[people/ms/u-boot.git] / arch / arm / mach-uniphier / timer.c

/*
 * Copyright (C) 2012-2015 Masahiro Yamada <yamada.masahiro@socionext.com>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <linux/io.h>

#include "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;
}
Commit	Line	Data
5894ca00	1	/*
f6e7f07c	2	* Copyright (C) 2012-2015 Masahiro Yamada <yamada.masahiro@socionext.com>
5894ca00 MY	3	*
	4	* SPDX-License-Identifier: GPL-2.0+
	5	*/
	6
	7	#include <common.h>
f6e7f07c	8	#include <linux/io.h>
107b3fb4 MY	9
107b3fb4 MY	10	#include "arm-mpcore.h"
5894ca00 MY	11
	12	#define PERIPHCLK (50 * 1000 * 1000) /* 50 MHz */
	13	#define PRESCALER ((PERIPHCLK) / (CONFIG_SYS_TIMER_RATE) - 1)
	14
	15	static void *get_global_timer_base(void)
	16	{
	17	void *val;
	18
	19	asm("mrc p15, 4, %0, c15, c0, 0" : "=r" (val) : : "memory");
	20
	21	return val + GLOBAL_TIMER_OFFSET;
	22	}
	23
	24	unsigned long timer_read_counter(void)
	25	{
	26	/*
	27	* ARM 64bit Global Timer is too much for our purpose.
	28	* We use only lower 32 bit of the timer counter.
	29	*/
	30	return readl(get_global_timer_base() + GTIMER_CNT_L);
	31	}
	32
	33	int timer_init(void)
	34	{
	35	/* enable timer */
	36	writel(PRESCALER << 8 \| 1, get_global_timer_base() + GTIMER_CTRL);
	37
	38	return 0;
	39	}