 
 use embassy_embedded_hal::SetConfig;
 use embassy_hal_internal::atomic_ring_buffer::RingBuffer;
-use embassy_hal_internal::{into_ref, Peripheral};
+use embassy_hal_internal::{Peripheral, PeripheralRef};
 use embassy_sync::waitqueue::AtomicWaker;
 
 #[cfg(not(any(usart_v1, usart_v2)))]
@@ -15,10 +15,8 @@ use super::{
     clear_interrupt_flags, configure, rdr, reconfigure, sr, tdr, Config, ConfigError, CtsPin, Error, Info, Instance,
     Regs, RtsPin, RxPin, TxPin,
 };
-use crate::gpio::AFType;
-use crate::interrupt::typelevel::Interrupt as _;
+use crate::gpio::{AFType, AnyPin, SealedPin as _};
 use crate::interrupt::{self, InterruptExt};
-use crate::rcc;
 use crate::time::Hertz;
 
 /// Interrupt handler.
@@ -156,7 +154,9 @@ pub struct BufferedUartTx<'d> {
     info: &'static Info,
     state: &'static State,
     kernel_clock: Hertz,
-    _phantom: PhantomData<&'d mut ()>,
+    tx: Option<PeripheralRef<'d, AnyPin>>,
+    cts: Option<PeripheralRef<'d, AnyPin>>,
+    de: Option<PeripheralRef<'d, AnyPin>>,
 }
 
 /// Rx-only buffered UART
@@ -166,7 +166,8 @@ pub struct BufferedUartRx<'d> {
     info: &'static Info,
     state: &'static State,
     kernel_clock: Hertz,
-    _phantom: PhantomData<&'d mut ()>,
+    rx: Option<PeripheralRef<'d, AnyPin>>,
+    rts: Option<PeripheralRef<'d, AnyPin>>,
 }
 
 impl<'d> SetConfig for BufferedUart<'d> {
@@ -207,9 +208,17 @@ impl<'d> BufferedUart<'d> {
         rx_buffer: &'d mut [u8],
         config: Config,
     ) -> Result<Self, ConfigError> {
-        rcc::enable_and_reset::<T>();
-
-        Self::new_inner(peri, rx, tx, tx_buffer, rx_buffer, config)
+        Self::new_inner(
+            peri,
+            new_pin!(rx, AFType::Input),
+            new_pin!(tx, AFType::OutputPushPull),
+            None,
+            None,
+            None,
+            tx_buffer,
+            rx_buffer,
+            config,
+        )
     }
 
     /// Create a new bidirectional buffered UART driver with request-to-send and clear-to-send pins
@@ -224,18 +233,17 @@ impl<'d> BufferedUart<'d> {
         rx_buffer: &'d mut [u8],
         config: Config,
     ) -> Result<Self, ConfigError> {
-        into_ref!(cts, rts);
-
-        rcc::enable_and_reset::<T>();
-
-        rts.set_as_af(rts.af_num(), AFType::OutputPushPull);
-        cts.set_as_af(cts.af_num(), AFType::Input);
-        T::info().regs.cr3().write(|w| {
-            w.set_rtse(true);
-            w.set_ctse(true);
-        });
-
-        Self::new_inner(peri, rx, tx, tx_buffer, rx_buffer, config)
+        Self::new_inner(
+            peri,
+            new_pin!(rx, AFType::Input),
+            new_pin!(tx, AFType::OutputPushPull),
+            new_pin!(rts, AFType::OutputPushPull),
+            new_pin!(cts, AFType::Input),
+            None,
+            tx_buffer,
+            rx_buffer,
+            config,
+        )
     }
 
     /// Create a new bidirectional buffered UART driver with a driver-enable pin
@@ -250,66 +258,89 @@ impl<'d> BufferedUart<'d> {
         rx_buffer: &'d mut [u8],
         config: Config,
     ) -> Result<Self, ConfigError> {
-        into_ref!(de);
-
-        rcc::enable_and_reset::<T>();
-
-        de.set_as_af(de.af_num(), AFType::OutputPushPull);
-        T::info().regs.cr3().write(|w| {
-            w.set_dem(true);
-        });
-
-        Self::new_inner(peri, rx, tx, tx_buffer, rx_buffer, config)
+        Self::new_inner(
+            peri,
+            new_pin!(rx, AFType::Input),
+            new_pin!(tx, AFType::OutputPushPull),
+            None,
+            None,
+            new_pin!(de, AFType::OutputPushPull),
+            tx_buffer,
+            rx_buffer,
+            config,
+        )
     }
 
