wince下Gpio 驱动程序

Gpio 驱动程序

  在WINCE下能够直接访问的都是虚拟地址，不能直接访问GPIO端口，因此我们首先需要将GPIO口的物理地址映射到虚拟地址上来。

   分别使用VirtualAlloc和VirtualCopy这两个函数来完成映射！

这两个函数的原型：

LPVOID VirtualAlloc(     LPVOID lpAddress,       DWORD dwSize,

DWORD flAllocationType,   DWORD flProtect );

BOOL VirtualCopy( LPVOID lpvDest, LPVOID lpvSrc, DWORD cbSize, DWORD fdwProtect );

如果这两个函数执行成功，哪么VirtualAlloc将返回一个指针，使用这个指针我们就可以直接访问GPIO，通过读写相关地址寄存器，来控制GPIO端口！

  v_pIOPregs = (volatile IOPreg *)VirtualAlloc(0, sizeof(IOPreg), MEM_RESERVE, PAGE_NOACCESS);

         if (v_pIOPregs == NULL){

                   RetValue = FALSE;

         }

         else {

                   if (!VirtualCopy((PVOID)v_pIOPregs, (PVOID)(IOP_BASE), sizeof(IOPreg), PAGE_READWRITE | PAGE_NOCACHE)) {

                            RetValue = FALSE;

                   }

         }

         if (!RetValue){

                   //PIO_InitializeAddresses - Failed !!

         if (v_pIOPregs){

                            VirtualFree((PVOID) v_pIOPregs, 0, MEM_RELEASE);

                   }

                   v_pIOPregs = NULL;

         }

         //else RETAILMSG (1, (TEXT("::: PBT_InitializeAddresses - Success\r\n") ));

         return(RetValue);

v_pIOPregs是一个IOPreg结构，在s2410.h中定义，

//

// Registers : I/O port

#define IOP_BASE      0xB1600000 // 0x56000000

typedef struct  {

    unsigned int  rGPACON;                  // 00

    unsigned int  rGPADAT;

    unsigned int  rPAD1[2];

   

    unsigned int  rGPBCON;                  // 10

    unsigned int  rGPBDAT;

    unsigned int  rGPBUP;

    unsigned int  rPAD2;

   

    unsigned int  rGPCCON;                  // 20

    unsigned int  rGPCDAT;

    unsigned int  rGPCUP;

    unsigned int  rPAD3;

   

    unsigned int  rGPDCON;                  // 30

    unsigned int  rGPDDAT;

    unsigned int  rGPDUP;

    unsigned int  rPAD4;

   

    unsigned int  rGPECON;                  // 40

    unsigned int  rGPEDAT;

    unsigned int  rGPEUP;

    unsigned int  rPAD5;

   

    unsigned int  rGPFCON;                   // 50

    unsigned int  rGPFDAT;

    unsigned int  rGPFUP;

    unsigned int  rPAD6;

   

    unsigned int  rGPGCON;                  // 60

    unsigned int  rGPGDAT;

    unsigned int  rGPGUP;

    unsigned int  rPAD7;

   

    unsigned int  rGPHCON;                  // 70

    unsigned int  rGPHDAT;

    unsigned int  rGPHUP;

    unsigned int  rPAD8;

   

    unsigned int  rMISCCR;          // 80

    unsigned int  rDCKCON;                 

    unsigned int  rEXTINT0;

    unsigned int  rEXTINT1;                  

    unsigned int  rEXTINT2;                   // 90

         unsigned int  rEINTFLT0;

         unsigned int  rEINTFLT1;

         unsigned int  rEINTFLT2;

         unsigned int  rEINTFLT3;                 // A0

         unsigned int  rEINTMASK;

         unsigned int  rEINTPEND;

         unsigned int  rGSTATUS0;

         unsigned int  rGSTATUS1;                // B0

}IOPreg;