aboutsummaryrefslogtreecommitdiff
path: root/drivers/acpi/wakeup.c
blob: 0b2e42530adf479b5f7f56f7f6d39de8b9a9ce9b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
// SPDX-License-Identifier: GPL-2.0
/*
 * wakeup.c - support wakeup devices
 * Copyright (C) 2004 Li Shaohua <shaohua.li@intel.com>
 */

#include <linux/init.h>
#include <linux/acpi.h>
#include <linux/kernel.h>
#include <linux/types.h>

#include "internal.h"
#include "sleep.h"

struct acpi_wakeup_handler {
	struct list_head list_node;
	bool (*wakeup)(void *context);
	void *context;
};

static LIST_HEAD(acpi_wakeup_handler_head);
static DEFINE_MUTEX(acpi_wakeup_handler_mutex);

/*
 * We didn't lock acpi_device_lock in the file, because it invokes oops in
 * suspend/resume and isn't really required as this is called in S-state. At
 * that time, there is no device hotplug
 **/
#define _COMPONENT		ACPI_SYSTEM_COMPONENT
ACPI_MODULE_NAME("wakeup_devices")

/**
 * acpi_enable_wakeup_devices - Enable wake-up device GPEs.
 * @sleep_state: ACPI system sleep state.
 *
 * Enable wakeup device power of devices with the state.enable flag set and set
 * the wakeup enable mask bits in the GPE registers that correspond to wakeup
 * devices.
 */
void acpi_enable_wakeup_devices(u8 sleep_state)
{
	struct acpi_device *dev, *tmp;

	list_for_each_entry_safe(dev, tmp, &acpi_wakeup_device_list,
				 wakeup_list) {
		if (!dev->wakeup.flags.valid
		    || sleep_state > (u32) dev->wakeup.sleep_state
		    || !(device_may_wakeup(&dev->dev)
		        || dev->wakeup.prepare_count))
			continue;

		if (device_may_wakeup(&dev->dev))
			acpi_enable_wakeup_device_power(dev, sleep_state);

		/* The wake-up power should have been enabled already. */
		acpi_set_gpe_wake_mask(dev->wakeup.gpe_device, dev->wakeup.gpe_number,
				ACPI_GPE_ENABLE);
	}
}

/**
 * acpi_disable_wakeup_devices - Disable devices' wakeup capability.
 * @sleep_state: ACPI system sleep state.
 */
void acpi_disable_wakeup_devices(u8 sleep_state)
{
	struct acpi_device *dev, *tmp;

	list_for_each_entry_safe(dev, tmp, &acpi_wakeup_device_list,
				 wakeup_list) {
		if (!dev->wakeup.flags.valid
		    || sleep_state > (u32) dev->wakeup.sleep_state
		    || !(device_may_wakeup(&dev->dev)
		        || dev->wakeup.prepare_count))
			continue;

		acpi_set_gpe_wake_mask(dev->wakeup.gpe_device, dev->wakeup.gpe_number,
				ACPI_GPE_DISABLE);

		if (device_may_wakeup(&dev->dev))
			acpi_disable_wakeup_device_power(dev);
	}
}

int __init acpi_wakeup_device_init(void)
{
	struct acpi_device *dev, *tmp;

	mutex_lock(&acpi_device_lock);
	list_for_each_entry_safe(dev, tmp, &acpi_wakeup_device_list,
				 wakeup_list) {
		if (device_can_wakeup(&dev->dev)) {
			/* Button GPEs are supposed to be always enabled. */
			acpi_enable_gpe(dev->wakeup.gpe_device,
					dev->wakeup.gpe_number);
			device_set_wakeup_enable(&dev->dev, true);
		}
	}
	mutex_unlock(&acpi_device_lock);
	return 0;
}

/**
 * acpi_register_wakeup_handler - Register wakeup handler
 * @wake_irq: The IRQ through which the device may receive wakeups
 * @wakeup:   Wakeup-handler to call when the SCI has triggered a wakeup
 * @context:  Context to pass to the handler when calling it
 *
 * Drivers which may share an IRQ with the SCI can use this to register
 * a handler which returns true when the device they are managing wants
 * to trigger a wakeup.
 */
int acpi_register_wakeup_handler(int wake_irq, bool (*wakeup)(void *context),
				 void *context)
{
	struct acpi_wakeup_handler *handler;

	/*
	 * If the device is not sharing its IRQ with the SCI, there is no
	 * need to register the handler.
	 */
	if (!acpi_sci_irq_valid() || wake_irq != acpi_sci_irq)
		return 0;

	handler = kmalloc(sizeof(*handler), GFP_KERNEL);
	if (!handler)
		return -ENOMEM;

	handler->wakeup = wakeup;
	handler->context = context;

	mutex_lock(&acpi_wakeup_handler_mutex);
	list_add(&handler->list_node, &acpi_wakeup_handler_head);
	mutex_unlock(&acpi_wakeup_handler_mutex);

	return 0;
}
EXPORT_SYMBOL_GPL(acpi_register_wakeup_handler);

/**
 * acpi_unregister_wakeup_handler - Unregister wakeup handler
 * @wakeup:   Wakeup-handler passed to acpi_register_wakeup_handler()
 * @context:  Context passed to acpi_register_wakeup_handler()
 */
void acpi_unregister_wakeup_handler(bool (*wakeup)(void *context),
				    void *context)
{
	struct acpi_wakeup_handler *handler;

	mutex_lock(&acpi_wakeup_handler_mutex);
	list_for_each_entry(handler, &acpi_wakeup_handler_head, list_node) {
		if (handler->wakeup == wakeup && handler->context == context) {
			list_del(&handler->list_node);
			kfree(handler);
			break;
		}
	}
	mutex_unlock(&acpi_wakeup_handler_mutex);
}
EXPORT_SYMBOL_GPL(acpi_unregister_wakeup_handler);

bool acpi_check_wakeup_handlers(void)
{
	struct acpi_wakeup_handler *handler;

	/* No need to lock, nothing else is running when we're called. */
	list_for_each_entry(handler, &acpi_wakeup_handler_head, list_node) {
		if (handler->wakeup(handler->context))
			return true;
	}

	return false;
}