/* * 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/syscore_ops.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 IRQS_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; raw_spin_lock_irqsave(&desc->lock, flags); __disable_irq(desc, irq, true); raw_spin_unlock_irqrestore(&desc->lock, flags); } for_each_irq_desc(irq, desc) if (desc->istate & IRQS_SUSPENDED) synchronize_irq(irq); } EXPORT_SYMBOL_GPL(suspend_device_irqs); 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); __enable_irq(desc, irq, true); 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); /** * 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) { /* * Only interrupts which are marked as wakeup source * and have not been disabled before the suspend check * can abort suspend. */ if (irqd_is_wakeup_set(&desc->irq_data)) { if (desc->depth == 1 && desc->istate & IRQS_PENDING) return -EBUSY; continue; } /* * Check the non wakeup interrupts whether they need * to be masked before finally going into suspend * state. That's for hardware which has no wakeup * source configuration facility. The chip * implementation indicates that with * IRQCHIP_MASK_ON_SUSPEND. */ if (desc->istate & IRQS_SUSPENDED && irq_desc_get_chip(desc)->flags & IRQCHIP_MASK_ON_SUSPEND) mask_irq(desc); } return 0; }