1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * ip30-timer.c: Clocksource/clockevent support for the
4 * HEART chip in SGI Octane (IP30) systems.
5 *
6 * Copyright (C) 2004-2007 Stanislaw Skowronek <skylark@unaligned.org>
7 * Copyright (C) 2009 Johannes Dickgreber <tanzy@gmx.de>
8 * Copyright (C) 2011 Joshua Kinard <kumba@gentoo.org>
9 */
10
11 #include <linux/clocksource.h>
12 #include <linux/cpumask.h>
13 #include <linux/init.h>
14 #include <linux/kernel.h>
15 #include <linux/percpu.h>
16 #include <linux/sched_clock.h>
17
18 #include <asm/time.h>
19 #include <asm/cevt-r4k.h>
20 #include <asm/sgi/heart.h>
21
22 static u64 ip30_heart_counter_read(struct clocksource *cs)
23 {
24 return heart_read(&heart_regs->count);
25 }
26
27 struct clocksource ip30_heart_clocksource = {
28 .name = "HEART",
29 .rating = 400,
30 .read = ip30_heart_counter_read,
31 .mask = CLOCKSOURCE_MASK(52),
32 .flags = (CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_VALID_FOR_HRES),
33 };
34
35 static u64 notrace ip30_heart_read_sched_clock(void)
36 {
37 return heart_read(&heart_regs->count);
38 }
39
40 static void __init ip30_heart_clocksource_init(void)
41 {
42 struct clocksource *cs = &ip30_heart_clocksource;
43
44 clocksource_register_hz(cs, HEART_CYCLES_PER_SEC);
45
46 sched_clock_register(ip30_heart_read_sched_clock, 52,
47 HEART_CYCLES_PER_SEC);
48 }
49
50 void __init plat_time_init(void)
51 {
52 int irq = get_c0_compare_int();
53
54 cp0_timer_irq_installed = 1;
55 c0_compare_irqaction.percpu_dev_id = &mips_clockevent_device;
56 c0_compare_irqaction.flags &= ~IRQF_SHARED;
57 irq_set_handler(irq, handle_percpu_devid_irq);
58 irq_set_percpu_devid(irq);
59 setup_percpu_irq(irq, &c0_compare_irqaction);
60 enable_percpu_irq(irq, IRQ_TYPE_NONE);
61
62 ip30_heart_clocksource_init();
63 }
64
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