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("acpi_power") 49 #define ACPI_POWER_COMPONENT 0x00800000 50 #define ACPI_POWER_CLASS "power_resource" 51 #define ACPI_POWER_DRIVER_NAME "ACPI Power Resource Driver" 52 #define ACPI_POWER_DEVICE_NAME "Power Resource" 53 #define ACPI_POWER_FILE_INFO "info" 54 #define ACPI_POWER_FILE_STATUS "state" 55 #define ACPI_POWER_RESOURCE_STATE_OFF 0x00 56 #define ACPI_POWER_RESOURCE_STATE_ON 0x01 57 #define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF 58 static int acpi_power_add(struct acpi_device *device); 59 static int acpi_power_remove(struct acpi_device *device, int type); 60 static int acpi_power_open_fs(struct inode *inode, struct file *file); 61 62 static struct acpi_driver acpi_power_driver = { 63 .name = ACPI_POWER_DRIVER_NAME, 64 .class = ACPI_POWER_CLASS, 65 .ids = ACPI_POWER_HID, 66 .ops = { 67 .add = acpi_power_add, 68 .remove = acpi_power_remove, 69 }, 70 }; 71 72 struct acpi_power_resource { 73 acpi_handle handle; 74 acpi_bus_id name; 75 u32 system_level; 76 u32 order; 77 int state; 78 int references; 79 }; 80 81 static struct list_head acpi_power_resource_list; 82 83 static struct file_operations acpi_power_fops = { 84 .open = acpi_power_open_fs, 85 .read = seq_read, 86 .llseek = seq_lseek, 87 .release = single_release, 88 }; 89 90 /* -------------------------------------------------------------------------- 91 Power Resource Management 92 -------------------------------------------------------------------------- */ 93 94 static int 95 acpi_power_get_context(acpi_handle handle, 96 struct acpi_power_resource **resource) 97 { 98 int result = 0; 99 struct acpi_device *device = NULL; 100 101 ACPI_FUNCTION_TRACE("acpi_power_get_context"); 102 103 if (!resource) 104 return_VALUE(-ENODEV); 105 106 result = acpi_bus_get_device(handle, &device); 107 if (result) { 108 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Error getting context [%p]\n", 109 handle)); 110 return_VALUE(result); 111 } 112 113 *resource = (struct acpi_power_resource *)acpi_driver_data(device); 114 if (!resource) 115 return_VALUE(-ENODEV); 116 117 return_VALUE(0); 118 } 119 120 static int acpi_power_get_state(struct acpi_power_resource *resource) 121 { 122 acpi_status status = AE_OK; 123 unsigned long sta = 0; 124 125 ACPI_FUNCTION_TRACE("acpi_power_get_state"); 126 127 if (!resource) 128 return_VALUE(-EINVAL); 129 130 status = acpi_evaluate_integer(resource->handle, "_STA", NULL, &sta); 131 if (ACPI_FAILURE(status)) 132 return_VALUE(-ENODEV); 133 134 if (sta & 0x01) 135 resource->state = ACPI_POWER_RESOURCE_STATE_ON; 136 else 137 resource->state = ACPI_POWER_RESOURCE_STATE_OFF; 138 139 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n", 140 resource->name, resource->state ? "on" : "off")); 141 142 return_VALUE(0); 143 } 144 145 static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state) 146 { 147 int result = 0; 148 struct acpi_power_resource *resource = NULL; 149 u32 i = 0; 150 151 ACPI_FUNCTION_TRACE("acpi_power_get_list_state"); 152 153 if (!list || !state) 154 return_VALUE(-EINVAL); 155 156 /* The state of the list is 'on' IFF all resources are 'on'. */ 157 158 for (i = 0; i < list->count; i++) { 159 result = acpi_power_get_context(list->handles[i], &resource); 160 if (result) 161 return_VALUE(result); 162 result = acpi_power_get_state(resource); 163 if (result) 164 return_VALUE(result); 165 166 *state = resource->state; 167 168 if (*state != ACPI_POWER_RESOURCE_STATE_ON) 169 break; 170 } 171 172 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n", 173 *state ? "on" : "off")); 174 175 return_VALUE(result); 176 } 177 178 static int acpi_power_on(acpi_handle handle) 179 { 180 int result = 0; 181 acpi_status status = AE_OK; 182 struct acpi_device *device = NULL; 183 struct acpi_power_resource *resource = NULL; 184 185 ACPI_FUNCTION_TRACE("acpi_power_on"); 186 187 result = acpi_power_get_context(handle, &resource); 188 if (result) 189 return_VALUE(result); 190 191 resource->references++; 192 193 if ((resource->references > 1) 194 || (resource->state == ACPI_POWER_RESOURCE_STATE_ON)) { 195 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] already on\n", 196 resource->name)); 197 return_VALUE(0); 