1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Architecture-specific ACPI-based support for suspend-to-idle. 4 * 5 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 6 * Author: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> 7 * Author: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> 8 * 9 * On platforms supporting the Low Power S0 Idle interface there is an ACPI 10 * device object with the PNP0D80 compatible device ID (System Power Management 11 * Controller) and a specific _DSM method under it. That method, if present, 12 * can be used to indicate to the platform that the OS is transitioning into a 13 * low-power state in which certain types of activity are not desirable or that 14 * it is leaving such a state, which allows the platform to adjust its operation 15 * mode accordingly. 16 */ 17 18 #include <linux/acpi.h> 19 #include <linux/device.h> 20 #include <linux/dmi.h> 21 #include <linux/suspend.h> 22 23 #include "../sleep.h" 24 25 #ifdef CONFIG_SUSPEND 26 27 static bool sleep_no_lps0 __read_mostly; 28 module_param(sleep_no_lps0, bool, 0644); 29 MODULE_PARM_DESC(sleep_no_lps0, "Do not use the special LPS0 device interface"); 30 31 static bool check_lps0_constraints __read_mostly; 32 module_param(check_lps0_constraints, bool, 0644); 33 MODULE_PARM_DESC(check_lps0_constraints, "Check LPS0 device constraints"); 34 35 static const struct acpi_device_id lps0_device_ids[] = { 36 {"PNP0D80", }, 37 {"", }, 38 }; 39 40 /* Microsoft platform agnostic UUID */ 41 #define ACPI_LPS0_DSM_UUID_MICROSOFT "11e00d56-ce64-47ce-837b-1f898f9aa461" 42 43 #define ACPI_LPS0_DSM_UUID "c4eb40a0-6cd2-11e2-bcfd-0800200c9a66" 44 45 #define ACPI_LPS0_GET_DEVICE_CONSTRAINTS 1 46 #define ACPI_LPS0_SCREEN_OFF 3 47 #define ACPI_LPS0_SCREEN_ON 4 48 #define ACPI_LPS0_ENTRY 5 49 #define ACPI_LPS0_EXIT 6 50 #define ACPI_LPS0_MS_ENTRY 7 51 #define ACPI_LPS0_MS_EXIT 8 52 #define ACPI_MS_TURN_ON_DISPLAY 9 53 54 /* AMD */ 55 #define ACPI_LPS0_DSM_UUID_AMD "e3f32452-febc-43ce-9039-932122d37721" 56 #define ACPI_LPS0_ENTRY_AMD 2 57 #define ACPI_LPS0_EXIT_AMD 3 58 #define ACPI_LPS0_SCREEN_OFF_AMD 4 59 #define ACPI_LPS0_SCREEN_ON_AMD 5 60 61 static acpi_handle lps0_device_handle; 62 static guid_t lps0_dsm_guid; 63 static int lps0_dsm_func_mask; 64 65 static guid_t lps0_dsm_guid_microsoft; 66 static int lps0_dsm_func_mask_microsoft; 67 static int lps0_dsm_state; 68 69 /* Device constraint entry structure */ 70 struct lpi_device_info { 71 char *name; 72 int enabled; 73 union acpi_object *package; 74 }; 75 76 /* Constraint package structure */ 77 struct lpi_device_constraint { 78 int uid; 79 int min_dstate; 80 int function_states; 81 }; 82 83 struct lpi_constraints { 84 acpi_handle handle; 85 int min_dstate; 86 }; 87 88 /* AMD Constraint package structure */ 89 struct lpi_device_constraint_amd { 90 char *name; 91 int enabled; 92 int function_states; 93 int min_dstate; 94 }; 95 96 static LIST_HEAD(lps0_s2idle_devops_head); 97 98 static struct lpi_constraints *lpi_constraints_table; 99 static int lpi_constraints_table_size; 100 static int rev_id; 101 102 #define for_each_lpi_constraint(entry) \ 103 for (int i = 0; \ 104 entry = &lpi_constraints_table[i], i < lpi_constraints_table_size; \ 105 i++) 106 107 static void lpi_device_get_constraints_amd(void) 