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
  13 #include "internals.h"
  14
  15 /**
  16  * suspend_device_irqs - disable all currently enabled interrupt lines
  17  *
  18  * During system-wide suspend or hibernation device drivers need to be prevented
  19  * from receiving interrupts and this function is provided for this purpose.
  20  * It marks all interrupt lines in use, except for the timer ones, as disabled
  21  * and sets the IRQ_SUSPENDED flag for each of them.
  22  */
  23 void suspend_device_irqs(void)
  24 {
  25         struct irq_desc *desc;
  26         int irq;
  27
  28         for_each_irq_desc(irq, desc) {
  29                 unsigned long flags;
  30
  31                 spin_lock_irqsave(&desc->lock, flags);
  32                 __disable_irq(desc, irq, true);
  33                 spin_unlock_irqrestore(&desc->lock, flags);
  34         }
  35
  36         for_each_irq_desc(irq, desc)
  37                 if (desc->status & IRQ_SUSPENDED)
  38                         synchronize_irq(irq);
  39 }
  40 EXPORT_SYMBOL_GPL(suspend_device_irqs);
  41
  42 static void resume_irqs(bool want_early)
  43 {
  44         struct irq_desc *desc;
  45         int irq;
  46
  47         for_each_irq_desc(irq, desc) {
  48                 unsigned long flags;
  49                 bool is_early = desc->action &&
  50                         desc->action->flags & IRQF_EARLY_RESUME;
  51
  52                 if (is_early != want_early)
  53                         continue;
  54
  55                 spin_lock_irqsave(&desc->lock, flags);
  56                 __enable_irq(desc, irq, true);
  57                 spin_unlock_irqrestore(&desc->lock, flags);
  58         }
  59 }
  60
  61 /**
  62  * irq_pm_syscore_ops - enable interrupt lines early
  63  *
  64  * Enable all interrupt lines with %IRQF_EARLY_RESUME set.
  65  */
  66 void irq_pm_syscore_resume(void)
  67 {
  68         resume_irqs(true);
  69 }
  70
  71 /**
  72  * resume_device_irqs - enable interrupt lines disabled by suspend_device_irqs()
  73  *
  74  * Enable all non-%IRQF_EARLY_RESUME interrupt lines previously
  75  * disabled by suspend_device_irqs() that have the IRQS_SUSPENDED flag
  76  * set as well as those with %IRQF_FORCE_RESUME.
  77  */
  78 void resume_device_irqs(void)
  79 {
  80         resume_irqs(false);
  81 }
  82 EXPORT_SYMBOL_GPL(resume_device_irqs);
  83
  84 /**
  85  * check_wakeup_irqs - check if any wake-up interrupts are pending
  86  */
  87 int check_wakeup_irqs(void)
  88 {
  89         struct irq_desc *desc;
  90         int irq;
  91
  92         for_each_irq_desc(irq, desc)
  93                 if ((desc->status & IRQ_WAKEUP) && (desc->status & IRQ_PENDING))
  94                         return -EBUSY;
  95
  96         return 0;
  97 }