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-macros/Cargo.toml

@@ -15,5 +15,6 @@ proc-macro = true
 
 [features]
 nrf = []
+stm32 = []
 rp = []
 std = []

embassy-macros/src/chip/stm32.rs

@@ -0,0 +1,26 @@
+use crate::path::ModulePrefix;
+use proc_macro2::TokenStream;
+use quote::quote;
+
+pub fn generate(embassy_prefix: &ModulePrefix, config: syn::Expr) -> TokenStream {
+    let embassy_path = embassy_prefix.append("embassy").path();
+    let embassy_stm32_path = embassy_prefix.append("embassy_stm32").path();
+
+    quote!(
+        use #embassy_stm32_path::{clock::Clock};
+
+        let p = #embassy_stm32_path::init(#config);
+
+        /*
+        let mut rtc = #embass::RTC::new(unsafe { <peripherals::TIM2 as #embassy_path::util::Steal>::steal() }, interrupt::take!(TIM2));
+        let rtc = unsafe { make_static(&mut rtc) };
+        rtc.start();
+        let mut alarm = rtc.alarm0();
+
+        unsafe { #embassy_path::time::set_clock(rtc) };
+
+        let alarm = unsafe { make_static(&mut alarm) };
+        executor.set_alarm(alarm);
+        */
+    )
+}

embassy-macros/src/lib.rs

@@ -256,6 +256,10 @@ pub fn interrupt_take(item: TokenStream) -> TokenStream {
     result.into()
 }
 
+#[cfg(feature = "stm32")]
+#[path = "chip/stm32.rs"]
+mod chip;
+
 #[cfg(feature = "nrf")]
 #[path = "chip/nrf.rs"]
 mod chip;
@@ -273,7 +277,7 @@ struct MainArgs {
     config: Option<syn::LitStr>,
 }
 
-#[cfg(any(feature = "nrf", feature = "rp"))]
+#[cfg(any(feature = "nrf", feature = "rp", feature = "stm32"))]
 #[proc_macro_attribute]
 pub fn main(args: TokenStream, item: TokenStream) -> TokenStream {
     let macro_args = syn::parse_macro_input!(args as syn::AttributeArgs);

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) {}
+    }
+}