#include <asm/io.h>

#ifndef __KERNEL__
#include <stdio.h>
#include <unistd.h>

void winbond_probe(unsigned short port, unsigned char magic);

void main(void)
{
    if (iopl(3)) {
	fprintf(stderr, "Could not unlock IO ports. Are you superuser?\n");
	exit(1);
    }
    printf("Looking for a Winbond W83977\n");
    winbond_probe(0x3f0, 0x87);
    winbond_probe(0x370, 0x87);
}
#else
#include <linux/kernel.h>
#define printf printk
#endif

unsigned char read_reg(short p, char m, char d, char r)
{
    unsigned char tmp;

    outb(m, p);
    outb(m, p);
    outb(0x07, p);
    outb(d, p + 1);		/* Select this device */
    outb(r, p);
    tmp = inb(p + 1);		/* Read value */
    outb(0xaa, p);
    return tmp;
}

void write_reg(short p, char m, char d, char r, char x)
{
    outb(m, p);
    outb(m, p);
    outb(0x07, p);
    outb(d, p + 1);             /* Select this device */
    outb(r, p);
    outb(x, p + 1);		/* Write value */
    outb(0xaa, p);
}

void winbond_probe(unsigned short port, unsigned char magic)
{
    unsigned char hk, lk, da, rc, ha, la, pi, pd, pm;
    char *mode_ref[8] =
    {"PS2", "EPP(1.9)", "ECP", "ECP+EPP(1.9)",
     "SPP", "EPP(1.7)", "???", "ECP+EPP(1.7)"};

    hk = read_reg(port, magic, 0x00, 0x20);	/* High key */
    lk = read_reg(port, magic, 0x00, 0x21);	/* Low key */

    if ((hk == 0xff) && (lk == 0xff))
	return;
    printf("Winbond ID key = %02x%02x\n", hk, lk);

    da = read_reg(port, magic, 0x01, 0x30);	/* Device available */
    rc = read_reg(port, magic, 0x01, 0x31);	/* Port address range check */
    ha = read_reg(port, magic, 0x01, 0x60);	/* Port address - high byte */
    la = read_reg(port, magic, 0x01, 0x61);	/* Port address - low byte */
    pi = read_reg(port, magic, 0x01, 0x70);	/* Parallel port IRQ */
    pd = read_reg(port, magic, 0x01, 0x74);	/* Parallel port DMA */
    pm = read_reg(port, magic, 0x01, 0xf0);	/* Parallel port mode */

    printf("Parallel port enabled - %s\n", (da & 0x01) ? "YES" : "NO");
    printf("              address - %02x%02x\n", ha, la);
    printf("              IRQ     - %02x\n", pi & 0x07);
    if (pd > 3)
	printf("              DMA     - none\n");
    else
	printf("              DMA     - %02x\n", pd & 0x03);
    printf("              mode    - %s\n", mode_ref[pm & 0x07]);
    write_reg(port, magic, 0x01, 0xf0, 0x02);
}