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
29static 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
44static DEFINE_PER_CPU(struct clock_event_device, mn10300_clockevent_device);
45static DEFINE_PER_CPU(struct irqaction, timer_irq);
46
47static 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
63static void event_handler(struct clock_event_device *dev)
64{
65}
66
67static 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
77int __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