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 #include <linux/syscore_ops.h> 13 14 #include "internals.h" 15 16 /** 17 * suspend_device_irqs - disable all currently enabled interrupt lines 18 * 19 * During system-wide suspend or hibernation device drivers need to be prevented 20 * from receiving interrupts and this function is provided for this purpose. 21 * It marks all interrupt lines in use, except for the timer ones, as disabled 22 * and sets the IRQS_SUSPENDED flag for each of them. 23 */ 24 void suspend_device_irqs(void) 25 { 26 struct irq_desc *desc; 27 int irq; 28 29 for_each_irq_desc(irq, desc) { 30 unsigned long flags; 31 32 raw_spin_lock_irqsave(&desc->lock, flags); 33 __disable_irq(desc, irq, true); 34 raw_spin_unlock_irqrestore(&desc->lock, flags); 35 } 36 37 for_each_irq_desc(irq, desc) 38 if (desc->istate & IRQS_SUSPENDED) 39 synchronize_irq(irq); 40 } 41 EXPORT_SYMBOL_GPL(suspend_device_irqs); 42 43 static void resume_irqs(bool want_early) 44 { 45 struct irq_desc *desc; 46 int irq; 47 48 for_each_irq_desc(irq, desc) { 49 unsigned long flags; 50 bool is_early = desc->action && 51 desc->action->flags & IRQF_EARLY_RESUME; 52 53 if (is_early != want_early) 54 continue; 55 56 raw_spin_lock_irqsave(&desc->lock, flags); 57 __enable_irq(desc, irq, true); 58 raw_spin_unlock_irqrestore(&desc->lock, flags); 59 } 60 } 61 62 /** 63 * irq_pm_syscore_ops - enable interrupt lines early 64 * 65 * Enable all interrupt lines with %IRQF_EARLY_RESUME set. 66 */ 67 static void irq_pm_syscore_resume(void) 68 { 69 resume_irqs(true); 70 } 71 72 static struct syscore_ops irq_pm_syscore_ops = { 73 .resume = irq_pm_syscore_resume, 74 }; 75 76 static int __init irq_pm_init_ops(void) 77 { 78 register_syscore_ops(&irq_pm_syscore_ops); 79 return 0; 80 } 81 82 device_initcall(irq_pm_init_ops); 83 84 /** 85 * resume_device_irqs - enable interrupt lines disabled by suspend_device_irqs() 86 * 87 * Enable all non-%IRQF_EARLY_RESUME interrupt lines previously 88 * disabled by suspend_device_irqs() that have the IRQS_SUSPENDED flag 89 * set as well as those with %IRQF_FORCE_RESUME. 90 */ 91 void resume_device_irqs(void) 92 { 93 resume_irqs(false); 94 } 95 EXPORT_SYMBOL_GPL(resume_device_irqs); 96 97 /** 98 * check_wakeup_irqs - check if any wake-up interrupts are pending 99 */ 100 int check_wakeup_irqs(void) 101 { 102 struct irq_desc *desc; 103 int irq; 104 105 for_each_irq_desc(irq, desc) { 106 /* 107 * Only interrupts which are marked as wakeup source 108 * and have not been disabled before the suspend check 109 * can abort suspend. 110 */ 111 if (irqd_is_wakeup_set(&desc->irq_data)) { 112 if (desc->depth == 1 && desc->istate & IRQS_PENDING) 113 return -EBUSY; 114 continue; 115 } 116 /* 117 * Check the non wakeup interrupts whether they need 118 * to be masked before finally going into suspend 119 * state. That's for hardware which has no wakeup 120 * source configuration facility. The chip 121 * implementation indicates that with 122 * IRQCHIP_MASK_ON_SUSPEND. 123 */ 124 if (desc->istate & IRQS_SUSPENDED && 125 irq_desc_get_chip(desc)->flags & IRQCHIP_MASK_ON_SUSPEND) 126 mask_irq(desc); 127 } 128 129 return 0; 130 } 131