summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-footbridge/dc21285-timer.c
blob: f76212d2dbf1fed88106325c7fa7f133af01fa6f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/arch/arm/mach-footbridge/dc21285-timer.c
 *
 *  Copyright (C) 1998 Russell King.
 *  Copyright (C) 1998 Phil Blundell
 */
#include <linux/clockchips.h>
#include <linux/clocksource.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/sched_clock.h>

#include <asm/irq.h>

#include <asm/hardware/dec21285.h>
#include <asm/mach/time.h>
#include <asm/system_info.h>

#include "common.h"

static u64 cksrc_dc21285_read(struct clocksource *cs)
{
	return cs->mask - *CSR_TIMER2_VALUE;
}

static int cksrc_dc21285_enable(struct clocksource *cs)
{
	*CSR_TIMER2_LOAD = cs->mask;
	*CSR_TIMER2_CLR = 0;
	*CSR_TIMER2_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_DIV16;
	return 0;
}

static void cksrc_dc21285_disable(struct clocksource *cs)
{
	*CSR_TIMER2_CNTL = 0;
}

static struct clocksource cksrc_dc21285 = {
	.name		= "dc21285_timer2",
	.rating		= 200,
	.read		= cksrc_dc21285_read,
	.enable		= cksrc_dc21285_enable,
	.disable	= cksrc_dc21285_disable,
	.mask		= CLOCKSOURCE_MASK(24),
	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
};

static int ckevt_dc21285_set_next_event(unsigned long delta,
	struct clock_event_device *c)
{
	*CSR_TIMER1_CLR = 0;
	*CSR_TIMER1_LOAD = delta;
	*CSR_TIMER1_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_DIV16;

	return 0;
}

static int ckevt_dc21285_shutdown(struct clock_event_device *c)
{
	*CSR_TIMER1_CNTL = 0;
	return 0;
}

static int ckevt_dc21285_set_periodic(struct clock_event_device *c)
{
	*CSR_TIMER1_CLR = 0;
	*CSR_TIMER1_LOAD = (mem_fclk_21285 + 8 * HZ) / (16 * HZ);
	*CSR_TIMER1_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_AUTORELOAD |
			   TIMER_CNTL_DIV16;
	return 0;
}

static struct clock_event_device ckevt_dc21285 = {
	.name			= "dc21285_timer1",
	.features		= CLOCK_EVT_FEAT_PERIODIC |
				  CLOCK_EVT_FEAT_ONESHOT,
	.rating			= 200,
	.irq			= IRQ_TIMER1,
	.set_next_event		= ckevt_dc21285_set_next_event,
	.set_state_shutdown	= ckevt_dc21285_shutdown,
	.set_state_periodic	= ckevt_dc21285_set_periodic,
	.set_state_oneshot	= ckevt_dc21285_shutdown,
	.tick_resume		= ckevt_dc21285_set_periodic,
};

static irqreturn_t timer1_interrupt(int irq, void *dev_id)
{
	struct clock_event_device *ce = dev_id;

	*CSR_TIMER1_CLR = 0;

	/* Stop the timer if in one-shot mode */
	if (clockevent_state_oneshot(ce))
		*CSR_TIMER1_CNTL = 0;

	ce->event_handler(ce);

	return IRQ_HANDLED;
}

static struct irqaction footbridge_timer_irq = {
	.name		= "dc21285_timer1",
	.handler	= timer1_interrupt,
	.flags		= IRQF_TIMER | IRQF_IRQPOLL,
	.dev_id		= &ckevt_dc21285,
};

/*
 * Set up timer interrupt.
 */
void __init footbridge_timer_init(void)
{
	struct clock_event_device *ce = &ckevt_dc21285;
	unsigned rate = DIV_ROUND_CLOSEST(mem_fclk_21285, 16);

	clocksource_register_hz(&cksrc_dc21285, rate);

	setup_irq(ce->irq, &footbridge_timer_irq);

	ce->cpumask = cpumask_of(smp_processor_id());
	clockevents_config_and_register(ce, rate, 0x4, 0xffffff);
}

static u64 notrace footbridge_read_sched_clock(void)
{
	return ~*CSR_TIMER3_VALUE;
}

void __init footbridge_sched_clock(void)
{
	unsigned rate = DIV_ROUND_CLOSEST(mem_fclk_21285, 16);

	*CSR_TIMER3_LOAD = 0;
	*CSR_TIMER3_CLR = 0;
	*CSR_TIMER3_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_DIV16;

	sched_clock_register(footbridge_read_sched_clock, 24, rate);
}