Writing of LED driver based on WINCE S3C2440

volatile IOPreg   *s2440IOP = (IOPreg *)IOP_BASE;
volatile INTreg   *s2440INT = (INTreg *)INT_BASE;

The simple understanding of these two statements is to make s2440IOP and IOP_BASE equivalent, and s2440INT and INT_BASE equivalent.

IOP_BASE and INT_BASE in the s244.h header file

#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;  // AC
  unsigned int  rGSTATUS1;  // B0
  unsigned int  rGSTATUS2;  // B4 ;;; SHL
  unsigned int  rGSTATUS3;  // B8
  unsigned int  rGSTATUS4;  // BC
 
  unsigned int  rFLTOUT;   // C0
  unsigned int  rDSC0;
  unsigned int  rDSC1;
  unsigned int  rMSLCON;

  unsigned int  rGPJCON;   // D0
  unsigned int  rGPJDAT;
  unsigned int  rGPJUP;
  unsigned int  rPAD9;
 
}IOPreg; 

#define INT_BASE      0xB0A00000 // 0x4A000000
typedef struct  {
    unsigned int  rSRCPND;
    unsigned int  rINTMOD;
    unsigned int  rINTMSK;
    unsigned int  rPRIORITY;
    unsigned int  rINTPND;
    unsigned int  rINTOFFSET;
    unsigned int  rSUBSRCPND;
    unsigned int  rINTSUBMSK;
}INTreg ;   

It can be seen that IOPreg and INTreg are two structures, and INT_BASE and IOP_BASE are two virtual addresses. Therefore, the above two statements strengthen the two virtual addresses into the first address of the structure, so that the registers corresponding to the structure can be accessed.