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_device_id power_device_ids[] = { 63 {ACPI_POWER_HID, 0}, 64 {"", 0}, 65 }; 66 MODULE_DEVICE_TABLE(acpi, power_device_ids); 67 68 static struct acpi_driver acpi_power_driver = { 69 .name = "power", 70 .class = ACPI_POWER_CLASS, 71 .ids = power_device_ids, 72 .ops = { 73 .add = acpi_power_add, 74 .remove = acpi_power_remove, 75 .resume = acpi_power_resume, 76 }, 77 }; 78 79 struct acpi_power_reference { 80 struct list_head node; 81 struct acpi_device *device; 82 }; 83 84 struct acpi_power_resource { 85 struct acpi_device * device; 86 acpi_bus_id name; 87 u32 system_level; 88 u32 order; 89 struct mutex resource_lock; 90 struct list_head reference; 91 }; 92 93 static struct list_head acpi_power_resource_list; 94 95 static const struct file_operations acpi_power_fops = { 96 .open = acpi_power_open_fs, 97 .read = seq_read, 98 .llseek = seq_lseek, 99 .release = single_release, 100 }; 101 102 /* -------------------------------------------------------------------------- 103 Power Resource Management 104 -------------------------------------------------------------------------- */ 105 106 static int 107 acpi_power_get_context(acpi_handle handle, 108 struct acpi_power_resource **resource) 109 { 110 int result = 0; 111 struct acpi_device *device = NULL; 112 113 114 if (!resource) 115 return -ENODEV; 116 117 result = acpi_bus_get_device(handle, &device); 118 if (result) { 119 printk(KERN_WARNING PREFIX "Getting context [%p]\n", handle); 120 return result; 121 } 122 123 *resource = acpi_driver_data(device); 124 if (!resource) 125 return -ENODEV; 126 127 return 0; 128 } 129 130 static int acpi_power_get_state(struct acpi_power_resource *resource, int *state) 131 { 132 acpi_status status = AE_OK; 133 unsigned long sta = 0; 134 135 136 if (!resource || !state) 137 return -EINVAL; 138 139 status = acpi_evaluate_integer(resource->device->handle, "_STA", NULL, &sta); 140 if (ACPI_FAILURE(status)) 141 return -ENODEV; 142 143 *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON: 144 ACPI_POWER_RESOURCE_STATE_OFF; 145 146 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n", 147 resource->name, state ? "on" : "off")); 148 149 return 0; 150 } 151 152 static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state) 153 { 154 int result = 0, state1; 155 struct acpi_power_resource *resource = NULL; 156 u32 i = 0; 157 158 159 if (!list || !state) 160 return -EINVAL; 161 162 /* The state of the list is 'on' IFF all resources are 'on'. */ 163 164 for (i = 0; i < list->count; i++) { 165 result = acpi_power_get_context(list->handles[i], &resource); 166 if (result) 167 return result; 168 result = acpi_power_get_state(resource, &state1); 169 if (result) 170 return result; 171 172 *state = state1; 173 174 if (*state != ACPI_POWER_RESOURCE_STATE_ON) 175 break; 176 } 177 178 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n", 179 *state ? "on" : "off")); 180 181 return result; 182 } 183 184 static int acpi_power_on(acpi_handle handle, struct acpi_device *dev) 185 { 186 int result = 0, state; 187 int found = 0; 188 acpi_status status = AE_OK; 189 struct acpi_power_resource *resource = NULL; 190 struct list_head *node, *next; 191 struct acpi_power_reference *ref; 192 193 194 result = acpi_power_get_context(handle, &resource); 195 if (result) 196 return result; 197 198 mutex_lock(&resource->resource_lock); 199 list_for_each_safe(node, next, &resource->reference) { 200 ref = container_of(node, struct acpi_power_reference, node); 201 if (dev->handle == ref->device->handle) { 202 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already referenced by resource [%s]\n", 203 dev->pnp.bus_id, resource->name)); 204 found = 1; 205 break; 206 } 207 } 208 209 if (!found) { 210 ref = kmalloc(sizeof (struct acpi_power_reference), 211 irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL); 212 if (!ref) { 213 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "kmalloc() failed\n")); 214 mutex_unlock(&resource->resource_lock); 215 return -ENOMEM; 216 } 217 list_add_tail(&ref->node, &resource->reference); 218 ref->device = dev; 219 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] added to resource [%s] references\n", 220 dev->pnp.bus_id, resource->name)); 221 } 222 mutex_unlock(&resource->resource_lock); 223 224 status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL); 225 if (ACPI_FAILURE(status)) 226 return -ENODEV; 227 228 result = acpi_power_get_state(resource, &state); 229 if (result) 230 return result; 231 if (state != ACPI_POWER_RESOURCE_STATE_ON) 232 return -ENOEXEC; 233 234 /* Update the power resource's _device_ power state */ 235 resource->device->power.state = ACPI_STATE_D0; 236 237 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned on\n", 238 resource->name)); 239 return 0; 240 } 241 242 static int acpi_power_off_device(acpi_handle handle, struct acpi_device *dev) 243 { 244 int result = 0, state; 245 acpi_status status = AE_OK; 246 struct acpi_power_resource *resource = NULL; 247 struct list_head *node, *next; 248 struct acpi_power_reference *ref; 249 250 251 result = acpi_power_get_context(handle, &resource); 252 if (result) 253 return result; 254 255 mutex_lock(&resource->resource_lock); 256 list_for_each_safe(node, next, &resource->reference) { 257 ref = container_of(node, struct acpi_power_reference, node); 258 if (dev->handle == ref->device->handle) { 259 list_del(&ref->node); 260 kfree(ref); 261 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] removed from resource [%s] references\n", 262 dev->pnp.bus_id, resource->name)); 263 break; 264 } 265 } 266 267 if (!list_empty(&resource->reference)) { 268 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Cannot turn resource [%s] off - resource is in use\n", 269 resource->name)); 270 mutex_unlock(&resource->resource_lock); 271 return 0; 272 } 273 mutex_unlock(&resource->resource_lock); 274 275 status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL); 276 if (ACPI_FAILURE(status)) 277 return -ENODEV; 278 279 result = acpi_power_get_state(resource, &state); 280 if (result) 281 return result; 282 if (state != ACPI_POWER_RESOURCE_STATE_OFF) 283 return -ENOEXEC; 284 285 /* Update the power resource's _device_ power state */ 286 resource->device->power.state = ACPI_STATE_D3; 287 288 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned off\n", 289 resource->name)); 290 291 return 0; 292 } 293 294 /* 295 * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229): 296 * 1. Power on the power resources required for the wakeup device 297 * 2. Enable _PSW (power state wake) for the device if present 298 */ 299 int acpi_enable_wakeup_device_power(struct acpi_device *dev) 300 { 301 union acpi_object arg = { ACPI_TYPE_INTEGER }; 302 struct acpi_object_list arg_list = { 1, &arg }; 303 acpi_status status = AE_OK; 304 int i; 305 int ret = 0; 306 307 if (!dev || !dev->wakeup.flags.valid) 308 return -1; 309 310 arg.integer.value = 1; 311 /* Open power resource */ 312 for (i = 0; i < dev->wakeup.resources.count; i++) { 313 ret = acpi_power_on(dev->wakeup.resources.handles[i], dev); 314 if (ret) { 315 printk(KERN_ERR PREFIX "Transition power state\n"); 316 dev->wakeup.flags.valid = 0; 317 return -1; 318 } 319 } 320 321 /* Execute PSW */ 322 status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL); 323 if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) { 324 printk(KERN_ERR PREFIX "Evaluate _PSW\n"); 325 dev->wakeup.flags.valid = 0; 326 ret = -1; 327 } 328 329 return ret; 330 } 331 332 /* 333 * Shutdown a wakeup device, counterpart of above method 334 * 1. Disable _PSW (power state wake) 335 * 2. Shutdown down the power resources 336 */ 337 int acpi_disable_wakeup_device_power(struct acpi_device *dev) 338 { 339 union acpi_object arg = { ACPI_TYPE_INTEGER }; 340 struct acpi_object_list arg_list = { 1, &arg }; 341 acpi_status status = AE_OK; 342 int i; 343 int ret = 0; 344 345 346 if (!dev || !dev->wakeup.flags.valid) 347 return -1; 348 349 arg.integer.value = 0; 350 /* Execute PSW */ 351 status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL); 352 if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) { 353 printk(KERN_ERR PREFIX "Evaluate _PSW\n"); 354 dev->wakeup.flags.valid = 0; 355 return -1; 356 } 357 358 /* Close power resource */ 359 for (i = 0; i < dev->wakeup.resources.count; i++) { 360 ret = acpi_power_off_device(dev->wakeup.resources.handles[i], dev); 361 if (ret) { 362 printk(KERN_ERR PREFIX "Transition power state\n"); 363 dev->wakeup.flags.valid = 0; 364 return -1; 365 } 366 } 367 368 return ret; 369 } 370 371 /* -------------------------------------------------------------------------- 372 Device Power Management 373 -------------------------------------------------------------------------- */ 374 375 int acpi_power_get_inferred_state(struct acpi_device *device) 376 { 377 int result = 0; 378 struct acpi_handle_list *list = NULL; 379 int list_state = 0; 380 int i = 0; 381 382 383 if (!device) 384 return -EINVAL; 385 386 device->power.state = ACPI_STATE_UNKNOWN; 387 388 /* 389 * We know a device's inferred power state when all the resources 390 * required for a given D-state are 'on'. 