can.c

意法半导体STR710的驱动程序

  	CAN->sMsgObj[msg_if].DB2R = 0;

  	CAN->sMsgObj[msg_if].CRR = 1 + msgobj;
}

/*******************************************************************************
* Function Name  : CAN_InvalidateAllMsgObj
* Description    : Configure all the message objects as unused
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
void CAN_InvalidateAllMsgObj(void)
{
	u32 i;
	for (i = 0; i < 32; i++)
		CAN_SetUnusedMsgObj(i);
}

/*******************************************************************************
* Function Name  : CAN_Init
* Description    : Initialize the CAN cell and set the bitrate
* Input 1        : any binary value formed from the CAN_CTL_xxx defines
* Input 2        : one of the CAN_BITRATE_xxx defines
* Output         : None
* Return         : None
*******************************************************************************/
void CAN_Init(u8 mask, u32 bitrate)
{
  CAN_EnterInitMode(CAN_CR_CCE | mask);
  CAN_SetBitrate(bitrate);
  CAN_LeaveInitMode();
  CAN_LeaveTestMode();
}

/*******************************************************************************
* Function Name  : CAN_ReleaseMessage
* Description    : Release the message object
* Input 1        : message object number, from 0 to 31
* Output         : None
* Return         : None
*******************************************************************************/
void CAN_ReleaseMessage(u32 msgobj)
{
	u32 i;
    while ((i = CAN_GetFreeIF()) == 2);

	CAN->sMsgObj[i].CMR = CAN_CMR_CLRINTPND | CAN_CMR_TXRQST;
	CAN->sMsgObj[i].CRR = 1 + msgobj;
}

/*******************************************************************************
* Function Name  : CAN_SendMessage
* Description    : Start transmission of a message
* Input 1        : message object number, from 0 to 31
* Input 2        : pointer to the message structure containing data to transmit
* Output         : None
* Return         : 1 if transmission was OK, else 0
*******************************************************************************/
u32 CAN_SendMessage(u32 msgobj, canmsg* pCanMsg)
{
  while (CAN->sMsgObj[0].CRR & CAN_CRR_BUSY);

/*  if (CAN->sMsgObj[0].COMR & CAN_CRQ_BUSY) */
/*	return 0;	// message interface 0 not free */

  CAN->SR &= ~CAN_SR_TXOK;

  /* read the Arbitration and Message Control */
  CAN->sMsgObj[0].CMR = CAN_CMR_ARB | CAN_CMR_CONTROL;

  CAN->sMsgObj[0].CRR = 1 + msgobj;

  while (CAN->sMsgObj[0].CRR & CAN_CRR_BUSY);

  /* update the contents needed for transmission */
  CAN->sMsgObj[0].CMR =   CAN_CMR_WRRD
  	                | CAN_CMR_ARB
  	                | CAN_CMR_CONTROL
  	                | CAN_CMR_DATAA
  	                | CAN_CMR_DATAB;

  if ((CAN->sMsgObj[0].A2R & CAN_A2R_XTD) == 0)
  {
  	/* standard ID */
	CAN->sMsgObj[0].A1R = 0;
	CAN->sMsgObj[0].A2R = (CAN->sMsgObj[0].A2R & 0xE000) | STD_FIXED_ID_ARB(pCanMsg->Id);
  }
  else
  {
  	// extended ID
	CAN->sMsgObj[0].A1R = EXT_FIXED_ID_ARB_L(pCanMsg->Id);
	CAN->sMsgObj[0].A2R = (CAN->sMsgObj[0].A2R & 0xE000) | EXT_FIXED_ID_ARB_H(pCanMsg->Id);
  }

  CAN->sMsgObj[0].MCR = (CAN->sMsgObj[0].MCR & 0xFEF0) | CAN_MCR_NEWDAT | CAN_MCR_TXRQST | pCanMsg->Dlc;

  CAN->sMsgObj[0].DA1R = ((u16)pCanMsg->Data[1]<<8) | pCanMsg->Data[0];
  CAN->sMsgObj[0].DA2R = ((u16)pCanMsg->Data[3]<<8) | pCanMsg->Data[2];
  CAN->sMsgObj[0].DB1R = ((u16)pCanMsg->Data[5]<<8) | pCanMsg->Data[4];
  CAN->sMsgObj[0].DB2R = ((u16)pCanMsg->Data[7]<<8) | pCanMsg->Data[6];

