4 files changed, 80 insertions, 78 deletions

diff --git a/embassy-stm32/src/rcc/bd.rs b/embassy-stm32/src/rcc/bd.rs
index 4d8ed82aa..34b88458f 100644
--- a/embassy-stm32/src/rcc/bd.rs
+++ b/embassy-stm32/src/rcc/bd.rs
@@ -1,6 +1,34 @@
+#[allow(dead_code)]
+#[derive(Default)]
+pub enum LseDrive {
+    #[cfg(any(rtc_v2f7, rtc_v2l4))]
+    Low = 0,
+    MediumLow = 0x01,
+    #[default]
+    MediumHigh = 0x02,
+    #[cfg(any(rtc_v2f7, rtc_v2l4))]
+    High = 0x03,
+}
+
+#[cfg(any(rtc_v2f7, rtc_v2h7, rtc_v2l0, rtc_v2l4))]
+impl From<LseDrive> for crate::pac::rcc::vals::Lsedrv {
+    fn from(value: LseDrive) -> Self {
+        use crate::pac::rcc::vals::Lsedrv;
+
+        match value {
+            #[cfg(any(rtc_v2f7, rtc_v2l4))]
+            LseDrive::Low => Lsedrv::LOW,
+            LseDrive::MediumLow => Lsedrv::MEDIUMLOW,
+            LseDrive::MediumHigh => Lsedrv::MEDIUMHIGH,
+            #[cfg(any(rtc_v2f7, rtc_v2l4))]
+            LseDrive::High => Lsedrv::HIGH,
+        }
+    }
+}
+
+#[allow(dead_code)]
 #[derive(Copy, Clone, Debug, PartialEq)]
 #[repr(u8)]
-#[allow(dead_code)]
 pub enum RtcClockSource {
     /// 00: No clock
     NoClock = 0b00,
@@ -66,6 +94,38 @@ impl BackupDomain {
         r
     }
 
+    #[allow(dead_code, unused_variables)]
+    #[cfg(any(rtc_v2f4, rtc_v2f7, rtc_v2h7, rtc_v2l0, rtc_v2l1, rtc_v2l4, rtc_v2wb, rtc_v3))]
+    pub fn enable_lse(lse_drive: LseDrive) {
+        Self::modify(|w| {
+            #[cfg(any(rtc_v2f7, rtc_v2h7, rtc_v2l0, rtc_v2l4))]
+            w.set_lsedrv(lse_drive.into());
+            w.set_lseon(true);
+        });
+
+        while !Self::read().lserdy() {}
+    }
+
+    #[allow(dead_code)]
+    #[cfg(any(rtc_v2f4, rtc_v2f7, rtc_v2h7, rtc_v2l0, rtc_v2l1, rtc_v2l4, rtc_v2wb, rtc_v3))]
+    pub fn enable_lsi() {
+        let csr = crate::pac::RCC.csr();
+
+        Self::modify(|_| {
+            #[cfg(not(rtc_v2wb))]
+            csr.modify(|w| w.set_lsion(true));
+
+            #[cfg(rtc_v2wb)]
+            csr.modify(|w| w.set_lsi1on(true));
+        });
+
+        #[cfg(not(rtc_v2wb))]
+        while !csr.read().lsirdy() {}
+
+        #[cfg(rtc_v2wb)]
+        while !csr.read().lsi1rdy() {}
+    }
+
     #[cfg(any(
         rtc_v2f0, rtc_v2f2, rtc_v2f3, rtc_v2f4, rtc_v2f7, rtc_v2h7, rtc_v2l0, rtc_v2l1, rtc_v2l4, rtc_v2wb, rtc_v3,
         rtc_v3u5
@@ -74,7 +134,7 @@ impl BackupDomain {
     pub fn set_rtc_clock_source(clock_source: RtcClockSource) {
         let clock_source = clock_source as u8;
         #[cfg(any(
-            all(not(any(rtc_v3, rtc_v3u5)), not(rtc_v2wb)),
+            not(any(rtc_v3, rtc_v3u5, rtc_v2wb)),
             all(any(rtc_v3, rtc_v3u5), not(any(rcc_wl5, rcc_wle)))
         ))]
         let clock_source = crate::pac::rcc::vals::Rtcsel::from_bits(clock_source);
@@ -86,6 +146,18 @@ impl BackupDomain {
         });
     }
 
+    #[cfg(any(rtc_v2f4, rtc_v2f7, rtc_v2h7, rtc_v2l0, rtc_v2l1, rtc_v2l4, rtc_v2wb, rtc_v3))]
+    #[allow(dead_code, unused_variables)]
+    pub fn configure_rtc(clock_source: RtcClockSource, lse_drive: Option<LseDrive>) {
+        match clock_source {
+            RtcClockSource::LSI => Self::enable_lsi(),
+            RtcClockSource::LSE => Self::enable_lse(lse_drive.unwrap_or_default()),
+            _ => {}
+        };
+
+        Self::set_rtc_clock_source(clock_source);
+    }
+
     #[cfg(any(
         rtc_v2f0, rtc_v2f2, rtc_v2f3, rtc_v2f4, rtc_v2f7, rtc_v2h7, rtc_v2l0, rtc_v2l1, rtc_v2l4, rtc_v2wb, rtc_v3,
         rtc_v3u5
diff --git a/embassy-stm32/src/rcc/l4.rs b/embassy-stm32/src/rcc/l4.rs
index c6bccfd26..0083ae5bb 100644
--- a/embassy-stm32/src/rcc/l4.rs
+++ b/embassy-stm32/src/rcc/l4.rs
@@ -2,13 +2,13 @@ use core::marker::PhantomData;
 
