enc28j60.c

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/*! \file enc28j60.c \brief Microchip ENC28J60 Ethernet Interface Driver. */
//*****************************************************************************
//
// File Name    : 'enc28j60.c'
// Title        : Microchip ENC28J60 Ethernet Interface Driver
// Author       : Pascal Stang (c)2005
// Created      : 9/22/2005
// Revised      : 9/22/2005
// Version      : 0.1
// Target MCU   : Atmel AVR series
// Editor Tabs  : 4
//
// Description  : This driver provides initialization and transmit/receive
//  functions for the Microchip ENC28J60 10Mb Ethernet Controller and PHY.
// This chip is novel in that it is a full MAC+PHY interface all in a 28-pin
// chip, using an SPI interface to the host processor.
//
//*****************************************************************************

#include "global.h"
#include "timer.h"
#include "rprintf.h"

#include "enc28j60.h"

// include configuration
//#include "ax88796conf.h"

u08 Enc28j60Bank;
u16 NextPacketPtr;

void nicInit(void)
{
    enc28j60Init();
}

void nicSend(unsigned int len, unsigned char* packet)
{
    enc28j60PacketSend(len, packet);
}

unsigned int nicPoll(unsigned int maxlen, unsigned char* packet)
{
    return enc28j60PacketReceive(maxlen, packet);
}

void nicGetMacAddress(u08* macaddr)
{
    // read MAC address registers
    // NOTE: MAC address in ENC28J60 is byte-backward
    *macaddr++ = enc28j60Read(MAADR5);
    *macaddr++ = enc28j60Read(MAADR4);
    *macaddr++ = enc28j60Read(MAADR3);
    *macaddr++ = enc28j60Read(MAADR2);
    *macaddr++ = enc28j60Read(MAADR1);
    *macaddr++ = enc28j60Read(MAADR0);
}

void nicSetMacAddress(u08* macaddr)
{
    // write MAC address
    // NOTE: MAC address in ENC28J60 is byte-backward
    enc28j60Write(MAADR5, *macaddr++);
    enc28j60Write(MAADR4, *macaddr++);
    enc28j60Write(MAADR3, *macaddr++);
    enc28j60Write(MAADR2, *macaddr++);
    enc28j60Write(MAADR1, *macaddr++);
    enc28j60Write(MAADR0, *macaddr++);
}

void nicRegDump(void)
{
    enc28j60RegDump();
}

/*
void ax88796SetupPorts(void)
{
#if NIC_CONNECTION == MEMORY_MAPPED
    // enable external SRAM interface - no wait states
    sbi(MCUCR, SRE);
//  sbi(MCUCR, SRW10);
//  sbi(XMCRA, SRW00);
//  sbi(XMCRA, SRW01);
//  sbi(XMCRA, SRW11);
#else
    // set address port to output
    AX88796_ADDRESS_DDR = AX88796_ADDRESS_MASK;
    
    // set data port to input with pull-ups
    AX88796_DATA_DDR = 0x00;
    AX88796_DATA_PORT = 0xFF;

    // initialize the control port read and write pins to de-asserted
    sbi( AX88796_CONTROL_PORT, AX88796_CONTROL_READPIN );
    sbi( AX88796_CONTROL_PORT, AX88796_CONTROL_WRITEPIN );
    // set the read and write pins to output
    sbi( AX88796_CONTROL_DDR, AX88796_CONTROL_READPIN );
    sbi( AX88796_CONTROL_DDR, AX88796_CONTROL_WRITEPIN );
#endif
    // set reset pin to output
    sbi( AX88796_RESET_DDR, AX88796_RESET_PIN );
}
*/

u08 enc28j60ReadOp(u08 op, u08 address)
{
    u08 data;
   
    // assert CS
    ENC28J60_CONTROL_PORT &= ~(1<<ENC28J60_CONTROL_CS);
    
    // issue read command
    SPDR = op | (address & ADDR_MASK);
    while(!(SPSR & (1<<SPIF)));
    // read data
    SPDR = 0x00;
    while(!(SPSR & (1<<SPIF)));
    // do dummy read if needed
    if(address & 0x80)
    {
        SPDR = 0x00;
        while(!(inb(SPSR) & (1<<SPIF)));
    }
    data = SPDR;
    
