1 /* 2 * Copyright (C) 2011 Samsung 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include <fcntl.h> 18 #include <errno.h> 19 #include <math.h> 20 #include <poll.h> 21 #include <unistd.h> 22 #include <dirent.h> 23 #include <sys/select.h> 24 #include <cutils/log.h> 25 #include <pthread.h> 26 27 #include "LightSensor.h" 28 LightSensor()29LightSensor::LightSensor() 30 : SamsungSensorBase(NULL, "lightsensor-level", ABS_MISC) 31 { 32 mPendingEvent.sensor = ID_L; 33 mPendingEvent.type = SENSOR_TYPE_LIGHT; 34 } 35 handleEvent(input_event const * event)36bool LightSensor::handleEvent(input_event const *event) { 37 if (event->value == -1) { 38 return false; 39 } 40 // Convert adc value to lux assuming: 41 // I = 10 * log(Ev) uA 42 // R = 24kOhm 43 // Max adc value 1023 = 1.25V 44 // 1/4 of light reaches sensor 45 mPendingEvent.light = powf(10, event->value * (125.0f / 1023.0f / 24.0f)) * 4; 46 return true; 47 } 48