tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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#define _COMPONENT ACPI_SYSTEM_COMPONENT
30ACPI_MODULE_NAME("wakeup_devices")
31
32/**
33 * acpi_enable_wakeup_devices - Enable wake-up device GPEs.
34 * @sleep_state: ACPI system sleep state.
35 *
36 * Enable wakeup device power of devices with the state.enable flag set and set
37 * the wakeup enable mask bits in the GPE registers that correspond to wakeup
38 * devices.
39 */
40void acpi_enable_wakeup_devices(u8 sleep_state)
41{
42 struct acpi_device *dev, *tmp;
43
44 list_for_each_entry_safe(dev, tmp, &acpi_wakeup_device_list,
45 wakeup_list) {
46 if (!dev->wakeup.flags.valid
47 || sleep_state > (u32) dev->wakeup.sleep_state
48 || !(device_may_wakeup(&dev->dev)
49 || dev->wakeup.prepare_count))
50 continue;
51
52 if (device_may_wakeup(&dev->dev))
53 acpi_enable_wakeup_device_power(dev, sleep_state);
54
55 /* The wake-up power should have been enabled already. */
56 acpi_set_gpe_wake_mask(dev->wakeup.gpe_device, dev->wakeup.gpe_number,
57 ACPI_GPE_ENABLE);
58 }
59}
60
61/**
62 * acpi_disable_wakeup_devices - Disable devices' wakeup capability.
63 * @sleep_state: ACPI system sleep state.
64 */
65void acpi_disable_wakeup_devices(u8 sleep_state)
66{
67 struct acpi_device *dev, *tmp;
68
69 list_for_each_entry_safe(dev, tmp, &acpi_wakeup_device_list,
70 wakeup_list) {
71 if (!dev->wakeup.flags.valid
72 || sleep_state > (u32) dev->wakeup.sleep_state
73 || !(device_may_wakeup(&dev->dev)
74 || dev->wakeup.prepare_count))
75 continue;
76
77 acpi_set_gpe_wake_mask(dev->wakeup.gpe_device, dev->wakeup.gpe_number,
78 ACPI_GPE_DISABLE);
79
80 if (device_may_wakeup(&dev->dev))
81 acpi_disable_wakeup_device_power(dev);
82 }
83}
84
85int __init acpi_wakeup_device_init(void)
86{
87 struct acpi_device *dev, *tmp;
88
89 mutex_lock(&acpi_device_lock);
90 list_for_each_entry_safe(dev, tmp, &acpi_wakeup_device_list,
91 wakeup_list) {
92 if (device_can_wakeup(&dev->dev)) {
93 /* Button GPEs are supposed to be always enabled. */
94 acpi_enable_gpe(dev->wakeup.gpe_device,
95 dev->wakeup.gpe_number);
96 device_set_wakeup_enable(&dev->dev, true);
97 }
98 }
99 mutex_unlock(&acpi_device_lock);
100 return 0;
101}
102
103/**
104 * acpi_register_wakeup_handler - Register wakeup handler
105 * @wake_irq: The IRQ through which the device may receive wakeups
106 * @wakeup: Wakeup-handler to call when the SCI has triggered a wakeup
107 * @context: Context to pass to the handler when calling it
108 *
109 * Drivers which may share an IRQ with the SCI can use this to register
110 * a handler which returns true when the device they are managing wants
111 * to trigger a wakeup.
112 */
113int acpi_register_wakeup_handler(int wake_irq, bool (*wakeup)(void *context),
114 void *context)
115{
116 struct acpi_wakeup_handler *handler;
117
118 /*
119 * If the device is not sharing its IRQ with the SCI, there is no
120 * need to register the handler.
121 */
122 if (!acpi_sci_irq_valid() || wake_irq != acpi_sci_irq)
123 return 0;
124
125 handler = kmalloc(sizeof(*handler), GFP_KERNEL);
126 if (!handler)
127 return -ENOMEM;
128
129 handler->wakeup = wakeup;
130 handler->context = context;
131
132 mutex_lock(&acpi_wakeup_handler_mutex);
133 list_add(&handler->list_node, &acpi_wakeup_handler_head);
134 mutex_unlock(&acpi_wakeup_handler_mutex);
135
136 return 0;
137}
138EXPORT_SYMBOL_GPL(acpi_register_wakeup_handler);
139
140/**
141 * acpi_unregister_wakeup_handler - Unregister wakeup handler
142 * @wakeup: Wakeup-handler passed to acpi_register_wakeup_handler()
143 * @context: Context passed to acpi_register_wakeup_handler()
144 */
145void acpi_unregister_wakeup_handler(bool (*wakeup)(void *context),
146 void *context)
147{
148 struct acpi_wakeup_handler *handler;
149
150 mutex_lock(&acpi_wakeup_handler_mutex);
151 list_for_each_entry(handler, &acpi_wakeup_handler_head, list_node) {
152 if (handler->wakeup == wakeup && handler->context == context) {
153 list_del(&handler->list_node);
154 kfree(handler);
155 break;
156 }
157 }
158 mutex_unlock(&acpi_wakeup_handler_mutex);
159}
160EXPORT_SYMBOL_GPL(acpi_unregister_wakeup_handler);
161
162bool acpi_check_wakeup_handlers(void)
163{
164 struct acpi_wakeup_handler *handler;
165
166 /* No need to lock, nothing else is running when we're called. */
167 list_for_each_entry(handler, &acpi_wakeup_handler_head, list_node) {
168 if (handler->wakeup(handler->context))
169 return true;
170 }
171
172 return false;
173}