Get rid of some warnings

40 files changed, 182 insertions, 216 deletions

diff --git a/embassy-macros/src/lib.rs b/embassy-macros/src/lib.rs
index 23f1cda99..0708b17ef 100644
--- a/embassy-macros/src/lib.rs
+++ b/embassy-macros/src/lib.rs
@@ -3,7 +3,7 @@
 extern crate proc_macro;
 
 use darling::FromMeta;
-use proc_macro::{Diagnostic, Level, Span, TokenStream};
+use proc_macro::{Span, TokenStream};
 use quote::{format_ident, quote};
 use syn::spanned::Spanned;
 
@@ -39,7 +39,7 @@ pub fn task(args: TokenStream, item: TokenStream) -> TokenStream {
             .emit();
         fail = true;
     }
-    if task_fn.sig.generics.params.len() != 0 {
+    if !task_fn.sig.generics.params.is_empty() {
         task_fn
             .sig
             .span()
diff --git a/embassy-nrf-examples/src/bin/buffered_uart.rs b/embassy-nrf-examples/src/bin/buffered_uart.rs
index 7c7283fc2..84bc742f3 100644
--- a/embassy-nrf-examples/src/bin/buffered_uart.rs
+++ b/embassy-nrf-examples/src/bin/buffered_uart.rs
@@ -66,9 +66,7 @@ async fn run() {
 
         // Reverse buf
         for i in 0..4 {
-            let tmp = buf[i];
-            buf[i] = buf[7 - i];
-            buf[7 - i] = tmp;
+            buf.swap(i, 7 - i);
         }
 
         info!("writing...");
diff --git a/embassy-nrf-examples/src/bin/gpiote_channel.rs b/embassy-nrf-examples/src/bin/gpiote_channel.rs
index 5470c47cd..4c4dabc6d 100644
--- a/embassy-nrf-examples/src/bin/gpiote_channel.rs
+++ b/embassy-nrf-examples/src/bin/gpiote_channel.rs
@@ -12,7 +12,7 @@ use nrf52840_hal::gpio;
 
 use embassy::executor::{task, Executor};
 use embassy::util::Forever;
-use embassy_nrf::gpiote::{Channels, Gpiote, InputChannel, InputChannelPolarity};
+use embassy_nrf::gpiote::{Gpiote, InputChannel, InputChannelPolarity};
 use embassy_nrf::interrupt;
 
 #[task]
diff --git a/embassy-nrf-examples/src/bin/gpiote_port.rs b/embassy-nrf-examples/src/bin/gpiote_port.rs
index 9d999f951..0f1637faf 100644
--- a/embassy-nrf-examples/src/bin/gpiote_port.rs
+++ b/embassy-nrf-examples/src/bin/gpiote_port.rs
@@ -6,7 +6,6 @@
 mod example_common;
 use example_common::*;
 
-use core::mem;
 use core::pin::Pin;
 use cortex_m_rt::entry;
 use defmt::panic;
diff --git a/embassy-nrf-examples/src/bin/multiprio.rs b/embassy-nrf-examples/src/bin/multiprio.rs
index 8c2ec19af..89c285fa5 100644
--- a/embassy-nrf-examples/src/bin/multiprio.rs
+++ b/embassy-nrf-examples/src/bin/multiprio.rs
@@ -61,7 +61,6 @@
 mod example_common;
 use example_common::*;
 
-use cortex_m::peripheral::NVIC;
 use cortex_m_rt::entry;
 use defmt::panic;
 use nrf52840_hal::clocks;
diff --git a/embassy-nrf-examples/src/bin/qspi.rs b/embassy-nrf-examples/src/bin/qspi.rs
index 4edbd3f91..39326fa00 100644
--- a/embassy-nrf-examples/src/bin/qspi.rs
+++ b/embassy-nrf-examples/src/bin/qspi.rs
@@ -7,7 +7,7 @@ mod example_common;
 use example_common::*;
 
 use cortex_m_rt::entry;
-use defmt::{assert_eq, panic, *};
+use defmt::{assert_eq, panic};
 use nrf52840_hal::gpio;
 
 use embassy::executor::{task, Executor};
diff --git a/embassy-nrf-examples/src/bin/rtc_async.rs b/embassy-nrf-examples/src/bin/rtc_async.rs
index 5260c69a8..5fb68633e 100644
--- a/embassy-nrf-examples/src/bin/rtc_async.rs
+++ b/embassy-nrf-examples/src/bin/rtc_async.rs
@@ -6,11 +6,10 @@
 mod example_common;
 use example_common::*;
 
-use core::mem::MaybeUninit;
 use cortex_m_rt::entry;
 use defmt::panic;
 use embassy::executor::{task, Executor};
-use embassy::time::{Clock, Duration, Timer};
+use embassy::time::{Duration, Timer};
 use embassy::util::Forever;
 use embassy_nrf::pac;
 use embassy_nrf::{interrupt, rtc};
diff --git a/embassy-nrf-examples/src/bin/uart.rs b/embassy-nrf-examples/src/bin/uart.rs
index c5468d32b..8b540fca9 100644
--- a/embassy-nrf-examples/src/bin/uart.rs
+++ b/embassy-nrf-examples/src/bin/uart.rs
@@ -75,7 +75,7 @@ async fn run(uart: pac::UARTE0, port: pac::P0) {
         };
         let received = &mut buf[..received_len];
 
-        if received.len() > 0 {
+        if !received.is_empty() {
             info!("read done, got {:[u8]}", received);
 