198 } 199 200 status = acpi_evaluate_object(resource->handle, "_ON", NULL, NULL); 201 if (ACPI_FAILURE(status)) 202 return_VALUE(-ENODEV); 203 204 result = acpi_power_get_state(resource); 205 if (result) 206 return_VALUE(result); 207 if (resource->state != ACPI_POWER_RESOURCE_STATE_ON) 208 return_VALUE(-ENOEXEC); 209 210 /* Update the power resource's _device_ power state */ 211 result = acpi_bus_get_device(resource->handle, &device); 212 if (result) 213 return_VALUE(result); 214 device->power.state = ACPI_STATE_D0; 215 216 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned on\n", 217 resource->name)); 218 219 return_VALUE(0); 220 } 221 222 static int acpi_power_off_device(acpi_handle handle) 223 { 224 int result = 0; 225 acpi_status status = AE_OK; 226 struct acpi_device *device = NULL; 227 struct acpi_power_resource *resource = NULL; 228 229 ACPI_FUNCTION_TRACE("acpi_power_off_device"); 230 231 result = acpi_power_get_context(handle, &resource); 232 if (result) 233 return_VALUE(result); 234 235 if (resource->references) 236 resource->references--; 237 238 if (resource->references) { 239 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 240 "Resource [%s] is still in use, dereferencing\n", 241 device->pnp.bus_id)); 242 return_VALUE(0); 243 } 244 245 if (resource->state == ACPI_POWER_RESOURCE_STATE_OFF) { 246 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] already off\n", 247 device->pnp.bus_id)); 248 return_VALUE(0); 249 } 250 251 status = acpi_evaluate_object(resource->handle, "_OFF", NULL, NULL); 252 if (ACPI_FAILURE(status)) 253 return_VALUE(-ENODEV); 254 255 result = acpi_power_get_state(resource); 256 if (result) 257 return_VALUE(result); 258 if (resource->state != ACPI_POWER_RESOURCE_STATE_OFF) 259 return_VALUE(-ENOEXEC); 260 261 /* Update the power resource's _device_ power state */ 262 result = acpi_bus_get_device(resource->handle, &device); 263 if (result) 264 return_VALUE(result); 265 device->power.state = ACPI_STATE_D3; 266 267 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned off\n", 268 resource->name)); 269 270 return_VALUE(0); 271 } 272 273 /* 274 * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229): 275 * 1. Power on the power resources required for the wakeup device 276 * 2. Enable _PSW (power state wake) for the device if present 277 */ 278 int acpi_enable_wakeup_device_power(struct acpi_device *dev) 279 { 280 union acpi_object arg = { ACPI_TYPE_INTEGER }; 281 struct acpi_object_list arg_list = { 1, &arg }; 282 acpi_status status = AE_OK; 283 int i; 284 int ret = 0; 285 286 ACPI_FUNCTION_TRACE("acpi_enable_wakeup_device_power"); 287 if (!dev || !dev->wakeup.flags.valid) 288 return_VALUE(-1); 289 290 arg.integer.value = 1; 291 /* Open power resource */ 292 for (i = 0; i < dev->wakeup.resources.count; i++) { 293 ret = acpi_power_on(dev->wakeup.resources.handles[i]); 294 if (ret) { 295 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 296 "Error transition power state\n")); 297 dev->wakeup.flags.valid = 0; 298 return_VALUE(-1); 299 } 300 } 301 302 /* Execute PSW */ 303 status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL); 304 if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) { 305 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluate _PSW\n")); 306 dev->wakeup.flags.valid = 0; 307 ret = -1; 308 } 309 310 return_VALUE(ret); 311 } 312 313 /* 314 * Shutdown a wakeup device, counterpart of above method 315 * 1. Disable _PSW (power state wake) 316 * 2. Shutdown down the power resources 317 */ 318 int acpi_disable_wakeup_device_power(struct acpi_device *dev) 319 { 320 union acpi_object arg = { ACPI_TYPE_INTEGER }; 321 struct acpi_object_list arg_list = { 1, &arg }; 322 acpi_status status = AE_OK; 323 int i; 324 int ret = 0; 325 326 ACPI_FUNCTION_TRACE("acpi_disable_wakeup_device_power"); 327 328 if (!dev || !dev->wakeup.flags.valid) 329 return_VALUE(-1); 330 331 arg.integer.value = 0; 332 /* Execute PSW */ 333 status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL); 334 if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) { 335 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluate _PSW\n")); 336 dev->wakeup.flags.valid = 0; 337 return_VALUE(-1); 338 } 339 340 /* Close power