diff --git a/src/common.rs b/src/common.rs
index 7bfe716bc3725604ad1f7b3b4debf49a825e3337..afe9562fb9c70af054cbc6325970412387dffbb9 100644
--- a/src/common.rs
+++ b/src/common.rs
@@ -27,6 +27,12 @@ pub use Polarity::*;
 pub type ControllerId = u32;
 pub type ChannelIndex = u32;
 
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, Hash, PartialOrd)]
+pub struct PortId {
+    pub(crate) controller_id: ControllerId,
+    pub(crate) port_index: u32,
+}
+
 #[derive(Debug, Clone, Eq, PartialEq, Ord, PartialOrd)]
 pub struct Payload(Arc<Vec<u8>>);