linux/drivers/clocksource/versatile.c

45 lines
1.2 KiB
C

/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* Copyright (C) 2014 ARM Limited
*/
#include <linux/clocksource.h>
#include <linux/io.h>
#include <linux/of_address.h>
#include <linux/sched_clock.h>
#define SYS_24MHZ 0x05c
static void __iomem *versatile_sys_24mhz;
static u64 notrace versatile_sys_24mhz_read(void)
{
return readl(versatile_sys_24mhz);
}
static int __init versatile_sched_clock_init(struct device_node *node)
{
void __iomem *base = of_iomap(node, 0);
if (!base)
return -ENXIO;
versatile_sys_24mhz = base + SYS_24MHZ;
sched_clock_register(versatile_sys_24mhz_read, 32, 24000000);
return 0;
}
CLOCKSOURCE_OF_DECLARE(vexpress, "arm,vexpress-sysreg",
versatile_sched_clock_init);
CLOCKSOURCE_OF_DECLARE(versatile, "arm,versatile-sysreg",
versatile_sched_clock_init);