Stub in RNG impl.

embassy-stm32/src/rng.rs

@@ -0,0 +1,54 @@
+use crate::pac::rng_v1::{regs, Rng};
+use crate::peripherals;
+use embassy::util::Unborrow;
+use embassy_extras::unborrow;
+
+pub struct Random<T: Instance> {
+    inner: T,
+}
+
+impl<T: Instance> Random<T> {
+    pub fn new(inner: impl Unborrow<Target=T>) -> Self {
+        unborrow!(inner);
+        Self {
+            inner,
+        }
+    }
+}
+
+use embassy::traits::rng::Rng as RngTrait;
+use core::future::Future;
+use core::marker::PhantomData;
+
+impl<T:Instance> RngTrait for Random<T> {
+    type Error = ();
+    type RngFuture<'a> where Self: 'a = impl Future<Output=Result<(), Self::Error>>;
+
+    fn fill<'a>(&'a mut self, dest: &'a mut [u8]) -> Self::RngFuture<'a> {
+        async move {
+            Ok(())
+        }
+    }
+}
+
+pub(crate) mod sealed {
+    use super::*;
+
+    pub trait Instance {
+        fn regs(&self) -> Rng;
+    }
+}
+
+pub trait Instance: sealed::Instance {}
+
+macro_rules! impl_rng {
+    ($addr:expr) => {
+        impl crate::rng::sealed::Instance for peripherals::RNG {
+            fn regs(&self) -> crate::pac::rng_v1::Rng {
+                crate::pac::rng_v1::Rng($addr as _)
+            }
+        }
+
+        impl crate::rng::Instance for peripherals::RNG {}
+    }
+}