i2c1_drv.c

nxp lpc177x/8x lcd keil&iar 例程

/*************************************************************************
 *
*    Used with ICCARM and AARM.
 *
 *    (c) Copyright IAR Systems 2007
 *
 *    File name   : i2c1_drv.c
 *    Description : I2C1 driver
 *
 *    History :
 *    1. Date        : 13, February 2008
 *       Author      : Stanimir Bonev
 *       Description : Create
 *
 *
 *    $Revision: 22899 $
 *
 *    @Modify: NXP MCU Application Team - NguyenCao
 *    @Date: 04. March. 2011
 **************************************************************************/
#include "i2c1_drv.h"
#include "board.h"
#include "lpc177x_8x_clkpwr.h"
#include "lpc177x_8x_pinsel.h"

volatile int	  I2CState;
LPC_I2C_Msg_t	  I2CMsg;

/*************************************************************************
 * Function Name: I2C_EnableI2C
 * Parameters: void
 * Return: void
 * Description: Enable I2C device.
 *************************************************************************/
#pragma inline
void I2C_EnableI2C(void)
{
  LPC_I2C1->CONSET |= I2CON_I2EN;
}

/*************************************************************************
 * Function Name: I2C_DisableI2C
 * Parameters: void
 * Return: void
 * Description: Disable I2C device.
 *************************************************************************/
#pragma inline
void I2C_DisableI2C(void)
{
  LPC_I2C1->CONCLR = I2CON_I2ENC;
}

/*************************************************************************
 * Function Name: __I2C_SetFlag
 * Parameters: int FlagType -- AA, INT and START and STOP
 *
 * Return: void
 * Description: Set the flag.
 *
 *************************************************************************/
#pragma inline
void __I2C_SetFlag (int FlagType)
{
  LPC_I2C1->CONSET |= FlagType;
}

/*************************************************************************
 * Function Name: __I2C_ClearFlag
 * Parameters: int FlagType -- AA, INT and START (Excl. STOP)
 *
 * Return: void
 * Description: Clear the flag.
 *
 *************************************************************************/
#pragma inline
void __I2C_ClearFlag (int FlagType)
{
  LPC_I2C1->CONCLR = FlagType;
}

/*************************************************************************
 * Function Name: __I2C_SendData
 * Parameters: unsigned char data
 * Return: void
 * Description: Load data to I2CDAT. Just used in I2C module.
 *************************************************************************/
#pragma inline
void __I2C_SendData(unsigned char data)
{
  LPC_I2C1->DAT = data;
}

/*************************************************************************
 * Function Name: __I2C_ReceiveData
 * Parameters: void
 * Return: unsigned char
 * Description: Load data from I2CDAT. Just used in I2C module.
 *************************************************************************/
#pragma inline
unsigned char __I2C_ReceiveData(void)
{
  return LPC_I2C1->DAT;
}

/*************************************************************************
 * Function Name: I2C_InitMaster
 * Parameters: unsigned long BusSpeed
 *
 * Return: int
 *             	0: success
 *	 non-zero: error number
 * Description: Initialize the current device as I2C bus master.
 *
 *************************************************************************/
int I2C_InitMaster (unsigned long BusSpeed)
{
    uint32_t i2cclk;
    //Enable clock for I2C1
    CLKPWR_ConfigPPWR(CLKPWR_PCONP_PCI2C1, ENABLE);
    if (BusSpeed > I2C_MAXSPEED)
      return 1;
    I2C_DisableI2C();

     i2cclk = CLKPWR_GetCLK(CLKPWR_CLKTYPE_PER);
    // value of I2SCLH and I2SCLL must be different
    LPC_I2C1->SCLH = ((i2cclk / BusSpeed) / 2) + 1;
    LPC_I2C1->SCLL = (i2cclk/ BusSpeed) / 2;

    if (LPC_I2C1->SCLH < 4 || LPC_I2C1->SCLL < 4)
      return 1;