 use embassy_hal_internal::into_ref;
 use stm32_metapac::rcc::regs::Cfgr;
-use stm32_metapac::rcc::vals::{Lsedrv, Mcopre, Mcosel};
+use stm32_metapac::rcc::vals::{Mcopre, Mcosel};
 
 pub use super::bus::{AHBPrescaler, APBPrescaler};
 use crate::gpio::sealed::AFType;
 use crate::gpio::Speed;
 use crate::pac::rcc::vals::{Hpre, Msirange, Pllsrc, Ppre, Sw};
-use crate::pac::{FLASH, PWR, RCC};
+use crate::pac::{FLASH, RCC};
 use crate::rcc::bd::{BackupDomain, RtcClockSource};
 use crate::rcc::{set_freqs, Clocks};
 use crate::time::Hertz;
@@ -407,36 +407,7 @@ pub(crate) unsafe fn init(config: Config) {
 
     RCC.apb1enr1().modify(|w| w.set_pwren(true));
 
-    match config.rtc_mux {
-        RtcClockSource::LSE => {
-            // 1. Unlock the backup domain
-            PWR.cr1().modify(|w| w.set_dbp(true));
-
-            // 2. Setup the LSE
-            RCC.bdcr().modify(|w| {
-                // Enable LSE
-                w.set_lseon(true);
-                // Max drive strength
-                // TODO: should probably be settable
-                w.set_lsedrv(Lsedrv::HIGH);
-            });
-
-            // Wait until LSE is running
-            while !RCC.bdcr().read().lserdy() {}
-
-            BackupDomain::set_rtc_clock_source(RtcClockSource::LSE);
-        }
-        RtcClockSource::LSI => {
-            // Turn on the internal 32 kHz LSI oscillator
-            RCC.csr().modify(|w| w.set_lsion(true));
-
-            // Wait until LSI is running
-            while !RCC.csr().read().lsirdy() {}
-
-            BackupDomain::set_rtc_clock_source(RtcClockSource::LSI);
-        }
-        _ => unreachable!(),
-    }
+    BackupDomain::configure_rtc(config.rtc_mux, None);
 
     let (sys_clk, sw) = match config.mux {
         ClockSrc::MSI(range) => {
diff --git a/embassy-stm32/src/rcc/wb.rs b/embassy-stm32/src/rcc/wb.rs
index 6496b41e1..efd964642 100644
--- a/embassy-stm32/src/rcc/wb.rs
+++ b/embassy-stm32/src/rcc/wb.rs
@@ -293,18 +293,6 @@ pub(crate) fn configure_clocks(config: &Config) {
         while !rcc.cr().read().hsirdy() {}
     }
 
-    let needs_lsi = if let Some(rtc_mux) = &config.rtc {
-        *rtc_mux == RtcClockSource::LSI
-    } else {
-        false
-    };
-
-    if needs_lsi {
-        rcc.csr().modify(|w| w.set_lsi1on(true));
-
-        while !rcc.csr().read().lsi1rdy() {}
-    }
-
     match &config.lse {
         Some(_) => {
             rcc.cfgr().modify(|w| w.set_stopwuck(true));
@@ -378,5 +366,5 @@ pub(crate) fn configure_clocks(config: &Config) {
 
     config
         .rtc
-        .map(|clock_source| BackupDomain::set_rtc_clock_source(clock_source));
+        .map(|clock_source| BackupDomain::configure_rtc(clock_source, None));
 }
diff --git a/embassy-stm32/src/rcc/wl.rs b/embassy-stm32/src/rcc/wl.rs
index 47be00ad8..7a03d9060 100644
--- a/embassy-stm32/src/rcc/wl.rs
+++ b/embassy-stm32/src/rcc/wl.rs
@@ -1,6 +1,6 @@
 pub use super::bus::{AHBPrescaler, APBPrescaler, VoltageScale};
 use crate::pac::rcc::vals::Adcsel;
-use crate::pac::{FLASH, PWR, RCC};
+use crate::pac::{FLASH, RCC};
 use crate::rcc::bd::{BackupDomain, RtcClockSource};
 use crate::rcc::{set_freqs, Clocks};
 use crate::time::Hertz;
@@ -234,36 +234,7 @@ pub(crate) unsafe fn init(config: Config) {
 
     while FLASH.acr().read().latency() != ws {}
 
-    match config.rtc_mux {
-        RtcClockSource::LSE => {
-            // 1. Unlock the backup domain
-            PWR.cr1().modify(|w| w.set_dbp(true));
-
-            // 2. Setup the LSE
-            RCC.bdcr().modify(|w| {
-                // Enable LSE
-                w.set_lseon(true);
-                // Max drive strength
-                // TODO: should probably be settable
-                w.set_lsedrv(Lsedrv::High as u8); //---// PAM - should not be commented
-            });
-
-            // Wait until LSE is running
-            while !RCC.bdcr().read().lserdy() {}
-
-            BackupDomain::set_rtc_clock_source(RtcClockSource::LSE);
-        }
-        RtcClockSource::LSI => {
-            // Turn on the internal 32 kHz LSI oscillator
-            RCC.csr().modify(|w| w.set_lsion(true));
-
-            // Wait until LSI is running
-            while !RCC.csr().read().lsirdy() {}
-
-            BackupDomain::set_rtc_clock_source(RtcClockSource::LSI);
-        }
-        _ => unreachable!(),
-    }
+    BackupDomain::configure_rtc(config.rtc_mux, None);
 
     match config.mux {
         ClockSrc::HSI16 => {