1 /*
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
24 #include <linux/list.h>
25
26 /*
27 * Callbacks for platform drivers to implement.
28 */
29 extern void (*pm_idle)(void);
30 extern void (*pm_power_off)(void);
31 extern void (*pm_power_off_prepare)(void);
32
33 /*
34 * Device power management
35 */
36
37 struct device;
38
39 typedef struct pm_message {
40 int event;
41 } pm_message_t;
42
43 /**
44 * struct dev_pm_ops - device PM callbacks
45 *
46 * 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).
52 *
53 * 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 * @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 *
153 * 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.
168 */
169
170 struct 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);
179 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.
222 *
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.
237 */
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
248 #define PM_EVENT_USER 0x0100
249 #define PM_EVENT_REMOTE 0x0200
250 #define PM_EVENT_AUTO 0x0400
251
252 #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)
255 #define PM_EVENT_REMOTE_RESUME (PM_EVENT_REMOTE | PM_EVENT_RESUME)
256 #define PM_EVENT_AUTO_SUSPEND (PM_EVENT_AUTO | PM_EVENT_SUSPEND)
257 #define PM_EVENT_AUTO_RESUME (PM_EVENT_AUTO | PM_EVENT_RESUME)
258
259 #define PMSG_ON ((struct pm_message){ .event = PM_EVENT_ON, })
260 #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, })
268 #define PMSG_USER_SUSPEND ((struct pm_message) \
269 { .event = PM_EVENT_USER_SUSPEND, })
270 #define PMSG_USER_RESUME ((struct pm_message) \
271 { .event = PM_EVENT_USER_RESUME, })
272 #define PMSG_REMOTE_RESUME ((struct pm_message) \
273 { .event = PM_EVENT_REMOTE_RESUME, })
274 #define PMSG_AUTO_SUSPEND ((struct pm_message) \
275 { .event = PM_EVENT_AUTO_SUSPEND, })
276 #define PMSG_AUTO_RESUME ((struct pm_message) \
277 { .event = PM_EVENT_AUTO_RESUME, })
278
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
308 enum 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
318 struct 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 /*
338 * 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 *
359 * HIBERNATE Enter a low power device state appropriate for the hibernation
360 * state (eg. ACPI S4) and enable wakeup events as appropriate.
361 *
362 * 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.
380 */
381
382 #ifdef CONFIG_PM_SLEEP
383 extern void device_pm_lock(void);
384 extern int sysdev_resume(void);
385 extern void device_power_up(pm_message_t state);
386 extern void device_resume(pm_message_t state);
387
388 extern void device_pm_unlock(void);
389 extern int sysdev_suspend(pm_message_t state);
390 extern int device_power_down(pm_message_t state);
391 extern int device_suspend(pm_message_t state);
392 extern int device_prepare_suspend(pm_message_t state);
393
394 extern void __suspend_report_result(const char *function, void *fn, int ret);
395
396 #define suspend_report_result(fn, ret) \
397 do { \
398 __suspend_report_result(__func__, fn, ret); \
399 } while (0)
400
401 #else /* !CONFIG_PM_SLEEP */
402
device_suspend(pm_message_t state)403 static inline int device_suspend(pm_message_t state)
404 {
405 return 0;
406 }
407
408 #define suspend_report_result(fn, ret) do {} while (0)
409
410 #endif /* !CONFIG_PM_SLEEP */
411
412 /*
413 * Global Power Management flags
414 * Used to keep APM and ACPI from both being active
415 */
416 extern unsigned int pm_flags;
417
418 #define PM_APM 1
419 #define PM_ACPI 2
420
421 #endif /* _LINUX_PM_H */
422