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/*
 * (C) Copyright 2007
 * Sascha Hauer, Pengutronix
 *
 * (C) Copyright 2009 Freescale Semiconductor
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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 (at your option) 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., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <common.h>
#include <asm/arch/mx25-regs.h>

#define TIMER_BASE 0x53f90000 /* General purpose timer 1 */

/* General purpose timers registers */
#define GPTCR	__REG(TIMER_BASE) /* Control register */
#define GPTPR	__REG(TIMER_BASE + 0x4) /* Prescaler register */
#define GPTSR	__REG(TIMER_BASE + 0x8) /* Status register */
#define GPTCNT	__REG(TIMER_BASE + 0x24) /* Counter register */

/* General purpose timers bitfields */
#define GPTCR_SWR	(1<<15) /* Software reset */
#define GPTCR_FRR	(1<<9)  /* Freerun / restart */
#define GPTCR_CLKSOURCE_32	(4<<6)  /* Clock source */
#define GPTCR_TEN	(1)	/* Timer enable */

static ulong timestamp;
static ulong lastinc;

/* nothing really to do with interrupts, just starts up a counter. */
int interrupt_init(void)
{
	int i;

	/* setup GP Timer 1 */
	GPTCR = GPTCR_SWR;
	for (i = 0; i < 100; i++)
		GPTCR = 0; /* We have no udelay by now */
	GPTPR = 0; /* 32Khz */
	GPTCR |= GPTCR_CLKSOURCE_32 | GPTCR_TEN; /* Freerun Mode, PERCLK1 in */

	return 0;
}

void reset_timer_masked(void)
{
	/* reset time */
	lastinc = GPTCNT; /* capture current incrementer value time */
	timestamp = 0; /* start "advancing" time stamp from 0 */
}

void reset_timer(void)
{
	reset_timer_masked();
}

ulong get_timer_masked(void)
{
	ulong now = GPTCNT; /* current tick value */

	if (now >= lastinc)	/* normal mode (non roll) */
		/* move stamp forward with absolut diff ticks */
		timestamp += (now - lastinc);
	else			/* we have rollover of incrementer */
		timestamp += (0xFFFFFFFF - lastinc) + now;
	lastinc = now;
	return timestamp;
}

ulong get_timer(ulong base)
{
	return get_timer_masked() - base;
}

void set_timer(ulong t)
{
}

/* delay x useconds AND perserve advance timstamp value */
void udelay(unsigned long usec)
{
	ulong tmo, tmp;

	if (usec >= 1000) {	/* if "big" number, spread normalize to secs */
		tmo = usec / 1000;	/* normalize usec to ticks per sec */
		tmo *= CONFIG_SYS_HZ;	/* find number of "ticks" to wait */
		tmo /= 1000;		/* finish normalize. */
	} else {			/* don't kill prior to HZ multiply */
		tmo = usec * CONFIG_SYS_HZ;
		tmo /= (1000*1000);
	}

	tmp = get_timer(0);		/* get current timestamp */
	if ((tmo + tmp + 1) < tmp)	/* if overflow time stamp */
		reset_timer_masked();	/* reset "advancing" timestamp to 0 */
	else
		tmo += tmp;		/* else, set stamp wake up time */
	while (get_timer_masked() < tmo)/* loop till event */
		/*NOP*/;
}

void reset_cpu(ulong addr)
{
	__REG16(WDOG_BASE) = 4;
}