Merge #987

987: (embassy-stm32): uart flowcontrol r=Dirbaio a=MathiasKoch

Add RTS & CTS flow control to stm32 UARTs

Co-authored-by: Mathias <[email protected]>

1 files changed, 39 insertions, 2 deletions

diff --git a/embassy-stm32/src/usart/mod.rs b/embassy-stm32/src/usart/mod.rs
index a152a0c15..3f5b99523 100644
--- a/embassy-stm32/src/usart/mod.rs
+++ b/embassy-stm32/src/usart/mod.rs
@@ -222,10 +222,48 @@ impl<'d, T: BasicInstance, TxDma, RxDma> Uart<'d, T, TxDma, RxDma> {
         rx_dma: impl Peripheral<P = RxDma> + 'd,
         config: Config,
     ) -> Self {
-        into_ref!(_inner, rx, tx, tx_dma, rx_dma);
+        T::enable();
+        T::reset();
+
+        Self::new_inner(_inner, rx, tx, tx_dma, rx_dma, config)
+    }
+
+    pub fn new_with_rtscts(
+        _inner: impl Peripheral<P = T> + 'd,
+        rx: impl Peripheral<P = impl RxPin<T>> + 'd,
+        tx: impl Peripheral<P = impl TxPin<T>> + 'd,
+        rts: impl Peripheral<P = impl RtsPin<T>> + 'd,
+        cts: impl Peripheral<P = impl CtsPin<T>> + 'd,
+        tx_dma: impl Peripheral<P = TxDma> + 'd,
+        rx_dma: impl Peripheral<P = RxDma> + 'd,
+        config: Config,
+    ) -> Self {
+        into_ref!(cts, rts);
 
         T::enable();
         T::reset();
+
+        unsafe {
+            rts.set_as_af(rts.af_num(), AFType::OutputPushPull);
+            cts.set_as_af(cts.af_num(), AFType::Input);
+            T::regs().cr3().write(|w| {
+                w.set_rtse(true);
+                w.set_ctse(true);
+            });
+        }
+        Self::new_inner(_inner, rx, tx, tx_dma, rx_dma, config)
+    }
+
+    fn new_inner(
+        _inner: impl Peripheral<P = T> + 'd,
+        rx: impl Peripheral<P = impl RxPin<T>> + 'd,
+        tx: impl Peripheral<P = impl TxPin<T>> + 'd,
+        tx_dma: impl Peripheral<P = TxDma> + 'd,
+        rx_dma: impl Peripheral<P = RxDma> + 'd,
+        config: Config,
+    ) -> Self {
+        into_ref!(_inner, rx, tx, tx_dma, rx_dma);
+
         let pclk_freq = T::frequency();
 
         // TODO: better calculation, including error checking and OVER8 if possible.
@@ -238,7 +276,6 @@ impl<'d, T: BasicInstance, TxDma, RxDma> Uart<'d, T, TxDma, RxDma> {
             tx.set_as_af(tx.af_num(), AFType::OutputPushPull);
 
             r.cr2().write(|_w| {});
-            r.cr3().write(|_w| {});
             r.brr().write_value(regs::Brr(div));
             r.cr1().write(|w| {
                 w.set_ue(true);