             // Echo back received data
diff --git a/embassy-nrf/src/buffered_uarte.rs b/embassy-nrf/src/buffered_uarte.rs
index c61d111f0..d1908cf09 100644
--- a/embassy-nrf/src/buffered_uarte.rs
+++ b/embassy-nrf/src/buffered_uarte.rs
@@ -20,10 +20,7 @@ use crate::interrupt::{self, OwnedInterrupt};
 use crate::pac;
 use crate::util::peripheral::{PeripheralMutex, PeripheralState};
 use crate::util::ring_buffer::RingBuffer;
-use crate::{
-    fmt::{panic, todo, *},
-    util::low_power_wait_until,
-};
+use crate::{fmt::*, util::low_power_wait_until};
 
 // Re-export SVD variants to allow user to directly set values
 pub use crate::hal::uarte::Pins;
@@ -257,7 +254,7 @@ impl<'a, U: Instance, T: TimerInstance, P1: ConfigurablePpi, P2: ConfigurablePpi
 
             // We have data ready in buffer? Return it.
             let buf = state.rx.pop_buf();
-            if buf.len() != 0 {
+            if !buf.is_empty() {
                 trace!("  got {:?} {:?}", buf.as_ptr() as u32, buf.len());
                 let buf: &[u8] = buf;
                 let buf: &[u8] = unsafe { mem::transmute(buf) };
@@ -287,7 +284,7 @@ impl<'a, U: Instance, T: TimerInstance, P1: ConfigurablePpi, P2: ConfigurablePpi
             trace!("poll_write: {:?}", buf.len());
 
             let tx_buf = state.tx.push_buf();
-            if tx_buf.len() == 0 {
+            if tx_buf.is_empty() {
                 trace!("poll_write: pending");
                 state.tx_waker.register(cx.waker());
                 return Poll::Pending;
@@ -343,7 +340,7 @@ impl<'a, U: Instance, T: TimerInstance, P1: ConfigurablePpi, P2: ConfigurablePpi
                     trace!("  irq_rx: in state idle");
 
                     let buf = self.rx.push_buf();
-                    if buf.len() != 0 {
+                    if !buf.is_empty() {
                         trace!("  irq_rx: starting {:?}", buf.len());
                         self.rx_state = RxState::Receiving;
 
@@ -394,7 +391,7 @@ impl<'a, U: Instance, T: TimerInstance, P1: ConfigurablePpi, P2: ConfigurablePpi
                 TxState::Idle => {
                     trace!("  irq_tx: in state Idle");
                     let buf = self.tx.pop_buf();
-                    if buf.len() != 0 {
+                    if !buf.is_empty() {
                         trace!("  irq_tx: starting {:?}", buf.len());
                         self.tx_state = TxState::Transmitting(buf.len());
 
diff --git a/embassy-nrf/src/fmt.rs b/embassy-nrf/src/fmt.rs
index 4da69766c..1be1057a7 100644
--- a/embassy-nrf/src/fmt.rs
+++ b/embassy-nrf/src/fmt.rs
@@ -1,4 +1,5 @@
 #![macro_use]
+#![allow(clippy::module_inception)]
 
 #[cfg(all(feature = "defmt", feature = "log"))]
 compile_error!("You may not enable both `defmt` and `log` features.");
diff --git a/embassy-nrf/src/gpiote.rs b/embassy-nrf/src/gpiote.rs
index 89aab5bc6..0e48a7164 100644
--- a/embassy-nrf/src/gpiote.rs
+++ b/embassy-nrf/src/gpiote.rs
@@ -7,7 +7,6 @@ use core::task::{Context, Poll};
 use embassy::gpio::{WaitForHigh, WaitForLow};
 use embassy::util::Signal;
 
-use crate::fmt::{panic, *};
 use crate::hal::gpio::{Input, Level, Output, Pin as GpioPin, Port};
 use crate::interrupt;
 use crate::interrupt::OwnedInterrupt;
@@ -141,10 +140,10 @@ impl Gpiote {
     unsafe fn on_irq(_ctx: *mut ()) {
         let g = &*GPIOTE::ptr();
 
-        for i in 0..8 {
-            if g.events_in[i].read().bits() != 0 {
-                g.events_in[i].write(|w| w);
-                CHANNEL_SIGNALS[i].signal(());
+        for (event_in, signal) in g.events_in.iter().zip(CHANNEL_SIGNALS.iter()) {
+            if event_in.read().bits() != 0 {
+                event_in.write(|w| w);
+                signal.signal(());
             }
         }
 
diff --git a/embassy-nrf/src/qspi.rs b/embassy-nrf/src/qspi.rs
index 753a5985b..a93b5e891 100644
--- a/embassy-nrf/src/qspi.rs
+++ b/embassy-nrf/src/qspi.rs
@@ -1,9 +1,9 @@
-use crate::fmt::{assert, assert_eq, panic, *};
+use crate::fmt::{assert, assert_eq, *};
 use core::future::Future;
 
 use crate::hal::gpio::{Output, Pin as GpioPin, Port as GpioPort, PushPull};
 use crate::interrupt::{OwnedInterrupt, QSPIInterrupt};
-use crate::pac::{Interrupt, QSPI};
+use crate::pac::QSPI;
 
 pub use crate::pac::qspi::ifconfig0::ADDRMODE_A as AddressMode;
 pub use crate::pac::qspi::ifconfig0::PPSIZE_A as WritePageSize;
@@ -156,7 +156,7 @@ impl Qspi {
     pub fn sleep(&mut self) {
         info!("flash: sleeping");
         info!("flash: state = {:?}", self.inner.status.read().bits());
-        self.inner.ifconfig1.modify(|r, w| w.dpmen().enter());
+        self.inner.ifconfig1.modify(|_, w| w.dpmen().enter());
         info!("flash: state = {:?}", self.inner.status.read().bits());
         cortex_m::asm::delay(1000000);
         info!("flash: state = {:?}", self.inner.status.read().bits());
@@ -166,68 +166,66 @@ impl Qspi {
             .write(|w| w.tasks_deactivate().set_bit());
     }
 
