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/acpi.h>
8 #include <linux/of_clk.h>
9 #include <linux/clockchips.h>
10 #include <linux/clocksource.h>
11 #include <linux/delay.h>
12 #include <asm/sbi.h>
13 #include <asm/processor.h>
14 #include <asm/timex.h>
15 #include <asm/paravirt.h>
16
17 unsigned long riscv_timebase __ro_after_init;
18 EXPORT_SYMBOL_GPL(riscv_timebase);
19
20 void __init time_init(void)
21 {
22 struct device_node *cpu;
23 struct acpi_table_rhct *rhct;
24 acpi_status status;
25 u32 prop;
26
27 if (acpi_disabled) {
28 cpu = of_find_node_by_path("/cpus");
29 if (!cpu || of_property_read_u32(cpu, "timebase-frequency", &prop))
30 panic("RISC-V system with no 'timebase-frequency' in DTS\n");
31
32 of_node_put(cpu);
33 riscv_timebase = prop;
34 of_clk_init(NULL);
35 } else {
36 status = acpi_get_table(ACPI_SIG_RHCT, 0, (struct acpi_table_header **)&rhct);
37 if (ACPI_FAILURE(status))
38 panic("RISC-V ACPI system with no RHCT table\n");
39
40 riscv_timebase = rhct->time_base_freq;
41 acpi_put_table((struct acpi_table_header *)rhct);
42 }
43
44 lpj_fine = riscv_timebase / HZ;
45
46 timer_probe();
47
48 tick_setup_hrtimer_broadcast();
49
50 pv_time_init();
51 }
52
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