common: Add the register module.

[gps-watch.git] / src / common / register.rs

diff --git a/src/common/register.rs b/src/common/register.rs
new file mode 100644 (file)
index 0000000..9a3f3c3
--- /dev/null
+++ b/src/common/register.rs
@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2019 Tilman Sauerbeck (tilman at code-monkey de)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+use core::ptr;
+use core::marker::PhantomData;
+
+pub struct Register<T>
+{
+    pub address: u32,
+    phantom: PhantomData<T>,
+}
+
+impl<T> Register<T> {
+    pub fn new(addr: u32) -> Register<T> {
+        Register {
+            address: addr,
+            phantom: PhantomData,
+        }
+    }
+
+    pub fn read(&self) -> T {
+        let ptr = self.address as *const T;
+
+        unsafe { ptr::read_volatile(ptr) }
+    }
+
+    pub fn write(&mut self, value: T) {
+        let ptr = self.address as *mut T;
+
+        unsafe { ptr::write_volatile(ptr, value) }
+    }
+
+    pub fn modify<F>(&mut self, func: F)
+        where F: FnOnce(T) -> T
+    {
+        let mut v = self.read();
+        v = func(v);
+        self.write(v);
+    }
+}