    // release CS
    ENC28J60_CONTROL_PORT |= (1<<ENC28J60_CONTROL_CS);

    return data;
}

void enc28j60WriteOp(u08 op, u08 address, u08 data)
{
    // assert CS
    ENC28J60_CONTROL_PORT &= ~(1<<ENC28J60_CONTROL_CS);

    // issue write command
    SPDR = op | (address & ADDR_MASK);
    while(!(SPSR & (1<<SPIF)));
    // write data
    SPDR = data;
    while(!(SPSR & (1<<SPIF)));

    // release CS
    ENC28J60_CONTROL_PORT |= (1<<ENC28J60_CONTROL_CS);
}

void enc28j60ReadBuffer(u16 len, u08* data)
{
    // assert CS
    ENC28J60_CONTROL_PORT &= ~(1<<ENC28J60_CONTROL_CS);
    
    // issue read command
    SPDR = ENC28J60_READ_BUF_MEM;
    while(!(SPSR & (1<<SPIF)));
    while(len--)
    {
        // read data
        SPDR = 0x00;
        while(!(SPSR & (1<<SPIF)));
        *data++ = SPDR;
    }   
    // release CS
    ENC28J60_CONTROL_PORT |= (1<<ENC28J60_CONTROL_CS);
}

void enc28j60WriteBuffer(u16 len, u08* data)
{
    // assert CS
    ENC28J60_CONTROL_PORT &= ~(1<<ENC28J60_CONTROL_CS);
    
    // issue write command
    SPDR = ENC28J60_WRITE_BUF_MEM;
    while(!(SPSR & (1<<SPIF)));
    while(len--)
    {
        // write data
        SPDR = *data++;
        while(!(SPSR & (1<<SPIF)));
    }   
    // release CS
    ENC28J60_CONTROL_PORT |= (1<<ENC28J60_CONTROL_CS);
}

void enc28j60SetBank(u08 address)
{
    // set the bank (if needed)
    if((address & BANK_MASK) != Enc28j60Bank)
    {
        // set the bank
        enc28j60WriteOp(ENC28J60_BIT_FIELD_CLR, ECON1, (ECON1_BSEL1|ECON1_BSEL0));
        enc28j60WriteOp(ENC28J60_BIT_FIELD_SET, ECON1, (address & BANK_MASK)>>5);
        Enc28j60Bank = (address & BANK_MASK);
    }
}

u08 enc28j60Read(u08 address)
{
    // set the bank
    enc28j60SetBank(address);
    // do the read
    return enc28j60ReadOp(ENC28J60_READ_CTRL_REG, address);
}

void enc28j60Write(u08 address, u08 data)
{
    // set the bank
    enc28j60SetBank(address);
    // do the write
    enc28j60WriteOp(ENC28J60_WRITE_CTRL_REG, address, data);
}

u16 enc28j60PhyRead(u08 address)
{
    u16 data;

    // Set the right address and start the register read operation
    enc28j60Write(MIREGADR, address);
    enc28j60Write(MICMD, MICMD_MIIRD);

    // wait until the PHY read completes
    while(enc28j60Read(MISTAT) & MISTAT_BUSY);

    // quit reading
    enc28j60Write(MICMD, 0x00);
    
    // get data value
    data  = enc28j60Read(MIRDL);
    data |= enc28j60Read(MIRDH);
    // return the data
    return data;
}

void enc28j60PhyWrite(u08 address, u16 data)
{
    // set the PHY register address
    enc28j60Write(MIREGADR, address);
    
    // write the PHY data
    enc28j60Write(MIWRL, data); 
    enc28j60Write(MIWRH, data>>8);

    // wait until the PHY write completes
    while(enc28j60Read(MISTAT) & MISTAT_BUSY);
}

void enc28j60Init(void)
{
    // initialize I/O
    sbi(ENC28J60_CONTROL_DDR, ENC28J60_CONTROL_CS);
    sbi(ENC28J60_CONTROL_PORT, ENC28J60_CONTROL_CS);

