kapi: introduce driver and bus protocol

3 files changed, 69 insertions, 0 deletions

diff --git a/kernel/CMakeLists.txt b/kernel/CMakeLists.txt
index 9d3a83e2..72994449 100644
--- a/kernel/CMakeLists.txt
+++ b/kernel/CMakeLists.txt
@@ -15,6 +15,8 @@ target_sources("kernel_lib" PRIVATE
     "kapi/devices/bus.cpp"
     "kapi/devices/cpu.cpp"
     "kapi/devices/device.cpp"
+    "kapi/devices/driver.cpp"
+    "kapi/devices/error.cpp"
     "kapi/devices/interface_registry.cpp"
     "kapi/filesystem.cpp"
     "kapi/interrupts.cpp"
diff --git a/kernel/kapi/devices/driver.cpp b/kernel/kapi/devices/driver.cpp
new file mode 100644
index 00000000..c6b5e056
--- /dev/null
+++ b/kernel/kapi/devices/driver.cpp
@@ -0,0 +1,19 @@
+#include <kapi/devices.hpp>
+
+#include <cstdint>
+#include <optional>
+
+namespace kapi::devices
+{
+
+  auto driver::claimed_major() const -> std::optional<std::uint8_t>
+  {
+    return std::nullopt;
+  }
+
+  auto driver::query_interface(interface) -> void *
+  {
+    return nullptr;
+  }
+
+}  // namespace kapi::devices
diff --git a/kernel/kapi/devices/error.cpp b/kernel/kapi/devices/error.cpp
new file mode 100644
index 00000000..9d814fbe
--- /dev/null
+++ b/kernel/kapi/devices/error.cpp
@@ -0,0 +1,48 @@
+#include <kapi/devices/error.hpp>
+
+#include <kstd/system_error.hpp>
+
+#include <string_view>
+#include <utility>
+
+namespace kapi::devices
+{
+
+  namespace
+  {
+    struct driver_match_category_t final : kstd::error_category
+    {
+      [[nodiscard]] auto name() const noexcept -> std::string_view override
+      {
+        return "driver_match";
+      }
+
+      [[nodiscard]] auto message(int value) const noexcept -> std::string_view override
+      {
+        switch (static_cast<driver_match_errc>(value))
+        {
+          case driver_match_errc::no_match:
+            return "driver does not match this device";
+          default:
+            return "unknown driver matching error";
+        }
+      }
+
+      [[nodiscard]] auto default_error_condition(int value) const noexcept -> kstd::error_condition override
+      {
+        if (value == std::to_underlying(driver_match_errc::no_match))
+        {
+          return make_error_condition(kstd::errc::not_supported);
+        }
+        return kstd::error_category::default_error_condition(value);
+      }
+
+    } constexpr driver_match_category_instance{};
+  }  // namespace
+
+  auto driver_match_category() noexcept -> kstd::error_category const &
+  {
+    return driver_match_category_instance;
+  }
+
+}  // namespace kapi::devices
\ No newline at end of file