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
44 static DEFINE_PER_CPU(struct clock_event_device, mn10300_clockevent_device);
45 static DEFINE_PER_CPU(struct irqaction, timer_irq);
46
timer_interrupt(int irq,void * dev_id)47 static irqreturn_t timer_interrupt(int irq, void *dev_id)
48 {
49 struct clock_event_device *cd;
50 unsigned int cpu = smp_processor_id();
51
52 if (cpu == 0)
53 stop_jiffies_counter();
54 else
55 stop_jiffies_counter1();
56
57 cd = &per_cpu(mn10300_clockevent_device, cpu);
58 cd->event_handler(cd);
59
60 return IRQ_HANDLED;
61 }
62
event_handler(struct clock_event_device * dev)63 static void event_handler(struct clock_event_device *dev)
64 {
65 }
66
setup_jiffies_interrupt(int irq,struct irqaction * action)67 static inline void setup_jiffies_interrupt(int irq,
68 struct irqaction *action)
69 {
70 u16 tmp;
71 setup_irq(irq, action);
72 set_intr_level(irq, NUM2GxICR_LEVEL(CONFIG_TIMER_IRQ_LEVEL));
73 GxICR(irq) |= GxICR_ENABLE | GxICR_DETECT | GxICR_REQUEST;
74 tmp = GxICR(irq);
75 }
76
init_clockevents(void)77 int __init init_clockevents(void)
78 {
79 struct clock_event_device *cd;
80 struct irqaction *iact;
81 unsigned int cpu = smp_processor_id();
82
83 cd = &per_cpu(mn10300_clockevent_device, cpu);
84
85 if (cpu == 0) {
86 stop_jiffies_counter();
87 cd->irq = TMJCIRQ;
88 } else {
89 stop_jiffies_counter1();
90 cd->irq = TMJC1IRQ;
91 }
92
93 cd->name = "Timestamp";
94 cd->features = CLOCK_EVT_FEAT_ONESHOT;
95
96 /* Calculate shift/mult. We want to spawn at least 1 second */
97 clockevents_calc_mult_shift(cd, MN10300_JCCLK, 1);
98
99 /* Calculate the min / max delta */
100 cd->max_delta_ns = clockevent_delta2ns(TMJCBR_MAX, cd);
101 cd->min_delta_ns = clockevent_delta2ns(100, cd);
102
103 cd->rating = 200;
104 cd->cpumask = cpumask_of(smp_processor_id());
105 cd->event_handler = event_handler;
106 cd->set_next_event = next_event;
107
108 iact = &per_cpu(timer_irq, cpu);
109 iact->flags = IRQF_SHARED | IRQF_TIMER;
110 iact->handler = timer_interrupt;
111
112 clockevents_register_device(cd);
113
114 #if defined(CONFIG_SMP) && !defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST)
115 /* setup timer irq affinity so it only runs on this cpu */
116 {
117 struct irq_data *data;
118 data = irq_get_irq_data(cd->irq);
119 cpumask_copy(irq_data_get_affinity_mask(data), cpumask_of(cpu));
120 iact->flags |= IRQF_NOBALANCING;
121 }
122 #endif
123
124 if (cpu == 0) {
125 reload_jiffies_counter(MN10300_JC_PER_HZ - 1);
126 iact->name = "CPU0 Timer";
127 } else {
128 reload_jiffies_counter1(MN10300_JC_PER_HZ - 1);
129 iact->name = "CPU1 Timer";
130 }
131
132 setup_jiffies_interrupt(cd->irq, iact);
133
134 return 0;
135 }
136