Applied a healthy dose of warning cleanup

Signed-off-by: Daniel Egger <daniel@eggers-club.de>
3 years ago · 97128234d7
19 changed files with 249 additions and 53 deletions
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@ -19,6 +19,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).

 - Removed superfluous use statements
 - Re-added Send ability for U(S)ART Rx/Tx
+- Made crate to compile without features
+- Eliminated a lot of unused warnings

 ### Fixed

--- a/README.md
+++ b/README.md
@ -6,12 +6,12 @@ API for the STMicro STM32F0xx family of microcontrollers. It replaces the
 [stm32f042-hal][] by a more ubiqitous version suitable for additional families.

 Currently supported configuration are:
-* stm32f042
 * stm32f030
 * stm32f030x4
 * stm32f030x6
 * stm32f030x8
 * stm32f030xc
+* stm32f042
 * stm32f070
 * stm32f070x6
 * stm32f070xb
--- a/examples/blinky.rs
+++ b/examples/blinky.rs
@ -1,6 +1,7 @@
 #![no_main]
 #![no_std]

+#[allow(unused)]
 use panic_halt;

 use stm32f0xx_hal as hal;
--- a/examples/blinky_delay.rs
+++ b/examples/blinky_delay.rs
@ -1,6 +1,7 @@
 #![no_main]
 #![no_std]

+#[allow(unused)]
 use panic_halt;

 use stm32f0xx_hal as hal;
--- a/examples/blinky_multiple.rs
+++ b/examples/blinky_multiple.rs
@ -1,6 +1,7 @@
 #![no_main]
 #![no_std]

+#[allow(unused)]
 use panic_halt;

 use stm32f0xx_hal as hal;
--- a/examples/blinky_timer.rs
+++ b/examples/blinky_timer.rs
@ -1,6 +1,7 @@
 #![no_main]
 #![no_std]

+#[allow(unused)]
 use panic_halt;

 use stm32f0xx_hal as hal;
--- a/examples/flash_systick.rs
+++ b/examples/flash_systick.rs
@ -1,6 +1,7 @@
 #![no_main]
 #![no_std]

+#[allow(unused)]
 use panic_halt;

 use stm32f0xx_hal as hal;
--- a/examples/led_hal_button_irq.rs
+++ b/examples/led_hal_button_irq.rs
@ -1,6 +1,7 @@
 #![no_main]
 #![no_std]

+#[allow(unused)]
 use panic_halt;

 use stm32f0xx_hal as hal;
@ -84,7 +85,6 @@ fn main() -> ! {
    }
 }

-
 // Define an interupt handler, i.e. function to call when interrupt occurs. Here if our external
 // interrupt trips when the button is pressed and will light the LED for a second
 #[interrupt]
--- a/examples/serial_echo.rs
+++ b/examples/serial_echo.rs
@ -1,6 +1,7 @@
 #![no_main]
 #![no_std]

+#[allow(unused)]
 use panic_halt;

 use stm32f0xx_hal as hal;
--- a/examples/spi_hal_apa102c.rs
+++ b/examples/spi_hal_apa102c.rs
@ -1,6 +1,7 @@
 #![no_main]
 #![no_std]

+#[allow(unused)]
 use panic_halt;

 use stm32f0xx_hal as hal;
--- a/examples/watchdog.rs
+++ b/examples/watchdog.rs
@ -1,6 +1,7 @@
 #![no_main]
 #![no_std]

+#[allow(unused)]
 use panic_halt;

 use core::fmt::Write;
--- a/src/gpio.rs
+++ b/src/gpio.rs
@ -107,6 +107,7 @@ impl<MODE> InputPin for Pin<Input<MODE>> {
    }
 }

+#[allow(unused)]
 macro_rules! gpio_trait {
    ($gpiox:ident) => {
        impl GpioRegExt for crate::stm32::$gpiox::RegisterBlock {
@ -133,9 +134,21 @@ macro_rules! gpio_trait {
    };
 }

+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 gpio_trait!(gpioa);
+
+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 gpio_trait!(gpiof);

