Cubietruck---16.设备的添加及数据分析

一. 新发现设备的处理流程
当设备第一次插入时或者在扫描/dev/input/event*时,
inputreader会收到event

1. void InputReader::loopOnce() 
   
2. {
3.     //获取event
   
4.     size_t count = mEventHub->getEvents(timeoutMillis, mEventBuffer, EVENT_BUFFER_SIZE);
   
5.     if (count) {
   
6.         processEventsLocked(mEventBuffer, count); //对event进行处理
   
7.     }
   
8.     mQueuedListener->flush();
   
9. }

InputReader::loopOnce
  --> InputReader::processEventsLocked

1. void InputReader::processEventsLocked(const RawEvent* rawEvents, size_t count) 
   
2. { 
   
3.     for (const RawEvent* rawEvent = rawEvents; count;) 
   
4.     {
   
5.         if (type < EventHubInterface::FIRST_SYNTHETIC_EVENT) {
   
6.             //数据处理流程
   
7.         } else {
   
8.             switch (rawEvent->type) {
   
9.                 case EventHubInterface::DEVICE_ADDED: //新发现的设备的处理
   
10.                     addDeviceLocked(rawEvent->when, rawEvent->deviceId); 
    
11.                     break;
    
12.                 case EventHubInterface::DEVICE_REMOVED: 
    
13.                     removeDeviceLocked(rawEvent->when, rawEvent->deviceId); 
    
14.                     break; 
    
15.                 case EventHubInterface::FINISHED_DEVICE_SCAN:  //最后会调用这个
    
16.                     handleConfigurationChangedLocked(rawEvent->when); 
    
17.                     break;
    
18.                 default: 
    
19.                     ALOG_ASSERT(false); // can't happen 
    
20.                     break; 
    
21.             } 
    
22.         } 
    
23.     }
    
24. }

InputReader::loopOnce
  --> InputReader::processEventsLocked
       --> InputReader::addDeviceLocked

1. void InputReader::addDeviceLocked(nsecs_t when, int32_t deviceId) 
   
2. {
   
3.     ssize_t deviceIndex = mDevices.indexOfKey(deviceId);
   
4.     InputDeviceIdentifier identifier = mEventHub->getDeviceIdentifier(deviceId);
   
5.     uint32_t classes = mEventHub->getDeviceClasses(deviceId);
   
6. 
   
7.     InputDevice* device = createDeviceLocked(deviceId, identifier, classes);
   
8.     device->configure(when, &mConfig, 0);
   
9.     device->reset(when);
   
10.     mDevices.add(deviceId, device);
    
11.     bumpGenerationLocked();
    
12. }