xref: /openbmc/linux/arch/riscv/kernel/time.c (revision de3a9980)
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/clocksource.h>
9 #include <linux/delay.h>
10 #include <asm/sbi.h>
11 #include <asm/processor.h>
12 
13 unsigned long riscv_timebase;
14 EXPORT_SYMBOL_GPL(riscv_timebase);
15 
16 void __init time_init(void)
17 {
18 	struct device_node *cpu;
19 	u32 prop;
20 
21 	cpu = of_find_node_by_path("/cpus");
22 	if (!cpu || of_property_read_u32(cpu, "timebase-frequency", &prop))
23 		panic(KERN_WARNING "RISC-V system with no 'timebase-frequency' in DTS\n");
24 	of_node_put(cpu);
25 	riscv_timebase = prop;
26 
27 	lpj_fine = riscv_timebase / HZ;
28 
29 	of_clk_init(NULL);
30 	timer_probe();
31 }
32 
33 void clocksource_arch_init(struct clocksource *cs)
34 {
35 #ifdef CONFIG_GENERIC_GETTIMEOFDAY
36 	cs->vdso_clock_mode = VDSO_CLOCKMODE_ARCHTIMER;
37 #else
38 	cs->vdso_clock_mode = VDSO_CLOCKMODE_NONE;
39 #endif
40 }
41