| 1 | /* |
| 2 | * kernel/power/main.c - PM subsystem core functionality. |
| 3 | * |
| 4 | * Copyright (c) 2003 Patrick Mochel |
| 5 | * Copyright (c) 2003 Open Source Development Lab |
| 6 | * |
| 7 | * This file is released under the GPLv2 |
| 8 | * |
| 9 | */ |
| 10 | |
| 11 | #include <linux/module.h> |
| 12 | #include <linux/suspend.h> |
| 13 | #include <linux/kobject.h> |
| 14 | #include <linux/string.h> |
| 15 | #include <linux/delay.h> |
| 16 | #include <linux/errno.h> |
| 17 | #include <linux/kmod.h> |
| 18 | #include <linux/init.h> |
| 19 | #include <linux/console.h> |
| 20 | #include <linux/cpu.h> |
| 21 | #include <linux/resume-trace.h> |
| 22 | #include <linux/freezer.h> |
| 23 | #include <linux/vmstat.h> |
| 24 | #include <linux/syscalls.h> |
| 25 | |
| 26 | #include "power.h" |
| 27 | |
| 28 | DEFINE_MUTEX(pm_mutex); |
| 29 | |
| 30 | unsigned int pm_flags; |
| 31 | EXPORT_SYMBOL(pm_flags); |
| 32 | |
| 33 | #ifdef CONFIG_PM_SLEEP |
| 34 | |
| 35 | /* Routines for PM-transition notifications */ |
| 36 | |
| 37 | static BLOCKING_NOTIFIER_HEAD(pm_chain_head); |
| 38 | |
| 39 | int register_pm_notifier(struct notifier_block *nb) |
| 40 | { |
| 41 | return blocking_notifier_chain_register(&pm_chain_head, nb); |
| 42 | } |
| 43 | EXPORT_SYMBOL_GPL(register_pm_notifier); |
| 44 | |
| 45 | int unregister_pm_notifier(struct notifier_block *nb) |
| 46 | { |
| 47 | return blocking_notifier_chain_unregister(&pm_chain_head, nb); |
| 48 | } |
| 49 | EXPORT_SYMBOL_GPL(unregister_pm_notifier); |
| 50 | |
| 51 | int pm_notifier_call_chain(unsigned long val) |
| 52 | { |
| 53 | return (blocking_notifier_call_chain(&pm_chain_head, val, NULL) |
| 54 | == NOTIFY_BAD) ? -EINVAL : 0; |
| 55 | } |
| 56 | |
| 57 | #ifdef CONFIG_PM_DEBUG |
| 58 | int pm_test_level = TEST_NONE; |
| 59 | |
| 60 | static const char * const pm_tests[__TEST_AFTER_LAST] = { |
| 61 | [TEST_NONE] = "none", |
| 62 | [TEST_CORE] = "core", |
| 63 | [TEST_CPUS] = "processors", |
| 64 | [TEST_PLATFORM] = "platform", |
| 65 | [TEST_DEVICES] = "devices", |
| 66 | [TEST_FREEZER] = "freezer", |
| 67 | }; |
| 68 | |
| 69 | static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr, |
| 70 | char *buf) |
| 71 | { |
| 72 | char *s = buf; |
| 73 | int level; |
| 74 | |
| 75 | for (level = TEST_FIRST; level <= TEST_MAX; level++) |
| 76 | if (pm_tests[level]) { |
| 77 | if (level == pm_test_level) |
| 78 | s += sprintf(s, "[%s] ", pm_tests[level]); |
| 79 | else |
| 80 | s += sprintf(s, "%s ", pm_tests[level]); |
| 81 | } |
| 82 | |
| 83 | if (s != buf) |
| 84 | /* convert the last space to a newline */ |
| 85 | *(s-1) = '\n'; |
| 86 | |
| 87 | return (s - buf); |
| 88 | } |
| 89 | |
| 90 | static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr, |
| 91 | const char *buf, size_t n) |
| 92 | { |
| 93 | const char * const *s; |
| 94 | int level; |
| 95 | char *p; |
| 96 | int len; |
| 97 | int error = -EINVAL; |
| 98 | |
| 99 | p = memchr(buf, '\n', n); |
| 100 | len = p ? p - buf : n; |
| 101 | |
| 102 | mutex_lock(&pm_mutex); |
| 103 | |
| 104 | level = TEST_FIRST; |
| 105 | for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++) |
| 106 | if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) { |
| 107 | pm_test_level = level; |
| 108 | error = 0; |
| 109 | break; |
| 110 | } |
| 111 | |
| 112 | mutex_unlock(&pm_mutex); |
