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/*********************************************************************

 *

 *                  CAN module

 *

 *********************************************************************

 * FileName:        $HeadURL: https://svn.auml.se/svn/HomeAutomation/trunk/EmbeddedSoftware/PIC/canBase/Source/CAN.c $

 * Last changed:    $LastChangedDate: 2007-02-25 20:51:08 +0100 (Sun, 25 Feb 2007) $

 * By:              $LastChangedBy: johboh $

 * Revision:        $Revision: 339 $

 ********************************************************************/

#include <CANdefs.h>

#include <stackTasks.h>

#include <CAN.h>

#include <EEaccess.h>

#include <funcdefs.h>

#include <Tick.h>

TICK heartbeat;

static int MY_ID = DEFAULT_ID;

static CAN_PACKET outCp;

static void canGetPacket(void);

/*

*   Function: canInit

*

*   Input:  none

*   Output: none

*   Pre-conditions: none

*   Affects: Changes can registers.

*   Depends: none.

*/

void canInit()

{

    CANCON = 0x80; //request config mode

    while ((CANSTAT & 0xE0) != 0x80 ); //wait for config mode request

    // BAUD AND TQS

    // 500Khz@40Mhz (new by the book)

    BRGCON1 = 0x04;

    BRGCON2 = 0xD1;

    BRGCON3 = 0x81;

    //BRGCON1=0;

    // Sync_Seq = 2 x TQ = 1

    //BRGCON1bits.SJW1=0;

    //BRGCON1bits.SJW0=1;

    // Setting BRP.

    //BRGCON1=BRGCON1|CAN_BRP;

    // Maximum PHEG1

    //BRGCON2bits.SEG2PHTS = 1;

    // Phase_Seg1 = 2 x TQ = 1

    //BRGCON2bits.SEG1PH2 = 0;

    //BRGCON2bits.SEG1PH1 = 0;

    //BRGCON2bits.SEG1PH0 = 1;

    // Prop_Seq = 2 x TQ = 1

    //BRGCON2bits.PRSEG2 = 0;

    //BRGCON2bits.PRSEG1 = 0;

    //BRGCON2bits.PRSEG0 = 1;

    //  Enableing bus wake-up

    //BRGCON3bits.WAKDIS = 0;

    // Dont use filter when wakeup

    //BRGCON3bits.WAKFIL = 0;

    // Phase_Seg2 = 2 x TQ = 1

    //BRGCON3bits.SEG2PH2 = 0;

    //BRGCON3bits.SEG2PH1 = 0;

    //BRGCON3bits.SEG2PH0 = 1;

    ECANCON=0;

    ECANCONbits.MDSEL1 = 1; // 0  For mode 1 

    ECANCONbits.MDSEL0 = 0; // 1  For mode 1 

    // FILTERS AND MASKS

    RXB0CONbits.RXM1=1;

    RXB0CONbits.RXM0=0;

    // INTERRUPTS

    // Diable transmit interrupt

    TXBIE = 0;

    //rx any interrupt

    PIR3 = 0;

    PIE3 = 0b00000011;

    // High interrupt

    IPR3 =0b00000011;

    // Programmable buffers interrupt

    BIE0  = 0xFF;  

    //loopback mode or not

    #ifdef CAN_LOOPBACK_MODE

        CANCON = 0x40;//request loopback mode

        while ((CANSTAT & 0xE0) != 0x40 );//wait for loopback mode

    #else

        CANCON = 0x00;//request normal mode

        while ((CANSTAT & 0xE0) != 0x00 );//wait for normal mode

    #endif

    // Init ticker service

    tickInit();

    // Read ID and NID if exist.

    if (EERead(NODE_ID_EE)==NODE_HAS_ID)

    {

        MY_ID=+EERead(NODE_ID_EE + 1);

    }

    // Send user program startup heatbeat

    outCp.type=ptPGM;

    outCp.pgm.class=pcCTRL;

    outCp.pgm.id=pctAPPBOOT;

    outCp.length=0;

    while(!canSendMessage(outCp,PRIO_HIGH));

}

/*

*   Function: canISR

*

*   Input:  none

*   Output: none

*   Pre-conditions: a call to canInit()

*   Affects: interrupt registers and receive data buffers

*   Depends: ..

*/

void canISR()

{

    ClrWdt();

    if (PIR3bits.RXBnIF || PIR3bits.RXB1IF || PIR3bits.RXB0IF)

    {

        ECANCON=(ECANCON&0b00000)|(0b10000|(CANCON&0x0F));

        if (RXB0CONbits.RXFUL) canGetPacket();

        if (PIR3bits.RXBnIF) {PIR3bits.RXBnIF = 0; return;}

        if (PIR3bits.RXB1IF) {PIR3bits.RXB1IF = 0; return;}

        if (PIR3bits.RXB0IF) {PIR3bits.RXB0IF = 0; return;}

    }

    tickUpdate();

    if ((tickGet()-heartbeat)>TICK_SECOND*5)

    {

        // Send alive heartbeat

        outCp.type=ptPGM;

        outCp.pgm.class=pcCTRL;

        outCp.pgm.id=pctHEARTBEAT;

        outCp.length=0;

        canSendMessage(outCp,PRIO_HIGH);

        heartbeat = tickGet();

    }

}

/*

*   Function: canGetPacket

*

*   Input:  none

*   Output: none

*   Pre-conditions: a call to canISR and an packet is available and banked to RXB0

*   Affects: Calls canParse() function in main for parsing received packet.

