Android: Sensor

http://developer.android.com/intl/zh-TW/reference/android/hardware/Sensor.html
http://developer.android.com/intl/zh-TW/reference/android/hardware/SensorManager.html

1. framework/base/core/jni/, JNI will get sensor module, this may be implement in vendor dir. hw_module_t, sensors_module_t is define in hardware/libhardware/include/hardware/
2. sensors_data_init->sensors_data_open, and then call into module's data_open
3. sensors_data_poll, just polling the data from module::poll