-    pub fn custom_instruction<'a>(
+    pub async fn custom_instruction<'a>(
         &'a mut self,
         opcode: u8,
         req: &'a [u8],
         resp: &'a mut [u8],
-    ) -> impl Future<Output = Result<(), Error>> + 'a {
-        async move {
-            let bomb = DropBomb::new();
+    ) -> Result<(), Error> {
+        let bomb = DropBomb::new();
 
-            assert!(req.len() <= 8);
-            assert!(resp.len() <= 8);
+        assert!(req.len() <= 8);
+        assert!(resp.len() <= 8);
 
-            let mut dat0: u32 = 0;
-            let mut dat1: u32 = 0;
+        let mut dat0: u32 = 0;
+        let mut dat1: u32 = 0;
 
-            for i in 0..4 {
-                if i < req.len() {
-                    dat0 |= (req[i] as u32) << (i * 8);
-                }
+        for i in 0..4 {
+            if i < req.len() {
+                dat0 |= (req[i] as u32) << (i * 8);
             }
-            for i in 0..4 {
-                if i + 4 < req.len() {
-                    dat1 |= (req[i + 4] as u32) << (i * 8);
-                }
+        }
+        for i in 0..4 {
+            if i + 4 < req.len() {
+                dat1 |= (req[i + 4] as u32) << (i * 8);
             }
+        }
 
-            let len = core::cmp::max(req.len(), resp.len()) as u8;
-
-            self.inner.cinstrdat0.write(|w| unsafe { w.bits(dat0) });
-            self.inner.cinstrdat1.write(|w| unsafe { w.bits(dat1) });
-            self.inner.events_ready.reset();
-            self.inner.cinstrconf.write(|w| {
-                let w = unsafe { w.opcode().bits(opcode) };
-                let w = unsafe { w.length().bits(len + 1) };
-                let w = w.lio2().bit(true);
-                let w = w.lio3().bit(true);
-                let w = w.wipwait().bit(true);
-                let w = w.wren().bit(true);
-                let w = w.lfen().bit(false);
-                let w = w.lfstop().bit(false);
-                w
-            });
+        let len = core::cmp::max(req.len(), resp.len()) as u8;
+
+        self.inner.cinstrdat0.write(|w| unsafe { w.bits(dat0) });
+        self.inner.cinstrdat1.write(|w| unsafe { w.bits(dat1) });
+        self.inner.events_ready.reset();
+        self.inner.cinstrconf.write(|w| {
+            let w = unsafe { w.opcode().bits(opcode) };
+            let w = unsafe { w.length().bits(len + 1) };
+            let w = w.lio2().bit(true);
+            let w = w.lio3().bit(true);
+            let w = w.wipwait().bit(true);
+            let w = w.wren().bit(true);
+            let w = w.lfen().bit(false);
+            let w = w.lfstop().bit(false);
+            w
+        });
 
-            SIGNAL.wait().await;
+        SIGNAL.wait().await;
 
-            let dat0 = self.inner.cinstrdat0.read().bits();
-            let dat1 = self.inner.cinstrdat1.read().bits();
-            for i in 0..4 {
-                if i < resp.len() {
-                    resp[i] = (dat0 >> (i * 8)) as u8;
-                }
+        let dat0 = self.inner.cinstrdat0.read().bits();
+        let dat1 = self.inner.cinstrdat1.read().bits();
+        for i in 0..4 {
+            if i < resp.len() {
+                resp[i] = (dat0 >> (i * 8)) as u8;
             }
-            for i in 0..4 {
-                if i + 4 < resp.len() {
-                    resp[i] = (dat1 >> (i * 8)) as u8;
-                }
+        }
+        for i in 0..4 {
+            if i + 4 < resp.len() {
+                resp[i] = (dat1 >> (i * 8)) as u8;
             }
+        }
 
-            bomb.defuse();
+        bomb.defuse();
 
-            Ok(())
-        }
+        Ok(())
     }
 }
 
diff --git a/embassy-nrf/src/rtc.rs b/embassy-nrf/src/rtc.rs
index dde0fd4ca..616254025 100644
--- a/embassy-nrf/src/rtc.rs
+++ b/embassy-nrf/src/rtc.rs
@@ -4,7 +4,6 @@ use core::sync::atomic::{AtomicU32, Ordering};
 
 use embassy::time::Clock;
 
-use crate::fmt::*;
 use crate::interrupt;
 use crate::interrupt::{CriticalSection, Mutex, OwnedInterrupt};
 use crate::pac::rtc0;
@@ -19,6 +18,7 @@ fn compare_n(n: usize) -> u32 {
     1 << (n + 16)
 }
 
+#[cfg(tests)]
 mod test {
     use super::*;
 
@@ -159,7 +159,9 @@ impl<T: Instance> RTC<T> {
         alarm.timestamp.set(u64::MAX);
 
