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6#include <linux/clockchips.h>
7#include <linux/init.h>
8#include <linux/interrupt.h>
9#include <linux/jiffies.h>
10#include <linux/threads.h>
11#include <asm/irq.h>
12#include <asm/param.h>
13#include "kern_util.h"
14#include "os.h"
15
16void timer_handler(int sig, struct uml_pt_regs *regs)
17{
18 unsigned long flags;
19
20 local_irq_save(flags);
21 do_IRQ(TIMER_IRQ, regs);
22 local_irq_restore(flags);
23}
24
25static void itimer_set_mode(enum clock_event_mode mode,
26 struct clock_event_device *evt)
27{
28 switch (mode) {
29 case CLOCK_EVT_MODE_PERIODIC:
30 set_interval();
31 break;
32
33 case CLOCK_EVT_MODE_SHUTDOWN:
34 case CLOCK_EVT_MODE_UNUSED:
35 case CLOCK_EVT_MODE_ONESHOT:
36 disable_timer();
37 break;
38
39 case CLOCK_EVT_MODE_RESUME:
40 break;
41 }
42}
43
44static int itimer_next_event(unsigned long delta,
45 struct clock_event_device *evt)
46{
47 return timer_one_shot(delta + 1);
48}
49
50static struct clock_event_device itimer_clockevent = {
51 .name = "itimer",
52 .rating = 250,
53 .cpumask = cpu_all_mask,
54 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
55 .set_mode = itimer_set_mode,
56 .set_next_event = itimer_next_event,
57 .shift = 32,
58 .irq = 0,
59};
60
61static irqreturn_t um_timer(int irq, void *dev)
62{
63 (*itimer_clockevent.event_handler)(&itimer_clockevent);
64
65 return IRQ_HANDLED;
66}
67
68static cycle_t itimer_read(struct clocksource *cs)
69{
70 return os_nsecs() / 1000;
71}
72
73static struct clocksource itimer_clocksource = {
74 .name = "itimer",
75 .rating = 300,
76 .read = itimer_read,
77 .mask = CLOCKSOURCE_MASK(64),
78 .mult = 1000,
79 .shift = 0,
80 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
81};
82
83static void __init setup_itimer(void)
84{
85 int err;
86
87 err = request_irq(TIMER_IRQ, um_timer, IRQF_DISABLED, "timer", NULL);
88 if (err != 0)
89 printk(KERN_ERR "register_timer : request_irq failed - "
90 "errno = %d\n", -err);
91
92 itimer_clockevent.mult = div_sc(HZ, NSEC_PER_SEC, 32);
93 itimer_clockevent.max_delta_ns =
94 clockevent_delta2ns(60 * HZ, &itimer_clockevent);
95 itimer_clockevent.min_delta_ns =
96 clockevent_delta2ns(1, &itimer_clockevent);
97 err = clocksource_register(&itimer_clocksource);
98 if (err) {
99 printk(KERN_ERR "clocksource_register returned %d\n", err);
100 return;
101 }
102 clockevents_register_device(&itimer_clockevent);
103}
104
105void read_persistent_clock(struct timespec *ts)
106{
107 long long nsecs = os_nsecs();
108
109 set_normalized_timespec(ts, nsecs / NSEC_PER_SEC,
110 nsecs % NSEC_PER_SEC);
111}
112
113void __init time_init(void)
114{
115 timer_init();
116 late_time_init = setup_itimer;
117}
118