    // setup SPI I/O pins
    sbi(PORTB, 1);  // set SCK hi
    sbi(DDRB, 1);   // set SCK as output
    cbi(DDRB, 3);   // set MISO as input
    sbi(DDRB, 2);   // set MOSI as output
    sbi(DDRB, 0);   // SS must be output for Master mode to work
    // initialize SPI interface
    // master mode
    sbi(SPCR, MSTR);
    // select clock phase positive-going in middle of data
    cbi(SPCR, CPOL);
    // Data order MSB first
    cbi(SPCR,DORD);
    // switch to f/4 2X = f/2 bitrate
    cbi(SPCR, SPR0);
    cbi(SPCR, SPR1);
    sbi(SPSR, SPI2X);
    // enable SPI
    sbi(SPCR, SPE);

    // perform system reset
    enc28j60WriteOp(ENC28J60_SOFT_RESET, 0, ENC28J60_SOFT_RESET);
    // check CLKRDY bit to see if reset is complete
    delay_us(50);
    while(!(enc28j60Read(ESTAT) & ESTAT_CLKRDY));

    // do bank 0 stuff
    // initialize receive buffer
    // 16-bit transfers, must write low byte first
    // set receive buffer start address
    NextPacketPtr = RXSTART_INIT;
    enc28j60Write(ERXSTL, RXSTART_INIT&0xFF);
    enc28j60Write(ERXSTH, RXSTART_INIT>>8);
    // set receive pointer address
    enc28j60Write(ERXRDPTL, RXSTART_INIT&0xFF);
    enc28j60Write(ERXRDPTH, RXSTART_INIT>>8);
    // set receive buffer end
    // ERXND defaults to 0x1FFF (end of ram)
    enc28j60Write(ERXNDL, RXSTOP_INIT&0xFF);
    enc28j60Write(ERXNDH, RXSTOP_INIT>>8);
    // set transmit buffer start
    // ETXST defaults to 0x0000 (beginnging of ram)
    enc28j60Write(ETXSTL, TXSTART_INIT&0xFF);
    enc28j60Write(ETXSTH, TXSTART_INIT>>8);

    // do bank 2 stuff
    // enable MAC receive
    enc28j60Write(MACON1, MACON1_MARXEN|MACON1_TXPAUS|MACON1_RXPAUS);
    // bring MAC out of reset
    enc28j60Write(MACON2, 0x00);
    // enable automatic padding and CRC operations
    enc28j60WriteOp(ENC28J60_BIT_FIELD_SET, MACON3, MACON3_PADCFG0|MACON3_TXCRCEN|MACON3_FRMLNEN);
//  enc28j60Write(MACON3, MACON3_PADCFG0|MACON3_TXCRCEN|MACON3_FRMLNEN);
    // set inter-frame gap (non-back-to-back)
    enc28j60Write(MAIPGL, 0x12);
    enc28j60Write(MAIPGH, 0x0C);
    // set inter-frame gap (back-to-back)
    enc28j60Write(MABBIPG, 0x12);
    // Set the maximum packet size which the controller will accept
    enc28j60Write(MAMXFLL, MAX_FRAMELEN&0xFF);  
    enc28j60Write(MAMXFLH, MAX_FRAMELEN>>8);

    // do bank 3 stuff
    // write MAC address
    // NOTE: MAC address in ENC28J60 is byte-backward
    enc28j60Write(MAADR5, ENC28J60_MAC0);
    enc28j60Write(MAADR4, ENC28J60_MAC1);
    enc28j60Write(MAADR3, ENC28J60_MAC2);
    enc28j60Write(MAADR2, ENC28J60_MAC3);
    enc28j60Write(MAADR1, ENC28J60_MAC4);
    enc28j60Write(MAADR0, ENC28J60_MAC5);

    // no loopback of transmitted frames
    enc28j60PhyWrite(PHCON2, PHCON2_HDLDIS);

    // switch to bank 0
    enc28j60SetBank(ECON1);
    // enable interrutps
    enc28j60WriteOp(ENC28J60_BIT_FIELD_SET, EIE, EIE_INTIE|EIE_PKTIE);
    // enable packet reception
    enc28j60WriteOp(ENC28J60_BIT_FIELD_SET, ECON1, ECON1_RXEN);
/*
    enc28j60PhyWrite(PHLCON, 0x0AA2);

