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Merge branches 'acpica', 'acpi-video' and 'device-properties'
[mirror_ubuntu-zesty-kernel.git] / kernel / irq / pm.c
1 /*
2 * linux/kernel/irq/pm.c
3 *
4 * Copyright (C) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
5 *
6 * This file contains power management functions related to interrupts.
7 */
8
9 #include <linux/irq.h>
10 #include <linux/module.h>
11 #include <linux/interrupt.h>
12 #include <linux/suspend.h>
13 #include <linux/syscore_ops.h>
14
15 #include "internals.h"
16
17 bool irq_pm_check_wakeup(struct irq_desc *desc)
18 {
19 if (irqd_is_wakeup_armed(&desc->irq_data)) {
20 irqd_clear(&desc->irq_data, IRQD_WAKEUP_ARMED);
21 desc->istate |= IRQS_SUSPENDED | IRQS_PENDING;
22 desc->depth++;
23 irq_disable(desc);
24 pm_system_irq_wakeup(irq_desc_get_irq(desc));
25 return true;
26 }
27 return false;
28 }
29
30 /*
31 * Called from __setup_irq() with desc->lock held after @action has
32 * been installed in the action chain.
33 */
34 void irq_pm_install_action(struct irq_desc *desc, struct irqaction *action)
35 {
36 desc->nr_actions++;
37
38 if (action->flags & IRQF_FORCE_RESUME)
39 desc->force_resume_depth++;
40
41 WARN_ON_ONCE(desc->force_resume_depth &&
42 desc->force_resume_depth != desc->nr_actions);
43
44 if (action->flags & IRQF_NO_SUSPEND)
45 desc->no_suspend_depth++;
46 else if (action->flags & IRQF_COND_SUSPEND)
47 desc->cond_suspend_depth++;
48
49 WARN_ON_ONCE(desc->no_suspend_depth &&
50 (desc->no_suspend_depth +
51 desc->cond_suspend_depth) != desc->nr_actions);
52 }
53
54 /*
55 * Called from __free_irq() with desc->lock held after @action has
56 * been removed from the action chain.
57 */
58 void irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action)
59 {
60 desc->nr_actions--;
61
62 if (action->flags & IRQF_FORCE_RESUME)
63 desc->force_resume_depth--;
64
65 if (action->flags & IRQF_NO_SUSPEND)
66 desc->no_suspend_depth--;
67 else if (action->flags & IRQF_COND_SUSPEND)
68 desc->cond_suspend_depth--;
69 }
70
71 static bool suspend_device_irq(struct irq_desc *desc)
72 {
73 if (!desc->action || irq_desc_is_chained(desc) ||
74 desc->no_suspend_depth)
75 return false;
76
77 if (irqd_is_wakeup_set(&desc->irq_data)) {
78 irqd_set(&desc->irq_data, IRQD_WAKEUP_ARMED);
79 /*
80 * We return true here to force the caller to issue
81 * synchronize_irq(). We need to make sure that the
82 * IRQD_WAKEUP_ARMED is visible before we return from
83 * suspend_device_irqs().
84 */
85 return true;
86 }
87
88 desc->istate |= IRQS_SUSPENDED;
89 __disable_irq(desc);
90
91 /*
92 * Hardware which has no wakeup source configuration facility
93 * requires that the non wakeup interrupts are masked at the
94 * chip level. The chip implementation indicates that with
95 * IRQCHIP_MASK_ON_SUSPEND.
96 */
97 if (irq_desc_get_chip(desc)->flags & IRQCHIP_MASK_ON_SUSPEND)
98 mask_irq(desc);
99 return true;
100 }
101
102 /**
103 * suspend_device_irqs - disable all currently enabled interrupt lines
104 *
105 * During system-wide suspend or hibernation device drivers need to be
106 * prevented from receiving interrupts and this function is provided
107 * for this purpose.
108 *
109 * So we disable all interrupts and mark them IRQS_SUSPENDED except
110 * for those which are unused, those which are marked as not
111 * suspendable via an interrupt request with the flag IRQF_NO_SUSPEND
112 * set and those which are marked as active wakeup sources.
113 *
114 * The active wakeup sources are handled by the flow handler entry
115 * code which checks for the IRQD_WAKEUP_ARMED flag, suspends the
116 * interrupt and notifies the pm core about the wakeup.
117 */
118 void suspend_device_irqs(void)
119 {
120 struct irq_desc *desc;
121 int irq;
122
123 for_each_irq_desc(irq, desc) {
124 unsigned long flags;
125 bool sync;
126
127 if (irq_settings_is_nested_thread(desc))
128 continue;
129 raw_spin_lock_irqsave(&desc->lock, flags);
130 sync = suspend_device_irq(desc);
131 raw_spin_unlock_irqrestore(&desc->lock, flags);
132
133 if (sync)
134 synchronize_irq(irq);
135 }
136 }
137 EXPORT_SYMBOL_GPL(suspend_device_irqs);
138
139 static void resume_irq(struct irq_desc *desc)
140 {
141 irqd_clear(&desc->irq_data, IRQD_WAKEUP_ARMED);
142
143 if (desc->istate & IRQS_SUSPENDED)
144 goto resume;
145
146 /* Force resume the interrupt? */
147 if (!desc->force_resume_depth)
148 return;
149
150 /* Pretend that it got disabled ! */
151 desc->depth++;
152 resume:
153 desc->istate &= ~IRQS_SUSPENDED;
154 __enable_irq(desc);
155 }
156
157 static void resume_irqs(bool want_early)
158 {
159 struct irq_desc *desc;
160 int irq;
161
162 for_each_irq_desc(irq, desc) {
163 unsigned long flags;
164 bool is_early = desc->action &&
165 desc->action->flags & IRQF_EARLY_RESUME;
166
167 if (!is_early && want_early)
168 continue;
169 if (irq_settings_is_nested_thread(desc))
170 continue;
171
172 raw_spin_lock_irqsave(&desc->lock, flags);
173 resume_irq(desc);
174 raw_spin_unlock_irqrestore(&desc->lock, flags);
175 }
176 }
177
178 /**
179 * irq_pm_syscore_ops - enable interrupt lines early
180 *
181 * Enable all interrupt lines with %IRQF_EARLY_RESUME set.
182 */
183 static void irq_pm_syscore_resume(void)
184 {
185 resume_irqs(true);
186 }
187
188 static struct syscore_ops irq_pm_syscore_ops = {
189 .resume = irq_pm_syscore_resume,
190 };
191
192 static int __init irq_pm_init_ops(void)
193 {
194 register_syscore_ops(&irq_pm_syscore_ops);
195 return 0;
196 }
197
198 device_initcall(irq_pm_init_ops);
199
200 /**
201 * resume_device_irqs - enable interrupt lines disabled by suspend_device_irqs()
202 *
203 * Enable all non-%IRQF_EARLY_RESUME interrupt lines previously
204 * disabled by suspend_device_irqs() that have the IRQS_SUSPENDED flag
205 * set as well as those with %IRQF_FORCE_RESUME.
206 */
207 void resume_device_irqs(void)
208 {
209 resume_irqs(false);
210 }
211 EXPORT_SYMBOL_GPL(resume_device_irqs);