| 113 | |
| 114 | return error ? error : n; |
| 115 | } |
| 116 | |
| 117 | power_attr(pm_test); |
| 118 | #endif /* CONFIG_PM_DEBUG */ |
| 119 | |
| 120 | #endif /* CONFIG_PM_SLEEP */ |
| 121 | |
| 122 | #ifdef CONFIG_SUSPEND |
| 123 | |
| 124 | static int suspend_test(int level) |
| 125 | { |
| 126 | #ifdef CONFIG_PM_DEBUG |
| 127 | if (pm_test_level == level) { |
| 128 | printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n"); |
| 129 | mdelay(5000); |
| 130 | return 1; |
| 131 | } |
| 132 | #endif /* !CONFIG_PM_DEBUG */ |
| 133 | return 0; |
| 134 | } |
| 135 | |
| 136 | #ifdef CONFIG_PM_TEST_SUSPEND |
| 137 | |
| 138 | /* |
| 139 | * We test the system suspend code by setting an RTC wakealarm a short |
| 140 | * time in the future, then suspending. Suspending the devices won't |
| 141 | * normally take long ... some systems only need a few milliseconds. |
| 142 | * |
| 143 | * The time it takes is system-specific though, so when we test this |
| 144 | * during system bootup we allow a LOT of time. |
| 145 | */ |
| 146 | #define TEST_SUSPEND_SECONDS 5 |
| 147 | |
| 148 | static unsigned long suspend_test_start_time; |
| 149 | |
| 150 | static void suspend_test_start(void) |
| 151 | { |
| 152 | /* FIXME Use better timebase than "jiffies", ideally a clocksource. |
| 153 | * What we want is a hardware counter that will work correctly even |
| 154 | * during the irqs-are-off stages of the suspend/resume cycle... |
| 155 | */ |
| 156 | suspend_test_start_time = jiffies; |
| 157 | } |
| 158 | |
| 159 | static void suspend_test_finish(const char *label) |
| 160 | { |
| 161 | long nj = jiffies - suspend_test_start_time; |
| 162 | unsigned msec; |
| 163 | |
| 164 | msec = jiffies_to_msecs(abs(nj)); |
| 165 | pr_info("PM: %s took %d.%03d seconds\n", label, |
| 166 | msec / 1000, msec % 1000); |
| 167 | |
| 168 | /* Warning on suspend means the RTC alarm period needs to be |
| 169 | * larger -- the system was sooo slooowwww to suspend that the |
| 170 | * alarm (should have) fired before the system went to sleep! |
| 171 | * |
| 172 | * Warning on either suspend or resume also means the system |
| 173 | * has some performance issues. The stack dump of a WARN_ON |
| 174 | * is more likely to get the right attention than a printk... |
| 175 | */ |
| 176 | WARN(msec > (TEST_SUSPEND_SECONDS * 1000), "Component: %s\n", label); |
| 177 | } |
| 178 | |
| 179 | #else |
| 180 | |
| 181 | static void suspend_test_start(void) |
| 182 | { |
| 183 | } |
| 184 | |
| 185 | static void suspend_test_finish(const char *label) |
| 186 | { |
| 187 | } |
| 188 | |
| 189 | #endif |
| 190 | |
| 191 | /* This is just an arbitrary number */ |
| 192 | #define FREE_PAGE_NUMBER (100) |
| 193 | |
| 194 | static struct platform_suspend_ops *suspend_ops; |
| 195 | |
| 196 | /** |
| 197 | * suspend_set_ops - Set the global suspend method table. |
| 198 | * @ops: Pointer to ops structure. |
| 199 | */ |
| 200 | |
| 201 | void suspend_set_ops(struct platform_suspend_ops *ops) |
| 202 | { |
| 203 | mutex_lock(&pm_mutex); |
| 204 | suspend_ops = ops; |
| 205 | mutex_unlock(&pm_mutex); |
| 206 | } |
| 207 | |
| 208 | /** |
| 209 | * suspend_valid_only_mem - generic memory-only valid callback |
| 210 | * |
| 211 | * Platform drivers that implement mem suspend only and only need |
