feat(stm32-l): provide a const constructor on rcc::Config

embassy-stm32/src/rcc/bd.rs

@@ -92,6 +92,16 @@ pub struct LsConfig {
 }
 
 impl LsConfig {
+    pub const fn new() -> Self {
+        // on L5, just the fact that LSI is enabled makes things crash.
+        // TODO: investigate.
+
+        #[cfg(not(stm32l5))]
+        return Self::default_lsi();
+        #[cfg(stm32l5)]
+        return Self::off();
+    }
+
     pub const fn default_lse() -> Self {
         Self {
             rtc: RtcClockSource::LSE,
@@ -124,13 +134,7 @@ impl LsConfig {
 
 impl Default for LsConfig {
     fn default() -> Self {
-        // on L5, just the fact that LSI is enabled makes things crash.
-        // TODO: investigate.
-
-        #[cfg(not(stm32l5))]
-        return Self::default_lsi();
-        #[cfg(stm32l5)]
-        return Self::off();
+        Self::new()
     }
 }
 

embassy-stm32/src/rcc/hsi48.rs

@@ -18,9 +18,15 @@ pub struct Hsi48Config {
     pub sync_from_usb: bool,
 }
 
+impl Hsi48Config {
+    pub const fn new() -> Self {
+        Self { sync_from_usb: false }
+    }
+}
+
 impl Default for Hsi48Config {
     fn default() -> Self {
-        Self { sync_from_usb: false }
+        Self::new()
     }
 }
 

embassy-stm32/src/rcc/l.rs

@@ -68,9 +68,9 @@ pub struct Config {
     pub mux: super::mux::ClockMux,
 }
 
-impl Default for Config {
+impl Config {
     #[inline]
-    fn default() -> Config {
+    pub const fn new() -> Self {
         Config {
             hse: None,
             hsi: false,
@@ -90,15 +90,22 @@ impl Default for Config {
             #[cfg(any(stm32l47x, stm32l48x, stm32l49x, stm32l4ax, rcc_l4plus, stm32l5))]
             pllsai2: None,
             #[cfg(crs)]
-            hsi48: Some(Default::default()),
-            ls: Default::default(),
+            hsi48: Some(crate::rcc::Hsi48Config::new()),
+            ls: crate::rcc::LsConfig::new(),
             #[cfg(any(stm32l0, stm32l1))]
             voltage_scale: VoltageScale::RANGE1,
-            mux: Default::default(),
+            mux: super::mux::ClockMux::default(),
         }
     }
 }
 
+impl Default for Config {
+    #[inline]
+    fn default() -> Config {
+        Self::new()
+    }
+}
+
 #[cfg(stm32wb)]
 pub const WPAN_DEFAULT: Config = Config {
     hse: Some(Hse {