10 files changed, 350 insertions, 411 deletions

diff --git a/embassy-stm32/Cargo.toml b/embassy-stm32/Cargo.toml
index 3f5f12f06..24af17327 100644
--- a/embassy-stm32/Cargo.toml
+++ b/embassy-stm32/Cargo.toml
@@ -68,7 +68,7 @@ rand_core = "0.6.3"
 sdio-host = "0.5.0"
 critical-section = "1.1"
 #stm32-metapac = { version = "15" }
-stm32-metapac = { git = "https://github.com/embassy-rs/stm32-data-generated", tag = "stm32-data-5bf4bec597bdf0d85402789b40c3a37b0f5a8e76" }
+stm32-metapac = { git = "https://github.com/embassy-rs/stm32-data-generated", tag = "stm32-data-8ae5bb5fe696a7e61fb41b8b797372aed8103a82" }
 vcell = "0.1.3"
 bxcan = "0.7.0"
 nb = "1.0.0"
@@ -89,7 +89,7 @@ critical-section = { version = "1.1", features = ["std"] }
 proc-macro2 = "1.0.36"
 quote = "1.0.15"
 #stm32-metapac = { version = "15", default-features = false, features = ["metadata"]}
-stm32-metapac = { git = "https://github.com/embassy-rs/stm32-data-generated", tag = "stm32-data-5bf4bec597bdf0d85402789b40c3a37b0f5a8e76", default-features = false, features = ["metadata"]}
+stm32-metapac = { git = "https://github.com/embassy-rs/stm32-data-generated", tag = "stm32-data-8ae5bb5fe696a7e61fb41b8b797372aed8103a82", default-features = false, features = ["metadata"]}
 
 
 [features]
diff --git a/embassy-stm32/src/rcc/f3.rs b/embassy-stm32/src/rcc/f3.rs
index 25866e446..0a5e67b4a 100644
--- a/embassy-stm32/src/rcc/f3.rs
+++ b/embassy-stm32/src/rcc/f3.rs
@@ -1,208 +1,230 @@
-#[cfg(rcc_f3)]
-use crate::pac::adccommon::vals::Ckmode;
 use crate::pac::flash::vals::Latency;
-pub use crate::pac::rcc::vals::Adcpres;
-use crate::pac::rcc::vals::{Hpre, Pllmul, Pllsrc, Ppre, Prediv, Sw, Usbpre};
+pub use crate::pac::rcc::vals::{
+    Adcpres as AdcPllPrescaler, Hpre as AHBPrescaler, Pllmul as PllMul, Ppre as APBPrescaler, Prediv as PllPreDiv,
+    Sw as Sysclk,
+};
+use crate::pac::rcc::vals::{Pllsrc, Usbpre};
 use crate::pac::{FLASH, RCC};
 use crate::time::Hertz;
 
 /// HSI speed
 pub const HSI_FREQ: Hertz = Hertz(8_000_000);
 
-#[cfg(rcc_f3)]
-impl From<AdcClockSource> for Ckmode {
-    fn from(value: AdcClockSource) -> Self {
-        match value {
-            AdcClockSource::BusDiv1 => Ckmode::SYNCDIV1,
-            AdcClockSource::BusDiv2 => Ckmode::SYNCDIV2,
-            AdcClockSource::BusDiv4 => Ckmode::SYNCDIV4,
-            _ => unreachable!(),
-        }
-    }
+#[derive(Clone, Copy, Eq, PartialEq)]
+pub enum HseMode {
+    /// crystal/ceramic oscillator (HSEBYP=0)
+    Oscillator,
+    /// external analog clock (low swing) (HSEBYP=1)
+    Bypass,
+}
+
+#[derive(Clone, Copy, Eq, PartialEq)]
+pub struct Hse {
+    /// HSE frequency.
+    pub freq: Hertz,
+    /// HSE mode.
+    pub mode: HseMode,
+}
+
+#[derive(Clone, Copy, Eq, PartialEq)]
+pub enum PllSource {
+    HSE,
+    HSI,
+}
+
+#[derive(Clone, Copy)]
+pub struct Pll {
+    pub src: PllSource,
+
+    /// PLL pre-divider.
+    ///
+    /// On some F3 chips, this must be 2 if `src == HSI`. Init will panic if this is not the case.
+    pub prediv: PllPreDiv,
+
+    /// PLL multiplication factor.
+    pub mul: PllMul,
 }
 
 #[derive(Clone, Copy)]
 pub enum AdcClockSource {
-    Pll(Adcpres),
-    BusDiv1,
-    BusDiv2,
-    BusDiv4,
+    Pll(AdcPllPrescaler),
+    Hclk(AdcHclkPrescaler),
 }
 
-impl AdcClockSource {
-    pub fn bus_div(&self) -> u32 {
-        match self {
-            Self::BusDiv1 => 1,
-            Self::BusDiv2 => 2,
-            Self::BusDiv4 => 4,
-            _ => unreachable!(),
-        }
-    }
+#[derive(Clone, Copy, PartialEq, Eq)]
+pub enum AdcHclkPrescaler {
+    Div1,
+    Div2,
+    Div4,
 }
 
-#[derive(Default)]
+#[derive(Clone, Copy, PartialEq, Eq)]
 pub enum HrtimClockSource {
-    #[default]
     BusClk,
     PllClk,
 }
 
