tlbmc/hal/sysfs/peci.cc

#include "tlbmc/hal/sysfs/peci.h"

#include <cstdint>
#include <fstream>
#include <string>

#include "absl/status/status.h"
#include "absl/strings/str_cat.h"
#include "hal_common_config.pb.h"

namespace milotic_tlbmc {

boost::filesystem::path PeciSysfs::GetBusPath(uint64_t bus) const {
  boost::filesystem::path path(config_.peci_sysfs_path);
  path /= "devices/peci-";
  return absl::StrCat(path.string(), bus);
}

boost::filesystem::path PeciSysfs::GetPeciDevicePath(uint64_t bus) const {
  return boost::filesystem::path(absl::StrCat(config_.peci_dev_path, bus));
}

boost::filesystem::path PeciSysfs::GetPeciRescanPath() const {
  // From: https://www.kernel.org/doc/html/latest/admin-guide/abi-testing.html#abi-sys-bus-peci-rescan
  return boost::filesystem::path(config_.peci_sysfs_path) / "rescan";
}

bool PeciSysfs::IsDevicePresent(const HalCommonConfig& config) const {
  boost::filesystem::path path = GetBusPath(config.bus());
  path /= GetDeviceDirectoryName(config);
  return boost::filesystem::exists(path);
}

absl::Status PeciSysfs::DeleteDevice(const HalCommonConfig& config) const {
  // No `IsDevicePresent` check on this like in `NewDevice`, since it
  // might be used to clean up after a device instantiation that was only
  // partially successful

  boost::filesystem::path path = GetBusPath(config.bus()) / "delete_device";
  std::ofstream file(path.string());
  if (!file.good()) {
    return absl::InternalError(absl::StrCat("Failed to open ", path.string()));
  }

  // Peci requires explicitly passing driver name when deleting device.
  // From
  // https://github.com/openbmc/dbus-sensors/blob/master/src/intel-cpu/IntelCPUSensorMain.cpp#L463
  file << absl::StrCat("peci-client 0x", absl::Hex(config.address())) << "\n";
  file.flush();
  if (!file.good()) {
    return absl::InternalError(
        absl::StrCat("Failed to write to ", path.string()));
  }

  return absl::OkStatus();
}

std::string PeciSysfs::GetDeviceDirectoryName(
    const HalCommonConfig& config) const {
  return absl::StrCat(config.bus(), "-", absl::Hex(config.address()));
}

}  // namespace milotic_tlbmc