1 /* 2 * acpi_power.c - ACPI Bus Power Management ($Revision: 39 $) 3 * 4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> 5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> 6 * 7 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License as published by 11 * the Free Software Foundation; either version 2 of the License, or (at 12 * your option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, but 15 * WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 17 * General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License along 20 * with this program; if not, write to the Free Software Foundation, Inc., 21 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. 22 * 23 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 24 */ 25 26 /* 27 * ACPI power-managed devices may be controlled in two ways: 28 * 1. via "Device Specific (D-State) Control" 29 * 2. via "Power Resource Control". 30 * This module is used to manage devices relying on Power Resource Control. 31 * 32 * An ACPI "power resource object" describes a software controllable power 33 * plane, clock plane, or other resource used by a power managed device. 34 * A device may rely on multiple power resources, and a power resource 35 * may be shared by multiple devices. 36 */ 37 38 #include <linux/kernel.h> 39 #include <linux/module.h> 40 #include <linux/init.h> 41 #include <linux/types.h> 42 #include <linux/proc_fs.h> 43 #include <linux/seq_file.h> 44 #include <acpi/acpi_bus.h> 45 #include <acpi/acpi_drivers.h> 46 47 #define _COMPONENT ACPI_POWER_COMPONENT 48 ACPI_MODULE_NAME("power"); 49 #define ACPI_POWER_COMPONENT 0x00800000 50 #define ACPI_POWER_CLASS "power_resource" 51 #define ACPI_POWER_DEVICE_NAME "Power Resource" 52 #define ACPI_POWER_FILE_INFO "info" 53 #define ACPI_POWER_FILE_STATUS "state" 54 #define ACPI_POWER_RESOURCE_STATE_OFF 0x00 55 #define ACPI_POWER_RESOURCE_STATE_ON 0x01 56 #define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF 57 static int acpi_power_add(struct acpi_device *device); 58 static int acpi_power_remove(struct acpi_device *device, int type); 59 static int acpi_power_resume(struct acpi_device *device); 60 static int acpi_power_open_fs(struct inode *inode, struct file *file); 61 62 static struct acpi_driver acpi_power_driver = { 63 .name = "power", 64 .class = ACPI_POWER_CLASS, 65 .ids = ACPI_POWER_HID, 66 .ops = { 67 .add = acpi_power_add, 68 .remove = acpi_power_remove, 69 .resume = acpi_power_resume, 70 }, 71 }; 72 73 struct acpi_power_reference { 74 struct list_head node; 75 struct acpi_device *device; 76 }; 77 78 struct acpi_power_resource { 79 struct acpi_device * device; 80 acpi_bus_id name; 81 u32 system_level; 82 u32 order; 83 int state; 84 struct mutex resource_lock; 85 struct list_head reference; 86 }; 87 88 static struct list_head acpi_power_resource_list; 89 90 static const struct file_operations acpi_power_fops = { 91 .open = acpi_power_open_fs, 92 .read = seq_read, 93 .llseek = seq_lseek, 94 .release = single_release, 95 }; 96 97 /* -------------------------------------------------------------------------- 98 Power Resource Management 99 -------------------------------------------------------------------------- */ 100 101 static int 102 acpi_power_get_context(acpi_handle handle, 103 struct acpi_power_resource **resource) 104 { 105 int result = 0; 106 struct acpi_device *device = NULL; 107 108 109 if (!resource) 110 return -ENODEV; 111 112 result = acpi_bus_get_device(handle, &device); 113 if (result) { 114 printk(KERN_WARNING PREFIX "Getting context [%p]\n", handle); 115 return result; 116 } 117 118 *resource = acpi_driver_data(device); 119 if (!resource) 120 return -ENODEV; 121 122 return 0; 123 } 124 125 static int acpi_power_get_state(struct acpi_power_resource *resource) 126 { 127 acpi_status status = AE_OK; 128 unsigned long sta = 0; 129 130 131 if (!resource) 132 return -EINVAL; 133 134 status = acpi_evaluate_integer(resource->device->handle, "_STA", NULL, &sta); 135 if (ACPI_FAILURE(status)) 136 return -ENODEV; 