can.c

LPCXpresso1768

/*****************************************************************************
 *  can.c:  CAN module API file for NXP LPC17xx Family Microprocessors
 *
 *   Copyright(C) 2009, NXP Semiconductor
 *   All rights reserved.
 *
 *   History
 *   2009.05.27  ver 1.00    Prelimnary version, first Release
 *
*****************************************************************************/
#include "lpc17xx.h"
#include "type.h"
#include "can.h"

/* Receive Queue: one queue for each CAN port */
extern CAN_MSG MsgBuf_RX1, MsgBuf_RX2;
extern volatile uint32_t CAN1RxDone, CAN2RxDone;

volatile uint32_t CANStatus;
uint32_t CAN1RxCount = 0, CAN2RxCount = 0;
uint32_t CAN1ErrCount = 0, CAN2ErrCount = 0;

/******************************************************************************
** Function name:		CAN_ISR_Rx1
**
** Descriptions:		CAN Rx1 interrupt handler
**
** parameters:			None
** Returned value:		None
** 
******************************************************************************/
void CAN_ISR_Rx1( void )
{
  uint32_t * pDest;

  /* initialize destination pointer	*/
  pDest = (uint32_t *)&MsgBuf_RX1;
  *pDest = LPC_CAN1->RFS;  /* Frame	*/

  pDest++;
  *pDest = LPC_CAN1->RID; /* ID	*/

  pDest++;
  *pDest = LPC_CAN1->RDA; /* Data A */

  pDest++;
  *pDest = LPC_CAN1->RDB; /* Data B	*/
	
  CAN1RxDone = TRUE;
  LPC_CAN1->CMR = 0x01 << 2; /* release receive buffer */
  return;
}

/******************************************************************************
** Function name:		CAN_ISR_Rx2
**
** Descriptions:		CAN Rx2 interrupt handler
**
** parameters:			None
** Returned value:		None
** 
******************************************************************************/
void CAN_ISR_Rx2( void )
{
  uint32_t *pDest;

  /* initialize destination pointer	*/
  pDest = (uint32_t *)&MsgBuf_RX2;
  *pDest = LPC_CAN2->RFS;  /* Frame	*/

  pDest++;
  *pDest = LPC_CAN2->RID; /* ID	*/

  pDest++;
  *pDest = LPC_CAN2->RDA; /* Data A	*/

  pDest++;
  *pDest = LPC_CAN2->RDB; /* Data B	*/

  CAN2RxDone = TRUE;
  LPC_CAN2->CMR = 0x01 << 2; /* release receive buffer */
  return;
}

/*****************************************************************************
** Function name:		CAN_Handler
**
** Descriptions:		CAN interrupt handler
**
** parameters:			None
** Returned value:		None
** 
*****************************************************************************/
void CAN_IRQHandler(void)  
{		

  CANStatus = LPC_CANCR->RxSR;
  if ( CANStatus & (1 << 8) )
  {
	CAN1RxCount++;
	CAN_ISR_Rx1();
  }
  if ( CANStatus & (1 << 9) )
  {
	CAN2RxCount++;
	CAN_ISR_Rx2();
  }
  if ( LPC_CAN1->GSR & (1 << 6 ) )
  {
	/* The error count includes both TX and RX */
	CAN1ErrCount = LPC_CAN1->GSR >> 16;
  }
  if ( LPC_CAN2->GSR & (1 << 6 ) )
  {
	/* The error count includes both TX and RX */
	CAN2ErrCount = LPC_CAN2->GSR >> 16;
  }

  return;
}

/******************************************************************************
** Function name:		CAN_Init
**
** Descriptions:		Initialize CAN, install CAN interrupt handler
**
** parameters:			bitrate
** Returned value:		true or false, false if initialization failed.
** 
******************************************************************************/
uint32_t CAN_Init( uint32_t can_btr )
{
  CAN1RxDone = CAN2RxDone = FALSE;

  LPC_SC->PCONP |= ((1<<13)|(1<<14));  /* Enable CAN1 and CAN2 clock */

  LPC_PINCON->PINSEL0 &= ~0x0000000F;  /* CAN1 is p0.0 and p0.1	*/
  LPC_PINCON->PINSEL0 |= 0x00000005;	
  LPC_PINCON->PINSEL4 &= ~0x0003C000;  /* CAN2 is p2.7 and p2.8 */
  LPC_PINCON->PINSEL4 |= 0x00014000;

  LPC_CAN1->MOD = LPC_CAN2->MOD = 1;    /* Reset CAN */
  LPC_CAN1->IER = LPC_CAN2->IER = 0;    /* Disable Receive Interrupt */
  LPC_CAN1->GSR = LPC_CAN2->GSR = 0;    /* Reset error counter when CANxMOD is in reset	*/

  LPC_CAN1->BTR = LPC_CAN2->BTR = can_btr;
  LPC_CAN1->MOD = LPC_CAN2->MOD = 0x0;  /* CAN in normal operation mode */

  NVIC_EnableIRQ(CAN_IRQn);

  LPC_CAN1->IER = LPC_CAN2->IER = 0x01; /* Enable receive interrupts */
  return( TRUE );
}