+#[allow(unused)]
 macro_rules! gpio {
    ($GPIOX:ident, $gpiox:ident, $iopxenr:ident, $PXx:ident, [
        $($PXi:ident: ($pxi:ident, $i:expr, $MODE:ty),)+
@ -497,7 +510,11 @@ macro_rules! gpio {
    }
 }

-#[cfg(any(feature = "stm32f042", feature = "stm32f030", feature = "stm32f070"))]
+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 gpio!(GPIOA, gpioa, iopaen, PA, [
    PA0: (pa0, 0, Input<Floating>),
    PA1: (pa1, 1, Input<Floating>),
@ -517,7 +534,11 @@ gpio!(GPIOA, gpioa, iopaen, PA, [
    PA15: (pa15, 15, Input<Floating>),
 ]);

-#[cfg(any(feature = "stm32f042", feature = "stm32f030", feature = "stm32f070"))]
+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 gpio!(GPIOB, gpiob, iopben, PB, [
    PB0: (pb0, 0, Input<Floating>),
    PB1: (pb1, 1, Input<Floating>),
--- a/src/i2c.rs
+++ b/src/i2c.rs
@ -1,13 +1,18 @@
+#[allow(unused)]
 use core::ops::Deref;

-use crate::stm32;
+#[allow(unused)]
 use embedded_hal::blocking::i2c::{Write, WriteRead};

-use crate::gpio::*;
-use crate::time::{KiloHertz, U32Ext};
-use core::cmp;
+#[allow(unused)]
+use crate::{
+    gpio::*,
+    stm32,
+    time::{KiloHertz, U32Ext},
+};

 /// I2C abstraction
+#[allow(unused)]
 pub struct I2c<I2C, SCLPIN, SDAPIN> {
    i2c: I2C,
    pins: (SCLPIN, SDAPIN),
@ -16,6 +21,7 @@ pub struct I2c<I2C, SCLPIN, SDAPIN> {
 pub trait SclPin<I2C> {}
 pub trait SdaPin<I2C> {}

+#[allow(unused)]
 macro_rules! i2c_pins {
    ($($I2C:ident => {
        scl => [$($scl:ty),+ $(,)*],
@ -32,7 +38,7 @@ macro_rules! i2c_pins {
    }
 }

-#[cfg(any(feature = "stm32f042", feature = "stm32f030"))]
+#[cfg(any(feature = "stm32f030", feature = "stm32f042"))]
 i2c_pins! {
    I2C1 => {
        scl => [gpioa::PA11<Alternate<AF5>>, gpiob::PB6<Alternate<AF1>>, gpiob::PB8<Alternate<AF1>>],
@ -40,9 +46,9 @@ i2c_pins! {
    }
 }
 #[cfg(any(
-    feature = "stm32f042",
    feature = "stm32f030x6",
-    feature = "stm32f030xc"
+    feature = "stm32f030xc",
+    feature = "stm32f042",
 ))]
 i2c_pins! {
    I2C1 => {
@ -103,6 +109,7 @@ pub enum Error {
    NACK,
 }

+#[allow(unused)]
 macro_rules! i2c {
    ($($I2C:ident: ($i2c:ident, $i2cXen:ident, $i2cXrst:ident, $apbenr:ident, $apbrstr:ident),)+) => {
        $(
@ -128,12 +135,17 @@ macro_rules! i2c {
        )+
    }
 }
-#[cfg(any(feature = "stm32f042", feature = "stm32f030", feature = "stm32f070"))]
+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 i2c! {
    I2C1: (i2c1, i2c1en, i2c1rst, apb1enr, apb1rstr),
 }
 #[cfg(any(
    feature = "stm32f030xc",
+    // XXX: This can't be right
    feature = "stm32f030xc",
    feature = "stm32f070xb"
 ))]
@ -142,13 +154,26 @@ i2c! {
 }

