bsp_i2c.c

嵌入式的tcpip协议栈

    VICIntEnable =  (1 << VIC_I2C0);                            /* Enable the interrupt source                              */
    OSSemPend(I2C_SemWait, 0, &err);                            /* Wait until complete                                      */

    OSSemPost(I2C_SemBusy);                                     /* Free I2C                                                 */
}

/*
*********************************************************************************************************
*                                        I2C_ReadReg()
*
* Description : Read a register on an I2C device.
*
* Argument(s) : p_buf       Pointer to the buffer into which the bytes will be stored.
*
*               count       Number of bytes to read.
*
*               reg         Register to read.
*
* Return(s)   : none.
*********************************************************************************************************
*/ 

void  I2C_ReadReg (CPU_INT08U  address,
                   CPU_INT08U  *p_buf,
                   CPU_INT08U   count,
                   CPU_INT08U   reg)
{
    CPU_INT08U  err;


    OSSemPend(I2C_SemBusy, 0, &err);                            /* Wait until I2C is free                                   */



    I20CONCLR    = I2CON_I2EN
                 | I2CON_STA
                 | I2CON_SI
                 | I2CON_AA;

    I20CONSET    = I2CON_I2EN;

    I2C_Address  = (address & 0xFE);                           /* Clear lower bit of address                               */
    I2C_BufPtr   = &reg;
    I2C_Count    = 1;

    I20CONSET    = I2CON_STA
                 | I2CON_AA;

    VICIntEnable =  (1 << VIC_I2C0);                            /* Enable the interrupt source                              */
    OSSemPend(I2C_SemWait, 0, &err);                            /* Wait until complete                                      */



    I20CONCLR    = I2CON_I2EN
                 | I2CON_STA
                 | I2CON_SI
                 | I2CON_AA;

    I20CONSET    = I2CON_I2EN;

    I2C_Address  = (address | 0x01);                    /* Set lower bit of address                                 */
    I2C_BufPtr   = p_buf;
    I2C_Count    = count;

    I20CONSET    = I2CON_STA
                 | I2CON_AA;


    VICIntEnable =  (1 << VIC_I2C0);                            /* Enable the interrupt source                              */
    OSSemPend(I2C_SemWait, 0, &err);                            /* Wait until complete                                      */


    OSSemPost(I2C_SemBusy);                                     /* Free I2C                                                 */
}

/*
*********************************************************************************************************
*                                        I2C_Write()
*
* Description : Write to the I2C bus.
*
* Argument(s) : p_buf       Pointer to the buffer storing the data to be written.
*
*               count       Number of bytes to write.
*
* Return(s)   : none.
*********************************************************************************************************
*/

void  I2C_Write (CPU_INT08U  address,CPU_INT08U *p_buf, CPU_INT08U count)
{
    CPU_INT08U  err;


    OSSemPend(I2C_SemBusy, 0, &err);                            /* Wait until I2C is free                                   */

    I20CONCLR    = I2CON_I2EN
                 | I2CON_STA
                 | I2CON_SI
                 | I2CON_AA;

    I20CONSET    = I2CON_I2EN;

    I2C_Address  = (address & 0xFE);                    /* Clear lower bit of address                               */
    I2C_BufPtr   = p_buf;
    I2C_Count    = count;

    I20CONSET    = I2CON_STA
                 | I2CON_AA;

    VICIntEnable =  (1 << VIC_I2C0);                            /* Enable the interrupt source                              */
    OSSemPend(I2C_SemWait, 0, &err);                            /* Wait until complete                                      */

    OSSemPost(I2C_SemBusy);                                     /* Free I2C                                                 */
}




/*
*********************************************************************************************************
*                                        I2C_ISR_Handler()
*
* Description : The I2C ISR handler.
*
* Argument(s) : none.
*
* Return(s)   : none.
*********************************************************************************************************
*/

void  I2C_ISR_Handler (void)
{
    CPU_INT32U  status;
    CPU_INT32U  temp;


    status = I20STAT;
    temp   = 0;

    switch (status & 0xF8) {

        case I2STAT_START:
        case I2STAT_REPEATED_START:
             I20DAT    = I2C_Address;
             I20CONCLR = I2CON_STA | I2CON_SI;
             break;

        case I2STAT_SLA_W_ACK:
             temp        = *I2C_BufPtr;
             I20DAT      = temp;
             I2C_BufPtr += 1;
             I2C_Count  -= 1;
             I20CONCLR   = I2CON_STA | I2CON_SI;
             break;

        case I2STAT_DAT_T_ACK:
             if (I2C_Count > 0) {
                 temp          = *I2C_BufPtr;
                 I20DAT        = temp;
                 I2C_BufPtr   += 1;
                 I2C_Count    -= 1;
                 I20CONCLR     = I2CON_STA | I2CON_SI;
             } else {
                 I20CONCLR     = I2CON_STA | I2CON_SI;
                 I20CONSET     = I2CON_STO;
                 OSSemPost(I2C_SemWait);
                 VICIntEnClear =  (1 << VIC_I2C0);
             }
             break;

        case I2STAT_SLA_W_NOACK:
        case I2STAT_DAT_T_NOACK:
        case I2STAT_SLA_R_NOACK:
             I20CONSET     = I2CON_STO;
             I20CONCLR     = I2CON_STA | I2CON_SI;
             OSSemPost(I2C_SemWait);
             VICIntEnClear =  (1 << VIC_I2C0);
             break;

        case I2STAT_ARB_LOST:
             I20CONCLR     = I2CON_STA | I2CON_SI;
             OSSemPost(I2C_SemWait);
             VICIntEnClear =  (1 << VIC_I2C0);
             break;


        case I2STAT_SLA_R_ACK:
             if (I2C_Count <= 1) {
                 I20CONSET = I2CON_AA;
             } else {
                 I20CONCLR = I2CON_AA;
             }
             I20CONCLR = I2CON_STA | I2CON_SI;
             break;

        case I2STAT_DAT_R_ACK:
             temp        = I20DAT;
            *I2C_BufPtr  = temp;
             I2C_BufPtr += 1;
             I2C_Count  -= 1;
             if (I2C_Count <= 1) {
                 I20CONCLR = I2CON_AA;
             }
             I20CONCLR   = I2CON_STA | I2CON_SI;
             break;

        case I2STAT_DAT_R_NOACK:
             temp          = I20DAT;
            *I2C_BufPtr    = temp;
             I2C_Count    -= 1;
             I20CONSET     = I2CON_STO;
             I20CONCLR     = I2CON_STA | I2CON_SI;
             OSSemPost(I2C_SemWait);
             VICIntEnClear =  (1 << VIC_I2C0);
             break;

        default:
             I20CONCLR = I2CON_STA | I2CON_SI;
             break;
    }
}