stm32/rcc: port L4 to the "flattened" API like h5/h7.

embassy-stm32/src/rcc/l4.rs

@@ -1,9 +1,8 @@
 use crate::pac::rcc::regs::Cfgr;
 pub use crate::pac::rcc::vals::{
     Hpre as AHBPrescaler, Msirange as MSIRange, Pllm as PllPreDiv, Plln as PllMul, Pllp as PllPDiv, Pllq as PllQDiv,
-    Pllr as PllRDiv, Ppre as APBPrescaler,
+    Pllr as PllRDiv, Pllsrc as PLLSource, Ppre as APBPrescaler, Sw as ClockSrc,
 };
-use crate::pac::rcc::vals::{Msirange, Pllsrc, Sw};
 use crate::pac::{FLASH, RCC};
 use crate::rcc::{set_freqs, Clocks};
 use crate::time::Hertz;
@@ -11,42 +10,47 @@ use crate::time::Hertz;
 /// HSI speed
 pub const HSI_FREQ: Hertz = Hertz(16_000_000);
 
-/// System clock mux source
 #[derive(Clone, Copy)]
-pub enum ClockSrc {
+pub struct Pll {
-    MSI(MSIRange),
+    /// PLL pre-divider (DIVM).
-    PLL(PLLSource, PllRDiv, PllPreDiv, PllMul, Option<PllQDiv>),
+    pub prediv: PllPreDiv,
-    HSE(Hertz),
-    HSI16,
-}
 
-/// PLL clock input source
+    /// PLL multiplication factor.
-#[derive(Clone, Copy)]
+    pub mul: PllMul,
-pub enum PLLSource {
-    HSI16,
-    HSE(Hertz),
-    MSI(MSIRange),
-}
 
-impl From<PLLSource> for Pllsrc {
+    /// PLL P division factor. If None, PLL P output is disabled.
-    fn from(val: PLLSource) -> Pllsrc {
+    pub divp: Option<PllPDiv>,
-        match val {
+    /// PLL Q division factor. If None, PLL Q output is disabled.
-            PLLSource::HSI16 => Pllsrc::HSI16,
+    pub divq: Option<PllQDiv>,
-            PLLSource::HSE(_) => Pllsrc::HSE,
+    /// PLL R division factor. If None, PLL R output is disabled.
-            PLLSource::MSI(_) => Pllsrc::MSI,
+    pub divr: Option<PllRDiv>,
-        }
-    }
 }
 
 /// Clocks configutation
 pub struct Config {
+    // base clock sources
+    pub msi: Option<MSIRange>,
+    pub hsi16: bool,
+    pub hse: Option<Hertz>,
+    #[cfg(not(any(stm32l471, stm32l475, stm32l476, stm32l486)))]
+    pub hsi48: bool,
+
+    // pll
+    pub pll_src: PLLSource,
+    pub pll: Option<Pll>,
+    pub pllsai1: Option<Pll>,
+    #[cfg(any(
+        stm32l47x, stm32l48x, stm32l49x, stm32l4ax, stm32l4px, stm32l4qx, stm32l4rx, stm32l4sx
+    ))]
+    pub pllsai2: Option<Pll>,
+
+    // sysclk, buses.
     pub mux: ClockSrc,
     pub ahb_pre: AHBPrescaler,
     pub apb1_pre: APBPrescaler,
     pub apb2_pre: APBPrescaler,
-    pub pllsai1: Option<(PllMul, PllPreDiv, Option<PllRDiv>, Option<PllQDiv>, Option<PllPDiv>)>,
+
-    #[cfg(not(any(stm32l471, stm32l475, stm32l476, stm32l486)))]
+    // low speed LSI/LSE/RTC
-    pub hsi48: bool,
     pub ls: super::LsConfig,
 }
 
