wince5.0 2440 BSP之摄像头驱动分析

现在看驱动就看那几个接口函数即可，现在先看初始化函数。

3. DWORD CIS_Init(DWORD dwContext)
4. {
5.     DWORD dwErr = ERROR_SUCCESS, bytes;
7.     RETAILMSG(MSG_EN_1, (TEXT("CIS::CIS_Init() /r/n")));
9. // Allocate for our main data structure and one of it's fields.
10.     pCIS = (PCIS_CONTEXT)LocalAlloc( LPTR, sizeof(CIS_CONTEXT) );
11.     if ( !pCIS )
12.         return( NULL );
13.     
14.     pCIS->Sig = CIS_SIG;    
16.     // 1. Virtual Alloc
17.     Virtual_Alloc();
19.     RETAILMSG(MSG_EN_1, (TEXT("CIS::Virtual_Alloc /r/n"))); 
21.     //RETAILMSG(1, (TEXT("CIS_Init : IOCTL_HAL_REQUEST_SYSINTR /r/n")));
22. //这里动态申请Camera接口的中断
23.     if (!KernelIoControl(IOCTL_HAL_REQUEST_SYSINTR, &g_CamIrq, sizeof(UINT32), &g_CamSysIntr, sizeof(UINT32), NULL))
24.     {
25.         RETAILMSG(1, (TEXT("ERROR: CIS_INIT: Failed to request sysintr value for Camera interrupt./r/n")));
26.         return(0);
27.     }
28.     
29.     InitializeCriticalSection(&pCIS->RegCS);
30. //MSG_EN_1控制是否打印，这里MSG_EN_1是0故没有打印出来
31.     RETAILMSG(MSG_EN_1, (TEXT("CIS::InitializeCriticalSection /r/n")));
33.     //
34.     // Init I2C
35.     //这里让我大开眼界，在驱动中调用另外一个驱动，并且方法完全和应用程序相同
36.     pCIS->hI2C = CreateFile( L"I2C0:",
37.                              GENERIC_READ|GENERIC_WRITE,
38.                              FILE_SHARE_READ|FILE_SHARE_WRITE,
39.                              NULL, OPEN_EXISTING, 0, 0);
40.                    
41.     if ( INVALID_HANDLE_VALUE == pCIS->hI2C ) {
42.         dwErr = GetLastError();//这个查错函数也比较有意思
43.         //DEBUGMSG(ZONE_ERR, (TEXT("Error %d opening device '%s' /r/n"), dwErr, L"I2C0:" ));
44.         RETAILMSG(I2C_MSG, (TEXT("Error %d opening device '%s' /r/n"), dwErr, L"I2C0:" ));
45.         goto _error_exit;
46.     }
48.     RETAILMSG(MSG_EN_1, (TEXT("CIS::CreateFile(/"I2C0/") /r/n")));
50.     //memset((void*)pCIS->eg, 0, sizeof(pCIS->eg));
52.     //
53.     // Gat Fastcall driver-to-driver entrypoints
54.     //
55.     if ( !DeviceIoControl(pCIS->hI2C,
56.                           IOCTL_I2C_GET_FASTCALL, //IOCTL_I2C_GET_FASTCALL是在IIC驱动里面的
57.                           NULL, 0, 
58.                           &pCIS->fc, sizeof(pCIS->fc),
59.                           &bytes, NULL) ) 
60.     {
61.         dwErr = GetLastError();
62.         DEBUGMSG(ZONE_ERR,(TEXT("IOCTL_I2C_GET_FASTCALL ERROR: %u /r/n"), dwErr));
63.         goto _error_exit;
64.     }            
66.     RETAILMSG(MSG_EN_1, (TEXT("CIS::DeviceIoControl /r/n")));
68.     // Init H/W
69.     pCIS->State = INITIALIZE;
71.     Cam_Init();//这是摄像头读取注册表的一些信息，并初始化，我现在暂时不看这部分。
73.     if (!InitInterruptThread())//这个用来初始化Camera中断线程
74.     {
75.         RETAILMSG(1,(TEXT("Fail to initialize camera interrupt event/r/n")));
76.         return FALSE;
77.     }    
79.     pCIS->Dx = D0;
81.     m_Dx = (_CEDEVICE_POWER_STATE)D0;
82.     DevicePowerNotify(_T("CIS1:"),(_CEDEVICE_POWER_STATE)D0, POWER_NAME);
84.     mInitialized = TRUE;
85.     return TRUE;
87. _error_exit:
88.     return dwErr;   
89. }