| 212 | * to check for that in their .valid callback can use this instead |
| 213 | * of rolling their own .valid callback. |
| 214 | */ |
| 215 | int suspend_valid_only_mem(suspend_state_t state) |
| 216 | { |
| 217 | return state == PM_SUSPEND_MEM; |
| 218 | } |
| 219 | |
| 220 | /** |
| 221 | * suspend_prepare - Do prep work before entering low-power state. |
| 222 | * |
| 223 | * This is common code that is called for each state that we're entering. |
| 224 | * Run suspend notifiers, allocate a console and stop all processes. |
| 225 | */ |
| 226 | static int suspend_prepare(void) |
| 227 | { |
| 228 | int error; |
| 229 | unsigned int free_pages; |
| 230 | |
| 231 | if (!suspend_ops || !suspend_ops->enter) |
| 232 | return -EPERM; |
| 233 | |
| 234 | pm_prepare_console(); |
| 235 | |
| 236 | error = pm_notifier_call_chain(PM_SUSPEND_PREPARE); |
| 237 | if (error) |
| 238 | goto Finish; |
| 239 | |
| 240 | error = usermodehelper_disable(); |
| 241 | if (error) |
| 242 | goto Finish; |
| 243 | |
| 244 | if (suspend_freeze_processes()) { |
| 245 | error = -EAGAIN; |
| 246 | goto Thaw; |
| 247 | } |
| 248 | |
| 249 | free_pages = global_page_state(NR_FREE_PAGES); |
| 250 | if (free_pages < FREE_PAGE_NUMBER) { |
| 251 | pr_debug("PM: free some memory\n"); |
| 252 | shrink_all_memory(FREE_PAGE_NUMBER - free_pages); |
| 253 | if (nr_free_pages() < FREE_PAGE_NUMBER) { |
| 254 | error = -ENOMEM; |
| 255 | printk(KERN_ERR "PM: No enough memory\n"); |
| 256 | } |
| 257 | } |
| 258 | if (!error) |
| 259 | return 0; |
| 260 | |
| 261 | Thaw: |
| 262 | suspend_thaw_processes(); |
| 263 | usermodehelper_enable(); |
| 264 | Finish: |
| 265 | pm_notifier_call_chain(PM_POST_SUSPEND); |
| 266 | pm_restore_console(); |
| 267 | return error; |
| 268 | } |
| 269 | |
| 270 | /* default implementation */ |
| 271 | void __attribute__ ((weak)) arch_suspend_disable_irqs(void) |
| 272 | { |
| 273 | local_irq_disable(); |
| 274 | } |
| 275 | |
| 276 | /* default implementation */ |
| 277 | void __attribute__ ((weak)) arch_suspend_enable_irqs(void) |
| 278 | { |
| 279 | local_irq_enable(); |
| 280 | } |
| 281 | |
| 282 | /** |
| 283 | * suspend_enter - enter the desired system sleep state. |
| 284 | * @state: state to enter |
| 285 | * |
| 286 | * This function should be called after devices have been suspended. |
| 287 | */ |
| 288 | static int suspend_enter(suspend_state_t state) |
| 289 | { |
| 290 | int error; |
| 291 | |
| 292 | if (suspend_ops->prepare) { |
| 293 | error = suspend_ops->prepare(); |
| 294 | if (error) |
| 295 | return error; |
| 296 | } |
| 297 | |
| 298 | error = device_power_down(PMSG_SUSPEND); |
| 299 | if (error) { |
| 300 | printk(KERN_ERR "PM: Some devices failed to power down\n"); |
| 301 | goto Platfrom_finish; |
| 302 | } |
| 303 | |
| 304 | if (suspend_ops->prepare_late) { |
| 305 | error = suspend_ops->prepare_late(); |
| 306 | if (error) |
| 307 | goto Power_up_devices; |
| 308 | } |
| 309 | |
| 310 | if (suspend_test(TEST_PLATFORM)) |
| 311 | goto Platform_wake; |
| 312 | |
| 313 | error = disable_nonboot_cpus(); |
| 314 | if (error || suspend_test(TEST_CPUS)) |
| 315 | goto Enable_cpus; |
| 316 | |
| 317 | arch_suspend_disable_irqs(); |
| 318 | BUG_ON(!irqs_disabled()); |
| 319 | |
| 320 | error = sysdev_suspend(PMSG_SUSPEND); |
| 321 | if (!error) { |
| 322 | if (!suspend_test(TEST_CORE)) |
