Merge #509

509: Remove unsafe from nRF uarte and improve doco with rationale r=Dirbaio a=huntc

The constructors themselves are not strictly unsafe. Interactions with DMA can be generally unsafe if a future is dropped, but that's a separate issue. It is important that we use the `unsafe` keyword diligently as it can lead to confusion otherwise.

I've also provided some rationale re. the usage of [Uarte] vs [BufferedUarte].

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

2 files changed, 16 insertions, 19 deletions

diff --git a/examples/nrf/src/bin/buffered_uart.rs b/examples/nrf/src/bin/buffered_uart.rs
index 90d288780..5d9075edf 100644
--- a/examples/nrf/src/bin/buffered_uart.rs
+++ b/examples/nrf/src/bin/buffered_uart.rs
@@ -24,23 +24,21 @@ async fn main(_spawner: Spawner, p: Peripherals) {
 
     let irq = interrupt::take!(UARTE0_UART0);
     let mut state = State::new();
-    let u = unsafe {
-        BufferedUarte::new(
-            &mut state,
-            p.UARTE0,
-            p.TIMER0,
-            p.PPI_CH0,
-            p.PPI_CH1,
-            irq,
-            p.P0_08,
-            p.P0_06,
-            NoPin,
-            NoPin,
-            config,
-            &mut rx_buffer,
-            &mut tx_buffer,
-        )
-    };
+    let u = BufferedUarte::new(
+        &mut state,
+        p.UARTE0,
+        p.TIMER0,
+        p.PPI_CH0,
+        p.PPI_CH1,
+        irq,
+        p.P0_08,
+        p.P0_06,
+        NoPin,
+        NoPin,
+        config,
+        &mut rx_buffer,
+        &mut tx_buffer,
+    );
     pin_mut!(u);
 
     info!("uarte initialized!");
diff --git a/examples/nrf/src/bin/uart.rs b/examples/nrf/src/bin/uart.rs
index 6b89e083d..208961c8b 100644
--- a/examples/nrf/src/bin/uart.rs
+++ b/examples/nrf/src/bin/uart.rs
@@ -18,8 +18,7 @@ async fn main(_spawner: Spawner, p: Peripherals) {
     config.baudrate = uarte::Baudrate::BAUD115200;
 
     let irq = interrupt::take!(UARTE0_UART0);
-    let mut uart =
-        unsafe { uarte::Uarte::new(p.UARTE0, irq, p.P0_08, p.P0_06, NoPin, NoPin, config) };
+    let mut uart = uarte::Uarte::new(p.UARTE0, irq, p.P0_08, p.P0_06, NoPin, NoPin, config);
 
     info!("uarte initialized!");