137 138 if (sta & 0x01) 139 resource->state = ACPI_POWER_RESOURCE_STATE_ON; 140 else 141 resource->state = ACPI_POWER_RESOURCE_STATE_OFF; 142 143 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n", 144 resource->name, resource->state ? "on" : "off")); 145 146 return 0; 147 } 148 149 static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state) 150 { 151 int result = 0; 152 struct acpi_power_resource *resource = NULL; 153 u32 i = 0; 154 155 156 if (!list || !state) 157 return -EINVAL; 158 159 /* The state of the list is 'on' IFF all resources are 'on'. */ 160 161 for (i = 0; i < list->count; i++) { 162 result = acpi_power_get_context(list->handles[i], &resource); 163 if (result) 164 return result; 165 result = acpi_power_get_state(resource); 166 if (result) 167 return result; 168 169 *state = resource->state; 170 171 if (*state != ACPI_POWER_RESOURCE_STATE_ON) 172 break; 173 } 174 175 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n", 176 *state ? "on" : "off")); 177 178 return result; 179 } 180 181 static int acpi_power_on(acpi_handle handle, struct acpi_device *dev) 182 { 183 int result = 0; 184 int found = 0; 185 acpi_status status = AE_OK; 186 struct acpi_power_resource *resource = NULL; 187 struct list_head *node, *next; 188 struct acpi_power_reference *ref; 189 190 191 result = acpi_power_get_context(handle, &resource); 192 if (result) 193 return result; 194 195 mutex_lock(&resource->resource_lock); 196 list_for_each_safe(node, next, &resource->reference) { 197 ref = container_of(node, struct acpi_power_reference, node); 198 if (dev->handle == ref->device->handle) { 199 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already referenced by resource [%s]\n", 200 dev->pnp.bus_id, resource->name)); 201 found = 1; 202 break; 203 } 204 } 205 206 if (!found) { 207 ref = kmalloc(sizeof (struct acpi_power_reference), 208 irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL); 209 if (!ref) { 210 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "kmalloc() failed\n")); 211 mutex_unlock(&resource->resource_lock); 212 return -ENOMEM; 213 } 214 list_add_tail(&ref->node, &resource->reference); 215 ref->device = dev; 216 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] added to resource [%s] references\n", 217 dev->pnp.bus_id, resource->name)); 218 } 219 mutex_unlock(&resource->resource_lock); 220 221 if (resource->state == ACPI_POWER_RESOURCE_STATE_ON) { 222 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] already on\n", 223 resource->name)); 224 return 0; 225 } 226 227 status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL); 228 if (ACPI_FAILURE(status)) 229 return -ENODEV; 230 231 result = acpi_power_get_state(resource); 232 if (result) 233 return result; 234 if (resource->state != ACPI_POWER_RESOURCE_STATE_ON) 235 return -ENOEXEC; 236 237 /* Update the power resource's _device_ power state */ 238 resource->device->power.state = ACPI_STATE_D0; 239 240 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned on\n", 241 resource->name)); 242 return 0; 243 } 244 245 static int acpi_power_off_device(acpi_handle handle, struct acpi_device *dev) 246 { 247 int result = 0; 248 acpi_status status = AE_OK; 249 struct acpi_power_resource *resource = NULL; 250 struct list_head *node, *next; 251 struct acpi_power_reference *ref; 252 253 254 result = acpi_power_get_context(handle, &resource); 255 if (result) 256 return result; 257 258 mutex_lock(&resource->resource_lock); 259 list_for_each_safe(node, next, &resource->reference) { 260 ref = container_of(node, struct acpi_power_reference, node); 261 if (dev->handle == ref->device->handle) { 262 list_del(&ref->node); 263 kfree(ref); 264 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] removed from resource [%s] references\n", 265 dev->pnp.bus_id, resource->name)); 266 break; 267 } 268 } 269 270 if (!list_empty(&resource->reference)) { 271 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Cannot turn resource [%s] off - resource is in use\n", 272 resource->name)); 