u-boot/arch/arm/cpu/lh7a40x/timer.c

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/*
* (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 <lh7a40x.h>
static ulong timer_load_val = 0;
/* macro to read the 16 bit timer */
static inline ulong READ_TIMER(void)
{
lh7a40x_timers_t* timers = LH7A40X_TIMERS_PTR;
lh7a40x_timer_t* timer = &timers->timer1;
return (timer->value & 0x0000ffff);
}
static ulong timestamp;
static ulong lastdec;
int timer_init (void)
{
lh7a40x_timers_t* timers = LH7A40X_TIMERS_PTR;
lh7a40x_timer_t* timer = &timers->timer1;
/* a periodic timer using the 508kHz source */
timer->control = (TIMER_PER | TIMER_CLK508K);
if (timer_load_val == 0) {
/*
* 10ms period with 508.469kHz clock = 5084
*/
timer_load_val = CONFIG_SYS_HZ/100;
}
/* load value for 10 ms timeout */
lastdec = timer->load = timer_load_val;
/* auto load, start timer */
timer->control = timer->control | TIMER_EN;
timestamp = 0;
return (0);
}
/*
* timer without interrupts
*/
ulong get_timer (ulong base)
{
return (get_timer_masked() - base);
}
void __udelay (unsigned long usec)
{
ulong tmo,tmp;
/* normalize */
if (usec >= 1000) {
tmo = usec / 1000;
tmo *= CONFIG_SYS_HZ;
tmo /= 1000;
}
else {
if (usec > 1) {
tmo = usec * CONFIG_SYS_HZ;
tmo /= (1000*1000);
}
else
tmo = 1;
}
/* check for rollover during this delay */
tmp = get_timer (0);
if ((tmp + tmo) < tmp )
reset_timer_masked(); /* timer would roll over */
else
tmo += tmp;
while (get_timer_masked () < tmo);
}
void reset_timer_masked (void)
{
/* reset time */
lastdec = READ_TIMER();
timestamp = 0;
}
ulong get_timer_masked (void)
{
ulong now = READ_TIMER();
if (lastdec >= now) {
/* normal mode */
timestamp += (lastdec - now);
} else {
/* we have an overflow ... */
timestamp += ((lastdec + timer_load_val) - now);
}
lastdec = now;
return timestamp;
}
void udelay_masked (unsigned long usec)
{
ulong tmo;
ulong endtime;
signed long diff;
/* normalize */
if (usec >= 1000) {
tmo = usec / 1000;
tmo *= CONFIG_SYS_HZ;
tmo /= 1000;
} else {
if (usec > 1) {
tmo = usec * CONFIG_SYS_HZ;
tmo /= (1000*1000);
} else {
tmo = 1;
}
}
endtime = get_timer_masked () + tmo;
do {
ulong now = get_timer_masked ();
diff = endtime - now;
} while (diff >= 0);
}
/*
* 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 = timer_load_val * 100;
return tbclk;
}