u-boot/arch/arm/cpu/armv7/highbank/timer.c
Rob Herring ceb2071c6b ARM: highbank: fix us_to_tick calculation
udelay calls were off due to failing to convert us to ns. Fix this and drop
the unnecessary shifts since NS_PER_TICK is only 7ns.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
2012-03-28 23:31:08 +02:00

128 lines
2.9 KiB
C

/*
* Copyright 2010-2011 Calxeda, Inc.
*
* Based on arm926ejs/mx27/timer.c
*
* 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 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, see <http://www.gnu.org/licenses/>.
*/
#include <common.h>
#include <div64.h>
#include <linux/types.h> /* for size_t */
#include <linux/stddef.h> /* for NULL */
#include <asm/io.h>
#include <asm/arch-armv7/systimer.h>
#undef SYSTIMER_BASE
#define SYSTIMER_BASE 0xFFF34000 /* Timer 0 and 1 base */
#define SYSTIMER_RATE 150000000
static ulong timestamp;
static ulong lastinc;
static struct systimer *systimer_base = (struct systimer *)SYSTIMER_BASE;
/*
* Start the timer
*/
int timer_init(void)
{
/*
* Setup timer0
*/
writel(SYSTIMER_RELOAD, &systimer_base->timer0load);
writel(SYSTIMER_RELOAD, &systimer_base->timer0value);
writel(SYSTIMER_EN | SYSTIMER_32BIT, &systimer_base->timer0control);
reset_timer_masked();
return 0;
}
#define TICK_PER_TIME ((SYSTIMER_RATE + CONFIG_SYS_HZ / 2) / CONFIG_SYS_HZ)
#define NS_PER_TICK (1000000000 / SYSTIMER_RATE)
static inline unsigned long long tick_to_time(unsigned long long tick)
{
do_div(tick, TICK_PER_TIME);
return tick;
}
static inline unsigned long long time_to_tick(unsigned long long time)
{
return time * TICK_PER_TIME;
}
static inline unsigned long long us_to_tick(unsigned long long us)
{
unsigned long long tick = us * 1000;
tick += NS_PER_TICK - 1;
do_div(tick, NS_PER_TICK);
return tick;
}
unsigned long long get_ticks(void)
{
ulong now = ~readl(&systimer_base->timer0value);
if (now >= lastinc) /* normal mode (non roll) */
/* move stamp forward with absolut diff ticks */
timestamp += (now - lastinc);
else /* we have rollover of incrementer */
timestamp += (0xFFFFFFFF - lastinc) + now;
lastinc = now;
return timestamp;
}
/*
* Delay x useconds AND preserve advance timstamp value
* assumes timer is ticking at 1 msec
*/
void __udelay(ulong usec)
{
unsigned long long tmp;
ulong tmo;
tmo = us_to_tick(usec);
tmp = get_ticks() + tmo; /* get current timestamp */
while (get_ticks() < tmp) /* loop till event */
/*NOP*/;
}
ulong get_timer(ulong base)
{
return get_timer_masked() - base;
}
void reset_timer_masked(void)
{
lastinc = ~readl(&systimer_base->timer0value);
timestamp = 0;
}
void reset_timer(void)
{
reset_timer_masked();
}
ulong get_timer_masked(void)
{
return tick_to_time(get_ticks());
}
ulong get_tbclk(void)
{
return CONFIG_SYS_HZ;
}