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