Re-adds embassy macros for stm32

* Hook RCC config into chip config and use chip-specific RCC init
  function
* RTC/clock setup is ignored for now

embassy-stm32/Cargo.toml

@@ -6,7 +6,7 @@ edition = "2018"
 
 [dependencies]
 embassy = { version = "0.1.0", path = "../embassy" }
-embassy-macros = { version = "0.1.0", path = "../embassy-macros" }
+embassy-macros = { version = "0.1.0", path = "../embassy-macros", features = ["stm32"] }
 embassy-extras = {version = "0.1.0", path = "../embassy-extras" }
 embassy-traits = {version = "0.1.0", path = "../embassy-traits" }
 
@@ -23,6 +23,8 @@ critical-section = "0.2.1"
 bare-metal = "1.0.0"
 atomic-polyfill = "0.1.2"
 
+cfg-if = "1.0.0"
+
 [build-dependencies]
 regex = "1.4.6"
 

embassy-stm32/src/lib.rs

@@ -42,22 +42,25 @@ pub(crate) use pac::regs::generic;
 
 #[non_exhaustive]
 pub struct Config {
-    _private: (),
+    rcc: rcc::Config,
 }
 
 impl Default for Config {
     fn default() -> Self {
-        Self { _private: () }
+        Self {
+            rcc: Default::default(),
+        }
     }
 }
 
 /// Initialize embassy.
-pub fn init(_config: Config) -> Peripherals {
+pub fn init(config: Config) -> Peripherals {
     let p = Peripherals::take();
 
     unsafe {
         dma::init();
         pac::init_exti();
+        rcc::init(config.rcc);
     }
 
     p

embassy-stm32/src/rcc/h7/mod.rs

@@ -527,3 +527,7 @@ impl<'d> Rcc<'d> {
         }
     }
 }
+
+pub unsafe fn init(config: Config) {
+    // TODO
+}

embassy-stm32/src/rcc/mod.rs

@@ -1,4 +1,13 @@
-#[cfg(feature = "_stm32h7")]
-mod h7;
-#[cfg(feature = "_stm32h7")]
-pub use h7::*;
+cfg_if::cfg_if! {
+    if #[cfg(feature = "_stm32h7")] {
+        mod h7;
+        pub use h7::*;
+    } else if #[cfg(feature = "_stm32l0")] {
+        mod l0;
+        pub use l0::*;
+    } else {
+        #[derive(Default)]
+        pub struct Config {}
+        pub fn init(_config: Config) {}
+    }
+}