From 7c807a8605fb8104599bb8c4c1ddab579e6f5aef Mon Sep 17 00:00:00 2001
From: Jakob Bornecrantz <jakob@collabora.com>
Date: Tue, 3 Nov 2020 19:03:06 +0000
Subject: [PATCH] xrt: Add device driver provided bindings

---
 doc/changes/xrt/mr.587.md        |  4 +++
 src/xrt/include/xrt/xrt_device.h | 50 ++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+)
 create mode 100644 doc/changes/xrt/mr.587.md

diff --git a/doc/changes/xrt/mr.587.md b/doc/changes/xrt/mr.587.md
new file mode 100644
index 000000000..c1cfb3f51
--- /dev/null
+++ b/doc/changes/xrt/mr.587.md
@@ -0,0 +1,4 @@
+Add `xrt_binding_profile` struct, related pair structs and fields on
+`xrt_device` to allow to move the static rebinding of inputs and outputs into
+device drivers. This makes it easier to get a overview in the driver itself
+which bindings it can bind to.
diff --git a/src/xrt/include/xrt/xrt_device.h b/src/xrt/include/xrt/xrt_device.h
index 087188b56..01e6a7b23 100644
--- a/src/xrt/include/xrt/xrt_device.h
+++ b/src/xrt/include/xrt/xrt_device.h
@@ -167,11 +167,56 @@ struct xrt_input
 	union xrt_input_value value;
 };
 
+/*!
+ * A single named output, that sits on a @ref xrt_device.
+ *
+ * @ingroup xrt_iface
+ */
 struct xrt_output
 {
 	enum xrt_output_name name;
 };
 
+
+/*!
+ * A binding pair, going @p from a binding point to a @p device input.
+ *
+ * @ingroup xrt_iface
+ */
+struct xrt_binding_input_pair
+{
+	enum xrt_input_name from;   //!< From which name.
+	enum xrt_input_name device; //!< To input on the device.
+};
+
+/*!
+ * A binding pair, going @p from a binding point to a @p device output.
+ *
+ * @ingroup xrt_iface
+ */
+struct xrt_binding_output_pair
+{
+	enum xrt_output_name from;   //!< From which name.
+	enum xrt_output_name device; //!< To output on the device.
+};
+
+/*!
+ * A binding profile, has lists of binding pairs to goes from device in @p name
+ * to the device it hangs off on.
+ *
+ * @ingroup xrt_iface
+ */
+struct xrt_binding_profile
+{
+	//! Device this binding emulates.
+	enum xrt_device_name name;
+
+	struct xrt_binding_input_pair *inputs;
+	size_t num_inputs;
+	struct xrt_binding_output_pair *outputs;
+	size_t num_outputs;
+};
+
 /*!
  * @interface xrt_device
  *
@@ -194,6 +239,11 @@ struct xrt_device
 	//! Always set, pointing to the tracking system for this device.
 	struct xrt_tracking_origin *tracking_origin;
 
+	//! Number of bindings.
+	size_t num_binding_profiles;
+	// Array of alternative binding profiles.
+	struct xrt_binding_profile *binding_profiles;
+
 	//! Number of inputs.
 	size_t num_inputs;
 	//! Array of input structs.