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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/**
44 * struct pm_ops - device PM callbacks
45 *
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 *
129 * All of the above callbacks, except for @complete(), return error codes.
130 * However, the error codes returned by the resume operations, @resume(),
131 * @thaw(), and @restore(), do not cause the PM core to abort the resume
132 * transition during which they are returned. The error codes returned in
133 * that cases are only printed by the PM core to the system logs for debugging
134 * purposes. Still, it is recommended that drivers only return error codes
135 * from their resume methods in case of an unrecoverable failure (i.e. when the
136 * device being handled refuses to resume and becomes unusable) to allow us to
137 * modify the PM core in the future, so that it can avoid attempting to handle
138 * devices that failed to resume and their children.
139 *
140 * It is allowed to unregister devices while the above callbacks are being
141 * executed. However, it is not allowed to unregister a device from within any
142 * of its own callbacks.
143 */
144
145struct pm_ops {
146 int (*prepare)(struct device *dev);
147 void (*complete)(struct device *dev);
148 int (*suspend)(struct device *dev);
149 int (*resume)(struct device *dev);
150 int (*freeze)(struct device *dev);
151 int (*thaw)(struct device *dev);
152 int (*poweroff)(struct device *dev);
153 int (*restore)(struct device *dev);
154};
155
156/**
157 * struct pm_ext_ops - extended device PM callbacks
158 *
159 * Some devices require certain operations related to suspend and hibernation
160 * to be carried out with interrupts disabled. Thus, 'struct pm_ext_ops' below
161 * is defined, adding callbacks to be executed with interrupts disabled to
162 * 'struct pm_ops'.
163 *
164 * The following callbacks included in 'struct pm_ext_ops' are executed with
165 * the nonboot CPUs switched off and with interrupts disabled on the only
166 * functional CPU. They also are executed with the PM core list of devices
167 * locked, so they must NOT unregister any devices.
168 *
169 * @suspend_noirq: Complete the operations of ->suspend() by carrying out any
170 * actions required for suspending the device that need interrupts to be
171 * disabled
172 *
173 * @resume_noirq: Prepare for the execution of ->resume() by carrying out any
174 * actions required for resuming the device that need interrupts to be
175 * disabled
176 *
177 * @freeze_noirq: Complete the operations of ->freeze() by carrying out any
178 * actions required for freezing the device that need interrupts to be
179 * disabled
180 *
181 * @thaw_noirq: Prepare for the execution of ->thaw() by carrying out any
182 * actions required for thawing the device that need interrupts to be
183 * disabled
184 *
185 * @poweroff_noirq: Complete the operations of ->poweroff() by carrying out any
186 * actions required for handling the device that need interrupts to be
187 * disabled
188 *
189 * @restore_noirq: Prepare for the execution of ->restore() by carrying out any
190 * actions required for restoring the operations of the device that need
191 * interrupts to be disabled
192 *
193 * All of the above callbacks return error codes, but the error codes returned
194 * by the resume operations, @resume_noirq(), @thaw_noirq(), and
195 * @restore_noirq(), do not cause the PM core to abort the resume transition
196 * during which they are returned. The error codes returned in that cases are
197 * only printed by the PM core to the system logs for debugging purposes.
198 * Still, as stated above, it is recommended that drivers only return error
199 * codes from their resume methods if the device being handled fails to resume
200 * and is not usable any more.
201 */
202
203struct pm_ext_ops {
204 struct pm_ops base;
205 int (*suspend_noirq)(struct device *dev);
206 int (*resume_noirq)(struct device *dev);
207 int (*freeze_noirq)(struct device *dev);
208 int (*thaw_noirq)(struct device *dev);
209 int (*poweroff_noirq)(struct device *dev);
210 int (*restore_noirq)(struct device *dev);
211};
212
213/**
214 * PM_EVENT_ messages
215 *
216 * The following PM_EVENT_ messages are defined for the internal use of the PM
217 * core, in order to provide a mechanism allowing the high level suspend and
218 * hibernation code to convey the necessary information to the device PM core
219 * code:
220 *
221 * ON No transition.
