u-boot/cpu/mcf547x_8x/slicetimer.c
Ingo van Lil 3eb90bad65 Generic udelay() with watchdog support
According to the PPC reference implementation the udelay() function is
responsible for resetting the watchdog timer as frequently as needed.
Most other architectures do not meet that requirement, so long-running
operations might result in a watchdog reset.

This patch adds a generic udelay() function which takes care of
resetting the watchdog before calling an architecture-specific
__udelay().

Signed-off-by: Ingo van Lil <inguin@gmx.de>
2009-12-05 01:08:53 +01:00

112 lines
2.7 KiB
C

/*
* (C) Copyright 2007 Freescale Semiconductor, Inc.
* TsiChung Liew (Tsi-Chung.Liew@freescale.com)
*
* 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_SLTTMR)
#ifndef CONFIG_SYS_UDELAY_BASE
# error "uDelay base not defined!"
#endif
#if !defined(CONFIG_SYS_TMR_BASE) || !defined(CONFIG_SYS_INTR_BASE) || !defined(CONFIG_SYS_TMRINTR_NO) || !defined(CONFIG_SYS_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 slt_t *timerp = (slt_t *) (CONFIG_SYS_UDELAY_BASE);
u32 now, freq;
/* 1 us period */
freq = CONFIG_SYS_TIMER_PRESCALER;
timerp->cr = 0; /* Disable */
timerp->tcnt = usec * freq;
timerp->cr = SLT_CR_TEN;
now = timerp->cnt;
while (now != 0)
now = timerp->cnt;
timerp->sr |= SLT_SR_ST;
timerp->cr = 0;
}
void dtimer_interrupt(void *not_used)
{
volatile slt_t *timerp = (slt_t *) (CONFIG_SYS_TMR_BASE);
/* check for timer interrupt asserted */
if ((CONFIG_SYS_TMRPND_REG & CONFIG_SYS_TMRINTR_MASK) == CONFIG_SYS_TMRINTR_PEND) {
timerp->sr |= SLT_SR_ST;
timestamp++;
return;
}
}
void timer_init(void)
{
volatile slt_t *timerp = (slt_t *) (CONFIG_SYS_TMR_BASE);
timestamp = 0;
timerp->cr = 0; /* disable timer */
timerp->tcnt = 0;
timerp->sr = SLT_SR_BE | SLT_SR_ST; /* clear status */
/* initialize and enable timer interrupt */
irq_install_handler(CONFIG_SYS_TMRINTR_NO, dtimer_interrupt, 0);
/* Interrupt every ms */
timerp->tcnt = 1000 * CONFIG_SYS_TIMER_PRESCALER;
dtimer_intr_setup();
/* set a period of 1us, set timer mode to restart and
enable timer and interrupt */
timerp->cr = SLT_CR_RUN | SLT_CR_IEN | SLT_CR_TEN;
}
void reset_timer(void)
{
timestamp = 0;
}
ulong get_timer(ulong base)
{
return (timestamp - base);
}
void set_timer(ulong t)
{
timestamp = t;
}
#endif /* CONFIG_SLTTMR */