 // It's s needed for the impls, but rustc doesn't recognize that
+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 #[allow(dead_code)]
 type I2cRegisterBlock = stm32::i2c1::RegisterBlock;
+
+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 impl<I2C, SCLPIN, SDAPIN> I2c<I2C, SCLPIN, SDAPIN>
 where
    I2C: Deref<Target = I2cRegisterBlock>,
 {
    fn i2c_init(self: Self, speed: KiloHertz) -> Self {
+        use core::cmp;
+
        /* Make sure the I2C unit is disabled so we can configure it */
        self.i2c.cr1.modify(|_, w| w.pe().clear_bit());

@ -226,6 +251,11 @@ where
    }
 }

+#[cfg(any(
+    feature = "stm32f042",
+    feature = "stm32f030",
+    feature = "stm32f070"
+))]
 impl<I2C, SCLPIN, SDAPIN> WriteRead for I2c<I2C, SCLPIN, SDAPIN>
 where
    I2C: Deref<Target = I2cRegisterBlock>,
@ -306,6 +336,11 @@ where
    }
 }

+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 impl<I2C, SCLPIN, SDAPIN> Write for I2c<I2C, SCLPIN, SDAPIN>
 where
    I2C: Deref<Target = I2cRegisterBlock>,
--- a/src/lib.rs
+++ b/src/lib.rs
@ -9,6 +9,13 @@ pub use stm32f0::stm32f0x2 as stm32;
 #[cfg(any(feature = "stm32f030", feature = "stm32f070"))]
 pub use stm32f0::stm32f0x0 as stm32;

+#[cfg(not(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+)))]
+pub mod stm32 {}
+
 pub mod delay;
 pub mod gpio;
 pub mod i2c;
--- a/src/rcc.rs
+++ b/src/rcc.rs
@ -1,8 +1,9 @@
-use core::cmp;
-
-#[cfg(any(feature = "stm32f042", feature = "stm32f030", feature = "stm32f070"))]
+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 use crate::stm32::{FLASH, RCC};
-use cast::u32;

 use crate::time::Hertz;

@ -12,7 +13,11 @@ pub trait RccExt {
    fn constrain(self) -> Rcc;
 }

-#[cfg(any(feature = "stm32f042", feature = "stm32f030", feature = "stm32f070"))]
+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 impl RccExt for RCC {
    fn constrain(self) -> Rcc {
        Rcc {
@ -30,15 +35,21 @@ pub struct Rcc {
    pub cfgr: CFGR,
 }

+#[allow(unused)]
 const HSI: u32 = 8_000_000; // Hz

+#[allow(unused)]
 pub struct CFGR {
    hclk: Option<u32>,
    pclk: Option<u32>,
    sysclk: Option<u32>,
 }

-#[cfg(any(feature = "stm32f042", feature = "stm32f030", feature = "stm32f070"))]
+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 impl CFGR {
    pub fn hclk<F>(mut self, freq: F) -> Self
    where
@ -66,7 +77,7 @@ impl CFGR {

    pub fn freeze(self) -> Clocks {
        let pllmul = (4 * self.sysclk.unwrap_or(HSI) + HSI) / HSI / 2;
-        let pllmul = cmp::min(cmp::max(pllmul, 2), 16);
+        let pllmul = core::cmp::min(core::cmp::max(pllmul, 2), 16);
        let sysclk = pllmul * HSI / 2;

        let pllmul_bits = if pllmul == 2 {
@ -106,7 +117,7 @@ impl CFGR {
            .unwrap_or(0b011);

        let ppre: u8 = 1 << (ppre_bits - 0b011);
-        let pclk = hclk / u32(ppre);
+        let pclk = hclk / cast::u32(ppre);

        // adjust flash wait states
        unsafe {
--- a/src/serial.rs
+++ b/src/serial.rs
@ -23,20 +23,18 @@
 //! }
 //! ```

-use core::fmt::{Result, Write};
-use core::ops::Deref;
-use core::ptr;
-
+#[allow(unused)]
+use core::{
+    fmt::{Result, Write},
+    ops::Deref,
+    ptr,
+};
+
+#[allow(unused)]
 use embedded_hal::prelude::*;
-use nb::block;
-use void::Void;
-
-#[cfg(any(feature = "stm32f042", feature = "stm32f030", feature = "stm32f070"))]
-use crate::stm32;

