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/*
* (C) Copyright 2007
* Sascha Hauer, Pengutronix
*
* 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/arch/mx31-regs.h>
#define TIMER_BASE 0x53f90000 /* General purpose timer 1 */
/* General purpose timers registers */
#define GPTCR __REG(TIMER_BASE) /* Control register */
#define GPTPR __REG(TIMER_BASE + 0x4) /* Prescaler register */
#define GPTSR __REG(TIMER_BASE + 0x8) /* Status register */
#define GPTCNT __REG(TIMER_BASE + 0x24) /* Counter register */
/* General purpose timers bitfields */
#define GPTCR_SWR (1 << 15) /* Software reset */
#define GPTCR_FRR (1 << 9) /* Freerun / restart */
#define GPTCR_CLKSOURCE_32 (4 << 6) /* Clock source */
#define GPTCR_TEN 1 /* Timer enable */
/* "time" is measured in 1 / CONFIG_SYS_HZ seconds, "tick" is internal timer period */
#ifdef CONFIG_MX31_TIMER_HIGH_PRECISION
/* ~0.4% error - measured with stop-watch on 100s boot-delay */
#define TICK_TO_TIME(t) ((t) * CONFIG_SYS_HZ / CONFIG_MX31_CLK32)
#define TIME_TO_TICK(t) ((unsigned long long)(t) * CONFIG_MX31_CLK32 / CONFIG_SYS_HZ)
#define US_TO_TICK(t) (((unsigned long long)(t) * CONFIG_MX31_CLK32 + \
999999) / 1000000)
#else
/* ~2% error */
#define TICK_PER_TIME ((CONFIG_MX31_CLK32 + CONFIG_SYS_HZ / 2) / CONFIG_SYS_HZ)
#define US_PER_TICK (1000000 / CONFIG_MX31_CLK32)
#define TICK_TO_TIME(t) ((t) / TICK_PER_TIME)
#define TIME_TO_TICK(t) ((unsigned long long)(t) * TICK_PER_TIME)
#define US_TO_TICK(t) (((t) + US_PER_TICK - 1) / US_PER_TICK)
#endif
static ulong timestamp;
static ulong lastinc;
/* nothing really to do with interrupts, just starts up a counter. */
/* The 32768Hz 32-bit timer overruns in 131072 seconds */
int interrupt_init (void)
{
int i;
/* setup GP Timer 1 */
GPTCR = GPTCR_SWR;
for (i = 0; i < 100; i++)
GPTCR = 0; /* We have no udelay by now */
GPTPR = 0; /* 32Khz */
/* Freerun Mode, PERCLK1 input */
GPTCR |= GPTCR_CLKSOURCE_32 | GPTCR_TEN;
return 0;
}
void reset_timer_masked (void)
{
/* reset time */
lastinc = GPTCNT; /* capture current incrementer value time */
timestamp = 0; /* start "advancing" time stamp from 0 */
}
void reset_timer(void)
{
reset_timer_masked();
}
unsigned long long get_ticks (void)
{
ulong now = GPTCNT; /* current tick value */
if (now >= lastinc) /* normal mode (non roll) */
/* move stamp forward with absolut diff ticks */
timestamp += (now - lastinc);
else /* we have rollover of incrementer */
timestamp += (0xFFFFFFFF - lastinc) + now;
lastinc = now;
return timestamp;
}
ulong get_timer_masked (void)
{
/*
* get_ticks() returns a long long (64 bit), it wraps in
* 2^64 / CONFIG_MX31_CLK32 = 2^64 / 2^15 = 2^49 ~ 5 * 10^14 (s) ~
* 5 * 10^9 days... and get_ticks() * CONFIG_SYS_HZ wraps in
* 5 * 10^6 days - long enough.
*/
return TICK_TO_TIME(get_ticks());
}
ulong get_timer (ulong base)
{
return get_timer_masked () - base;
}
void set_timer (ulong t)
{
timestamp = TIME_TO_TICK(t);
}
/* delay x useconds AND perserve advance timstamp value */
void udelay (unsigned long usec)
{
unsigned long long tmp;
ulong tmo;
tmo = US_TO_TICK(usec);
tmp = get_ticks() + tmo; /* get current timestamp */
while (get_ticks() < tmp) /* loop till event */
/*NOP*/;
}
void reset_cpu (ulong addr)
{
__REG16(WDOG_BASE) = 4;
}
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