         // Call after clearing alarm, so the callback can set another alarm.
-        alarm.callback.get().map(|(f, ctx)| f(ctx));
+        if let Some((f, ctx)) = alarm.callback.get() {
+            f(ctx);
+        }
     }
 
     fn set_alarm_callback(&self, n: usize, callback: fn(*mut ()), ctx: *mut ()) {
diff --git a/embassy-nrf/src/util/peripheral.rs b/embassy-nrf/src/util/peripheral.rs
index 1cc04f4ab..fee343d90 100644
--- a/embassy-nrf/src/util/peripheral.rs
+++ b/embassy-nrf/src/util/peripheral.rs
@@ -68,7 +68,7 @@ impl<S: PeripheralState> PeripheralMutex<S> {
 
 impl<S: PeripheralState> Drop for PeripheralMutex<S> {
     fn drop(&mut self) {
-        if let Some((state, irq)) = &mut self.inner {
+        if let Some((_state, irq)) = &mut self.inner {
             irq.disable();
             irq.remove_handler();
         }
diff --git a/embassy-nrf/src/util/ring_buffer.rs b/embassy-nrf/src/util/ring_buffer.rs
index f395785a5..f2b9f7359 100644
--- a/embassy-nrf/src/util/ring_buffer.rs
+++ b/embassy-nrf/src/util/ring_buffer.rs
@@ -1,4 +1,4 @@
-use crate::fmt::{assert, panic, todo, *};
+use crate::fmt::{assert, *};
 
 pub struct RingBuffer<'a> {
     buf: &'a mut [u8],
diff --git a/embassy-std-examples/src/bin/serial.rs b/embassy-std-examples/src/bin/serial.rs
index b66b7de20..cad64fb2f 100644
--- a/embassy-std-examples/src/bin/serial.rs
+++ b/embassy-std-examples/src/bin/serial.rs
@@ -5,7 +5,7 @@ mod serial_port;
 
 use async_io::Async;
 use embassy::executor::task;
-use embassy::io::{AsyncBufRead, AsyncBufReadExt, AsyncWrite, AsyncWriteExt};
+use embassy::io::AsyncBufReadExt;
 use embassy::util::Forever;
 use embassy_std::Executor;
 use log::*;
diff --git a/embassy-stm32f4-examples/src/bin/exti.rs b/embassy-stm32f4-examples/src/bin/exti.rs
index ec4490b16..79348777d 100644
--- a/embassy-stm32f4-examples/src/bin/exti.rs
+++ b/embassy-stm32f4-examples/src/bin/exti.rs
@@ -7,25 +7,20 @@
 mod example_common;
 use example_common::{panic, *};
 
-use cortex_m::singleton;
 use cortex_m_rt::entry;
 use embassy::executor::{task, Executor};
 use embassy::gpio::*;
 use embassy::util::Forever;
 use embassy_stm32f4::exti;
-use embassy_stm32f4::exti::*;
 use embassy_stm32f4::interrupt;
-use embassy_stm32f4::serial;
 use futures::pin_mut;
-use stm32f4xx_hal::serial::config::Config;
+use stm32f4xx_hal::prelude::*;
 use stm32f4xx_hal::stm32;
-use stm32f4xx_hal::syscfg;
-use stm32f4xx_hal::{prelude::*, serial::config};
 
 static EXTI: Forever<exti::ExtiManager> = Forever::new();
 
 #[task]
-async fn run(dp: stm32::Peripherals, cp: cortex_m::Peripherals) {
+async fn run(dp: stm32::Peripherals, _cp: cortex_m::Peripherals) {
     let gpioa = dp.GPIOA.split();
 
     let button = gpioa.pa0.into_pull_up_input();
diff --git a/embassy-stm32f4-examples/src/bin/hello.rs b/embassy-stm32f4-examples/src/bin/hello.rs
index 706501e35..d62378712 100644
--- a/embassy-stm32f4-examples/src/bin/hello.rs
+++ b/embassy-stm32f4-examples/src/bin/hello.rs
@@ -5,18 +5,10 @@
 
 #[path = "../example_common.rs"]
 mod example_common;
-use example_common::{panic, *};
+use example_common::*;
 
-use cortex_m::singleton;
 use cortex_m_rt::entry;
-use embassy::executor::{task, Executor};
-use embassy::uart::Uart;
-use embassy::util::Forever;
-use embassy_stm32f4::interrupt;
-use embassy_stm32f4::serial;
-use stm32f4xx_hal::serial::config::Config;
-use stm32f4xx_hal::stm32;
-use stm32f4xx_hal::{prelude::*, serial::config};
+use stm32f4xx_hal::prelude::*;
 
 #[entry]
 fn main() -> ! {
diff --git a/embassy-stm32f4-examples/src/bin/serial.rs b/embassy-stm32f4-examples/src/bin/serial.rs
index 7338d4fe0..f8e7f7f48 100644
--- a/embassy-stm32f4-examples/src/bin/serial.rs
+++ b/embassy-stm32f4-examples/src/bin/serial.rs
@@ -14,12 +14,12 @@ use embassy::uart::Uart;
 use embassy::util::Forever;
 use embassy_stm32f4::interrupt;
 use embassy_stm32f4::serial;
+use stm32f4xx_hal::prelude::*;
 use stm32f4xx_hal::serial::config::Config;
 use stm32f4xx_hal::stm32;
-use stm32f4xx_hal::{prelude::*, serial::config};
 
 #[task]
-async fn run(dp: stm32::Peripherals, cp: cortex_m::Peripherals) {
+async fn run(dp: stm32::Peripherals, _cp: cortex_m::Peripherals) {
     // https://gist.github.com/thalesfragoso/a07340c5df6eee3b04c42fdc69ecdcb1
     let gpioa = dp.GPIOA.split();
     let rcc = dp.RCC.constrain();
diff --git a/embassy-stm32f4/src/exti.rs b/embassy-stm32f4/src/exti.rs
index 9b722374c..bf9cc582f 100644
--- a/embassy-stm32f4/src/exti.rs
+++ b/embassy-stm32f4/src/exti.rs
@@ -19,7 +19,7 @@ pub struct ExtiManager {
 
 impl<'a> ExtiManager {
     pub fn new(_exti: EXTI, syscfg: SysCfg) -> Self {
-        Self { syscfg: syscfg }
+        Self { syscfg }
     }
 
     pub fn new_pin<T, I>(&'static mut self, mut pin: T, interrupt: I) -> ExtiPin<T, I>
@@ -30,8 +30,8 @@ impl<'a> ExtiManager {
         pin.make_interrupt_source(&mut self.syscfg);
 