-use crate::gpio::*;
-use crate::rcc::Clocks;
-use crate::time::Bps;
+#[allow(unused)]
+use crate::{gpio::*, rcc::Clocks, stm32, time::Bps};

 /// Interrupt event
 pub enum Event {
@ -64,6 +62,7 @@ pub enum Error {
 pub trait TxPin<USART> {}
 pub trait RxPin<USART> {}

+#[allow(unused)]
 macro_rules! usart_pins {
    ($($USART:ident => {
        tx => [$($tx:ty),+ $(,)*],
@ -102,9 +101,9 @@ usart_pins! {
    }
 }
 #[cfg(any(
-    feature = "stm32f042",
    feature = "stm32f030x8",
    feature = "stm32f030xc",
+    feature = "stm32f042",
    feature = "stm32f070",
 ))]
 usart_pins! {
@ -138,12 +137,14 @@ usart_pins! {
 }

 /// Serial abstraction
+#[allow(unused)]
 pub struct Serial<USART, TXPIN, RXPIN> {
    usart: USART,
    pins: (TXPIN, RXPIN),
 }

 /// Serial receiver
+#[allow(unused)]
 pub struct Rx<USART> {
    // This is ok, because the USART types only contains PhantomData
    usart: *const USART,
@ -153,6 +154,7 @@ pub struct Rx<USART> {
 unsafe impl<USART> Send for Rx<USART> {}

 /// Serial transmitter
+#[allow(unused)]
 pub struct Tx<USART> {
    // This is ok, because the USART types only contains PhantomData
    usart: *const USART,
@ -161,6 +163,7 @@ pub struct Tx<USART> {
 // NOTE(unsafe) Required to allow protected shared access in handlers
 unsafe impl<USART> Send for Tx<USART> {}

+#[allow(unused)]
 macro_rules! usart {
    ($($USART:ident: ($usart:ident, $usartXen:ident, $apbenr:ident),)+) => {
        $(
@ -196,14 +199,18 @@ macro_rules! usart {
    }
 }

-#[cfg(any(feature = "stm32f042", feature = "stm32f030", feature = "stm32f070"))]
+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 usart! {
    USART1: (usart1, usart1en, apb2enr),
 }
 #[cfg(any(
-    feature = "stm32f042",
    feature = "stm32f030x8",
    feature = "stm32f030xc",
+    feature = "stm32f042",
    feature = "stm32f070",
 ))]
 usart! {
@ -222,8 +229,18 @@ usart! {

 // It's s needed for the impls, but rustc doesn't recognize that
 #[allow(dead_code)]
+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 type SerialRegisterBlock = stm32::usart1::RegisterBlock;

+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 impl<USART> embedded_hal::serial::Read<u8> for Rx<USART>
 where
    USART: Deref<Target = SerialRegisterBlock>,
@ -252,11 +269,16 @@ where
    }
 }

+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 impl<USART> embedded_hal::serial::Write<u8> for Tx<USART>
 where
    USART: Deref<Target = SerialRegisterBlock>,
 {
-    type Error = Void;
+    type Error = void::Void;

    /// Ensures that none of the previously written words are still buffered
    fn flush(&mut self) -> nb::Result<(), Self::Error> {
@ -287,6 +309,11 @@ where
    }
 }

+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 impl<USART, TXPIN, RXPIN> Serial<USART, TXPIN, RXPIN>
 where
    USART: Deref<Target = SerialRegisterBlock>,
@ -308,11 +335,18 @@ where
    }
 }

+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 impl<USART> Write for Tx<USART>
 where
    Tx<USART>: embedded_hal::serial::Write<u8>,
 {
    fn write_str(&mut self, s: &str) -> Result {
+        use nb::block;
+
        let _ = s.as_bytes().iter().map(|c| block!(self.write(*c))).last();
        Ok(())
    }
--- a/src/spi.rs
+++ b/src/spi.rs
@ -1,24 +1,37 @@
-use core::ops::Deref;
-use core::ptr;
+#[allow(unused)]
+use core::{ops::Deref, ptr};

