1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 *
4 * Copyright (C) 2015 Numascale AS. All rights reserved.
5 */
6
7 #include <linux/clockchips.h>
8
9 #include <asm/irq.h>
10 #include <asm/numachip/numachip.h>
11 #include <asm/numachip/numachip_csr.h>
12
13 static DEFINE_PER_CPU(struct clock_event_device, numachip2_ced);
14
numachip2_timer_read(struct clocksource * cs)15 static cycles_t numachip2_timer_read(struct clocksource *cs)
16 {
17 return numachip2_read64_lcsr(NUMACHIP2_TIMER_NOW);
18 }
19
20 static struct clocksource numachip2_clocksource = {
21 .name = "numachip2",
22 .rating = 295,
23 .read = numachip2_timer_read,
24 .mask = CLOCKSOURCE_MASK(64),
25 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
26 .mult = 1,
27 .shift = 0,
28 };
29
numachip2_set_next_event(unsigned long delta,struct clock_event_device * ced)30 static int numachip2_set_next_event(unsigned long delta, struct clock_event_device *ced)
31 {
32 numachip2_write64_lcsr(NUMACHIP2_TIMER_DEADLINE + numachip2_timer(),
33 delta);
34 return 0;
35 }
36
37 static const struct clock_event_device numachip2_clockevent __initconst = {
38 .name = "numachip2",
39 .rating = 400,
40 .set_next_event = numachip2_set_next_event,
41 .features = CLOCK_EVT_FEAT_ONESHOT,
42 .mult = 1,
43 .shift = 0,
44 .min_delta_ns = 1250,
45 .min_delta_ticks = 1250,
46 .max_delta_ns = LONG_MAX,
47 .max_delta_ticks = LONG_MAX,
48 };
49
numachip_timer_interrupt(void)50 static void numachip_timer_interrupt(void)
51 {
52 struct clock_event_device *ced = this_cpu_ptr(&numachip2_ced);
53
54 ced->event_handler(ced);
55 }
56
numachip_timer_each(struct work_struct * work)57 static __init void numachip_timer_each(struct work_struct *work)
58 {
59 unsigned local_apicid = __this_cpu_read(x86_cpu_to_apicid) & 0xff;
60 struct clock_event_device *ced = this_cpu_ptr(&numachip2_ced);
61
62 /* Setup IPI vector to local core and relative timing mode */
63 numachip2_write64_lcsr(NUMACHIP2_TIMER_INT + numachip2_timer(),
64 (3 << 22) | (X86_PLATFORM_IPI_VECTOR << 14) |
65 (local_apicid << 6));
66
67 *ced = numachip2_clockevent;
68 ced->cpumask = cpumask_of(smp_processor_id());
69 clockevents_register_device(ced);
70 }
71
numachip_timer_init(void)72 static int __init numachip_timer_init(void)
73 {
74 if (numachip_system != 2)
75 return -ENODEV;
76
77 /* Reset timer */
78 numachip2_write64_lcsr(NUMACHIP2_TIMER_RESET, 0);
79 clocksource_register_hz(&numachip2_clocksource, NSEC_PER_SEC);
80
81 /* Setup per-cpu clockevents */
82 x86_platform_ipi_callback = numachip_timer_interrupt;
83 schedule_on_each_cpu(&numachip_timer_each);
84
85 return 0;
86 }
87
88 arch_initcall(numachip_timer_init);
89