xref: /linux/drivers/acpi/wakeup.c (revision d9c944463d8f3f7cafaaba8f3e44df62ce817484)
1 /*
2  * wakeup.c - support wakeup devices
3  * Copyright (C) 2004 Li Shaohua <shaohua.li@intel.com>
4  */
5 
6 #include <linux/init.h>
7 #include <linux/acpi.h>
8 #include <acpi/acpi_drivers.h>
9 #include <linux/kernel.h>
10 #include <linux/types.h>
11 
12 #include "internal.h"
13 #include "sleep.h"
14 
15 /*
16  * We didn't lock acpi_device_lock in the file, because it invokes oops in
17  * suspend/resume and isn't really required as this is called in S-state. At
18  * that time, there is no device hotplug
19  **/
20 #define _COMPONENT		ACPI_SYSTEM_COMPONENT
21 ACPI_MODULE_NAME("wakeup_devices")
22 
23 /**
24  * acpi_enable_wakeup_device_prep - Prepare wake-up devices.
25  * @sleep_state: ACPI system sleep state.
26  *
27  * Enable all wake-up devices' power, unless the requested system sleep state is
28  * too deep.
29  */
30 void acpi_enable_wakeup_device_prep(u8 sleep_state)
31 {
32 	struct list_head *node, *next;
33 
34 	list_for_each_safe(node, next, &acpi_wakeup_device_list) {
35 		struct acpi_device *dev = container_of(node,
36 						       struct acpi_device,
37 						       wakeup_list);
38 
39 		if (!dev->wakeup.flags.valid || !dev->wakeup.state.enabled
40 		    || (sleep_state > (u32) dev->wakeup.sleep_state))
41 			continue;
42 
43 		acpi_enable_wakeup_device_power(dev, sleep_state);
44 	}
45 }
46 
47 /**
48  * acpi_enable_wakeup_device - Enable wake-up device GPEs.
49  * @sleep_state: ACPI system sleep state.
50  *
51  * Enable all wake-up devices' GPEs, with the assumption that
52  * acpi_disable_all_gpes() was executed before, so we don't need to disable any
53  * GPEs here.
54  */
55 void acpi_enable_wakeup_device(u8 sleep_state)
56 {
57 	struct list_head *node, *next;
58 
59 	/*
60 	 * Caution: this routine must be invoked when interrupt is disabled
61 	 * Refer ACPI2.0: P212
62 	 */
63 	list_for_each_safe(node, next, &acpi_wakeup_device_list) {
64 		struct acpi_device *dev =
65 			container_of(node, struct acpi_device, wakeup_list);
66 
67 		if (!dev->wakeup.flags.valid)
68 			continue;
69 
70 		if ((!dev->wakeup.state.enabled && !dev->wakeup.prepare_count)
71 		    || sleep_state > (u32) dev->wakeup.sleep_state)
72 			continue;
73 
74 		/* The wake-up power should have been enabled already. */
75 		acpi_set_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number,
76 				ACPI_GPE_ENABLE);
77 	}
78 }
79 
80 /**
81  * acpi_disable_wakeup_device - Disable devices' wakeup capability.
82  * @sleep_state: ACPI system sleep state.
83  *
84  * This function only affects devices with wakeup.state.enabled set, which means
85  * that it reverses the changes made by acpi_enable_wakeup_device_prep().
86  */
87 void acpi_disable_wakeup_device(u8 sleep_state)
88 {
89 	struct list_head *node, *next;
90 
91 	list_for_each_safe(node, next, &acpi_wakeup_device_list) {
92 		struct acpi_device *dev =
93 			container_of(node, struct acpi_device, wakeup_list);
94 
95 		if (!dev->wakeup.flags.valid || !dev->wakeup.state.enabled
96 		    || (sleep_state > (u32) dev->wakeup.sleep_state))
97 			continue;
98 
99 		acpi_disable_wakeup_device_power(dev);
100 	}
101 }
102 
103 int __init acpi_wakeup_device_init(void)
104 {
105 	struct list_head *node, *next;
106 
107 	mutex_lock(&acpi_device_lock);
108 	list_for_each_safe(node, next, &acpi_wakeup_device_list) {
109 		struct acpi_device *dev = container_of(node,
110 						       struct acpi_device,
111 						       wakeup_list);
112 		/* In case user doesn't load button driver */
113 		if (!dev->wakeup.flags.always_enabled ||
114 		    dev->wakeup.state.enabled)
115 			continue;
116  		acpi_enable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number,
117  				ACPI_GPE_TYPE_WAKE);
118 		dev->wakeup.state.enabled = 1;
119 	}
120 	mutex_unlock(&acpi_device_lock);
121 	return 0;
122 }
123