arch/arm/kernel/arch_timer.c

   1 /*
   2  *  linux/arch/arm/kernel/arch_timer.c
   3  *
   4  *  Copyright (C) 2011 ARM Ltd.
   5  *  All Rights Reserved
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11 #include <linux/init.h>
  12 #include <linux/types.h>
  13 #include <linux/errno.h>
  14
  15 #include <asm/delay.h>
  16
  17 #include <clocksource/arm_arch_timer.h>
  18
  19 static unsigned long arch_timer_read_counter_long(void)
  20 {
  21         return arch_timer_read_counter();
  22 }
  23
  24 static struct delay_timer arch_delay_timer;
  25
  26 static void __init arch_timer_delay_timer_register(void)
  27 {
  28         /* Use the architected timer for the delay loop. */
  29         arch_delay_timer.read_current_timer = arch_timer_read_counter_long;
  30         arch_delay_timer.freq = arch_timer_get_rate();
  31         register_current_timer_delay(&arch_delay_timer);
  32 }
  33
  34 int __init arch_timer_arch_init(void)
  35 {
  36         u32 arch_timer_rate = arch_timer_get_rate();
  37
  38         if (arch_timer_rate == 0)
  39                 return -ENXIO;
  40
  41         arch_timer_delay_timer_register();
  42
  43         return 0;
  44 }