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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * pm.h - Power management interface
3 *
4 * Copyright (C) 2000 Andrew Henroid
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21#ifndef _LINUX_PM_H
22#define _LINUX_PM_H
23
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/list.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
26/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070027 * Callbacks for platform drivers to implement.
28 */
29extern void (*pm_idle)(void);
30extern void (*pm_power_off)(void);
Rafael J. Wysockibd804eb2007-07-19 01:47:40 -070031extern void (*pm_power_off_prepare)(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
Linus Torvalds1da177e2005-04-16 15:20:36 -070033/*
34 * Device power management
35 */
36
37struct device;
38
Pavel Machekca078ba2005-09-03 15:56:57 -070039typedef struct pm_message {
40 int event;
41} pm_message_t;
Linus Torvalds1da177e2005-04-16 15:20:36 -070042
Rafael J. Wysocki1eede072008-05-20 23:00:01 +020043/**
Rafael J. Wysockiadf09492008-10-06 22:46:05 +020044 * struct dev_pm_ops - device PM callbacks
Rafael J. Wysocki1eede072008-05-20 23:00:01 +020045 *
David Brownell82bb67f2006-08-14 23:11:04 -070046 * Several driver power state transitions are externally visible, affecting
47 * the state of pending I/O queues and (for drivers that touch hardware)
48 * interrupts, wakeups, DMA, and other hardware state. There may also be
49 * internal transitions to various low power modes, which are transparent
50 * to the rest of the driver stack (such as a driver that's ON gating off
51 * clocks which are not in active use).
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 *
Rafael J. Wysocki1eede072008-05-20 23:00:01 +020053 * The externally visible transitions are handled with the help of the following
54 * callbacks included in this structure:
55 *
56 * @prepare: Prepare the device for the upcoming transition, but do NOT change
57 * its hardware state. Prevent new children of the device from being
58 * registered after @prepare() returns (the driver's subsystem and
59 * generally the rest of the kernel is supposed to prevent new calls to the
60 * probe method from being made too once @prepare() has succeeded). If
61 * @prepare() detects a situation it cannot handle (e.g. registration of a
62 * child already in progress), it may return -EAGAIN, so that the PM core
63 * can execute it once again (e.g. after the new child has been registered)
64 * to recover from the race condition. This method is executed for all
65 * kinds of suspend transitions and is followed by one of the suspend
66 * callbacks: @suspend(), @freeze(), or @poweroff().
67 * The PM core executes @prepare() for all devices before starting to
68 * execute suspend callbacks for any of them, so drivers may assume all of
69 * the other devices to be present and functional while @prepare() is being
70 * executed. In particular, it is safe to make GFP_KERNEL memory
71 * allocations from within @prepare(). However, drivers may NOT assume
72 * anything about the availability of the user space at that time and it
73 * is not correct to request firmware from within @prepare() (it's too
74 * late to do that). [To work around this limitation, drivers may
75 * register suspend and hibernation notifiers that are executed before the
76 * freezing of tasks.]
77 *
78 * @complete: Undo the changes made by @prepare(). This method is executed for
79 * all kinds of resume transitions, following one of the resume callbacks:
80 * @resume(), @thaw(), @restore(). Also called if the state transition
81 * fails before the driver's suspend callback (@suspend(), @freeze(),
82 * @poweroff()) can be executed (e.g. if the suspend callback fails for one
83 * of the other devices that the PM core has unsuccessfully attempted to
84 * suspend earlier).
85 * The PM core executes @complete() after it has executed the appropriate
86 * resume callback for all devices.
87 *
88 * @suspend: Executed before putting the system into a sleep state in which the
89 * contents of main memory are preserved. Quiesce the device, put it into
90 * a low power state appropriate for the upcoming system state (such as
91 * PCI_D3hot), and enable wakeup events as appropriate.
92 *
93 * @resume: Executed after waking the system up from a sleep state in which the
94 * contents of main memory were preserved. Put the device into the
95 * appropriate state, according to the information saved in memory by the
96 * preceding @suspend(). The driver starts working again, responding to
97 * hardware events and software requests. The hardware may have gone
98 * through a power-off reset, or it may have maintained state from the
99 * previous suspend() which the driver may rely on while resuming. On most
100 * platforms, there are no restrictions on availability of resources like
101 * clocks during @resume().
102 *
103 * @freeze: Hibernation-specific, executed before creating a hibernation image.