@@ -54,11 +58,20 @@ impl Default for Config {
     #[inline]
     fn default() -> Config {
         Config {
-            mux: ClockSrc::MSI(MSIRange::RANGE4M),
+            hse: None,
+            hsi16: false,
+            msi: Some(MSIRange::RANGE4M),
+            mux: ClockSrc::MSI,
             ahb_pre: AHBPrescaler::DIV1,
             apb1_pre: APBPrescaler::DIV1,
             apb2_pre: APBPrescaler::DIV1,
+            pll_src: PLLSource::NONE,
+            pll: None,
             pllsai1: None,
+            #[cfg(any(
+                stm32l47x, stm32l48x, stm32l49x, stm32l4ax, stm32l4px, stm32l4qx, stm32l4rx, stm32l4sx
+            ))]
+            pllsai2: None,
             #[cfg(not(any(stm32l471, stm32l475, stm32l476, stm32l486)))]
             hsi48: false,
             ls: Default::default(),
@@ -80,154 +93,204 @@ pub(crate) unsafe fn init(config: Config) {
         // Wait until MSI is running
         while !RCC.cr().read().msirdy() {}
     }
-    if RCC.cfgr().read().sws() != Sw::MSI {
+    if RCC.cfgr().read().sws() != ClockSrc::MSI {
         // Set MSI as a clock source, reset prescalers.
         RCC.cfgr().write_value(Cfgr::default());
         // Wait for clock switch status bits to change.
-        while RCC.cfgr().read().sws() != Sw::MSI {}
+        while RCC.cfgr().read().sws() != ClockSrc::MSI {}
     }
 
     let rtc = config.ls.init();
 
-    let (sys_clk, sw) = match config.mux {
+    let msi = config.msi.map(|range| {
-        ClockSrc::MSI(range) => {
+        // Enable MSI
-            // Enable MSI
+        RCC.cr().write(|w| {
-            RCC.cr().write(|w| {
+            w.set_msirange(range);
-                w.set_msirange(range);
+            w.set_msirgsel(true);
-                w.set_msirgsel(true);
+            w.set_msion(true);
-                w.set_msion(true);
 
-                // If LSE is enabled, enable calibration of MSI
+            // If LSE is enabled, enable calibration of MSI
-                w.set_msipllen(config.ls.lse.is_some());
+            w.set_msipllen(config.ls.lse.is_some());
-            });
+        });
-            while !RCC.cr().read().msirdy() {}
+        while !RCC.cr().read().msirdy() {}
 
-            // Enable as clock source for USB, RNG if running at 48 MHz
+        // Enable as clock source for USB, RNG if running at 48 MHz
-            if range == MSIRange::RANGE48M {
+        if range == MSIRange::RANGE48M {
-                RCC.ccipr().modify(|w| {
+            RCC.ccipr().modify(|w| w.set_clk48sel(0b11));
-                    w.set_clk48sel(0b11);
-                });
-            }
-            (msirange_to_hertz(range), Sw::MSI)
         }
-        ClockSrc::HSI16 => {
-            // Enable HSI16
-            RCC.cr().write(|w| w.set_hsion(true));
-            while !RCC.cr().read().hsirdy() {}
 
-            (HSI_FREQ, Sw::HSI16)
+        msirange_to_hertz(range)
-        }
+    });
-        ClockSrc::HSE(freq) => {
-            // Enable HSE
-            RCC.cr().write(|w| w.set_hseon(true));
-            while !RCC.cr().read().hserdy() {}
 
-            (freq, Sw::HSE)
+    let hsi16 = config.hsi16.then(|| {
-        }
+        RCC.cr().write(|w| w.set_hsion(true));
-        ClockSrc::PLL(src, divr, prediv, mul, divq) => {
+        while !RCC.cr().read().hsirdy() {}
-            let src_freq = match src {
-                PLLSource::HSE(freq) => {
-                    // Enable HSE
-                    RCC.cr().write(|w| w.set_hseon(true));
-                    while !RCC.cr().read().hserdy() {}
-                    freq
-                }
-                PLLSource::HSI16 => {
-                    // Enable HSI
-                    RCC.cr().write(|w| w.set_hsion(true));
-                    while !RCC.cr().read().hsirdy() {}
-                    HSI_FREQ
-                }
-                PLLSource::MSI(range) => {
-                    // Enable MSI
-                    RCC.cr().write(|w| {
-                        w.set_msirange(range);
-                        w.set_msipllen(false); // should be turned on if LSE is started
-                        w.set_msirgsel(true);
-                        w.set_msion(true);
-                    });
-                    while !RCC.cr().read().msirdy() {}
 
-                    msirange_to_hertz(range)
+        HSI_FREQ
-                }
+    });
-            };
 
-            // Disable PLL
+    let hse = config.hse.map(|freq| {
-            RCC.cr().modify(|w| w.set_pllon(false));
+        RCC.cr().write(|w| w.set_hseon(true));
-            while RCC.cr().read().pllrdy() {}
+        while !RCC.cr().read().hserdy() {}
 
