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/*
* (C) Copyright 2003
* Texas Instruments <www.ti.com>
*
* (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>
*
* (C) Copyright 2002-2004
* Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
*
* (C) Copyright 2004
* Philippe Robin, ARM Ltd. <philippe.robin@arm.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/io.h>
#include <arm926ejs.h>
#define TIMER_LOAD_VAL 0xffffffff
/* macro to read the 32 bit timer */
#define READ_TIMER readl(CONFIG_SYS_TIMERBASE + 20)
static ulong timestamp;
static ulong lastdec;
/* nothing really to do with interrupts, just starts up a counter. */
int timer_init(void)
{
/* Load timer with initial value */
writel(TIMER_LOAD_VAL, CONFIG_SYS_TIMERBASE + 16);
/*
* Set timer to be enabled, free-running, no interrupts, 256 divider,
* 32-bit, wrap-mode
*/
writel(0x8a, CONFIG_SYS_TIMERBASE + 24);
/* init the timestamp and lastdec value */
reset_timer_masked();
return 0;
}
/*
* timer without interrupts
*/
void reset_timer(void)
{
reset_timer_masked();
}
ulong get_timer(ulong base)
{
return get_timer_masked() - base;
}
void set_timer(ulong t)
{
timestamp = t;
}
/* delay x useconds AND perserve advance timstamp value */
void udelay(unsigned long usec)
{
ulong tmo, tmp;
if (usec >= 1000) {
/* if "big" number, spread normalization to seconds */
tmo = usec / 1000; /* start to normalize */
tmo *= CONFIG_SYS_HZ; /* find number of "ticks" */
tmo /= 1000; /* finish normalize. */
} else {
/* small number, don't kill it prior to HZ multiply */
tmo = usec * CONFIG_SYS_HZ;
tmo /= (1000 * 1000);
}
tmp = get_timer(0); /* get current timestamp */
if ((tmo + tmp + 1) < tmp) /* will roll time stamp? */
reset_timer_masked(); /* reset to 0, set lastdec value */
else
tmo += tmp;
while (get_timer_masked() < tmo)
/* nothing */ ;
}
void reset_timer_masked(void)
{
/* reset time */
lastdec = READ_TIMER; /* capure current decrementer value time */
timestamp = 0; /* start "advancing" time stamp from 0 */
}
ulong get_timer_masked(void)
{
ulong now = READ_TIMER; /* current tick value */
if (lastdec >= now) { /* normal mode (non roll) */
/* move stamp fordward */
timestamp += lastdec - now;
} else {
/*
* An overflow is expected.
* nts = ts + ld + (TLV - now)
* ts=old stamp, ld=time that passed before passing through -1
* (TLV-now) amount of time after passing though -1
* nts = new "advancing time stamp"...it could also roll
*/
timestamp += lastdec + TIMER_LOAD_VAL - now;
}
lastdec = now;
return timestamp;
}
/* waits specified delay value and resets timestamp */
void udelay_masked(unsigned long usec)
{
ulong tmo;
if (usec >= 1000) {
/* if "big" number, spread normalization to seconds */
tmo = usec / 1000; /* start to normalize */
tmo *= CONFIG_SYS_HZ; /* find number of "ticks" */
tmo /= 1000; /* finish normalize. */
} else {
/* else small number, don't kill it prior to HZ multiply */
tmo = usec * CONFIG_SYS_HZ;
tmo /= (1000*1000);
}
reset_timer_masked();
/* set "advancing" timestamp to 0, set lastdec vaule */
while (get_timer_masked() < tmo)
/* nothing */ ;
}
/*
* This function is derived from PowerPC code (read timebase as long long).
* On ARM 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 ARM it returns the number of timer ticks per second.
*/
ulong get_tbclk(void)
{
ulong tbclk;
tbclk = CONFIG_SYS_HZ;
return tbclk;
}
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