3 files changed, 202 insertions, 10 deletions

diff --git a/embassy-stm32/build.rs b/embassy-stm32/build.rs
index fa10b7f77..5b6b22ea1 100644
--- a/embassy-stm32/build.rs
+++ b/embassy-stm32/build.rs
@@ -5,7 +5,8 @@ use std::{env, fs};
 
 use proc_macro2::{Ident, TokenStream};
 use quote::{format_ident, quote};
-use stm32_metapac::metadata::{MemoryRegionKind, METADATA};
+use stm32_metapac::metadata::ir::{BlockItemInner, Enum};
+use stm32_metapac::metadata::{MemoryRegionKind, PeripheralRccRegister, METADATA};
 
 fn main() {
     let target = env::var("TARGET").unwrap();
@@ -388,6 +389,51 @@ fn main() {
     }
 
     // ========
+    // Generate rcc fieldset and enum maps
+    let rcc_enum_map: HashMap<&str, HashMap<&str, &Enum>> = {
+        let rcc_registers = METADATA
+            .peripherals
+            .iter()
+            .filter_map(|p| p.registers.as_ref())
+            .find(|r| r.kind == "rcc")
+            .unwrap()
+            .ir;
+
+        let rcc_blocks = rcc_registers.blocks.iter().find(|b| b.name == "Rcc").unwrap().items;
+
+        let rcc_block_item_map: HashMap<&str, &str> = rcc_blocks
+            .iter()
+            .filter_map(|b| match &b.inner {
+                BlockItemInner::Register(register) => register.fieldset.map(|f| (f, b.name)),
+                _ => None,
+            })
+            .collect();
+
+        let rcc_enum_map: HashMap<&str, &Enum> = rcc_registers.enums.iter().map(|e| (e.name, e)).collect();
+
+        rcc_registers
+            .fieldsets
+            .iter()
+            .filter_map(|f| {
+                rcc_block_item_map.get(f.name).map(|b| {
+                    (
+                        *b,
+                        f.fields
+                            .iter()
+                            .filter_map(|f| {
+                                let enumm = f.enumm?;
+                                let enumm = rcc_enum_map.get(enumm)?;
+
+                                Some((f.name, *enumm))
+                            })
+                            .collect(),
+                    )
+                })
+            })
+            .collect()
+    };
+
+    // ========
     // Generate RccPeripheral impls
 
     let refcounted_peripherals = HashSet::from(["usart", "adc"]);
@@ -454,10 +500,61 @@ fn main() {
                 (TokenStream::new(), TokenStream::new())
             };
 
+            let mux_for = |mux: Option<&'static PeripheralRccRegister>| {
+                // temporary hack to restrict the scope of the implementation to h5
+                if !&chip_name.starts_with("stm32h5") {
+                    return None;
+                }
+
+                let mux = mux?;
+                let fieldset = rcc_enum_map.get(mux.register)?;
+                let enumm = fieldset.get(mux.field)?;
+
+                Some((mux, *enumm))
+            };
+
+            let clock_frequency = match mux_for(rcc.mux.as_ref()) {
+                Some((mux, rcc_enumm)) => {
+                    let fieldset_name = format_ident!("{}", mux.register);
+                    let field_name = format_ident!("{}", mux.field);
+                    let enum_name = format_ident!("{}", rcc_enumm.name);
+
+                    let match_arms: TokenStream = rcc_enumm
+                        .variants
+                        .iter()
+                        .filter(|v| v.name != "DISABLE")
+                        .map(|v| {
+                            let variant_name = format_ident!("{}", v.name);
+
+                            // temporary hack to restrict the scope of the implementation until clock names can be stabilized
+                            let clock_name = format_ident!("mux_{}", v.name.to_ascii_lowercase());
+
+                            quote! {
+                                #enum_name::#variant_name => unsafe { crate::rcc::get_freqs().#clock_name.unwrap() },
+                            }
+                        })
+                        .collect();
+
+                    quote! {
+                        use crate::pac::rcc::vals::#enum_name;
+
+                        #[allow(unreachable_patterns)]
+                        match crate::pac::RCC.#fieldset_name().read().#field_name() {
+                            #match_arms
+
+                            _ => unreachable!(),
+                        }
+                    }
+                }
+                None => quote! {
+                    unsafe { crate::rcc::get_freqs().#clk }
+                },
+            };
+
             g.extend(quote! {
                 impl crate::rcc::sealed::RccPeripheral for peripherals::#pname {
                     fn frequency() -> crate::time::Hertz {
-                        unsafe { crate::rcc::get_freqs().#clk }
+                        #clock_frequency
                     }
                     fn enable() {
                         critical_section::with(|_cs| {
@@ -486,12 +583,14 @@ fn main() {
         }
     }
 
-    let mut refcount_mod = TokenStream::new();
-    for refcount_static in refcount_statics {
-        refcount_mod.extend(quote! {
-            pub(crate) static mut #refcount_static: u8 = 0;
-        });
-    }
+    let refcount_mod: TokenStream = refcount_statics
+        .iter()
+        .map(|refcount_static| {
+            quote! {
+                pub(crate) static mut #refcount_static: u8 = 0;
+            }
+        })
+        .collect();
 
     g.extend(quote! {
         mod refcount_statics {
diff --git a/embassy-stm32/src/rcc/h.rs b/embassy-stm32/src/rcc/h.rs
index 7236d82ff..d37dd45d4 100644
--- a/embassy-stm32/src/rcc/h.rs
+++ b/embassy-stm32/src/rcc/h.rs
@@ -388,7 +388,7 @@ pub(crate) unsafe fn init(config: Config) {
     let pll1 = init_pll(0, config.pll1, &pll_input);
     let pll2 = init_pll(1, config.pll2, &pll_input);
     #[cfg(any(rcc_h5, stm32h7))]
-    let _pll3 = init_pll(2, config.pll3, &pll_input);
+    let pll3 = init_pll(2, config.pll3, &pll_input);
 