104 * Quiesce operations so that a consistent image can be created, but do NOT
105 * otherwise put the device into a low power device state and do NOT emit
106 * system wakeup events. Save in main memory the device settings to be
107 * used by @restore() during the subsequent resume from hibernation or by
108 * the subsequent @thaw(), if the creation of the image or the restoration
109 * of main memory contents from it fails.
110 *
111 * @thaw: Hibernation-specific, executed after creating a hibernation image OR
112 * if the creation of the image fails. Also executed after a failing
113 * attempt to restore the contents of main memory from such an image.
114 * Undo the changes made by the preceding @freeze(), so the device can be
115 * operated in the same way as immediately before the call to @freeze().
116 *
117 * @poweroff: Hibernation-specific, executed after saving a hibernation image.
118 * Quiesce the device, put it into a low power state appropriate for the
119 * upcoming system state (such as PCI_D3hot), and enable wakeup events as
120 * appropriate.
121 *
122 * @restore: Hibernation-specific, executed after restoring the contents of main
123 * memory from a hibernation image. Driver starts working again,
124 * responding to hardware events and software requests. Drivers may NOT
125 * make ANY assumptions about the hardware state right prior to @restore().
126 * On most platforms, there are no restrictions on availability of
127 * resources like clocks during @restore().
128 *
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200129 * @suspend_noirq: Complete the operations of ->suspend() by carrying out any
130 * actions required for suspending the device that need interrupts to be
131 * disabled
132 *
133 * @resume_noirq: Prepare for the execution of ->resume() by carrying out any
134 * actions required for resuming the device that need interrupts to be
135 * disabled
136 *
137 * @freeze_noirq: Complete the operations of ->freeze() by carrying out any
138 * actions required for freezing the device that need interrupts to be
139 * disabled
140 *
141 * @thaw_noirq: Prepare for the execution of ->thaw() by carrying out any
142 * actions required for thawing the device that need interrupts to be
143 * disabled
144 *
145 * @poweroff_noirq: Complete the operations of ->poweroff() by carrying out any
146 * actions required for handling the device that need interrupts to be
147 * disabled
148 *
149 * @restore_noirq: Prepare for the execution of ->restore() by carrying out any
150 * actions required for restoring the operations of the device that need
151 * interrupts to be disabled
152 *
Rafael J. Wysockiadf09492008-10-06 22:46:05 +0200153 * All of the above callbacks, except for @complete(), return error codes.
154 * However, the error codes returned by the resume operations, @resume(),
155 * @thaw(), @restore(), @resume_noirq(), @thaw_noirq(), and @restore_noirq() do
156 * not cause the PM core to abort the resume transition during which they are
157 * returned. The error codes returned in that cases are only printed by the PM
158 * core to the system logs for debugging purposes. Still, it is recommended
159 * that drivers only return error codes from their resume methods in case of an
160 * unrecoverable failure (i.e. when the device being handled refuses to resume
161 * and becomes unusable) to allow us to modify the PM core in the future, so
162 * that it can avoid attempting to handle devices that failed to resume and
163 * their children.
164 *
165 * It is allowed to unregister devices while the above callbacks are being
166 * executed. However, it is not allowed to unregister a device from within any
167 * of its own callbacks.
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200168 */
169
Rafael J. Wysockiadf09492008-10-06 22:46:05 +0200170struct dev_pm_ops {
171 int (*prepare)(struct device *dev);
172 void (*complete)(struct device *dev);
173 int (*suspend)(struct device *dev);
174 int (*resume)(struct device *dev);
175 int (*freeze)(struct device *dev);
176 int (*thaw)(struct device *dev);
177 int (*poweroff)(struct device *dev);
178 int (*restore)(struct device *dev);
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200179 int (*suspend_noirq)(struct device *dev);
180 int (*resume_noirq)(struct device *dev);
181 int (*freeze_noirq)(struct device *dev);
182 int (*thaw_noirq)(struct device *dev);
183 int (*poweroff_noirq)(struct device *dev);
184 int (*restore_noirq)(struct device *dev);
185};
186
187/**
188 * PM_EVENT_ messages
189 *
190 * The following PM_EVENT_ messages are defined for the internal use of the PM
191 * core, in order to provide a mechanism allowing the high level suspend and
192 * hibernation code to convey the necessary information to the device PM core
193 * code:
194 *
195 * ON No transition.
