diff options
Diffstat (limited to 'kernel/irq/pm.c')
| -rw-r--r-- | kernel/irq/pm.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c new file mode 100644 index 000000000..5204a6d1b --- /dev/null +++ b/kernel/irq/pm.c @@ -0,0 +1,206 @@ +/* + * 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_wakeup(); + 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, int irq) +{ + if (!desc->action || 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, irq); + + /* + * 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; + + raw_spin_lock_irqsave(&desc->lock, flags); + sync = suspend_device_irq(desc, irq); + 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, int irq) +{ + 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, irq); +} + +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); + resume_irq(desc, irq); + 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); |