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