1 files changed, 95 insertions, 0 deletions
diff --git a/src/pipe/register.rs b/src/pipe/register.rs
new file mode 100644
index 0000000..555b70a
--- /dev/null
+++ b/src/pipe/register.rs
@@ -0,0 +1,95 @@
+//! Generic register access.
+
+use core::marker::PhantomData;
+use vcell::VolatileCell;
+
+pub trait Readable {}
+pub trait Writable {}
+
+pub struct Register<T, Reg> {
+    value: VolatileCell<T>,
+    _marker: PhantomData<Reg>,
+}
+
+impl<T, Reg> From<T> for Register<T, Reg> {
+    fn from(v: T) -> Self {
+        Self {
+            value: VolatileCell::new(v),
+            _marker: PhantomData,
+        }
+    }
+}
+
+impl<T, Reg> Register<T, Reg>
+where
+    Self: Readable,
+    T: Copy,
+{
+    pub fn read(&self) -> R<T, Self> {
+        R {
+            bits: self.value.get(),
+            _marker: PhantomData,
+        }
+    }
+}
+
+impl<T, Reg> Register<T, Reg>
+where
+    Self: Readable + Writable,
+    T: Copy,
+{
+    pub fn write<F>(&self, f: F)
+    where
+        F: FnOnce(&mut W<T, Self>) -> &mut W<T, Self>,
+    {
+        let mut w = W {
+            bits: self.value.get(),
+            _marker: PhantomData,
+        };
+        self.value.set(f(&mut w).bits);
+    }
+
+    pub fn modify<F>(&self, f: F)
+    where
+        F: FnOnce(T, &mut W<T, Self>) -> &mut W<T, Self>,
+    {
+        let mut w = W {
+            bits: self.value.get(),
+            _marker: PhantomData,
+        };
+        self.value.set(f(w.bits, &mut w).bits);
+    }
+}
+
+pub struct R<T, Reg> {
+    pub bits: T,
+    _marker: PhantomData<Reg>,
+}
+
+impl<T, Reg> R<T, Reg>
+where
+    T: Copy,
+{
+    pub fn new(bits: T) -> Self {
+        Self {
+            bits,
+            _marker: PhantomData,
+        }
+    }
+
+    pub fn bits(&self) -> T {
+        self.bits
+    }
+}
+
+pub struct W<T, Reg> {
+    pub bits: T,
+    _marker: PhantomData<Reg>,
+}
+
+impl<T, Reg> W<T, Reg> {
+    pub unsafe fn bits(&mut self, bits: T) -> &mut Self {
+        self.bits = bits;
+        self
+    }
+}