    // setup duplex ----------------------

    // Disable receive logic and abort any packets currently being transmitted
    enc28j60WriteOp(ENC28J60_BIT_FIELD_CLR, ECON1, ECON1_TXRTS|ECON1_RXEN);
    
    {
        u16 temp;
        // Set the PHY to the proper duplex mode
        temp = enc28j60PhyRead(PHCON1);
        temp &= ~PHCON1_PDPXMD;
        enc28j60PhyWrite(PHCON1, temp);
        // Set the MAC to the proper duplex mode
        temp = enc28j60Read(MACON3);
        temp &= ~MACON3_FULDPX;
        enc28j60Write(MACON3, temp);
    }

    // Set the back-to-back inter-packet gap time to IEEE specified 
    // requirements.  The meaning of the MABBIPG value changes with the duplex
    // state, so it must be updated in this function.
    // In full duplex, 0x15 represents 9.6us; 0x12 is 9.6us in half duplex
    //enc28j60Write(MABBIPG, DuplexState ? 0x15 : 0x12);    
    
    // Reenable receive logic
    enc28j60WriteOp(ENC28J60_BIT_FIELD_SET, ECON1, ECON1_RXEN);

    // setup duplex ----------------------
*/
}

void enc28j60PacketSend(unsigned int len, unsigned char* packet)
{
    // Set the write pointer to start of transmit buffer area
    enc28j60Write(EWRPTL, TXSTART_INIT);
    enc28j60Write(EWRPTH, TXSTART_INIT>>8);
    // Set the TXND pointer to correspond to the packet size given
    enc28j60Write(ETXNDL, (TXSTART_INIT+len));
    enc28j60Write(ETXNDH, (TXSTART_INIT+len)>>8);

    // write per-packet control byte
    enc28j60WriteOp(ENC28J60_WRITE_BUF_MEM, 0, 0x00);

    // copy the packet into the transmit buffer
    enc28j60WriteBuffer(len, packet);
    
    // send the contents of the transmit buffer onto the network
    enc28j60WriteOp(ENC28J60_BIT_FIELD_SET, ECON1, ECON1_TXRTS);
}

unsigned int enc28j60PacketReceive(unsigned int maxlen, unsigned char* packet)
{
    u16 rxstat;
    u16 len;

    // check if a packet has been received and buffered
    if( !(enc28j60Read(EIR) & EIR_PKTIF) )
        return 0;
    
    // Make absolutely certain that any previous packet was discarded   
    //if( WasDiscarded == FALSE)
    //  MACDiscardRx();

    // Set the read pointer to the start of the received packet
    enc28j60Write(ERDPTL, (NextPacketPtr));
    enc28j60Write(ERDPTH, (NextPacketPtr)>>8);
    // read the next packet pointer
    NextPacketPtr  = enc28j60ReadOp(ENC28J60_READ_BUF_MEM, 0);
    NextPacketPtr |= enc28j60ReadOp(ENC28J60_READ_BUF_MEM, 0)<<8;
    // read the packet length
    len  = enc28j60ReadOp(ENC28J60_READ_BUF_MEM, 0);
    len |= enc28j60ReadOp(ENC28J60_READ_BUF_MEM, 0)<<8;
    // read the receive status
    rxstat  = enc28j60ReadOp(ENC28J60_READ_BUF_MEM, 0);
    rxstat |= enc28j60ReadOp(ENC28J60_READ_BUF_MEM, 0)<<8;

    // limit retrieve length
    // (we reduce the MAC-reported length by 4 to remove the CRC)
    len = MIN(len, maxlen);

    // copy the packet from the receive buffer
    enc28j60ReadBuffer(len, packet);

    // Move the RX read pointer to the start of the next received packet
    // This frees the memory we just read out
    enc28j60Write(ERXRDPTL, (NextPacketPtr));
    enc28j60Write(ERXRDPTH, (NextPacketPtr)>>8);

    // decrement the packet counter indicate we are done with this packet
    enc28j60WriteOp(ENC28J60_BIT_FIELD_SET, ECON2, ECON2_PKTDEC);

    return len;
}

void enc28j60ReceiveOverflowRecover(void)
{
    // receive buffer overflow handling procedure