108 { 109 union acpi_object *out_obj; 110 int i, j, k; 111 112 out_obj = acpi_evaluate_dsm_typed(lps0_device_handle, &lps0_dsm_guid, 113 rev_id, ACPI_LPS0_GET_DEVICE_CONSTRAINTS, 114 NULL, ACPI_TYPE_PACKAGE); 115 116 acpi_handle_debug(lps0_device_handle, "_DSM function 1 eval %s\n", 117 out_obj ? "successful" : "failed"); 118 119 if (!out_obj) 120 return; 121 122 for (i = 0; i < out_obj->package.count; i++) { 123 union acpi_object *package = &out_obj->package.elements[i]; 124 125 if (package->type == ACPI_TYPE_PACKAGE) { 126 if (lpi_constraints_table) { 127 acpi_handle_err(lps0_device_handle, 128 "Duplicate constraints list\n"); 129 goto free_acpi_buffer; 130 } 131 132 lpi_constraints_table = kzalloc_objs(*lpi_constraints_table, 133 package->package.count); 134 135 if (!lpi_constraints_table) 136 goto free_acpi_buffer; 137 138 acpi_handle_debug(lps0_device_handle, 139 "LPI: constraints list begin:\n"); 140 141 for (j = 0; j < package->package.count; j++) { 142 union acpi_object *info_obj = &package->package.elements[j]; 143 struct lpi_device_constraint_amd dev_info = {}; 144 struct lpi_constraints *list; 145 acpi_status status; 146 147 list = &lpi_constraints_table[lpi_constraints_table_size]; 148 149 for (k = 0; k < info_obj->package.count; k++) { 150 union acpi_object *obj = &info_obj->package.elements[k]; 151 152 switch (k) { 153 case 0: 154 dev_info.enabled = obj->integer.value; 155 break; 156 case 1: 157 dev_info.name = obj->string.pointer; 158 break; 159 case 2: 160 dev_info.function_states = obj->integer.value; 161 break; 162 case 3: 163 dev_info.min_dstate = obj->integer.value; 164 break; 165 } 166 } 167 168 acpi_handle_debug(lps0_device_handle, 169 "Name:%s, Enabled: %d, States: %d, MinDstate: %d\n", 170 dev_info.name, 171 dev_info.enabled, 172 dev_info.function_states, 173 dev_info.min_dstate); 174 175 if (!dev_info.enabled || !dev_info.name || 176 !dev_info.min_dstate) 177 continue; 178 179 status = acpi_get_handle(NULL, dev_info.name, &list->handle); 180 if (ACPI_FAILURE(status)) 181 continue; 182 183 list->min_dstate = dev_info.min_dstate; 184 185 lpi_constraints_table_size++; 186 } 187 } 188 } 189 190 acpi_handle_debug(lps0_device_handle, "LPI: constraints list end\n"); 191 192 free_acpi_buffer: 193 ACPI_FREE(out_obj); 194 } 195 196 static void lpi_device_get_constraints(void) 197 { 198 union acpi_object *out_obj; 199 int i; 200 201 out_obj = acpi_evaluate_dsm_typed(lps0_device_handle, &lps0_dsm_guid, 202 1, ACPI_LPS0_GET_DEVICE_CONSTRAINTS, 203 NULL, ACPI_TYPE_PACKAGE); 204 205 acpi_handle_debug(lps0_device_handle, "_DSM function 1 eval %s\n", 206 out_obj ? "successful" : "failed"); 207 208 if (!out_obj) 209 return; 210 211 lpi_constraints_table = kzalloc_objs(*lpi_constraints_table, 212 out_obj->package.count); 213 if (!lpi_constraints_table) 214 goto free_acpi_buffer; 215 216 acpi_handle_debug(lps0_device_handle, "LPI: constraints list begin:\n"); 217 218 for (i = 0; i < out_obj->package.count; i++) { 219 struct lpi_constraints *constraint; 220 acpi_status status; 221 union acpi_object *package = &out_obj->package.elements[i]; 222 struct lpi_device_info info = { }; 223 int package_count = 0, j; 224 225 if (!package) 226 continue; 227 228 for (j = 0; j < package->package.count; j++) { 229 union