-            let freq = src_freq / prediv * mul / divr;
+        freq
-
+    });
-            #[cfg(any(stm32l4px, stm32l4qx, stm32l4rx, stm32l4sx))]
-            assert!(freq.0 <= 120_000_000);
-            #[cfg(not(any(stm32l4px, stm32l4qx, stm32l4rx, stm32l4sx)))]
-            assert!(freq.0 <= 80_000_000);
-
-            RCC.pllcfgr().write(move |w| {
-                w.set_plln(mul);
-                w.set_pllm(prediv);
-                w.set_pllr(divr);
-                if let Some(divq) = divq {
-                    w.set_pllq(divq);
-                    w.set_pllqen(true);
-                }
-                w.set_pllsrc(src.into());
-            });
-
-            // Enable as clock source for USB, RNG if PLL48 divisor is provided
-            if let Some(divq) = divq {
-                let freq = src_freq / prediv * mul / divq;
-                assert!(freq.0 == 48_000_000);
-                RCC.ccipr().modify(|w| {
-                    w.set_clk48sel(0b10);
-                });
-            }
-
-            if let Some((mul, prediv, r_div, q_div, p_div)) = config.pllsai1 {
-                RCC.pllsai1cfgr().write(move |w| {
-                    w.set_plln(mul);
-                    w.set_pllm(prediv);
-                    if let Some(r_div) = r_div {
-                        w.set_pllr(r_div);
-                        w.set_pllren(true);
-                    }
-                    if let Some(q_div) = q_div {
-                        w.set_pllq(q_div);
-                        w.set_pllqen(true);
-                        let freq = src_freq / prediv * mul / q_div;
-                        if freq.0 == 48_000_000 {
-                            RCC.ccipr().modify(|w| {
-                                w.set_clk48sel(0b1);
-                            });
-                        }
-                    }
-                    if let Some(p_div) = p_div {
-                        w.set_pllp(p_div);
-                        w.set_pllpen(true);
-                    }
-                });
-
-                RCC.cr().modify(|w| w.set_pllsai1on(true));
-            }
-
-            // Enable PLL
-            RCC.cr().modify(|w| w.set_pllon(true));
-            while !RCC.cr().read().pllrdy() {}
-            RCC.pllcfgr().modify(|w| w.set_pllren(true));
-
-            (freq, Sw::PLL)
-        }
-    };
 
     #[cfg(not(any(stm32l471, stm32l475, stm32l476, stm32l486)))]
-    if config.hsi48 {
+    let _hsi48 = config.hsi48.then(|| {
         RCC.crrcr().modify(|w| w.set_hsi48on(true));
         while !RCC.crrcr().read().hsi48rdy() {}
 
         // Enable as clock source for USB, RNG and SDMMC
         RCC.ccipr().modify(|w| w.set_clk48sel(0));
+
+        Hertz(48_000_000)
+    });
+
+    let pll_src = match config.pll_src {
+        PLLSource::NONE => None,
+        PLLSource::HSE => hse,
+        PLLSource::HSI16 => hsi16,
+        PLLSource::MSI => msi,
+    };
+
+    let mut _pllp = None;
+    let mut _pllq = None;
+    let mut _pllr = None;
+    if let Some(pll) = config.pll {
+        let pll_src = pll_src.unwrap();
+
+        // Disable PLL
+        RCC.cr().modify(|w| w.set_pllon(false));
+        while RCC.cr().read().pllrdy() {}
+
+        let vco_freq = pll_src / pll.prediv * pll.mul;
+
+        _pllp = pll.divp.map(|div| vco_freq / div);
+        _pllq = pll.divq.map(|div| vco_freq / div);
+        _pllr = pll.divr.map(|div| vco_freq / div);
+
+        RCC.pllcfgr().write(move |w| {
+            w.set_plln(pll.mul);
+            w.set_pllm(pll.prediv);
+            w.set_pllsrc(config.pll_src);
+            if let Some(divp) = pll.divp {
+                w.set_pllp(divp);
+                w.set_pllpen(true);
+            }
+            if let Some(divq) = pll.divq {
+                w.set_pllq(divq);
+                w.set_pllqen(true);
+            }
+            if let Some(divr) = pll.divr {
+                w.set_pllr(divr);
+                w.set_pllren(true);
+            }
+        });
+
+        if _pllq == Some(Hertz(48_000_000)) {
+            RCC.ccipr().modify(|w| w.set_clk48sel(0b10));
+        }
+
+        // Enable PLL
+        RCC.cr().modify(|w| w.set_pllon(true));
+        while !RCC.cr().read().pllrdy() {}
+    } else {
+        // even if we're not using the main pll, set the source for pllsai
+        RCC.pllcfgr().write(move |w| {
+            w.set_pllsrc(config.pll_src);
+        });
     }
 