 /// Clocks configutation
 #[non_exhaustive]
-#[derive(Default)]
 pub struct Config {
-    /// Frequency of HSE oscillator
-    /// 4MHz to 32MHz
-    pub hse: Option<Hertz>,
-    /// Bypass HSE for an external clock
-    pub bypass_hse: bool,
-    /// Frequency of the System Clock
-    pub sysclk: Option<Hertz>,
-    /// Frequency of AHB bus
-    pub hclk: Option<Hertz>,
-    /// Frequency of APB1 bus
-    /// - Max frequency 36MHz
-    pub pclk1: Option<Hertz>,
-    /// Frequency of APB2 bus
-    /// - Max frequency with HSE is 72MHz
-    /// - Max frequency without HSE is 64MHz
-    pub pclk2: Option<Hertz>,
-    /// USB clock setup
-    /// It is valid only when,
-    /// - HSE is enabled,
-    /// - The System clock frequency is either 48MHz or 72MHz
-    /// - APB1 clock has a minimum frequency of 10MHz
-    pub pll48: bool,
-    #[cfg(rcc_f3)]
-    /// ADC clock setup
-    /// - For AHB, a psc of 4 or less must be used
-    pub adc: Option<AdcClockSource>,
-    #[cfg(rcc_f3)]
-    /// ADC clock setup
-    /// - For AHB, a psc of 4 or less must be used
-    pub adc34: Option<AdcClockSource>,
+    pub hsi: bool,
+    pub hse: Option<Hse>,
+    pub sys: Sysclk,
+
+    pub pll: Option<Pll>,
+
+    pub ahb_pre: AHBPrescaler,
+    pub apb1_pre: APBPrescaler,
+    pub apb2_pre: APBPrescaler,
+
+    #[cfg(not(rcc_f37))]
+    pub adc: AdcClockSource,
+    #[cfg(all(not(rcc_f37), adc3_common))]
+    pub adc34: AdcClockSource,
     #[cfg(stm32f334)]
     pub hrtim: HrtimClockSource,
+
     pub ls: super::LsConfig,
 }
 
-// Information required to setup the PLL clock
-#[derive(Clone, Copy)]
-struct PllConfig {
-    pll_src: Pllsrc,
-    pll_mul: Pllmul,
-    pll_div: Option<Prediv>,
+impl Default for Config {
+    fn default() -> Self {
+        Self {
+            hsi: true,
+            hse: None,
+            sys: Sysclk::HSI,
+            pll: None,
+            ahb_pre: AHBPrescaler::DIV1,
+            apb1_pre: APBPrescaler::DIV1,
+            apb2_pre: APBPrescaler::DIV1,
+            ls: Default::default(),
+
+            #[cfg(not(rcc_f37))]
+            adc: AdcClockSource::Hclk(AdcHclkPrescaler::Div1),
+            #[cfg(all(not(rcc_f37), adc3_common))]
+            adc34: AdcClockSource::Hclk(AdcHclkPrescaler::Div1),
+            #[cfg(stm32f334)]
+            hrtim: HrtimClockSource::BusClk,
+        }
+    }
 }
 
 /// Initialize and Set the clock frequencies
 pub(crate) unsafe fn init(config: Config) {
-    // Calculate the real System clock, and PLL configuration if applicable
-    let (sysclk, pll_config) = get_sysclk(&config);
-    assert!(sysclk.0 <= 72_000_000);
-
-    // Calculate real AHB clock
-    let hclk = config.hclk.map(|h| h).unwrap_or(sysclk);
-    let hpre = match sysclk.0 / hclk.0 {
-        0 => unreachable!(),
-        1 => Hpre::DIV1,
-        2 => Hpre::DIV2,
-        3..=5 => Hpre::DIV4,
-        6..=11 => Hpre::DIV8,
-        12..=39 => Hpre::DIV16,
-        40..=95 => Hpre::DIV64,
-        96..=191 => Hpre::DIV128,
-        192..=383 => Hpre::DIV256,
-        _ => Hpre::DIV512,
-    };
-    let hclk = sysclk / hpre;
-    assert!(hclk <= Hertz(72_000_000));
-
-    // Calculate real APB1 clock
-    let pclk1 = config.pclk1.unwrap_or(hclk);
-    let ppre1 = match hclk / pclk1 {
-        0 => unreachable!(),
-        1 => Ppre::DIV1,
-        2 => Ppre::DIV2,
-        3..=5 => Ppre::DIV4,
-        6..=11 => Ppre::DIV8,
-        _ => Ppre::DIV16,
-    };
-    let timer_mul1 = if ppre1 == Ppre::DIV1 { 1u32 } else { 2 };
-    let pclk1 = hclk / ppre1;
-    assert!(pclk1 <= Hertz(36_000_000));
-
-    // Calculate real APB2 clock
-    let pclk2 = config.pclk2.unwrap_or(hclk);
-    let ppre2 = match hclk / pclk2 {
-        0 => unreachable!(),
-        1 => Ppre::DIV1,
-        2 => Ppre::DIV2,
-        3..=5 => Ppre::DIV4,
-        6..=11 => Ppre::DIV8,
-        _ => Ppre::DIV16,
+    // Configure HSI
+    let hsi = match config.hsi {
+        false => {
+            RCC.cr().modify(|w| w.set_hsion(false));
+            None
+        }
+        true => {
+            RCC.cr().modify(|w| w.set_hsion(true));
+            while !RCC.cr().read().hsirdy() {}
+            Some(HSI_FREQ)
+        }
     };
-    let timer_mul2 = if ppre2 == Ppre::DIV1 { 1u32 } else { 2 };
-    let pclk2 = hclk / ppre2;
-    assert!(pclk2 <= Hertz(72_000_000));
 