  CAN->sMsgObj[0].CRR = 1 + msgobj;

  return 1;
}

/*******************************************************************************
* Function Name  : CAN_ReceiveMessage
* Description    : Get the message, if received
* Input 1        : message object number, from 0 to 31
* Input 2        : if TRUE, the message object is released when getting the data
*                  if FALSE, the message object is not released
* Input 3        : pointer to the message structure where received data is stored
* Output         : None
* Return         : 1 if reception was OK, else 0 (no message pending)
*******************************************************************************/
u32 CAN_ReceiveMessage(u32 msgobj, bool release, canmsg* pCanMsg)
{
    if (!CAN_IsMessageWaiting(msgobj))
    	return 0;

	CAN->SR &= ~CAN_SR_RXOK;

    /* read the message contents */
    CAN->sMsgObj[1].CMR =   CAN_CMR_MASK
	                  | CAN_CMR_ARB
	                  | CAN_CMR_CONTROL
	                  | CAN_CMR_CLRINTPND
	                  | (release ? CAN_CMR_TXRQST : 0)
	                  | CAN_CMR_DATAA
	                  | CAN_CMR_DATAB;

	CAN->sMsgObj[1].CRR = 1 + msgobj;

	while (CAN->sMsgObj[1].CRR & CAN_CRR_BUSY);

    if ((CAN->sMsgObj[1].A2R & CAN_A2R_XTD) == 0)
    {
  	  /* standard ID */
  	  pCanMsg->IdType = CAN_STD_ID;
      pCanMsg->Id = (CAN->sMsgObj[1].A2R >> 2) & 0x07FF;
    }
    else
    {
      /* extended ID */
  	  pCanMsg->IdType = CAN_EXT_ID;
      pCanMsg->Id = ((CAN->sMsgObj[1].A2R >> 2) & 0x07FF) | ((u32)CAN->sMsgObj[1].A1R << 11) | (((u32)CAN->sMsgObj[1].A2R & 0x0003) << 27);
    }

    pCanMsg->Dlc = CAN->sMsgObj[1].MCR & 0x0F;

    pCanMsg->Data[0] = (u8) CAN->sMsgObj[1].DA1R;
    pCanMsg->Data[1] = (u8)(CAN->sMsgObj[1].DA1R >> 8);
    pCanMsg->Data[2] = (u8) CAN->sMsgObj[1].DA2R;
    pCanMsg->Data[3] = (u8)(CAN->sMsgObj[1].DA2R >> 8);
    pCanMsg->Data[4] = (u8) CAN->sMsgObj[1].DB1R;
    pCanMsg->Data[5] = (u8)(CAN->sMsgObj[1].DB1R >> 8);
    pCanMsg->Data[6] = (u8) CAN->sMsgObj[1].DB2R;
    pCanMsg->Data[7] = (u8)(CAN->sMsgObj[1].DB2R >> 8);

    return 1;
}

/*******************************************************************************
* Function Name  : CAN_WaitEndOfTx
* Description    : Wait until current transmission is finished
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
void CAN_WaitEndOfTx(void)
{
	while ((CAN->SR & CAN_SR_TXOK) == 0);
	CAN->SR &= ~CAN_SR_TXOK;
}

/*******************************************************************************
* Function Name  : CAN_BasicSendMessage
* Description    : Start transmission of a message in BASIC mode
* Input 1        : pointer to the message structure containing data to transmit
* Output         : None
* Return         : 1 if transmission was OK, else 0
* Note           : CAN must be in BASIC mode
*******************************************************************************/
u32 CAN_BasicSendMessage(canmsg* pCanMsg)
{
	/* clear NewDat bit in IF2 to detect next reception */
	CAN->sMsgObj[1].MCR &= ~CAN_MCR_NEWDAT;

	CAN->SR &= ~CAN_SR_TXOK;