acpi_object *element = 230 &(package->package.elements[j]); 231 232 switch (element->type) { 233 case ACPI_TYPE_INTEGER: 234 info.enabled = element->integer.value; 235 break; 236 case ACPI_TYPE_STRING: 237 info.name = element->string.pointer; 238 break; 239 case ACPI_TYPE_PACKAGE: 240 package_count = element->package.count; 241 info.package = element->package.elements; 242 break; 243 } 244 } 245 246 if (!info.enabled || !info.package || !info.name) 247 continue; 248 249 constraint = &lpi_constraints_table[lpi_constraints_table_size]; 250 251 status = acpi_get_handle(NULL, info.name, &constraint->handle); 252 if (ACPI_FAILURE(status)) 253 continue; 254 255 acpi_handle_debug(lps0_device_handle, 256 "index:%d Name:%s\n", i, info.name); 257 258 constraint->min_dstate = -1; 259 260 for (j = 0; j < package_count; j++) { 261 union acpi_object *info_obj = &info.package[j]; 262 union acpi_object *cnstr_pkg; 263 union acpi_object *obj; 264 struct lpi_device_constraint dev_info; 265 266 switch (info_obj->type) { 267 case ACPI_TYPE_INTEGER: 268 /* version */ 269 break; 270 case ACPI_TYPE_PACKAGE: 271 if (info_obj->package.count < 2) 272 break; 273 274 cnstr_pkg = info_obj->package.elements; 275 obj = &cnstr_pkg[0]; 276 dev_info.uid = obj->integer.value; 277 obj = &cnstr_pkg[1]; 278 dev_info.min_dstate = obj->integer.value; 279 280 acpi_handle_debug(lps0_device_handle, 281 "uid:%d min_dstate:%s\n", 282 dev_info.uid, 283 acpi_power_state_string(dev_info.min_dstate)); 284 285 constraint->min_dstate = dev_info.min_dstate; 286 break; 287 } 288 } 289 290 if (constraint->min_dstate < 0) { 291 acpi_handle_debug(lps0_device_handle, 292 "Incomplete constraint defined\n"); 293 continue; 294 } 295 296 lpi_constraints_table_size++; 297 } 298 299 acpi_handle_debug(lps0_device_handle, "LPI: constraints list end\n"); 300 301 free_acpi_buffer: 302 ACPI_FREE(out_obj); 303 } 304 305 static void lpi_check_constraints(void) 306 { 307 struct lpi_constraints *entry; 308 309 if (IS_ERR_OR_NULL(lpi_constraints_table)) 310 return; 311 312 for_each_lpi_constraint(entry) { 313 struct acpi_device *adev = acpi_fetch_acpi_dev(entry->handle); 314 315 if (!adev) 316 continue; 317 318 acpi_handle_debug(entry->handle, 319 "LPI: required min power state:%s current power state:%s\n", 320 acpi_power_state_string(entry->min_dstate), 321 acpi_power_state_string(adev->power.state)); 322 323 if (!adev->flags.power_manageable) { 324 acpi_handle_info(entry->handle, "LPI: Device not power manageable\n"); 325 entry->handle = NULL; 326 continue; 327 } 328 329 if (adev->power.state < entry->min_dstate) 330 acpi_handle_info(entry->handle, 331 "LPI: Constraint not met; min power state:%s current power state:%s\n", 332 acpi_power_state_string(entry->min_dstate), 333 acpi_power_state_string(adev->power.state)); 334 } 335 } 336 337 static bool acpi_s2idle_vendor_amd(void) 338 { 339 return boot_cpu_data.x86_vendor == X86_VENDOR_AMD; 340 } 341 342 static const char *acpi_sleep_dsm_state_to_str(unsigned int state) 343 { 344 if (lps0_dsm_func_mask_microsoft || !acpi_s2idle_vendor_amd()) { 345 switch (state) { 346 case ACPI_LPS0_SCREEN_OFF: 347 return "screen off"; 348 case ACPI_LPS0_SCREEN_ON: 349 return "screen on"; 350 case ACPI_LPS0_ENTRY: 351 return "lps0 entry"; 352 case ACPI_LPS0_EXIT: 