ef917ddb1d
Move arch/arm/cpu/arm926ejs/nomadik/* -> arch/arm/mach-nomadik/* Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com> Cc: Nomadik Linux Team <STN_WMM_nomadik_linux@list.st.com> Cc: Alessandro Rubini <rubini@unipv.it>
72 lines
1.6 KiB
C
72 lines
1.6 KiB
C
/*
|
|
* (C) Copyright 2009 Alessandro Rubini
|
|
*
|
|
* SPDX-License-Identifier: GPL-2.0+
|
|
*/
|
|
|
|
#include <common.h>
|
|
#include <asm/io.h>
|
|
#include <asm/arch/mtu.h>
|
|
|
|
/*
|
|
* The timer is a decrementer, we'll left it free running at 2.4MHz.
|
|
* We have 2.4 ticks per microsecond and an overflow in almost 30min
|
|
*/
|
|
#define TIMER_CLOCK (24 * 100 * 1000)
|
|
#define COUNT_TO_USEC(x) ((x) * 5 / 12) /* overflows at 6min */
|
|
#define USEC_TO_COUNT(x) ((x) * 12 / 5) /* overflows at 6min */
|
|
#define TICKS_PER_HZ (TIMER_CLOCK / CONFIG_SYS_HZ)
|
|
#define TICKS_TO_HZ(x) ((x) / TICKS_PER_HZ)
|
|
|
|
/* macro to read the decrementing 32 bit timer as an increasing count */
|
|
#define READ_TIMER() (0 - readl(CONFIG_SYS_TIMERBASE + MTU_VAL(0)))
|
|
|
|
/* Configure a free-running, auto-wrap counter with no prescaler */
|
|
int timer_init(void)
|
|
{
|
|
ulong val;
|
|
|
|
writel(MTU_CRn_ENA | MTU_CRn_PRESCALE_1 | MTU_CRn_32BITS,
|
|
CONFIG_SYS_TIMERBASE + MTU_CR(0));
|
|
|
|
/* Reset the timer */
|
|
writel(0, CONFIG_SYS_TIMERBASE + MTU_LR(0));
|
|
/*
|
|
* The load-register isn't really immediate: it changes on clock
|
|
* edges, so we must wait for our newly-written value to appear.
|
|
* Since we might miss reading 0, wait for any change in value.
|
|
*/
|
|
val = READ_TIMER();
|
|
while (READ_TIMER() == val)
|
|
;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Return how many HZ passed since "base" */
|
|
ulong get_timer(ulong base)
|
|
{
|
|
return TICKS_TO_HZ(READ_TIMER()) - base;
|
|
}
|
|
|
|
/* Delay x useconds */
|
|
void __udelay(unsigned long usec)
|
|
{
|
|
ulong ini, end;
|
|
|
|
ini = READ_TIMER();
|
|
end = ini + USEC_TO_COUNT(usec);
|
|
while ((signed)(end - READ_TIMER()) > 0)
|
|
;
|
|
}
|
|
|
|
unsigned long long get_ticks(void)
|
|
{
|
|
return get_timer(0);
|
|
}
|
|
|
|
ulong get_tbclk(void)
|
|
{
|
|
return CONFIG_SYS_HZ;
|
|
}
|