    // recovery completed
}

void enc28j60RegDump(void)
{
//  unsigned char macaddr[6];
//  result = ax88796Read(TR);
    
//  rprintf("Media State: ");
//  if(!(result & AUTOD))
//      rprintf("Autonegotiation\r\n");
//  else if(result & RST_B)
//      rprintf("PHY in Reset   \r\n");
//  else if(!(result & RST_10B))
//      rprintf("10BASE-T       \r\n");
//  else if(!(result & RST_TXB))
//      rprintf("100BASE-T      \r\n");
                
    rprintf("RevID: 0x%x\r\n", enc28j60Read(EREVID));

    rprintfProgStrM("Cntrl: ECON1 ECON2 ESTAT  EIR  EIE\r\n");
    rprintfProgStrM("         ");
    rprintfu08(enc28j60Read(ECON1));
    rprintfProgStrM("    ");
    rprintfu08(enc28j60Read(ECON2));
    rprintfProgStrM("    ");
    rprintfu08(enc28j60Read(ESTAT));
    rprintfProgStrM("    ");
    rprintfu08(enc28j60Read(EIR));
    rprintfProgStrM("   ");
    rprintfu08(enc28j60Read(EIE));
    rprintfCRLF();

    rprintfProgStrM("MAC  : MACON1  MACON2  MACON3  MACON4  MAC-Address\r\n");
    rprintfProgStrM("        0x");
    rprintfu08(enc28j60Read(MACON1));
    rprintfProgStrM("    0x");
    rprintfu08(enc28j60Read(MACON2));
    rprintfProgStrM("    0x");
    rprintfu08(enc28j60Read(MACON3));
    rprintfProgStrM("    0x");
    rprintfu08(enc28j60Read(MACON4));
    rprintfProgStrM("   ");
    rprintfu08(enc28j60Read(MAADR5));
    rprintfu08(enc28j60Read(MAADR4));
    rprintfu08(enc28j60Read(MAADR3));
    rprintfu08(enc28j60Read(MAADR2));
    rprintfu08(enc28j60Read(MAADR1));
    rprintfu08(enc28j60Read(MAADR0));
    rprintfCRLF();

    rprintfProgStrM("Rx   : ERXST  ERXND  ERXWRPT ERXRDPT ERXFCON EPKTCNT MAMXFL\r\n");
    rprintfProgStrM("       0x");
    rprintfu08(enc28j60Read(ERXSTH));
    rprintfu08(enc28j60Read(ERXSTL));
    rprintfProgStrM(" 0x");
    rprintfu08(enc28j60Read(ERXNDH));
    rprintfu08(enc28j60Read(ERXNDL));
    rprintfProgStrM("  0x");
    rprintfu08(enc28j60Read(ERXWRPTH));
    rprintfu08(enc28j60Read(ERXWRPTL));
    rprintfProgStrM("  0x");
    rprintfu08(enc28j60Read(ERXRDPTH));
    rprintfu08(enc28j60Read(ERXRDPTL));
    rprintfProgStrM("   0x");
    rprintfu08(enc28j60Read(ERXFCON));
    rprintfProgStrM("    0x");
    rprintfu08(enc28j60Read(EPKTCNT));
    rprintfProgStrM("  0x");
    rprintfu08(enc28j60Read(MAMXFLH));
    rprintfu08(enc28j60Read(MAMXFLL));
    rprintfCRLF();

    rprintfProgStrM("Tx   : ETXST  ETXND  MACLCON1 MACLCON2 MAPHSUP\r\n");
    rprintfProgStrM("       0x");
    rprintfu08(enc28j60Read(ETXSTH));
    rprintfu08(enc28j60Read(ETXSTL));
    rprintfProgStrM(" 0x");
    rprintfu08(enc28j60Read(ETXNDH));
    rprintfu08(enc28j60Read(ETXNDL));
    rprintfProgStrM("   0x");
    rprintfu08(enc28j60Read(MACLCON1));
    rprintfProgStrM("     0x");
    rprintfu08(enc28j60Read(MACLCON2));
    rprintfProgStrM("     0x");
    rprintfu08(enc28j60Read(MAPHSUP));
    rprintfCRLF();

    delay_ms(25);
}

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