+    if let Some(pll) = config.pllsai1 {
+        let pll_src = pll_src.unwrap();
+
+        // Disable PLL
+        RCC.cr().modify(|w| w.set_pllsai1on(false));
+        while RCC.cr().read().pllsai1rdy() {}
+
+        let vco_freq = pll_src / pll.prediv * pll.mul;
+
+        let _pllp = pll.divp.map(|div| vco_freq / div);
+        let _pllq = pll.divq.map(|div| vco_freq / div);
+        let _pllr = pll.divr.map(|div| vco_freq / div);
+
+        RCC.pllsai1cfgr().write(move |w| {
+            w.set_plln(pll.mul);
+            w.set_pllm(pll.prediv);
+            if let Some(divp) = pll.divp {
+                w.set_pllp(divp);
+                w.set_pllpen(true);
+            }
+            if let Some(divq) = pll.divq {
+                w.set_pllq(divq);
+                w.set_pllqen(true);
+            }
+            if let Some(divr) = pll.divr {
+                w.set_pllr(divr);
+                w.set_pllren(true);
+            }
+        });
+
+        if _pllq == Some(Hertz(48_000_000)) {
+            RCC.ccipr().modify(|w| w.set_clk48sel(0b01));
+        }
+
+        // Enable PLL
+        RCC.cr().modify(|w| w.set_pllsai1on(true));
+        while !RCC.cr().read().pllsai1rdy() {}
+    }
+
+    #[cfg(any(
+        stm32l47x, stm32l48x, stm32l49x, stm32l4ax, stm32l4px, stm32l4qx, stm32l4rx, stm32l4sx
+    ))]
+    if let Some(pll) = config.pllsai2 {
+        let pll_src = pll_src.unwrap();
+
+        // Disable PLL
+        RCC.cr().modify(|w| w.set_pllsai2on(false));
+        while RCC.cr().read().pllsai2rdy() {}
+
+        let vco_freq = pll_src / pll.prediv * pll.mul;
+
+        let _pllp = pll.divp.map(|div| vco_freq / div);
+        let _pllq = pll.divq.map(|div| vco_freq / div);
+        let _pllr = pll.divr.map(|div| vco_freq / div);
+
+        RCC.pllsai2cfgr().write(move |w| {
+            w.set_plln(pll.mul);
+            w.set_pllm(pll.prediv);
+            if let Some(divp) = pll.divp {
+                w.set_pllp(divp);
+                w.set_pllpen(true);
+            }
+            if let Some(divq) = pll.divq {
+                w.set_pllq(divq);
+                w.set_pllqen(true);
+            }
+            if let Some(divr) = pll.divr {
+                w.set_pllr(divr);
+                w.set_pllren(true);
+            }
+        });
+
+        // Enable PLL
+        RCC.cr().modify(|w| w.set_pllsai2on(true));
+        while !RCC.cr().read().pllsai2rdy() {}
+    }
+
+    let sys_clk = match config.mux {
+        ClockSrc::HSE => hse.unwrap(),
+        ClockSrc::HSI16 => hsi16.unwrap(),
+        ClockSrc::MSI => msi.unwrap(),
+        ClockSrc::PLL => _pllr.unwrap(),
+    };
+
+    #[cfg(any(stm32l4px, stm32l4qx, stm32l4rx, stm32l4sx))]
+    assert!(sys_clk.0 <= 120_000_000);
+    #[cfg(not(any(stm32l4px, stm32l4qx, stm32l4rx, stm32l4sx)))]
+    assert!(sys_clk.0 <= 80_000_000);
+
     // Set flash wait states
     FLASH.acr().modify(|w| {
         w.set_latency(match sys_clk.0 {
@@ -240,7 +303,7 @@ pub(crate) unsafe fn init(config: Config) {
     });
 