+#[allow(unused)]
 use nb;

 pub use embedded_hal::spi::{Mode, Phase, Polarity};

+#[allow(unused)]
 use crate::stm32;
+
 // TODO Put this inside the macro
 // Currently that causes a compiler panic
-#[cfg(any(feature = "stm32f042", feature = "stm32f030", feature = "stm32f070"))]
+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 use crate::stm32::SPI1;
 #[cfg(any(
    feature = "stm32f030x8",
    feature = "stm32f030xc",
    feature = "stm32f070xb"
 ))]
+#[allow(unused)]
 use crate::stm32::SPI2;

+#[allow(unused)]
 use crate::gpio::*;
+
+#[allow(unused)]
 use crate::rcc::Clocks;
+
+#[allow(unused)]
 use crate::time::Hertz;

 /// SPI error
@ -35,6 +48,7 @@ pub enum Error {
 }

 /// SPI abstraction
+#[allow(unused)]
 pub struct Spi<SPI, SCKPIN, MISOPIN, MOSIPIN> {
    spi: SPI,
    pins: (SCKPIN, MISOPIN, MOSIPIN),
@ -44,6 +58,7 @@ pub trait SckPin<SPI> {}
 pub trait MisoPin<SPI> {}
 pub trait MosiPin<SPI> {}

+#[allow(unused)]
 macro_rules! spi_pins {
    ($($SPI:ident => {
        sck => [$($sck:ty),+ $(,)*],
@ -64,7 +79,11 @@ macro_rules! spi_pins {
    }
 }

-#[cfg(any(feature = "stm32f042", feature = "stm32f030", feature = "stm32f070"))]
+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 spi_pins! {
    SPI1 => {
        sck => [gpioa::PA5<Alternate<AF0>>, gpiob::PB3<Alternate<AF0>>],
@ -101,6 +120,7 @@ spi_pins! {
    }
 }

+#[allow(unused)]
 macro_rules! spi {
    ($($SPI:ident: ($spi:ident, $spiXen:ident, $spiXrst:ident, $apbenr:ident, $apbrstr:ident),)+) => {
        $(
@ -134,7 +154,11 @@ macro_rules! spi {
    }
 }

-#[cfg(any(feature = "stm32f042", feature = "stm32f030", feature = "stm32f070"))]
+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 spi! {
    SPI1: (spi1, spi1en, spi1rst, apb2enr, apb2rstr),
 }
@ -149,8 +173,18 @@ spi! {

 // It's s needed for the impls, but rustc doesn't recognize that
 #[allow(dead_code)]
+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 type SpiRegisterBlock = stm32::spi1::RegisterBlock;

+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 impl<SPI, SCKPIN, MISOPIN, MOSIPIN> Spi<SPI, SCKPIN, MISOPIN, MOSIPIN>
 where
    SPI: Deref<Target = SpiRegisterBlock>,
@ -221,6 +255,11 @@ where
    }
 }

+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 impl<SPI, SCKPIN, MISOPIN, MOSIPIN> ::embedded_hal::spi::FullDuplex<u8>
    for Spi<SPI, SCKPIN, MISOPIN, MOSIPIN>
 where
@ -265,15 +304,24 @@ where
    }
 }

+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 impl<SPI, SCKPIN, MISOPIN, MOSIPIN> ::embedded_hal::blocking::spi::transfer::Default<u8>
    for Spi<SPI, SCKPIN, MISOPIN, MOSIPIN>
 where
    SPI: Deref<Target = SpiRegisterBlock>,
-{
-}
+{}
+
+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 impl<SPI, SCKPIN, MISOPIN, MOSIPIN> ::embedded_hal::blocking::spi::write::Default<u8>
    for Spi<SPI, SCKPIN, MISOPIN, MOSIPIN>
 where
    SPI: Deref<Target = SpiRegisterBlock>,
-{
-}
+{}
--- a/src/timers.rs
+++ b/src/timers.rs
@ -24,12 +24,10 @@
 //! }
 //! ```