DeviceIoControl到底是怎么和驱动联系起来的呢？

我发现在IIC驱动中有如下代码

// OUT: PI2C_FASTCALL
#define IOCTL_I2C_GET_FASTCALL  /
    CTL_CODE(FILE_DEVICE_I2C, 2, METHOD_BUFFERED, FILE_ANY_ACCESS)

 

还有，在I2C_IOControl中有

case IOCTL_I2C_GET_FASTCALL:
            if ( (dwLenOut < sizeof(I2C_FASTCALL)) || !pBufOut ) {
                bRc = FALSE;
                dwErr = ERROR_INVALID_PARAMETER;
                break;
            }

现在来看看CTL_CODE(FILE_DEVICE_I2C, 2, METHOD_BUFFERED, FILE_ANY_ACCESS)到底是什么意思

这个是个微软的函数

This macro creates a unique system I/O control code (IOCTL).

#define CTL_CODE(, , , ) (
  (() << 16) | (() << 14) | (() << 2) | ()
)

现在暂时不理会先。继续往下看。

InitInterruptThread

2. //这个是5.0动态中断线程，见过很多了，就不注释了。
4. BOOL InitInterruptThread()
5. {
6.     DWORD         threadID;                         // thread ID
7.     BOOL bSuccess;
9.     CameraEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
10.     
11.     if (!CameraEvent)
12.     {
13.         return FALSE;
14.     }
16.     bSuccess = InterruptInitialize(g_CamSysIntr, CameraEvent, NULL, 0);
17.     if (!bSuccess) 
18.     {
19.         RETAILMSG(1,(TEXT("Fail to initialize camera interrupt event/r/n")));
20.         return FALSE;
21.     }    
22.     
23.     CameraThread = CreateThread(NULL,
24.                                  0,
25.                                  (LPTHREAD_START_ROUTINE)CameraCaptureThread,
26.                                  0,
27.                                  0,
28.                                  &threadID);
29.     
30.     if (NULL == CameraThread ) {
31.         RETAILMSG(1,(TEXT("Create Camera Thread Fail/r/n")));
32.     }
33.     
34.     RETAILMSG(1,(_T("CAMERA.DLL::InterruptThread Initialized./r/n")));
35.     return TRUE;
36. }