| 323 | error = suspend_ops->enter(state); |
| 324 | sysdev_resume(); |
| 325 | } |
| 326 | |
| 327 | arch_suspend_enable_irqs(); |
| 328 | BUG_ON(irqs_disabled()); |
| 329 | |
| 330 | Enable_cpus: |
| 331 | enable_nonboot_cpus(); |
| 332 | |
| 333 | Platform_wake: |
| 334 | if (suspend_ops->wake) |
| 335 | suspend_ops->wake(); |
| 336 | |
| 337 | Power_up_devices: |
| 338 | device_power_up(PMSG_RESUME); |
| 339 | |
| 340 | Platfrom_finish: |
| 341 | if (suspend_ops->finish) |
| 342 | suspend_ops->finish(); |
| 343 | |
| 344 | return error; |
| 345 | } |
| 346 | |
| 347 | /** |
| 348 | * suspend_devices_and_enter - suspend devices and enter the desired system |
| 349 | * sleep state. |
| 350 | * @state: state to enter |
| 351 | */ |
| 352 | int suspend_devices_and_enter(suspend_state_t state) |
| 353 | { |
| 354 | int error; |
| 355 | |
| 356 | if (!suspend_ops) |
| 357 | return -ENOSYS; |
| 358 | |
| 359 | if (suspend_ops->begin) { |
| 360 | error = suspend_ops->begin(state); |
| 361 | if (error) |
| 362 | goto Close; |
| 363 | } |
| 364 | suspend_console(); |
| 365 | suspend_test_start(); |
| 366 | error = device_suspend(PMSG_SUSPEND); |
| 367 | if (error) { |
| 368 | printk(KERN_ERR "PM: Some devices failed to suspend\n"); |
| 369 | goto Recover_platform; |
| 370 | } |
| 371 | suspend_test_finish("suspend devices"); |
| 372 | if (suspend_test(TEST_DEVICES)) |
| 373 | goto Recover_platform; |
| 374 | |
| 375 | suspend_enter(state); |
| 376 | |
| 377 | Resume_devices: |
| 378 | suspend_test_start(); |
| 379 | device_resume(PMSG_RESUME); |
| 380 | suspend_test_finish("resume devices"); |
| 381 | resume_console(); |
| 382 | Close: |
| 383 | if (suspend_ops->end) |
| 384 | suspend_ops->end(); |
| 385 | return error; |
| 386 | |
| 387 | Recover_platform: |
| 388 | if (suspend_ops->recover) |
| 389 | suspend_ops->recover(); |
| 390 | goto Resume_devices; |
| 391 | } |
| 392 | |
| 393 | /** |
| 394 | * suspend_finish - Do final work before exiting suspend sequence. |
| 395 | * |
| 396 | * Call platform code to clean up, restart processes, and free the |
| 397 | * console that we've allocated. This is not called for suspend-to-disk. |
| 398 | */ |
| 399 | static void suspend_finish(void) |
| 400 | { |
| 401 | suspend_thaw_processes(); |
| 402 | usermodehelper_enable(); |
| 403 | pm_notifier_call_chain(PM_POST_SUSPEND); |
| 404 | pm_restore_console(); |
| 405 | } |
| 406 | |
| 407 | |
| 408 | |
| 409 | |
| 410 | static const char * const pm_states[PM_SUSPEND_MAX] = { |
| 411 | [PM_SUSPEND_STANDBY] = "standby", |
| 412 | [PM_SUSPEND_MEM] = "mem", |
| 413 | }; |
| 414 | |
| 415 | static inline int valid_state(suspend_state_t state) |
| 416 | { |
| 417 | /* All states need lowlevel support and need to be valid |
| 418 | * to the lowlevel implementation, no valid callback |
| 419 | * implies that none are valid. */ |
| 420 | if (!suspend_ops || !suspend_ops->valid || !suspend_ops->valid(state)) |
| 421 | return 0; |
| 422 | return 1; |
| 423 | } |
| 424 | |
| 425 | |
| 426 | /** |
| 427 | * enter_state - Do common work of entering low-power state. |
| 428 | * @state: pm_state structure for state we're entering. |
| 429 | * |
| 430 | * Make sure we're the only ones trying to enter a sleep state. Fail |
| 431 | * if someone has beat us to it, since we don't want anything weird to |
