xref: /openbmc/linux/arch/riscv/kernel/time.c (revision 305c8388)
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/clocksource.h>
8 #include <linux/delay.h>
9 #include <asm/sbi.h>
10 #include <asm/processor.h>
11 
12 unsigned long riscv_timebase;
13 EXPORT_SYMBOL_GPL(riscv_timebase);
14 
15 void __init time_init(void)
16 {
17 	struct device_node *cpu;
18 	u32 prop;
19 
20 	cpu = of_find_node_by_path("/cpus");
21 	if (!cpu || of_property_read_u32(cpu, "timebase-frequency", &prop))
22 		panic(KERN_WARNING "RISC-V system with no 'timebase-frequency' in DTS\n");
23 	of_node_put(cpu);
24 	riscv_timebase = prop;
25 
26 	lpj_fine = riscv_timebase / HZ;
27 	timer_probe();
28 }
29 
30 void clocksource_arch_init(struct clocksource *cs)
31 {
32 #ifdef CONFIG_GENERIC_GETTIMEOFDAY
33 	cs->vdso_clock_mode = VDSO_CLOCKMODE_ARCHTIMER;
34 #else
35 	cs->vdso_clock_mode = VDSO_CLOCKMODE_NONE;
36 #endif
37 }
38