Adjust pin-names to FooPin.

Move common bits up to spi/mod.rs.
Isolate the RNG interrupt in a sub-module to avoid conflict with the const.

embassy-stm32/src/spi/mod.rs

@@ -6,6 +6,12 @@ mod spi;
 
 pub use spi::*;
 
+pub enum Error {
+    Framing,
+    Crc,
+    Overrun,
+}
+
 // TODO move upwards in the tree
 pub enum ByteOrder {
     LsbFirst,
@@ -32,3 +38,64 @@ impl Default for Config {
         }
     }
 }
+
+pub(crate) mod sealed {
+    use super::*;
+    use crate::gpio::Pin;
+    use embassy::util::AtomicWaker;
+
+    pub trait Instance {
+        fn regs() -> &'static crate::pac::spi::Spi;
+    }
+
+    pub trait SckPin<T: Instance>: Pin {
+        const AF: u8;
+        fn af(&self) -> u8 {
+            Self::AF
+        }
+    }
+
+    pub trait MosiPin<T: Instance>: Pin {
+        const AF: u8;
+        fn af(&self) -> u8 {
+            Self::AF
+        }
+    }
+
+    pub trait MisoPin<T: Instance>: Pin {
+        const AF: u8;
+        fn af(&self) -> u8 {
+            Self::AF
+        }
+    }
+}
+
+pub trait Instance: sealed::Instance + 'static {}
+
+pub trait SckPin<T: Instance>: sealed::SckPin<T> + 'static {}
+
+pub trait MosiPin<T: Instance>: sealed::MosiPin<T> + 'static {}
+
+pub trait MisoPin<T: Instance>: sealed::MisoPin<T> + 'static {}
+
+macro_rules! impl_spi {
+    ($inst:ident, $clk:ident) => {
+        impl crate::spi::sealed::Instance for peripherals::$inst {
+            fn regs() -> &'static crate::pac::spi::Spi {
+                &crate::pac::$inst
+            }
+        }
+
+        impl crate::spi::Instance for peripherals::$inst {}
+    };
+}
+
+macro_rules! impl_spi_pin {
+    ($inst:ident, $pin_func:ident, $pin:ident, $af:expr) => {
+        impl crate::spi::$pin_func<peripherals::$inst> for peripherals::$pin {}
+
+        impl crate::spi::sealed::$pin_func<peripherals::$inst> for peripherals::$pin {
+            const AF: u8 = $af;
+        }
+    };
+}