196 *
197 * FREEZE System is going to hibernate, call ->prepare() and ->freeze()
198 * for all devices.
199 *
200 * SUSPEND System is going to suspend, call ->prepare() and ->suspend()
201 * for all devices.
202 *
203 * HIBERNATE Hibernation image has been saved, call ->prepare() and
204 * ->poweroff() for all devices.
205 *
206 * QUIESCE Contents of main memory are going to be restored from a (loaded)
207 * hibernation image, call ->prepare() and ->freeze() for all
208 * devices.
209 *
210 * RESUME System is resuming, call ->resume() and ->complete() for all
211 * devices.
212 *
213 * THAW Hibernation image has been created, call ->thaw() and
214 * ->complete() for all devices.
215 *
216 * RESTORE Contents of main memory have been restored from a hibernation
217 * image, call ->restore() and ->complete() for all devices.
218 *
219 * RECOVER Creation of a hibernation image or restoration of the main
220 * memory contents from a hibernation image has failed, call
221 * ->thaw() and ->complete() for all devices.
Alan Stern8111d1b2008-07-23 21:28:37 -0700222 *
223 * The following PM_EVENT_ messages are defined for internal use by
224 * kernel subsystems. They are never issued by the PM core.
225 *
226 * USER_SUSPEND Manual selective suspend was issued by userspace.
227 *
228 * USER_RESUME Manual selective resume was issued by userspace.
229 *
230 * REMOTE_WAKEUP Remote-wakeup request was received from the device.
231 *
232 * AUTO_SUSPEND Automatic (device idle) runtime suspend was
233 * initiated by the subsystem.
234 *
235 * AUTO_RESUME Automatic (device needed) runtime resume was
236 * requested by a driver.
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200237 */
238
239#define PM_EVENT_ON 0x0000
240#define PM_EVENT_FREEZE 0x0001
241#define PM_EVENT_SUSPEND 0x0002
242#define PM_EVENT_HIBERNATE 0x0004
243#define PM_EVENT_QUIESCE 0x0008
244#define PM_EVENT_RESUME 0x0010
245#define PM_EVENT_THAW 0x0020
246#define PM_EVENT_RESTORE 0x0040
247#define PM_EVENT_RECOVER 0x0080
Alan Stern8111d1b2008-07-23 21:28:37 -0700248#define PM_EVENT_USER 0x0100
249#define PM_EVENT_REMOTE 0x0200
250#define PM_EVENT_AUTO 0x0400
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200251
Alan Stern8111d1b2008-07-23 21:28:37 -0700252#define PM_EVENT_SLEEP (PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
253#define PM_EVENT_USER_SUSPEND (PM_EVENT_USER | PM_EVENT_SUSPEND)
254#define PM_EVENT_USER_RESUME (PM_EVENT_USER | PM_EVENT_RESUME)
Alan Stern7f4f5d42008-11-17 11:14:19 -0500255#define PM_EVENT_REMOTE_RESUME (PM_EVENT_REMOTE | PM_EVENT_RESUME)
Alan Stern8111d1b2008-07-23 21:28:37 -0700256#define PM_EVENT_AUTO_SUSPEND (PM_EVENT_AUTO | PM_EVENT_SUSPEND)
257#define PM_EVENT_AUTO_RESUME (PM_EVENT_AUTO | PM_EVENT_RESUME)
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200258
Alan Stern8111d1b2008-07-23 21:28:37 -0700259#define PMSG_ON ((struct pm_message){ .event = PM_EVENT_ON, })
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200260#define PMSG_FREEZE ((struct pm_message){ .event = PM_EVENT_FREEZE, })
261#define PMSG_QUIESCE ((struct pm_message){ .event = PM_EVENT_QUIESCE, })
262#define PMSG_SUSPEND ((struct pm_message){ .event = PM_EVENT_SUSPEND, })
263#define PMSG_HIBERNATE ((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
264#define PMSG_RESUME ((struct pm_message){ .event = PM_EVENT_RESUME, })
265#define PMSG_THAW ((struct pm_message){ .event = PM_EVENT_THAW, })
266#define PMSG_RESTORE ((struct pm_message){ .event = PM_EVENT_RESTORE, })
267#define PMSG_RECOVER ((struct pm_message){ .event = PM_EVENT_RECOVER, })
Alan Stern7f4f5d42008-11-17 11:14:19 -0500268#define PMSG_USER_SUSPEND ((struct pm_message) \
