u-boot/arch/sh/lib/time.c

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/*
* (C) Copyright 2009
* Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
*
* (C) Copyright 2007-2012
* Nobobuhiro Iwamatsu <iwamatsu@nigauri.org>
*
* (C) Copyright 2003
* Wolfgang Denk, DENX Software Engineering, wd@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 <div64.h>
#include <asm/processor.h>
#include <asm/io.h>
#include <sh_tmu.h>
static struct tmu_regs *tmu = (struct tmu_regs *)TMU_BASE;
static u16 bit;
static unsigned long last_tcnt;
static unsigned long long overflow_ticks;
unsigned long get_tbclk(void)
{
return get_tmu0_clk_rate() >> ((bit + 1) * 2);
}
static inline unsigned long long tick_to_time(unsigned long long tick)
{
tick *= CONFIG_SYS_HZ;
do_div(tick, get_tbclk());
return tick;
}
static inline unsigned long long usec_to_tick(unsigned long long usec)
{
usec *= get_tbclk();
do_div(usec, 1000000);
return usec;
}
static void tmu_timer_start(unsigned int timer)
{
if (timer > 2)
return;
writeb(readb(&tmu->tstr) | (1 << timer), &tmu->tstr);
}
static void tmu_timer_stop(unsigned int timer)
{
if (timer > 2)
return;
writeb(readb(&tmu->tstr) & ~(1 << timer), &tmu->tstr);
}
int timer_init(void)
{
bit = (ffs(CONFIG_SYS_TMU_CLK_DIV) >> 1) - 1;
writew(readw(&tmu->tcr0) | bit, &tmu->tcr0);
tmu_timer_stop(0);
tmu_timer_start(0);
last_tcnt = 0;
overflow_ticks = 0;
return 0;
}
unsigned long long get_ticks(void)
{
unsigned long tcnt = 0 - readl(&tmu->tcnt0);
if (last_tcnt > tcnt) /* overflow */
overflow_ticks++;
last_tcnt = tcnt;
return (overflow_ticks << 32) | tcnt;
}
void __udelay(unsigned long usec)
{
unsigned long long tmp;
ulong tmo;
tmo = usec_to_tick(usec);
tmp = get_ticks() + tmo; /* get current timestamp */
while (get_ticks() < tmp) /* loop till event */
/*NOP*/;
}
unsigned long get_timer(unsigned long base)
{
/* return msec */
return tick_to_time(get_ticks()) - base;
}
void set_timer(unsigned long t)
{
writel((0 - t), &tmu->tcnt0);
}
void reset_timer(void)
{
tmu_timer_stop(0);
set_timer(0);
tmu_timer_start(0);
}