     fn new_inner<T: Instance>(
         _peri: impl Peripheral<P = T> + 'd,
-        rx: impl Peripheral<P = impl RxPin<T>> + 'd,
-        tx: impl Peripheral<P = impl TxPin<T>> + 'd,
+        rx: Option<PeripheralRef<'d, AnyPin>>,
+        tx: Option<PeripheralRef<'d, AnyPin>>,
+        rts: Option<PeripheralRef<'d, AnyPin>>,
+        cts: Option<PeripheralRef<'d, AnyPin>>,
+        de: Option<PeripheralRef<'d, AnyPin>>,
         tx_buffer: &'d mut [u8],
         rx_buffer: &'d mut [u8],
         config: Config,
     ) -> Result<Self, ConfigError> {
-        into_ref!(_peri, rx, tx);
-
         let info = T::info();
         let state = T::buffered_state();
         let kernel_clock = T::frequency();
-        let len = tx_buffer.len();
-        unsafe { state.tx_buf.init(tx_buffer.as_mut_ptr(), len) };
-        let len = rx_buffer.len();
-        unsafe { state.rx_buf.init(rx_buffer.as_mut_ptr(), len) };
-
-        let r = info.regs;
-        rx.set_as_af(rx.af_num(), AFType::Input);
-        tx.set_as_af(tx.af_num(), AFType::OutputPushPull);
-
-        configure(info, kernel_clock, &config, true, true)?;
-
-        r.cr1().modify(|w| {
-            w.set_rxneie(true);
-            w.set_idleie(true);
-        });
-
-        T::Interrupt::unpend();
-        unsafe { T::Interrupt::enable() };
 
-        state.tx_rx_refcount.store(2, Ordering::Relaxed);
-
-        Ok(Self {
+        let mut this = Self {
             rx: BufferedUartRx {
                 info,
                 state,
                 kernel_clock,
-                _phantom: PhantomData,
+                rx,
+                rts,
             },
             tx: BufferedUartTx {
                 info,
                 state,
                 kernel_clock,
-                _phantom: PhantomData,
+                tx,
+                cts,
+                de,
             },
-        })
+        };
+        this.enable_and_configure(tx_buffer, rx_buffer, &config)?;
+        Ok(this)
+    }
+
+    fn enable_and_configure(
+        &mut self,
+        tx_buffer: &'d mut [u8],
+        rx_buffer: &'d mut [u8],
+        config: &Config,
+    ) -> Result<(), ConfigError> {
+        let info = self.rx.info;
+        let state = self.rx.state;
+        state.tx_rx_refcount.store(2, Ordering::Relaxed);
+
+        info.rcc.enable_and_reset();
+
+        let len = tx_buffer.len();
+        unsafe { state.tx_buf.init(tx_buffer.as_mut_ptr(), len) };
+        let len = rx_buffer.len();
+        unsafe { state.rx_buf.init(rx_buffer.as_mut_ptr(), len) };
+
+        info.regs.cr3().write(|w| {
+            w.set_rtse(self.rx.rts.is_some());
+            w.set_ctse(self.tx.cts.is_some());
+            #[cfg(not(any(usart_v1, usart_v2)))]
+            w.set_dem(self.tx.de.is_some());
+        });
+        configure(info, self.rx.kernel_clock, &config, true, true)?;
+
+        info.regs.cr1().modify(|w| {
+            w.set_rxneie(true);
+            w.set_idleie(true);
+        });
+
+        info.interrupt.unpend();
+        unsafe { info.interrupt.enable() };
+
+        Ok(())
     }
 
     /// Split the driver into a Tx and Rx part (useful for sending to separate tasks)
@@ -516,6 +547,8 @@ impl<'d> Drop for BufferedUartRx<'d> {
             }
         }
 
+        self.rx.as_ref().map(|x| x.set_as_disconnected());
+        self.rts.as_ref().map(|x| x.set_as_disconnected());
         drop_tx_rx(self.info, state);
     }
 }
@@ -533,6 +566,9 @@ impl<'d> Drop for BufferedUartTx<'d> {
             }
         }
 