         ExtiPin {
-            pin: pin,
-            interrupt: interrupt,
+            pin,
+            interrupt,
             _mgr: self,
         }
     }
diff --git a/embassy-stm32f4/src/fmt.rs b/embassy-stm32f4/src/fmt.rs
index 4da69766c..1be1057a7 100644
--- a/embassy-stm32f4/src/fmt.rs
+++ b/embassy-stm32f4/src/fmt.rs
@@ -1,4 +1,5 @@
 #![macro_use]
+#![allow(clippy::module_inception)]
 
 #[cfg(all(feature = "defmt", feature = "log"))]
 compile_error!("You may not enable both `defmt` and `log` features.");
diff --git a/embassy-stm32f4/src/lib.rs b/embassy-stm32f4/src/lib.rs
index 57b9db965..02668b7eb 100644
--- a/embassy-stm32f4/src/lib.rs
+++ b/embassy-stm32f4/src/lib.rs
@@ -2,7 +2,6 @@
 #![feature(generic_associated_types)]
 #![feature(asm)]
 #![feature(type_alias_impl_trait)]
-#![feature(let_chains)]
 
 #[cfg(not(any(
     feature = "stm32f401",
diff --git a/embassy-stm32f4/src/serial.rs b/embassy-stm32f4/src/serial.rs
index f73c1b7c9..57fa14175 100644
--- a/embassy-stm32f4/src/serial.rs
+++ b/embassy-stm32f4/src/serial.rs
@@ -7,32 +7,21 @@
 use core::future::Future;
 use core::ptr;
 use core::sync::atomic::{self, Ordering};
-use core::task::{Context, Poll};
 
 use embassy::interrupt::OwnedInterrupt;
 use embassy::uart::{Error, Uart};
 use embassy::util::Signal;
-use embedded_dma::StaticWriteBuffer;
 
 use crate::hal::dma::config::DmaConfig;
 use crate::hal::dma::traits::{PeriAddress, Stream};
-use crate::hal::dma::{
-    Channel4, MemoryToPeripheral, PeripheralToMemory, Stream2, Stream7, StreamsTuple, Transfer,
-};
-use crate::hal::gpio::gpioa::{PA10, PA9};
-use crate::hal::gpio::{Alternate, AF7};
-use crate::hal::prelude::*;
+use crate::hal::dma::{Stream2, Stream7, StreamsTuple, Transfer};
 use crate::hal::rcc::Clocks;
-use crate::hal::serial::config::{
-    Config as SerialConfig, DmaConfig as SerialDmaConfig, Parity, StopBits, WordLength,
-};
+use crate::hal::serial::config::{Config as SerialConfig, DmaConfig as SerialDmaConfig};
 use crate::hal::serial::Pins;
 use crate::hal::serial::{Event as SerialEvent, Serial as HalSerial};
-use crate::hal::time::Bps;
 
 use crate::interrupt;
 
-use crate::pac::Interrupt;
 use crate::pac::{DMA2, USART1};
 
 /// Interface to the Serial peripheral
diff --git a/embassy/src/executor/mod.rs b/embassy/src/executor/mod.rs
index 3ba0cea60..65db28fcd 100644
--- a/embassy/src/executor/mod.rs
+++ b/embassy/src/executor/mod.rs
@@ -16,7 +16,7 @@ mod util;
 mod waker;
 
 use self::util::UninitCell;
-use crate::fmt::{panic, *};
+use crate::fmt::panic;
 use crate::interrupt::OwnedInterrupt;
 use crate::time::Alarm;
 
@@ -56,10 +56,10 @@ impl<F: Future + 'static> Task<F> {
             }
         }
 
-        return SpawnToken {
+        SpawnToken {
             raw_task: None,
             phantom: PhantomData,
-        };
+        }
     }
 
     unsafe fn poll(p: NonNull<raw::Task>) {
diff --git a/embassy/src/executor/timer_queue.rs b/embassy/src/executor/timer_queue.rs
index c722ae00b..38c237572 100644
--- a/embassy/src/executor/timer_queue.rs
+++ b/embassy/src/executor/timer_queue.rs
@@ -2,7 +2,7 @@ use core::cell::Cell;
 use core::cmp::min;
 use core::ptr;
 use core::ptr::NonNull;
-use core::sync::atomic::{AtomicPtr, Ordering};
+use core::sync::atomic::Ordering;
 
 use super::raw::{Task, STATE_TIMER_QUEUED};
 use crate::time::Instant;
diff --git a/embassy/src/fmt.rs b/embassy/src/fmt.rs
index 4da69766c..1be1057a7 100644
--- a/embassy/src/fmt.rs
+++ b/embassy/src/fmt.rs
@@ -1,4 +1,5 @@
 #![macro_use]
+#![allow(clippy::module_inception)]
 
