u-boot/arch/sh/lib/time.c
Nobuhiro Iwamatsu 78df8c68cd sh: timer: Remove unnecessary variable 'ticks'
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Reported-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
2012-03-08 10:26:38 +09:00

140 lines
2.8 KiB
C

/*
* (C) Copyright 2009
* Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
*
* (C) Copyright 2007-2010
* 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/clk.h>
#include <asm/io.h>
#define TMU_MAX_COUNTER (~0UL)
static ulong timer_freq;
static unsigned long last_tcnt;
static unsigned long long overflow_ticks;
static inline unsigned long long tick_to_time(unsigned long long tick)
{
tick *= CONFIG_SYS_HZ;
do_div(tick, timer_freq);
return tick;
}
static inline unsigned long long usec_to_tick(unsigned long long usec)
{
usec *= timer_freq;
do_div(usec, 1000000);
return usec;
}
static void tmu_timer_start (unsigned int timer)
{
if (timer > 2)
return;
writeb(readb(TSTR) | (1 << timer), TSTR);
}
static void tmu_timer_stop (unsigned int timer)
{
if (timer > 2)
return;
writeb(readb(TSTR) & ~(1 << timer), TSTR);
}
int timer_init (void)
{
/* Divide clock by CONFIG_SYS_TMU_CLK_DIV */
u16 bit = 0;
switch (CONFIG_SYS_TMU_CLK_DIV) {
case 1024:
bit = 4;
break;
case 256:
bit = 3;
break;
case 64:
bit = 2;
break;
case 16:
bit = 1;
break;
case 4:
default:
break;
}
writew(readw(TCR0) | bit, TCR0);
/* Calc clock rate */
timer_freq = get_tmu0_clk_rate() >> ((bit + 1) * 2);
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(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;
}
unsigned long get_tbclk (void)
{
return timer_freq;
}