353 return "lps0 exit"; 354 case ACPI_LPS0_MS_ENTRY: 355 return "lps0 ms entry"; 356 case ACPI_LPS0_MS_EXIT: 357 return "lps0 ms exit"; 358 case ACPI_MS_TURN_ON_DISPLAY: 359 return "lps0 ms turn on display"; 360 } 361 } else { 362 switch (state) { 363 case ACPI_LPS0_SCREEN_ON_AMD: 364 return "screen on"; 365 case ACPI_LPS0_SCREEN_OFF_AMD: 366 return "screen off"; 367 case ACPI_LPS0_ENTRY_AMD: 368 return "lps0 entry"; 369 case ACPI_LPS0_EXIT_AMD: 370 return "lps0 exit"; 371 } 372 } 373 374 return "unknown"; 375 } 376 377 static void acpi_sleep_run_lps0_dsm(unsigned int func, unsigned int func_mask, guid_t dsm_guid) 378 { 379 union acpi_object *out_obj; 380 381 if (!(func_mask & (1 << func))) 382 return; 383 384 out_obj = acpi_evaluate_dsm(lps0_device_handle, &dsm_guid, 385 rev_id, func, NULL); 386 ACPI_FREE(out_obj); 387 388 lps0_dsm_state = func; 389 if (pm_debug_messages_on) { 390 acpi_handle_info(lps0_device_handle, 391 "%s transitioned to state %s\n", 392 out_obj ? "Successfully" : "Failed to", 393 acpi_sleep_dsm_state_to_str(lps0_dsm_state)); 394 } 395 } 396 397 398 static int validate_dsm(acpi_handle handle, const char *uuid, int rev, guid_t *dsm_guid) 399 { 400 union acpi_object *obj; 401 int ret = -EINVAL; 402 403 guid_parse(uuid, dsm_guid); 404 405 /* Check if the _DSM is present and as expected. */ 406 obj = acpi_evaluate_dsm_typed(handle, dsm_guid, rev, 0, NULL, ACPI_TYPE_BUFFER); 407 if (!obj || obj->buffer.length == 0 || obj->buffer.length > sizeof(u32)) { 408 acpi_handle_debug(handle, 409 "_DSM UUID %s rev %d function 0 evaluation failed\n", uuid, rev); 410 goto out; 411 } 412 413 ret = *(int *)obj->buffer.pointer; 414 acpi_handle_debug(handle, "_DSM UUID %s rev %d function mask: 0x%x\n", uuid, rev, ret); 415 416 out: 417 ACPI_FREE(obj); 418 return ret; 419 } 420 421 struct amd_lps0_hid_device_data { 422 const bool check_off_by_one; 423 }; 424 425 static const struct amd_lps0_hid_device_data amd_picasso = { 426 .check_off_by_one = true, 427 }; 428 429 static const struct amd_lps0_hid_device_data amd_cezanne = { 430 .check_off_by_one = false, 431 }; 432 433 static const struct acpi_device_id amd_hid_ids[] = { 434 {"AMD0004", (kernel_ulong_t)&amd_picasso, }, 435 {"AMD0005", (kernel_ulong_t)&amd_picasso, }, 436 {"AMDI0005", (kernel_ulong_t)&amd_picasso, }, 437 {"AMDI0006", (kernel_ulong_t)&amd_cezanne, }, 438 {} 439 }; 440 441 static int lps0_device_attach(struct acpi_device *adev, 442 const struct acpi_device_id *not_used) 443 { 444 if (lps0_device_handle) 445 return 0; 446 447 lps0_dsm_func_mask_microsoft = validate_dsm(adev->handle, 448 ACPI_LPS0_DSM_UUID_MICROSOFT, 0, 449 &lps0_dsm_guid_microsoft); 450 if (acpi_s2idle_vendor_amd()) { 451 static const struct acpi_device_id *dev_id; 452 const struct amd_lps0_hid_device_data *data; 453 454 for (dev_id = &amd_hid_ids[0]; dev_id->id[0]; dev_id++) 455 if (acpi_dev_hid_uid_match(adev, dev_id->id, NULL)) 456 break; 457 if (dev_id->id[0]) 458 data = (const struct amd_lps0_hid_device_data *) dev_id->driver_data; 459 else 460 data = &amd_cezanne; 461 lps0_dsm_func_mask = validate_dsm(adev->handle, 462 ACPI_LPS0_DSM_UUID_AMD, rev_id, &lps0_dsm_guid); 463 if (lps0_dsm_func_mask > 0x3 && data->check_off_by_one) { 464 lps0_dsm_func_mask = (lps0_dsm_func_mask << 1) | 0x1; 465 acpi_handle_debug(adev->handle, "_DSM UUID %s: Adjusted function mask: 0x%x\n", 466 ACPI_LPS0_DSM_UUID_AMD, lps0_dsm_func_mask); 467 } 468 } else { 469 rev_id = 1; 470 lps0_dsm_func_mask = validate_dsm(adev->handle, 471 ACPI_LPS0_DSM_UUID, rev_id, &lps0_dsm_guid); 472 if (lps0_dsm_func_mask > 0 && lps0_dsm_func_mask_microsoft > 0) { 473 unsigned int func_mask; 474 475 /* 476 * Log a message if the _DSM function sets for two 477 * different UUIDs overlap. 