/******************************************************************************
** Function name:		CAN_SetACCF_Lookup
**
** Descriptions:		Initialize CAN, install CAN interrupt handler
**
** parameters:			bitrate
** Returned value:		true or false, false if initialization failed.
** 
******************************************************************************/
void CAN_SetACCF_Lookup( void )
{
  uint32_t address = 0;
  uint32_t i;
  uint32_t ID_high, ID_low;

  /* Set explicit standard Frame */ 
  LPC_CANAF->SFF_sa = address;
  for ( i = 0; i < ACCF_IDEN_NUM; i += 2 )
  {
	ID_low = (i << 29) | (EXP_STD_ID << 16);
	ID_high = ((i+1) << 13) | (EXP_STD_ID << 0);
	*((volatile uint32_t *)(LPC_CANAF_RAM_BASE + address)) = ID_low | ID_high;
	address += 4; 
  }
		
  /* Set group standard Frame */
  LPC_CANAF->SFF_GRP_sa = address;
  for ( i = 0; i < ACCF_IDEN_NUM; i += 2 )
  {
	ID_low = (i << 29) | (GRP_STD_ID << 16);
	ID_high = ((i+1) << 13) | (GRP_STD_ID << 0);
	*((volatile uint32_t *)(LPC_CANAF_RAM_BASE + address)) = ID_low | ID_high;
	address += 4; 
  }
 
  /* Set explicit extended Frame */ 
  LPC_CANAF->EFF_sa = address;
  for ( i = 0; i < ACCF_IDEN_NUM; i++  )
  {
	ID_low = (i << 29) | (EXP_EXT_ID << 0);
	*((volatile uint32_t *)(LPC_CANAF_RAM_BASE + address)) = ID_low;
	address += 4; 
  }

  /* Set group extended Frame */
  LPC_CANAF->EFF_GRP_sa = address;
  for ( i = 0; i < ACCF_IDEN_NUM; i++  )
  {
	ID_low = (i << 29) | (GRP_EXT_ID << 0);
	*((volatile uint32_t *)(LPC_CANAF_RAM_BASE + address)) = ID_low;
	address += 4; 
  }
   
  /* Set End of Table */
  LPC_CANAF->ENDofTable = address;
  return;
}

/******************************************************************************
** Function name:		CAN_SetACCF
**
** Descriptions:		Set acceptance filter and SRAM associated with	
**
** parameters:			ACMF mode
** Returned value:		None
**
** 
******************************************************************************/
void CAN_SetACCF( uint32_t ACCFMode )
{
  switch ( ACCFMode )
  {
	case ACCF_OFF:
	  LPC_CANAF->AFMR = ACCFMode;
	  LPC_CAN1->MOD = LPC_CAN2->MOD = 1;	// Reset CAN
	  LPC_CAN1->IER = LPC_CAN2->IER = 0;	// Disable Receive Interrupt
	  LPC_CAN1->GSR = LPC_CAN2->GSR = 0;	// Reset error counter when CANxMOD is in reset
	break;

	case ACCF_BYPASS:
	  LPC_CANAF->AFMR = ACCFMode;
	break;

	case ACCF_ON:
	case ACCF_FULLCAN:
	  LPC_CANAF->AFMR = ACCF_OFF;
	  CAN_SetACCF_Lookup();
	  LPC_CANAF->AFMR = ACCFMode;
	break;

	default:
	break;
  }
  return;
}

/******************************************************************************
** Function name:		CAN1_SendMessage
**
** Descriptions:		Send message block to CAN1	
**
** parameters:			pointer to the CAN message
** Returned value:		true or false, if message buffer is available,
**						message can be sent successfully, return TRUE,
**						otherwise, return FALSE.
** 
******************************************************************************/
uint32_t CAN1_SendMessage( CAN_MSG *pTxBuf )
{
  uint32_t CANStatus;

  CANStatus = LPC_CAN1->SR;
  if ( CANStatus & 0x00000004 )
  {
	LPC_CAN1->TFI1 = pTxBuf->Frame & 0xC00F0000;
	LPC_CAN1->TID1 = pTxBuf->MsgID;
	LPC_CAN1->TDA1 = pTxBuf->DataA;
	LPC_CAN1->TDB1 = pTxBuf->DataB;
	LPC_CAN1->CMR = 0x21;
	return ( TRUE );
  }
  else if ( CANStatus & 0x00000400 )
  {
	LPC_CAN1->TFI2 = pTxBuf->Frame & 0xC00F0000;
	LPC_CAN1->TID2 = pTxBuf->MsgID;
	LPC_CAN1->TDA2 = pTxBuf->DataA;
	LPC_CAN1->TDB2 = pTxBuf->DataB;
	LPC_CAN1->CMR = 0x41;
	return ( TRUE );
  }
  else if ( CANStatus & 0x00040000 )
  {	
	LPC_CAN1->TFI3 = pTxBuf->Frame & 0xC00F0000;
	LPC_CAN1->TID3 = pTxBuf->MsgID;
	LPC_CAN1->TDA3 = pTxBuf->DataA;
	LPC_CAN1->TDB3 = pTxBuf->DataB;
	LPC_CAN1->CMR = 0x81;
	return ( TRUE );
  }
  return ( FALSE );
}

/******************************************************************************
**                            End Of File
******************************************************************************/