1// SPDX-License-Identifier: GPL-2.0
2/*
3 * wakeup.c - support wakeup devices
4 * 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 in
26 * suspend/resume and isn't really required as this is called in S-state. At
27 * that time, there is no device hotplug
28 **/
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 set
35 * the wakeup enable mask bits in the GPE registers that correspond to wakeup
36 * 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.valid
45 || sleep_state > dev->wakeup.sleep_state
46 || !(device_may_wakeup(dev: &dev->dev)
47 || dev->wakeup.prepare_count))
48 continue;
49
50 if (device_may_wakeup(dev: &dev->dev))
51 acpi_enable_wakeup_device_power(dev, state: sleep_state);
52
53 /* The wake-up power should have been enabled already. */
54 acpi_set_gpe_wake_mask(gpe_device: dev->wakeup.gpe_device, gpe_number: 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.valid
70 || sleep_state > dev->wakeup.sleep_state
71 || !(device_may_wakeup(dev: &dev->dev)
72 || dev->wakeup.prepare_count))
73 continue;
74
75 acpi_set_gpe_wake_mask(gpe_device: dev->wakeup.gpe_device, gpe_number: dev->wakeup.gpe_number,
76 ACPI_GPE_DISABLE);
77
78 if (device_may_wakeup(dev: &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(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->dev)) {
91 /* Button GPEs are supposed to be always enabled. */
92 acpi_enable_gpe(gpe_device: dev->wakeup.gpe_device,
93 gpe_number: dev->wakeup.gpe_number);
94 device_set_wakeup_enable(dev: &dev->dev, enable: true);
95 }
96 }
97 mutex_unlock(lock: &acpi_device_lock);
98 return 0;
99}
100
101/**
102 * acpi_register_wakeup_handler - Register wakeup handler
103 * @wake_irq: The IRQ through which the device may receive wakeups
104 * @wakeup: Wakeup-handler to call when the SCI has triggered a wakeup
105 * @context: Context to pass to the handler when calling it
106 *
107 * Drivers which may share an IRQ with the SCI can use this to register
108 * a handler which returns true when the device they are managing wants
109 * 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 no
118 * 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(lock: &acpi_wakeup_handler_mutex);
131 list_add(new: &handler->list_node, head: &acpi_wakeup_handler_head);
132 mutex_unlock(lock: &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 handler
140 * @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(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(entry: &handler->list_node);
152 kfree(objp: handler);
153 break;
154 }
155 }
156 mutex_unlock(lock: &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