Unlike STM32G0, STM32G4 supports FIFOs for all UARTs, including the LPUART.

This code modifies the configuration structs accordingly and removes the
Config type parameter, as it did not have any real use anyways.

Author: Mathias Gottschlag

src/serial/config.rs

@@ -55,12 +55,17 @@ impl FifoThreshold {
     }
 }
 #[derive(PartialEq, PartialOrd, Clone, Copy)]
-pub struct BasicConfig {
+pub struct LowPowerConfig {
     pub(crate) baudrate: Bps,
     pub(crate) wordlength: WordLength,
     pub(crate) parity: Parity,
     pub(crate) stopbits: StopBits,
     pub(crate) swap: bool,
+    pub(crate) fifo_enable: bool,
+    pub(crate) tx_fifo_threshold: FifoThreshold,
+    pub(crate) rx_fifo_threshold: FifoThreshold,
+    pub(crate) tx_fifo_interrupt: bool,
+    pub(crate) rx_fifo_interrupt: bool,
 }
 
 #[derive(PartialEq, PartialOrd, Clone, Copy)]
@@ -79,7 +84,7 @@ pub struct FullConfig {
     pub(crate) receiver_timeout: Option<u32>,
 }
 
-impl BasicConfig {
+impl LowPowerConfig {
     pub fn baudrate(mut self, baudrate: Bps) -> Self {
         self.baudrate = baudrate;
         self
@@ -122,6 +127,31 @@ impl BasicConfig {
         self.swap = true;
         self
     }
+
+    pub fn fifo_enable(mut self) -> Self {
+        self.fifo_enable = true;
+        self
+    }
+
+    pub fn tx_fifo_threshold(mut self, threshold: FifoThreshold) -> Self {
+        self.tx_fifo_threshold = threshold;
+        self
+    }
+
+    pub fn rx_fifo_threshold(mut self, threshold: FifoThreshold) -> Self {
+        self.rx_fifo_threshold = threshold;
+        self
+    }
+
+    pub fn tx_fifo_enable_interrupt(mut self) -> Self {
+        self.tx_fifo_interrupt = true;
+        self
+    }
+
+    pub fn rx_fifo_enable_interrupt(mut self) -> Self {
+        self.rx_fifo_interrupt = true;
+        self
+    }
 }
 
 impl FullConfig {
@@ -204,15 +234,20 @@ impl FullConfig {
 #[derive(Debug)]
 pub struct InvalidConfig;
 
-impl Default for BasicConfig {
-    fn default() -> BasicConfig {
+impl Default for LowPowerConfig {
+    fn default() -> LowPowerConfig {
         let baudrate = 19_200.bps();
-        BasicConfig {
+        LowPowerConfig {
             baudrate,
             wordlength: WordLength::DataBits8,
             parity: Parity::ParityNone,
             stopbits: StopBits::STOP1,
             swap: false,
+            fifo_enable: false,
+            tx_fifo_threshold: FifoThreshold::FIFO_8_BYTES,
+            rx_fifo_threshold: FifoThreshold::FIFO_8_BYTES,
+            tx_fifo_interrupt: false,
+            rx_fifo_interrupt: false,
         }
     }
 }

src/serial/mod.rs

@@ -1,3 +1,13 @@
+//! UART serial port support.
+//!
+//! This module provides support for asynchronous communication using UARTs/USARTs/LPUARTs in
+//! configurations without hardware flow control. Correct usage is shown by the `uart`,
+//! `uart-fifo`, and `uart-dma` examples.
+//!
+//! **Note that the APB clock needs to be at least 16 times faster than the UART baud rate for all
+//! UARTs except for the LPUART.** The latter contains an internal 256x clock multiplier.
+//!
+//! Most of this code was originally taken from `stm32g0xx-hal`.
 pub mod config;
 pub mod usart;