i2c.c

优龙YLP270开发板 光盘自带的BIOS和实验例程源码 强烈推荐

/******************************************************************************
**
**  COPYRIGHT (C) 2000, 2001 Intel Corporation.
**
**  This software as well as the software described in it is furnished under
**  license and may only be used or copied in accordance with the terms of the
**  license. The information in this file is furnished for informational use
**  only, is subject to change without notice, and should not be construed as
**  a commitment by Intel Corporation. Intel Corporation assumes no
**  responsibility or liability for any errors or inaccuracies that may appear
**  in this document or any software that may be provided in association with
**  this document.
**  Except as permitted by such license, no part of this document may be
**  reproduced, stored in a retrieval system, or transmitted in any form or by
**  any means without the express written consent of Intel Corporation.
**
**  FILENAME:       i2c.c
**
**
**  LAST MODIFIED:  $Modtime: 9/17/03 9:50a $
******************************************************************************/

#include <stdio.h>
#include  "DRV_i2c.h"
#include "i2c.h"
#include "xllp_intc.h"



/* 
 * Initialization to use I2C bus
 *
 * PARAMETERS:
 *          unsigned int - Default slave device id for Cotulla
 *
 * RETURNS: 
 */
XLLP_UINT32_T i2c_write(P_POST_I2C_T I2C_regs, P_XLLP_INTC_T int_regs, pI2C_TX seq)
{
    XLLP_INT32_T errorLog=0, i=0;
    XLLP_UINT32_T time_out;

   	if((errorLog = PostI2cSetupWrite(I2C_regs, int_regs, seq)) != XLLP_FALSE)
   	  	return(XLLP_TRUE);
     /* Load the I2C Data Buffer Register with device id */

//  this is simulating a interrupt routine
    for(time_out=I2C_TIMEOUT;time_out!=0;time_out--)
    {   
        if( ((int_regs->icpr & XLLP_BIT_6 ) == XLLP_BIT_6)||((int_regs->icpr & XLLP_BIT_18 ) == XLLP_BIT_18))
        {
            errorLog=PostI2cTxEmpty(I2C_regs);
			break;
        }
         if (time_out == 0)   return(XLLP_TRUE);
	}
// this is the end of the simulated interrupt routine
  /* Clear ICR START and TRANSFER bit. The TRANSFER bit should be self 
   * clearing but I'll make sure it is cleared anyway 
   */
   I2C_regs->ICR &= (~(POST_ICR_START | POST_ICR_STOP | POST_ICR_TB));
  

   for(i=0;i<seq->data_len;i++)
   {
   	  if((errorLog = PostI2cWrite(I2C_regs, seq, i, POST_I2C_STOP)) != XLLP_FALSE)
   	       return(XLLP_TRUE);
	
       for(time_out=I2C_TIMEOUT;time_out!=0;time_out--)
       {   
       	   if( ((int_regs->icpr & XLLP_BIT_6 ) == XLLP_BIT_6)||((int_regs->icpr & XLLP_BIT_18 ) == XLLP_BIT_18))
           {
               errorLog=PostI2cTxEmpty(I2C_regs);
			   break;
           }
           if (time_out == 0)   return(XLLP_TRUE);
	    }
	}
    return(errorLog);
}


XLLP_UINT32_T i2c_read(P_POST_I2C_T i2c_regs, P_XLLP_INTC_T int_regs, pI2C_TX seq, P_XLLP_UINT8_T rx_data, XLLP_UINT32_T rx_data_len)
{

  XLLP_UINT32_T time_out;
  XLLP_INT32_T ret = 0; /* success */
  XLLP_INT32_T errorLog=0, i=0;

  /* Write command */
  if((ret = i2c_write(i2c_regs, 
  						int_regs, 
  						seq)) != XLLP_FALSE)
  {
   	return(XLLP_TRUE);
  }

  if((ret = PostI2cSetupRead(i2c_regs, 
  								int_regs, 
  								seq)) != XLLP_FALSE)
  {
   	return(XLLP_TRUE);
  }


    for(time_out=I2C_TIMEOUT;time_out!=0;time_out--)
    {    
       if( ((int_regs->icpr & XLLP_BIT_6 ) == XLLP_BIT_6)||((int_regs->icpr & XLLP_BIT_18 ) == XLLP_BIT_18))
       {
           errorLog=PostI2cTxEmpty(i2c_regs);
	       break;
       }
       if (time_out == 0)   return(XLLP_TRUE);
	}

  /* Clear ICR START and TRANSFER bit. The TRANSFER bit should be self 
   * clearing but I'll make sure it is cleared anyway 
   */

  i2c_regs->ICR &= (~(POST_ICR_START| POST_ICR_TB| POST_ICR_STOP|POST_ICR_ACKNACK));

  for(i=0;i<rx_data_len;i++)
  {
    if(PostI2cRead(i2c_regs, seq, i, rx_data, rx_data_len) != XLLP_FALSE)
   	return(XLLP_TRUE);
 
    for(time_out=I2C_TIMEOUT;time_out!=0;time_out--)
    {    
   	   if( ((int_regs->icpr & XLLP_BIT_6 ) == XLLP_BIT_6)||((int_regs->icpr & XLLP_BIT_18 ) == XLLP_BIT_18))
       {
           errorLog=PostI2cRxFull(i2c_regs);
	       break;
       }
       if (time_out == 0)   return(XLLP_TRUE);
	}
  }
return XLLP_FALSE;
}