391 */ 392 for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) { 393 list = &device->power.states[i].resources; 394 if (list->count < 1) 395 continue; 396 397 result = acpi_power_get_list_state(list, &list_state); 398 if (result) 399 return result; 400 401 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) { 402 device->power.state = i; 403 return 0; 404 } 405 } 406 407 device->power.state = ACPI_STATE_D3; 408 409 return 0; 410 } 411 412 int acpi_power_transition(struct acpi_device *device, int state) 413 { 414 int result = 0; 415 struct acpi_handle_list *cl = NULL; /* Current Resources */ 416 struct acpi_handle_list *tl = NULL; /* Target Resources */ 417 int i = 0; 418 419 420 if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3)) 421 return -EINVAL; 422 423 if ((device->power.state < ACPI_STATE_D0) 424 || (device->power.state > ACPI_STATE_D3)) 425 return -ENODEV; 426 427 cl = &device->power.states[device->power.state].resources; 428 tl = &device->power.states[state].resources; 429 430 if (!cl->count && !tl->count) { 431 result = -ENODEV; 432 goto end; 433 } 434 435 /* TBD: Resources must be ordered. */ 436 437 /* 438 * First we reference all power resources required in the target list 439 * (e.g. so the device doesn't lose power while transitioning). 440 */ 441 for (i = 0; i < tl->count; i++) { 442 result = acpi_power_on(tl->handles[i], device); 443 if (result) 444 goto end; 445 } 446 447 if (device->power.state == state) { 448 goto end; 449 } 450 451 /* 452 * Then we dereference all power resources used in the current list. 453 */ 454 for (i = 0; i < cl->count; i++) { 455 result = acpi_power_off_device(cl->handles[i], device); 456 if (result) 457 goto end; 458 } 459 460 end: 461 if (result) 462 device->power.state = ACPI_STATE_UNKNOWN; 463 else { 464 /* We shouldn't change the state till all above operations succeed */ 465 device->power.state = state; 466 } 467 468 return result; 469 } 470 471 /* -------------------------------------------------------------------------- 472 FS Interface (/proc) 473 -------------------------------------------------------------------------- */ 474 475 static struct proc_dir_entry *acpi_power_dir; 476 477 static int acpi_power_seq_show(struct seq_file *seq, void *offset) 478 { 479 int count = 0; 480 int result = 0, state; 481 struct acpi_power_resource *resource = NULL; 482 struct list_head *node, *next; 483 struct acpi_power_reference *ref; 484 485 486 resource = seq->private; 487 488 if (!resource) 489 goto end; 490 491 result = acpi_power_get_state(resource, &state); 492 if (result) 493 goto end; 494 495 seq_puts(seq, "state: "); 496 switch (state) { 497 case ACPI_POWER_RESOURCE_STATE_ON: 498 seq_puts(seq, "on\n"); 499 break; 500 case ACPI_POWER_RESOURCE_STATE_OFF: 501 seq_puts(seq, "off\n"); 502 break; 503 default: 504 seq_puts(seq, "unknown\n"); 505 break; 506 } 507 508 mutex_lock(&resource->resource_lock); 509 list_for_each_safe(node, next, &resource->reference) { 510 ref = container_of(node, struct acpi_power_reference, node); 511 count++; 512 } 513 mutex_unlock(&resource->resource_lock); 514 515 seq_printf(seq, "system level: S%d\n" 516 "order: %d\n" 517 "reference count: %d\n", 518 resource->system_level, 519 resource->order, count); 520 521 end: 522 return 0; 523 } 524 525 static int acpi_power_open_fs(struct inode *inode, struct file *file) 526 { 527 return single_open(file, acpi_power_seq_show, PDE(inode)->data); 528 } 529 530 static int acpi_power_add_fs(struct acpi_device *device) 531 { 532 struct proc_dir_entry *entry = NULL; 533 534 535 if (!device) 536 return -EINVAL; 537 538 if (!acpi_device_dir(device)) { 539 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device), 540 acpi_power_dir); 541 if (!acpi_device_dir(device)) 542 return -ENODEV; 543 } 544 545 /* 'status' [R] */ 546 entry = create_proc_entry(ACPI_POWER_FILE_STATUS, 547 S_IRUGO, acpi_device_dir(device)); 548 if (!entry) 549 return -EIO; 550 else { 551 entry->proc_fops = &acpi_power_fops; 