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
17unsigned long riscv_timebase __ro_after_init;
18EXPORT_SYMBOL_GPL(riscv_timebase);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
19
20void __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}

 
 1/*
 2 * Copyright (C) 2012 Regents of the University of California
 3 * Copyright (C) 2017 SiFive
 4 *
 5 *   This program is free software; you can redistribute it and/or
 6 *   modify it under the terms of the GNU General Public License
 7 *   as published by the Free Software Foundation, version 2.
 8 *
 9 *   This program is distributed in the hope that it will be useful,
10 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
11 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 *   GNU General Public License for more details.
13 */
14
 
 
 
15#include <linux/clocksource.h>
16#include <linux/clockchips.h>
17#include <linux/delay.h>
18
19#ifdef CONFIG_RISCV_TIMER
20#include <linux/timer_riscv.h>
21#endif
22
23#include <asm/sbi.h>
 
 
 
24
25unsigned long riscv_timebase;
26
27DECLARE_PER_CPU(struct clock_event_device, riscv_clock_event);
28
29void riscv_timer_interrupt(void)
30{
31#ifdef CONFIG_RISCV_TIMER
32	/*
33	 * FIXME: This needs to be cleaned up along with the rest of the IRQ
34	 * handling cleanup.  See irq.c for more details.
35	 */
36	struct clock_event_device *evdev = this_cpu_ptr(&riscv_clock_event);
37
38	evdev->event_handler(evdev);
39#endif
40}
41
42void __init init_clockevent(void)
43{
44	timer_probe();
45	csr_set(sie, SIE_STIE);
46}
47
48void __init time_init(void)
49{
50	struct device_node *cpu;
 
 
51	u32 prop;
52
53	cpu = of_find_node_by_path("/cpus");
54	if (!cpu || of_property_read_u32(cpu, "timebase-frequency", &prop))
55		panic(KERN_WARNING "RISC-V system with no 'timebase-frequency' in DTS\n");
56	riscv_timebase = prop;
 
 
 
 
 
 
 
 
 
 
 
 
57
58	lpj_fine = riscv_timebase / HZ;
59
60	init_clockevent();
 
 
 
 
61}