     RCC.cfgr().modify(|w| {
-        w.set_sw(sw);
+        w.set_sw(config.mux);
         w.set_hpre(config.ahb_pre);
         w.set_ppre1(config.apb1_pre);
         w.set_ppre2(config.apb2_pre);
@@ -277,7 +340,7 @@ pub(crate) unsafe fn init(config: Config) {
     });
 }
 
-fn msirange_to_hertz(range: Msirange) -> Hertz {
+fn msirange_to_hertz(range: MSIRange) -> Hertz {
     match range {
         MSIRange::RANGE100K => Hertz(100_000),
         MSIRange::RANGE200K => Hertz(200_000),

examples/stm32l4/src/bin/rng.rs

@@ -4,7 +4,7 @@
 
 use defmt::*;
 use embassy_executor::Spawner;
-use embassy_stm32::rcc::{ClockSrc, PLLSource, PllMul, PllPreDiv, PllQDiv, PllRDiv};
+use embassy_stm32::rcc::{ClockSrc, PLLSource, Pll, PllMul, PllPreDiv, PllQDiv, PllRDiv};
 use embassy_stm32::rng::Rng;
 use embassy_stm32::{bind_interrupts, peripherals, rng, Config};
 use {defmt_rtt as _, panic_probe as _};
@@ -16,14 +16,16 @@ bind_interrupts!(struct Irqs {
 #[embassy_executor::main]
 async fn main(_spawner: Spawner) {
     let mut config = Config::default();
-    // 72Mhz clock (16 / 1 * 18 / 4)
+    config.rcc.mux = ClockSrc::PLL;
-    config.rcc.mux = ClockSrc::PLL(
+    config.rcc.hsi16 = true;
-        PLLSource::HSI16,
+    config.rcc.pll_src = PLLSource::HSI16;
-        PllRDiv::DIV4,
+    config.rcc.pll = Some(Pll {
-        PllPreDiv::DIV1,
+        prediv: PllPreDiv::DIV1,
-        PllMul::MUL18,
+        mul: PllMul::MUL18,
-        Some(PllQDiv::DIV6), // 48Mhz (16 / 1 * 18 / 6)
+        divp: None,
-    );
+        divq: Some(PllQDiv::DIV6), // 48Mhz (16 / 1 * 18 / 6)
+        divr: Some(PllRDiv::DIV4), // sysclk 72Mhz clock (16 / 1 * 18 / 4)
+    });
     let p = embassy_stm32::init(config);
 
     info!("Hello World!");

examples/stm32l4/src/bin/rtc.rs

@@ -5,7 +5,7 @@
 use chrono::{NaiveDate, NaiveDateTime};
 use defmt::*;
 use embassy_executor::Spawner;
-use embassy_stm32::rcc::{ClockSrc, LsConfig, PLLSource, PllMul, PllPreDiv, PllRDiv};
+use embassy_stm32::rcc::{ClockSrc, LsConfig, PLLSource, Pll, PllMul, PllPreDiv, PllRDiv};
 use embassy_stm32::rtc::{Rtc, RtcConfig};
 use embassy_stm32::time::Hertz;
 use embassy_stm32::Config;
@@ -14,18 +14,20 @@ use {defmt_rtt as _, panic_probe as _};
 
 #[embassy_executor::main]
 async fn main(_spawner: Spawner) {
-    let p = {
+    let mut config = Config::default();
-        let mut config = Config::default();
+    config.rcc.mux = ClockSrc::PLL;
-        config.rcc.mux = ClockSrc::PLL(
+    config.rcc.hse = Some(Hertz::mhz(8));
-            PLLSource::HSE(Hertz::mhz(8)),
+    config.rcc.pll_src = PLLSource::HSE;
-            PllRDiv::DIV2,
+    config.rcc.pll = Some(Pll {
-            PllPreDiv::DIV1,
+        prediv: PllPreDiv::DIV1,
-            PllMul::MUL20,
+        mul: PllMul::MUL20,
-            None,
+        divp: None,
-        );
+        divq: None,
-        config.rcc.ls = LsConfig::default_lse();
+        divr: Some(PllRDiv::DIV2), // sysclk 80Mhz clock (8 / 1 * 20 / 2)
-        embassy_stm32::init(config)
+    });
-    };
+    config.rcc.ls = LsConfig::default_lse();
+    let p = embassy_stm32::init(config);
+
     info!("Hello World!");
 