再往下看

CameraCaptureThread

3. DWORD CameraCaptureThread(void)
4. {
5.     unsigned char tmp=0;
6.     static unsigned int time,old_time;
7.     static unsigned int cam_intr;
8.     
9.     DWORD   dwCause;                    // LJY PWR040613
11.     //dwDisplayTimeout = INFINITE;
13.     SetProcPermissions((DWORD)-1);
14.     
15.     while(TRUE)
16.     {
17.         RETAILMSG(0,(TEXT("[CAM_HW] InterruptThread : Waiting For a Single Object/n/r")));
18.         //一般查询dwDisplayTimeout是一个时间常数，中断是INFINITE，在这里是个
19.         dwCause = WaitForSingleObject(CameraEvent, dwDisplayTimeout);
20.         
21.         RETAILMSG(MSG_EN_1,(_T("CameraCaptureThread(%d)++/r/n"), frame_count));
23. #if 0
24.         if (frame_count <= 2) {
25.             //frame_count++;
26.             // Enable camera interrupt
27.             s2440INT->INTSUBMSK &= ~(( 1 << IRQ_SUB_CAM_P )|( 1 << IRQ_SUB_CAM_C ));
28.             s2440INT->INTMSK &= ~( 1 << IRQ_CAM );
29.             
30.             continue;
31.         }
32. #endif
33.         
34.         if (dwCause == WAIT_OBJECT_0) // LJY PWR
35.         {
36.             Lock();
38.             __try
39.             {
41.                 if (s2440INT->INTSUBMSK & ( 1 << IRQ_SUB_CAM_C ))
42.                 {
43.                     frame_count++;
44.                     cam_intr |= ( 1 << IRQ_SUB_CAM_C );
45.                     
46.                     s2440INT->SUBSRCPND  =  (1<<IRQ_SUB_CAM_C);
47.                     s2440INT->INTSUBMSK &= ~(1<<IRQ_SUB_CAM_C);
48.                     //RETAILMSG(1,(_T("CAM_C, ts %d/r/n"), GetTickCount()));
49.                 }
51.                 if (s2440INT->INTSUBMSK & ( 1 << IRQ_SUB_CAM_P ))
52.                 {
53.                     cam_intr |= ( 1 << IRQ_SUB_CAM_P );
54.                     
55.                     s2440INT->SUBSRCPND  =  (1<<IRQ_SUB_CAM_P);
56.                     s2440INT->INTSUBMSK &= ~(1<<IRQ_SUB_CAM_P);
57.                     //RETAILMSG(1,(_T("CAM_P, ts %d/r/n"), GetTickCount()));
58.                 }
60.                 if (((s2440INT->INTSUBMSK & ( 1 << IRQ_SUB_CAM_C )) == 0) && ((s2440INT->INTSUBMSK & ( 1 << IRQ_SUB_CAM_P )) == 0))
61.                 {
62.                     RETAILMSG(MSG_EN_1,(_T("[CAM]NOP/r/n")));                   
63.                 }
64.                 
65.                 
66.                 InterruptDone(g_CamSysIntr);                
67.             
68.                 //time = GetTickCount();
69.                 //RETAILMSG(1,(TEXT("+time:%d/r/n"),(time - old_time)));
70.     
71.                 // Handle any interrupts on the input source
72.                 if (cam_intr & ( 1 << IRQ_SUB_CAM_P ))
73.                 {
74.                     // display the image    
75.                     if (DRIVER_PREVIEW_ENABLE == 1)
76.                     Display_Cam_Image(0,0,PREVIEW_X, PREVIEW_Y, PORT_A);
78.                     Buffer_preview_info_update();
79.                     cam_intr &= ~( 1 << IRQ_SUB_CAM_P );
80.                 }
81.                     
82.                 if (cam_intr & ( 1 << IRQ_SUB_CAM_C ))
83.                 {
84.                     Buffer_codec_info_update();
85.                     cam_intr &= ~( 1 << IRQ_SUB_CAM_C );
86.                 }
88.                 // Enable camera interrupt
89.                 //s2440INT->INTSUBMSK &= ~(( 1 << IRQ_SUB_CAM_P )|( 1 << IRQ_SUB_CAM_C ));
90.                 //s2440INT->INTMSK &= ~( 1 << IRQ_CAM );
92.                 //old_time = GetTickCount();
93.                 //RETAILMSG(1,(TEXT("-time:%d/r/n"),(old_time-time)));
95.             }
96.             __except(EXCEPTION_EXECUTE_HANDLER)
97.             {
98.                 RETAILMSG(PM_MSG, (TEXT("Camera.DLL:InterruptThread() - EXCEPTION: %d"), GetExceptionCode()));
99.             }
100.                 
101.             Unlock();
102.             
103.         }
104.         else if (dwCause == WAIT_TIMEOUT)
105.         {
106.             Lock();
107.             
108.             RETAILMSG(PM_MSG,(_T("[CAM_HW] InterruptThread Timeout : %d msec/r/n"), dwDisplayTimeout));
109.             
110.             dwDisplayTimeout = INFINITE;                // reset timeout until Camera Interrupt occurs
111.             bIdlePwrDown = TRUE;                    // Codec is off
113.             CamInterface_PowerDown();
114.             RETAILMSG(PM_MSG, (TEXT("[CAM_HW] InterruptThread : bIdlePwrDown = TRUE/r/n")));
116.             Unlock();
117.         }
118.         else
119.         {
120.             RETAILMSG(PM_MSG, (TEXT("[CAM_HW] InterruptThread : Exit %d, Cause %d/r/n"), GetLastError(), dwCause));
121.         }
122.     }
124.     return 0;
125. }

我看上去觉得一开机就会产生这个摄像头扑捉线程，我觉得不合理，串口打印信息也没有打印出来，应该没有被调用。到底在哪里控制这些程序的调用呢？