drivers/acpi/power.c

   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);