Alan Stern8111d1b2008-07-23 21:28:37 -0700269 { .event = PM_EVENT_USER_SUSPEND, })
Alan Stern7f4f5d42008-11-17 11:14:19 -0500270#define PMSG_USER_RESUME ((struct pm_message) \
Alan Stern8111d1b2008-07-23 21:28:37 -0700271 { .event = PM_EVENT_USER_RESUME, })
Alan Stern7f4f5d42008-11-17 11:14:19 -0500272#define PMSG_REMOTE_RESUME ((struct pm_message) \
Alan Stern8111d1b2008-07-23 21:28:37 -0700273 { .event = PM_EVENT_REMOTE_RESUME, })
Alan Stern7f4f5d42008-11-17 11:14:19 -0500274#define PMSG_AUTO_SUSPEND ((struct pm_message) \
Alan Stern8111d1b2008-07-23 21:28:37 -0700275 { .event = PM_EVENT_AUTO_SUSPEND, })
Alan Stern7f4f5d42008-11-17 11:14:19 -0500276#define PMSG_AUTO_RESUME ((struct pm_message) \
Alan Stern8111d1b2008-07-23 21:28:37 -0700277 { .event = PM_EVENT_AUTO_RESUME, })
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200278
279/**
280 * Device power management states
281 *
282 * These state labels are used internally by the PM core to indicate the current
283 * status of a device with respect to the PM core operations.
284 *
285 * DPM_ON Device is regarded as operational. Set this way
286 * initially and when ->complete() is about to be called.
287 * Also set when ->prepare() fails.
288 *
289 * DPM_PREPARING Device is going to be prepared for a PM transition. Set
290 * when ->prepare() is about to be called.
291 *
292 * DPM_RESUMING Device is going to be resumed. Set when ->resume(),
293 * ->thaw(), or ->restore() is about to be called.
294 *
295 * DPM_SUSPENDING Device has been prepared for a power transition. Set
296 * when ->prepare() has just succeeded.
297 *
298 * DPM_OFF Device is regarded as inactive. Set immediately after
299 * ->suspend(), ->freeze(), or ->poweroff() has succeeded.
300 * Also set when ->resume()_noirq, ->thaw_noirq(), or
301 * ->restore_noirq() is about to be called.
302 *
303 * DPM_OFF_IRQ Device is in a "deep sleep". Set immediately after
304 * ->suspend_noirq(), ->freeze_noirq(), or
305 * ->poweroff_noirq() has just succeeded.
306 */
307
308enum dpm_state {
309 DPM_INVALID,
310 DPM_ON,
311 DPM_PREPARING,
312 DPM_RESUMING,
313 DPM_SUSPENDING,
314 DPM_OFF,
315 DPM_OFF_IRQ,
316};
317
318struct dev_pm_info {
319 pm_message_t power_state;
320 unsigned can_wakeup:1;
321 unsigned should_wakeup:1;
322 enum dpm_state status; /* Owned by the PM core */
323#ifdef CONFIG_PM_SLEEP
324 struct list_head entry;
325#endif
326};
327
328/*
329 * The PM_EVENT_ messages are also used by drivers implementing the legacy
330 * suspend framework, based on the ->suspend() and ->resume() callbacks common
331 * for suspend and hibernation transitions, according to the rules below.
332 */
333
334/* Necessary, because several drivers use PM_EVENT_PRETHAW */
335#define PM_EVENT_PRETHAW PM_EVENT_QUIESCE
336
337/*
David Brownell82bb67f2006-08-14 23:11:04 -0700338 * One transition is triggered by resume(), after a suspend() call; the
339 * message is implicit:
340 *
341 * ON Driver starts working again, responding to hardware events
342 * and software requests. The hardware may have gone through
343 * a power-off reset, or it may have maintained state from the
344 * previous suspend() which the driver will rely on while
345 * resuming. On most platforms, there are no restrictions on
346 * availability of resources like clocks during resume().
347 *
348 * Other transitions are triggered by messages sent using suspend(). All
349 * these transitions quiesce the driver, so that I/O queues are inactive.
350 * That commonly entails turning off IRQs and DMA; there may be rules
351 * about how to quiesce that are specific to the bus or the device's type.