-    // Set latency based on HCLK frquency
-    // RM0316: "The prefetch buffer must be kept on when using a prescaler
-    // different from 1 on the AHB clock.", "Half-cycle access cannot be
-    // used when there is a prescaler different from 1 on the AHB clock"
-    FLASH.acr().modify(|w| {
-        w.set_latency(if hclk <= Hertz(24_000_000) {
-            Latency::WS0
-        } else if hclk <= Hertz(48_000_000) {
-            Latency::WS1
-        } else {
-            Latency::WS2
-        });
-        if hpre != Hpre::DIV1 {
-            w.set_hlfcya(false);
-            w.set_prftbe(true);
+    // Configure HSE
+    let hse = match config.hse {
+        None => {
+            RCC.cr().modify(|w| w.set_hseon(false));
+            None
         }
-    });
+        Some(hse) => {
+            match hse.mode {
+                HseMode::Bypass => assert!(max::HSE_BYP.contains(&hse.freq)),
+                HseMode::Oscillator => assert!(max::HSE_OSC.contains(&hse.freq)),
+            }
 
-    // Enable HSE
-    // RM0316: "Bits 31:26 Reserved, must be kept at reset value."
-    if config.hse.is_some() {
-        RCC.cr().modify(|w| {
-            w.set_hsebyp(config.bypass_hse);
-            // We turn on clock security to switch to HSI when HSE fails
-            w.set_csson(true);
-            w.set_hseon(true);
-        });
-        while !RCC.cr().read().hserdy() {}
-    }
+            RCC.cr().modify(|w| w.set_hsebyp(hse.mode != HseMode::Oscillator));
+            RCC.cr().modify(|w| w.set_hseon(true));
+            while !RCC.cr().read().hserdy() {}
+            Some(hse.freq)
+        }
+    };
 
     // Enable PLL
     // RM0316: "Reserved, must be kept at reset value."
-    if let Some(ref pll_config) = pll_config {
+    let pll = config.pll.map(|pll| {
+        let (src_val, src_freq) = match pll.src {
+            #[cfg(rcc_f3v3)]
+            PllSource::HSI => (Pllsrc::HSI_DIV_PREDIV, unwrap!(hsi)),
+            #[cfg(not(rcc_f3v3))]
+            PllSource::HSI => {
+                if pll.prediv != PllPreDiv::DIV2 {
+                    panic!("if PLL source is HSI, PLL prediv must be 2.");
+                }
+                (Pllsrc::HSI_DIV2, unwrap!(hsi))
+            }
+            PllSource::HSE => (Pllsrc::HSE_DIV_PREDIV, unwrap!(hse)),
+        };
+        let in_freq = src_freq / pll.prediv;
+        assert!(max::PLL_IN.contains(&in_freq));
+        let out_freq = in_freq * pll.mul;
+        assert!(max::PLL_OUT.contains(&out_freq));
+
+        RCC.cfgr2().modify(|w| w.set_prediv(pll.prediv));
         RCC.cfgr().modify(|w| {
-            w.set_pllmul(pll_config.pll_mul);
-            w.set_pllsrc(pll_config.pll_src);
+            w.set_pllmul(pll.mul);
+            w.set_pllsrc(src_val);
         });
-        if let Some(pll_div) = pll_config.pll_div {
-            RCC.cfgr2().modify(|w| w.set_prediv(pll_div));
-        }
         RCC.cr().modify(|w| w.set_pllon(true));
         while !RCC.cr().read().pllrdy() {}
-    }
 
-    // CFGR has been written before (PLL) don't overwrite these settings
-    if config.pll48 {
-        let usb_pre = get_usb_pre(&config, sysclk, pclk1, &pll_config);
-        RCC.cfgr().modify(|w| {
-            w.set_usbpre(usb_pre);
-        });
-    }
+        out_freq
+    });
+
+    let usb = match pll {
+        Some(Hertz(72_000_000)) => {
+            RCC.cfgr().modify(|w| w.set_usbpre(Usbpre::DIV1_5));
+            Some(Hertz(48_000_000))
+        }
+        Some(Hertz(48_000_000)) => {
+            RCC.cfgr().modify(|w| w.set_usbpre(Usbpre::DIV1));
+            Some(Hertz(48_000_000))
+        }
+        _ => None,
+    };
+
+    // Configure sysclk
+    let sys = match config.sys {
+        Sysclk::HSI => unwrap!(hsi),
+        Sysclk::HSE => unwrap!(hse),
+        Sysclk::PLL1_P => unwrap!(pll),
+        _ => unreachable!(),
+    };
+
+    let hclk = sys / config.ahb_pre;
+    let (pclk1, pclk1_tim) = super::util::calc_pclk(hclk, config.apb1_pre);
+    let (pclk2, pclk2_tim) = super::util::calc_pclk(hclk, config.apb2_pre);
+
+    assert!(max::HCLK.contains(&hclk));
+    assert!(max::PCLK1.contains(&pclk1));
+    assert!(max::PCLK2.contains(&pclk2));
+
+    // Set latency based on HCLK frquency
+    let latency = match hclk.0 {
+        ..=24_000_000 => Latency::WS0,
+        ..=48_000_000 => Latency::WS1,
+        _ => Latency::WS2,
+    };
+    FLASH.acr().modify(|w| {
+        w.set_latency(latency);
+        // RM0316: "The prefetch buffer must be kept on when using a prescaler
+        // different from 1 on the AHB clock.", "Half-cycle access cannot be
+        // used when there is a prescaler different from 1 on the AHB clock"
+        if config.ahb_pre != AHBPrescaler::DIV1 {
+            w.set_hlfcya(false);
+            w.set_prftbe(true);
+        }
+    });
 