resource */ 341 for (i = 0; i < dev->wakeup.resources.count; i++) { 342 ret = acpi_power_off_device(dev->wakeup.resources.handles[i]); 343 if (ret) { 344 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 345 "Error transition power state\n")); 346 dev->wakeup.flags.valid = 0; 347 return_VALUE(-1); 348 } 349 } 350 351 return_VALUE(ret); 352 } 353 354 /* -------------------------------------------------------------------------- 355 Device Power Management 356 -------------------------------------------------------------------------- */ 357 358 int acpi_power_get_inferred_state(struct acpi_device *device) 359 { 360 int result = 0; 361 struct acpi_handle_list *list = NULL; 362 int list_state = 0; 363 int i = 0; 364 365 ACPI_FUNCTION_TRACE("acpi_power_get_inferred_state"); 366 367 if (!device) 368 return_VALUE(-EINVAL); 369 370 device->power.state = ACPI_STATE_UNKNOWN; 371 372 /* 373 * We know a device's inferred power state when all the resources 374 * required for a given D-state are 'on'. 375 */ 376 for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) { 377 list = &device->power.states[i].resources; 378 if (list->count < 1) 379 continue; 380 381 result = acpi_power_get_list_state(list, &list_state); 382 if (result) 383 return_VALUE(result); 384 385 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) { 386 device->power.state = i; 387 return_VALUE(0); 388 } 389 } 390 391 device->power.state = ACPI_STATE_D3; 392 393 return_VALUE(0); 394 } 395 396 int acpi_power_transition(struct acpi_device *device, int state) 397 { 398 int result = 0; 399 struct acpi_handle_list *cl = NULL; /* Current Resources */ 400 struct acpi_handle_list *tl = NULL; /* Target Resources */ 401 int i = 0; 402 403 ACPI_FUNCTION_TRACE("acpi_power_transition"); 404 405 if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3)) 406 return_VALUE(-EINVAL); 407 408 if ((device->power.state < ACPI_STATE_D0) 409 || (device->power.state > ACPI_STATE_D3)) 410 return_VALUE(-ENODEV); 411 412 cl = &device->power.states[device->power.state].resources; 413 tl = &device->power.states[state].resources; 414 415 device->power.state = ACPI_STATE_UNKNOWN; 416 417 if (!cl->count && !tl->count) { 418 result = -ENODEV; 419 goto end; 420 } 421 422 /* TBD: Resources must be ordered. */ 423 424 /* 425 * First we reference all power resources required in the target list 426 * (e.g. so the device doesn't lose power while transitioning). 427 */ 428 for (i = 0; i < tl->count; i++) { 429 result = acpi_power_on(tl->handles[i]); 430 if (result) 431 goto end; 432 } 433 434 /* 435 * Then we dereference all power resources used in the current list. 436 */ 437 for (i = 0; i < cl->count; i++) { 438 result = acpi_power_off_device(cl->handles[i]); 439 if (result) 440 goto end; 441 } 442 443 /* We shouldn't change the state till all above operations succeed */ 444 device->power.state = state; 445 end: 446 if (result) 447 ACPI_DEBUG_PRINT((ACPI_DB_WARN, 448 "Error transitioning device [%s] to D%d\n", 449 device->pnp.bus_id, state)); 450 451 return_VALUE(result); 452 } 453 454 /* -------------------------------------------------------------------------- 455 FS Interface (/proc) 456 -------------------------------------------------------------------------- */ 457 458 static struct proc_dir_entry *acpi_power_dir; 459 460 static int acpi_power_seq_show(struct seq_file *seq, void *offset) 461 { 462 struct acpi_power_resource *resource = NULL; 463 464 ACPI_FUNCTION_TRACE("acpi_power_seq_show"); 465 466 resource = (struct acpi_power_resource *)seq->private; 467 468 if (!resource) 469 goto end; 470 471 seq_puts(seq, "state: "); 472 switch (resource->state) { 473 case ACPI_POWER_RESOURCE_STATE_ON: 474 seq_puts(seq, "on\n"); 475 break; 476 case ACPI_POWER_RESOURCE_STATE_OFF: 477 seq_puts(seq, "off\n"); 478 break; 479 default: 480 seq_puts(seq, "unknown\n"); 481 break; 482 } 483 484 seq_printf(seq, "system level: S%d\n" 485 "order: %d\n" 486 "reference count: %d\n", 487 resource->system_level, 488 resource->order, resource->references); 489 490 end: 491 return_VALUE(0); 492 } 493 494 static int acpi_power_open_fs(struct inode *inode, struct file *file) 495 { 496 return single_open(file, acpi_power_seq_show, PDE(inode)->data); 