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

#![macro_use]

use crate::peripherals;
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: Hertz,
    pub ahb: Hertz,
    pub apb1: Hertz,
    pub apb2: Hertz,
}

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(rcc_h7)] {
        mod h7;
        pub use h7::*;
    } else if #[cfg(rcc_l0)] {
        mod l0;
        pub use l0::*;
    } else {
        #[derive(Default)]
        pub struct Config {}
        pub unsafe fn init(_config: Config) {
        }
    }
}

pub(crate) mod sealed {
    pub trait RccPeripheral {
        fn frequency() -> crate::time::Hertz;
        fn reset();
        fn enable();
        fn disable();
    }
}

pub trait RccPeripheral: sealed::RccPeripheral + 'static {}

crate::pac::peripheral_rcc!(
    ($inst:ident, $clk:ident, $enable:ident, $reset:ident, $perien:ident, $perirst:ident) => {
        impl sealed::RccPeripheral for peripherals::$inst {
            fn frequency() -> crate::time::Hertz {
                critical_section::with(|_| {
                    unsafe {
                        let freqs = get_freqs();
                        freqs.$clk
                    }
                })
            }
            fn enable() {
                critical_section::with(|_| {
                    unsafe {
                        crate::pac::RCC.$enable().modify(|w| w.$perien(true));
                    }
                })
            }
            fn disable() {
                critical_section::with(|_| {
                    unsafe {
                        crate::pac::RCC.$enable().modify(|w| w.$perien(false));
                    }
                })
            }
            fn reset() {
                critical_section::with(|_| {
                    unsafe {
                        crate::pac::RCC.$reset().modify(|w| w.$perirst(true));
                        crate::pac::RCC.$reset().modify(|w| w.$perirst(false));
                    }
                })
            }
        }

        impl RccPeripheral for peripherals::$inst {}
    };
);