     // Set prescalers
     // CFGR has been written before (PLL, PLL48) don't overwrite these settings
     RCC.cfgr().modify(|w| {
-        w.set_ppre2(ppre2);
-        w.set_ppre1(ppre1);
-        w.set_hpre(hpre);
+        w.set_ppre2(config.apb1_pre);
+        w.set_ppre1(config.apb2_pre);
+        w.set_hpre(config.ahb_pre);
     });
 
     // Wait for the new prescalers to kick in
@@ -211,53 +233,60 @@ pub(crate) unsafe fn init(config: Config) {
     cortex_m::asm::delay(16);
 
     // CFGR has been written before (PLL, PLL48, clock divider) don't overwrite these settings
-    RCC.cfgr().modify(|w| {
-        w.set_sw(match (pll_config, config.hse) {
-            (Some(_), _) => Sw::PLL1_P,
-            (None, Some(_)) => Sw::HSE,
-            (None, None) => Sw::HSI,
-        })
-    });
+    RCC.cfgr().modify(|w| w.set_sw(config.sys));
 
-    #[cfg(rcc_f3)]
-    let adc = config.adc.map(|adc| match adc {
+    let rtc = config.ls.init();
+
+    #[cfg(not(rcc_f37))]
+    use crate::pac::adccommon::vals::Ckmode;
+
+    #[cfg(not(rcc_f37))]
+    let adc = match config.adc {
         AdcClockSource::Pll(adcpres) => {
-            RCC.cfgr2().modify(|w| {
-                // Make sure that we're using the PLL
-                pll_config.unwrap();
-                w.set_adc12pres(adcpres);
+            RCC.cfgr2().modify(|w| w.set_adc12pres(adcpres));
+            crate::pac::ADC_COMMON
+                .ccr()
+                .modify(|w| w.set_ckmode(Ckmode::ASYNCHRONOUS));
 
-                sysclk / adcpres
-            })
+            unwrap!(pll) / adcpres
         }
-        _ => crate::pac::ADC_COMMON.ccr().modify(|w| {
-            assert!(!(adc.bus_div() == 1 && hpre != Hpre::DIV1));
+        AdcClockSource::Hclk(adcpres) => {
+            assert!(!(adcpres == AdcHclkPrescaler::Div1 && config.ahb_pre != AHBPrescaler::DIV1));
 
-            w.set_ckmode(adc.into());
+            let (div, ckmode) = match adcpres {
+                AdcHclkPrescaler::Div1 => (1u32, Ckmode::SYNCDIV1),
+                AdcHclkPrescaler::Div2 => (2u32, Ckmode::SYNCDIV2),
+                AdcHclkPrescaler::Div4 => (4u32, Ckmode::SYNCDIV4),
+            };
+            crate::pac::ADC_COMMON.ccr().modify(|w| w.set_ckmode(ckmode));
 
-            sysclk / adc.bus_div()
-        }),
-    });
+            hclk / div
+        }
+    };
 
-    #[cfg(all(rcc_f3, adc3_common))]
-    let adc34 = config.adc34.map(|adc| match adc {
+    #[cfg(all(not(rcc_f37), adc3_common))]
+    let adc34 = match config.adc34 {
         AdcClockSource::Pll(adcpres) => {
-            RCC.cfgr2().modify(|w| {
-                // Make sure that we're using the PLL
-                pll_config.unwrap();
-                w.set_adc34pres(adcpres);
+            RCC.cfgr2().modify(|w| w.set_adc34pres(adcpres));
+            crate::pac::ADC3_COMMON
+                .ccr()
+                .modify(|w| w.set_ckmode(Ckmode::ASYNCHRONOUS));
 
-                sysclk / adcpres
-            })
+            unwrap!(pll) / adcpres
         }
-        _ => crate::pac::ADC_COMMON.ccr().modify(|w| {
-            assert!(!(adc.bus_div() == 1 && hpre != Hpre::DIV1));
+        AdcClockSource::Hclk(adcpres) => {
+            assert!(!(adcpres == AdcHclkPrescaler::Div1 && config.ahb_pre != AHBPrescaler::DIV1));
 
-            w.set_ckmode(adc.into());
+            let (div, ckmode) = match adcpres {
+                AdcHclkPrescaler::Div1 => (1u32, Ckmode::SYNCDIV1),
+                AdcHclkPrescaler::Div2 => (2u32, Ckmode::SYNCDIV2),
+                AdcHclkPrescaler::Div4 => (4u32, Ckmode::SYNCDIV4),
+            };
+            crate::pac::ADC3_COMMON.ccr().modify(|w| w.set_ckmode(ckmode));
 
-            sysclk / adc.bus_div()
-        }),
-    });
+            hclk / div
+        }
+    };
 
     #[cfg(stm32f334)]
     let hrtim = match config.hrtim {
@@ -267,195 +296,49 @@ pub(crate) unsafe fn init(config: Config) {
             use crate::pac::rcc::vals::Timsw;
 
             // Make sure that we're using the PLL
-            pll_config.unwrap();
-            assert!((pclk2 == sysclk) || (pclk2 * 2u32 == sysclk));
+            let pll = unwrap!(pll);
+            assert!((pclk2 == pll) || (pclk2 * 2u32 == pll));
 
             RCC.cfgr3().modify(|w| w.set_hrtim1sw(Timsw::PLL1_P));
 
-            Some(sysclk * 2u32)
+            Some(pll * 2u32)
         }
     };
 