 #[cfg(all(feature = "defmt", feature = "log"))]
 compile_error!("You may not enable both `defmt` and `log` features.");
diff --git a/embassy/src/interrupt.rs b/embassy/src/interrupt.rs
index 45676b31c..9ed0d3293 100644
--- a/embassy/src/interrupt.rs
+++ b/embassy/src/interrupt.rs
@@ -1,6 +1,5 @@
-use core::mem;
 use core::ptr;
-use core::sync::atomic::{AtomicBool, AtomicPtr, Ordering};
+use core::sync::atomic::{AtomicPtr, Ordering};
 use cortex_m::peripheral::NVIC;
 
 pub use embassy_macros::interrupt_declare as declare;
diff --git a/embassy/src/io/util/copy_buf.rs b/embassy/src/io/util/copy_buf.rs
index c037f3b02..c7e324d92 100644
--- a/embassy/src/io/util/copy_buf.rs
+++ b/embassy/src/io/util/copy_buf.rs
@@ -71,7 +71,7 @@ where
 
             let i = ready!(Pin::new(&mut this.writer).poll_write(cx, buffer))?;
             if i == 0 {
-                return Poll::Ready(Err(Error::WriteZero.into()));
+                return Poll::Ready(Err(Error::WriteZero));
             }
             *this.amt += i;
             this.reader.as_mut().consume(i);
diff --git a/embassy/src/io/util/drain.rs b/embassy/src/io/util/drain.rs
index d3f21d071..2542876d8 100644
--- a/embassy/src/io/util/drain.rs
+++ b/embassy/src/io/util/drain.rs
@@ -1,10 +1,8 @@
-use core::iter::Iterator;
 use core::pin::Pin;
 use futures::future::Future;
-use futures::ready;
 use futures::task::{Context, Poll};
 
-use super::super::error::{Error, Result};
+use super::super::error::Result;
 use super::super::traits::AsyncBufRead;
 
 pub struct Drain<'a, R: ?Sized> {
diff --git a/embassy/src/io/util/mod.rs b/embassy/src/io/util/mod.rs
index a9a00f809..de6643cb3 100644
--- a/embassy/src/io/util/mod.rs
+++ b/embassy/src/io/util/mod.rs
@@ -75,14 +75,14 @@ pub trait AsyncBufReadExt: AsyncBufRead {
         ReadWhile::new(self, f, buf)
     }
 
-    fn skip_while<'a, F: Fn(u8) -> bool>(&'a mut self, f: F) -> SkipWhile<'a, Self, F>
+    fn skip_while<F: Fn(u8) -> bool>(&mut self, f: F) -> SkipWhile<Self, F>
     where
         Self: Unpin,
     {
         SkipWhile::new(self, f)
     }
 
-    fn drain<'a>(&'a mut self) -> Drain<'a, Self>
+    fn drain(&mut self) -> Drain<Self>
     where
         Self: Unpin,
     {
@@ -96,14 +96,14 @@ pub trait AsyncBufReadExt: AsyncBufRead {
         Read::new(self, buf)
     }
 
-    fn read_buf<'a>(&'a mut self) -> ReadBuf<'a, Self>
+    fn read_buf(&mut self) -> ReadBuf<Self>
     where
         Self: Unpin,
     {
         ReadBuf::new(self)
     }
 
-    fn read_byte<'a>(&'a mut self) -> ReadByte<'a, Self>
+    fn read_byte(&mut self) -> ReadByte<Self>
     where
         Self: Unpin,
     {
@@ -147,12 +147,19 @@ pub trait AsyncWriteExt: AsyncWrite {
         WriteAll::new(self, buf)
     }
 
-    fn write_byte<'a>(&'a mut self, byte: u8) -> WriteByte<'a, Self>
+    fn write_byte(&mut self, byte: u8) -> WriteByte<Self>
     where
         Self: Unpin,
     {
         WriteByte::new(self, byte)
     }
+
+    fn write<'a>(&'a mut self, buf: &'a [u8]) -> Write<'a, Self>
+    where
+        Self: Unpin,
+    {
+        Write::new(self, buf)
+    }
 }
 
 impl<R: AsyncWrite + ?Sized> AsyncWriteExt for R {}
diff --git a/embassy/src/io/util/read_byte.rs b/embassy/src/io/util/read_byte.rs
index 7b7865ba9..e5bbcb1ff 100644
--- a/embassy/src/io/util/read_byte.rs
+++ b/embassy/src/io/util/read_byte.rs
@@ -25,7 +25,7 @@ impl<'a, R: AsyncBufRead + ?Sized + Unpin> Future for ReadByte<'a, R> {
         let Self { reader } = &mut *self;
         let mut reader = Pin::new(reader);
         let rbuf = ready!(reader.as_mut().poll_fill_buf(cx))?;
-        if rbuf.len() == 0 {
+        if rbuf.is_empty() {
             return Poll::Ready(Err(Error::UnexpectedEof));
         }
 
diff --git a/embassy/src/io/util/read_exact.rs b/embassy/src/io/util/read_exact.rs
index b7f7355ef..80c9376d5 100644
--- a/embassy/src/io/util/read_exact.rs
+++ b/embassy/src/io/util/read_exact.rs
@@ -31,7 +31,7 @@ impl<R: AsyncBufRead + ?Sized + Unpin> Future for ReadExact<'_, R> {
         let this = &mut *self;
         while !this.buf.is_empty() {
             let buf = ready!(Pin::new(&mut this.reader).poll_fill_buf(cx))?;
-            if buf.len() == 0 {
+            if buf.is_empty() {
                 return Poll::Ready(Err(Error::UnexpectedEof));
             }
 
diff --git a/embassy/src/io/util/read_to_end.rs b/embassy/src/io/util/read_to_end.rs
index 2da6c74d8..d09999ad0 100644
--- a/embassy/src/io/util/read_to_end.rs
+++ b/embassy/src/io/util/read_to_end.rs
@@ -29,7 +29,7 @@ impl<'a, R: AsyncBufRead + ?Sized + Unpin> Future for ReadToEnd<'a, R> {
         let mut reader = Pin::new(reader);
         loop {
             let rbuf = ready!(reader.as_mut().poll_fill_buf(cx))?;
-            if rbuf.len() == 0 {
+            if rbuf.is_empty() {
                 return Poll::Ready(Ok(*n));
             }
 
