Add macro support for register arrays

I'm experimenting with a RAL code generator that collapses contiguous
register arrays. The generated code would resemble

    pub struct RegisterBlock {
        pub MY_ARRAY: [RWRegister<u32>; 3],
    }

and an individual register would be addressed like

    ral::read_reg!(ral::my_mod, my_inst, MY_ARRAY[1]);

This commit extends the four macros so that we can specify an array
offset. We simply need to match zero or more `[N]` patterns, where `N`
is some expression that produces an array offset. The included test case
shows that the approach should support multi-dimensional arrays.

1 files changed, 20 insertions, 20 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 52401d6..c65e94b 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -275,11 +275,11 @@ impl<T: Copy> UnsafeWORegister<T> {
 /// and the macro brings such constants into scope and then dereferences the provided reference.
 #[macro_export]
 macro_rules! write_reg {
-    ( $periph:path, $instance:expr, $reg:ident, $( $field:ident : $value:expr ),+ ) => {{
+    ( $periph:path, $instance:expr, $reg:ident $([$offset:expr])*, $( $field:ident : $value:expr ),+ ) => {{
         #[allow(unused_imports)]
         use $periph::{*};
         #[allow(unused_imports)]
-        (*$instance).$reg.write(
+        (*$instance).$reg $([$offset])*.write(
             $({
                 use $periph::{$reg::$field::{W::*, RW::*}};
                 ($value << { use $periph::{$reg::$field::offset}; offset })
@@ -287,10 +287,10 @@ macro_rules! write_reg {
             }) | *
         );
     }};
-    ( $periph:path, $instance:expr, $reg:ident, $value:expr ) => {{
+    ( $periph:path, $instance:expr, $reg:ident $([$offset:expr])*, $value:expr ) => {{
         #[allow(unused_imports)]
         use $periph::{*};
-        (*$instance).$reg.write($value);
+        (*$instance).$reg $([$offset])*.write($value);
     }};
 }
 
@@ -408,12 +408,12 @@ macro_rules! write_reg {
 /// and the macro brings such constants into scope and then dereferences the provided reference.
 #[macro_export]
 macro_rules! modify_reg {
-    ( $periph:path, $instance:expr, $reg:ident, $( $field:ident : $value:expr ),+ ) => {{
+    ( $periph:path, $instance:expr, $reg:ident $([$offset:expr])*, $( $field:ident : $value:expr ),+ ) => {{
         #[allow(unused_imports)]
         use $periph::{*};
         #[allow(unused_imports)]
-        (*$instance).$reg.write(
-            ((*$instance).$reg.read() & !( $({ use $periph::{$reg::$field::mask}; mask }) | * ))
+        (*$instance).$reg $([$offset])*.write(
+            ((*$instance).$reg $([$offset])*.read() & !( $({ use $periph::{$reg::$field::mask}; mask }) | * ))
             | $({
                 use $periph::{$reg::$field::{W::*, RW::*}};
                 ($value << { use $periph::{$reg::$field::offset}; offset })
@@ -421,10 +421,10 @@ macro_rules! modify_reg {
             }) | *
         );
     }};
-    ( $periph:path, $instance:expr, $reg:ident, $fn:expr ) => {{
+    ( $periph:path, $instance:expr, $reg:ident $([$offset:expr])*, $fn:expr ) => {{
         #[allow(unused_imports)]
         use $periph::{*};
-        (*$instance).$reg.write($fn((*$instance).$reg.read()));
+        (*$instance).$reg $([$offset])*.write($fn((*$instance).$reg $([$offset])*.read()));
     }};
 }
 
@@ -527,27 +527,27 @@ macro_rules! modify_reg {
 /// and the macro brings such constants into scope and then dereferences the provided reference.
 #[macro_export]
 macro_rules! read_reg {
-    ( $periph:path, $instance:expr, $reg:ident, $( $field:ident ),+ ) => {{
+    ( $periph:path, $instance:expr, $reg:ident $([$offset:expr])*, $( $field:ident ),+ ) => {{
         #[allow(unused_imports)]
         use $periph::{*};
-        let val = ((*$instance).$reg.read());
+        let val = ((*$instance).$reg $([$offset])*.read());
         ( $({
             #[allow(unused_imports)]
             use $periph::{$reg::$field::{mask, offset, R::*, RW::*}};
             (val & mask) >> offset
         }) , *)
     }};
-    ( $periph:path, $instance:expr, $reg:ident, $field:ident $($cmp:tt)* ) => {{
+    ( $periph:path, $instance:expr, $reg:ident $([$offset:expr])*, $field:ident $($cmp:tt)* ) => {{
         #[allow(unused_imports)]
         use $periph::{*};
         #[allow(unused_imports)]
         use $periph::{$reg::$field::{mask, offset, R::*, RW::*}};
-        (((*$instance).$reg.read() & mask) >> offset) $($cmp)*
+        (((*$instance).$reg $([$offset])*.read() & mask) >> offset) $($cmp)*
     }};
-    ( $periph:path, $instance:expr, $reg:ident ) => {{
+    ( $periph:path, $instance:expr, $reg:ident $([$offset:expr])* ) => {{
         #[allow(unused_imports)]
         use $periph::{*};
-        ((*$instance).$reg.read())
+        ((*$instance).$reg $([$offset])*.read())
     }};
 }
 
@@ -624,20 +624,20 @@ macro_rules! read_reg {
 /// `GPIOA` they are not the same thing.
 #[macro_export]
 macro_rules! reset_reg {
-    ( $periph:path, $instance:expr, $instancemod:path, $reg:ident, $( $field:ident ),+ ) => {{
+    ( $periph:path, $instance:expr, $instancemod:path, $reg:ident $([$offset:expr])*, $( $field:ident ),+ ) => {{
         #[allow(unused_imports)]
         use $periph::{*};
         use $periph::{$instancemod::{reset}};
         #[allow(unused_imports)]
-        (*$instance).$reg.write({
+        (*$instance).$reg $([$offset])*.write({
             let resetmask: u32 = $({ use $periph::{$reg::$field::mask}; mask }) | *;
-            ((*$instance).$reg.read() & !resetmask) | (reset.$reg & resetmask)
+            ((*$instance).$reg $([$offset])*.read() & !resetmask) | (reset.$reg & resetmask)
         });
     }};
-    ( $periph:path, $instance:expr, $instancemod:path, $reg:ident ) => {{
+    ( $periph:path, $instance:expr, $instancemod:path, $reg:ident $([$offset:expr])*) => {{
         #[allow(unused_imports)]
         use $periph::{*};
         use $periph::{$instancemod::{reset}};
-        (*$instance).$reg.write(reset.$reg);
+        (*$instance).$reg $([$offset])*.write(reset.$reg);
     }};
 }