aboutsummaryrefslogtreecommitdiffstats
path: root/kernel/irq/pm.c
blob: 3ca5325927045572edfa7d3eebd79f01b2a4c29a (plain) (blame)
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
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
/*
 * linux/kernel/irq/pm.c
 *
 * Copyright (C) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
 *
 * This file contains power management functions related to interrupts.
 */

#include <linux/irq.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/suspend.h>
#include <linux/syscore_ops.h>

#include "internals.h"

bool irq_pm_check_wakeup(struct irq_desc *desc)
{
	if (irqd_is_wakeup_armed(&desc->irq_data)) {
		irqd_clear(&desc->irq_data, IRQD_WAKEUP_ARMED);
		desc->istate |= IRQS_SUSPENDED | IRQS_PENDING;
		desc->depth++;
		irq_disable(desc);
		pm_system_wakeup();
		return true;
	}
	return false;
}

/*
 * Called from __setup_irq() with desc->lock held after @action has
 * been installed in the action chain.
 */
void irq_pm_install_action(struct irq_desc *desc, struct irqaction *action)
{
	desc->nr_actions++;

	if (action->flags & IRQF_FORCE_RESUME)
		desc->force_resume_depth++;

	WARN_ON_ONCE(desc->force_resume_depth &&
		     desc->force_resume_depth != desc->nr_actions);

	if (action->flags & IRQF_NO_SUSPEND)
		desc->no_suspend_depth++;

	WARN_ON_ONCE(desc->no_suspend_depth &&
		     desc->no_suspend_depth != desc->nr_actions);
}

/*
 * Called from __free_irq() with desc->lock held after @action has
 * been removed from the action chain.
 */
void irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action)
{
	desc->nr_actions--;

	if (action->flags & IRQF_FORCE_RESUME)
		desc->force_resume_depth--;

	if (action->flags & IRQF_NO_SUSPEND)
		desc->no_suspend_depth--;
}

static bool suspend_device_irq(struct irq_desc *desc, int irq)
{
	if (!desc->action || desc->no_suspend_depth)
		return false;

	if (irqd_is_wakeup_set(&desc->irq_data)) {
		irqd_set(&desc->irq_data, IRQD_WAKEUP_ARMED);
		/*
		 * We return true here to force the caller to issue
		 * synchronize_irq(). We need to make sure that the
		 * IRQD_WAKEUP_ARMED is visible before we return from
		 * suspend_device_irqs().
		 */
		return true;
	}

	desc->istate |= IRQS_SUSPENDED;
	__disable_irq(desc, irq);

	/*
	 * Hardware which has no wakeup source configuration facility
	 * requires that the non wakeup interrupts are masked at the
	 * chip level. The chip implementation indicates that with
	 * IRQCHIP_MASK_ON_SUSPEND.
	 */
	if (irq_desc_get_chip(desc)->flags & IRQCHIP_MASK_ON_SUSPEND)
		mask_irq(desc);
	return true;
}

/**
 * suspend_device_irqs - disable all currently enabled interrupt lines
 *
 * During system-wide suspend or hibernation device drivers need to be
 * prevented from receiving interrupts and this function is provided
 * for this purpose.
 *
 * So we disable all interrupts and mark them IRQS_SUSPENDED except
 * for those which are unused, those which are marked as not
 * suspendable via an interrupt request with the flag IRQF_NO_SUSPEND
 * set and those which are marked as active wakeup sources.
 *
 * The active wakeup sources are handled by the flow handler entry
 * code which checks for the IRQD_WAKEUP_ARMED flag, suspends the
 * interrupt and notifies the pm core about the wakeup.
 */
void suspend_device_irqs(void)
{
	struct irq_desc *desc;
	int irq;

	for_each_irq_desc(irq, desc) {
		unsigned long flags;
		bool sync;

		raw_spin_lock_irqsave(&desc->lock, flags);
		sync = suspend_device_irq(desc, irq);
		raw_spin_unlock_irqrestore(&desc->lock, flags);

		if (sync)
			synchronize_irq(irq);
	}
}
EXPORT_SYMBOL_GPL(suspend_device_irqs);

static void resume_irq(struct irq_desc *desc, int irq)
{
	irqd_clear(&desc->irq_data, IRQD_WAKEUP_ARMED);

	if (desc->istate & IRQS_SUSPENDED)
		goto resume;

	/* Force resume the interrupt? */
	if (!desc->force_resume_depth)
		return;

	/* Pretend that it got disabled ! */
	desc->depth++;
resume:
	desc->istate &= ~IRQS_SUSPENDED;
	__enable_irq(desc, irq);
}

static void resume_irqs(bool want_early)
{
	struct irq_desc *desc;
	int irq;

	for_each_irq_desc(irq, desc) {
		unsigned long flags;
		bool is_early = desc->action &&
			desc->action->flags & IRQF_EARLY_RESUME;

		if (!is_early && want_early)
			continue;

		raw_spin_lock_irqsave(&desc->lock, flags);
		resume_irq(desc, irq);
		raw_spin_unlock_irqrestore(&desc->lock, flags);
	}
}

/**
 * irq_pm_syscore_ops - enable interrupt lines early
 *
 * Enable all interrupt lines with %IRQF_EARLY_RESUME set.
 */
static void irq_pm_syscore_resume(void)
{
	resume_irqs(true);
}

static struct syscore_ops irq_pm_syscore_ops = {
	.resume		= irq_pm_syscore_resume,
};

static int __init irq_pm_init_ops(void)
{
	register_syscore_ops(&irq_pm_syscore_ops);
	return 0;
}

device_initcall(irq_pm_init_ops);

/**
 * resume_device_irqs - enable interrupt lines disabled by suspend_device_irqs()
 *
 * Enable all non-%IRQF_EARLY_RESUME interrupt lines previously
 * disabled by suspend_device_irqs() that have the IRQS_SUSPENDED flag
 * set as well as those with %IRQF_FORCE_RESUME.
 */
void resume_device_irqs(void)
{
	resume_irqs(false);
}
EXPORT_SYMBOL_GPL(resume_device_irqs);