ath10k_temperature_sensor.cc

// Copyright 2015 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "thermald/ath10k_temperature_sensor.h"

#include <string>

#include "base/check.h"
#include "base/files/file_enumerator.h"
#include "base/files/file_path.h"
#include "base/logging.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/stringprintf.h"

#include "thermald/ath10k_interface.h"
#include "thermald/hwmon_temperature_sensor.h"
#include "thermald/network_interface.h"

using std::string;

namespace thermald {

static bool GetHwmonChipId(const string &interface_name, int *chip_id) {
  base::FilePath phy_hwmon_dir(base::StringPrintf(
      "/sys/class/net/%s/phy80211/device/hwmon", interface_name.c_str()));

  base::FileEnumerator hwmon_enum(phy_hwmon_dir, false,
                                  base::FileEnumerator::DIRECTORIES,
                                  FILE_PATH_LITERAL("hwmon*"));

  base::FilePath hwmon_dev = hwmon_enum.Next();
  if (hwmon_dev.empty()) {
    LOG(ERROR) << "ath10k interface '" << interface_name
               << "' has no thermal sensor";
    return false;
  }

  if (!hwmon_enum.Next().empty()) {
    LOG(ERROR) << "failed to determine thermal sensor of ath10k device '"
               << interface_name << "': more than one hwmon device";
    return false;
  }

  return base::StringToInt(hwmon_dev.BaseName().value().substr(5), chip_id);
}

Ath10kTemperatureSensor::Ath10kTemperatureSensor(
    const string &interface_name, const string &sensor_name)
    : TemperatureSensorCommon(sensor_name),
      interface_name_(interface_name),
      no_thermal_support_(false) {
}

Ath10kTemperatureSensor::Ath10kTemperatureSensor(
    const string &interface_name)
    : Ath10kTemperatureSensor(interface_name, interface_name) {
}

bool Ath10kTemperatureSensor::ReadTemperature(int *value) {
  DCHECK(value);

  if (no_thermal_support_) {
    return false;
  }

  if (!ath10k_interface_.get()) {
    if (!Initialize()) {
      return false;
    }
  }

  return hwmon_sensor_->ReadTemperature(value);
}

bool Ath10kTemperatureSensor::IsOperational() {
  if (no_thermal_support_) {
    return false;
  }

  if (!ath10k_interface_.get()) {
    // First check if the network interface exists at all before
    // checking for ath10k specifics in Initialize(). This helps
    // to reduce log clutter.
    if (!NetworkInterface::Exists(interface_name_)) {
      return false;
    }

    if (!Initialize()) {
      return false;
    }
  }

  // The sensor of ath10k interfaces can only be read when the interface is
  // activated.
  return ath10k_interface_->IsUp();
}

bool Ath10kTemperatureSensor::Initialize() {
  if (!Ath10kInterface::IsAth10kInterface(interface_name_)) {
    return false;
  }

  if (!Ath10kInterface::HasThermalSupport(interface_name_)) {
    no_thermal_support_ = true;
    return false;
  }

  int chip_id;
  if (!GetHwmonChipId(interface_name_, &chip_id)) {
    return false;
  }

  hwmon_sensor_.reset(
      new HwmonTemperatureSensor(chip_id, 1, name()));

  ath10k_interface_.reset(new Ath10kInterface(interface_name_));

  return true;
}

}  // namespace thermald