-use crate::stm32;
 use cortex_m::peripheral::syst::SystClkSource;
 use cortex_m::peripheral::SYST;

 use crate::rcc::Clocks;
-use cast::{u16, u32};
 use embedded_hal::timer::{CountDown, Periodic};
 use nb;
 use void::Void;
@ -105,6 +103,7 @@ impl CountDown for Timer<SYST> {

 impl Periodic for Timer<SYST> {}

+#[allow(unused)]
 macro_rules! timers {
    ($($TIM:ident: ($tim:ident, $timXen:ident, $timXrst:ident, $apbenr:ident, $apbrstr:ident),)+) => {
        $(
@ -119,7 +118,7 @@ macro_rules! timers {
                    T: Into<Hertz>,
                {
                    // NOTE(unsafe) This executes only during initialisation
-                    let rcc = unsafe { &(*stm32::RCC::ptr()) };
+                    let rcc = unsafe { &(*crate::stm32::RCC::ptr()) };

                    // enable and reset peripheral to a clean slate state
                    rcc.$apbenr.modify(|_, w| w.$timXen().set_bit());
@ -157,7 +156,7 @@ macro_rules! timers {

                /// Releases the TIM peripheral
                pub fn release(self) -> $TIM {
-                    let rcc = unsafe { &(*stm32::RCC::ptr()) };
+                    let rcc = unsafe { &(*crate::stm32::RCC::ptr()) };
                    // Pause counter
                    self.tim.cr1.modify(|_, w| w.cen().clear_bit());
                    // Disable timer
@ -182,11 +181,11 @@ macro_rules! timers {
                    let frequency = timeout.into().0;
                    let ticks = self.clocks.pclk().0 / frequency;

-                    let psc = u16((ticks - 1) / (1 << 16)).unwrap();
+                    let psc = cast::u16((ticks - 1) / (1 << 16)).unwrap();
                    self.tim.psc.write(|w| unsafe { w.psc().bits(psc) });

-                    let arr = u16(ticks / u32(psc + 1)).unwrap();
-                    self.tim.arr.write(|w| unsafe { w.bits(u32(arr)) });
+                    let arr = cast::u16(ticks / cast::u32(psc + 1)).unwrap();
+                    self.tim.arr.write(|w| unsafe { w.bits(cast::u32(arr)) });

                    // start counter
                    self.tim.cr1.modify(|_, w| w.cen().set_bit());
@ -209,7 +208,11 @@ macro_rules! timers {
    }
 }

-#[cfg(any(feature = "stm32f030", feature = "stm32f042", feature = "stm32f070"))]
+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 timers! {
    TIM1: (tim1, tim1en, tim1rst, apb2enr, apb2rstr),
    TIM3: (tim3, tim3en, tim3rst, apb1enr, apb1rstr),
--- a/src/watchdog.rs
+++ b/src/watchdog.rs
@ -41,16 +41,32 @@
 //! // Whoops, got stuck, the watchdog issues a reset after 10 ms
 //! iwdg.feed();
 //! ```
+#[allow(unused)]
 use embedded_hal::watchdog;

+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 use crate::stm32::IWDG;
 use crate::time::Hertz;

+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 /// Watchdog instance
 pub struct Watchdog {
    iwdg: IWDG,
 }

+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 impl watchdog::Watchdog for Watchdog {
    /// Feed the watchdog, so that at least one `period` goes by before the next
    /// reset
@ -88,12 +104,23 @@ impl Into<IwdgTimeout> for Hertz {
        IwdgTimeout { psc, reload }
    }
 }
+
+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 impl Watchdog {
    pub fn new(iwdg: IWDG) -> Self {
        Self { iwdg }
    }
 }

+#[cfg(any(
+    feature = "stm32f030",
+    feature = "stm32f042",
+    feature = "stm32f070"
+))]
 impl watchdog::WatchdogEnable for Watchdog {
    type Time = IwdgTimeout;
    fn start<T>(&mut self, period: T)