+        self.tx.as_ref().map(|x| x.set_as_disconnected());
+        self.cts.as_ref().map(|x| x.set_as_disconnected());
+        self.de.as_ref().map(|x| x.set_as_disconnected());
         drop_tx_rx(self.info, state);
     }
 }
diff --git a/embassy-stm32/src/usart/mod.rs b/embassy-stm32/src/usart/mod.rs
index 2a39c6301..53321391a 100644
--- a/embassy-stm32/src/usart/mod.rs
+++ b/embassy-stm32/src/usart/mod.rs
@@ -14,7 +14,7 @@ use embassy_sync::waitqueue::AtomicWaker;
 use futures_util::future::{select, Either};
 
 use crate::dma::ChannelAndRequest;
-use crate::gpio::{AFType, AnyPin, SealedPin};
+use crate::gpio::{AFType, AnyPin, SealedPin as _};
 use crate::interrupt::typelevel::Interrupt as _;
 use crate::interrupt::{self, Interrupt, InterruptExt};
 use crate::mode::{Async, Blocking, Mode};
@@ -28,7 +28,7 @@ use crate::pac::usart::Lpuart as Regs;
 #[cfg(any(usart_v1, usart_v2))]
 use crate::pac::usart::Usart as Regs;
 use crate::pac::usart::{regs, vals};
-use crate::rcc::{self, RccInfo, SealedRccPeripheral};
+use crate::rcc::{RccInfo, SealedRccPeripheral};
 use crate::time::Hertz;
 use crate::Peripheral;
 
@@ -429,29 +429,33 @@ impl<'d, M: Mode> UartTx<'d, M> {
         tx_dma: Option<ChannelAndRequest<'d>>,
         config: Config,
     ) -> Result<Self, ConfigError> {
-        rcc::enable_and_reset::<T>();
-
-        let info = T::info();
-        let state = T::state();
-        let kernel_clock = T::frequency();
-        let r = info.regs;
-        r.cr3().modify(|w| {
-            w.set_ctse(cts.is_some());
-        });
-        configure(info, kernel_clock, &config, false, true)?;
-
-        state.tx_rx_refcount.store(1, Ordering::Relaxed);
-
-        Ok(Self {
-            info,
-            state,
-            kernel_clock,
+        let mut this = Self {
+            info: T::info(),
+            state: T::state(),
+            kernel_clock: T::frequency(),
             tx,
             cts,
             de: None,
             tx_dma,
             _phantom: PhantomData,
-        })
+        };
+        this.enable_and_configure(&config)?;
+        Ok(this)
+    }
+
+    fn enable_and_configure(&mut self, config: &Config) -> Result<(), ConfigError> {
+        let info = self.info;
+        let state = self.state;
+        state.tx_rx_refcount.store(1, Ordering::Relaxed);
+
+        info.rcc.enable_and_reset();
+
+        info.regs.cr3().modify(|w| {
+            w.set_ctse(self.cts.is_some());
+        });
+        configure(info, self.kernel_clock, config, false, true)?;
+
+        Ok(())
     }
 
     /// Reconfigure the driver
@@ -775,34 +779,38 @@ impl<'d, M: Mode> UartRx<'d, M> {
         rx_dma: Option<ChannelAndRequest<'d>>,
         config: Config,
     ) -> Result<Self, ConfigError> {
-        rcc::enable_and_reset::<T>();
-
-        let info = T::info();
-        let state = T::state();
-        let kernel_clock = T::frequency();
-        let r = info.regs;
-        r.cr3().write(|w| {
-            w.set_rtse(rts.is_some());
-        });
-        configure(info, kernel_clock, &config, true, false)?;
-
-        T::Interrupt::unpend();
-        unsafe { T::Interrupt::enable() };
-
-        state.tx_rx_refcount.store(1, Ordering::Relaxed);
-
-        Ok(Self {
+        let mut this = Self {
             _phantom: PhantomData,
-            info,
-            state,
-            kernel_clock,
+            info: T::info(),
+            state: T::state(),
+            kernel_clock: T::frequency(),
             rx,
             rts,
             rx_dma,
             detect_previous_overrun: config.detect_previous_overrun,
             #[cfg(any(usart_v1, usart_v2))]
             buffered_sr: stm32_metapac::usart::regs::Sr(0),
-        })
+        };
+        this.enable_and_configure(&config)?;
+        Ok(this)
+    }
+
+    fn enable_and_configure(&mut self, config: &Config) -> Result<(), ConfigError> {
+        let info = self.info;
+        let state = self.state;
+        state.tx_rx_refcount.store(1, Ordering::Relaxed);
+
+        info.rcc.enable_and_reset();
+
+        info.regs.cr3().write(|w| {
+            w.set_rtse(self.rts.is_some());
+        });
+        configure(info, self.kernel_clock, &config, true, false)?;
+
+        info.interrupt.unpend();
+        unsafe { info.interrupt.enable() };
+
+        Ok(())
     }
 