diff --git a/embassy/src/io/util/read_while.rs b/embassy/src/io/util/read_while.rs
index ab46cee38..e24638039 100644
--- a/embassy/src/io/util/read_while.rs
+++ b/embassy/src/io/util/read_while.rs
@@ -35,7 +35,7 @@ impl<'a, R: AsyncBufRead + ?Sized + Unpin, F: Fn(u8) -> bool> Future for ReadWhi
         let mut reader = Pin::new(reader);
         loop {
             let rbuf = ready!(reader.as_mut().poll_fill_buf(cx))?;
-            if rbuf.len() == 0 {
+            if rbuf.is_empty() {
                 return Poll::Ready(Err(Error::UnexpectedEof));
             }
 
diff --git a/embassy/src/io/util/skip_while.rs b/embassy/src/io/util/skip_while.rs
index 8c81ad209..6f0e167df 100644
--- a/embassy/src/io/util/skip_while.rs
+++ b/embassy/src/io/util/skip_while.rs
@@ -28,7 +28,7 @@ impl<'a, R: AsyncBufRead + ?Sized + Unpin, F: Fn(u8) -> bool> Future for SkipWhi
         let mut reader = Pin::new(reader);
         loop {
             let buf = ready!(reader.as_mut().poll_fill_buf(cx))?;
-            if buf.len() == 0 {
+            if buf.is_empty() {
                 return Poll::Ready(Err(Error::UnexpectedEof));
             }
 
diff --git a/embassy/src/time/instant.rs b/embassy/src/time/instant.rs
index e1aff11c4..06ab84c75 100644
--- a/embassy/src/time/instant.rs
+++ b/embassy/src/time/instant.rs
@@ -1,4 +1,3 @@
-use core::convert::TryInto;
 use core::fmt;
 use core::ops::{Add, AddAssign, Sub, SubAssign};
 
@@ -49,7 +48,7 @@ impl Instant {
 
     pub fn duration_since(&self, earlier: Instant) -> Duration {
         Duration {
-            ticks: (self.ticks - earlier.ticks).try_into().unwrap(),
+            ticks: self.ticks.checked_sub(earlier.ticks).unwrap(),
         }
     }
 
@@ -58,7 +57,7 @@ impl Instant {
             None
         } else {
             Some(Duration {
-                ticks: (self.ticks - earlier.ticks).try_into().unwrap(),
+                ticks: self.ticks - earlier.ticks,
             })
         }
     }
@@ -68,7 +67,7 @@ impl Instant {
             ticks: if self.ticks < earlier.ticks {
                 0
             } else {
-                (self.ticks - earlier.ticks).try_into().unwrap()
+                self.ticks - earlier.ticks
             },
         }
     }
@@ -79,12 +78,12 @@ impl Instant {
 
     pub fn checked_add(&self, duration: Duration) -> Option<Instant> {
         self.ticks
-            .checked_add(duration.ticks.into())
+            .checked_add(duration.ticks)
             .map(|ticks| Instant { ticks })
     }
     pub fn checked_sub(&self, duration: Duration) -> Option<Instant> {
         self.ticks
-            .checked_sub(duration.ticks.into())
+            .checked_sub(duration.ticks)
             .map(|ticks| Instant { ticks })
     }
 }
diff --git a/embassy/src/util/mutex.rs b/embassy/src/util/mutex.rs
index f87d70034..ed2fd7852 100644
--- a/embassy/src/util/mutex.rs
+++ b/embassy/src/util/mutex.rs
@@ -1,7 +1,7 @@
 use core::cell::UnsafeCell;
 use cortex_m::interrupt::CriticalSection;
 
-use crate::fmt::{assert, panic, *};
+use crate::fmt::assert;
 
 /// A "mutex" based on critical sections
 ///
diff --git a/embassy/src/util/portal.rs b/embassy/src/util/portal.rs
index 05bdccf58..f4f2824aa 100644
--- a/embassy/src/util/portal.rs
+++ b/embassy/src/util/portal.rs
@@ -1,6 +1,5 @@
 use crate::fmt::panic;
 use core::cell::UnsafeCell;
-use core::future::Future;
 use core::mem;
 use core::mem::MaybeUninit;
 
@@ -34,93 +33,89 @@ impl<T> Portal<T> {
         }
     }
 
-    pub fn wait_once<'a, R, F>(&'a self, mut func: F) -> impl Future<Output = R> + 'a
+    pub async fn wait_once<'a, R, F>(&'a self, mut func: F) -> R
     where
         F: FnMut(T) -> R + 'a,
     {
-        async move {
-            let bomb = DropBomb::new();
-
-            let signal = Signal::new();
-            let mut result: MaybeUninit<R> = MaybeUninit::uninit();
-            let mut call_func = |val: T| {
-                unsafe {
-                    let state = &mut *self.state.get();
-                    *state = State::None;
-                    result.as_mut_ptr().write(func(val))
-                };
-                signal.signal(());
-            };
-
-            let func_ptr: *mut dyn FnMut(T) = &mut call_func as _;
-            let func_ptr: *mut dyn FnMut(T) = unsafe { mem::transmute(func_ptr) };
+        let bomb = DropBomb::new();
 
