hil: uart: force baud rate to be nonzero

YoeDistro · Feb 26, 2025 · bea1b9b · bea1b9b
1 parent 24465d3
commit bea1b9b
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Showing 6 changed files with 15 additions and 17 deletions.
diff --git a/boards/components/src/debug_writer.rs b/boards/components/src/debug_writer.rs
@@ -29,7 +29,6 @@ use kernel::collections::ring_buffer::RingBuffer;
 use kernel::component::Component;
 use kernel::hil;
 use kernel::hil::uart;
-use kernel::hil::uart::BaudRate;
 
 // The sum of the output_buf and internal_buf is set to a multiple of 1024 bytes in order to avoid excessive
 // padding between kernel memory and application memory (which often needs to be aligned to at
@@ -185,7 +184,7 @@ impl<U: uart::Uart<'static> + uart::Transmit<'static> + 'static, const BUF_SIZE_
         }
 
         let _ = self.uart.configure(uart::Parameters {
-            baud_rate: U::BaudRate::from_nonzero(115200),
+            baud_rate: core::num::NonZeroU32::new(115200).unwrap().into(),
             width: uart::Width::Eight,
             stop_bits: uart::StopBits::One,
             parity: uart::Parity::None,

diff --git a/capsules/extra/src/nrf51822_serialization.rs b/capsules/extra/src/nrf51822_serialization.rs
@@ -29,7 +29,6 @@ use core::cmp;
 use kernel::grant::{AllowRoCount, AllowRwCount, Grant, UpcallCount};
 use kernel::hil;
 use kernel::hil::uart;
-use kernel::hil::uart::BaudRate;
 use kernel::processbuffer::{ReadableProcessBuffer, WriteableProcessBuffer};
 use kernel::syscall::{CommandReturn, SyscallDriver};
 use kernel::utilities::cells::{OptionalCell, TakeCell};
@@ -119,7 +118,7 @@ impl<'a, U: uart::UartAdvanced<'a>> Nrf51822Serialization<'a, U> {
 
     pub fn initialize(&self) {
         let _ = self.uart.configure(uart::Parameters {
-            baud_rate: U::BaudRate::from_nonzero(250000),
+            baud_rate: core::num::NonZeroU32::new(250000).unwrap().into(),
             width: uart::Width::Eight,
             stop_bits: uart::StopBits::One,
             parity: uart::Parity::Even,

diff --git a/capsules/extra/src/usb/cdc.rs b/capsules/extra/src/usb/cdc.rs
@@ -651,7 +651,7 @@ impl<'a, U: hil::usb::UsbController<'a>, A: 'a + Alarm<'a>> hil::usb::Client<'a>
 }
 
 impl<'a, U: hil::usb::UsbController<'a>, A: 'a + Alarm<'a>> uart::Configure for CdcAcm<'a, U, A> {
-    type BaudRate = ();
+    type BaudRate = uart::NonexistentBaudRate;
 
     fn configure(&self, _parameters: uart::Parameters<Self::BaudRate>) -> Result<(), ErrorCode> {
         // Since this is not a real UART, we don't need to consider these

diff --git a/chips/nrf52/src/uart.rs b/chips/nrf52/src/uart.rs
@@ -179,9 +179,9 @@ pub enum UarteBaudRate {
     Baud1000000,
 }
 
-impl uart::BaudRate for UarteBaudRate {
-    fn from_nonzero(baud_rate: u32) -> Self {
-        match baud_rate {
+impl From<core::num::NonZeroU32> for UarteBaudRate {
+    fn from(baud_rate: core::num::NonZeroU32) -> Self {
+        match baud_rate.get() {
             1200 => UarteBaudRate::Baud1200,
             2400 => UarteBaudRate::Baud2400,
             4800 => UarteBaudRate::Baud4800,

diff --git a/chips/segger/src/rtt.rs b/chips/segger/src/rtt.rs
@@ -335,7 +335,7 @@ impl<'a, A: hil::time::Alarm<'a>> hil::time::AlarmClient for SeggerRtt<'a, A> {
 // Dummy implementation so this can act as the underlying UART for a
 // virtualized UART MUX. -pal 1/10/19
 impl<'a, A: hil::time::Alarm<'a>> uart::Configure for SeggerRtt<'a, A> {
-    type BaudRate = ();
+    type BaudRate = uart::NonexistentBaudRate;
 
     fn configure(&self, _parameters: uart::Parameters<Self::BaudRate>) -> Result<(), ErrorCode> {
         Err(ErrorCode::FAIL)

diff --git a/kernel/src/hil/uart.rs b/kernel/src/hil/uart.rs
@@ -37,19 +37,19 @@ pub enum Width {
     Eight = 8,
 }
 
-pub trait BaudRate {
-    fn from_nonzero(baud_rate: u32) -> Self;
-}
+// pub trait BaudRate:  {}
 
-impl BaudRate for () {
-    fn from_nonzero(_baud_rate: u32) -> Self {
-        ()
+#[derive(Copy, Clone)]
+pub struct NonexistentBaudRate {}
+impl From<core::num::NonZeroU32> for NonexistentBaudRate {
+    fn from(_baud_rate: core::num::NonZeroU32) -> Self {
+        NonexistentBaudRate {}
     }
 }
 
 /// UART parameters for configuring the bus.
 #[derive(Copy, Clone, Debug)]
-pub struct Parameters<BaudRateType: BaudRate> {
+pub struct Parameters<BaudRateType: From<core::num::NonZeroU32> + Copy> {
     /// Baud rate in bit/s.
     pub baud_rate: BaudRateType,
     /// Number of bits per word.
@@ -120,7 +120,7 @@ impl<T: ReceiveClient + TransmitClient> Client for T {}
 
 /// Trait for configuring a UART.
 pub trait Configure {
-    type BaudRate: BaudRate + Copy;
+    type BaudRate: From<core::num::NonZeroU32> + Copy;
 
     /// Set the configuration parameters for the UART bus.
     ///