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/*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Marius Groeger <mgroeger@sysgo.de>
*
* (C) Copyright 2002
* David Mueller, ELSOFT AG, <d.mueller@elsoft.ch>
*
* (C) Copyright 2003
* Texas Instruments, <www.ti.com>
* Kshitij Gupta <Kshitij@ti.com>
*
* (C) Copyright 2004
* ARM Ltd.
* Philippe Robin, <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>
/* The Integrator/AP timer1 is clocked at 24MHz
* can be divided by 16 or 256
* and is a 16-bit counter
*/
/* U-Boot expects a 32 bit timer running at CONFIG_SYS_HZ*/
static ulong timestamp; /* U-Boot ticks since startup */
static ulong total_count = 0; /* Total timer count */
static ulong lastdec; /* Timer reading at last call */
static ulong div_clock = 256; /* Divisor applied to the timer clock */
static ulong div_timer = 1; /* Divisor to convert timer reading
* change to U-Boot ticks
*/
/* CONFIG_SYS_HZ = CONFIG_SYS_HZ_CLOCK/(div_clock * div_timer) */
#define TIMER_LOAD_VAL 0x0000FFFFL
#define READ_TIMER ((*(volatile ulong *)(CONFIG_SYS_TIMERBASE+4)) & 0x0000FFFFL)
/* all function return values in U-Boot ticks i.e. (1/CONFIG_SYS_HZ) sec
* - unless otherwise stated
*/
/* starts a counter
* - the Integrator/AP timer issues an interrupt
* each time it reaches zero
*/
int timer_init (void)
{
/* Load timer with initial value */
*(volatile ulong *)(CONFIG_SYS_TIMERBASE + 0) = TIMER_LOAD_VAL;
/* Set timer to be
* enabled 1
* free-running 0
* XX 00
* divider 256 10
* XX 00
*/
*(volatile ulong *)(CONFIG_SYS_TIMERBASE + 8) = 0x00000088;
total_count = 0;
/* init the timestamp and lastdec value */
reset_timer_masked();
div_timer = CONFIG_SYS_HZ_CLOCK / CONFIG_SYS_HZ;
div_timer /= div_clock;
return (0);
}
/*
* timer without interrupts
*/
void reset_timer (void)
{
reset_timer_masked ();
}
ulong get_timer (ulong base_ticks)
{
return get_timer_masked () - base_ticks;
}
void set_timer (ulong ticks)
{
timestamp = ticks;
total_count = ticks * div_timer;
reset_timer_masked();
}
/* delay x useconds */
void udelay (unsigned long usec)
{
ulong tmo, tmp;
/* Convert to U-Boot ticks */
tmo = usec * CONFIG_SYS_HZ;
tmo /= (1000000L);
tmp = get_timer_masked(); /* get current timestamp */
tmo += tmp; /* wake up timestamp */
while (get_timer_masked () < tmo) { /* loop till event */
/*NOP*/;
}
}
void reset_timer_masked (void)
{
/* reset time */
lastdec = READ_TIMER; /* capture current decrementer value */
timestamp = 0; /* start "advancing" time stamp from 0 */
}
/* converts the timer reading to U-Boot ticks */
/* the timestamp is the number of ticks since reset */
/* This routine does not detect wraps unless called regularly
ASSUMES a call at least every 16 seconds to detect every reload */
ulong get_timer_masked (void)
{
ulong now = READ_TIMER; /* current count */
if (now > lastdec) {
/* Must have wrapped */
total_count += lastdec + TIMER_LOAD_VAL + 1 - now;
} else {
total_count += lastdec - now;
}
lastdec = now;
timestamp = total_count/div_timer;
return timestamp;
}
/* waits specified delay value and resets timestamp */
void udelay_masked (unsigned long usec)
{
udelay(usec);
}
/*
* 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);
}
/*
* Return the timebase clock frequency
* i.e. how often the timer decrements
*/
ulong get_tbclk (void)
{
return CONFIG_SYS_HZ_CLOCK/div_clock;
}
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