/* * 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_irq_wakeup(irq_desc_get_irq(desc)); 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++; else if (action->flags & IRQF_COND_SUSPEND) desc->cond_suspend_depth++; WARN_ON_ONCE(desc->no_suspend_depth && (desc->no_suspend_depth + desc->cond_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--; else if (action->flags & IRQF_COND_SUSPEND) desc->cond_suspend_depth--; } static bool suspend_device_irq(struct irq_desc *desc) { if (!desc->action || irq_desc_is_chained(desc) || 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); /* * 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; if (irq_settings_is_nested_thread(desc)) continue; raw_spin_lock_irqsave(&desc->lock, flags); sync = suspend_device_irq(desc); 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) { 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); } 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; if (irq_settings_is_nested_thread(desc)) continue; raw_spin_lock_irqsave(&desc->lock, flags); resume_irq(desc); 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);