/*******************************************************************************             Copyright (C) 2002 by Ingenient Technologies, Inc.*                            All Rights Reserved.**             Use of this software is restricted to the terms and*            conditions of Ingenient's software license agreement.**                             www.ingenient.com*********************************************************************************  Filename:**     i2c.c**  File Description:**     This file contains the I2C driver functions*******************************************************************************/#include "i2c.h"/* *************************   Global Variables   ************************* */static UINT16 i2c_scl,i2c_sda;static volatile UINT16 *dir_scl, *bitset_scl, *bitclr_scl;static volatile UINT16 *dir_sda, *bitset_sda, *bitclr_sda;/* ***********************   Function Prototypes   ************************ */static void  makeSclLow(void);static void  makeSclHigh(void);static void  makeSdaLow(void);static void  makeSdaHigh(void);static BOOL  readSda(void);static void  makeSdaInput(void);static void  makeSdaOutput(void);static void  i2cStart(void);static void  i2cStop(void);static BOOL  i2cReadBit(void);static void  i2cWriteBit(BOOL bit);static BOOL  i2cGetAck(void);static void  i2cSendAck(void);static void  i2cSendNack(void);static UINT8 i2cReadByte(void);static void  i2cWriteByte(UINT8 byte);static void  i2cWait(void);/* ****************************   BEGIN CODE   **************************** *//* main initialization function */void I2C_init(INT16 scl_gio, INT16 sda_gio){   /* configure pointers based on GIO usage */   if (scl_gio >= 32)   {      dir_scl = DIR2;      bitset_scl = BITSET2;      bitclr_scl = BITCLR2;      i2c_scl = 1 << (scl_gio-32);   }   else if (scl_gio >= 16)   {      dir_scl = DIR1;      bitset_scl = BITSET1; 	  bitclr_scl = BITCLR1;      i2c_scl = 1 << (scl_gio-16);   }   else  {         dir_scl = DIR0;         bitset_scl = BITSET0;         bitclr_scl = BITCLR0;         i2c_scl = 1 << scl_gio;   }   if (sda_gio >= 32)   {      dir_sda = DIR2;      bitset_sda = BITSET2;      bitclr_sda = BITCLR2;      i2c_sda = 1 << (sda_gio-32);   }   else if (sda_gio >= 16)      {         dir_sda = DIR1;         bitset_sda = BITSET1;         bitclr_sda = BITCLR1;         i2c_sda = 1 << (sda_gio-16);      }      else      {         dir_sda = DIR0;         bitset_sda = BITSET0;         bitclr_sda = BITCLR0;         i2c_sda = 1 << sda_gio;      }   /* configure the 2 GIO lines as outputs */   *dir_scl &= ~i2c_scl;   *dir_sda &= ~i2c_sda;   /* put bus in stop state */   i2cStop();}void I2C_writeReg(UINT8 slaveAddr, UINT8 subAddr, UINT8 val,                 UINT8 *successFlag){   UINT8 flag=1;   i2cStart();   i2cWriteByte(slaveAddr & 0xfe);      /* LSb = 0 for write */   flag &= i2cGetAck();   i2cWriteByte(subAddr);   flag &= i2cGetAck();   i2cWriteByte(val);   flag &= i2cGetAck();   i2cStop();   *successFlag = (flag) ? I2C_SUCCESS : I2C_ERROR;}void I2C_writeRegs(UINT8 slaveAddr, UINT8 subAddr, UINT8 *val,                  UINT32 count, UINT8 *successFlag){   UINT8 i, flag=1;   i2cStart();   i2cWriteByte(slaveAddr & 0xfe);      /* LSb = 0 for write */   flag &= i2cGetAck();   i2cWriteByte(subAddr);   flag &= i2cGetAck();   for (i = 0; i < count; i++)   {      i2cWriteByte(val[i]);      flag &= i2cGetAck();   }   i2cStop();   *successFlag = (flag) ? I2C_SUCCESS : I2C_ERROR;}unsigned char I2C_readReg(UINT8 slaveAddr, UINT8 subAddr,                 UINT8 *successFlag){   UINT8 val, flag=1;   i2cStart();   i2cWriteByte(slaveAddr & 0xfe);      /* LSb = 0 for write */   flag &= i2cGetAck();   i2cWriteByte(subAddr);   flag &= i2cGetAck();   i2cStart();   i2cWriteByte(slaveAddr | 0x01);      /* LSb = 1 for read */   flag &= i2cGetAck();   makeSdaInput();   i2cWait();   val = i2cReadByte();   makeSdaOutput();   i2cWait();   i2cSendNack();   i2cStop();   *successFlag = (flag) ? I2C_SUCCESS : I2C_ERROR;   return val;}void I2C_readRegs(UINT8 slaveAddr, UINT8 subAddr, UINT8 *val,                 UINT32 count, UINT8 *successFlag){   UINT32 i, flag=1;   i2cStart();   i2cWriteByte(0xfe&slaveAddr); // "write" must be even number   flag &= i2cGetAck();   i2cWriteByte(subAddr);   flag &= i2cGetAck();   i2cStart();   i2cWriteByte((0xfe&slaveAddr)+1);   flag &= i2cGetAck();   for(i=0; i<count; i++)   {      val[i] = i2cReadByte();      if (i == count-1)         i2cSendNack();      else         i2cSendAck();   }   i2cStop();}/* **********************   Local Helper Functions   ********************** *//* write a '0' to SCL */static void makeSclLow(void){   *bitclr_scl = i2c_scl;}/* write a '1' to SCL */static void makeSclHigh(void){   *bitset_scl = i2c_scl;}/* write a '0' to SDA */static void makeSdaLow(void){   *bitclr_sda = i2c_sda;}/* write a '1' to SDA */static void makeSdaHigh(void){   *bitset_sda = i2c_sda;}/* read SDA */static BOOL readSda(void){   UINT16 usTemp;   usTemp = *bitset_sda;   if ((usTemp & i2c_sda) != 0)      return (BOOL)1;   else      return (BOOL)0;}/* set SDA as input */static void makeSdaInput(void){   *dir_sda |= i2c_sda;}/* set SDA as output */static void makeSdaOutput(void){   makeSdaHigh();                       /* was pulled up, keep same state */   *dir_sda &= ~i2c_sda;}static void i2cStart(void){   makeSdaHigh();   makeSclHigh();   i2cWait();   makeSdaLow();   i2cWait();   makeSclLow();   i2cWait();}static void i2cStop(void){   makeSdaLow();   makeSclHigh();   i2cWait();   makeSdaHigh();   i2cWait();}static BOOL i2cReadBit(void){   BOOL bit;   makeSclHigh();   i2cWait();//   i2cWait();//   i2cWait();//   i2cWait();//   i2cWait();//   i2cWait();   bit = readSda();   makeSclLow();   i2cWait();   return bit;}static void i2cWriteBit(BOOL bit){   if (bit)      makeSdaHigh();   else      makeSdaLow();   makeSclHigh();   i2cWait();   makeSclLow();}static BOOL i2cGetAck(void){   BOOL ackVal;   makeSdaInput();   i2cWait();   ackVal = (BOOL)(!i2cReadBit());      /* 0 - Ack, 1 - NACK */   makeSdaOutput();   i2cWait();   return ackVal;}static void i2cSendNack(void){   i2cWriteBit((BOOL)1);}static void i2cSendAck(void){   i2cWriteBit((BOOL)0);}static UINT8 i2cReadByte(void){   UINT8 i, mask=0x80, retVal=0;   for (i = 0; i < 8; i++)   {      if (i2cReadBit())         retVal |= mask;      mask >>= 1;   }   return retVal;}static void i2cWriteByte(UINT8 byte){   UINT8 i, mask=0x80;   for (i = 0; i < 8; i++)   {      if (byte & mask)         i2cWriteBit((BOOL)1);      else         i2cWriteBit((BOOL)0);      mask >>= 1;   }}static void i2cWait(void){   volatile int i;   for (i = 0; i < 100; i++)      ;}