478 */ 479 func_mask = lps0_dsm_func_mask & lps0_dsm_func_mask_microsoft; 480 if (func_mask) 481 acpi_handle_info(adev->handle, 482 "Duplicate LPS0 _DSM functions (mask: 0x%x)\n", 483 func_mask); 484 } 485 } 486 487 if (lps0_dsm_func_mask < 0 && lps0_dsm_func_mask_microsoft < 0) 488 return 0; //function evaluation failed 489 490 lps0_device_handle = adev->handle; 491 492 /* 493 * Use suspend-to-idle by default if ACPI_FADT_LOW_POWER_S0 is set in 494 * the FADT and the default suspend mode was not set from the command 495 * line. 496 */ 497 if ((acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0) && 498 mem_sleep_default > PM_SUSPEND_MEM && !acpi_sleep_default_s3) { 499 mem_sleep_current = PM_SUSPEND_TO_IDLE; 500 pr_info("Low-power S0 idle used by default for system suspend\n"); 501 } 502 503 /* 504 * Some LPS0 systems, like ASUS Zenbook UX430UNR/i7-8550U, require the 505 * EC GPE to be enabled while suspended for certain wakeup devices to 506 * work, so mark it as wakeup-capable. 507 */ 508 acpi_ec_mark_gpe_for_wake(); 509 510 return 0; 511 } 512 513 static struct acpi_scan_handler lps0_handler = { 514 .ids = lps0_device_ids, 515 .attach = lps0_device_attach, 516 }; 517 518 static int acpi_s2idle_begin_lps0(void) 519 { 520 if (lps0_device_handle && !sleep_no_lps0 && check_lps0_constraints && 521 !lpi_constraints_table) { 522 if (acpi_s2idle_vendor_amd()) 523 lpi_device_get_constraints_amd(); 524 else 525 lpi_device_get_constraints(); 526 527 /* 528 * Try to retrieve the constraints only once because failures 529 * to do so usually are sticky. 530 */ 531 if (!lpi_constraints_table) 532 lpi_constraints_table = ERR_PTR(-ENODATA); 533 } 534 535 return acpi_s2idle_begin(); 536 } 537 538 static int acpi_s2idle_prepare_late_lps0(void) 539 { 540 struct acpi_s2idle_dev_ops *handler; 541 542 if (!lps0_device_handle || sleep_no_lps0) 543 return 0; 544 545 if (check_lps0_constraints) 546 lpi_check_constraints(); 547 548 /* Screen off */ 549 if (lps0_dsm_func_mask > 0) 550 acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ? 551 ACPI_LPS0_SCREEN_OFF_AMD : 552 ACPI_LPS0_SCREEN_OFF, 553 lps0_dsm_func_mask, lps0_dsm_guid); 554 555 if (lps0_dsm_func_mask_microsoft > 0) 556 acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF, 557 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft); 558 559 /* LPS0 entry */ 560 if (lps0_dsm_func_mask > 0 && acpi_s2idle_vendor_amd()) 561 acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY_AMD, 562 lps0_dsm_func_mask, lps0_dsm_guid); 563 564 if (lps0_dsm_func_mask_microsoft > 0) { 565 /* Modern Standby entry */ 566 acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_ENTRY, 567 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft); 568 acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY, 569 