/*
 * core/timer.c
 *
 * Copyright (C) 2007 Alexey Zaytsev <alexey.zaytsev@gmail.com>
 *
 * 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; either version 2 of the
 * License, or any later version.
 *
 * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <stddef.h>
#include <assert.h>
#include <gpxe/init.h>
#include <gpxe/timer.h>
#include <stdio.h>

static struct timer ts_table[0]
	__table_start ( struct timer, timers );
static struct timer ts_table_end[0]
	__table_end ( struct timer, timers );


static struct timer *used_ts = NULL;

/*
 * This function may be used in custom timer driver.
 *
 * This udelay implementation works well if you've got a
 * fast currticks().
 */
void generic_currticks_udelay(unsigned int usecs)
{
	tick_t t;

	t = currticks();
	while (t + usecs > currticks())
		; /* xxx: Relax the cpu some way. */
}


static void timer_init(void)
{
	struct timer *ts;

	for (ts = ts_table; ts < ts_table_end; ts++) {
		if (ts->init && ts->init() >= 0) {
			used_ts = ts;
			break;
		}
	}

	assert(used_ts);
}

struct init_fn ts_init_fn __init_fn ( INIT_NORMAL ) = {
	.initialise = timer_init,
};

/* Functions for public use. */

tick_t currticks(void)
{
	tick_t ct;
	assert(used_ts);

	ct = used_ts->currticks();
	DBG("currticks: %ld seconds and %06ld microseconds\n", ct/USECS_IN_SEC, ct%USECS_IN_SEC);

	return ct;
}

void udelay(unsigned int usecs)
{
	used_ts->udelay(usecs);
}

void mdelay(unsigned int msecs)
{
	while(msecs--)
		used_ts->udelay(USECS_IN_MSEC);
}

unsigned int sleep(unsigned int secs)
{
	while (secs--)
		mdelay(MSECS_IN_SEC);

	return 0;
}