Add len_<foo> for non inner arrays.

This was just a missing API which made it hard to use arrays of registers.

Author: thejpster

examples/array.rs

@@ -44,4 +44,10 @@ fn main() {
     assert_eq!(ro_array_1, 0x3);
     println!("MMIO read-only array[0]: 0x{:X}", ro_array_0);
     println!("MMIO read-only array[1]: 0x{:X}", ro_array_1);
+
+    // Get the length of the arrays
+    assert_eq!(mmio_uart.len_array_0(), 4);
+    assert_eq!(mmio_uart.len_array_1(), 4);
+    assert_eq!(mmio_uart.len_array_read_only(), 4);
+    assert_eq!(mmio_uart.len_array_write_only(), 2);
 }

macro/src/lib.rs

@@ -839,6 +839,7 @@ impl FieldParser {
         let unchecked_write_fn_name = format_ident!("write_{}_unchecked", field_ident);
         let unchecked_modify_fn_name = format_ident!("modify_{}_unchecked", field_ident);
         let modify_fn_name = format_ident!("modify_{}", field_ident);
+        let array_len_func = format_ident!("len_{}", field_ident);
         let error_type = quote! { derive_mmio::OutOfBoundsError };
 
         access_methods.append_all(quote! {
@@ -858,6 +859,16 @@ impl FieldParser {
             }
         });
 
+        access_methods.append_all(quote! {
+            #[doc = "Length of the array `"]
+            #[doc = stringify!(#field_ident)]
+            #[doc = "`."]
+            #[inline]
+            pub const fn #array_len_func(&self) -> usize {
+                #array_len
+            }
+        });
+
         if let Some(read_access) = access.read {
             let mut opt_mut = TokenStream::new();
             if read_access == ReadAccess::Normal {

src/lib.rs

@@ -320,6 +320,10 @@ impl MmioUart {
     pub unsafe fn modify_bank_unchecked<F: FnOnce(u32) -> u32>(&mut self, index: usize, f: F) {
         // ...
     }
+
+    pub const fn len_bank(&self) -> usize {
+        4
+    }
 }
 ```