Serial flow control

Author: burrbull

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Added
 
+ - Serial flow control enable
  - `i2c_scanner` example [#758]
  - Enable `sdio` for stm32f446
  - port LTDC implementation and example from stm32f7xx-hal [#731]

src/gpio/alt.rs

@@ -335,10 +335,10 @@ pub trait SerialSync {
     type Ck;
 }
 /// Hardware flow control (RS232)
-pub trait SerialRs232 {
-    /// Receive
+pub trait SerialFlowControl {
+    /// "Clear To Send" blocks the data transmission at the end of the current transfer when high
     type Cts;
-    /// Transmit
+    /// "Request to send" indicates that the USART is ready to receive a data (when low)
     type Rts;
 }
 

src/gpio/alt/f4.rs

@@ -4047,7 +4047,7 @@ pub mod usart1 {
     impl SerialSync for USART {
         type Ck = Ck;
     }
-    impl SerialRs232 for USART {
+    impl SerialFlowControl for USART {
         type Cts = Cts;
         type Rts = Rts;
     }
@@ -4103,7 +4103,7 @@ pub mod usart2 {
     impl SerialSync for USART {
         type Ck = Ck;
     }
-    impl SerialRs232 for USART {
+    impl SerialFlowControl for USART {
         type Cts = Cts;
         type Rts = Rts;
     }
@@ -4182,7 +4182,7 @@ pub mod usart3 {
     impl SerialSync for USART {
         type Ck = Ck;
     }
-    impl SerialRs232 for USART {
+    impl SerialFlowControl for USART {
         type Cts = Cts;
         type Rts = Rts;
     }
@@ -4293,7 +4293,7 @@ pub mod usart6 {
         feature = "gpio-f446",
         feature = "gpio-f469"
     ))]
-    impl SerialRs232 for USART {
+    impl SerialFlowControl for USART {
         type Cts = Cts;
         type Rts = Rts;
     }
@@ -4355,7 +4355,7 @@ pub mod uart4 {
         type Tx<Otype> = Tx<Otype>;
     }
     #[cfg(feature = "gpio-f446")]
-    impl SerialRs232 for UART {
+    impl SerialFlowControl for UART {
         type Cts = Cts;
         type Rts = Rts;
     }
@@ -4416,7 +4416,7 @@ pub mod uart5 {
         type Tx<Otype> = Tx<Otype>;
     }
     #[cfg(feature = "gpio-f446")]
-    impl SerialRs232 for UART {
+    impl SerialFlowControl for UART {
         type Cts = Cts;
         type Rts = Rts;
     }

src/serial/uart_impls.rs

@@ -10,7 +10,10 @@ use crate::dma::{
     traits::{DMASet, PeriAddress},
     MemoryToPeripheral, PeripheralToMemory,
 };
-use crate::gpio::{alt::SerialAsync as CommonPins, NoPin, PushPull};
+use crate::gpio::{
+    alt::{SerialAsync as CommonPins, SerialFlowControl},
+    NoPin, PushPull,
+};
 use crate::rcc::{self, Clocks};
 
 #[cfg(feature = "uart4")]
@@ -266,6 +269,20 @@ macro_rules! uartCommon {
     };
 }
 
+pub trait RBFlowControlImpl {
+    fn enable_rts(&self, state: bool);
+    fn enable_cts(&self, state: bool);
+}
+
+impl RBFlowControlImpl for RegisterBlockUsart {
+    fn enable_rts(&self, state: bool) {
+        self.cr3().modify(|_, w| w.rtse().bit(state));
+    }
+    fn enable_cts(&self, state: bool) {
+        self.cr3().modify(|_, w| w.ctse().bit(state));
+    }
+}
+
 impl RegisterBlockImpl for RegisterBlockUsart {
     fn new<UART: Instance<RegisterBlock = Self>, WORD>(
         uart: UART,
@@ -406,6 +423,23 @@ where {
     uartCommon! {}
 }
 
+#[cfg(feature = "uart4")]
+#[cfg(not(any(
+    feature = "gpio-f413",
+    feature = "gpio-f417",
+    feature = "gpio-f427",
+    feature = "gpio-f446",
+    feature = "gpio-f469"
+)))]
+impl RBFlowControlImpl for RegisterBlockUart {
+    fn enable_rts(&self, state: bool) {
+        self.cr3().modify(|_, w| w.rtse().bit(state));
+    }
+    fn enable_cts(&self, state: bool) {
+        self.cr3().modify(|_, w| w.ctse().bit(state));
+    }
+}
+
 #[cfg(feature = "uart4")]
 impl RegisterBlockImpl for RegisterBlockUart {
     fn new<UART: Instance<RegisterBlock = Self>, WORD>(
@@ -513,6 +547,34 @@ where {
     uartCommon! {}
 }
 
+impl<UART: Instance + SerialFlowControl, WORD> Serial<UART, WORD>
+where
+    UART::RegisterBlock: RBFlowControlImpl,
+{
+    pub fn with_rts(self, rts: impl Into<UART::Rts>) -> Self {
+        self.rx.usart.enable_rts(true);
+        let _rts = rts.into();
+        self
+    }
+    pub fn with_cts(self, cts: impl Into<UART::Cts>) -> Self {
+        self.tx.usart.enable_cts(true);
+        let _cts = cts.into();
+        self
+    }
+    pub fn enable_request_to_send(&mut self) {
+        self.rx.usart.enable_rts(true);
+    }
+    pub fn disable_request_to_send(&mut self) {
+        self.rx.usart.enable_rts(false);
+    }
+    pub fn enable_clear_to_send(&mut self) {
+        self.tx.usart.enable_cts(true);
+    }
+    pub fn disable_clear_to_send(&mut self) {
+        self.tx.usart.enable_cts(false);
+    }
+}
+
 impl<UART: Instance, WORD> RxISR for Serial<UART, WORD>
 where
     Rx<UART, WORD>: RxISR,

src/uart.rs

@@ -16,7 +16,7 @@
 
 use crate::pac;
 
-use crate::serial::uart_impls::{RegisterBlockImpl, RegisterBlockUart};
+use crate::serial::uart_impls::RegisterBlockUart;
 
 pub use crate::serial::{config, Error, Event, Instance, NoRx, NoTx, Rx, RxISR, Serial, Tx, TxISR};
 pub use config::Config;