| 432 | * happen when we wake up. |
| 433 | * Then, do the setup for suspend, enter the state, and cleaup (after |
| 434 | * we've woken up). |
| 435 | */ |
| 436 | static int enter_state(suspend_state_t state) |
| 437 | { |
| 438 | int error; |
| 439 | |
| 440 | if (!valid_state(state)) |
| 441 | return -ENODEV; |
| 442 | |
| 443 | if (!mutex_trylock(&pm_mutex)) |
| 444 | return -EBUSY; |
| 445 | |
| 446 | printk(KERN_INFO "PM: Syncing filesystems ... "); |
| 447 | sys_sync(); |
| 448 | printk("done.\n"); |
| 449 | |
| 450 | pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]); |
| 451 | error = suspend_prepare(); |
| 452 | if (error) |
| 453 | goto Unlock; |
| 454 | |
| 455 | if (suspend_test(TEST_FREEZER)) |
| 456 | goto Finish; |
| 457 | |
| 458 | pr_debug("PM: Entering %s sleep\n", pm_states[state]); |
| 459 | error = suspend_devices_and_enter(state); |
| 460 | |
| 461 | Finish: |
| 462 | pr_debug("PM: Finishing wakeup.\n"); |
| 463 | suspend_finish(); |
| 464 | Unlock: |
| 465 | mutex_unlock(&pm_mutex); |
| 466 | return error; |
| 467 | } |
| 468 | |
| 469 | |
| 470 | /** |
| 471 | * pm_suspend - Externally visible function for suspending system. |
| 472 | * @state: Enumerated value of state to enter. |
| 473 | * |
| 474 | * Determine whether or not value is within range, get state |
| 475 | * structure, and enter (above). |
| 476 | */ |
| 477 | |
| 478 | int pm_suspend(suspend_state_t state) |
| 479 | { |
| 480 | if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX) |
| 481 | return enter_state(state); |
| 482 | return -EINVAL; |
| 483 | } |
| 484 | |
| 485 | EXPORT_SYMBOL(pm_suspend); |
| 486 | |
| 487 | #endif /* CONFIG_SUSPEND */ |
| 488 | |
| 489 | struct kobject *power_kobj; |
| 490 | |
| 491 | /** |
| 492 | * state - control system power state. |
| 493 | * |
| 494 | * show() returns what states are supported, which is hard-coded to |
| 495 | * 'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and |
| 496 | * 'disk' (Suspend-to-Disk). |
| 497 | * |
| 498 | * store() accepts one of those strings, translates it into the |
| 499 | * proper enumerated value, and initiates a suspend transition. |
| 500 | */ |
| 501 | |
| 502 | static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr, |
| 503 | char *buf) |
| 504 | { |
| 505 | char *s = buf; |
| 506 | #ifdef CONFIG_SUSPEND |
| 507 | int i; |
| 508 | |
| 509 | for (i = 0; i < PM_SUSPEND_MAX; i++) { |
| 510 | if (pm_states[i] && valid_state(i)) |
| 511 | s += sprintf(s,"%s ", pm_states[i]); |
| 512 | } |
| 513 | #endif |
| 514 | #ifdef CONFIG_HIBERNATION |
| 515 | s += sprintf(s, "%s\n", "disk"); |
| 516 | #else |
| 517 | if (s != buf) |
| 518 | /* convert the last space to a newline */ |
| 519 | *(s-1) = '\n'; |
| 520 | #endif |
| 521 | return (s - buf); |
| 522 | } |
| 523 | |
| 524 | static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr, |
| 525 | const char *buf, size_t n) |
| 526 | { |
| 527 | #ifdef CONFIG_SUSPEND |
| 528 | suspend_state_t state = PM_SUSPEND_STANDBY; |
| 529 | const char * const *s; |
| 530 | #endif |
| 531 | char *p; |
| 532 | int len; |
| 533 | int error = -EINVAL; |
| 534 | |
| 535 | p = memchr(buf, '\n', n); |
| 536 | len = p ? p - buf : n; |
| 537 | |
| 538 | /* First, check if we are requested to hibernate */ |
| 539 | if (len == 4 && !strncmp(buf, "disk", len)) { |
