Move clocks to rcc mod

embassy-stm32/src/rcc/mod.rs

@@ -1,3 +1,35 @@
+use crate::time::Hertz;
+use core::mem::MaybeUninit;
+
+/// Frozen clock frequencies
+///
+/// The existence of this value indicates that the clock configuration can no longer be changed
+#[derive(Clone, Copy)]
+pub struct Clocks {
+    pub sys_clk: Hertz,
+    pub ahb_clk: Hertz,
+    pub apb1_clk: Hertz,
+    pub apb1_tim_clk: Hertz,
+    pub apb2_clk: Hertz,
+    pub apb2_tim_clk: Hertz,
+    pub apb1_pre: u8,
+    pub apb2_pre: u8,
+}
+
+static mut CLOCK_FREQS: MaybeUninit<Clocks> = MaybeUninit::uninit();
+
+/// Sets the clock frequencies
+///
+/// Safety: Sets a mutable global.
+pub unsafe fn set_freqs(freqs: Clocks) {
+    CLOCK_FREQS.as_mut_ptr().write(freqs);
+}
+
+/// Safety: Reads a mutable global.
+pub unsafe fn get_freqs() -> &'static Clocks {
+    &*CLOCK_FREQS.as_ptr()
+}
+
 cfg_if::cfg_if! {
     if #[cfg(feature = "_stm32h7")] {
         mod h7;