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 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 * 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 */ 144 145 struct 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 */ 202 203 struct 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. 248 * 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. 263 */ 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 274 #define PM_EVENT_USER 0x0100 275 #define PM_EVENT_REMOTE 0x0200 276 #define PM_EVENT_AUTO 0x0400 277 278 #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) 284 285 #define PMSG_ON ((struct pm_message){ .event = PM_EVENT_ON, }) 286 #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, }) 294 #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, }) 304 305 /** 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 */ 333 334 enum 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 }; 343 344 struct 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 /* 364 * 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 * 385 * HIBERNATE Enter a low power device state appropriate for the hibernation 386 * state (eg. ACPI S4) and enable wakeup events as appropriate. 387 * 388 * 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. 406 */ 407 408 #ifdef CONFIG_PM_SLEEP 409 extern void device_pm_lock(void); 410 extern void device_power_up(pm_message_t state); 411 extern void device_resume(pm_message_t state); 412 413 extern void device_pm_unlock(void); 414 extern int device_power_down(pm_message_t state); 415 extern int device_suspend(pm_message_t state); 416 extern int device_prepare_suspend(pm_message_t state); 417 418 extern void __suspend_report_result(const char *function, void *fn, int ret); 419 420 #define suspend_report_result(fn, ret) \ 421 do { \ 422 __suspend_report_result(__FUNCTION__, fn, ret); \ 423 } while (0) 424 425 #else /* !CONFIG_PM_SLEEP */ 426 427 static inline int device_suspend(pm_message_t state) 428 { 429 return 0; 430 } 431 432 #define suspend_report_result(fn, ret) do {} while (0) 433 434 #endif /* !CONFIG_PM_SLEEP */ 435 436 /* 437 * Global Power Management flags 438 * Used to keep APM and ACPI from both being active 439 */ 440 extern unsigned int pm_flags; 441 442 #define PM_APM 1 443 #define PM_ACPI 2 444 445 #endif /* _LINUX_PM_H */ 446