-    let rtc = config.ls.init();
-
     set_clocks!(
-        hsi: None,
-        lse: None,
-        pll1_p: None,
-        sys: Some(sysclk),
+        hsi: hsi,
+        hse: hse,
+        pll1_p: pll,
+        sys: Some(sys),
         pclk1: Some(pclk1),
         pclk2: Some(pclk2),
-        pclk1_tim: Some(pclk1 * timer_mul1),
-        pclk2_tim: Some(pclk2 * timer_mul2),
+        pclk1_tim: Some(pclk1_tim),
+        pclk2_tim: Some(pclk2_tim),
         hclk1: Some(hclk),
-        #[cfg(rcc_f3)]
-        adc: adc,
-        #[cfg(all(rcc_f3, adc3_common))]
-        adc34: adc34,
-        #[cfg(all(rcc_f3, not(adc3_common)))]
-        adc34: None,
+        #[cfg(not(rcc_f37))]
+        adc: Some(adc),
+        #[cfg(all(not(rcc_f37), adc3_common))]
+        adc34: Some(adc34),
         #[cfg(stm32f334)]
         hrtim: hrtim,
         rtc: rtc,
+        usb: usb,
+        lse: None,
     );
 }
 
-#[inline]
-fn get_sysclk(config: &Config) -> (Hertz, Option<PllConfig>) {
-    match (config.sysclk, config.hse) {
-        (Some(sysclk), Some(hse)) if sysclk == hse => (hse, None),
-        (Some(sysclk), None) if sysclk == HSI_FREQ => (HSI_FREQ, None),
-        // If the user selected System clock is different from HSI or HSE
-        // we will have to setup PLL clock source
-        (Some(sysclk), _) => {
-            let (sysclk, pll_config) = calc_pll(config, sysclk);
-            (sysclk, Some(pll_config))
-        }
-        (None, Some(hse)) => (hse, None),
-        (None, None) => (HSI_FREQ, None),
-    }
-}
+mod max {
+    use core::ops::RangeInclusive;
 
-#[inline]
-fn calc_pll(config: &Config, Hertz(sysclk): Hertz) -> (Hertz, PllConfig) {
-    // Calculates the Multiplier and the Divisor to arrive at
-    // the required System clock from PLL source frequency
-    let get_mul_div = |sysclk, pllsrcclk| {
-        let bus_div = gcd(sysclk, pllsrcclk);
-        let mut multiplier = sysclk / bus_div;
-        let mut divisor = pllsrcclk / bus_div;
-        // Minimum PLL multiplier is two
-        if multiplier == 1 {
-            multiplier *= 2;
-            divisor *= 2;
-        }
-        assert!(multiplier <= 16);
-        assert!(divisor <= 16);
-        (multiplier, divisor)
-    };
-    // Based on the source of Pll, we calculate the actual system clock
-    // frequency, PLL's source identifier, multiplier and divisor
-    let (act_sysclk, pll_src, pll_mul, pll_div) = match config.hse {
-        Some(Hertz(hse)) => {
-            let (multiplier, divisor) = get_mul_div(sysclk, hse);
-            (
-                Hertz((hse / divisor) * multiplier),
-                Pllsrc::HSE_DIV_PREDIV,
-                into_pll_mul(multiplier),
-                Some(into_pre_div(divisor)),
-            )
-        }
-        None => {
-            cfg_if::cfg_if! {
-                // For some chips PREDIV is always two, and cannot be changed
-                if #[cfg(any(flashsize_d, flashsize_e))] {
-                    let (multiplier, divisor) = get_mul_div(sysclk, HSI_FREQ.0);
-                    (
-                        Hertz((HSI_FREQ.0 / divisor) * multiplier),
-                        Pllsrc::HSI_DIV_PREDIV,
-                        into_pll_mul(multiplier),
-                        Some(into_pre_div(divisor)),
-                    )
-                } else {
-                    let pllsrcclk = HSI_FREQ.0 / 2;
-                    let multiplier = sysclk / pllsrcclk;
-                    assert!(multiplier <= 16);
-                    (
-                        Hertz(pllsrcclk * multiplier),
-                        Pllsrc::HSI_DIV2,
-                        into_pll_mul(multiplier),
-                        None,
-                    )
-                }
-            }
-        }
-    };
-    (
-        act_sysclk,
-        PllConfig {
-            pll_src,
-            pll_mul,
-            pll_div,
-        },
-    )
-}
+    use crate::time::Hertz;
 
-#[inline]
-#[allow(unused_variables)]
-fn get_usb_pre(config: &Config, sysclk: Hertz, pclk1: Hertz, pll_config: &Option<PllConfig>) -> Usbpre {
-    cfg_if::cfg_if! {
-        // Some chips do not have USB
-        if #[cfg(any(stm32f301, stm32f318, stm32f334))] {
-            panic!("USB clock not supported by the chip");
-        } else {
-            let usb_ok = config.hse.is_some() && pll_config.is_some() && (pclk1 >= Hertz(10_000_000));
-            match (usb_ok, sysclk) {
-                (true, Hertz(72_000_000)) => Usbpre::DIV1_5,
-                (true, Hertz(48_000_000)) => Usbpre::DIV1,
-                _ => panic!(
-                    "USB clock is only valid if the PLL output frequency is either 48MHz or 72MHz"
-                ),
-            }
-        }
-    }
-}
-
-// This function assumes cases when multiplier is one and it
-// being greater than 16 is made impossible
-#[inline]
-fn into_pll_mul(multiplier: u32) -> Pllmul {
-    match multiplier {
-        2 => Pllmul::MUL2,
-        3 => Pllmul::MUL3,
-        4 => Pllmul::MUL4,
-        5 => Pllmul::MUL5,
-        6 => Pllmul::MUL6,
-        7 => Pllmul::MUL7,
-        8 => Pllmul::MUL8,
-        9 => Pllmul::MUL9,
-        10 => Pllmul::MUL10,
-        11 => Pllmul::MUL11,
-        12 => Pllmul::MUL12,
-        13 => Pllmul::MUL13,
-        14 => Pllmul::MUL14,
-        15 => Pllmul::MUL15,
-        16 => Pllmul::MUL16,
-        _ => unreachable!(),
-    }
-}
+    pub(crate) const HSE_OSC: RangeInclusive<Hertz> = Hertz(4_000_000)..=Hertz(32_000_000);
+    pub(crate) const HSE_BYP: RangeInclusive<Hertz> = Hertz(1_000_000)..=Hertz(32_000_000);
 