352 * (For example, network drivers mark the link state.) Other details may
353 * differ according to the message:
354 *
355 * SUSPEND Quiesce, enter a low power device state appropriate for
356 * the upcoming system state (such as PCI_D3hot), and enable
357 * wakeup events as appropriate.
358 *
Rafael J. Wysocki3a2d5b72008-02-23 19:13:25 +0100359 * HIBERNATE Enter a low power device state appropriate for the hibernation
360 * state (eg. ACPI S4) and enable wakeup events as appropriate.
361 *
David Brownell82bb67f2006-08-14 23:11:04 -0700362 * FREEZE Quiesce operations so that a consistent image can be saved;
363 * but do NOT otherwise enter a low power device state, and do
364 * NOT emit system wakeup events.
365 *
366 * PRETHAW Quiesce as if for FREEZE; additionally, prepare for restoring
367 * the system from a snapshot taken after an earlier FREEZE.
368 * Some drivers will need to reset their hardware state instead
369 * of preserving it, to ensure that it's never mistaken for the
370 * state which that earlier snapshot had set up.
371 *
372 * A minimally power-aware driver treats all messages as SUSPEND, fully
373 * reinitializes its device during resume() -- whether or not it was reset
374 * during the suspend/resume cycle -- and can't issue wakeup events.
375 *
376 * More power-aware drivers may also use low power states at runtime as
377 * well as during system sleep states like PM_SUSPEND_STANDBY. They may
378 * be able to use wakeup events to exit from runtime low-power states,
379 * or from system low-power states such as standby or suspend-to-RAM.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 */
381
Rafael J. Wysocki296699d2007-07-29 23:27:18 +0200382#ifdef CONFIG_PM_SLEEP
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200383extern void device_pm_lock(void);
Rafael J. Wysocki770824b2009-02-22 18:38:50 +0100384extern int sysdev_resume(void);
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200385extern void device_power_up(pm_message_t state);
386extern void device_resume(pm_message_t state);
387
388extern void device_pm_unlock(void);
Rafael J. Wysocki770824b2009-02-22 18:38:50 +0100389extern int sysdev_suspend(pm_message_t state);
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200390extern int device_power_down(pm_message_t state);
Pavel Machek620b0322005-06-25 14:55:11 -0700391extern int device_suspend(pm_message_t state);
Linus Torvalds7c8265f2006-06-24 14:50:29 -0700392extern int device_prepare_suspend(pm_message_t state);
David Brownell0ac85242005-09-12 19:39:34 -0700393
Andrew Morton02669492006-03-23 01:38:34 -0800394extern void __suspend_report_result(const char *function, void *fn, int ret);
395
396#define suspend_report_result(fn, ret) \
397 do { \
Harvey Harrisond5c003b2008-10-15 22:01:24 -0700398 __suspend_report_result(__func__, fn, ret); \
Andrew Morton02669492006-03-23 01:38:34 -0800399 } while (0)
Andrew Morton9a7834d2005-10-23 23:02:20 -0700400
Alan Sternd288e472008-03-19 22:37:42 +0100401#else /* !CONFIG_PM_SLEEP */
402
Cornelia Huckffa6a702009-03-04 12:44:00 +0100403#define device_pm_lock() do {} while (0)
404#define device_pm_unlock() do {} while (0)
405
Alan Sternd288e472008-03-19 22:37:42 +0100406static inline int device_suspend(pm_message_t state)
407{
408 return 0;
409}
410
Alan Stern9a3df1f2008-03-19 22:39:13 +0100411#define suspend_report_result(fn, ret) do {} while (0)
Alan Sternd288e472008-03-19 22:37:42 +0100412
413#endif /* !CONFIG_PM_SLEEP */
414
Cornelia Huckffa6a702009-03-04 12:44:00 +0100415/* How to reorder dpm_list after device_move() */
416enum dpm_order {
417 DPM_ORDER_NONE,
418 DPM_ORDER_DEV_AFTER_PARENT,
419 DPM_ORDER_PARENT_BEFORE_DEV,
420 DPM_ORDER_DEV_LAST,
421};
422
Len Brown9f9adec2007-12-13 17:38:03 -0500423/*
424 * Global Power Management flags
425 * Used to keep APM and ACPI from both being active
426 */
427extern unsigned int pm_flags;
428
429#define PM_APM 1
430#define PM_ACPI 2
431
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432#endif /* _LINUX_PM_H */