273 mutex_unlock(&resource->resource_lock); 274 return 0; 275 } 276 mutex_unlock(&resource->resource_lock); 277 278 if (resource->state == ACPI_POWER_RESOURCE_STATE_OFF) { 279 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] already off\n", 280 resource->name)); 281 return 0; 282 } 283 284 status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL); 285 if (ACPI_FAILURE(status)) 286 return -ENODEV; 287 288 result = acpi_power_get_state(resource); 289 if (result) 290 return result; 291 if (resource->state != ACPI_POWER_RESOURCE_STATE_OFF) 292 return -ENOEXEC; 293 294 /* Update the power resource's _device_ power state */ 295 resource->device->power.state = ACPI_STATE_D3; 296 297 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned off\n", 298 resource->name)); 299 300 return 0; 301 } 302 303 /* 304 * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229): 305 * 1. Power on the power resources required for the wakeup device 306 * 2. Enable _PSW (power state wake) for the device if present 307 */ 308 int acpi_enable_wakeup_device_power(struct acpi_device *dev) 309 { 310 union acpi_object arg = { ACPI_TYPE_INTEGER }; 311 struct acpi_object_list arg_list = { 1, &arg }; 312 acpi_status status = AE_OK; 313 int i; 314 int ret = 0; 315 316 if (!dev || !dev->wakeup.flags.valid) 317 return -1; 318 319 arg.integer.value = 1; 320 /* Open power resource */ 321 for (i = 0; i < dev->wakeup.resources.count; i++) { 322 ret = acpi_power_on(dev->wakeup.resources.handles[i], dev); 323 if (ret) { 324 printk(KERN_ERR PREFIX "Transition power state\n"); 325 dev->wakeup.flags.valid = 0; 326 return -1; 327 } 328 } 329 330 /* Execute PSW */ 331 status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL); 332 if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) { 333 printk(KERN_ERR PREFIX "Evaluate _PSW\n"); 334 dev->wakeup.flags.valid = 0; 335 ret = -1; 336 } 337 338 return ret; 339 } 340 341 /* 342 * Shutdown a wakeup device, counterpart of above method 343 * 1. Disable _PSW (power state wake) 344 * 2. Shutdown down the power resources 345 */ 346 int acpi_disable_wakeup_device_power(struct acpi_device *dev) 347 { 348 union acpi_object arg = { ACPI_TYPE_INTEGER }; 349 struct acpi_object_list arg_list = { 1, &arg }; 350 acpi_status status = AE_OK; 351 int i; 352 int ret = 0; 353 354 355 if (!dev || !dev->wakeup.flags.valid) 356 return -1; 357 358 arg.integer.value = 0; 359 /* Execute PSW */ 360 status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL); 361 if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) { 362 printk(KERN_ERR PREFIX "Evaluate _PSW\n"); 363 dev->wakeup.flags.valid = 0; 364 return -1; 365 } 366 367 /* Close power resource */ 368 for (i = 0; i < dev->wakeup.resources.count; i++) { 369 ret = acpi_power_off_device(dev->wakeup.resources.handles[i], dev); 370 if (ret) { 371 printk(KERN_ERR PREFIX "Transition power state\n"); 372 dev->wakeup.flags.valid = 0; 373 return -1; 374 } 375 } 376 377 return ret; 378 } 379 380 /* -------------------------------------------------------------------------- 381 Device Power Management 382 -------------------------------------------------------------------------- */ 383 384 int acpi_power_get_inferred_state(struct acpi_device *device) 385 { 386 int result = 0; 387 struct acpi_handle_list *list = NULL; 388 int list_state = 0; 389 int i = 0; 390 391 392 if (!device) 393 return -EINVAL; 394 395 device->power.state = ACPI_STATE_UNKNOWN; 396 397 /* 398 * We know a device's inferred power state when all the resources 399 * required for a given D-state are 'on'. 