497 } 498 499 static int acpi_power_add_fs(struct acpi_device *device) 500 { 501 struct proc_dir_entry *entry = NULL; 502 503 ACPI_FUNCTION_TRACE("acpi_power_add_fs"); 504 505 if (!device) 506 return_VALUE(-EINVAL); 507 508 if (!acpi_device_dir(device)) { 509 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device), 510 acpi_power_dir); 511 if (!acpi_device_dir(device)) 512 return_VALUE(-ENODEV); 513 } 514 515 /* 'status' [R] */ 516 entry = create_proc_entry(ACPI_POWER_FILE_STATUS, 517 S_IRUGO, acpi_device_dir(device)); 518 if (!entry) 519 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 520 "Unable to create '%s' fs entry\n", 521 ACPI_POWER_FILE_STATUS)); 522 else { 523 entry->proc_fops = &acpi_power_fops; 524 entry->data = acpi_driver_data(device); 525 } 526 527 return_VALUE(0); 528 } 529 530 static int acpi_power_remove_fs(struct acpi_device *device) 531 { 532 ACPI_FUNCTION_TRACE("acpi_power_remove_fs"); 533 534 if (acpi_device_dir(device)) { 535 remove_proc_entry(ACPI_POWER_FILE_STATUS, 536 acpi_device_dir(device)); 537 remove_proc_entry(acpi_device_bid(device), acpi_power_dir); 538 acpi_device_dir(device) = NULL; 539 } 540 541 return_VALUE(0); 542 } 543 544 /* -------------------------------------------------------------------------- 545 Driver Interface 546 -------------------------------------------------------------------------- */ 547 548 static int acpi_power_add(struct acpi_device *device) 549 { 550 int result = 0; 551 acpi_status status = AE_OK; 552 struct acpi_power_resource *resource = NULL; 553 union acpi_object acpi_object; 554 struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object }; 555 556 ACPI_FUNCTION_TRACE("acpi_power_add"); 557 558 if (!device) 559 return_VALUE(-EINVAL); 560 561 resource = kmalloc(sizeof(struct acpi_power_resource), GFP_KERNEL); 562 if (!resource) 563 return_VALUE(-ENOMEM); 564 memset(resource, 0, sizeof(struct acpi_power_resource)); 565 566 resource->handle = device->handle; 567 strcpy(resource->name, device->pnp.bus_id); 568 strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME); 569 strcpy(acpi_device_class(device), ACPI_POWER_CLASS); 570 acpi_driver_data(device) = resource; 571 572 /* Evalute the object to get the system level and resource order. */ 573 status = acpi_evaluate_object(resource->handle, NULL, NULL, &buffer); 574 if (ACPI_FAILURE(status)) { 575 result = -ENODEV; 576 goto end; 577 } 578 resource->system_level = acpi_object.power_resource.system_level; 579 resource->order = acpi_object.power_resource.resource_order; 580 581 result = acpi_power_get_state(resource); 582 if (result) 583 goto end; 584 585 switch (resource->state) { 586 case ACPI_POWER_RESOURCE_STATE_ON: 587 device->power.state = ACPI_STATE_D0; 588 break; 589 case ACPI_POWER_RESOURCE_STATE_OFF: 590 device->power.state = ACPI_STATE_D3; 591 break; 592 default: 593 device->power.state = ACPI_STATE_UNKNOWN; 594 break; 595 } 596 597 result = acpi_power_add_fs(device); 598 if (result) 599 goto end; 600 601 printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device), 602 acpi_device_bid(device), resource->state ? "on" : "off"); 603 604 end: 605 if (result) 606 kfree(resource); 607 608 return_VALUE(result); 609 } 610 611 static int acpi_power_remove(struct acpi_device *device, int type) 612 { 613 struct acpi_power_resource *resource = NULL; 614 615 ACPI_FUNCTION_TRACE("acpi_power_remove"); 616 617 if (!device || !acpi_driver_data(device)) 618 return_VALUE(-EINVAL); 619 620 resource = (struct acpi_power_resource *)acpi_driver_data(device); 621 622 acpi_power_remove_fs(device); 623 624 kfree(resource); 625 626 return_VALUE(0); 627 } 628 629 static int __init acpi_power_init(void) 630 { 631 int result = 0; 632 633 ACPI_FUNCTION_TRACE("acpi_power_init"); 634 635 if (acpi_disabled) 636 return_VALUE(0); 637 638 INIT_LIST_HEAD(&acpi_power_resource_list); 639 640 acpi_power_dir = proc_mkdir(ACPI_POWER_CLASS, acpi_root_dir); 641 if (!acpi_power_dir) 642 return_VALUE(-ENODEV); 643 644 result = acpi_bus_register_driver(&acpi_power_driver); 645 if (result < 0) { 646 remove_proc_entry(ACPI_POWER_CLASS, acpi_root_dir); 647 return_VALUE(-ENODEV); 648 } 649 650 return_VALUE(0); 651 } 652 653 subsys_initcall(acpi_power_init); 654