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