+        let signal = Signal::new();
+        let mut result: MaybeUninit<R> = MaybeUninit::uninit();
+        let mut call_func = |val: T| {
             unsafe {
                 let state = &mut *self.state.get();
-                match state {
-                    State::None => {}
-                    _ => panic!("Multiple tasks waiting on same portal"),
-                }
-                *state = State::Waiting(func_ptr);
+                *state = State::None;
+                result.as_mut_ptr().write(func(val))
+            };
+            signal.signal(());
+        };
+
+        let func_ptr: *mut dyn FnMut(T) = &mut call_func as _;
+        let func_ptr: *mut dyn FnMut(T) = unsafe { mem::transmute(func_ptr) };
+
+        unsafe {
+            let state = &mut *self.state.get();
+            match state {
+                State::None => {}
+                _ => panic!("Multiple tasks waiting on same portal"),
             }
+            *state = State::Waiting(func_ptr);
+        }
 
-            signal.wait().await;
+        signal.wait().await;
 
-            bomb.defuse();
+        bomb.defuse();
 
-            unsafe { result.assume_init() }
-        }
+        unsafe { result.assume_init() }
     }
 
-    pub fn wait_many<'a, R, F>(&'a self, mut func: F) -> impl Future<Output = R> + 'a
+    pub async fn wait_many<'a, R, F>(&'a self, mut func: F) -> R
     where
         F: FnMut(T) -> Option<R> + 'a,
     {
-        async move {
-            let bomb = DropBomb::new();
-
-            let signal = Signal::new();
-            let mut result: MaybeUninit<R> = MaybeUninit::uninit();
-            let mut call_func = |val: T| {
-                unsafe {
-                    let state = &mut *self.state.get();
-
-                    let func_ptr = match *state {
-                        State::Waiting(p) => p,
-                        _ => unreachable!(),
-                    };
-
-                    // Set state to Running while running the function to avoid reentrancy.
-                    *state = State::Running;
-
-                    *state = match func(val) {
-                        None => State::Waiting(func_ptr),
-                        Some(res) => {
-                            result.as_mut_ptr().write(res);
-                            signal.signal(());
-                            State::None
-                        }
-                    };
+        let bomb = DropBomb::new();
+
+        let signal = Signal::new();
+        let mut result: MaybeUninit<R> = MaybeUninit::uninit();
+        let mut call_func = |val: T| {
+            unsafe {
+                let state = &mut *self.state.get();
+
+                let func_ptr = match *state {
+                    State::Waiting(p) => p,
+                    _ => unreachable!(),
+                };
+
+                // Set state to Running while running the function to avoid reentrancy.
+                *state = State::Running;
+
+                *state = match func(val) {
+                    None => State::Waiting(func_ptr),
+                    Some(res) => {
+                        result.as_mut_ptr().write(res);
+                        signal.signal(());
+                        State::None
+                    }
                 };
             };
+        };
 
-            let func_ptr: *mut dyn FnMut(T) = &mut call_func as _;
-            let func_ptr: *mut dyn FnMut(T) = unsafe { mem::transmute(func_ptr) };
+        let func_ptr: *mut dyn FnMut(T) = &mut call_func as _;
+        let func_ptr: *mut dyn FnMut(T) = unsafe { mem::transmute(func_ptr) };
 
-            unsafe {
-                let state = &mut *self.state.get();
-                match *state {
-                    State::None => {}
-                    _ => panic!("Multiple tasks waiting on same portal"),
-                }
-                *state = State::Waiting(func_ptr);
+        unsafe {
+            let state = &mut *self.state.get();
+            match *state {
+                State::None => {}
+                _ => panic!("Multiple tasks waiting on same portal"),
             }
+            *state = State::Waiting(func_ptr);
+        }
 
-            signal.wait().await;
+        signal.wait().await;
 
-            bomb.defuse();
+        bomb.defuse();
 
-            unsafe { result.assume_init() }
-        }
+        unsafe { result.assume_init() }
     }
 }
diff --git a/embassy/src/util/signal.rs b/embassy/src/util/signal.rs
index c8b7a61a6..89cc03f2c 100644
--- a/embassy/src/util/signal.rs
+++ b/embassy/src/util/signal.rs
@@ -32,9 +32,8 @@ impl<T: Send> Signal<T> {
     pub fn signal(&self, val: T) {
         cortex_m::interrupt::free(|_| unsafe {
             let state = &mut *self.state.get();
-            match mem::replace(state, State::Signaled(val)) {
-                State::Waiting(waker) => waker.wake(),
-                _ => {}
+            if let State::Waiting(waker) = mem::replace(state, State::Signaled(val)) {
+                waker.wake();
             }
         })
     }
@@ -98,9 +97,7 @@ impl<'a, I: OwnedInterrupt> InterruptFuture<'a, I> {
         interrupt.unpend();
         interrupt.enable();
 
-        Self {
-            interrupt: interrupt,
-        }
+        Self { interrupt }
     }
 
     unsafe fn interrupt_handler(ctx: *mut ()) {
@@ -109,7 +106,7 @@ impl<'a, I: OwnedInterrupt> InterruptFuture<'a, I> {
             _ => unreachable!(),
         };
 
-        if ctx as *const _ != ptr::null() {
+        if !ctx.is_null() {
             executor::raw::wake_task(ptr::NonNull::new_unchecked(ctx as _));
         }
 
diff --git a/embassy/src/util/waker.rs b/embassy/src/util/waker.rs
index 83fd8b4ff..68e45cf1a 100644
--- a/embassy/src/util/waker.rs
+++ b/embassy/src/util/waker.rs
@@ -40,7 +40,9 @@ impl WakerRegistration {
 
     /// Wake the registered waker, if any.
     pub fn wake(&mut self) {
-        self.waker.take().map(|w| w.wake());
+        if let Some(w) = self.waker.take() {
+            w.wake()
+        }
     }
 
     pub fn context(&self) -> Option<Context<'_>> {