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 #include <asm/sched_clock.h> 17 18 #include <clocksource/arm_arch_timer.h> 19 20 static unsigned long arch_timer_read_counter_long(void) 21 { 22 return arch_timer_read_counter(); 23 } 24 25 static u32 arch_timer_read_counter_u32(void) 26 { 27 return arch_timer_read_counter(); 28 } 29 30 static struct delay_timer arch_delay_timer; 31 32 static void __init arch_timer_delay_timer_register(void) 33 { 34 /* Use the architected timer for the delay loop. */ 35 arch_delay_timer.read_current_timer = arch_timer_read_counter_long; 36 arch_delay_timer.freq = arch_timer_get_rate(); 37 register_current_timer_delay(&arch_delay_timer); 38 } 39 40 int __init arch_timer_of_register(void) 41 { 42 int ret; 43 44 ret = arch_timer_init(); 45 if (ret) 46 return ret; 47 48 arch_timer_delay_timer_register(); 49 50 return 0; 51 } 52 53 int __init arch_timer_sched_clock_init(void) 54 { 55 if (arch_timer_get_rate() == 0) 56 return -ENXIO; 57 58 setup_sched_clock(arch_timer_read_counter_u32, 59 32, arch_timer_get_rate()); 60 return 0; 61 } 62