Add unstable feature to give access to the pac

embassy-stm32/src/lib.rs

@@ -25,7 +25,11 @@ pub mod spi;
 pub mod usart;
 
 // This must go LAST so that it sees the `impl_foo!` macros
+#[cfg(feature = "pac")]
 pub mod pac;
+
+#[cfg(not(feature = "pac"))]
+mod pac;
 pub mod time;
 
 pub use embassy_macros::interrupt;

embassy-stm32/src/pac/mod.rs

@@ -503,4 +503,5 @@
 #[cfg_attr(feature = "stm32l4s9zi", path = "stm32l4s9zi.rs")]
 mod chip;
 pub use chip::*;
-pub(crate) mod regs;
+#[allow(dead_code, unused_imports)]
+pub mod regs;