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      1 /*
      2  * Copyright 2013 The Android Open Source Project
      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 
     26 #include "sensors.h"
     27 #include "LightSensor.h"
     28 
     29 #define ABS_LIGHT   0x29
     30 
     31 LightSensor::LightSensor()
     32     : SensorBase(NULL, LIGHT_DATA),
     33       mEnabled(0),
     34       mEventsSinceEnable(0),
     35       mInputReader(4),
     36       mHasPendingEvent(false)
     37 {
     38     mPendingEvent.sensor = ID_L;
     39     mPendingEvent.type = SENSOR_TYPE_LIGHT;
     40     memset(mPendingEvent.data, 0, sizeof(mPendingEvent.data));
     41 }
     42 
     43 LightSensor::~LightSensor()
     44 {
     45 }
     46 
     47 int LightSensor::setInitialState()
     48 {
     49     return 0;
     50 }
     51 
     52 int LightSensor::setDelay(int32_t handle, int64_t ns)
     53 {
     54     int fd;
     55     char sysfs[PATH_MAX];
     56 
     57     strcpy(sysfs, I2C);
     58     strcat(sysfs, "als_poll_delay");
     59 
     60     fd = open(sysfs, O_RDWR);
     61     if (fd >= 0) {
     62         char buf[16] = {0,};
     63         snprintf(buf, sizeof(buf), "%lld", ns);
     64         write(fd, buf, sizeof(buf));
     65         close(fd);
     66         return 0;
     67     }
     68     return -1;
     69 }
     70 
     71 int LightSensor::enable(int32_t handle, int en)
     72 {
     73     int newState = en ? 1 : 0;
     74     int err = 0;
     75 
     76     if (newState != mEnabled) {
     77         if (!mEnabled && dev_name != NULL) {
     78             open_device();
     79         }
     80 
     81         char sysfs[PATH_MAX];
     82 
     83         strcpy(sysfs, I2C);
     84         strcat(sysfs, "enable_als_sensor");
     85 
     86         ALOGI_IF(DEBUG, "enable.open(%s), en(%d)", sysfs, en);
     87 
     88         int fd = open(sysfs, O_RDWR);
     89         if (fd < 0) {
     90             ALOGE("couldn't open '%s' input device", sysfs);
     91             err = -1;
     92         } else {
     93             char buf[2];
     94 
     95             buf[0] = newState ? '1' : '0';
     96             buf[1] = '\0';
     97 
     98             write(fd, buf, sizeof(buf));
     99             close(fd);
    100             setInitialState();
    101         }
    102 
    103         mEnabled = newState;
    104 
    105         if (!mEnabled && dev_name != NULL) {
    106             close_device();
    107         }
    108     }
    109     return err;
    110 }
    111 
    112 bool LightSensor::hasPendingEvents() const
    113 {
    114     return mHasPendingEvent;
    115 }
    116 
    117 int LightSensor::readEvents(sensors_event_t* data, int count)
    118 {
    119     if (count < 1)
    120         return -EINVAL;
    121 
    122     if (mHasPendingEvent) {
    123         mHasPendingEvent = false;
    124         mPendingEvent.timestamp = getTimestamp();
    125         *data = mPendingEvent;
    126         return mEnabled ? 1 : 0;
    127     }
    128 
    129     ssize_t n = mInputReader.fill(data_fd);
    130     if (n < 0)
    131         return n;
    132 
    133     int numEventReceived = 0;
    134     input_event const* event;
    135 
    136     while (count && mInputReader.readEvent(&event)) {
    137         int type = event->type;
    138         if (type == EV_ABS) {
    139             if (event->code == ABS_LIGHT) {
    140                 mPendingEvent.sensor = ID_L;
    141                 mPendingEvent.type = SENSOR_TYPE_LIGHT;
    142                 mPendingEvent.light = (float)event->value;
    143             }
    144         } else if (type == EV_SYN) {
    145             mPendingEvent.timestamp = timevalToNano(event->time);
    146             if (mEnabled && (mPendingEvent.light != mPreviousLight) ) {
    147                 *data++ = mPendingEvent;
    148                 count--;
    149                 numEventReceived++;
    150                 mPreviousLight = mPendingEvent.light;
    151             }
    152         } else {
    153             ALOGE("LightSensor: unknown event (type=%d, code=%d)",
    154                     type, event->code);
    155         }
    156         mInputReader.next();
    157     }
    158 
    159     return numEventReceived;
    160 }
    161 
    162 float LightSensor::indexToValue(size_t index) const
    163 {
    164     return 0.0;
    165 }
    166