From fbc31c3e385363f9eaba93238756a739e09ce873 Mon Sep 17 00:00:00 2001
From: Felix Morgner <felix.morgner@ost.ch>
Date: Thu, 23 Jul 2026 21:09:34 +0200
Subject: kapi: add driver registry

---
 kapi/kapi/devices/bus.hpp             |  5 ++++
 kapi/kapi/devices/device.hpp          | 27 +++++++++++++++++++
 kapi/kapi/devices/driver_registry.hpp | 51 +++++++++++++++++++++++++++++++++++
 kapi/kapi/devices/manager.hpp         |  6 +++++
 kapi/kapi/test_support/devices.hpp    |  1 +
 5 files changed, 90 insertions(+)
 create mode 100644 kapi/kapi/devices/driver_registry.hpp

(limited to 'kapi')

diff --git a/kapi/kapi/devices/bus.hpp b/kapi/kapi/devices/bus.hpp
index 6356e166..0e654072 100644
--- a/kapi/kapi/devices/bus.hpp
+++ b/kapi/kapi/devices/bus.hpp
@@ -41,6 +41,11 @@ namespace kapi::devices
 
     [[nodiscard]] auto children() const -> std::span<kstd::shared_ptr<device> const>;
 
+    //! Get this bus's protocol facet, if present.
+    //!
+    //! @return this bus's protocol facet if it has one, nullptr otherwise.
+    [[nodiscard]] virtual auto protocol() -> struct bus_protocol *;
+
   protected:
     //! Enumerate the devices on the bus.
     //!
diff --git a/kapi/kapi/devices/device.hpp b/kapi/kapi/devices/device.hpp
index 6ffd052d..c1b2065b 100644
--- a/kapi/kapi/devices/device.hpp
+++ b/kapi/kapi/devices/device.hpp
@@ -14,6 +14,15 @@ namespace kapi::devices
   //! @addtogroup kapi-devices-kernel-defined
   //! @{
 
+  enum struct state
+  {
+    uninitialized,
+    present,
+    bound,
+    failed,
+    removed,
+  };
+
   /**
    * @brief Base device identified by a name.
    */
@@ -65,6 +74,21 @@ namespace kapi::devices
     //! @return a shared pointer to the parent bus, or nullptr if this device has no parent.
     [[nodiscard]] auto parent() const -> kstd::shared_ptr<struct bus>;
 
+    //! Get this devices current state.
+    [[nodiscard]] auto state() const noexcept -> state;
+
+    //! Set the lifecycle state of this device.
+    auto set_state(enum state state) -> void;
+
+    //! Bind this device to the given driver.
+    auto bind_driver(kstd::weak_ptr<struct driver> driver) -> void;
+
+    //! Get the driver data associated with this device.
+    [[nodiscard]] auto driver_data() const -> kstd::shared_ptr<void> const &;
+
+    //! Set the driver data for this device.
+    auto set_driver_data(kstd::shared_ptr<void> data) -> void;
+
   protected:
     auto virtual query_interface(interface interface) -> void *;
 
@@ -75,6 +99,9 @@ namespace kapi::devices
 
     kstd::string m_name;
     kstd::weak_ptr<bus> m_parent;
+    devices::state m_state{state::uninitialized};
+    kstd::weak_ptr<struct driver> m_driver{};
+    kstd::shared_ptr<void> m_driver_data{};
   };
 
   //! @}
diff --git a/kapi/kapi/devices/driver_registry.hpp b/kapi/kapi/devices/driver_registry.hpp
new file mode 100644
index 00000000..26a81678
--- /dev/null
+++ b/kapi/kapi/devices/driver_registry.hpp
@@ -0,0 +1,51 @@
+#ifndef TEACHOS_KAPI_DEVICES_DRIVER_REGISTRY_HPP
+#define TEACHOS_KAPI_DEVICES_DRIVER_REGISTRY_HPP
+
+#include <kapi/devices/device.hpp>
+#include <kapi/devices/driver.hpp>
+
+#include <kstd/memory.hpp>
+#include <kstd/vector.hpp>
+
+namespace kapi::devices
+{
+
+  //! @addtogroup kapi-devices-kernel-defined
+  //! @{
+
+  struct driver_registry
+  {
+    driver_registry() = default;
+
+    auto static init() -> void;
+
+    auto static get() -> driver_registry &;
+
+    //! Register a new driver.
+    //!
+    //! The driver will be tried against all devices in the device tree that are not yet bound by a different driver.
+    //!
+    //! @param driver The driver to register.
+    auto add(kstd::shared_ptr<driver> driver) -> void;
+
+    //! Notify the registry about a new device having been attached to the device tree.
+    //!
+    //! The device will be tried against all currently registered drivers.
+    //!
+    //! @param device The device that was attached.
+    auto device_attached(kstd::shared_ptr<device> const & device) -> void;
+
+  private:
+    //! Try to bind a given device against every currently registered driver, if it is not bound yet.
+    //!
+    //! Driver matching will occur in driver registration order. The highest priority driver will win.
+    auto try_bind(kstd::shared_ptr<device> const & device) -> void;
+
+    kstd::vector<kstd::shared_ptr<driver>> m_drivers;
+  };
+
+  //! @}
+
+}  // namespace kapi::devices
+
+#endif
\ No newline at end of file
diff --git a/kapi/kapi/devices/manager.hpp b/kapi/kapi/devices/manager.hpp
index 5b620b27..de6ebf97 100644
--- a/kapi/kapi/devices/manager.hpp
+++ b/kapi/kapi/devices/manager.hpp
@@ -6,6 +6,7 @@
 #include <kapi/devices/device.hpp>
 
 #include <kstd/memory.hpp>
+#include <kstd/vector.hpp>
 
 #include <string_view>
 
@@ -33,6 +34,11 @@ namespace kapi::devices
   //! @return a shared pointer to the device iff. the device was found and is still alive, nullptr otherwise.
   auto find_device(std::string_view name) -> kstd::shared_ptr<device>;
 
+  //! Get all currently registered devices.
+  //!
+  //! @return every device current reachable through the registry.
+  [[nodiscard]] auto all() -> kstd::vector<kstd::shared_ptr<device>>;
+
   //! @}
 
 }  // namespace kapi::devices
diff --git a/kapi/kapi/test_support/devices.hpp b/kapi/kapi/test_support/devices.hpp
index ab0911fc..b4d410d6 100644
--- a/kapi/kapi/test_support/devices.hpp
+++ b/kapi/kapi/test_support/devices.hpp
@@ -5,6 +5,7 @@ namespace kapi::test_support::devices
 {
   auto deinit() -> void;
   auto deinit_interface_registry() -> void;
+  auto deinit_driver_registry() -> void;
 }  // namespace kapi::test_support::devices
 
 #endif
-- 
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