/*
   * 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;
  }
  TIMER_OF_DECLARE(vexpress, "arm,vexpress-sysreg",
  		       versatile_sched_clock_init);
  TIMER_OF_DECLARE(versatile, "arm,versatile-sysreg",
  		       versatile_sched_clock_init);