-// This function assumes the incoming divisor cannot be greater
-// than 16
-#[inline]
-fn into_pre_div(divisor: u32) -> Prediv {
-    match divisor {
-        1 => Prediv::DIV1,
-        2 => Prediv::DIV2,
-        3 => Prediv::DIV3,
-        4 => Prediv::DIV4,
-        5 => Prediv::DIV5,
-        6 => Prediv::DIV6,
-        7 => Prediv::DIV7,
-        8 => Prediv::DIV8,
-        9 => Prediv::DIV9,
-        10 => Prediv::DIV10,
-        11 => Prediv::DIV11,
-        12 => Prediv::DIV12,
-        13 => Prediv::DIV13,
-        14 => Prediv::DIV14,
-        15 => Prediv::DIV15,
-        16 => Prediv::DIV16,
-        _ => unreachable!(),
-    }
-}
+    pub(crate) const HCLK: RangeInclusive<Hertz> = Hertz(0)..=Hertz(72_000_000);
+    pub(crate) const PCLK1: RangeInclusive<Hertz> = Hertz(0)..=Hertz(36_000_000);
+    pub(crate) const PCLK2: RangeInclusive<Hertz> = Hertz(0)..=Hertz(72_000_000);
 
-// Determine GCD using Euclidean algorithm
-#[inline]
-fn gcd(mut a: u32, mut b: u32) -> u32 {
-    while b != 0 {
-        let r = a % b;
-        a = b;
-        b = r;
-    }
-    a
+    pub(crate) const PLL_IN: RangeInclusive<Hertz> = Hertz(1_000_000)..=Hertz(24_000_000);
+    pub(crate) const PLL_OUT: RangeInclusive<Hertz> = Hertz(16_000_000)..=Hertz(72_000_000);
 }
diff --git a/embassy-stm32/src/rcc/mco.rs b/embassy-stm32/src/rcc/mco.rs
index eaaf8071c..db0df9fac 100644
--- a/embassy-stm32/src/rcc/mco.rs
+++ b/embassy-stm32/src/rcc/mco.rs
@@ -4,7 +4,7 @@ use embassy_hal_internal::into_ref;
 
 use crate::gpio::sealed::AFType;
 use crate::gpio::Speed;
-#[cfg(not(stm32f1))]
+#[cfg(not(any(stm32f1, rcc_f3v1, rcc_f37)))]
 pub use crate::pac::rcc::vals::Mcopre as McoPrescaler;
 #[cfg(not(any(rcc_f2, rcc_f410, rcc_f4, rcc_f7, rcc_h50, rcc_h5, rcc_h7ab, rcc_h7rm0433, rcc_h7)))]
 pub use crate::pac::rcc::vals::Mcosel as McoSource;
@@ -13,10 +13,16 @@ pub use crate::pac::rcc::vals::{Mco1sel as Mco1Source, Mco2sel as Mco2Source};
 use crate::pac::RCC;
 use crate::{peripherals, Peripheral};
 
+#[cfg(any(stm32f1, rcc_f3v1, rcc_f37))]
+#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd)]
+pub enum McoPrescaler {
+    DIV1,
+}
+
 pub(crate) mod sealed {
     pub trait McoInstance {
         type Source;
-        unsafe fn apply_clock_settings(source: Self::Source, #[cfg(not(stm32f1))] prescaler: super::McoPrescaler);
+        unsafe fn apply_clock_settings(source: Self::Source, prescaler: super::McoPrescaler);
     }
 }
 
@@ -29,7 +35,7 @@ macro_rules! impl_peri {
         impl sealed::McoInstance for peripherals::$peri {
             type Source = $source;
 
-            unsafe fn apply_clock_settings(source: Self::Source, #[cfg(not(stm32f1))] prescaler: McoPrescaler) {
+            unsafe fn apply_clock_settings(source: Self::Source, _prescaler: McoPrescaler) {
                 #[cfg(not(any(stm32u5, stm32wba)))]
                 let r = RCC.cfgr();
                 #[cfg(any(stm32u5, stm32wba))]
@@ -37,8 +43,8 @@ macro_rules! impl_peri {
 
                 r.modify(|w| {
                     w.$set_source(source);
-                    #[cfg(not(stm32f1))]
-                    w.$set_prescaler(prescaler);
+                    #[cfg(not(any(stm32f1, rcc_f3v1, rcc_f37)))]
+                    w.$set_prescaler(_prescaler);
                 });
             }
         }
@@ -68,16 +74,12 @@ impl<'d, T: McoInstance> Mco<'d, T> {
         _peri: impl Peripheral<P = T> + 'd,
         pin: impl Peripheral<P = impl McoPin<T>> + 'd,
         source: T::Source,
-        #[cfg(not(stm32f1))] prescaler: McoPrescaler,
+        prescaler: McoPrescaler,
     ) -> Self {
         into_ref!(pin);
 
