1 /* 2 * Based on arch/arm/kernel/time.c 3 * 4 * Copyright (C) 1991, 1992, 1995 Linus Torvalds 5 * Modifications for ARM (C) 1994-2001 Russell King 6 * Copyright (C) 2012 ARM Ltd. 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program. If not, see <http://www.gnu.org/licenses/>. 19 */ 20 21 #include <linux/clockchips.h> 22 #include <linux/export.h> 23 #include <linux/kernel.h> 24 #include <linux/interrupt.h> 25 #include <linux/time.h> 26 #include <linux/init.h> 27 #include <linux/sched.h> 28 #include <linux/smp.h> 29 #include <linux/timex.h> 30 #include <linux/errno.h> 31 #include <linux/profile.h> 32 #include <linux/syscore_ops.h> 33 #include <linux/timer.h> 34 #include <linux/irq.h> 35 #include <linux/delay.h> 36 #include <linux/clocksource.h> 37 #include <linux/clk-provider.h> 38 39 #include <clocksource/arm_arch_timer.h> 40 41 #include <asm/thread_info.h> 42 #include <asm/stacktrace.h> 43 44 #ifdef CONFIG_SMP 45 unsigned long profile_pc(struct pt_regs *regs) 46 { 47 struct stackframe frame; 48 49 if (!in_lock_functions(regs->pc)) 50 return regs->pc; 51 52 frame.fp = regs->regs[29]; 53 frame.sp = regs->sp; 54 frame.pc = regs->pc; 55 do { 56 int ret = unwind_frame(&frame); 57 if (ret < 0) 58 return 0; 59 } while (in_lock_functions(frame.pc)); 60 61 return frame.pc; 62 } 63 EXPORT_SYMBOL(profile_pc); 64 #endif 65 66 void __init time_init(void) 67 { 68 u32 arch_timer_rate; 69 70 of_clk_init(NULL); 71 clocksource_of_init(); 72 73 tick_setup_hrtimer_broadcast(); 74 75 arch_timer_rate = arch_timer_get_rate(); 76 if (!arch_timer_rate) 77 panic("Unable to initialise architected timer.\n"); 78 79 /* Calibrate the delay loop directly */ 80 lpj_fine = arch_timer_rate / HZ; 81 } 82