     // Configure sysclk
     let (sys, sw) = match config.sys {
@@ -447,7 +447,7 @@ pub(crate) unsafe fn init(config: Config) {
     #[cfg(stm32h7)]
     let adc = match config.adc_clock_source {
         AdcClockSource::PLL2_P => pll2.p,
-        AdcClockSource::PLL3_R => _pll3.r,
+        AdcClockSource::PLL3_R => pll3.r,
         AdcClockSource::PER => _per_ck,
         _ => unreachable!(),
     };
@@ -545,6 +545,53 @@ pub(crate) unsafe fn init(config: Config) {
         apb2_tim,
         adc,
         rtc,
+
+        #[cfg(stm32h5)]
+        mux_rcc_pclk1: Some(apb1),
+        #[cfg(stm32h5)]
+        mux_pll2_q: None,
+        #[cfg(stm32h5)]
+        mux_pll3_q: None,
+        #[cfg(stm32h5)]
+        mux_hsi_ker: None,
+        #[cfg(stm32h5)]
+        mux_csi_ker: None,
+        #[cfg(stm32h5)]
+        mux_lse: None,
+        #[cfg(stm32h5)]
+        mux_pll1_q: pll1.q,
+        #[cfg(stm32h5)]
+        mux_pll2_p: pll2.p,
+        #[cfg(rcc_h5)]
+        mux_pll3_p: pll3.p,
+        #[cfg(stm32h5)]
+        mux_audioclk: None,
+        #[cfg(stm32h5)]
+        mux_per: None,
+
+        #[cfg(rcc_h5)]
+        mux_pll3_r: pll3.r,
+        #[cfg(all(not(rcc_h5), stm32h5))]
+        mux_pll3_r: None,
+        #[cfg(stm32h5)]
+        mux_rcc_pclk3: Some(apb3),
+        #[cfg(stm32h5)]
+        mux_pll3_1: None,
+        #[cfg(stm32h5)]
+        mux_hsi48_ker: None,
+        #[cfg(stm32h5)]
+        mux_lsi_ker: None,
+        #[cfg(stm32h5)]
+        mux_pll2_r: pll2.r,
+        #[cfg(stm32h5)]
+        mux_rcc_pclk2: Some(apb2),
+        #[cfg(stm32h5)]
+        mux_rcc_pclk4: None,
+        #[cfg(stm32h5)]
+        mux_hse: hse,
+
+        #[cfg(stm32h5)]
+        mux_hsi48: None,
     });
 }
 
diff --git a/embassy-stm32/src/rcc/mod.rs b/embassy-stm32/src/rcc/mod.rs
index abb53fd10..695d41589 100644
--- a/embassy-stm32/src/rcc/mod.rs
+++ b/embassy-stm32/src/rcc/mod.rs
@@ -134,6 +134,52 @@ pub struct Clocks {
     pub hrtim: Option<Hertz>,
 
     pub rtc: Option<Hertz>,
+
+    #[cfg(stm32h5)]
+    pub mux_rcc_pclk1: Option<Hertz>,
+    #[cfg(stm32h5)]
+    pub mux_pll2_q: Option<Hertz>,
+    #[cfg(stm32h5)]
+    pub mux_pll3_q: Option<Hertz>,
+    #[cfg(stm32h5)]
+    pub mux_hsi_ker: Option<Hertz>,
+    #[cfg(stm32h5)]
+    pub mux_csi_ker: Option<Hertz>,
+    #[cfg(stm32h5)]
+    pub mux_lse: Option<Hertz>,
+
+    #[cfg(stm32h5)]
+    pub mux_pll1_q: Option<Hertz>,
+    #[cfg(stm32h5)]
+    pub mux_pll2_p: Option<Hertz>,
+    #[cfg(rcc_h5)]
+    pub mux_pll3_p: Option<Hertz>,
+    #[cfg(stm32h5)]
+    pub mux_audioclk: Option<Hertz>,
+    #[cfg(stm32h5)]
+    pub mux_per: Option<Hertz>,
+
+    #[cfg(stm32h5)]
+    pub mux_pll3_r: Option<Hertz>,
+    #[cfg(stm32h5)]
+    pub mux_rcc_pclk3: Option<Hertz>,
+    #[cfg(stm32h5)]
+    pub mux_pll3_1: Option<Hertz>,
+    #[cfg(stm32h5)]
+    pub mux_hsi48_ker: Option<Hertz>,
+    #[cfg(stm32h5)]
+    pub mux_lsi_ker: Option<Hertz>,
+    #[cfg(stm32h5)]
+    pub mux_pll2_r: Option<Hertz>,
+    #[cfg(stm32h5)]
+    pub mux_rcc_pclk2: Option<Hertz>,
+    #[cfg(stm32h5)]
+    pub mux_rcc_pclk4: Option<Hertz>,
+    #[cfg(stm32h5)]
+    pub mux_hse: Option<Hertz>,
+
+    #[cfg(stm32h5)]
+    pub mux_hsi48: Option<Hertz>,
 }
 
 #[cfg(feature = "low-power")]