         critical_section::with(|_| unsafe {
-            T::apply_clock_settings(
-                source,
-                #[cfg(not(stm32f1))]
-                prescaler,
-            );
+            T::apply_clock_settings(source, prescaler);
             pin.set_as_af(pin.af_num(), AFType::OutputPushPull);
             pin.set_speed(Speed::VeryHigh);
         });
diff --git a/examples/stm32f3/src/bin/hello.rs b/examples/stm32f3/src/bin/hello.rs
index fd54da53d..3c295612c 100644
--- a/examples/stm32f3/src/bin/hello.rs
+++ b/examples/stm32f3/src/bin/hello.rs
@@ -3,16 +3,13 @@
 
 use defmt::info;
 use embassy_executor::Spawner;
-use embassy_stm32::time::Hertz;
 use embassy_stm32::Config;
 use embassy_time::Timer;
 use {defmt_rtt as _, panic_probe as _};
 
 #[embassy_executor::main]
 async fn main(_spawner: Spawner) -> ! {
-    let mut config = Config::default();
-    config.rcc.hse = Some(Hertz(8_000_000));
-    config.rcc.sysclk = Some(Hertz(16_000_000));
+    let config = Config::default();
     let _p = embassy_stm32::init(config);
 
     loop {
diff --git a/examples/stm32f3/src/bin/usb_serial.rs b/examples/stm32f3/src/bin/usb_serial.rs
index cf9ecedfa..ee1c43afd 100644
--- a/examples/stm32f3/src/bin/usb_serial.rs
+++ b/examples/stm32f3/src/bin/usb_serial.rs
@@ -21,11 +21,22 @@ bind_interrupts!(struct Irqs {
 #[embassy_executor::main]
 async fn main(_spawner: Spawner) {
     let mut config = Config::default();
-    config.rcc.hse = Some(mhz(8));
-    config.rcc.sysclk = Some(mhz(48));
-    config.rcc.pclk1 = Some(mhz(24));
-    config.rcc.pclk2 = Some(mhz(24));
-    config.rcc.pll48 = true;
+    {
+        use embassy_stm32::rcc::*;
+        config.rcc.hse = Some(Hse {
+            freq: mhz(8),
+            mode: HseMode::Bypass,
+        });
+        config.rcc.pll = Some(Pll {
+            src: PllSource::HSE,
+            prediv: PllPreDiv::DIV1,
+            mul: PllMul::MUL9,
+        });
+        config.rcc.sys = Sysclk::PLL1_P;
+        config.rcc.ahb_pre = AHBPrescaler::DIV1;
+        config.rcc.apb1_pre = APBPrescaler::DIV2;
+        config.rcc.apb2_pre = APBPrescaler::DIV1;
+    }
     let p = embassy_stm32::init(config);
 
     info!("Hello World!");
diff --git a/examples/stm32f334/src/bin/adc.rs b/examples/stm32f334/src/bin/adc.rs
index 063ee9dac..a9fb7f1a6 100644
--- a/examples/stm32f334/src/bin/adc.rs
+++ b/examples/stm32f334/src/bin/adc.rs
@@ -5,7 +5,6 @@ use defmt::info;
 use embassy_executor::Spawner;
 use embassy_stm32::adc::{Adc, SampleTime};
 use embassy_stm32::peripherals::ADC1;
-use embassy_stm32::rcc::{AdcClockSource, Adcpres};
 use embassy_stm32::time::mhz;
 use embassy_stm32::{adc, bind_interrupts, Config};
 use embassy_time::{Delay, Timer};
@@ -18,12 +17,23 @@ bind_interrupts!(struct Irqs {
 #[embassy_executor::main]
 async fn main(_spawner: Spawner) -> ! {
     let mut config = Config::default();
-    config.rcc.sysclk = Some(mhz(64));
-    config.rcc.hclk = Some(mhz(64));
-    config.rcc.pclk1 = Some(mhz(32));
-    config.rcc.pclk2 = Some(mhz(64));
-    config.rcc.adc = Some(AdcClockSource::Pll(Adcpres::DIV1));
-
+    {
+        use embassy_stm32::rcc::*;
+        config.rcc.hse = Some(Hse {
+            freq: mhz(8),
+            mode: HseMode::Bypass,
+        });
+        config.rcc.pll = Some(Pll {
+            src: PllSource::HSE,
+            prediv: PllPreDiv::DIV1,
+            mul: PllMul::MUL9,
+        });
+        config.rcc.sys = Sysclk::PLL1_P;
+        config.rcc.ahb_pre = AHBPrescaler::DIV1;
+        config.rcc.apb1_pre = APBPrescaler::DIV2;
+        config.rcc.apb2_pre = APBPrescaler::DIV1;
+        config.rcc.adc = AdcClockSource::Pll(AdcPllPrescaler::DIV1);
+    }
     let mut p = embassy_stm32::init(config);
 
     info!("create adc...");
diff --git a/examples/stm32f334/src/bin/hello.rs b/examples/stm32f334/src/bin/hello.rs
index fd54da53d..3c295612c 100644
--- a/examples/stm32f334/src/bin/hello.rs
+++ b/examples/stm32f334/src/bin/hello.rs
@@ -3,16 +3,13 @@
 
 use defmt::info;
 use embassy_executor::Spawner;
-use embassy_stm32::time::Hertz;
 use embassy_stm32::Config;
 use embassy_time::Timer;
 use {defmt_rtt as _, panic_probe as _};
 
