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_irq_wakeup(irq_desc_get_irq(desc)); 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 else if (action->flags & IRQF_COND_SUSPEND) 47 desc->cond_suspend_depth++; 48 49 WARN_ON_ONCE(desc->no_suspend_depth && 50 (desc->no_suspend_depth + 51 desc->cond_suspend_depth) != desc->nr_actions); 52 } 53 54 /* 55 * Called from __free_irq() with desc->lock held after @action has 56 * been removed from the action chain. 57 */ 58 void irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action) 59 { 60 desc->nr_actions--; 61 62 if (action->flags & IRQF_FORCE_RESUME) 63 desc->force_resume_depth--; 64 65 if (action->flags & IRQF_NO_SUSPEND) 66 desc->no_suspend_depth--; 67 else if (action->flags & IRQF_COND_SUSPEND) 68 desc->cond_suspend_depth--; 69 } 70 71 static bool suspend_device_irq(struct irq_desc *desc) 72 { 73 if (!desc->action || irq_desc_is_chained(desc) || 74 desc->no_suspend_depth) 75 return false; 76 77 if (irqd_is_wakeup_set(&desc->irq_data)) { 78 irqd_set(&desc->irq_data, IRQD_WAKEUP_ARMED); 79 /* 80 * We return true here to force the caller to issue 81 * synchronize_irq(). We need to make sure that the 82 * IRQD_WAKEUP_ARMED is visible before we return from 83 * suspend_device_irqs(). 84 */ 85 return true; 86 } 87 88 desc->istate |= IRQS_SUSPENDED; 89 __disable_irq(desc); 90 91 /* 92 * Hardware which has no wakeup source configuration facility 93 * requires that the non wakeup interrupts are masked at the 94 * chip level. The chip implementation indicates that with 95 * IRQCHIP_MASK_ON_SUSPEND. 96 */ 97 if (irq_desc_get_chip(desc)->flags & IRQCHIP_MASK_ON_SUSPEND) 98 mask_irq(desc); 99 return true; 100 } 101 102 /** 103 * suspend_device_irqs - disable all currently enabled interrupt lines 104 * 105 * During system-wide suspend or hibernation device drivers need to be 106 * prevented from receiving interrupts and this function is provided 107 * for this purpose. 108 * 109 * So we disable all interrupts and mark them IRQS_SUSPENDED except 110 * for those which are unused, those which are marked as not 111 * suspendable via an interrupt request with the flag IRQF_NO_SUSPEND 112 * set and those which are marked as active wakeup sources. 113 * 114 * The active wakeup sources are handled by the flow handler entry 115 * code which checks for the IRQD_WAKEUP_ARMED flag, suspends the 116 * interrupt and notifies the pm core about the wakeup. 117 */ 118 void suspend_device_irqs(void) 119 { 120 struct irq_desc *desc; 121 int irq; 122 123 for_each_irq_desc(irq, desc) { 124 unsigned long flags; 125 bool sync; 126 127 if (irq_settings_is_nested_thread(desc)) 128 continue; 129 raw_spin_lock_irqsave(&desc->lock, flags); 130 sync = suspend_device_irq(desc); 131 raw_spin_unlock_irqrestore(&desc->lock, flags); 132 133 if (sync) 134 synchronize_irq(irq); 135 } 136 } 137 EXPORT_SYMBOL_GPL(suspend_device_irqs); 138 139 static void resume_irq(struct irq_desc *desc) 140 { 141 irqd_clear(&desc->irq_data, IRQD_WAKEUP_ARMED); 142 143 if (desc->istate & IRQS_SUSPENDED) 144 goto resume; 145 146 /* Force resume the interrupt? */ 147 if (!desc->force_resume_depth) 148 return; 149 150 /* Pretend that it got disabled ! */ 151 desc->depth++; 152 resume: 153 desc->istate &= ~IRQS_SUSPENDED; 154 __enable_irq(desc); 155 } 156 157 static void resume_irqs(bool want_early) 158 { 159 struct irq_desc *desc; 160 int irq; 161 162 for_each_irq_desc(irq, desc) { 163 unsigned long flags; 164 bool is_early = desc->action && 165 desc->action->flags & IRQF_EARLY_RESUME; 166 167 if (!is_early && want_early) 168 continue; 169 if (irq_settings_is_nested_thread(desc)) 170 continue; 171 172 raw_spin_lock_irqsave(&desc->lock, flags); 173 resume_irq(desc); 174 raw_spin_unlock_irqrestore(&desc->lock, flags); 175 } 176 } 177 178 /** 179 * irq_pm_syscore_ops - enable interrupt lines early 180 * 181 * Enable all interrupt lines with %IRQF_EARLY_RESUME set. 182 */ 183 static void irq_pm_syscore_resume(void) 184 { 185 resume_irqs(true); 186 } 187 188 static struct syscore_ops irq_pm_syscore_ops = { 189 .resume = irq_pm_syscore_resume, 190 }; 191 192 static int __init irq_pm_init_ops(void) 193 { 194 register_syscore_ops(&irq_pm_syscore_ops); 195 return 0; 196 } 197 198 device_initcall(irq_pm_init_ops); 199 200 /** 201 * resume_device_irqs - enable interrupt lines disabled by suspend_device_irqs() 202 * 203 * Enable all non-%IRQF_EARLY_RESUME interrupt lines previously 204 * disabled by suspend_device_irqs() that have the IRQS_SUSPENDED flag 205 * set as well as those with %IRQF_FORCE_RESUME. 206 */ 207 void resume_device_irqs(void) 208 { 209 resume_irqs(false); 210 } 211 EXPORT_SYMBOL_GPL(resume_device_irqs); 212