[sensors] Ambient light sensor implementation for ChromeOS and Linux.

device/generic_sensor/platform_sensor_ambient_light_iio.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_PLATFORM_SENSOR_AMBIENT_LIGHT_SENSOR_IIO_H_
+#define DEVICE_GENERIC_SENSOR_PLATFORM_SENSOR_AMBIENT_LIGHT_SENSOR_IIO_H_
+
+#include "base/memory/ref_counted.h"
+#include "device/generic_sensor/ambient_light_reader_iio.h"
+#include "device/generic_sensor/polling_platform_sensor.h"
+
+namespace device {
+
+class PlatformSensorAmbientLightIio : public PollingPlatformSensor {
+ public:
+  // Factory method.
+  static scoped_refptr<PlatformSensor> CreateSensor(
+      mojom::SensorType type,
+      mojo::ScopedSharedBufferMapping mapping,
+      uint64_t buffer_size,
+      PlatformSensorProvider* provider,
+      scoped_refptr<base::SingleThreadTaskRunner> task_runner);
+
+  // PollingPlatformSensor implements:
+  void UpdateReading() override;
+
+  // PlatformSensor implements:
+  mojom::ReportingMode GetReportingMode() override;
+
+  bool sensor_exists() const { return sensor_exists_; }
+
+ protected:
+  // PlatformSensor implements:
+  ~PlatformSensorAmbientLightIio() override;
+  bool CheckSensorConfiguration(
+      const PlatformSensorConfiguration& configuration) override;
+  PlatformSensorConfiguration GetDefaultConfiguration() override;
+
+ private:
+  PlatformSensorAmbientLightIio(
+      mojom::SensorType type,
+      mojo::ScopedSharedBufferMapping mapping,
+      uint64_t buffer_size,
+      PlatformSensorProvider* provider,
+      scoped_refptr<base::SingleThreadTaskRunner> task_runner);
+
+  double lux_value_;
+  bool sensor_exists_;
+  std::unique_ptr<AmbientLightSensorReaderIio> ambient_light_reader_;
+  base::WeakPtrFactory<PlatformSensorAmbientLightIio> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(PlatformSensorAmbientLightIio);
+};
+
+}  // namespace device
+
+#endif  // DEVICE_GENERIC_SENSOR_PLATFORM_SENSOR_AMBIENT_LIGHT_SENSOR_IIO_H_