222 *
223 * FREEZE System is going to hibernate, call ->prepare() and ->freeze()
224 * for all devices.
225 *
226 * SUSPEND System is going to suspend, call ->prepare() and ->suspend()
227 * for all devices.
228 *
229 * HIBERNATE Hibernation image has been saved, call ->prepare() and
230 * ->poweroff() for all devices.
231 *
232 * QUIESCE Contents of main memory are going to be restored from a (loaded)
233 * hibernation image, call ->prepare() and ->freeze() for all
234 * devices.
235 *
236 * RESUME System is resuming, call ->resume() and ->complete() for all
237 * devices.
238 *
239 * THAW Hibernation image has been created, call ->thaw() and
240 * ->complete() for all devices.
241 *
242 * RESTORE Contents of main memory have been restored from a hibernation
243 * image, call ->restore() and ->complete() for all devices.
244 *
245 * RECOVER Creation of a hibernation image or restoration of the main
246 * memory contents from a hibernation image has failed, call
247 * ->thaw() and ->complete() for all devices.
Alan Stern8111d1b2008-07-23 21:28:37 -0700248 *
249 * The following PM_EVENT_ messages are defined for internal use by
250 * kernel subsystems. They are never issued by the PM core.
251 *
252 * USER_SUSPEND Manual selective suspend was issued by userspace.
253 *
254 * USER_RESUME Manual selective resume was issued by userspace.
255 *
256 * REMOTE_WAKEUP Remote-wakeup request was received from the device.
257 *
258 * AUTO_SUSPEND Automatic (device idle) runtime suspend was
259 * initiated by the subsystem.
260 *
261 * AUTO_RESUME Automatic (device needed) runtime resume was
262 * requested by a driver.
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200263 */
264
265#define PM_EVENT_ON 0x0000
266#define PM_EVENT_FREEZE 0x0001
267#define PM_EVENT_SUSPEND 0x0002
268#define PM_EVENT_HIBERNATE 0x0004
269#define PM_EVENT_QUIESCE 0x0008
270#define PM_EVENT_RESUME 0x0010
271#define PM_EVENT_THAW 0x0020
272#define PM_EVENT_RESTORE 0x0040
273#define PM_EVENT_RECOVER 0x0080
Alan Stern8111d1b2008-07-23 21:28:37 -0700274#define PM_EVENT_USER 0x0100
275#define PM_EVENT_REMOTE 0x0200
276#define PM_EVENT_AUTO 0x0400
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200277
Alan Stern8111d1b2008-07-23 21:28:37 -0700278#define PM_EVENT_SLEEP (PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
279#define PM_EVENT_USER_SUSPEND (PM_EVENT_USER | PM_EVENT_SUSPEND)
280#define PM_EVENT_USER_RESUME (PM_EVENT_USER | PM_EVENT_RESUME)
281#define PM_EVENT_REMOTE_WAKEUP (PM_EVENT_REMOTE | PM_EVENT_RESUME)
282#define PM_EVENT_AUTO_SUSPEND (PM_EVENT_AUTO | PM_EVENT_SUSPEND)
283#define PM_EVENT_AUTO_RESUME (PM_EVENT_AUTO | PM_EVENT_RESUME)
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200284
Alan Stern8111d1b2008-07-23 21:28:37 -0700285#define PMSG_ON ((struct pm_message){ .event = PM_EVENT_ON, })
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200286#define PMSG_FREEZE ((struct pm_message){ .event = PM_EVENT_FREEZE, })
287#define PMSG_QUIESCE ((struct pm_message){ .event = PM_EVENT_QUIESCE, })
288#define PMSG_SUSPEND ((struct pm_message){ .event = PM_EVENT_SUSPEND, })
289#define PMSG_HIBERNATE ((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
290#define PMSG_RESUME ((struct pm_message){ .event = PM_EVENT_RESUME, })
