[sensors][CrOS/Linux] Implementation of motion sensors for CrOS/Linux platforms

device/generic_sensor/linux/platform_sensor_utils_linux.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef DEVICE_GENERIC_SENSOR_LINUX_PLATFORM_SENSOR_UTILS_LINUX_H_
 #define DEVICE_GENERIC_SENSOR_LINUX_PLATFORM_SENSOR_UTILS_LINUX_H_
 
 #include "base/files/file_path.h"
 #include "base/memory/ptr_util.h"
 #include "device/generic_sensor/generic_sensor_export.h"
+#include "device/generic_sensor/linux/sensor_data_linux.h"
 
 namespace device {
 
 struct SensorDataLinux;
 struct SensorReading;
 
 // Generic reader class that reads sensors data from
 // sensors files located in the base iio folder.
 class DEVICE_GENERIC_SENSOR_EXPORT SensorReader {
  public:
   ~SensorReader();
 
   // Creates a new instance of SensorReader if sensor read files
   // has been found and |sensor_paths_| are set.
   static std::unique_ptr<SensorReader> Create(const SensorDataLinux& data);
 
   // Reads sensor values into |*reading| from sensor files
   // specified in |sensor_paths_|.
   bool ReadSensorReading(SensorReading* reading);
 
  private:
-  explicit SensorReader(std::vector<base::FilePath> sensor_paths);
+  SensorReader(std::vector<base::FilePath> sensor_paths,
+               double scaling_value,
+               const SensorDataLinux::ReaderFunctor& apply_scaling_func);
 
   // Contains paths to sensor files that are set when
   // Create() is called.
   const std::vector<base::FilePath> sensor_paths_;
 
+  // Scaling values that are applied to raw data from sensors.
+  const double scaling_value_;
+
+  // Used to apply scalings and invert signs if needed.
+  const SensorDataLinux::ReaderFunctor apply_scaling_func_;
+
   DISALLOW_COPY_AND_ASSIGN(SensorReader);
 };
 
 }  // namespace device
 
 #endif  // DEVICE_GENERIC_SENSOR_LINUX_PLATFORM_SENSOR_UTILS_LINUX_H_