From ddab4c2841bb84591f66b18bc054e803a95b3d0a Mon Sep 17 00:00:00 2001
From: Mathieu David <mathieudavid@mathieudavid.org>
Date: Tue, 2 Jan 2024 16:48:40 +0100
Subject: [PATCH] Fix error "assigning to &T is undefined behavior" and clippy
 warnings

Since Rust 1.73.0, the compiler errors about assigning to a reference
when casting it to a mutable pointer.

See: https://doc.rust-lang.org/beta/rustc/lints/listing/deny-by-default.html#invalid-reference-casting
---
 src/exti.rs    | 8 ++++----
 src/gpio.rs    | 4 ++--
 src/prelude.rs | 2 +-
 src/serial.rs  | 5 +++--
 src/spi.rs     | 3 ++-
 5 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/src/exti.rs b/src/exti.rs
index dec7ad8..d3a0209 100755
--- a/src/exti.rs
+++ b/src/exti.rs
@@ -69,7 +69,7 @@ impl Exti {
 
         unsafe {
             match line {
-                0 | 1 | 2 | 3 => {
+                0..=3 => {
                     syscfg.syscfg.exticr1.modify(|_, w| match line {
                         0 => w.exti0().bits(port_bm),
                         1 => w.exti1().bits(port_bm),
@@ -78,7 +78,7 @@ impl Exti {
                         _ => w,
                     });
                 }
-                4 | 5 | 6 | 7 => {
+                4..=7 => {
                     // no need to assert that PH is not port,
                     // since line is assert on port above
                     syscfg.syscfg.exticr2.modify(|_, w| match line {
@@ -89,7 +89,7 @@ impl Exti {
                         _ => w,
                     });
                 }
-                8 | 9 | 10 | 11 => {
+                8..=11 => {
                     syscfg.syscfg.exticr3.modify(|_, w| match line {
                         8 => w.exti8().bits(port_bm),
                         9 => w.exti9().bits(port_bm),
@@ -98,7 +98,7 @@ impl Exti {
                         _ => w,
                     });
                 }
-                12 | 13 | 14 | 15 => {
+                12..=15 => {
                     syscfg.syscfg.exticr4.modify(|_, w| match line {
                         12 => w.exti12().bits(port_bm),
                         13 => w.exti13().bits(port_bm),
diff --git a/src/gpio.rs b/src/gpio.rs
index 10e1eb9..a99b73e 100755
--- a/src/gpio.rs
+++ b/src/gpio.rs
@@ -487,9 +487,9 @@ macro_rules! gpio {
                     pub fn set_speed(self, speed: Speed) -> Self {
                         let offset = 2 * $i;
                         unsafe {
-                            &(*$GPIOX::ptr()).ospeedr.modify(|r, w| {
+                            let _ = &(*$GPIOX::ptr()).ospeedr.modify(|r, w| {
                                 w.bits((r.bits() & !(0b11 << offset)) | ((speed as u32) << offset))
-                            })
+                            });
                         };
                         self
                     }
diff --git a/src/prelude.rs b/src/prelude.rs
index b6812b2..68ea6f7 100755
--- a/src/prelude.rs
+++ b/src/prelude.rs
@@ -41,5 +41,5 @@ pub use crate::serial::{Serial1Ext as _, Serial1LpExt as _};
     feature = "io-STM32L071",
 ))]
 pub use crate::serial::{Serial1LpExt as _, Serial2Ext as _};
-#[cfg(any(feature = "io-STM32L071",))]
+#[cfg(feature = "io-STM32L071")]
 pub use crate::serial::{Serial4Ext as _, Serial5Ext as _};
diff --git a/src/serial.rs b/src/serial.rs
index ca2da9f..ab088d9 100755
--- a/src/serial.rs
+++ b/src/serial.rs
@@ -1,6 +1,7 @@
 use core::fmt;
 use core::marker::PhantomData;
 use core::ptr;
+use core::cell::UnsafeCell;
 
 use nb::block;
 
@@ -33,7 +34,7 @@ use crate::dma::Buffer;
 ))]
 use crate::gpio::gpioc::*;
 use crate::gpio::{gpioa::*, gpiob::*};
-#[cfg(any(feature = "io-STM32L071"))]
+#[cfg(feature = "io-STM32L071")]
 use crate::gpio::{gpiod::*, gpioe::*};
 
 /// Serial error
@@ -661,7 +662,7 @@ macro_rules! usart {
                     if isr.txe().bit_is_set() {
                         // NOTE(unsafe) atomic write to stateless register
                         // NOTE(write_volatile) 8-bit write that's not possible through the svd2rust API
-                        unsafe { ptr::write_volatile(&(*$USARTX::ptr()).tdr as *const _ as *mut _, byte) }
+                        unsafe { ptr::write_volatile(UnsafeCell::raw_get(&(*$USARTX::ptr()).tdr as *const _ as _), byte) }
 
                         Ok(())
                     } else {
diff --git a/src/spi.rs b/src/spi.rs
index 7b3dd9f..f5e7694 100755
--- a/src/spi.rs
+++ b/src/spi.rs
@@ -3,6 +3,7 @@ use core::{
     ops::{Deref, DerefMut},
     pin::Pin,
     ptr,
+    cell::UnsafeCell,
 };
 
 use as_slice::{AsMutSlice, AsSlice};
@@ -449,7 +450,7 @@ macro_rules! spi {
                         nb::Error::Other(Error::Crc)
                     } else if sr.txe().bit_is_set() {
                         // NOTE(write_volatile) see note above
-                        unsafe { ptr::write_volatile(&self.spi.dr as *const _ as *mut u8, byte) }
+                        unsafe { ptr::write_volatile(UnsafeCell::raw_get(&self.spi.dr as *const _ as _), byte) }
                         return Ok(());
                     } else {
                         nb::Error::WouldBlock