/* * kernel/power/main.c - PM subsystem core functionality. * * Copyright (c) 2003 Patrick Mochel * Copyright (c) 2003 Open Source Development Lab * * This file is released under the GPLv2 * */ #include <linux/kobject.h> #include <linux/string.h> #include <linux/resume-trace.h> #include <linux/workqueue.h> #include "power.h" DEFINE_MUTEX(pm_mutex); unsigned int pm_flags; EXPORT_SYMBOL(pm_flags); #ifdef CONFIG_PM_SLEEP /* Routines for PM-transition notifications */ static BLOCKING_NOTIFIER_HEAD(pm_chain_head); int register_pm_notifier(struct notifier_block *nb) { return blocking_notifier_chain_register(&pm_chain_head, nb); } EXPORT_SYMBOL_GPL(register_pm_notifier); int unregister_pm_notifier(struct notifier_block *nb) { return blocking_notifier_chain_unregister(&pm_chain_head, nb); } EXPORT_SYMBOL_GPL(unregister_pm_notifier); int pm_notifier_call_chain(unsigned long val) { return (blocking_notifier_call_chain(&pm_chain_head, val, NULL) == NOTIFY_BAD) ? -EINVAL : 0; } /* If set, devices may be suspended and resumed asynchronously. */ int pm_async_enabled = 1; static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { return sprintf(buf, "%d\n", pm_async_enabled); } static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t n) { unsigned long val; if (strict_strtoul(buf, 10, &val)) return -EINVAL; if (val > 1) return -EINVAL; pm_async_enabled = val; return n; } power_attr(pm_async); #ifdef CONFIG_PM_DEBUG int pm_test_level = TEST_NONE; static const char * const pm_tests[__TEST_AFTER_LAST] = { [TEST_NONE] = "none", [TEST_CORE] = "core", [TEST_CPUS] = "processors", [TEST_PLATFORM] = "platform", [TEST_DEVICES] = "devices", [TEST_FREEZER] = "freezer", }; static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { char *s = buf; int level; for (level = TEST_FIRST; level <= TEST_MAX; level++) if (pm_tests[level]) { if (level == pm_test_level) s += sprintf(s, "[%s] ", pm_tests[level]); else s += sprintf(s, "%s ", pm_tests[level]); } if (s != buf) /* convert the last space to a newline */ *(s-1) = '\n'; return (s - buf); } static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t n) { const char * const *s; int level; char *p; int len; int error = -EINVAL; p = memchr(buf, '\n', n); len = p ? p - buf : n; mutex_lock(&pm_mutex); level = TEST_FIRST; for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++) if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) { pm_test_level = level; error = 0; break; } mutex_unlock(&pm_mutex); return error ? error : n; } power_attr(pm_test); #endif /* CONFIG_PM_DEBUG */ #endif /* CONFIG_PM_SLEEP */ struct kobject *power_kobj; /** * state - control system power state. * * show() returns what states are supported, which is hard-coded to * 'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and * 'disk' (Suspend-to-Disk). * * store() accepts one of those strings, translates it into the * proper enumerated value, and initiates a suspend transition. */ static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { char *s = buf; #ifdef CONFIG_SUSPEND int i; for (i = 0; i < PM_SUSPEND_MAX; i++) { if (pm_states[i] && valid_state(i)) s += sprintf(s,"%s ", pm_states[i]); } #endif #ifdef CONFIG_HIBERNATION s += sprintf(s, "%s\n", "disk"); #else if (s != buf) /* convert the last space to a newline */ *(s-1) = '\n'; #endif return (s - buf); } static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t n) { #ifdef CONFIG_SUSPEND suspend_state_t state = PM_SUSPEND_STANDBY; const char * const *s; #endif char *p; int len; int error = -EINVAL; p = memchr(buf, '\n', n); len = p ? p - buf : n; /* First, check if we are requested to hibernate */ if (len == 4 && !strncmp(buf, "disk", len)) { error = hibernate(); goto Exit; } #ifdef CONFIG_SUSPEND for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) { if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) break; } if (state < PM_SUSPEND_MAX && *s) error = enter_state(state); #endif Exit: return error ? error : n; } power_attr(state); #ifdef CONFIG_PM_TRACE int pm_trace_enabled; static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { return sprintf(buf, "%d\n", pm_trace_enabled); } static ssize_t pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t n) { int val; if (sscanf(buf, "%d", &val) == 1) { pm_trace_enabled = !!val; return n; } return -EINVAL; } power_attr(pm_trace); #endif /* CONFIG_PM_TRACE */ static struct attribute * g[] = { &state_attr.attr, #ifdef CONFIG_PM_TRACE &pm_trace_attr.attr, #endif #ifdef CONFIG_PM_SLEEP &pm_async_attr.attr, #ifdef CONFIG_PM_DEBUG &pm_test_attr.attr, #endif #endif NULL, }; static struct attribute_group attr_group = { .attrs = g, }; #ifdef CONFIG_PM_RUNTIME struct workqueue_struct *pm_wq; EXPORT_SYMBOL_GPL(pm_wq); static int __init pm_start_workqueue(void) { pm_wq = create_freezeable_workqueue("pm"); return pm_wq ? 0 : -ENOMEM; } #else static inline int pm_start_workqueue(void) { return 0; } #endif static int __init pm_init(void) { int error = pm_start_workqueue(); if (error) return error; power_kobj = kobject_create_and_add("power", NULL); if (!power_kobj) return -ENOMEM; return sysfs_create_group(power_kobj, &attr_group); } core_initcall(pm_init);