fix Debug::fmt for FMT register

Author: burrbull

ci/script.sh

@@ -47,7 +47,7 @@ main() {
         echo 'portable-atomic = { version = "1.4", default-features = false }' >> $td/Cargo.toml
     fi
     if [[ "$options" == *"--impl_defmt"* ]]; then
-        echo 'defmt = "0.3.5"' >> $td/Cargo.toml
+        echo 'defmt = { version = "0.3.5", optional = true }' >> $td/Cargo.toml
     fi
     echo '[profile.dev]'         >> $td/Cargo.toml
     echo 'incremental = false'   >> $td/Cargo.toml

src/generate/register.rs

@@ -309,7 +309,7 @@ pub fn render_register_mod(
             #debug_feature
             impl core::fmt::Debug for crate::generic::Reg<#regspec_ident> {
                 fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
-                    self.read().fmt(f)
+                    core::fmt::Debug::fmt(&self.read(), f)
                 }
             }
         });
@@ -491,7 +491,7 @@ fn render_register_mod_debug(
             #debug_feature
             impl core::fmt::Debug for crate::generic::Reg<#regspec_ident> {
                 fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
-                    self.read().fmt(f)
+                    core::fmt::Debug::fmt(&self.read(), f)
                 }
             }
         });