	CAN->sMsgObj[0].CMR = CAN_CMR_WRRD
  	                    | CAN_CMR_ARB
  	                    | CAN_CMR_CONTROL
  	                    | CAN_CMR_DATAA
  	                    | CAN_CMR_DATAB;

	if (pCanMsg->IdType == CAN_STD_ID)
	{
	  	/* standard ID */
		CAN->sMsgObj[0].A1R = 0;
		CAN->sMsgObj[0].A2R = (CAN->sMsgObj[0].A2R & 0xE000) | STD_FIXED_ID_ARB(pCanMsg->Id);
	}
	else
	{
  		/* extended ID */
		CAN->sMsgObj[0].A1R = EXT_FIXED_ID_ARB_L(pCanMsg->Id);
		CAN->sMsgObj[0].A2R = (CAN->sMsgObj[0].A2R & 0xE000) | EXT_FIXED_ID_ARB_H(pCanMsg->Id);
	}

	CAN->sMsgObj[0].MCR = (CAN->sMsgObj[0].MCR & 0xFCF0) | pCanMsg->Dlc;

	CAN->sMsgObj[0].DA1R = ((u16)pCanMsg->Data[1]<<8) | pCanMsg->Data[0];
	CAN->sMsgObj[0].DA2R = ((u16)pCanMsg->Data[3]<<8) | pCanMsg->Data[2];
	CAN->sMsgObj[0].DB1R = ((u16)pCanMsg->Data[5]<<8) | pCanMsg->Data[4];
	CAN->sMsgObj[0].DB2R = ((u16)pCanMsg->Data[7]<<8) | pCanMsg->Data[6];

	/* request transmission */
	CAN->sMsgObj[0].CRR = CAN_CRR_BUSY | (1 + 0);

	return 1;
}

/*******************************************************************************
* Function Name  : CAN_BasicReceiveMessage
* Description    : Get the message in BASIC mode, if received
* Input 1        : pointer to the message structure where received data is stored
* Output         : None
* Return         : 1 if reception was OK, else 0 (no message pending)
* Note           : CAN must be in BASIC mode
*******************************************************************************/
u32 CAN_BasicReceiveMessage(canmsg* pCanMsg)
{
	if ((CAN->sMsgObj[1].MCR & CAN_MCR_NEWDAT) == 0)
		return 0;

	CAN->SR &= ~CAN_SR_RXOK;

	CAN->sMsgObj[1].CMR =  CAN_CMR_ARB
  	                     | CAN_CMR_CONTROL
  	                     | CAN_CMR_DATAA
  	                     | CAN_CMR_DATAB;

    if ((CAN->sMsgObj[1].A2R & CAN_A2R_XTD) == 0)
    {
  	  /* standard ID */
  	  pCanMsg->IdType = CAN_STD_ID;
      pCanMsg->Id = (CAN->sMsgObj[1].A2R >> 2) & 0x07FF;
    }
    else
    {
      /* extended ID */
  	  pCanMsg->IdType = CAN_EXT_ID;
      pCanMsg->Id = ((CAN->sMsgObj[1].A2R >> 2) & 0x07FF) | ((u32)CAN->sMsgObj[1].A1R << 11) | (((u32)CAN->sMsgObj[1].A2R & 0x0003) << 27);
    }

    pCanMsg->Dlc = CAN->sMsgObj[1].MCR & 0x0F;

    pCanMsg->Data[0] = (u8) CAN->sMsgObj[1].DA1R;
    pCanMsg->Data[1] = (u8)(CAN->sMsgObj[1].DA1R >> 8);
    pCanMsg->Data[2] = (u8) CAN->sMsgObj[1].DA2R;
    pCanMsg->Data[3] = (u8)(CAN->sMsgObj[1].DA2R >> 8);
    pCanMsg->Data[4] = (u8) CAN->sMsgObj[1].DB1R;
    pCanMsg->Data[5] = (u8)(CAN->sMsgObj[1].DB1R >> 8);
    pCanMsg->Data[6] = (u8) CAN->sMsgObj[1].DB2R;
    pCanMsg->Data[7] = (u8)(CAN->sMsgObj[1].DB2R >> 8);

    return 1;
}

/******************* (C) COPYRIGHT 2003 STMicroelectronics *****END OF FILE****/