time.c

U-boot源码 ARM7启动代码

/*
 * (C) Copyright 2003 Josef Baumgartner <[e-mail]>
 *
 * (C) Copyright 2000
 * Wolfgang Denk, DENX Software Engineering, [e-mail].
 *
 * 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/timer.h>
#include <asm/immap.h>

DECLARE_GLOBAL_DATA_PTR;

static ulong timestamp;

#if defined(CONFIG_MCFTMR)
#ifndef CFG_UDELAY_BASE
#	error	"uDelay base not defined!"
#endif

#if !defined(CFG_TMR_BASE) || !defined(CFG_INTR_BASE) || !defined(CFG_TMRINTR_NO) || !defined(CFG_TMRINTR_MASK)
#	error	"TMR_BASE, INTR_BASE, TMRINTR_NO or TMRINTR_MASk not defined!"
#endif
extern void dtimer_intr_setup(void);

void udelay(unsigned long usec)
{
	volatile dtmr_t *timerp = (dtmr_t *) (CFG_UDELAY_BASE);
	uint start, now, tmp;

	while (usec > 0) {
		if (usec > 65000)
			tmp = 65000;
		else
			tmp = usec;
		usec = usec - tmp;

		/* Set up TIMER 3 as timebase clock */
		timerp->tmr = DTIM_DTMR_RST_RST;
		timerp->tcn = 0;
		/* set period to 1 us */
		timerp->tmr =
		    CFG_TIMER_PRESCALER | DTIM_DTMR_CLK_DIV1 | DTIM_DTMR_FRR |
		    DTIM_DTMR_RST_EN;

		start = now = timerp->tcn;
		while (now < start + tmp)
			now = timerp->tcn;
	}
}

void dtimer_interrupt(void *not_used)
{
	volatile dtmr_t *timerp = (dtmr_t *) (CFG_TMR_BASE);

	/* check for timer interrupt asserted */
	if ((CFG_TMRPND_REG & CFG_TMRINTR_MASK) == CFG_TMRINTR_PEND) {
		timerp->ter = (DTIM_DTER_CAP | DTIM_DTER_REF);
		timestamp++;
		return;
	}
}

void timer_init(void)
{
	volatile dtmr_t *timerp = (dtmr_t *) (CFG_TMR_BASE);

	timestamp = 0;

	timerp->tcn = 0;
	timerp->trr = 0;

	/* Set up TIMER 4 as clock */
	timerp->tmr = DTIM_DTMR_RST_RST;

	/* initialize and enable timer interrupt */
	irq_install_handler(CFG_TMRINTR_NO, dtimer_interrupt, 0);

	timerp->tcn = 0;
	timerp->trr = 1000;	/* Interrupt every ms */

	dtimer_intr_setup();

	/* set a period of 1us, set timer mode to restart and enable timer and interrupt */
	timerp->tmr = CFG_TIMER_PRESCALER | DTIM_DTMR_CLK_DIV1 |
	    DTIM_DTMR_FRR | DTIM_DTMR_ORRI | DTIM_DTMR_RST_EN;
}

void reset_timer(void)
{
	timestamp = 0;
}

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

void set_timer(ulong t)
{
	timestamp = t;
}
#endif				/* CONFIG_MCFTMR */

#if defined(CONFIG_MCFPIT)
#if !defined(CFG_PIT_BASE)
#	error	"CFG_PIT_BASE not defined!"
#endif

static unsigned short lastinc;

void udelay(unsigned long usec)
{
	volatile pit_t *timerp = (pit_t *) (CFG_UDELAY_BASE);
	uint tmp;

	while (usec > 0) {
		if (usec > 65000)
			tmp = 65000;
		else
			tmp = usec;
		usec = usec - tmp;

		/* Set up TIMER 3 as timebase clock */
		timerp->pcsr = PIT_PCSR_OVW;
		timerp->pmr = 0;
		/* set period to 1 us */
		timerp->pcsr |= PIT_PCSR_PRE(CFG_PIT_PRESCALE) | PIT_PCSR_EN;

		timerp->pmr = tmp;
		while (timerp->pcntr > 0) ;
	}
}

void timer_init(void)
{
	volatile pit_t *timerp = (pit_t *) (CFG_PIT_BASE);
	timestamp = 0;

	/* Set up TIMER 4 as poll clock */
	timerp->pcsr = PIT_PCSR_OVW;
	timerp->pmr = lastinc = 0;
	timerp->pcsr |= PIT_PCSR_PRE(CFG_PIT_PRESCALE) | PIT_PCSR_EN;
}

void set_timer(ulong t)
{
	volatile pit_t *timerp = (pit_t *) (CFG_PIT_BASE);

	timestamp = 0;
	timerp->pmr = lastinc = 0;
}

ulong get_timer(ulong base)
{
	unsigned short now, diff;
	volatile pit_t *timerp = (pit_t *) (CFG_PIT_BASE);

	now = timerp->pcntr;
	diff = -(now - lastinc);

	timestamp += diff;
	lastinc = now;
	return timestamp - base;
}

void wait_ticks(unsigned long ticks)
{
	set_timer(0);
	while (get_timer(0) < ticks) ;
}
#endif				/* CONFIG_MCFPIT */

/*
 * This function is derived from PowerPC code (read timebase as long long).
 * On M68K it just returns the timer value.
 */
unsigned long long get_ticks(void)
{
	return get_timer(0);
}

/*
 * This function is derived from PowerPC code (timebase clock frequency).
 * On M68K it returns the number of timer ticks per second.
 */
ulong get_tbclk(void)
{
	ulong tbclk;
	tbclk = CFG_HZ;
	return tbclk;
}