2 * kernel/power/main.c - PM subsystem core functionality.
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
7 * This file is released under the GPLv2
11 #include <linux/kobject.h>
12 #include <linux/string.h>
13 #include <linux/resume-trace.h>
14 #include <linux/workqueue.h>
18 DEFINE_MUTEX(pm_mutex);
20 unsigned int pm_flags;
21 EXPORT_SYMBOL(pm_flags);
23 #ifdef CONFIG_PM_SLEEP
25 /* Routines for PM-transition notifications */
27 static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
29 int register_pm_notifier(struct notifier_block *nb)
31 return blocking_notifier_chain_register(&pm_chain_head, nb);
33 EXPORT_SYMBOL_GPL(register_pm_notifier);
35 int unregister_pm_notifier(struct notifier_block *nb)
37 return blocking_notifier_chain_unregister(&pm_chain_head, nb);
39 EXPORT_SYMBOL_GPL(unregister_pm_notifier);
41 int pm_notifier_call_chain(unsigned long val)
43 return (blocking_notifier_call_chain(&pm_chain_head, val, NULL)
44 == NOTIFY_BAD) ? -EINVAL : 0;
47 /* If set, devices may be suspended and resumed asynchronously. */
48 int pm_async_enabled = 1;
50 static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr,
53 return sprintf(buf, "%d\n", pm_async_enabled);
56 static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr,
57 const char *buf, size_t n)
61 if (strict_strtoul(buf, 10, &val))
67 pm_async_enabled = val;
73 #ifdef CONFIG_PM_DEBUG
74 int pm_test_level = TEST_NONE;
76 static const char * const pm_tests[__TEST_AFTER_LAST] = {
79 [TEST_CPUS] = "processors",
80 [TEST_PLATFORM] = "platform",
81 [TEST_DEVICES] = "devices",
82 [TEST_FREEZER] = "freezer",
85 static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
91 for (level = TEST_FIRST; level <= TEST_MAX; level++)
92 if (pm_tests[level]) {
93 if (level == pm_test_level)
94 s += sprintf(s, "[%s] ", pm_tests[level]);
96 s += sprintf(s, "%s ", pm_tests[level]);
100 /* convert the last space to a newline */
106 static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
107 const char *buf, size_t n)
109 const char * const *s;
115 p = memchr(buf, '\n', n);
116 len = p ? p - buf : n;
118 mutex_lock(&pm_mutex);
121 for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
122 if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
123 pm_test_level = level;
128 mutex_unlock(&pm_mutex);
130 return error ? error : n;
134 #endif /* CONFIG_PM_DEBUG */
136 #endif /* CONFIG_PM_SLEEP */
138 struct kobject *power_kobj;
141 * state - control system power state.
143 * show() returns what states are supported, which is hard-coded to
144 * 'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and
145 * 'disk' (Suspend-to-Disk).
147 * store() accepts one of those strings, translates it into the
148 * proper enumerated value, and initiates a suspend transition.
150 static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
154 #ifdef CONFIG_SUSPEND
157 for (i = 0; i < PM_SUSPEND_MAX; i++) {
158 if (pm_states[i] && valid_state(i))
159 s += sprintf(s,"%s ", pm_states[i]);
162 #ifdef CONFIG_HIBERNATION
163 s += sprintf(s, "%s\n", "disk");
166 /* convert the last space to a newline */
172 static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
173 const char *buf, size_t n)
175 #ifdef CONFIG_SUSPEND
176 suspend_state_t state = PM_SUSPEND_STANDBY;
177 const char * const *s;
183 p = memchr(buf, '\n', n);
184 len = p ? p - buf : n;
186 /* First, check if we are requested to hibernate */
187 if (len == 4 && !strncmp(buf, "disk", len)) {
192 #ifdef CONFIG_SUSPEND
193 for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) {
194 if (*s && len == strlen(*s) && !strncmp(buf, *s, len))
197 if (state < PM_SUSPEND_MAX && *s)
198 error = enter_state(state);
202 return error ? error : n;
207 #ifdef CONFIG_PM_TRACE
208 int pm_trace_enabled;
210 static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
213 return sprintf(buf, "%d\n", pm_trace_enabled);
217 pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr,
218 const char *buf, size_t n)
222 if (sscanf(buf, "%d", &val) == 1) {
223 pm_trace_enabled = !!val;
229 power_attr(pm_trace);
230 #endif /* CONFIG_PM_TRACE */
232 static struct attribute * g[] = {
234 #ifdef CONFIG_PM_TRACE
237 #ifdef CONFIG_PM_SLEEP
239 #ifdef CONFIG_PM_DEBUG
246 static struct attribute_group attr_group = {
250 #ifdef CONFIG_PM_RUNTIME
251 struct workqueue_struct *pm_wq;
252 EXPORT_SYMBOL_GPL(pm_wq);
254 static int __init pm_start_workqueue(void)
256 pm_wq = create_freezeable_workqueue("pm");
258 return pm_wq ? 0 : -ENOMEM;
261 static inline int pm_start_workqueue(void) { return 0; }
264 static int __init pm_init(void)
266 int error = pm_start_workqueue();
269 power_kobj = kobject_create_and_add("power", NULL);
272 return sysfs_create_group(power_kobj, &attr_group);
275 core_initcall(pm_init);