const associated ICE

src/gpio.rs

@@ -57,7 +57,7 @@
 use core::marker::PhantomData;
 
 mod alt;
-pub(crate) use alt::{Const, PinA, SetAlternate};
+pub(crate) use alt::{PinA, SetAlternate};
 mod convert;
 pub use convert::PinMode;
 mod partially_erased;

src/gpio/alt.rs

@@ -1,8 +1,6 @@
 use super::{marker, Alternate, NoPin, OpenDrain, Pin, PinMode, PushPull};
 use crate::{gpio, i2c, i2s, pac, serial, spi};
 
-pub struct Const<const A: u8>;
-
 pub trait SetAlternate<const A: u8, Otype> {
     fn set_alt_mode(&mut self);
     fn restore_mode(&mut self);
@@ -50,23 +48,23 @@ impl<const P: char, const N: u8, const A: u8> SetAlternate<A, OpenDrain>
 }
 
 pub trait PinA<PIN, PER> {
-    type A;
+    const A: u8;
 }
 
 impl<PIN, PER> PinA<PIN, PER> for NoPin
 where
     PIN: crate::Sealed,
     PER: crate::Sealed,
 {
-    type A = Const<0>;
+    const A: u8 = 0;
 }
 
 macro_rules! pin {
     ( $(<$Pin:ty, $I2C:ident> for [$($PX:ident<$A:literal>),*]),*) => {
         $(
             $(
                 impl<MODE> PinA<$Pin, pac::$I2C> for gpio::$PX<MODE> {
-                    type A = Const<$A>;
+                    const A: u8 = $A;
                 }
             )*
         )*

src/i2c.rs

@@ -3,7 +3,7 @@ use core::ops::Deref;
 use crate::pac::{self, i2c1};
 use crate::rcc::{Enable, Reset};
 
-use crate::gpio::{Const, OpenDrain, PinA, SetAlternate};
+use crate::gpio::{OpenDrain, PinA, SetAlternate};
 use crate::pac::RCC;
 
 use crate::rcc::Clocks;
@@ -85,8 +85,8 @@ pub trait Pins<I2C> {
 
 impl<I2C, SCL, SDA, const SCLA: u8, const SDAA: u8> Pins<I2C> for (SCL, SDA)
 where
-    SCL: PinA<Scl, I2C, A = Const<SCLA>> + SetAlternate<SCLA, OpenDrain>,
-    SDA: PinA<Sda, I2C, A = Const<SDAA>> + SetAlternate<SDAA, OpenDrain>,
+    SCL: PinA<Scl, I2C, A = { SCLA }> + SetAlternate<SCLA, OpenDrain>,
+    SDA: PinA<Sda, I2C, A = { SDAA }> + SetAlternate<SDAA, OpenDrain>,
 {
     fn set_alt_mode(&mut self) {
         self.0.set_alt_mode();

src/i2s.rs

@@ -3,7 +3,7 @@
 //! This module is only available if the `i2s` feature is enabled.
 
 use crate::gpio::marker::{Interruptable, Readable};
-use crate::gpio::{Const, NoPin, Pin, PinA, PushPull, SetAlternate};
+use crate::gpio::{NoPin, Pin, PinA, PushPull, SetAlternate};
 use crate::pac::{self, RCC};
 use crate::rcc;
 use crate::rcc::Clocks;
@@ -85,10 +85,10 @@ impl<
         const SDA: u8,
     > Pins<SPI> for (Pin<WSP, WSN, WSM>, CK, MCLK, SD)
 where
-    Pin<WSP, WSN, WSM>: PinA<Ws, SPI, A = Const<WSA>> + SetAlternate<WSA, PushPull>,
-    CK: PinA<Ck, SPI, A = Const<CKA>> + SetAlternate<CKA, PushPull>,
-    MCLK: PinA<Mck, SPI, A = Const<MCLKA>> + SetAlternate<MCLKA, PushPull>,
-    SD: PinA<Sd, SPI, A = Const<SDA>> + SetAlternate<SDA, PushPull>,
+    Pin<WSP, WSN, WSM>: PinA<Ws, SPI, A = { WSA }> + SetAlternate<WSA, PushPull>,
+    CK: PinA<Ck, SPI, A = { CKA }> + SetAlternate<CKA, PushPull>,
+    MCLK: PinA<Mck, SPI, A = { MCLKA }> + SetAlternate<MCLKA, PushPull>,
+    SD: PinA<Sd, SPI, A = { SDA }> + SetAlternate<SDA, PushPull>,
 {
     type WsPin = Pin<WSP, WSN, Ws>;
     fn set_alt_mode(&mut self) {

src/lib.rs

@@ -1,5 +1,6 @@
 #![no_std]
 #![allow(non_camel_case_types)]
+#![feature(associated_const_equality)]
 
 #[cfg(not(feature = "device-selected"))]
 compile_error!(

src/serial.rs

@@ -26,7 +26,7 @@ use nb::block;
 mod hal_02;
 mod hal_1;
 
-use crate::gpio::{Const, PinA, PushPull, SetAlternate};
+use crate::gpio::{PinA, PushPull, SetAlternate};
 
 use crate::pac::{self, RCC};
 
@@ -191,8 +191,8 @@ pub trait Pins<USART> {
 }
 impl<USART, TX, RX, const TXA: u8, const RXA: u8> Pins<USART> for (TX, RX)
 where
-    TX: PinA<TxPin, USART, A = Const<TXA>> + SetAlternate<TXA, PushPull>,
-    RX: PinA<RxPin, USART, A = Const<RXA>> + SetAlternate<RXA, PushPull>,
+    TX: PinA<TxPin, USART, A = { TXA }> + SetAlternate<TXA, PushPull>,
+    RX: PinA<RxPin, USART, A = { RXA }> + SetAlternate<RXA, PushPull>,
 {
     fn set_alt_mode(&mut self) {
         self.0.set_alt_mode();

src/spi.rs

@@ -3,7 +3,7 @@ use core::ops::Deref;
 use core::ptr;
 
 use crate::dma::traits::PeriAddress;
-use crate::gpio::{Const, NoPin, PinA, PushPull, SetAlternate};
+use crate::gpio::{NoPin, PinA, PushPull, SetAlternate};
 use crate::pac;
 
 /// Clock polarity
@@ -72,9 +72,9 @@ pub trait Pins<SPI> {
 impl<SPI, SCK, MISO, MOSI, const SCKA: u8, const MISOA: u8, const MOSIA: u8> Pins<SPI>
     for (SCK, MISO, MOSI)
 where
-    SCK: PinA<Sck, SPI, A = Const<SCKA>> + SetAlternate<SCKA, PushPull>,
-    MISO: PinA<Miso, SPI, A = Const<MISOA>> + SetAlternate<MISOA, PushPull>,
-    MOSI: PinA<Mosi, SPI, A = Const<MOSIA>> + SetAlternate<MOSIA, PushPull>,
+    SCK: PinA<Sck, SPI, A = { SCKA }> + SetAlternate<SCKA, PushPull>,
+    MISO: PinA<Miso, SPI, A = { MISOA }> + SetAlternate<MISOA, PushPull>,
+    MOSI: PinA<Mosi, SPI, A = { MOSIA }> + SetAlternate<MOSIA, PushPull>,
 {
     fn set_alt_mode(&mut self) {
         self.0.set_alt_mode();