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 #include <linux/acpi.h> 39 40 #include <clocksource/arm_arch_timer.h> 41 42 #include <asm/thread_info.h> 43 #include <asm/stacktrace.h> 44 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.pc = regs->pc; 54 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 55 frame.graph = 0; 56 #endif 57 do { 58 int ret = unwind_frame(NULL, &frame); 59 if (ret < 0) 60 return 0; 61 } while (in_lock_functions(frame.pc)); 62 63 return frame.pc; 64 } 65 EXPORT_SYMBOL(profile_pc); 66 67 void __init time_init(void) 68 { 69 u32 arch_timer_rate; 70 71 of_clk_init(NULL); 72 timer_probe(); 73 74 tick_setup_hrtimer_broadcast(); 75 76 arch_timer_rate = arch_timer_get_rate(); 77 if (!arch_timer_rate) 78 panic("Unable to initialise architected timer.\n"); 79 80 /* Calibrate the delay loop directly */ 81 lpj_fine = arch_timer_rate / HZ; 82 } 83