u-boot/arch/arm/cpu/armv7/uniphier/timer.c
Masahiro Yamada 5894ca007d ARM: UniPhier: add UniPhier SoC support code
These are used by Panasonic UniPhier SoC family.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-10-05 14:10:09 +09:00

39 lines
838 B
C

/*
* Copyright (C) 2012-2014 Panasonic Corporation
* Author: Masahiro Yamada <yamada.m@jp.panasonic.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/io.h>
#include <asm/arch/arm-mpcore.h>
#define PERIPHCLK (50 * 1000 * 1000) /* 50 MHz */
#define PRESCALER ((PERIPHCLK) / (CONFIG_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;
}