LXR linux/drivers/clocksource/timer-versatile.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *
   4 * Copyright (C) 2014 ARM Limited
   5 */
   6
   7#include <linux/clocksource.h>
   8#include <linux/io.h>
   9#include <linux/of.h>
  10#include <linux/of_address.h>
  11#include <linux/sched_clock.h>
  12
  13#define SYS_24MHZ 0x05c
  14
  15static void __iomem *versatile_sys_24mhz;
  16
  17static u64 notrace versatile_sys_24mhz_read(void)
  18{
  19        return readl(versatile_sys_24mhz);
  20}
  21
  22static int __init versatile_sched_clock_init(struct device_node *node)
  23{
  24        void __iomem *base = of_iomap(node, 0);
  25
  26        of_node_clear_flag(node, OF_POPULATED);
  27
  28        if (!base)
  29                return -ENXIO;
  30
  31        versatile_sys_24mhz = base + SYS_24MHZ;
  32
  33        sched_clock_register(versatile_sys_24mhz_read, 32, 24000000);
  34
  35        return 0;
  36}
  37TIMER_OF_DECLARE(vexpress, "arm,vexpress-sysreg",
  38                       versatile_sched_clock_init);
  39TIMER_OF_DECLARE(versatile, "arm,versatile-sysreg",
  40                       versatile_sched_clock_init);
  41