400 */ 401 for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) { 402 list = &device->power.states[i].resources; 403 if (list->count < 1) 404 continue; 405 406 result = acpi_power_get_list_state(list, &list_state); 407 if (result) 408 return result; 409 410 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) { 411 device->power.state = i; 412 return 0; 413 } 414 } 415 416 device->power.state = ACPI_STATE_D3; 417 418 return 0; 419 } 420 421 int acpi_power_transition(struct acpi_device *device, int state) 422 { 423 int result = 0; 424 struct acpi_handle_list *cl = NULL; /* Current Resources */ 425 struct acpi_handle_list *tl = NULL; /* Target Resources */ 426 int i = 0; 427 428 429 if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3)) 430 return -EINVAL; 431 432 if ((device->power.state < ACPI_STATE_D0) 433 || (device->power.state > ACPI_STATE_D3)) 434 return -ENODEV; 435 436 cl = &device->power.states[device->power.state].resources; 437 tl = &device->power.states[state].resources; 438 439 if (!cl->count && !tl->count) { 440 result = -ENODEV; 441 goto end; 442 } 443 444 /* TBD: Resources must be ordered. */ 445 446 /* 447 * First we reference all power resources required in the target list 448 * (e.g. so the device doesn't lose power while transitioning). 449 */ 450 for (i = 0; i < tl->count; i++) { 451 result = acpi_power_on(tl->handles[i], device); 452 if (result) 453 goto end; 454 } 455 456 if (device->power.state == state) { 457 goto end; 458 } 459 460 /* 461 * Then we dereference all power resources used in the current list. 462 */ 463 for (i = 0; i < cl->count; i++) { 464 result = acpi_power_off_device(cl->handles[i], device); 465 if (result) 466 goto end; 467 } 468 469 end: 470 if (result) { 471 device->power.state = ACPI_STATE_UNKNOWN; 472 printk(KERN_WARNING PREFIX "Transitioning device [%s] to D%d\n", 473 device->pnp.bus_id, state); 474 } else { 475 /* We shouldn't change the state till all above operations succeed */ 476 device->power.state = state; 477 } 478 479 return result; 480 } 481 482 /* -------------------------------------------------------------------------- 483 FS Interface (/proc) 484 -------------------------------------------------------------------------- */ 485 486 static struct proc_dir_entry *acpi_power_dir; 487 488 static int acpi_power_seq_show(struct seq_file *seq, void *offset) 489 { 490 int count = 0; 491 int result = 0; 492 struct acpi_power_resource *resource = NULL; 493 struct list_head *node, *next; 494 struct acpi_power_reference *ref; 495 496 497 resource = seq->private; 498 499 if (!resource) 500 goto end; 501 502 result = acpi_power_get_state(resource); 503 if (result) 504 goto end; 505 506 seq_puts(seq, "state: "); 507 switch (resource->state) { 508 case ACPI_POWER_RESOURCE_STATE_ON: 509 seq_puts(seq, "on\n"); 510 break; 511 case ACPI_POWER_RESOURCE_STATE_OFF: 512 seq_puts(seq, "off\n"); 513 break; 514 default: 515 seq_puts(seq, "unknown\n"); 516 break; 517 } 518 519 mutex_lock(&resource->resource_lock); 520 list_for_each_safe(node, next, &resource->reference) { 521 ref = container_of(node, struct acpi_power_reference, node); 522 count++; 523 } 524 mutex_unlock(&resource->resource_lock); 525 526 seq_printf(seq, "system level: S%d\n" 527 "order: %d\n" 528 "reference count: %d\n", 529 resource->system_level, 530 resource->order, count); 531 532 end: 533 return 0; 534 } 535 536 static int acpi_power_open_fs(struct inode *inode, struct file *file) 537 { 538 return single_open(file, acpi_power_seq_show, PDE(inode)->data); 539 } 540 541 static int acpi_power_add_fs(struct acpi_device *device) 542 { 543 struct proc_dir_entry *entry = NULL; 544 545 546 if (!device) 547 return -EINVAL; 548 549 if (!acpi_device_dir(device)) { 550 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device), 551 acpi_power_dir); 552 if (!acpi_device_dir(device)) 553 return -ENODEV; 554 } 555 556 /* 'status' [R] */ 557 entry = create_proc_entry(ACPI_POWER_FILE_STATUS, 558 S_IRUGO, acpi_device_dir(device)); 559 if (!entry) 560 return -EIO; 561 else { 562 entry->proc_fops = &acpi_power_fops; 563 entry->data = acpi_driver_data(device); 564 } 565 566 return 0; 567 } 568 569 static int acpi_power_remove_fs(struct acpi_device *device) 570 { 571 572 if (acpi_device_dir(device)) { 573 remove_proc_entry(ACPI_POWER_FILE_STATUS, 574 acpi_device_dir(device)); 575 remove_proc_entry(acpi_device_bid(device), acpi_power_dir); 576 acpi_device_dir(device) = NULL; 577 } 578 579 return 0; 580 } 581 582 /* -------------------------------------------------------------------------- 583 Driver Interface 584 -------------------------------------------------------------------------- */ 585 586 static int acpi_power_add(struct acpi_device *device) 587 { 588 int result = 0; 589 acpi_status status = AE_OK; 590 struct acpi_power_resource *resource = NULL; 591 union acpi_object acpi_object; 592 struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object }; 593 594 595 if (!device) 596 return -EINVAL; 597 598 resource = kzalloc(sizeof(struct acpi_power_resource), GFP_KERNEL); 599 if (!resource) 600 return -ENOMEM; 601 602 resource->device = device; 603 mutex_init(&resource->resource_lock); 604 INIT_LIST_HEAD(&resource->reference); 605 strcpy(resource->name, device->pnp.bus_id); 606 strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME); 607 strcpy(acpi_device_class(device), ACPI_POWER_CLASS); 608 acpi_driver_data(device) = resource; 609 610 /* Evalute the object to get the system level and resource order. */ 611 status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer); 612 if (ACPI_FAILURE(status)) { 613 result = -ENODEV; 614 goto end; 615 } 616 resource->system_level = acpi_object.power_resource.system_level; 617 resource->order = acpi_object.power_resource.resource_order; 618 619 result = acpi_power_get_state(resource); 620 if (result) 621 goto end; 622 623 switch (resource->state) { 624 case ACPI_POWER_RESOURCE_STATE_ON: 625 device->power.state = ACPI_STATE_D0; 626 break; 627 case ACPI_POWER_RESOURCE_STATE_OFF: 628 device->power.state = ACPI_STATE_D3; 629 break; 630 default: 631 device->power.state = ACPI_STATE_UNKNOWN; 632 break; 633 } 634 635 result = acpi_power_add_fs(device); 636 if (result) 637 goto end; 638 639 printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device), 640 acpi_device_bid(device), resource->state ? "on" : "off"); 641 642 end: 643 if (result) 644 kfree(resource); 645 646 return result; 647 } 648 649 static int acpi_power_remove(struct acpi_device *device, int type) 650 { 651 struct acpi_power_resource *resource = NULL; 652 struct list_head *node, *next; 653 654 655 if (!device || !acpi_driver_data(device)) 656 return -EINVAL; 657 658 resource = acpi_driver_data(device); 659 660 acpi_power_remove_fs(device); 661 662 mutex_lock(&resource->resource_lock); 663 list_for_each_safe(node, next, &resource->reference) { 664 struct acpi_power_reference *ref = container_of(node, struct acpi_power_reference, node); 665 list_del(&ref->node); 666 kfree(ref); 667 } 668 mutex_unlock(&resource->resource_lock); 669 670 kfree(resource); 671 672 return 0; 673 } 674 675 static int acpi_power_resume(struct acpi_device *device) 676 { 677 int result = 0; 678 struct acpi_power_resource *resource = NULL; 679 struct acpi_power_reference *ref; 680 681 if (!device || !acpi_driver_data(device)) 682 return -EINVAL; 683 684 resource = (struct acpi_power_resource *)acpi_driver_data(device); 685 686 result = acpi_power_get_state(resource); 687 if (result) 688 return result; 689 690 mutex_lock(&resource->resource_lock); 691 if ((resource->state == ACPI_POWER_RESOURCE_STATE_OFF) && 692 !list_empty(&resource->reference)) { 693 ref = container_of(resource->reference.next, struct acpi_power_reference, node); 694 mutex_unlock(&resource->resource_lock); 695 result = acpi_power_on(device->handle, ref->device); 696 return result; 697 } 698 699 mutex_unlock(&resource->resource_lock); 700 return 0; 701 } 702 703 static int __init acpi_power_init(void) 704 { 705 int result = 0; 706 707 708 if (acpi_disabled) 709 return 0; 710 711 INIT_LIST_HEAD(&acpi_power_resource_list); 712 713 acpi_power_dir = proc_mkdir(ACPI_POWER_CLASS, acpi_root_dir); 714 if (!acpi_power_dir) 715 return -ENODEV; 716 717 result = acpi_bus_register_driver(&acpi_power_driver); 718 if (result < 0) { 719 remove_proc_entry(ACPI_POWER_CLASS, acpi_root_dir); 720 return -ENODEV; 721 } 722 723 return 0; 724 } 725 726 subsys_initcall(acpi_power_init); 727