drivers/iic/iic.c

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#include "includes.h"

#define DELAYTIME 1000
#define TIMEOUT (15625*10)
#define IICBUFSIZE 0x20
enum {WRDATA=1,POLLACK,RDDATA,SETRDADDR};
void F_IicInit(void);
void F_IicWrite(U32 slvAddr,U32 addr,U8 data);
void F_IicRead(U32 slvAddr,U32 addr,U8 *data);
void F_IicPollingSet(void);
void F_IicPolling(void);

static U8 _iicData[IICBUFSIZE];
static volatile int _iicDataCount;
static volatile int _iicStatus;
static volatile int _iicMode;
static int _iicPt;

void F_IicInit(void){
    rGPEUP  |= 0xc000;                  //Pull-up disable
    rGPECON = (rGPECON&~0xf0000000) | 0xa0000000;                //GPE15:IICSDA , GPE14:IICSCL 
    //Enable ACK, Prescaler IICCLK=PCLK/16, Enable interrupt, Transmit clock value Tx
    //clock=IICCLK/16
    //IICCON = 0xaf;  /* PCLK/512 */
    rIICCON  = (1<<7) | (0<<6) | (1<<5) | (0xf);
    rIICADD  = 0x10;                    //2440 slave address = [7:1]
    rIICSTAT = 0x10;                    //IIC bus data output enable(Rx/Tx)
    //rIICADD = 0x9f;
    //rIICSTAT = 0x9f;
}
void F_IicDelay(U32 i){
    if(i==0) for(i=0;i<10000;i++);
    else if(i==1) for(i=0;i<1000;i++);
    else if(i==2) for(i=0;i<100;i++);
}
void F_IicWrite(U32 slvAddr,U32 addr,U8 data){
    ulong timeout;

    _iicMode      = WRDATA;
    _iicPt        = 0;
    _iicData[0]   = (U8)addr;
    _iicData[1]   = data;
    _iicDataCount = 2;
    rIICDS        = slvAddr;            //0xa0
    rIICSTAT      = 0xf0;
    timeout = 0x100000;
    while(_iicDataCount!=-1) {
       F_IicPollingSet();
       if(timeout!=0) timeout--;
       if (timeout==0) break;
    }
    rIICSTAT = 0xd0;                    //Master Tx condition, Stop(Write), Output Enable
    rIICCON  = 0xaf;                    //Resumes IIC operation.
    F_IicDelay(0);                           //Wait until stop condtion is in effect.
}

void F_IicRead(U32 slvAddr,U32 addr,U8 *data)
{
    ulong timeout;
    
    _iicMode      = SETRDADDR;
    _iicPt        = 0;
    _iicData[0]   = (U8)addr;
    _iicDataCount = 1;

    rIICDS   = slvAddr;
    rIICSTAT = 0xf0;                    //MasTx,Start  
    //rIICCON  = 0xaf;
    //Clearing the pending bit isn't needed because the pending bit has been cleared.
    timeout = 0x100000;
    while(_iicDataCount!=-1) {
       F_IicPollingSet();
       if(timeout!=0) timeout--;
       if (timeout==0) break;
    }
    _iicMode      = RDDATA;
    _iicPt        = 0;
    _iicDataCount = 1;
    rIICDS   = slvAddr;
    rIICSTAT = 0xb0;                    //Master Rx,Start
    rIICCON  = 0xaf;                    //Resumes IIC operation.   
    timeout = 0x100000;
    while(_iicDataCount!=-1) {
       F_IicPollingSet();
       if(timeout!=0) timeout--;
       if (timeout==0) break;
    }
    *data = _iicData[1];
    F_IicDelay(0);
}

void F_IicPollingSet(void)
{
    if(rIICCON & 0x10) {                  //Tx/Rx Interrupt Enable
       F_IicPolling();
    }
}       
    
void F_IicPolling(void)
{
    U32 iicSt,i;
    
    iicSt = rIICSTAT; 
    if(iicSt & 0x8){}                   //When bus arbitration is failed.
    if(iicSt & 0x4){}                   //When a slave address is matched with IICADD
    if(iicSt & 0x2){}                   //When a slave address is 0000000b
    if(iicSt & 0x1){}                   //When ACK isn't received
    //_iicStatus = iicSt;

    //printk(">");
    switch(_iicMode)
    {
        case POLLACK:
            _iicStatus = iicSt;
            break;

        case RDDATA:
            if((_iicDataCount--)==0)
            {
                _iicData[_iicPt++] = rIICDS;
            
                rIICSTAT = 0x90;                //Stop MasRx condition 
                rIICCON  = 0xaf;                //Resumes IIC operation.
                //while (rIICSTAT & 0x20);
                
                F_IicDelay(1);                       //Wait until stop condtion is in effect.
                                                 //Too long time... 
                                                //The pending bit will not be set after issuing stop condition.
                break;    
            }      
            _iicData[_iicPt++] = rIICDS;
                        //The last data has to be read with no ack.
            if((_iicDataCount)==0)
                rIICCON = 0x2f;                 //Resumes IIC operation with NOACK.  
            else 
                rIICCON = 0xaf;                 //Resumes IIC operation with ACK
            break;

        case WRDATA:
            if((_iicDataCount--)==0)
            {
                rIICSTAT = 0xd0;                //stop MasTx condition 
                rIICCON  = 0xaf;                //resumes IIC operation.
                //while (rIICSTAT & 0x20);
                F_IicDelay(1);                       //wait until stop condtion is in effect.
                       //The pending bit will not be set after issuing stop condition.
                break;    
            }
            rIICDS = _iicData[_iicPt++];        //_iicData[0] has dummy.
            for(i=0;i<100;i++);                  //for setup time until rising edge of IICSCL
            rIICCON = 0xaf;                     //resumes IIC operation.
            break;

        case SETRDADDR:
//          Uart_Printf("[S%d]",_iicDataCount);
            if((_iicDataCount--)==0)
            {
                F_IicDelay(1);
                break;                  //IIC operation is stopped because of IICCON[4]    
            }
            rIICDS = _iicData[_iicPt++];
            for(i=0;i<100;i++);          //for setup time until rising edge of IICSCL
            rIICCON = 0xaf;             //resumes IIC operation.
            break;

        default:
            break;
    }
}

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