rtio_clocking: warn on unsupported settings

src/runtime/src/rtio_clocking.rs

@@ -99,7 +99,7 @@ fn init_drtio(timer: &mut GlobalTimer)
 #[cfg(has_si5324)]
 fn setup_si5324(i2c: &mut I2c, timer: &mut GlobalTimer, clk: RtioClock) {
     let si5324_settings = match clk {
-        _ => { // 125MHz output, from crystal, 7 Hz, default, also covers RtioClock::Int_125
+        RtioClock::Int_125 => { // 125MHz output, from crystal, 7 Hz
             info!("using internal 125MHz RTIO clock");
             si5324::FrequencySettings {
                 n1_hs  : 10,
@@ -112,6 +112,19 @@ fn setup_si5324(i2c: &mut I2c, timer: &mut GlobalTimer, clk: RtioClock) {
                 crystal_ref: true
             }
         }
+        _ => { // same setting  as Int_125, but fallback to default
+            warn!("rtio_clock setting '{:x}' is unsupported. Falling back to default internal 125MHz RTIO clock.");
+            si5324::FrequencySettings {
+                n1_hs  : 10,
+                nc1_ls : 4,
+                n2_hs  : 10,
+                n2_ls  : 19972,
+                n31    : 4565,
+                n32    : 4565,
+                bwsel  : 4,
+                crystal_ref: true
+            }
+        }
     };
     let si5324_ref_input = si5324::Input::Ckin2;
     si5324::setup(i2c, &si5324_settings, si5324_ref_input, timer).expect("cannot initialize Si5324");