4 files changed, 11 insertions, 2 deletions

diff --git a/embassy-stm32/Cargo.toml b/embassy-stm32/Cargo.toml
index 0bbe38cfe..7fce5b87a 100644
--- a/embassy-stm32/Cargo.toml
+++ b/embassy-stm32/Cargo.toml
@@ -31,6 +31,9 @@ defmt-info = [ ]
 defmt-warn = [ ]
 defmt-error = [ ]
 sdmmc-rs = ["embedded-sdmmc"]
+# Unstable feature to give access to the pac used in embassy-stm32, changes with this feature don't
+# follow semver
+pac = []
 
 # BEGIN GENERATED FEATURES
 stm32f401cb = [ "_dma", "_dma_v2", "_exti", "_exti_v1", "_gpio", "_gpio_v2", "_spi", "_spi_v1", "_stm32f4", "_syscfg", "_syscfg_f4", "_usart", "_usart_v1",]
diff --git a/embassy-stm32/gen.py b/embassy-stm32/gen.py
index ba674207d..05cc3d3b7 100644
--- a/embassy-stm32/gen.py
+++ b/embassy-stm32/gen.py
@@ -42,7 +42,8 @@ with open('src/pac/mod.rs', 'w') as f:
             f'#[cfg_attr(feature="{chip["name"]}", path="{chip["name"]}.rs")]\n')
     f.write('mod chip;\n')
     f.write('pub use chip::*;\n')
-    f.write('pub(crate) mod regs;\n')
+    f.write('#[allow(dead_code, unused_imports)]\n')
+    f.write('pub mod regs;\n')
 
 # ========= Generate pac/stm32xxx.rs
 
diff --git a/embassy-stm32/src/lib.rs b/embassy-stm32/src/lib.rs
index 2fc07cd5e..8f8dd753b 100644
--- a/embassy-stm32/src/lib.rs
+++ b/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;
diff --git a/embassy-stm32/src/pac/mod.rs b/embassy-stm32/src/pac/mod.rs
index 4f629e33d..8ed31d7b4 100644
--- a/embassy-stm32/src/pac/mod.rs
+++ b/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;