/*
 * Program to write MAC info and defaults into EEPROM of Intel eepro100
 * ethernet controller
 *
 * Moshen Chan <mchan@cobalt.com>
 * May 19, 2000
 */

#include <stdio.h>
#include <sys/io.h>

#include "enet_eeprom.h"

/*  EEPROM_Ctrl bit masks. */
#define EE_SHIFT_CLK   	0x01	/* EEPROM shift clock. */
#define EE_CS	       	0x02	/* EEPROM chip select. */
#define EE_DATA_WRITE	0x04	/* EEPROM chip data in. */
#define EE_DATA_READ	0x08	/* EEPROM chip data out. */
#define EE_ENB	       	(0x4800 | EE_CS)
#define EE_WRITE_0     	0x4802
#define EE_WRITE_1     	0x4806
#define EE_OFFSET      	0x0E

/* these are the opcodes for the EEPROM, shifted by an amount to */
/* leave room for the address and data fields. */
#define EE_READ_CMD     (6 << 22)
#define EE_WRITE_CMD    (5 << 22)
#define EE_ENABLE_OPCODE (4 << 22)

#define EE_SIZE         64

/* eeprom data - fixed values come from Intel spec */
unsigned short eeprom_default_data[] = {
    0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0101, 0x4701, 0x0000,
    0x3525, 0x0903, 0x0000, 0x0000, 0x108e, 0x0000, 0x0000, 0x0000,
    0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
    0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
    0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
    0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
    0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
    0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000
};



/* static functions */
static void eeprom_delay(unsigned short ioaddr);
static int do_eeprom_cmd(unsigned short ioaddr, int cmd, int cmd_len);
static unsigned short read_ee_word(unsigned short ioaddr, int offset);
static void write_ee_word(unsigned short ioaddr, int offset, unsigned short word);

static int eepro100_read_eeprom(unsigned short ioaddr, unsigned short *eeprom);
static int eepro100_write_eeprom(unsigned short ioaddr, unsigned short *eeprom);
static int eepro100_read_byte(unsigned short ioaddr, unsigned char *data, int offset);
static int eepro100_read_word(unsigned short ioaddr, unsigned short *data, int offset);
static int eepro100_write_byte(unsigned short ioaddr, unsigned char data, int offset);
static int eepro100_write_word(unsigned short ioaddr, unsigned short data, int offset);
static int eepro100_update_checksum(unsigned short *eeprom);
static int eepro100_get_size( void );
static int eepro100_read_mac(unsigned short *eeprom, unsigned char *mac_data);
static int eepro100_write_mac(unsigned short *eeprom, unsigned char *mac);
static int eepro100_load_default( unsigned short *eeprom );

static void eeprom_delay(unsigned short ioaddr) {
    int i;
    for (i=0; i<500; i++) 
	inw(ioaddr + EE_OFFSET);
}

static int do_eeprom_cmd(unsigned short ioaddr, int cmd, int cmd_len) {
    unsigned retval = 0;
    short dataval;
    int ee_addr = ioaddr + EE_OFFSET;
    
    outw(EE_ENB | EE_SHIFT_CLK, ee_addr);

    /* Shift the command bits out. */
    do {
       /*  write bit 1 or 0 to register? */
	if (cmd & (1 << cmd_len))
	    dataval = EE_WRITE_1;
	else
	    dataval = EE_WRITE_0;
	
	outw(dataval, ee_addr);
	eeprom_delay(ioaddr);
	/* shift clock */
	outw(dataval | EE_SHIFT_CLK, ee_addr);
	eeprom_delay(ioaddr);
	/* get data from register, take a 1 or 0 from EE_DATA_READ bit */
	retval = (retval << 1) | ((inw(ee_addr) & EE_DATA_READ) ? 1 : 0);
    } while (--cmd_len >= 0);
    outw(EE_ENB, ee_addr);
    
    /* Terminate the EEPROM access. */
    outw(EE_ENB & ~EE_CS, ee_addr);
    return retval;
}

/* read 16 bit word at offset */
static unsigned short read_ee_word(unsigned short ioaddr, int offset) {
    unsigned short value;
    
    value = do_eeprom_cmd(ioaddr, EE_READ_CMD | (offset << 16), 25);
    return value;
}
    
/* write 16 bit word at offset */
static void write_ee_word(unsigned short ioaddr, int offset, unsigned short word) {
    /* enable eeprom writes */
    do_eeprom_cmd(ioaddr, (EE_ENABLE_OPCODE | ((short)48 << 16)), 27);
    
    do_eeprom_cmd(ioaddr, (EE_WRITE_CMD | (offset << 16)) | word, 27);
    /* disable eeprom writes */
    do_eeprom_cmd(ioaddr, (EE_ENABLE_OPCODE | ((short)0 << 16)), 27);

