tlbmc/sensors/i2c_hwmon_based_sensor.cc

#include "tlbmc/sensors/i2c_hwmon_based_sensor.h"

#include <memory>
#include <optional>
#include <string>
#include <string_view>
#include <utility>

#include "google/protobuf/duration.pb.h"
#include "absl/log/log.h"
#include "absl/status/status.h"
#include "absl/status/statusor.h"
#include "absl/strings/match.h"
#include "absl/strings/str_cat.h"
#include "boost/asio.hpp"  // NOLINT: boost::asio is commonly used in BMC
#include "boost/asio/error.hpp"  // NOLINT
#include "boost/asio/random_access_file.hpp"  // NOLINT: boost::asio is commonly used in BMC
#include "boost/filesystem.hpp"  // NOLINT: boost::filesystem is commonly used in BMC
#include "boost/filesystem/operations.hpp"  // NOLINT
#include "boost/system/detail/error_code.hpp"  // NOLINT: boost::asio is commonly used in BMC
#include "hwmon_temp_sensor_config.pb.h"
#include "i2c_common_config.pb.h"
#include "tlbmc/hal/sysfs/i2c.h"
#include "resource.pb.h"
#include "sensor.pb.h"
#include "tlbmc/sensors/hwmon_based_sensor.h"

namespace milotic_tlbmc {

I2cHwmonBasedSensor::I2cHwmonBasedSensor(
    const std::string& input_dev_path,
    const std::shared_ptr<boost::asio::io_context>& io_context,
    SensorAttributesStatic&& sensor_attributes_static,
    std::optional<NotificationCb> on_batch_notify)
    : HwmonBasedSensor(input_dev_path, io_context,
                       std::move(sensor_attributes_static), on_batch_notify) {}

absl::StatusOr<boost::filesystem::path>
I2cHwmonBasedSensor::CreateDeviceAndReturnsHwmonPath(
    const I2cCommonConfig& i2c_config, std::string_view driver_name,
    const I2cSysfs& i2c_sysfs) {
  // If the device is already created, in the current implementation we don't
  // create it again.
  if (absl::Status status = i2c_sysfs.NewDevice(i2c_config, driver_name);
      !status.ok() && status.code() != absl::StatusCode::kAlreadyExists) {
    return status;
  }

  if (!i2c_sysfs.IsDevicePresent(i2c_config)) {
    return absl::InternalError(absl::StrCat("Failed to find device ",
                                            i2c_config, " after creating it"));
  }

  // Now the device is created, e.g.,
  // /sys/bus/i2c/devices/i2c-24/24-005c/
  boost::filesystem::path device_path =
      i2c_sysfs.Geti2cBusPath(i2c_config.bus()) /
      I2cSysfs::GetDeviceDirectoryName(i2c_config);

  if (!boost::filesystem::is_directory(device_path / "hwmon")) {
    return absl::InternalError(
        absl::StrCat("Failed to find hwmon under ", device_path.string()));
  }

  boost::filesystem::path hwmon_path;
  bool found_hwmon = false;
  for (const auto& entry :
       boost::filesystem::directory_iterator(device_path / "hwmon")) {
    // Look for something like hwmon10
    if (absl::StartsWith(entry.path().filename().string(), "hwmon")) {
      found_hwmon = true;
      hwmon_path = entry.path();
      break;
    }
  }

  if (!found_hwmon) {
    return absl::InternalError(
        absl::StrCat("Failed to find hwmon for ", device_path.string()));
  }
  return hwmon_path;
}

}  // namespace milotic_tlbmc