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/suspend.h> 13 #include <linux/syscore_ops.h> 14 15 #include "internals.h" 16 17 bool irq_pm_check_wakeup(struct irq_desc *desc) 18 { 19 if (irqd_is_wakeup_armed(&desc->irq_data)) { 20 irqd_clear(&desc->irq_data, IRQD_WAKEUP_ARMED); 21 desc->istate |= IRQS_SUSPENDED | IRQS_PENDING; 22 desc->depth++; 23 irq_disable(desc); 24 pm_system_wakeup(); 25 return true; 26 } 27 return false; 28 } 29 30 /* 31 * Called from __setup_irq() with desc->lock held after @action has 32 * been installed in the action chain. 33 */ 34 void irq_pm_install_action(struct irq_desc *desc, struct irqaction *action) 35 { 36 desc->nr_actions++; 37 38 if (action->flags & IRQF_FORCE_RESUME) 39 desc->force_resume_depth++; 40 41 WARN_ON_ONCE(desc->force_resume_depth && 42 desc->force_resume_depth != desc->nr_actions); 43 44 if (action->flags & IRQF_NO_SUSPEND) 45 desc->no_suspend_depth++; 46 47 WARN_ON_ONCE(desc->no_suspend_depth && 48 desc->no_suspend_depth != desc->nr_actions); 49 } 50 51 /* 52 * Called from __free_irq() with desc->lock held after @action has 53 * been removed from the action chain. 54 */ 55 void irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action) 56 { 57 desc->nr_actions--; 58 59 if (action->flags & IRQF_FORCE_RESUME) 60 desc->force_resume_depth--; 61 62 if (action->flags & IRQF_NO_SUSPEND) 63 desc->no_suspend_depth--; 64 } 65 66 static bool suspend_device_irq(struct irq_desc *desc, int irq) 67 { 68 if (!desc->action || desc->no_suspend_depth) 69 return false; 70 71 if (irqd_is_wakeup_set(&desc->irq_data)) { 72 irqd_set(&desc->irq_data, IRQD_WAKEUP_ARMED); 73 /* 74 * We return true here to force the caller to issue 75 * synchronize_irq(). We need to make sure that the 76 * IRQD_WAKEUP_ARMED is visible before we return from 77 * suspend_device_irqs(). 78 */ 79 return true; 80 } 81 82 desc->istate |= IRQS_SUSPENDED; 83 __disable_irq(desc, irq); 84 85 /* 86 * Hardware which has no wakeup source configuration facility 87 * requires that the non wakeup interrupts are masked at the 88 * chip level. The chip implementation indicates that with 89 * IRQCHIP_MASK_ON_SUSPEND. 90 */ 91 if (irq_desc_get_chip(desc)->flags & IRQCHIP_MASK_ON_SUSPEND) 92 mask_irq(desc); 93 return true; 94 } 95 96 /** 97 * suspend_device_irqs - disable all currently enabled interrupt lines 98 * 99 * During system-wide suspend or hibernation device drivers need to be 100 * prevented from receiving interrupts and this function is provided 101 * for this purpose. 102 * 103 * So we disable all interrupts and mark them IRQS_SUSPENDED except 104 * for those which are unused, those which are marked as not 105 * suspendable via an interrupt request with the flag IRQF_NO_SUSPEND 106 * set and those which are marked as active wakeup sources. 107 * 108 * The active wakeup sources are handled by the flow handler entry 109 * code which checks for the IRQD_WAKEUP_ARMED flag, suspends the 110 * interrupt and notifies the pm core about the wakeup. 111 */ 112 void suspend_device_irqs(void) 113 { 114 struct irq_desc *desc; 115 int irq; 116 117 for_each_irq_desc(irq, desc) { 118 unsigned long flags; 119 bool sync; 120 121 raw_spin_lock_irqsave(&desc->lock, flags); 122 sync = suspend_device_irq(desc, irq); 123 raw_spin_unlock_irqrestore(&desc->lock, flags); 124 125 if (sync) 126 synchronize_irq(irq); 127 } 128 } 129 EXPORT_SYMBOL_GPL(suspend_device_irqs); 130 131 static void resume_irq(struct irq_desc *desc, int irq) 132 { 133 irqd_clear(&desc->irq_data, IRQD_WAKEUP_ARMED); 134 135 if (desc->istate & IRQS_SUSPENDED) 136 goto resume; 137 138 /* Force resume the interrupt? */ 139 if (!desc->force_resume_depth) 140 return; 141 142 /* Pretend that it got disabled ! */ 143 desc->depth++; 144 resume: 145 desc->istate &= ~IRQS_SUSPENDED; 146 __enable_irq(desc, irq); 147 } 148 149 static void resume_irqs(bool want_early) 150 { 151 struct irq_desc *desc; 152 int irq; 153 154 for_each_irq_desc(irq, desc) { 155 unsigned long flags; 156 bool is_early = desc->action && 157 desc->action->flags & IRQF_EARLY_RESUME; 158 159 if (!is_early && want_early) 160 continue; 161 162 raw_spin_lock_irqsave(&desc->lock, flags); 163 resume_irq(desc, irq); 164 raw_spin_unlock_irqrestore(&desc->lock, flags); 165 } 166 } 167 168 /** 169 * irq_pm_syscore_ops - enable interrupt lines early 170 * 171 * Enable all interrupt lines with %IRQF_EARLY_RESUME set. 172 */ 173 static void irq_pm_syscore_resume(void) 174 { 175 resume_irqs(true); 176 } 177 178 static struct syscore_ops irq_pm_syscore_ops = { 179 .resume = irq_pm_syscore_resume, 180 }; 181 182 static int __init irq_pm_init_ops(void) 183 { 184 register_syscore_ops(&irq_pm_syscore_ops); 185 return 0; 186 } 187 188 device_initcall(irq_pm_init_ops); 189 190 /** 191 * resume_device_irqs - enable interrupt lines disabled by suspend_device_irqs() 192 * 193 * Enable all non-%IRQF_EARLY_RESUME interrupt lines previously 194 * disabled by suspend_device_irqs() that have the IRQS_SUSPENDED flag 195 * set as well as those with %IRQF_FORCE_RESUME. 196 */ 197 void resume_device_irqs(void) 198 { 199 resume_irqs(false); 200 } 201 EXPORT_SYMBOL_GPL(resume_device_irqs); 202