Во-первых, в новом убуте (с релокацией) в таймере нельзя использовать глобальные переменные, т.к. инициализация таймера вызывается еще до релокации и не сделать fixup адресов. Соответственно Вы ловите сигнал #8, вероятно, при делении на ноль.
Во-вторых, этот код работы с таймером достаточно древний. Гляньте, как сделано в каком-нить омапе. Надо расширить возвращаемое значение тиков до 64 бит.
З.Ы. могу приложить timer.c от s3c2416, кажется таймеря идентичны.
/*
* © Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Marius Groeger <mgroeger@sysgo.de>
*
* © Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Alex Zuepke <azu@sysgo.de>
*
* © 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>
#ifdef CONFIG_S3C2416
#include <asm/io.h>
#include <asm/arch/s3c24x0_cpu.h>
#include <div64.h>
DECLARE_GLOBAL_DATA_PTR;
#define TIMER_PREDIV_2 0
#define TIMER_PREDIV_4 1
#define TIMER_PREDIV_8 2
#define TIMER_PREDIV_16 3
/*
* Timer is 16-bit
* So we can have good (small) timer resolution OR good (big) overlap time
* PCLK usualy 66 MHz
* PCLK / 2 / 33 = 1 MHz, 1 uS @ tick, overlap after 65 mS
* PCLK / 4 / 165 = 0.1 MHz ,10 uS @ tick, overlap after 650 mS
* PCLK / 16 / 165 = 0.025 MHz, 40 uS @ tick, overlap after 2,5 S
* ...etc
*/
#define TIMER_PRESCALER 165
#define TIMER_PREDIV TIMER_PREDIV_4 //2, 4, 8, 16
static inline unsigned long long tick_to_time(unsigned long long tick)
{
tick *= CONFIG_SYS_HZ;
do_div(tick, gd->timer_rate_hz);
return tick;
}
static inline unsigned long long usec_to_tick(unsigned long long usec)
{
usec *= gd->timer_rate_hz;
do_div(usec, 1000000);
return usec;
}
int timer_init(void)
{
struct s3c24x0_timers *timers = s3c24x0_get_base_timers();
ulong tmr;
/* use PWM Timer 4 because it has no output */
/* prescaler for Timer */
writel(((TIMER_PRESCALER - 1) << 8) | (TIMER_PRESCALER - 1), &timers->TCFG0);
/* PREDIV */
writel((readl(&timers->TCFG1) & ~(0x0F << 16)) | (TIMER_PREDIV << 16), &timers->TCFG1);
/* Reload value */
writel(0xFFFF, &timers->TCNTB4);
/* auto load, manual update of Timer 4 */
tmr = (readl(&timers->TCON) & ~0x0700000) | 0x0600000;
writel(tmr, &timers->TCON);
/* auto load, start Timer 4 */
tmr = (tmr & ~0x0700000) | 0x0500000;
writel(tmr, &timers->TCON);
gd->lastinc = 0;
gd->timer_rate_hz = get_PCLK() / (TIMER_PRESCALER * (1 << (TIMER_PREDIV + 1)));
gd->tbu = gd->tbl = 0;
return (0);
}
/*
* macro to read the count-down 16 bit timer
*/
static inline ulong READ_TIMER16(void)
{
struct s3c24x0_timers *timers = s3c24x0_get_base_timers();
return (0xFFFF - ((readl(&timers->TCNTO4) & 0xFFFF)));
}
static inline ulong READ_TIMER32(void)
{
ulong now = READ_TIMER16();
ulong tbl = gd->tbl;
if (now >= (tbl & 0xFFFF))
tbl = (tbl & 0xFFFF0000) | now;
else
tbl = ((tbl & 0xFFFF0000) | now) + 0x00010000;
return tbl;
}
/*
* Get the current 64 bit timer tick count
*/
unsigned long long get_ticks(void)
{
ulong now = READ_TIMER32();
/* increment tbu if tbl has rolled over */
if (now < gd->tbl)
gd->tbu++;
gd->tbl = now;
return (((unsigned long long)gd->tbu) << 32) | gd->tbl;
}
void __udelay(unsigned long usec)
{
unsigned long long start;
unsigned long long tmo;
start = get_ticks(); /* get current timestamp */
tmo = usec_to_tick(usec); /* convert usecs to ticks */
if (tmo == 0)
tmo = 1;
while ((get_ticks() - start) < tmo)
; /* loop till time has passed */
}
/*
* get_timer(base) can be used to check for timeouts or
* to measure elasped time relative to an event:
*
* ulong start_time = get_timer(0) sets start_time to the current
* time value.
* get_timer(start_time) returns the time elapsed since then.
*
* The time is used in CONFIG_SYS_HZ units!
*/
ulong get_timer(ulong base)
{
return tick_to_time(get_ticks()) - base;
}
ulong get_timer_masked (void)
{
return tick_to_time(get_ticks());
}
/*
* Return the number of timer ticks per second.
*/
ulong get_tbclk(void)
{
return gd->timer_rate_hz;
}
#endif /* CONFIG_S3C2416 */
U-boot, mini2440, nand
Mar 23 2012, 20:06
