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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2012-2015 Masahiro Yamada <yamada.masahiro@socionext.com>
*/
#include <config.h>
#include <init.h>
#include <linux/io.h>
#include "arm-mpcore.h"
#define PERIPHCLK (50 * 1000 * 1000) /* 50 MHz */
#define PRESCALER ((PERIPHCLK) / (CFG_SYS_TIMER_RATE) - 1)
static void *get_global_timer_base(void)
{
void *val;
asm("mrc p15, 4, %0, c15, c0, 0" : "=r" (val) : : "memory");
return val + GLOBAL_TIMER_OFFSET;
}
unsigned long timer_read_counter(void)
{
/*
* ARM 64bit Global Timer is too much for our purpose.
* We use only lower 32 bit of the timer counter.
*/
return readl(get_global_timer_base() + GTIMER_CNT_L);
}
int timer_init(void)
{
/* enable timer */
writel(PRESCALER << 8 | 1, get_global_timer_base() + GTIMER_CTRL);
return 0;
}
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