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/*
* (C) Copyright 2004
* Texas Instruments
* Richard Woodruff <r-woodruff2@ti.com>
*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Marius Groeger <mgroeger@sysgo.de>
* Alex Zuepke <azu@sysgo.de>
*
* (C) Copyright 2002
* Gary Jennejohn, DENX Software Engineering, <garyj@denx.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/io.h>
#define TIMER_CLOCK (CONFIG_SYS_CLK_FREQ / (1 << (CONFIG_TIMER_PRESCALE * 4)))
#define TIMER_LOAD_VAL 0xFFFFFF
/* macro to read the 32 bit timer */
#define READ_TIMER (TIMER_LOAD_VAL - readl(CONFIG_SYS_TIMERBASE + TIMER_CURR)) \
/ (TIMER_CLOCK / CONFIG_SYS_HZ)
#define READ_TIMER_HW (TIMER_LOAD_VAL - readl(CONFIG_SYS_TIMERBASE + TIMER_CURR))
DECLARE_GLOBAL_DATA_PTR;
int timer_init (void)
{
int32_t val;
/* Start the counter ticking up */
writel(TIMER_LOAD_VAL, CONFIG_SYS_TIMERBASE + TIMER_LOAD); /* reload value on overflow*/
val = (CONFIG_TIMER_PRESCALE << TIMER_PRESCALE_SHIFT) |
(TIMER_MODE_PERIODIC << TIMER_MODE_SHIFT) |
(TIMER_ENABLE << TIMER_ENABLE_SHIFT); /* mask to enable timer*/
writel(val, CONFIG_SYS_TIMERBASE + TIMER_CTRL); /* start timer */
/* reset time */
gd->arch.lastinc = READ_TIMER; /* capture current incrementer value */
gd->arch.tbl = 0; /* start "advancing" time stamp */
return(0);
}
/*
* timer without interrupts
*/
ulong get_timer (ulong base)
{
return get_timer_masked () - base;
}
/* delay x useconds AND preserve advance timestamp value */
void __udelay (unsigned long usec)
{
ulong tmo, tmp;
if (usec > 100000) { /* if "big" number, spread normalization to seconds */
tmo = usec / 1000; /* start to normalize for usec to ticks per sec */
tmo *= CONFIG_SYS_HZ; /* find number of "ticks" to wait to achieve target */
tmo /= 1000; /* finish normalize. */
tmp = get_timer (0); /* get current timestamp */
while (get_timer (tmp) < tmo)/* loop till event */
/*NOP*/;
} else { /* else small number, convert to hw ticks */
tmo = usec * (TIMER_CLOCK / 1000) / 1000;
/* timeout is no more than 0.1s, and the hw timer will roll over at most once */
tmp = READ_TIMER_HW;
while (((READ_TIMER_HW -tmp) & TIMER_LOAD_VAL) < tmo)/* loop till event */
/*NOP*/;
}
}
ulong get_timer_masked (void)
{
ulong now = READ_TIMER; /* current tick value */
if (now >= gd->arch.lastinc) { /* normal mode (non roll) */
/* move stamp fordward with absoulte diff ticks */
gd->arch.tbl += (now - gd->arch.lastinc);
} else {
/* we have rollover of incrementer */
gd->arch.tbl += ((TIMER_LOAD_VAL / (TIMER_CLOCK / CONFIG_SYS_HZ))
- gd->arch.lastinc) + now;
}
gd->arch.lastinc = now;
return gd->arch.tbl;
}
/*
* 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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