| 540 | error = hibernate(); |
| 541 | goto Exit; |
| 542 | } |
| 543 | |
| 544 | #ifdef CONFIG_SUSPEND |
| 545 | for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) { |
| 546 | if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) |
| 547 | break; |
| 548 | } |
| 549 | if (state < PM_SUSPEND_MAX && *s) |
| 550 | error = enter_state(state); |
| 551 | #endif |
| 552 | |
| 553 | Exit: |
| 554 | return error ? error : n; |
| 555 | } |
| 556 | |
| 557 | power_attr(state); |
| 558 | |
| 559 | #ifdef CONFIG_PM_TRACE |
| 560 | int pm_trace_enabled; |
| 561 | |
| 562 | static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr, |
| 563 | char *buf) |
| 564 | { |
| 565 | return sprintf(buf, "%d\n", pm_trace_enabled); |
| 566 | } |
| 567 | |
| 568 | static ssize_t |
| 569 | pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr, |
| 570 | const char *buf, size_t n) |
| 571 | { |
| 572 | int val; |
| 573 | |
| 574 | if (sscanf(buf, "%d", &val) == 1) { |
| 575 | pm_trace_enabled = !!val; |
| 576 | return n; |
| 577 | } |
| 578 | return -EINVAL; |
| 579 | } |
| 580 | |
| 581 | power_attr(pm_trace); |
| 582 | #endif /* CONFIG_PM_TRACE */ |
| 583 | |
| 584 | static struct attribute * g[] = { |
| 585 | &state_attr.attr, |
| 586 | #ifdef CONFIG_PM_TRACE |
| 587 | &pm_trace_attr.attr, |
| 588 | #endif |
| 589 | #if defined(CONFIG_PM_SLEEP) && defined(CONFIG_PM_DEBUG) |
| 590 | &pm_test_attr.attr, |
| 591 | #endif |
| 592 | NULL, |
| 593 | }; |
| 594 | |
| 595 | static struct attribute_group attr_group = { |
| 596 | .attrs = g, |
| 597 | }; |
| 598 | |
| 599 | |
| 600 | static int __init pm_init(void) |
| 601 | { |
| 602 | power_kobj = kobject_create_and_add("power", NULL); |
| 603 | if (!power_kobj) |
| 604 | return -ENOMEM; |
| 605 | return sysfs_create_group(power_kobj, &attr_group); |
| 606 | } |
| 607 | |
| 608 | core_initcall(pm_init); |
| 609 | |
| 610 | |
| 611 | #ifdef CONFIG_PM_TEST_SUSPEND |
| 612 | |
| 613 | #include <linux/rtc.h> |
| 614 | |
| 615 | /* |
| 616 | * To test system suspend, we need a hands-off mechanism to resume the |
| 617 | * system. RTCs wake alarms are a common self-contained mechanism. |
| 618 | */ |
| 619 | |
| 620 | static void __init test_wakealarm(struct rtc_device *rtc, suspend_state_t state) |
| 621 | { |
| 622 | static char err_readtime[] __initdata = |
| 623 | KERN_ERR "PM: can't read %s time, err %d\n"; |
| 624 | static char err_wakealarm [] __initdata = |
| 625 | KERN_ERR "PM: can't set %s wakealarm, err %d\n"; |
| 626 | static char err_suspend[] __initdata = |
| 627 | KERN_ERR "PM: suspend test failed, error %d\n"; |
| 628 | static char info_test[] __initdata = |
| 629 | KERN_INFO "PM: test RTC wakeup from '%s' suspend\n"; |
| 630 | |
| 631 | unsigned long now; |
| 632 | struct rtc_wkalrm alm; |
| 633 | int status; |
| 634 | |
| 635 | /* this may fail if the RTC hasn't been initialized */ |
| 636 | status = rtc_read_time(rtc, &alm.time); |
| 637 | if (status < 0) { |
| 638 | printk(err_readtime, dev_name(&rtc->dev), status); |
| 639 | return; |
| 640 | } |
| 641 | rtc_tm_to_time(&alm.time, &now); |
| 642 | |
| 643 | memset(&alm, 0, sizeof alm); |
| 644 | rtc_time_to_tm(now + TEST_SUSPEND_SECONDS, &alm.time); |
| 645 | alm.enabled = true; |
| 646 | |
| 647 | status = rtc_set_alarm(rtc, &alm); |
| 648 | if (status < 0) { |
