add platform device

Signed-off-by: Pascal Bauer <pascal.bauer@rwth-aachen.de>

common/include/villas/kernel/devices/platform_device.hpp

@@ -0,0 +1,52 @@
+/* Platform Device
+ *
+ * Author: Pascal Bauer <pascal.bauer@rwth-aachen.de>
+ *
+ * SPDX-FileCopyrightText: 2023-2024 Pascal Bauer <pascal.bauer@rwth-aachen.de>
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#pragma once
+
+#include <filesystem>
+#include <villas/kernel/devices/device.hpp>
+#include <villas/kernel/devices/driver.hpp>
+#include <villas/kernel/devices/utils.hpp>
+
+namespace villas {
+namespace kernel {
+namespace devices {
+
+class PlatformDevice : public Device {
+private:
+  static constexpr char PROBE_DEFAULT[] = "/sys/bus/platform/drivers_probe";
+  static constexpr char OVERRIDE_DEFAULT[] = "driver_override";
+
+private:
+  const std::filesystem::path m_path;
+  const std::filesystem::path m_probe_path;
+  const std::filesystem::path m_override_path;
+
+public:
+  PlatformDevice(const std::filesystem::path path)
+      : PlatformDevice(path, std::filesystem::path(PROBE_DEFAULT),
+                       path / std::filesystem::path(OVERRIDE_DEFAULT)){};
+
+  PlatformDevice(const std::filesystem::path path,
+                 const std::filesystem::path probe_path,
+                 const std::filesystem::path override_path)
+      : m_path(path), m_probe_path(probe_path),
+        m_override_path(override_path){};
+
+  // Implement device interface
+  std::optional<std::unique_ptr<Driver>> driver() const override;
+  std::optional<int> iommu_group() const override;
+  std::string name() const override;
+  std::filesystem::path override_path() const override;
+  std::filesystem::path path() const override;
+  void probe() const override;
+};
+
+} // namespace devices
+} // namespace kernel
+} // namespace villas

common/lib/kernel/devices/platform_device.cpp

@@ -0,0 +1,54 @@
+/* Platform Device
+ *
+ * Author: Pascal Bauer <pascal.bauer@rwth-aachen.de>
+ *
+ * SPDX-FileCopyrightText: 2023-2024 Pascal Bauer <pascal.bauer@rwth-aachen.de>
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <villas/kernel/devices/platform_device.hpp>
+#include <villas/kernel/devices/generic_driver.hpp>
+
+using villas::kernel::devices::Driver, villas::kernel::devices::GenericDriver;
+using villas::kernel::devices::PlatformDevice;
+using villas::kernel::devices::utils::write_to_file;
+
+std::optional<std::unique_ptr<Driver>> PlatformDevice::driver() const {
+  std::filesystem::path driver_symlink =
+      this->m_path / std::filesystem::path("driver");
+
+  if (!std::filesystem::is_symlink(driver_symlink))
+    return std::nullopt;
+
+  std::filesystem::path driver_path =
+      std::filesystem::canonical(driver_symlink);
+  return std::make_optional(std::make_unique<GenericDriver>(driver_path));
+}
+
+std::optional<int> PlatformDevice::iommu_group() const {
+  std::filesystem::path symlink =
+      std::filesystem::path(this->m_path.u8string() + "/iommu_group");
+
+  std::filesystem::path link;
+  link = std::filesystem::read_symlink(symlink);
+
+  std::string delimiter = "iommu_groups/";
+  int pos = link.u8string().find(delimiter);
+  int iommu_group = std::stoi(link.u8string().substr(pos + delimiter.length()));
+  return std::make_optional<int>(iommu_group);
+}
+
+std::filesystem::path PlatformDevice::path() const { return this->m_path; };
+
+void PlatformDevice::probe() const {
+  write_to_file(this->name(), this->m_probe_path);
+}
+
+std::filesystem::path PlatformDevice::override_path() const {
+  return this->m_override_path;
+}
+
+std::string PlatformDevice::name() const {
+  size_t pos = this->m_path.u8string().rfind('/');
+  return this->m_path.u8string().substr(pos + 1);
+}