     /// Reconfigure the driver
@@ -1228,27 +1236,11 @@ impl<'d, M: Mode> Uart<'d, M> {
         rx_dma: Option<ChannelAndRequest<'d>>,
         config: Config,
     ) -> Result<Self, ConfigError> {
-        rcc::enable_and_reset::<T>();
-
         let info = T::info();
         let state = T::state();
         let kernel_clock = T::frequency();
-        let r = info.regs;
-
-        r.cr3().write(|w| {
-            w.set_rtse(rts.is_some());
-            w.set_ctse(cts.is_some());
-            #[cfg(not(any(usart_v1, usart_v2)))]
-            w.set_dem(de.is_some());
-        });
-        configure(info, kernel_clock, &config, true, true)?;
-
-        T::Interrupt::unpend();
-        unsafe { T::Interrupt::enable() };
 
-        state.tx_rx_refcount.store(2, Ordering::Relaxed);
-
-        Ok(Self {
+        let mut this = Self {
             tx: UartTx {
                 _phantom: PhantomData,
                 info,
@@ -1271,7 +1263,30 @@ impl<'d, M: Mode> Uart<'d, M> {
                 #[cfg(any(usart_v1, usart_v2))]
                 buffered_sr: stm32_metapac::usart::regs::Sr(0),
             },
-        })
+        };
+        this.enable_and_configure(&config)?;
+        Ok(this)
+    }
+
+    fn enable_and_configure(&mut self, config: &Config) -> Result<(), ConfigError> {
+        let info = self.rx.info;
+        let state = self.rx.state;
+        state.tx_rx_refcount.store(2, Ordering::Relaxed);
+
+        info.rcc.enable_and_reset();
+
+        info.regs.cr3().write(|w| {
+            w.set_rtse(self.rx.rts.is_some());
+            w.set_ctse(self.tx.cts.is_some());
+            #[cfg(not(any(usart_v1, usart_v2)))]
+            w.set_dem(self.tx.de.is_some());
+        });
+        configure(info, self.rx.kernel_clock, config, true, true)?;
+
+        info.interrupt.unpend();
+        unsafe { info.interrupt.enable() };
+
+        Ok(())
     }
 
     /// Perform a blocking write
diff --git a/embassy-stm32/src/usart/ringbuffered.rs b/embassy-stm32/src/usart/ringbuffered.rs
index f3a88b93f..8cf75933a 100644
--- a/embassy-stm32/src/usart/ringbuffered.rs
+++ b/embassy-stm32/src/usart/ringbuffered.rs
@@ -4,10 +4,12 @@ use core::sync::atomic::{compiler_fence, Ordering};
 use core::task::Poll;
 
 use embassy_embedded_hal::SetConfig;
+use embassy_hal_internal::PeripheralRef;
 use futures_util::future::{select, Either};
 
 use super::{clear_interrupt_flags, rdr, reconfigure, sr, Config, ConfigError, Error, Info, State, UartRx};
 use crate::dma::ReadableRingBuffer;
+use crate::gpio::{AnyPin, SealedPin as _};
 use crate::mode::Async;
 use crate::time::Hertz;
 use crate::usart::{Regs, Sr};
@@ -19,6 +21,8 @@ pub struct RingBufferedUartRx<'d> {
     info: &'static Info,
     state: &'static State,
     kernel_clock: Hertz,
+    rx: Option<PeripheralRef<'d, AnyPin>>,
+    rts: Option<PeripheralRef<'d, AnyPin>>,
     ring_buf: ReadableRingBuffer<'d, u8>,
 }
 
@@ -49,6 +53,8 @@ impl<'d> UartRx<'d, Async> {
         let state = self.state;
         let kernel_clock = self.kernel_clock;
         let ring_buf = unsafe { ReadableRingBuffer::new(rx_dma, request, rdr(info.regs), dma_buf, opts) };
+        let rx = unsafe { self.rx.as_ref().map(|x| x.clone_unchecked()) };
+        let rts = unsafe { self.rts.as_ref().map(|x| x.clone_unchecked()) };
 
         // Don't disable the clock
         mem::forget(self);
@@ -57,6 +63,8 @@ impl<'d> UartRx<'d, Async> {
             info,
             state,
             kernel_clock,
+            rx,
+            rts,
             ring_buf,
         }
     }
@@ -221,6 +229,8 @@ impl<'d> RingBufferedUartRx<'d> {
 impl Drop for RingBufferedUartRx<'_> {
     fn drop(&mut self) {
         self.teardown_uart();
+        self.rx.as_ref().map(|x| x.set_as_disconnected());
+        self.rts.as_ref().map(|x| x.set_as_disconnected());
         super::drop_tx_rx(self.info, self.state);
     }
 }