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft); 570 } 571 572 if (lps0_dsm_func_mask > 0 && !acpi_s2idle_vendor_amd()) 573 acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY, 574 lps0_dsm_func_mask, lps0_dsm_guid); 575 576 list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) { 577 if (handler->prepare) 578 handler->prepare(); 579 } 580 581 return 0; 582 } 583 584 static void acpi_s2idle_check_lps0(void) 585 { 586 struct acpi_s2idle_dev_ops *handler; 587 588 if (!lps0_device_handle || sleep_no_lps0) 589 return; 590 591 list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) { 592 if (handler->check) 593 handler->check(); 594 } 595 } 596 597 static void acpi_s2idle_restore_early_lps0(void) 598 { 599 struct acpi_s2idle_dev_ops *handler; 600 601 if (!lps0_device_handle || sleep_no_lps0) 602 return; 603 604 list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) 605 if (handler->restore) 606 handler->restore(); 607 608 /* LPS0 exit */ 609 if (lps0_dsm_func_mask > 0) 610 acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ? 611 ACPI_LPS0_EXIT_AMD : 612 ACPI_LPS0_EXIT, 613 lps0_dsm_func_mask, lps0_dsm_guid); 614 615 if (lps0_dsm_func_mask_microsoft > 0) { 616 acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT, 617 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft); 618 /* Intent to turn on display */ 619 acpi_sleep_run_lps0_dsm(ACPI_MS_TURN_ON_DISPLAY, 620 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft); 621 /* Modern Standby exit */ 622 acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_EXIT, 623 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft); 624 } 625 626 /* Screen on */ 627 if (lps0_dsm_func_mask_microsoft > 0) 628 acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON, 629 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft); 630 if (lps0_dsm_func_mask > 0) 631 acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ? 632 ACPI_LPS0_SCREEN_ON_AMD : 633 ACPI_LPS0_SCREEN_ON, 634 lps0_dsm_func_mask, lps0_dsm_guid); 635 } 636 637 static const struct platform_s2idle_ops acpi_s2idle_ops_lps0 = { 638 .begin = acpi_s2idle_begin_lps0, 639 .prepare = acpi_s2idle_prepare, 640 .prepare_late = acpi_s2idle_prepare_late_lps0, 641 .check = acpi_s2idle_check_lps0, 642 .wake = acpi_s2idle_wake, 643 .restore_early = acpi_s2idle_restore_early_lps0, 644 .restore = acpi_s2idle_restore, 645 .end = acpi_s2idle_end, 646 }; 647 648 void __init acpi_s2idle_setup(void) 649 { 650 acpi_scan_add_handler(&lps0_handler); 651 s2idle_set_ops(&acpi_s2idle_ops_lps0); 652 } 653 654 int acpi_register_lps0_dev(struct acpi_s2idle_dev_ops *arg) 655 { 656 unsigned int sleep_flags; 657 658 if (!lps0_device_handle || sleep_no_lps0) 659 return -ENODEV; 660 661 sleep_flags = lock_system_sleep(); 662 list_add(&arg->list_node, &lps0_s2idle_devops_head); 663 unlock_system_sleep(sleep_flags); 664 665 return 0; 666 } 667 EXPORT_SYMBOL_GPL(acpi_register_lps0_dev); 668 669 void acpi_unregister_lps0_dev(struct acpi_s2idle_dev_ops *arg) 670 { 671 unsigned int sleep_flags; 672 673 if (!lps0_device_handle || sleep_no_lps0) 674 return; 675 676 sleep_flags = lock_system_sleep(); 677 list_del(&arg->list_node); 678 unlock_system_sleep(sleep_flags); 679 } 680 EXPORT_SYMBOL_GPL(acpi_unregister_lps0_dev); 681 682 #endif /* CONFIG_SUSPEND */ 683