    I2CState = I2C_IDLE;

    LPC_IOCON->P2_14 = 0x32;
    LPC_IOCON->P2_15 = 0x32;

    // Enable I2C
    I2C_EnableI2C();
    __I2C_ClearFlag(I2CON_STAC | I2CON_SIC | I2CON_AAC);

    return 0;
}

/*************************************************************************
 * Function Name: I2C_MasterWrite
 * Parameters:  unsigned char addr -- the slave address which you send message to
 *		unsigned char *pMsg -- the point to the message
 *		unsigned long numMsg -- the byte number of the message
 * Return: int
 *             	0: success
 *       non-zero: error number
 *
 * Description: Transmit messages
 *
 *************************************************************************/
int I2C_MasterWrite (unsigned char addr, unsigned char *pMsg , unsigned long numMsg)
{
  return I2C_Transfer (addr, pMsg , numMsg, WRITE, 0);
}


/*************************************************************************
 * Function Name: I2C_MasterRead
 * Parameters:  unsigned char addr -- the slave address which you send message to
 *		unsigned char *pMsg -- the point to the message
 *		unsigned long numMsg -- the byte number of the message
 * Return: int
 *             	0: success
 *	 non-zero: error number
 *
 * Description: Receive messages
 *
 *************************************************************************/
int I2C_MasterRead (unsigned char addr, unsigned char *pMsg , unsigned long numMsg)
{
  return I2C_Transfer (addr, pMsg , numMsg, READ, 0);
}

/*************************************************************************
 * Function Name: I2C_Transfer
 * Parameters:  unsigned char addr -- the slave address which you send message to
 *		unsigned char *pMsg -- the point to the message
 *		unsigned long numMsg -- the byte number of the message
 *		LPC_I2C_TransMode_t transMode -- Read, Write, Write then read
 *		unsigned long numWrite -- this is only for "Write then read" mode
 *
 * Return: int
 *             	0: success
 *       non-zero: error number
 *
 * Description: Transfer messages
 *
 *************************************************************************/
int I2C_Transfer (unsigned char addr, unsigned char *pMsg , unsigned long numMsg,
	          LPC_I2C_TransMode_t transMode, unsigned long numWrite)
{
unsigned int timeout = DLY_I2C_TIME_OUT;
  if (transMode == WRITETHENREAD)
  {
    if (numWrite >= numMsg)
      return 1;
    else
      I2CMsg.nrWriteBytes = numWrite;
  }
  else
    I2CMsg.nrWriteBytes = 0;

	I2CMsg.buf       = pMsg;
  I2CMsg.nrBytes   = numMsg;
  I2CMsg.address   = addr;
  I2CMsg.transMode = transMode;
  I2CMsg.dataCount = 0;

  __I2C_SetFlag(I2CON_STA);

  I2CState = I2C_BUSY;

  while(I2CState == I2C_BUSY)
  {
    // Wait the interrupt
    if (LPC_I2C1->CONSET & 0x08)
    {
      I2C_HandleMasterState();    // Master Mode
      timeout = DLY_I2C_TIME_OUT;
    }
    if (timeout-- == 0)
    {
      I2CState = I2C_TIME_OUT;
    }
  }

#ifdef __DEBUG__
  if (I2C_OK != I2CState) {
    printf("I2C error : %d\n",I2CState);
    I2C_InitMaster(I2C_SPEED);
  }
#endif
  __I2C_ClearFlag(I2CON_STAC | I2CON_AAC);

  return I2CState;
}


/*************************************************************************
 * Function Name: I2C_HandleMasterState
 * Parameters: void
 * Return: void
 * Description: Master mode state handler for I2C bus.
 *
 *************************************************************************/
void I2C_HandleMasterState(void)
{
unsigned long I2Cstatus = LPC_I2C1->STAT & 0xF8;

