text: /*
   * Copyright (C) 2008 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #include <fcntl.h>
  #include <errno.h>
  #include <math.h>
  #include <poll.h>
  #include <unistd.h>
  #include <dirent.h>
  #include <sys/select.h>
  #include <cutils/log.h>
  #include <string.h>
  
  #include "CompassSensor.h"
  
  
  /*****************************************************************************/
  CompassSensor::CompassSensor()
      : SensorBase(NULL, "geomagnetic"),
        //mEnabled(0),
        mInputReader(4),
        mHasPendingEvent(false)
  {
      //ALOGD("CompassSensor::CompassSensor()");
      mPendingEvent.version = sizeof(sensors_event_t);
      mPendingEvent.sensor = ID_M;
      mPendingEvent.type = SENSOR_TYPE_MAGNETIC_FIELD;
      mPendingEvent.magnetic.status = SENSOR_STATUS_ACCURACY_HIGH;
      
      
      memset(mPendingEvent.data, 0, sizeof(mPendingEvent.data));
      
   //   ALOGD("CompassSensor::CompassSensor() open data_fd");
  	
      if (data_fd) {
          strcpy(input_sysfs_path, "/sys/class/input/");
          strcat(input_sysfs_path, input_name);
          strcat(input_sysfs_path, "/device/");
          input_sysfs_path_len = strlen(input_sysfs_path);
  
          //enable(0, 1);
      }
      
    //  ALOGE("MagneticSensor: sysfs: %s",input_sysfs_path);
  }
  
  CompassSensor::~CompassSensor() {
  
    //  ALOGD("CompassSensor::~CompassSensor()");
      if (mEnabled) {
          enable(0, 0);
      }
  }
  
  
  
  int CompassSensor::enable(int32_t, int en) {
  
  	   
     // ALOGD("CompassSensor::~enable(0, %d)", en);
      int flags = en ? 1 : 0;
      if (flags != mEnabled) {
          int fd;
          strcpy(&input_sysfs_path[input_sysfs_path_len], "enable");
          //ALOGD("CompassSensor::~enable(0, %d) open %s",en,  input_sysfs_path);
          fd = open(input_sysfs_path, O_RDWR);
          if (fd >= 0) {
              // ALOGD("CompassSensor::~enable(0, %d) opened %s",en,  input_sysfs_path);
              char buf[2];
              int err;
              buf[1] = 0;
              if (flags) {
                  buf[0] = '1';
              } else {
                  buf[0] = '0';
              }
              err = write(fd, buf, sizeof(buf));
              close(fd);
              mEnabled = flags;
              return 0;
          }
          return -1;        
      }
      return 0;
  }
  
  
  bool CompassSensor::hasPendingEvents() const {
      /* FIXME probably here should be returning mEnabled but instead
  	mHasPendingEvents. It does not work, so we cheat.*/
      //ALOGD("CompassSensor::~hasPendingEvents %d", mHasPendingEvent ? 1 : 0 );
      return mHasPendingEvent;
  }
  
  
  int CompassSensor::setDelay(int32_t handle, int64_t ns)
  {
      int fd;
      int val;
  
      // Kernel driver only support specific values
      if (ns < 20000000L) {
          val = 1;
      } else if (ns < 60000000L) {
          val = 20;
      } else if (ns < 200000000L) {
          val = 60;
      } else if (ns < 1000000000L) {
          val = 200;
      } else {
          val = 1000;
      }
  
   //   ALOGD("CompassSensor::~setDelay(%d, %lld) val = %d", handle, ns, val);
  
      strcpy(&input_sysfs_path[input_sysfs_path_len], "poll_delay");
      fd = open(input_sysfs_path, O_RDWR);
      if (fd >= 0) {
          char buf[80];
          sprintf(buf, "%d", val);
          write(fd, buf, strlen(buf)+1);
          close(fd);
          return 0;
      }
      return -1;
  }
  
  
  int CompassSensor::readEvents(sensors_event_t* data, int count)
  {
      //ALOGD("CompassSensor::~readEvents() %d", count);
      if (count < 1)
          return -EINVAL;
          
      if (mHasPendingEvent) {
          mHasPendingEvent = false;
          mPendingEvent.timestamp = getTimestamp();
          *data = mPendingEvent;
          return mEnabled ? 1 : 0;
      }
          
      ssize_t n = mInputReader.fill(data_fd);
      if (n < 0)
          return n;
  
      int numEventReceived = 0;
      input_event const* event;
  	
      while (count && mInputReader.readEvent(&event)) {
          int type = event->type;
          if (type == EV_ABS) {
              float value = event->value;
              if (event->code == EVENT_TYPE_MAGV_X) {
                  mPendingEvent.magnetic.x = (float)value / 20000.0f;
              } else if (event->code == EVENT_TYPE_MAGV_Y) {
                  mPendingEvent.magnetic.y = (float)value / 20000.0f;
              } else if (event->code == EVENT_TYPE_MAGV_Z) {
                  mPendingEvent.magnetic.z = (float)value / 20000.0f;
              }
          } else if (type == EV_SYN) {
              mPendingEvent.timestamp = timevalToNano(event->time);
              if (mEnabled) {
                  *data++ = mPendingEvent;
                  count--;
                  numEventReceived++;
              }
          } else {
              ALOGE("CompassSensor: unknown event (type=%d, code=%d)",
                      type, event->code);
          }
          mInputReader.next();
      }
   
  	//ALOGD("CompassSensor::~readEvents() numEventReceived = %d", numEventReceived);
  	return numEventReceived++;
  		
  }
  