1 | // SPDX-License-Identifier: GPL-2.0-only |
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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(path: "/cpus"); |
29 | if (!cpu || of_property_read_u32(np: cpu, propname: "timebase-frequency", out_value: &prop)) |
30 | panic(fmt: "RISC-V system with no 'timebase-frequency' in DTS\n"); |
31 | |
32 | of_node_put(node: cpu); |
33 | riscv_timebase = prop; |
34 | of_clk_init(NULL); |
35 | } else { |
36 | status = acpi_get_table(ACPI_SIG_RHCT, instance: 0, out_table: (struct acpi_table_header **)&rhct); |
37 | if (ACPI_FAILURE(status)) |
38 | panic(fmt: "RISC-V ACPI system with no RHCT table\n"); |
39 | |
40 | riscv_timebase = rhct->time_base_freq; |
41 | acpi_put_table(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 |