 #[embassy_executor::main]
 async fn main(_spawner: Spawner) -> ! {
-    let mut config = Config::default();
-    config.rcc.hse = Some(Hertz(8_000_000));
-    config.rcc.sysclk = Some(Hertz(16_000_000));
+    let config = Config::default();
     let _p = embassy_stm32::init(config);
 
     loop {
diff --git a/examples/stm32f334/src/bin/opamp.rs b/examples/stm32f334/src/bin/opamp.rs
index 850a0e335..6f25191be 100644
--- a/examples/stm32f334/src/bin/opamp.rs
+++ b/examples/stm32f334/src/bin/opamp.rs
@@ -6,7 +6,6 @@ use embassy_executor::Spawner;
 use embassy_stm32::adc::{Adc, SampleTime};
 use embassy_stm32::opamp::{OpAmp, OpAmpGain};
 use embassy_stm32::peripherals::ADC2;
-use embassy_stm32::rcc::{AdcClockSource, Adcpres};
 use embassy_stm32::time::mhz;
 use embassy_stm32::{adc, bind_interrupts, Config};
 use embassy_time::{Delay, Timer};
@@ -19,12 +18,23 @@ bind_interrupts!(struct Irqs {
 #[embassy_executor::main]
 async fn main(_spawner: Spawner) -> ! {
     let mut config = Config::default();
-    config.rcc.sysclk = Some(mhz(64));
-    config.rcc.hclk = Some(mhz(64));
-    config.rcc.pclk1 = Some(mhz(32));
-    config.rcc.pclk2 = Some(mhz(64));
-    config.rcc.adc = Some(AdcClockSource::Pll(Adcpres::DIV1));
-
+    {
+        use embassy_stm32::rcc::*;
+        config.rcc.hse = Some(Hse {
+            freq: mhz(8),
+            mode: HseMode::Bypass,
+        });
+        config.rcc.pll = Some(Pll {
+            src: PllSource::HSE,
+            prediv: PllPreDiv::DIV1,
+            mul: PllMul::MUL9,
+        });
+        config.rcc.sys = Sysclk::PLL1_P;
+        config.rcc.ahb_pre = AHBPrescaler::DIV1;
+        config.rcc.apb1_pre = APBPrescaler::DIV2;
+        config.rcc.apb2_pre = APBPrescaler::DIV1;
+        config.rcc.adc = AdcClockSource::Pll(AdcPllPrescaler::DIV1);
+    }
     let mut p = embassy_stm32::init(config);
 
     info!("create adc...");
diff --git a/examples/stm32f334/src/bin/pwm.rs b/examples/stm32f334/src/bin/pwm.rs
index c149cad92..7fc1ea926 100644
--- a/examples/stm32f334/src/bin/pwm.rs
+++ b/examples/stm32f334/src/bin/pwm.rs
@@ -4,7 +4,6 @@
 use defmt::*;
 use embassy_executor::Spawner;
 use embassy_stm32::hrtim::*;
-use embassy_stm32::rcc::HrtimClockSource;
 use embassy_stm32::time::{khz, mhz};
 use embassy_stm32::Config;
 use embassy_time::Timer;
@@ -12,14 +11,26 @@ use {defmt_rtt as _, panic_probe as _};
 
 #[embassy_executor::main]
 async fn main(_spawner: Spawner) {
-    let mut config: Config = Default::default();
-    config.rcc.sysclk = Some(mhz(64));
-    config.rcc.hclk = Some(mhz(64));
-    config.rcc.pclk1 = Some(mhz(32));
-    config.rcc.pclk2 = Some(mhz(64));
-    config.rcc.hrtim = HrtimClockSource::PllClk;
-
+    let mut config = Config::default();
+    {
+        use embassy_stm32::rcc::*;
+        config.rcc.hse = Some(Hse {
+            freq: mhz(8),
+            mode: HseMode::Bypass,
+        });
+        config.rcc.pll = Some(Pll {
+            src: PllSource::HSE,
+            prediv: PllPreDiv::DIV1,
+            mul: PllMul::MUL9,
+        });
+        config.rcc.sys = Sysclk::PLL1_P;
+        config.rcc.ahb_pre = AHBPrescaler::DIV1;
+        config.rcc.apb1_pre = APBPrescaler::DIV2;
+        config.rcc.apb2_pre = APBPrescaler::DIV1;
+        config.rcc.hrtim = HrtimClockSource::PllClk;
+    }
     let p = embassy_stm32::init(config);
+
     info!("Hello World!");
 
     let ch1 = PwmPin::new_cha(p.PA8);
diff --git a/tests/stm32/src/common.rs b/tests/stm32/src/common.rs
index fefe72c86..36fe8a235 100644
--- a/tests/stm32/src/common.rs
+++ b/tests/stm32/src/common.rs
@@ -276,6 +276,24 @@ pub fn config() -> Config {
         config.rcc.apb2_pre = APBPrescaler::DIV2;
     }
 
+    #[cfg(feature = "stm32f303ze")]
+    {
+        use embassy_stm32::rcc::*;
+        config.rcc.hse = Some(Hse {
+            freq: Hertz(8_000_000),
+            mode: HseMode::Bypass,
+        });
+        config.rcc.pll = Some(Pll {
+            src: PllSource::HSE,
+            prediv: PllPreDiv::DIV1,
+            mul: PllMul::MUL9,
+        });
+        config.rcc.sys = Sysclk::PLL1_P;
+        config.rcc.ahb_pre = AHBPrescaler::DIV1;
+        config.rcc.apb1_pre = APBPrescaler::DIV2;
+        config.rcc.apb2_pre = APBPrescaler::DIV1;
+    }
+
     #[cfg(feature = "stm32f429zi")]
     {
         use embassy_stm32::rcc::*;