*   Depends: none.

*/

void canGetPacket()

{

        CAN_PACKET cp;

        //RXB0SIDH 28 27 26 25 24 23 22 21

        //RXB0SIDL 20 19 18 xx xx xx 17 16

        //RXB0EIDH 15 14 13 12 11 10 09 08

        //RXB0EIDL 07 06 05 04 03 02 01 00

        cp.type = ((RXB0SIDH&0xC)>>6);

        if (cp.type==ptBOOT)

        {

            cp.boot.type  = ((RXB0SIDH&0x38)>>3);

            cp.boot.offset= ((RXB0SIDH&0x7)<<5)+((RXB0SIDL&0xE0)>>3)+(RXB0SIDL&0x3);

            cp.boot.rid   = RXB0EIDH;

        }

        else

        {

            cp.pgm.class= ((RXB0SIDH&0x3C)>>2);

            cp.pgm.id   = (((WORD)RXB0SIDH&0x3)<<13)+(((WORD)RXB0SIDL&0xE0)<<5)+((RXB0SIDL&0x3)<<8)+RXB0EIDH;

        }

        cp.sid   = RXB0EIDL;

        // Data length

        cp.length=(RXB0DLCbits.DLC3<<3)+(RXB0DLCbits.DLC2<<2)+(RXB0DLCbits.DLC1<<1)+RXB0DLCbits.DLC0;

        // Data one bye one, for speed

        cp.data[0]=RXB0D0;  cp.data[1]=RXB0D1;

        cp.data[2]=RXB0D2;  cp.data[3]=RXB0D3;

        cp.data[4]=RXB0D4;  cp.data[5]=RXB0D5;

        cp.data[6]=RXB0D6;  cp.data[7]=RXB0D7;

        // Clear ful status

        RXB0CONbits.RXFUL=0;

        // Check if bootloader request specific.

        // reset and id change

        if (cp.type==ptBOOT)

        {

            if (cp.boot.rid==MY_ID)

            {

                if (cp.boot.type==btADDR) Reset(); // Reset me.

                if (cp.boot.type==btCHANGEID)

                {

                        // Change my ID and NID

                        MY_ID=cp.data[0];

                        EEWrite(NODE_ID_EE+1,cp.data[0]);

                        EEWrite(NODE_ID_EE,NODE_HAS_ID);

                        // Send ack with new id.

                        outCp.type=ptBOOT;

                        outCp.boot.type=btACK;

                        outCp.length=0;

                        while(!canSendMessage(outCp,PRIO_HIGH));

                }

            }

        }

        //Call main parser

        if (cp.type==ptPGM) canParse(cp);

}

/*

*   Function: canSendMessage

*

*   Input:  CAN_MESSAGE to send

*   Output: True if packet scheduled sucess, false otherwise.

*   Pre-conditions: canInit

*   Affects: ..

*   Depends: ..

*/

BOOL canSendMessage(CAN_PACKET cp, CAN_PRIORITY prio)

{

    if ( TXB0CONbits.TXREQ == 0 )  { ECANCON=(ECANCON&0b00000)|0b00011; }

    if ( TXB1CONbits.TXREQ == 0 )  { ECANCON=(ECANCON&0b00000)|0b00100; }

    if ( TXB2CONbits.TXREQ == 0 )  { ECANCON=(ECANCON&0b00000)|0b00101; }

    // None of the transmit buffers were empty. 

    else { return FALSE;}

    if (prio<0 || prio>3) prio = 0;

    //RXB0SIDH 28 27 26 25 24 23 22 21

    //RXB0SIDL 20 19 18 xx xx xx 17 16

    //RXB0EIDH 15 14 13 12 11 10 09 08

    //RXB0EIDL 07 06 05 04 03 02 01 00

    if (cp.type==ptBOOT)

    {

        RXB0SIDH = ((cp.type&0x3)<<6)+((cp.boot.type&0x7)<<3)+((cp.boot.offset&0xE0)>>5);

        RXB0SIDL = ((cp.boot.offset&0x1C)<<3)+(cp.boot.offset&0x3);

        RXB0EIDH = cp.boot.rid;

    }

    else

    {

        RXB0SIDH = ((cp.type&0x3)<<6)+((cp.pgm.class&0xF)<<2)+((cp.pgm.id&0x6000)>>13);

        RXB0SIDL = ((cp.pgm.id&0x1C00)>>5)+((cp.pgm.id&0x300)>>8);

        RXB0EIDH = (cp.pgm.id&0xFF);

    }

    RXB0EIDL = MY_ID;

    // Data length

    RXB0DLC = 0;

    if (cp.length>8) RXB0DLC=8; else RXB0DLC=cp.length;

    // NOT Remote request

    _asm

        bcf RXB0DLC, 6, 0

    _endasm

    // Data one bye one, for speed

    RXB0D0=cp.data[0];  RXB0D1=cp.data[1];

    RXB0D2=cp.data[2];  RXB0D3=cp.data[3];

    RXB0D4=cp.data[4];  RXB0D5=cp.data[5];

    RXB0D6=cp.data[6];  RXB0D7=cp.data[7];

    // set extended

    RXB0SIDLbits.EXID=1;

    // Priority

    RXB0CON = (RXB0CON & 0b11111100) | prio;

    // mark as redy to transmit

    _asm

        bsf RXB0CON, 3, 0

    _endasm

    return TRUE;

}