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1// SPDX-License-Identifier: GPL-2.02/*3 * wakeup.c - support wakeup devices4 * Copyright (C) 2004 Li Shaohua <shaohua.li@intel.com>5 */6 7#include <linux/init.h>8#include <linux/acpi.h>9#include <linux/kernel.h>10#include <linux/types.h>11 12#include "internal.h"13#include "sleep.h"14 15struct acpi_wakeup_handler {16 struct list_head list_node;17 bool (*wakeup)(void *context);18 void *context;19};20 21static LIST_HEAD(acpi_wakeup_handler_head);22static DEFINE_MUTEX(acpi_wakeup_handler_mutex);23 24/*25 * We didn't lock acpi_device_lock in the file, because it invokes oops in26 * suspend/resume and isn't really required as this is called in S-state. At27 * that time, there is no device hotplug28 **/29 30/**31 * acpi_enable_wakeup_devices - Enable wake-up device GPEs.32 * @sleep_state: ACPI system sleep state.33 *34 * Enable wakeup device power of devices with the state.enable flag set and set35 * the wakeup enable mask bits in the GPE registers that correspond to wakeup36 * devices.37 */38void acpi_enable_wakeup_devices(u8 sleep_state)39{40 struct acpi_device *dev, *tmp;41 42 list_for_each_entry_safe(dev, tmp, &acpi_wakeup_device_list,43 wakeup_list) {44 if (!dev->wakeup.flags.valid45 || sleep_state > (u32) dev->wakeup.sleep_state46 || !(device_may_wakeup(&dev->dev)47 || dev->wakeup.prepare_count))48 continue;49 50 if (device_may_wakeup(&dev->dev))51 acpi_enable_wakeup_device_power(dev, sleep_state);52 53 /* The wake-up power should have been enabled already. */54 acpi_set_gpe_wake_mask(dev->wakeup.gpe_device, dev->wakeup.gpe_number,55 ACPI_GPE_ENABLE);56 }57}58 59/**60 * acpi_disable_wakeup_devices - Disable devices' wakeup capability.61 * @sleep_state: ACPI system sleep state.62 */63void acpi_disable_wakeup_devices(u8 sleep_state)64{65 struct acpi_device *dev, *tmp;66 67 list_for_each_entry_safe(dev, tmp, &acpi_wakeup_device_list,68 wakeup_list) {69 if (!dev->wakeup.flags.valid70 || sleep_state > (u32) dev->wakeup.sleep_state71 || !(device_may_wakeup(&dev->dev)72 || dev->wakeup.prepare_count))73 continue;74 75 acpi_set_gpe_wake_mask(dev->wakeup.gpe_device, dev->wakeup.gpe_number,76 ACPI_GPE_DISABLE);77 78 if (device_may_wakeup(&dev->dev))79 acpi_disable_wakeup_device_power(dev);80 }81}82 83int __init acpi_wakeup_device_init(void)84{85 struct acpi_device *dev, *tmp;86 87 mutex_lock(&acpi_device_lock);88 list_for_each_entry_safe(dev, tmp, &acpi_wakeup_device_list,89 wakeup_list) {90 if (device_can_wakeup(&dev->dev)) {91 /* Button GPEs are supposed to be always enabled. */92 acpi_enable_gpe(dev->wakeup.gpe_device,93 dev->wakeup.gpe_number);94 device_set_wakeup_enable(&dev->dev, true);95 }96 }97 mutex_unlock(&acpi_device_lock);98 return 0;99}100 101/**102 * acpi_register_wakeup_handler - Register wakeup handler103 * @wake_irq: The IRQ through which the device may receive wakeups104 * @wakeup: Wakeup-handler to call when the SCI has triggered a wakeup105 * @context: Context to pass to the handler when calling it106 *107 * Drivers which may share an IRQ with the SCI can use this to register108 * a handler which returns true when the device they are managing wants109 * to trigger a wakeup.110 */111int acpi_register_wakeup_handler(int wake_irq, bool (*wakeup)(void *context),112 void *context)113{114 struct acpi_wakeup_handler *handler;115 116 /*117 * If the device is not sharing its IRQ with the SCI, there is no118 * need to register the handler.119 */120 if (!acpi_sci_irq_valid() || wake_irq != acpi_sci_irq)121 return 0;122 123 handler = kmalloc(sizeof(*handler), GFP_KERNEL);124 if (!handler)125 return -ENOMEM;126 127 handler->wakeup = wakeup;128 handler->context = context;129 130 mutex_lock(&acpi_wakeup_handler_mutex);131 list_add(&handler->list_node, &acpi_wakeup_handler_head);132 mutex_unlock(&acpi_wakeup_handler_mutex);133 134 return 0;135}136EXPORT_SYMBOL_GPL(acpi_register_wakeup_handler);137 138/**139 * acpi_unregister_wakeup_handler - Unregister wakeup handler140 * @wakeup: Wakeup-handler passed to acpi_register_wakeup_handler()141 * @context: Context passed to acpi_register_wakeup_handler()142 */143void acpi_unregister_wakeup_handler(bool (*wakeup)(void *context),144 void *context)145{146 struct acpi_wakeup_handler *handler;147 148 mutex_lock(&acpi_wakeup_handler_mutex);149 list_for_each_entry(handler, &acpi_wakeup_handler_head, list_node) {150 if (handler->wakeup == wakeup && handler->context == context) {151 list_del(&handler->list_node);152 kfree(handler);153 break;154 }155 }156 mutex_unlock(&acpi_wakeup_handler_mutex);157}158EXPORT_SYMBOL_GPL(acpi_unregister_wakeup_handler);159 160bool acpi_check_wakeup_handlers(void)161{162 struct acpi_wakeup_handler *handler;163 164 /* No need to lock, nothing else is running when we're called. */165 list_for_each_entry(handler, &acpi_wakeup_handler_head, list_node) {166 if (handler->wakeup(handler->context))167 return true;168 }169 170 return false;171}172