291#define PMSG_THAW ((struct pm_message){ .event = PM_EVENT_THAW, })
292#define PMSG_RESTORE ((struct pm_message){ .event = PM_EVENT_RESTORE, })
293#define PMSG_RECOVER ((struct pm_message){ .event = PM_EVENT_RECOVER, })
Alan Stern8111d1b2008-07-23 21:28:37 -0700294#define PMSG_USER_SUSPEND ((struct pm_messge) \
295 { .event = PM_EVENT_USER_SUSPEND, })
296#define PMSG_USER_RESUME ((struct pm_messge) \
297 { .event = PM_EVENT_USER_RESUME, })
298#define PMSG_REMOTE_RESUME ((struct pm_messge) \
299 { .event = PM_EVENT_REMOTE_RESUME, })
300#define PMSG_AUTO_SUSPEND ((struct pm_messge) \
301 { .event = PM_EVENT_AUTO_SUSPEND, })
302#define PMSG_AUTO_RESUME ((struct pm_messge) \
303 { .event = PM_EVENT_AUTO_RESUME, })
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200304
305/**
306 * Device power management states
307 *
308 * These state labels are used internally by the PM core to indicate the current
309 * status of a device with respect to the PM core operations.
310 *
311 * DPM_ON Device is regarded as operational. Set this way
312 * initially and when ->complete() is about to be called.
313 * Also set when ->prepare() fails.
314 *
315 * DPM_PREPARING Device is going to be prepared for a PM transition. Set
316 * when ->prepare() is about to be called.
317 *
318 * DPM_RESUMING Device is going to be resumed. Set when ->resume(),
319 * ->thaw(), or ->restore() is about to be called.
320 *
321 * DPM_SUSPENDING Device has been prepared for a power transition. Set
322 * when ->prepare() has just succeeded.
323 *
324 * DPM_OFF Device is regarded as inactive. Set immediately after
325 * ->suspend(), ->freeze(), or ->poweroff() has succeeded.
326 * Also set when ->resume()_noirq, ->thaw_noirq(), or
327 * ->restore_noirq() is about to be called.
328 *
329 * DPM_OFF_IRQ Device is in a "deep sleep". Set immediately after
330 * ->suspend_noirq(), ->freeze_noirq(), or
331 * ->poweroff_noirq() has just succeeded.
332 */
333
334enum dpm_state {
335 DPM_INVALID,
336 DPM_ON,
337 DPM_PREPARING,
338 DPM_RESUMING,
339 DPM_SUSPENDING,
340 DPM_OFF,
341 DPM_OFF_IRQ,
342};
343
344struct dev_pm_info {
345 pm_message_t power_state;
346 unsigned can_wakeup:1;
347 unsigned should_wakeup:1;
348 enum dpm_state status; /* Owned by the PM core */
349#ifdef CONFIG_PM_SLEEP
350 struct list_head entry;
351#endif
352};
353
354/*
355 * The PM_EVENT_ messages are also used by drivers implementing the legacy
356 * suspend framework, based on the ->suspend() and ->resume() callbacks common
357 * for suspend and hibernation transitions, according to the rules below.
358 */
359
360/* Necessary, because several drivers use PM_EVENT_PRETHAW */
361#define PM_EVENT_PRETHAW PM_EVENT_QUIESCE
362
363/*
David Brownell82bb67f2006-08-14 23:11:04 -0700364 * One transition is triggered by resume(), after a suspend() call; the
365 * message is implicit:
366 *
367 * ON Driver starts working again, responding to hardware events
368 * and software requests. The hardware may have gone through
369 * a power-off reset, or it may have maintained state from the
370 * previous suspend() which the driver will rely on while
371 * resuming. On most platforms, there are no restrictions on
372 * availability of resources like clocks during resume().
