1 /* MN10300 clockevents
2 *
3 * Copyright (C) 2010 Red Hat, Inc. All Rights Reserved.
4 * Written by Mark Salter (msalter@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 */
11 #include <linux/clockchips.h>
12 #include <linux/interrupt.h>
13 #include <linux/percpu.h>
14 #include <linux/smp.h>
15 #include <asm/timex.h>
16 #include "internal.h"
17
18 #ifdef CONFIG_SMP
19 #if (CONFIG_NR_CPUS > 2) && !defined(CONFIG_GEENERIC_CLOCKEVENTS_BROADCAST)
20 #error "This doesn't scale well! Need per-core local timers."
21 #endif
22 #else /* CONFIG_SMP */
23 #define stop_jiffies_counter1()
24 #define reload_jiffies_counter1(x)
25 #define TMJC1IRQ TMJCIRQ
26 #endif
27
28
next_event(unsigned long delta,struct clock_event_device * evt)29 static int next_event(unsigned long delta,
30 struct clock_event_device *evt)
31 {
32 unsigned int cpu = smp_processor_id();
33
34 if (cpu == 0) {
35 stop_jiffies_counter();
36 reload_jiffies_counter(delta - 1);
37 } else {
38 stop_jiffies_counter1();
39 reload_jiffies_counter1(delta - 1);
40 }
41 return 0;
42 }
43
set_clock_mode(enum clock_event_mode mode,struct clock_event_device * evt)44 static void set_clock_mode(enum clock_event_mode mode,
45 struct clock_event_device *evt)
46 {
47 /* Nothing to do ... */
48 }
49
50 static DEFINE_PER_CPU(struct clock_event_device, mn10300_clockevent_device);
51 static DEFINE_PER_CPU(struct irqaction, timer_irq);
52
timer_interrupt(int irq,void * dev_id)53 static irqreturn_t timer_interrupt(int irq, void *dev_id)
54 {
55 struct clock_event_device *cd;
56 unsigned int cpu = smp_processor_id();
57
58 if (cpu == 0)
59 stop_jiffies_counter();
60 else
61 stop_jiffies_counter1();
62
63 cd = &per_cpu(mn10300_clockevent_device, cpu);
64 cd->event_handler(cd);
65
66 return IRQ_HANDLED;
67 }
68
event_handler(struct clock_event_device * dev)69 static void event_handler(struct clock_event_device *dev)
70 {
71 }
72
init_clockevents(void)73 int __init init_clockevents(void)
74 {
75 struct clock_event_device *cd;
76 struct irqaction *iact;
77 unsigned int cpu = smp_processor_id();
78
79 cd = &per_cpu(mn10300_clockevent_device, cpu);
80
81 if (cpu == 0) {
82 stop_jiffies_counter();
83 cd->irq = TMJCIRQ;
84 } else {
85 stop_jiffies_counter1();
86 cd->irq = TMJC1IRQ;
87 }
88
89 cd->name = "Timestamp";
90 cd->features = CLOCK_EVT_FEAT_ONESHOT;
91
92 /* Calculate shift/mult. We want to spawn at least 1 second */
93 clockevents_calc_mult_shift(cd, MN10300_JCCLK, 1);
94
95 /* Calculate the min / max delta */
96 cd->max_delta_ns = clockevent_delta2ns(TMJCBR_MAX, cd);
97 cd->min_delta_ns = clockevent_delta2ns(100, cd);
98
99 cd->rating = 200;
100 cd->cpumask = cpumask_of(smp_processor_id());
101 cd->set_mode = set_clock_mode;
102 cd->event_handler = event_handler;
103 cd->set_next_event = next_event;
104
105 iact = &per_cpu(timer_irq, cpu);
106 iact->flags = IRQF_DISABLED | IRQF_SHARED | IRQF_TIMER;
107 iact->handler = timer_interrupt;
108
109 clockevents_register_device(cd);
110
111 #if defined(CONFIG_SMP) && !defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST)
112 /* setup timer irq affinity so it only runs on this cpu */
113 {
114 struct irq_data *data;
115 data = irq_get_irq_data(cd->irq);
116 cpumask_copy(data->affinity, cpumask_of(cpu));
117 iact->flags |= IRQF_NOBALANCING;
118 }
119 #endif
120
121 if (cpu == 0) {
122 reload_jiffies_counter(MN10300_JC_PER_HZ - 1);
123 iact->name = "CPU0 Timer";
124 } else {
125 reload_jiffies_counter1(MN10300_JC_PER_HZ - 1);
126 iact->name = "CPU1 Timer";
127 }
128
129 setup_jiffies_interrupt(cd->irq, iact);
130
131 return 0;
132 }
133