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 void set_clock_mode(enum clock_event_mode mode,
45			   struct clock_event_device *evt)
46{
47	/* Nothing to do ...  */
48}
49
50static DEFINE_PER_CPU(struct clock_event_device, mn10300_clockevent_device);
51static DEFINE_PER_CPU(struct irqaction, timer_irq);
52
53static 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
69static void event_handler(struct clock_event_device *dev)
70{
71}
72
73static inline void setup_jiffies_interrupt(int irq,
74					   struct irqaction *action)
75{
76	u16 tmp;
77	setup_irq(irq, action);
78	set_intr_level(irq, NUM2GxICR_LEVEL(CONFIG_TIMER_IRQ_LEVEL));
79	GxICR(irq) |= GxICR_ENABLE | GxICR_DETECT | GxICR_REQUEST;
80	tmp = GxICR(irq);
81}
82
83int __init init_clockevents(void)
84{
85	struct clock_event_device *cd;
86	struct irqaction *iact;
87	unsigned int cpu = smp_processor_id();
88
89	cd = &per_cpu(mn10300_clockevent_device, cpu);
90
91	if (cpu == 0) {
92		stop_jiffies_counter();
93		cd->irq	= TMJCIRQ;
94	} else {
95		stop_jiffies_counter1();
96		cd->irq	= TMJC1IRQ;
97	}
98
99	cd->name		= "Timestamp";
100	cd->features		= CLOCK_EVT_FEAT_ONESHOT;
101
102	/* Calculate shift/mult. We want to spawn at least 1 second */
103	clockevents_calc_mult_shift(cd, MN10300_JCCLK, 1);
104
105	/* Calculate the min / max delta */
106	cd->max_delta_ns	= clockevent_delta2ns(TMJCBR_MAX, cd);
107	cd->min_delta_ns	= clockevent_delta2ns(100, cd);
108
109	cd->rating		= 200;
110	cd->cpumask		= cpumask_of(smp_processor_id());
111	cd->set_mode		= set_clock_mode;
112	cd->event_handler	= event_handler;
113	cd->set_next_event	= next_event;
114
115	iact = &per_cpu(timer_irq, cpu);
116	iact->flags = IRQF_SHARED | IRQF_TIMER;
117	iact->handler = timer_interrupt;
118
119	clockevents_register_device(cd);
120
121#if defined(CONFIG_SMP) && !defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST)
122	/* setup timer irq affinity so it only runs on this cpu */
123	{
124		struct irq_data *data;
125		data = irq_get_irq_data(cd->irq);
126		cpumask_copy(data->affinity, cpumask_of(cpu));
127		iact->flags |= IRQF_NOBALANCING;
128	}
129#endif
130
131	if (cpu == 0) {
132		reload_jiffies_counter(MN10300_JC_PER_HZ - 1);
133		iact->name = "CPU0 Timer";
134	} else {
135		reload_jiffies_counter1(MN10300_JC_PER_HZ - 1);
136		iact->name = "CPU1 Timer";
137	}
138
139	setup_jiffies_interrupt(cd->irq, iact);
140
141	return 0;
142}
143