/* * 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 "internals.h" /** * 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. * It marks all interrupt lines in use, except for the timer ones, as disabled * and sets the IRQ_SUSPENDED flag for each of them. */ void suspend_device_irqs(void) { struct irq_desc *desc; int irq; for_each_irq_desc(irq, desc) { unsigned long flags; spin_lock_irqsave(&desc->lock, flags); __disable_irq(desc, irq, true); spin_unlock_irqrestore(&desc->lock, flags); } for_each_irq_desc(irq, desc) if (desc->status & IRQ_SUSPENDED) synchronize_irq(irq); } EXPORT_SYMBOL_GPL(suspend_device_irqs); /** * resume_device_irqs - enable interrupt lines disabled by suspend_device_irqs() * * Enable all interrupt lines previously disabled by suspend_device_irqs() that * have the IRQ_SUSPENDED flag set. */ void resume_device_irqs(void) { struct irq_desc *desc; int irq; for_each_irq_desc(irq, desc) { unsigned long flags; if (!(desc->status & IRQ_SUSPENDED)) continue; spin_lock_irqsave(&desc->lock, flags); __enable_irq(desc, irq, true); spin_unlock_irqrestore(&desc->lock, flags); } } EXPORT_SYMBOL_GPL(resume_device_irqs); /** * check_wakeup_irqs - check if any wake-up interrupts are pending */ int check_wakeup_irqs(void) { struct irq_desc *desc; int irq; for_each_irq_desc(irq, desc) if ((desc->status & IRQ_WAKEUP) && (desc->status & IRQ_PENDING)) return -EBUSY; return 0; }