u-boot/cpu/sh3/time.c

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/*
* (C) Copyright 2007
* Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
*
* (C) Copyright 2007
* 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 <asm/processor.h>
#include <asm/io.h>
#define TMU_MAX_COUNTER (~0UL)
static void tmu_timer_start(unsigned int timer)
{
if (timer > 2)
return;
outb(inb(TSTR) | (1 << timer), TSTR);
}
static void tmu_timer_stop(unsigned int timer)
{
u8 val = inb(TSTR);
if (timer > 2)
return;
outb(val & ~(1 << timer), TSTR);
}
int timer_init(void)
{
/* Divide clock by 4 */
outw(0, TCR0);
tmu_timer_stop(0);
tmu_timer_start(0);
return 0;
}
/*
In theory we should return a true 64bit value (ie something that doesn't
overflow). However, we don't. Therefore if TMU runs at fastest rate of
6.75 MHz this value will wrap after u-boot has been running for approx
10 minutes.
*/
unsigned long long get_ticks(void)
{
return (0 - inl(TCNT0));
}
unsigned long get_timer(unsigned long base)
{
return ((0 - inl(TCNT0)) - base);
}
void set_timer(unsigned long t)
{
outl(0 - t, TCNT0);
}
void reset_timer(void)
{
tmu_timer_stop(0);
set_timer(0);
tmu_timer_start(0);
}
void udelay(unsigned long usec)
{
unsigned int start = get_timer(0);
unsigned int end = start + (usec * ((CFG_HZ + 500000) / 1000000));
while (get_timer(0) < end)
continue;
}
unsigned long get_tbclk(void)
{
return CFG_HZ;
}