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/*
* (C) Copyright 2009
* 2N Telekomunikace, <www.2n.cz>
*
* (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
* 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 <arm925t.h>
#include <configs/omap1510.h>
#include <asm/io.h>
#define TIMER_LOAD_VAL 0xffffffff
#define TIMER_CLOCK (CONFIG_SYS_CLK_FREQ / (2 << CONFIG_SYS_PTV))
static uint32_t timestamp;
static uint32_t lastdec;
/* nothing really to do with interrupts, just starts up a counter. */
int timer_init (void)
{
/* Start the decrementer ticking down from 0xffffffff */
__raw_writel(TIMER_LOAD_VAL, CONFIG_SYS_TIMERBASE + LOAD_TIM);
__raw_writel(MPUTIM_ST | MPUTIM_AR | MPUTIM_CLOCK_ENABLE |
(CONFIG_SYS_PTV << MPUTIM_PTV_BIT),
CONFIG_SYS_TIMERBASE + CNTL_TIMER);
/* init the timestamp and lastdec value */
lastdec = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM) /
(TIMER_CLOCK / CONFIG_SYS_HZ);
timestamp = 0; /* start "advancing" time stamp from 0 */
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)
{
int32_t tmo = usec * (TIMER_CLOCK / 1000) / 1000;
uint32_t now, last = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM);
while (tmo > 0) {
now = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM);
if (last < now) /* count down timer underflow */
tmo -= TIMER_LOAD_VAL - now + last;
else
tmo -= last - now;
last = now;
}
}
ulong get_timer_masked (void)
{
uint32_t now = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM) /
(TIMER_CLOCK / CONFIG_SYS_HZ);
if (lastdec < now) /* count down timer underflow */
timestamp += TIMER_LOAD_VAL / (TIMER_CLOCK / CONFIG_SYS_HZ) -
now + lastdec;
else
timestamp += lastdec - now;
lastdec = now;
return timestamp;
}
/*
* 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)
{
return CONFIG_SYS_HZ;
}
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