src/drivers/pc80/i8254.c

/*
 * This file is part of the coreboot project.
 *
 * Copyright (C) 2009 coresystems GmbH
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <arch/io.h>
#include <pc80/i8254.h>
#include <console/console.h>

/* Initialize i8254 timers */

void setup_i8254(void)
{
	/* Timer 0 (taken from biosemu) */
	outb(TIMER0_SEL|WORD_ACCESS|MODE3|BINARY_COUNT, TIMER_MODE_PORT);
	outb(0x00, TIMER0_PORT);
	outb(0x00, TIMER0_PORT);

	/* Timer 1 */
	outb(TIMER1_SEL|LOBYTE_ACCESS|MODE3|BINARY_COUNT, TIMER_MODE_PORT);
	outb(0x12, TIMER1_PORT);
}

#if CONFIG_UDELAY_TIMER2
static void load_timer2(unsigned int ticks)
{
        /* Set up the timer gate, turn off the speaker */
        outb((inb(PPC_PORTB) & ~PPCB_SPKR) | PPCB_T2GATE, PPC_PORTB);
        outb(TIMER2_SEL|WORD_ACCESS|MODE0|BINARY_COUNT, TIMER_MODE_PORT);
        outb(ticks & 0xFF, TIMER2_PORT);
        outb(ticks >> 8, TIMER2_PORT);
}


void udelay(int usecs)
{
        load_timer2((usecs*TICKS_PER_MS)/1000);
        while ((inb(PPC_PORTB) & PPCB_T2OUT) == 0)
                ;
}
#endif