xref: /linux/arch/riscv/kernel/time.c (revision 0e685c3e7158d35626d6d76b9f859eae806d87fa)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2012 Regents of the University of California
4  * Copyright (C) 2017 SiFive
5  */
6 
7 #include <linux/of_clk.h>
8 #include <linux/clockchips.h>
9 #include <linux/clocksource.h>
10 #include <linux/delay.h>
11 #include <asm/sbi.h>
12 #include <asm/processor.h>
13 #include <asm/timex.h>
14 
15 unsigned long riscv_timebase __ro_after_init;
16 EXPORT_SYMBOL_GPL(riscv_timebase);
17 
18 void __init time_init(void)
19 {
20 	struct device_node *cpu;
21 	u32 prop;
22 
23 	cpu = of_find_node_by_path("/cpus");
24 	if (!cpu || of_property_read_u32(cpu, "timebase-frequency", &prop))
25 		panic(KERN_WARNING "RISC-V system with no 'timebase-frequency' in DTS\n");
26 	of_node_put(cpu);
27 	riscv_timebase = prop;
28 
29 	lpj_fine = riscv_timebase / HZ;
30 
31 	of_clk_init(NULL);
32 	timer_probe();
33 
34 	tick_setup_hrtimer_broadcast();
35 }
36