}



static int eepro100_read_eeprom(unsigned short ioaddr, unsigned short *eeprom) {
    int i;

    for (i=0; i<EE_SIZE; i++) {
	eepro100_read_word(ioaddr, &eeprom[i], i);
    }
    return 0;
}

static int eepro100_write_eeprom(unsigned short ioaddr, unsigned short *eeprom) {
    int i;

    for (i=0; i<EE_SIZE; i++) {
	if (eepro100_write_word(ioaddr, eeprom[i], i) < 0)
	    return -1;
    }
    return 0;
}


static int eepro100_read_byte(unsigned short ioaddr, unsigned char *data, int offset) {
    unsigned short value;

    if ((int) (offset /2) > (EE_SIZE - 1))
	return -1;

    value = read_ee_word(ioaddr, (int) (offset/2));
    if ((offset % 2) == 0)
	*data = (unsigned char) (value & 0xff);
    else
	*data = (unsigned char) (value >> 8);
    
    return 0;
}


static int eepro100_read_word(unsigned short ioaddr, unsigned short *data, int offset) {
    
    if (offset > (EE_SIZE - 1))
	return -1;
    *data = read_ee_word(ioaddr, offset);
    
    return 0;
}

static int eepro100_write_byte(unsigned short ioaddr, unsigned char data, int offset) {
    unsigned short value;
    int wordoffset;

    wordoffset = (int) offset/2;

    if (wordoffset > (EE_SIZE - 1))
	return -1;

    value = read_ee_word(ioaddr, wordoffset);
    if ((offset % 2) == 0) {
	write_ee_word(ioaddr, wordoffset, (value & 0xff00) | data);
	/* verify */
	if (read_ee_word(ioaddr, wordoffset) != ((value & 0xff00) | data))
	    return -1;
    }
    else {
	write_ee_word(ioaddr, wordoffset, (value & 0xff) | (data << 8)); 
	if (read_ee_word(ioaddr, wordoffset) != ((value & 0xff) | (data << 8)))
	    return -1;
    }
    return 0;
}
	    
static int eepro100_write_word(unsigned short ioaddr, unsigned short data, int offset) {
    if (offset > (EE_SIZE -1))
	return -1;
    write_ee_word(ioaddr, offset, data);
    /* verify */
    if (read_ee_word(ioaddr, offset) != data) 
	return -2;
    return 0;
}

    
static int eepro100_update_checksum(unsigned short *eeprom) {
    int i;
    unsigned short sum = 0;
    unsigned short checksum = 0;

    for (i=0; i<63; i++) {
	sum += eeprom[i];
    }

    checksum = 0xBABA - sum;
    checksum &= 0xFFFF;

    eeprom[63] = checksum;

    /* verify checksum */
    sum = 0;
    for (i=0; i<EE_SIZE; i++) {
	sum += eeprom[i];
    }
    if (sum == 0xBABA)
	return 0;
    else
	return -1;
}

/* get size of eeprom */
static int eepro100_get_size( void )
{
    return EE_SIZE;
}

static int eepro100_load_default( unsigned short *eeprom )
{
    int i;
    for( i=0 ; i<EE_SIZE ; i++ )
    {
	eeprom[i] = eeprom_default_data[i];
    }
    return 0;
}

static int eepro100_read_mac(unsigned short *eeprom, unsigned char *mac_data) 
{
    int i;
    
    for (i = 0; i<6; i++) 
	mac_data[i] = ((unsigned char *)eeprom)[i];
    
    return 0;
}

//FIXME: needs testing - upper level used to reverse bytes!! ??
static int eepro100_write_mac(unsigned short *eeprom, unsigned char *mac) {

    int i;
    
    /* write MAC */
    for (i = 0; i<6; i++) 
	((unsigned char *)eeprom)[i] = mac[i];
    
    return 0;
}

struct eeprom_driver eepro100_driver =
{
    eepro100_read_eeprom, /* read_eeprom */
    eepro100_write_eeprom, /* write_eeprom */
    eepro100_read_byte, /* read_byte */
    eepro100_read_word, /* read_word */
    eepro100_write_byte, /* write_byte */
    eepro100_write_word, /* write_word */
    eepro100_get_size, /* get_size */
    eepro100_update_checksum, /* update_checksum */
    eepro100_load_default, /* load_default */
    eepro100_read_mac, /* read_mac */
    eepro100_write_mac, /* write_mac */
    NULL, /* read_wol */
    NULL, /* write_wol */
    NULL, /* read_sopass */
    NULL /* write_sopass */
};