| 649 | printk(err_wakealarm, dev_name(&rtc->dev), status); |
| 650 | return; |
| 651 | } |
| 652 | |
| 653 | if (state == PM_SUSPEND_MEM) { |
| 654 | printk(info_test, pm_states[state]); |
| 655 | status = pm_suspend(state); |
| 656 | if (status == -ENODEV) |
| 657 | state = PM_SUSPEND_STANDBY; |
| 658 | } |
| 659 | if (state == PM_SUSPEND_STANDBY) { |
| 660 | printk(info_test, pm_states[state]); |
| 661 | status = pm_suspend(state); |
| 662 | } |
| 663 | if (status < 0) |
| 664 | printk(err_suspend, status); |
| 665 | |
| 666 | /* Some platforms can't detect that the alarm triggered the |
| 667 | * wakeup, or (accordingly) disable it after it afterwards. |
| 668 | * It's supposed to give oneshot behavior; cope. |
| 669 | */ |
| 670 | alm.enabled = false; |
| 671 | rtc_set_alarm(rtc, &alm); |
| 672 | } |
| 673 | |
| 674 | static int __init has_wakealarm(struct device *dev, void *name_ptr) |
| 675 | { |
| 676 | struct rtc_device *candidate = to_rtc_device(dev); |
| 677 | |
| 678 | if (!candidate->ops->set_alarm) |
| 679 | return 0; |
| 680 | if (!device_may_wakeup(candidate->dev.parent)) |
| 681 | return 0; |
| 682 | |
| 683 | *(const char **)name_ptr = dev_name(dev); |
| 684 | return 1; |
| 685 | } |
| 686 | |
| 687 | /* |
| 688 | * Kernel options like "test_suspend=mem" force suspend/resume sanity tests |
| 689 | * at startup time. They're normally disabled, for faster boot and because |
| 690 | * we can't know which states really work on this particular system. |
| 691 | */ |
| 692 | static suspend_state_t test_state __initdata = PM_SUSPEND_ON; |
| 693 | |
| 694 | static char warn_bad_state[] __initdata = |
| 695 | KERN_WARNING "PM: can't test '%s' suspend state\n"; |
| 696 | |
| 697 | static int __init setup_test_suspend(char *value) |
| 698 | { |
| 699 | unsigned i; |
| 700 | |
| 701 | /* "=mem" ==> "mem" */ |
| 702 | value++; |
| 703 | for (i = 0; i < PM_SUSPEND_MAX; i++) { |
| 704 | if (!pm_states[i]) |
| 705 | continue; |
| 706 | if (strcmp(pm_states[i], value) != 0) |
| 707 | continue; |
| 708 | test_state = (__force suspend_state_t) i; |
| 709 | return 0; |
| 710 | } |
| 711 | printk(warn_bad_state, value); |
| 712 | return 0; |
| 713 | } |
| 714 | __setup("test_suspend", setup_test_suspend); |
| 715 | |
| 716 | static int __init test_suspend(void) |
| 717 | { |
| 718 | static char warn_no_rtc[] __initdata = |
| 719 | KERN_WARNING "PM: no wakealarm-capable RTC driver is ready\n"; |
| 720 | |
| 721 | char *pony = NULL; |
| 722 | struct rtc_device *rtc = NULL; |
| 723 | |
| 724 | /* PM is initialized by now; is that state testable? */ |
| 725 | if (test_state == PM_SUSPEND_ON) |
| 726 | goto done; |
| 727 | if (!valid_state(test_state)) { |
| 728 | printk(warn_bad_state, pm_states[test_state]); |
| 729 | goto done; |
| 730 | } |
| 731 | |
| 732 | /* RTCs have initialized by now too ... can we use one? */ |
| 733 | class_find_device(rtc_class, NULL, &pony, has_wakealarm); |
| 734 | if (pony) |
| 735 | rtc = rtc_class_open(pony); |
| 736 | if (!rtc) { |
| 737 | printk(warn_no_rtc); |
| 738 | goto done; |
| 739 | } |
| 740 | |
| 741 | /* go for it */ |
| 742 | test_wakealarm(rtc, test_state); |
| 743 | rtc_class_close(rtc); |
| 744 | done: |
| 745 | return 0; |
| 746 | } |
| 747 | late_initcall(test_suspend); |
| 748 | |
| 749 | #endif /* CONFIG_PM_TEST_SUSPEND */ |