u-boot/cpu/ixp/timer.c

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/*
* (C) Copyright 2006
* Stefan Roese, DENX Software Engineering, sr@denx.de.
*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Marius Groeger <mgroeger@sysgo.de>
*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Alex Zuepke <azu@sysgo.de>
*
* 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/ixp425.h>
#ifdef CONFIG_TIMER_IRQ
#define FREQ 66666666
#define CLOCK_TICK_RATE (((FREQ / CONFIG_SYS_HZ & ~IXP425_OST_RELOAD_MASK) + 1) * CONFIG_SYS_HZ)
#define LATCH ((CLOCK_TICK_RATE + CONFIG_SYS_HZ/2) / CONFIG_SYS_HZ) /* For divider */
/*
* When interrupts are enabled, use timer 2 for time/delay generation...
*/
static volatile ulong timestamp;
static void timer_isr(void *data)
{
unsigned int *pTime = (unsigned int *)data;
(*pTime)++;
/*
* Reset IRQ source
*/
*IXP425_OSST = IXP425_OSST_TIMER_2_PEND;
}
ulong get_timer (ulong base)
{
return timestamp - base;
}
void reset_timer (void)
{
timestamp = 0;
}
int timer_init (void)
{
/* install interrupt handler for timer */
irq_install_handler(IXP425_TIMER_2_IRQ, timer_isr, (void *)&timestamp);
/* setup the Timer counter value */
*IXP425_OSRT2 = (LATCH & ~IXP425_OST_RELOAD_MASK) | IXP425_OST_ENABLE;
/* enable timer irq */
*IXP425_ICMR = (1 << IXP425_TIMER_2_IRQ);
return 0;
}
#else
ulong get_timer (ulong base)
{
return get_timer_masked () - base;
}
void ixp425_udelay(unsigned long usec)
{
/*
* This function has a max usec, but since it is called from udelay
* we should not have to worry... be happy
*/
unsigned long usecs = CONFIG_SYS_HZ/1000000L & ~IXP425_OST_RELOAD_MASK;
*IXP425_OSST = IXP425_OSST_TIMER_1_PEND;
usecs |= IXP425_OST_ONE_SHOT | IXP425_OST_ENABLE;
*IXP425_OSRT1 = usecs;
while (!(*IXP425_OSST & IXP425_OSST_TIMER_1_PEND));
}
void udelay (unsigned long usec)
{
while (usec--) ixp425_udelay(1);
}
static ulong reload_constant = 0xfffffff0;
void reset_timer_masked (void)
{
ulong reload = reload_constant | IXP425_OST_ONE_SHOT | IXP425_OST_ENABLE;
*IXP425_OSST = IXP425_OSST_TIMER_1_PEND;
*IXP425_OSRT1 = reload;
}
ulong get_timer_masked (void)
{
/*
* Note that it is possible for this to wrap!
* In this case we return max.
*/
ulong current = *IXP425_OST1;
if (*IXP425_OSST & IXP425_OSST_TIMER_1_PEND)
{
return reload_constant;
}
return (reload_constant - current);
}
int timer_init(void)
{
return 0;
}
#endif