     let now = NaiveDate::from_ymd_opt(2020, 5, 15)

examples/stm32l4/src/bin/spe_adin1110_http_server.rs

@@ -48,7 +48,7 @@ use embassy_net_adin1110::{self, Device, Runner, ADIN1110};
 use embedded_hal_bus::spi::ExclusiveDevice;
 use hal::gpio::Pull;
 use hal::i2c::Config as I2C_Config;
-use hal::rcc::{ClockSrc, PLLSource, PllMul, PllPreDiv, PllRDiv};
+use hal::rcc::{ClockSrc, PLLSource, Pll, PllMul, PllPreDiv, PllRDiv};
 use hal::spi::{Config as SPI_Config, Spi};
 use hal::time::Hertz;
 
@@ -77,13 +77,16 @@ async fn main(spawner: Spawner) {
 
     // 80Mhz clock (Source: 8 / SrcDiv: 1 * PLLMul 20 / ClkDiv 2)
     // 80MHz highest frequency for flash 0 wait.
-    config.rcc.mux = ClockSrc::PLL(
+    config.rcc.mux = ClockSrc::PLL;
-        PLLSource::HSE(Hertz(8_000_000)),
+    config.rcc.hse = Some(Hertz::mhz(8));
-        PllRDiv::DIV2,
+    config.rcc.pll_src = PLLSource::HSE;
-        PllPreDiv::DIV1,
+    config.rcc.pll = Some(Pll {
-        PllMul::MUL20,
+        prediv: PllPreDiv::DIV1,
-        None,
+        mul: PllMul::MUL20,
-    );
+        divp: None,
+        divq: None,
+        divr: Some(PllRDiv::DIV2), // sysclk 80Mhz clock (8 / 1 * 20 / 2)
+    });
     config.rcc.hsi48 = true; // needed for rng
 
     let dp = embassy_stm32::init(config);

examples/stm32l4/src/bin/usb_serial.rs

@@ -23,8 +23,17 @@ async fn main(_spawner: Spawner) {
     info!("Hello World!");
 
     let mut config = Config::default();
-    config.rcc.mux = ClockSrc::PLL(PLLSource::HSI16, PllRDiv::DIV2, PllPreDiv::DIV1, PllMul::MUL10, None);
     config.rcc.hsi48 = true;
+    config.rcc.mux = ClockSrc::PLL;
+    config.rcc.hsi16 = true;
+    config.rcc.pll_src = PLLSource::HSI16;
+    config.rcc.pll = Some(Pll {
+        prediv: PllPreDiv::DIV1,
+        mul: PllMul::MUL10,
+        divp: None,
+        divq: None,
+        divr: Some(PllRDiv::DIV2), // sysclk 80Mhz (16 / 1 * 10 / 2)
+    });
 
     let p = embassy_stm32::init(config);
 

tests/stm32/src/common.rs

@@ -284,17 +284,19 @@ pub fn config() -> Config {
         config.rcc.adc_clock_source = AdcClockSource::PLL2_P;
     }
 
-    #[cfg(any(feature = "stm32l4a6zg", feature = "stm32l4r5zi"))]
+    #[cfg(any(feature = "stm32l496zg", feature = "stm32l4a6zg", feature = "stm32l4r5zi"))]
     {
         use embassy_stm32::rcc::*;
-        config.rcc.mux = ClockSrc::PLL(
+        config.rcc.mux = ClockSrc::PLL;
-            // 72Mhz clock (16 / 1 * 18 / 4)
+        config.rcc.hsi16 = true;
-            PLLSource::HSI16,
+        config.rcc.pll_src = PLLSource::HSI16;
-            PllRDiv::DIV4,
+        config.rcc.pll = Some(Pll {
-            PllPreDiv::DIV1,
+            prediv: PllPreDiv::DIV1,
-            PllMul::MUL18,
+            mul: PllMul::MUL18,
-            Some(PllQDiv::DIV6), // 48Mhz (16 / 1 * 18 / 6)
+            divp: None,
-        );
+            divq: Some(PllQDiv::DIV6), // 48Mhz (16 / 1 * 18 / 6)
+            divr: Some(PllRDiv::DIV4), // sysclk 72Mhz clock (16 / 1 * 18 / 4)
+        });
     }
 
     #[cfg(any(feature = "stm32l552ze"))]