#include    "Includes.h"


 typedef struct{
	uint32_t id28_18:11;
	uint32_t id17_00:18;
	uint32_t ide:1;
	uint32_t rtr:1;
	uint32_t NA0:1;
	uint32_t len;
	uint8_t dat[8];
}CAN_INFO;
 
void can_pin_init(void)
{
	gpio_mux_ctl(8,2);//tx
	gpio_mux_ctl(9,2);//rx
}
/*
FPGA OSC_12M
tq=2*tclk(BRP+1)     //CAN_BTR0->BRP

Tsyncseg=1*tq
Ttseg1=tq*(TSEG1+1)  //CAN_BTR1->TSEG1
Ttseg2=tq*(TSEG2+1)  //CAN_BTR1->TSEG2

can_baud=1/(Tsyncseg+Ttseg1+Ttseg2)
        =1/(tq*(1+6+1+7+1))
        =1/(tq*16)
        =1/(16*2*tclk*(2+1))
        =1/(16*6*tclk) 
        =1/(96*tclk) 
        =1/(96*(1/12M))=12M/96=12000000/96=125000bps 
*/

void can_init(void)
{
  

	__write_hw_reg32(((volatile unsigned *)(CPR_BASE+0x24)),0x00110014);//CPR_CTL_PCLK_GRCTL(pclk=mclk/2)
    CPR_CAN_CLK_CTL->CAN_PCLK_EN=1;
	CPR_CAN_CLK_CTL->CAN_MCLK_EN=1;
	CPR_CAN_CLK_CTL->CAN_MCLK_DIV=0;
 
	CAN_CDR->CDR3=0x07;
	CAN_CDR->CDR4=0x0C;
//	CAN_IER->TIE=1;
	CAN_IER->RIE=1;
	
	CAN_MOD->RM=1;
	//config can baud
    CAN_OCR->OCMODE=2;
	CAN_BTR0->BRP=2;
	CAN_BTR0->SJW=2;
	CAN_BTR1->TSEG2=7;
	CAN_BTR1->TSEG1=6;
	//config can filter
    CAN_MOD->AFM=1;//single filter
	*CAN_ACR0=0x00;//id28-21
	*CAN_ACR1=0x00;//id20-13
	*CAN_ACR2=0x00;//id12-05
	*CAN_ACR3=0x00;//id04-00 +rtr
	*CAN_AMR0=0x00;//1 identify the corresponding bits as do not care
	*CAN_AMR1=0x10;
	*CAN_AMR2=0x00;
	*CAN_AMR3=0x04;//*CAN_AMR3=0x04;

	CAN_MOD->RM=0;
	 	//config rev filter
	
	
}
uint8_t Buffer_Released,Transmission_Complete;
uint8_t  can_send_mes(CAN_INFO *can_information)
{
	uint8_t fifo_index;
  //if(CAN_SR->TBS == 0) return 1;// CAN_SR->TBS ----volatile
	while(CAN_SR->TBS == 0); //wait transmit buffer released.  CAN_SR->TBS ----volatile
	*CAN_FI = (can_information->len&(0xF))|((can_information->rtr)<<6)|((can_information->ide)<<7);//1:remote frame  ,  0:data frame  
	if(can_information->ide){//extended frame format
        *CAN_ID1=(can_information->id28_18)>>3;
	    *CAN_ID2=(((can_information->id28_18)&0x07)<<5)|((can_information->id17_00)>>13);
		*CAN_ID3=((can_information->id17_00)>>5)&0xFF;
		*CAN_ID4=((can_information->id17_00)&0x1F)<<3;
		fifo_index=2;
	}else{ //standard frame format 
		*CAN_ID1=(can_information->id28_18)>>3;
	    *CAN_ID2=((can_information->id28_18)&0x07)<<5;
		fifo_index=0;
	}
    if(can_information->rtr == 0)
	{
		for(uint8_t i=0;i<8;i++)
		{
		   __write_hw_reg32(CAN_TX_BUFF(fifo_index++), can_information->dat[i]); //set transmission data
		}
    }
	CAN_CMR->TR=0x01;	
	return 0;
}

uint8_t can_receive_msg(CAN_INFO *can_information)
{
	uint8_t fifo_index;
 	if(CAN_SR->RBS==0) return 0;
	can_information->ide = *CAN_FI&0x80 ? 1:0; /*0:standard_frame , 1:extended_frame*/
	can_information->rtr = *CAN_FI&0x40 ? 1:0; /*0:data frame     , 1:remote frame  */
	can_information->len = *CAN_FI&0xF;	
	if(can_information->len>8) 
	{
		can_information->len=8;
	}
	can_information->id28_18=(*CAN_ID1<<3)|(*CAN_ID2>>5);
	if(can_information->ide){//1:extended 
	    can_information->id17_00=((*CAN_ID2&0x1F)<<13)|(*CAN_ID3<<5)|(*CAN_ID4>>3);
		fifo_index=2;
	}else{//1:standard 
	    fifo_index=0;
	} 
	if(can_information->rtr==0) 
	{
		for(int i=0;i<can_information->len;i++)
		{
		   __read_hw_reg32(CAN_RX_BUFF(fifo_index++), can_information->dat[i]);
		}
	}
	CAN_CMR->RRB=1;	/* Release the FIFO */
	return can_information->len;
	
	
}
void tx_msg(void)
{
	    static CAN_INFO can_tmsg={
		.rtr=0,//1:remote frame  ,  0:data frame  
		.ide=1,//1:extended frame format , 0:standard frame format 
		.len=8,
		.id28_18=0x12,
		.id17_00=0x73,
		.dat[0]=0x01,
		.dat[1]=0x02,
		.dat[2]=0x03,
		.dat[3]=0x04,
		.dat[4]=0x05,
		.dat[5]=0x06,
		.dat[6]=0x07,
		.dat[7]=0x08,
	}; 
#if 1	//tx
		 can_tmsg.dat[0]++;
		 if(can_tmsg.rtr)//1: remote frame(remote frame has no data part)
		 {
		   if(can_tmsg.len>=8)
		   {
		      can_tmsg.len=1;//request length
		   }else
		   {
		      can_tmsg.len++;//request length
		   }
	     }
 		 can_send_mes(&can_tmsg);
#endif
	
	


}
void rx_msg(void)
{
	 CAN_INFO can_rmsg;
	 if(can_receive_msg(&can_rmsg))
	 {
		 printf("id28_18=%#x ,id17_00=%#x ,rtr=%#x ,ide=%#x ,len=%#x \n",can_rmsg.id28_18,can_rmsg.id17_00,can_rmsg.rtr,can_rmsg.ide,can_rmsg.len);
		 if(can_rmsg.rtr==0)
		 {
			printf("dat:");
			for(int i=0;i<can_rmsg.len;i++)  printf("%#x ",can_rmsg.dat[i]);
			printf("\n");
		 }
	 }


}
void CAN_Handler(void)
{
   rx_msg();
}	
void test_can(void)
{
	can_pin_init();
	can_init();
    NVIC_EnableIRQ(CAN_IRQn);
	while(1)
	{
      tx_msg();	
      	
   	}
	
	
}