373 *
374 * Other transitions are triggered by messages sent using suspend(). All
375 * these transitions quiesce the driver, so that I/O queues are inactive.
376 * That commonly entails turning off IRQs and DMA; there may be rules
377 * about how to quiesce that are specific to the bus or the device's type.
378 * (For example, network drivers mark the link state.) Other details may
379 * differ according to the message:
380 *
381 * SUSPEND Quiesce, enter a low power device state appropriate for
382 * the upcoming system state (such as PCI_D3hot), and enable
383 * wakeup events as appropriate.
384 *
Rafael J. Wysocki3a2d5b72008-02-23 19:13:25 +0100385 * HIBERNATE Enter a low power device state appropriate for the hibernation
386 * state (eg. ACPI S4) and enable wakeup events as appropriate.
387 *
David Brownell82bb67f2006-08-14 23:11:04 -0700388 * FREEZE Quiesce operations so that a consistent image can be saved;
389 * but do NOT otherwise enter a low power device state, and do
390 * NOT emit system wakeup events.
391 *
392 * PRETHAW Quiesce as if for FREEZE; additionally, prepare for restoring
393 * the system from a snapshot taken after an earlier FREEZE.
394 * Some drivers will need to reset their hardware state instead
395 * of preserving it, to ensure that it's never mistaken for the
396 * state which that earlier snapshot had set up.
397 *
398 * A minimally power-aware driver treats all messages as SUSPEND, fully
399 * reinitializes its device during resume() -- whether or not it was reset
400 * during the suspend/resume cycle -- and can't issue wakeup events.
401 *
402 * More power-aware drivers may also use low power states at runtime as
403 * well as during system sleep states like PM_SUSPEND_STANDBY. They may
404 * be able to use wakeup events to exit from runtime low-power states,
405 * or from system low-power states such as standby or suspend-to-RAM.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 */
407
Rafael J. Wysocki296699d2007-07-29 23:27:18 +0200408#ifdef CONFIG_PM_SLEEP
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200409extern void device_pm_lock(void);
410extern void device_power_up(pm_message_t state);
411extern void device_resume(pm_message_t state);
412
413extern void device_pm_unlock(void);
414extern int device_power_down(pm_message_t state);
Pavel Machek620b0322005-06-25 14:55:11 -0700415extern int device_suspend(pm_message_t state);
Linus Torvalds7c8265f2006-06-24 14:50:29 -0700416extern int device_prepare_suspend(pm_message_t state);
David Brownell0ac85242005-09-12 19:39:34 -0700417
Andrew Morton02669492006-03-23 01:38:34 -0800418extern void __suspend_report_result(const char *function, void *fn, int ret);
419
420#define suspend_report_result(fn, ret) \
421 do { \
Harvey Harrisond5c003b2008-10-15 22:01:24 -0700422 __suspend_report_result(__func__, fn, ret); \
Andrew Morton02669492006-03-23 01:38:34 -0800423 } while (0)
Andrew Morton9a7834d2005-10-23 23:02:20 -0700424
Alan Sternd288e472008-03-19 22:37:42 +0100425#else /* !CONFIG_PM_SLEEP */
426
427static inline int device_suspend(pm_message_t state)
428{
429 return 0;
430}
431
Alan Stern9a3df1f2008-03-19 22:39:13 +0100432#define suspend_report_result(fn, ret) do {} while (0)
Alan Sternd288e472008-03-19 22:37:42 +0100433
434#endif /* !CONFIG_PM_SLEEP */
435
Len Brown9f9adec2007-12-13 17:38:03 -0500436/*
437 * Global Power Management flags
438 * Used to keep APM and ACPI from both being active
439 */
440extern unsigned int pm_flags;
441
442#define PM_APM 1
443#define PM_ACPI 2
444
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445#endif /* _LINUX_PM_H */