  switch (I2Cstatus)
  {
/* ------- MASTER TRANSMITTER FUNCTIONS ----------- */
  case 0x08 : // start condition transmitted
  case 0x10 : // restart condition transmitted
    if (I2CMsg.transMode == WRITETHENREAD)
    {
      if (I2CMsg.dataCount < I2CMsg.nrWriteBytes)
        __I2C_SendData((I2CMsg.address<<1) | WRITE);
      else
      {
        __I2C_SendData((I2CMsg.address<<1) | READ );
      }
    }
    else
    {
      __I2C_SendData((I2CMsg.address<<1) | I2CMsg.transMode);
    }
    __I2C_ClearFlag(I2CON_STAC);	// STA bit
    break;
  case 0x18 : // SLA+W transmitted and ACK received
    if ( I2CMsg.nrBytes == 0 )
    {
      __I2C_SetFlag  (I2CON_STO);             // STO bit clear automatically
      I2CState = I2C_NO_DATA;
    }
    else
    {
      // Send next data byte
      __I2C_SendData(I2CMsg.buf[I2CMsg.dataCount++]);
    }
    break;
  case 0x20 : // SLA+W transmitted, but no ACK received
    __I2C_SetFlag  (I2CON_STO);
    I2CState = I2C_NACK_ON_ADDRESS;
    break;
  case 0x28 : //Data byte transmitted and ACK received
    if (I2CMsg.transMode == WRITE)
    {
      if (I2CMsg.dataCount < I2CMsg.nrBytes)
      {
        __I2C_SendData (I2CMsg.buf[I2CMsg.dataCount++]);
      }
      else
      {
        __I2C_SetFlag  (I2CON_STO); // data transmit finished, stop transmit
        I2CState = I2C_OK;
      }
    }
    else if (I2CMsg.transMode == WRITETHENREAD)
    {
      if (I2CMsg.dataCount < I2CMsg.nrWriteBytes)
      {
        __I2C_SendData (I2CMsg.buf[I2CMsg.dataCount++]);
      }
      else		// send start condition
      {
        __I2C_SetFlag  (I2CON_STA);
      }
    }
    break;
  case 0x30 : // no ACK for data byte
    __I2C_SetFlag  (I2CON_STO);
    I2CState = I2C_NACK_ON_DATA;
    break;
  case 0x38 : // arbitration lost in Slave Address or Data bytes
    I2CState = I2C_ARBITRATION_LOST;
    break;

/* ------- MASTER RECEIVER FUNCTIONS ----------- */
  case 0x40 : // ACK for slave address + R
    if (I2CMsg.nrBytes>1)
    {
      __I2C_SetFlag  (I2CON_AA );	// send acknowledge byte
    }
    else
    {
      __I2C_ClearFlag(I2CON_AAC); // return NACK
    }
    break;
  case 0x48 : // no ACK for slave address + R
    __I2C_SetFlag  (I2CON_STO);
    I2CState = I2C_NACK_ON_ADDRESS;
    break;
  case 0x50 : // ACK for data byte
    I2CMsg.buf[I2CMsg.dataCount++] = __I2C_ReceiveData();
    if (I2CMsg.dataCount + 1 < I2CMsg.nrBytes)
    {
      __I2C_SetFlag(I2CON_AA );	  // send acknowledge byte
    }
    else
    {
      __I2C_ClearFlag(I2CON_AAC); // return NACK
    }
    break;
  case 0x58 : // no ACK for data byte
    I2CMsg.buf[I2CMsg.dataCount++] = __I2C_ReceiveData();

    __I2C_SetFlag  (I2CON_STO);
    I2CState = I2C_OK;
    break;
  default : // undefined error
    __I2C_SetFlag  (I2CON_STO);
    __I2C_ClearFlag(I2CON_STAC | I2CON_AAC);
    I2CState = I2C_ERROR;
    break;
  } // switch - I2C_I2STAT & 0xF8
  __I2C_ClearFlag(I2CON_SIC);
}