davincievm_i2c.c

开发环境CCS3.2,为TI最新处理器TMS320DM6446的网卡驱动程序源码

/*
 *  Copyright 2005 by Spectrum Digital Incorporated.
 *  All rights reserved. Property of Spectrum Digital Incorporated.
 *
 *  Not for distribution.
 */

/*
 *  I2C implementation
 *
 */

#include "davincievm_i2c.h"

/* ------------------------------------------------------------------------ *
 *                                                                          *
 *  DAVINCIEVM_I2C_init( )                                                  *
 *                                                                          *
 *      Enable and initalize the I2C module                                 *
 *                                                                          *
 *      The I2C clk is set to run at 20 KHz                                 *
 *                                                                          *
 * ------------------------------------------------------------------------ */
Int16 DAVINCIEVM_I2C_init( )
{
    I2C_ICMDR   = 0;                    // Reset I2C
    I2C_ICPSC   = 26;                   // Config prescaler for 27MHz
    I2C_ICCLKL  = 5;                    // Config clk LOW for 50kHz
    I2C_ICCLKH  = 5;                    // Config clk HIGH for 50kHz
    I2C_ICMDR  |= ICMDR_IRS;            // Release I2C from reset
    return 0;
}

/* ------------------------------------------------------------------------ *
 *                                                                          *
 *  DAVINCIEVM_I2C_close( )                                                 *
 *                                                                          *
 * ------------------------------------------------------------------------ */
Int16 DAVINCIEVM_I2C_close( )
{
    I2C_ICMDR = 0;                      // Reset I2C
    return 0;
}

/* ------------------------------------------------------------------------ *
 *                                                                          *
 *  DAVINCIEVM_I2C_reset( )                                                 *
 *                                                                          *
 *                                                                          *
 *                                                                          *
 * ------------------------------------------------------------------------ */
Int16 DAVINCIEVM_I2C_reset( )
{
    DAVINCIEVM_I2C_close( );
    DAVINCIEVM_I2C_init( );
    return 0;
}

/* ------------------------------------------------------------------------ *
 *                                                                          *
 *  DAVINCIEVM_I2C_write( i2caddr, data, len )                              *
 *                                                                          *
 *      I2C write in Master mode                                            *
 *                                                                          *
 *      i2caddr <- I2C slave address                                        *
 *      data    <- I2C data ptr                                             *
 *      len     <- # of bytes to write                                      *
 *                                                                          *
 * ------------------------------------------------------------------------ */
Int16 DAVINCIEVM_I2C_write( Uint16 i2caddr, Uint8* data, Uint16 len )
{
    Uint16 i;
    Int32 timeout   = 0x20000;
    Int32 timecount = 0;

    I2C_ICCNT = len;                    // Set len
    I2C_ICSAR = i2caddr;                // Set I2C slave address
    I2C_ICMDR = ICMDR_STT               // Config for master write
              | ICMDR_TRX
              | ICMDR_MST
              | ICMDR_IRS
              | ICMDR_FREE
              ;

    DAVINCIEVM_wait( 10 );              // Short delay

    for ( i = 0 ; i < len ; i++ )
    {
        I2C_ICDXR = data[i];            // Write

        timecount = 0;
        do
        {
            timecount++;
            if ( timecount >= timeout )
            {
                DAVINCIEVM_I2C_reset( );
                return 1000;
            }
        } while ( ( I2C_ICSTR & ICSTR_ICXRDY ) == 0 );// Wait for Tx Ready
    }

    I2C_ICMDR |= ICMDR_STP;             // Generate STOP
    return 0;
}

/* ------------------------------------------------------------------------ *
 *                                                                          *
 *  DAVINCIEVM_I2C_read( i2caddr, data, len )                               *
 *                                                                          *
 *      I2C read in Master mode                                             *
 *                                                                          *
 *      i2caddr <- I2C slave address                                        *
 *      data    <- I2C data ptr                                             *
 *      len     <- # of bytes to write                                      *
 *                                                                          *
 * ------------------------------------------------------------------------ */
Int16 DAVINCIEVM_I2C_read( Uint16 i2caddr, Uint8* data, Uint16 len )
{
    Uint16 i;
    Int32 timeout   = 0x20000;
    Int32 timecount = 0;

    I2C_ICCNT = len;                    // Set len
    I2C_ICSAR = i2caddr;                // Set I2C slave address
    I2C_ICMDR = ICMDR_STT               // Config for master read
              | ICMDR_MST
              | ICMDR_IRS
              | ICMDR_FREE
              ;

    for ( i = 0 ; i < len ; i++ )
    {
        timecount = 0;
        do
        {
            timecount++;
            if ( timecount >= timeout )
            {
                DAVINCIEVM_I2C_reset( );
                return 1000;
            }
        } while ( ( I2C_ICSTR & ICSTR_ICRRDY ) == 0 );// Wait for Rx Ready
        data[i] = I2C_ICDRR;            // Read
    }

    I2C_ICMDR |= ICMDR_STP;             // Generate STOP
    return 0;
}