552 entry->data = acpi_driver_data(device); 553 } 554 555 return 0; 556 } 557 558 static int acpi_power_remove_fs(struct acpi_device *device) 559 { 560 561 if (acpi_device_dir(device)) { 562 remove_proc_entry(ACPI_POWER_FILE_STATUS, 563 acpi_device_dir(device)); 564 remove_proc_entry(acpi_device_bid(device), acpi_power_dir); 565 acpi_device_dir(device) = NULL; 566 } 567 568 return 0; 569 } 570 571 /* -------------------------------------------------------------------------- 572 Driver Interface 573 -------------------------------------------------------------------------- */ 574 575 static int acpi_power_add(struct acpi_device *device) 576 { 577 int result = 0, state; 578 acpi_status status = AE_OK; 579 struct acpi_power_resource *resource = NULL; 580 union acpi_object acpi_object; 581 struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object }; 582 583 584 if (!device) 585 return -EINVAL; 586 587 resource = kzalloc(sizeof(struct acpi_power_resource), GFP_KERNEL); 588 if (!resource) 589 return -ENOMEM; 590 591 resource->device = device; 592 mutex_init(&resource->resource_lock); 593 INIT_LIST_HEAD(&resource->reference); 594 strcpy(resource->name, device->pnp.bus_id); 595 strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME); 596 strcpy(acpi_device_class(device), ACPI_POWER_CLASS); 597 acpi_driver_data(device) = resource; 598 599 /* Evalute the object to get the system level and resource order. */ 600 status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer); 601 if (ACPI_FAILURE(status)) { 602 result = -ENODEV; 603 goto end; 604 } 605 resource->system_level = acpi_object.power_resource.system_level; 606 resource->order = acpi_object.power_resource.resource_order; 607 608 result = acpi_power_get_state(resource, &state); 609 if (result) 610 goto end; 611 612 switch (state) { 613 case ACPI_POWER_RESOURCE_STATE_ON: 614 device->power.state = ACPI_STATE_D0; 615 break; 616 case ACPI_POWER_RESOURCE_STATE_OFF: 617 device->power.state = ACPI_STATE_D3; 618 break; 619 default: 620 device->power.state = ACPI_STATE_UNKNOWN; 621 break; 622 } 623 624 result = acpi_power_add_fs(device); 625 if (result) 626 goto end; 627 628 printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device), 629 acpi_device_bid(device), state ? "on" : "off"); 630 631 end: 632 if (result) 633 kfree(resource); 634 635 return result; 636 } 637 638 static int acpi_power_remove(struct acpi_device *device, int type) 639 { 640 struct acpi_power_resource *resource = NULL; 641 struct list_head *node, *next; 642 643 644 if (!device || !acpi_driver_data(device)) 645 return -EINVAL; 646 647 resource = acpi_driver_data(device); 648 649 acpi_power_remove_fs(device); 650 651 mutex_lock(&resource->resource_lock); 652 list_for_each_safe(node, next, &resource->reference) { 653 struct acpi_power_reference *ref = container_of(node, struct acpi_power_reference, node); 654 list_del(&ref->node); 655 kfree(ref); 656 } 657 mutex_unlock(&resource->resource_lock); 658 659 kfree(resource); 660 661 return 0; 662 } 663 664 static int acpi_power_resume(struct acpi_device *device) 665 { 666 int result = 0, state; 667 struct acpi_power_resource *resource = NULL; 668 struct acpi_power_reference *ref; 669 670 if (!device || !acpi_driver_data(device)) 671 return -EINVAL; 672 673 resource = (struct acpi_power_resource *)acpi_driver_data(device); 674 675 result = acpi_power_get_state(resource, &state); 676 if (result) 677 return result; 678 679 mutex_lock(&resource->resource_lock); 680 if (state == ACPI_POWER_RESOURCE_STATE_OFF && 681 !list_empty(&resource->reference)) { 682 ref = container_of(resource->reference.next, struct acpi_power_reference, node); 683 mutex_unlock(&resource->resource_lock); 684 result = acpi_power_on(device->handle, ref->device); 685 return result; 686 } 687 688 mutex_unlock(&resource->resource_lock); 689 return 0; 690 } 691 692 static int __init acpi_power_init(void) 693 { 694 int result = 0; 695 696 697 if (acpi_disabled) 698 return 0; 699 700 INIT_LIST_HEAD(&acpi_power_resource_list); 701 702 acpi_power_dir = proc_mkdir(ACPI_POWER_CLASS, acpi_root_dir); 703 if (!acpi_power_dir) 704 return -ENODEV; 705 706 result = acpi_bus_register_driver(&acpi_power_driver); 707 if (result < 0) { 708 remove_proc_entry(ACPI_POWER_CLASS, acpi_root_dir); 709 return -ENODEV; 710 } 711 712 return 0; 713 } 714 715 subsys_initcall(acpi_power_init); 716