u-boot/arch/arm/cpu/ixp/timer.c

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/*
* (C) Copyright 2010
* Michael Schwingen, michael@schwingen.org
*
* (C) Copyright 2006
* Stefan Roese, DENX Software Engineering, sr@denx.de.
*
* (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>
*
* 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/arch/ixp425.h>
#include <asm/io.h>
#include <div64.h>
DECLARE_GLOBAL_DATA_PTR;
/*
* The IXP42x time-stamp timer runs at 2*OSC_IN (66.666MHz when using a
* 33.333MHz crystal).
*/
static inline unsigned long long tick_to_time(unsigned long long tick)
{
tick *= CONFIG_SYS_HZ;
do_div(tick, CONFIG_IXP425_TIMER_CLK);
return tick;
}
static inline unsigned long long time_to_tick(unsigned long long time)
{
time *= CONFIG_IXP425_TIMER_CLK;
do_div(time, CONFIG_SYS_HZ);
return time;
}
static inline unsigned long long us_to_tick(unsigned long long us)
{
us = us * CONFIG_IXP425_TIMER_CLK + 999999;
do_div(us, 1000000);
return us;
}
unsigned long long get_ticks(void)
{
ulong now = readl(IXP425_OSTS_B);
if (readl(IXP425_OSST) & IXP425_OSST_TIMER_TS_PEND) {
/* rollover of timestamp timer register */
gd->timestamp += (0xFFFFFFFF - gd->lastinc) + now + 1;
writel(IXP425_OSST_TIMER_TS_PEND, IXP425_OSST);
} else {
/* move stamp forward with absolut diff ticks */
gd->timestamp += (now - gd->lastinc);
}
gd->lastinc = now;
return gd->timestamp;
}
void reset_timer_masked(void)
{
/* capture current timestamp counter */
gd->lastinc = readl(IXP425_OSTS_B);
/* start "advancing" time stamp from 0 */
gd->timestamp = 0;
}
ulong get_timer_masked(void)
{
return tick_to_time(get_ticks());
}
ulong get_timer(ulong base)
{
return get_timer_masked() - base;
}
/* delay x useconds AND preserve advance timestamp value */
void __udelay(unsigned long usec)
{
unsigned long long tmp;
tmp = get_ticks() + us_to_tick(usec);
while (get_ticks() < tmp)
;
}
int timer_init(void)
{
writel(IXP425_OSST_TIMER_TS_PEND, IXP425_OSST);
return 0;
}