2 * kernel/power/suspend.c - Suspend to RAM and standby functionality.
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
6 * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
8 * This file is released under the GPLv2.
11 #include <linux/string.h>
12 #include <linux/delay.h>
13 #include <linux/errno.h>
14 #include <linux/init.h>
15 #include <linux/console.h>
16 #include <linux/cpu.h>
17 #include <linux/syscalls.h>
18 #include <linux/gfp.h>
20 #include <linux/kernel.h>
21 #include <linux/list.h>
23 #include <linux/slab.h>
24 #include <linux/suspend.h>
25 #include <linux/syscore_ops.h>
29 /* Enter deep-idle mode interface */
30 void (*deepidle_start)(void);
32 const char *const pm_states[PM_SUSPEND_MAX] = {
33 [PM_SUSPEND_STANDBY] = "standby",
34 [PM_SUSPEND_DEEPIDLE] = "deepidle",
35 [PM_SUSPEND_MEM] = "mem",
38 static struct platform_suspend_ops *suspend_ops;
41 * suspend_set_ops - Set the global suspend method table.
42 * @ops: Pointer to ops structure.
44 void suspend_set_ops(struct platform_suspend_ops *ops)
46 mutex_lock(&pm_mutex);
48 mutex_unlock(&pm_mutex);
51 bool valid_state(suspend_state_t state)
54 * All states need lowlevel support and need to be valid to the lowlevel
55 * implementation, no valid callback implies that none are valid.
57 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
61 * suspend_valid_only_mem - generic memory-only valid callback
63 * Platform drivers that implement mem suspend only and only need
64 * to check for that in their .valid callback can use this instead
65 * of rolling their own .valid callback.
67 int suspend_valid_only_mem(suspend_state_t state)
69 return state == PM_SUSPEND_MEM;
72 static int suspend_test(int level)
74 #ifdef CONFIG_PM_DEBUG
75 if (pm_test_level == level) {
76 printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
80 #endif /* !CONFIG_PM_DEBUG */
85 * suspend_prepare - Do prep work before entering low-power state.
87 * This is common code that is called for each state that we're entering.
88 * Run suspend notifiers, allocate a console and stop all processes.
90 static int suspend_prepare(void)
94 if (!suspend_ops || !suspend_ops->enter)
99 error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
103 error = usermodehelper_disable();
107 error = suspend_freeze_processes();
111 suspend_thaw_processes();
112 usermodehelper_enable();
114 pm_notifier_call_chain(PM_POST_SUSPEND);
115 pm_restore_console();
119 /* default implementation */
120 void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
125 /* default implementation */
126 void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
132 * suspend_enter - enter the desired system sleep state.
133 * @state: state to enter
134 * @pm_wakeup_pending: indicates that the power transition in progress
137 * This function should be called after devices have been suspended.
139 static int suspend_enter(suspend_state_t state, bool *pm_wakeup_pending)
143 if (suspend_ops->prepare) {
144 error = suspend_ops->prepare();
146 goto Platform_finish;
149 error = dpm_suspend_noirq(PMSG_SUSPEND);
151 printk(KERN_ERR "PM: Some devices failed to power down\n");
152 goto Platform_finish;
155 if (suspend_ops->prepare_late) {
156 error = suspend_ops->prepare_late();
161 if (suspend_test(TEST_PLATFORM))
164 error = disable_nonboot_cpus();
165 if (error || suspend_test(TEST_CPUS))
168 arch_suspend_disable_irqs();
169 BUG_ON(!irqs_disabled());
171 error = sysdev_suspend(PMSG_SUSPEND);
173 error = syscore_suspend();
175 *pm_wakeup_pending = pm_check_wakeup_events();
176 if (!suspend_test(TEST_CORE) && *pm_wakeup_pending) {
177 error = suspend_ops->enter(state);
178 events_check_enabled = false;
184 arch_suspend_enable_irqs();
185 BUG_ON(irqs_disabled());
188 enable_nonboot_cpus();
191 if (suspend_ops->wake)
194 dpm_resume_noirq(PMSG_RESUME);
197 if (suspend_ops->finish)
198 suspend_ops->finish();
204 * suspend_devices_and_enter - suspend devices and enter the desired system
206 * @state: state to enter
208 int suspend_devices_and_enter(suspend_state_t state)
211 bool pm_wakeup_pending = true;
216 if (suspend_ops->begin) {
217 error = suspend_ops->begin(state);
222 pm_restrict_gfp_mask();
223 suspend_test_start();
224 error = dpm_suspend_start(PMSG_SUSPEND);
226 printk(KERN_ERR "PM: Some devices failed to suspend\n");
227 goto Recover_platform;
229 suspend_test_finish("suspend devices");
230 if (suspend_test(TEST_DEVICES))
231 goto Recover_platform;
234 error = suspend_enter(state, &pm_wakeup_pending);
235 } while (suspend_ops->suspend_again && suspend_ops->suspend_again() &&
236 !error && pm_wakeup_pending);
239 suspend_test_start();
240 dpm_resume_end(PMSG_RESUME);
241 suspend_test_finish("resume devices");
242 pm_restore_gfp_mask();
245 if (suspend_ops->end)
250 if (suspend_ops->recover)
251 suspend_ops->recover();
256 * suspend_finish - Do final work before exiting suspend sequence.
258 * Call platform code to clean up, restart processes, and free the
259 * console that we've allocated. This is not called for suspend-to-disk.
261 static void suspend_finish(void)
263 suspend_thaw_processes();
264 usermodehelper_enable();
265 pm_notifier_call_chain(PM_POST_SUSPEND);
266 pm_restore_console();
270 * enter_state - Do common work of entering low-power state.
271 * @state: pm_state structure for state we're entering.
273 * Make sure we're the only ones trying to enter a sleep state. Fail
274 * if someone has beat us to it, since we don't want anything weird to
275 * happen when we wake up.
276 * Then, do the setup for suspend, enter the state, and cleaup (after
279 int enter_state(suspend_state_t state)
283 if (!valid_state(state))
286 if (!mutex_trylock(&pm_mutex))
289 printk(KERN_INFO "PM: Syncing filesystems ... ");
293 pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
294 error = suspend_prepare();
298 if (suspend_test(TEST_FREEZER))
301 pr_debug("PM: Entering %s sleep\n", pm_states[state]);
302 error = suspend_devices_and_enter(state);
305 pr_debug("PM: Finishing wakeup.\n");
308 mutex_unlock(&pm_mutex);
314 * enter_deepidle - Do common work of entering deep-idle state
315 * @state: pm_state structure for state we're entering.
317 * Determine whether or not function pointer is NULL and enter
320 int enter_deepidle(suspend_state_t state)
328 * pm_suspend - Externally visible function for suspending system.
329 * @state: Enumerated value of state to enter.
331 * Determine whether or not value is within range, get state
332 * structure, and enter (above).
334 int pm_suspend(suspend_state_t state)
336 if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
337 return enter_state(state);
340 EXPORT_SYMBOL(pm_suspend);