1 /* 2 * Copyright (C) 2012 Regents of the University of California 3 * Copyright (C) 2017 SiFive 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU General Public License 7 * as published by the Free Software Foundation, version 2. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 */ 14 15 #include <linux/clocksource.h> 16 #include <linux/delay.h> 17 #include <asm/sbi.h> 18 19 unsigned long riscv_timebase; 20 21 void __init time_init(void) 22 { 23 struct device_node *cpu; 24 u32 prop; 25 26 cpu = of_find_node_by_path("/cpus"); 27 if (!cpu || of_property_read_u32(cpu, "timebase-frequency", &prop)) 28 panic(KERN_WARNING "RISC-V system with no 'timebase-frequency' in DTS\n"); 29 of_node_put(cpu); 30 riscv_timebase = prop; 31 32 lpj_fine = riscv_timebase / HZ; 33 timer_probe(); 34 } 35