u-boot/arch/arm/cpu/armv7/omap-common/timer.c
Wolfgang Denk 1a4596601f Add GPL-2.0+ SPDX-License-Identifier to source files
Signed-off-by: Wolfgang Denk <wd@denx.de>
[trini: Fixup common/cmd_io.c]
Signed-off-by: Tom Rini <trini@ti.com>
2013-07-24 09:44:38 -04:00

109 lines
2.5 KiB
C

/*
* (C) Copyright 2008
* Texas Instruments
*
* Richard Woodruff <r-woodruff2@ti.com>
* Syed Moahmmed Khasim <khasim@ti.com>
*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Marius Groeger <mgroeger@sysgo.de>
* Alex Zuepke <azu@sysgo.de>
*
* (C) Copyright 2002
* Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/io.h>
#include <asm/arch/cpu.h>
#include <asm/arch/clock.h>
DECLARE_GLOBAL_DATA_PTR;
static struct gptimer *timer_base = (struct gptimer *)CONFIG_SYS_TIMERBASE;
/*
* Nothing really to do with interrupts, just starts up a counter.
*/
#define TIMER_CLOCK (V_SCLK / (2 << CONFIG_SYS_PTV))
#define TIMER_OVERFLOW_VAL 0xffffffff
#define TIMER_LOAD_VAL 0
int timer_init(void)
{
/* start the counter ticking up, reload value on overflow */
writel(TIMER_LOAD_VAL, &timer_base->tldr);
/* enable timer */
writel((CONFIG_SYS_PTV << 2) | TCLR_PRE | TCLR_AR | TCLR_ST,
&timer_base->tclr);
/* reset time, capture current incrementer value time */
gd->arch.lastinc = readl(&timer_base->tcrr) /
(TIMER_CLOCK / CONFIG_SYS_HZ);
gd->arch.tbl = 0; /* start "advancing" time stamp from 0 */
return 0;
}
/*
* timer without interrupts
*/
ulong get_timer(ulong base)
{
return get_timer_masked() - base;
}
/* delay x useconds */
void __udelay(unsigned long usec)
{
long tmo = usec * (TIMER_CLOCK / 1000) / 1000;
unsigned long now, last = readl(&timer_base->tcrr);
while (tmo > 0) {
now = readl(&timer_base->tcrr);
if (last > now) /* count up timer overflow */
tmo -= TIMER_OVERFLOW_VAL - last + now + 1;
else
tmo -= now - last;
last = now;
}
}
ulong get_timer_masked(void)
{
/* current tick value */
ulong now = readl(&timer_base->tcrr) / (TIMER_CLOCK / CONFIG_SYS_HZ);
if (now >= gd->arch.lastinc) { /* normal mode (non roll) */
/* move stamp fordward with absoulte diff ticks */
gd->arch.tbl += (now - gd->arch.lastinc);
} else { /* we have rollover of incrementer */
gd->arch.tbl += ((TIMER_LOAD_VAL / (TIMER_CLOCK /
CONFIG_SYS_HZ)) - gd->arch.lastinc) + now;
}
gd->arch.lastinc = now;
return gd->arch.tbl;
}
/*
* This function is derived from PowerPC code (read timebase as long long).
* On ARM it just returns the timer value.
*/
unsigned long long get_ticks(void)
{
return get_timer(0);
}
/*
* This function is derived from PowerPC code (timebase clock frequency).
* On ARM it returns the number of timer ticks per second.
*/
ulong get_tbclk(void)
{
return CONFIG_SYS_HZ;
}