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 #include <linux/kernel.h>
  27 #include <linux/module.h>
  28 #include <linux/init.h>
  29 #include <linux/types.h>
  30 #include <linux/compatmac.h>
  31 #include <linux/proc_fs.h>
  32 #include <linux/seq_file.h>
  33 #include "acpi_bus.h"
  34 #include "acpi_drivers.h"
  35
  36
  37 #define _COMPONENT              ACPI_POWER_COMPONENT
  38 ACPI_MODULE_NAME                ("acpi_power")
  39
  40 #define ACPI_POWER_COMPONENT            0x00800000
  41 #define ACPI_POWER_CLASS                "power_resource"
  42 #define ACPI_POWER_DRIVER_NAME          "ACPI Power Resource Driver"
  43 #define ACPI_POWER_DEVICE_NAME          "Power Resource"
  44 #define ACPI_POWER_FILE_INFO            "info"
  45 #define ACPI_POWER_FILE_STATUS          "state"
  46 #define ACPI_POWER_RESOURCE_STATE_OFF   0x00
  47 #define ACPI_POWER_RESOURCE_STATE_ON    0x01
  48 #define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
  49
  50 int acpi_power_add (struct acpi_device *device);
  51 int acpi_power_remove (struct acpi_device *device, int type);
  52 static int acpi_power_open_fs(struct inode *inode, struct file *file);
  53
  54 static struct acpi_driver acpi_power_driver = {
  55         .name =         ACPI_POWER_DRIVER_NAME,
  56         .class =        ACPI_POWER_CLASS,
  57         .ids =          ACPI_POWER_HID,
  58         .ops =          {
  59                                 .add =          acpi_power_add,
  60                                 .remove =       acpi_power_remove,
  61                         },
  62 };
  63
  64 struct acpi_power_resource
  65 {
  66         acpi_handle             handle;
  67         acpi_bus_id             name;
  68         u32                     system_level;
  69         u32                     order;
  70         int                     state;
  71         int                     references;
  72 };
  73
  74 static struct list_head         acpi_power_resource_list;
  75
  76 static struct file_operations acpi_power_fops = {
  77         .open           = acpi_power_open_fs,
  78         .read           = seq_read,
  79         .llseek         = seq_lseek,
  80         .release        = single_release,
  81 };
  82
  83 /* --------------------------------------------------------------------------
  84                              Power Resource Management
  85    -------------------------------------------------------------------------- */
  86
  87 static int
  88 acpi_power_get_context (
  89         acpi_handle             handle,
  90         struct acpi_power_resource **resource)
  91 {
  92         int                     result = 0;
  93         struct acpi_device      *device = NULL;
  94
  95         ACPI_FUNCTION_TRACE("acpi_power_get_context");
  96
  97         if (!resource)
  98                 return_VALUE(-ENODEV);
  99
 100         result = acpi_bus_get_device(handle, &device);
 101         if (result) {
 102                 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Error getting context [%p]\n",
 103                         handle));
 104                 return_VALUE(result);
 105         }
 106
 107         *resource = (struct acpi_power_resource *) acpi_driver_data(device);
 108         if (!resource)
 109                 return_VALUE(-ENODEV);
 110
 111         return_VALUE(0);
 112 }
 113
 114
 115 static int
 116 acpi_power_get_state (
 117         struct acpi_power_resource *resource)
 118 {
 119         acpi_status             status = AE_OK;
 120         unsigned long           sta = 0;
 121
 122         ACPI_FUNCTION_TRACE("acpi_power_get_state");
 123
 124         if (!resource)
 125                 return_VALUE(-EINVAL);
 126
 127         status = acpi_evaluate_integer(resource->handle, "_STA", NULL, &sta);
 128         if (ACPI_FAILURE(status))
 129                 return_VALUE(-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_VALUE(0);
 140 }
 141
 142
 143 static int
 144 acpi_power_get_list_state (
 145         struct acpi_handle_list *list,
 146         int                     *state)
 147 {
 148         int                     result = 0;
 149         struct acpi_power_resource *resource = NULL;
 150         u32                     i = 0;
 151
 152         ACPI_FUNCTION_TRACE("acpi_power_get_list_state");
 153
 154         if (!list || !state)
 155                 return_VALUE(-EINVAL);
 156
 157         /* The state of the list is 'on' IFF all resources are 'on'. */
 158
 159         for (i=0; i<list->count; i++) {
 160                 result = acpi_power_get_context(list->handles[i], &resource);
 161                 if (result)
 162                         return_VALUE(result);
 163                 result = acpi_power_get_state(resource);
 164                 if (result)
 165                         return_VALUE(result);
 166
 167                 *state = resource->state;
 168
 169                 if (*state != ACPI_POWER_RESOURCE_STATE_ON)
 170                         break;
 171         }
 172
 173         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
 174                 *state?"on":"off"));
 175
 176         return_VALUE(result);
 177 }
 178
 179
 180 static int
 181 acpi_power_on (
 182         acpi_handle             handle)
 183 {
 184         int                     result = 0;
 185         acpi_status             status = AE_OK;
 186         struct acpi_device      *device = NULL;
 187         struct acpi_power_resource *resource = NULL;
 188
 189         ACPI_FUNCTION_TRACE("acpi_power_on");
 190
 191         result = acpi_power_get_context(handle, &resource);
 192         if (result)
 193                 return_VALUE(result);
 194
 195         resource->references++;
 196
 197         if ((resource->references > 1)
 198                 || (resource->state == ACPI_POWER_RESOURCE_STATE_ON)) {
 199                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] already on\n",
 200                         resource->name));
 201                 return_VALUE(0);
 202         }
 203
 204         status = acpi_evaluate_object(resource->handle, "_ON", NULL, NULL);
 205         if (ACPI_FAILURE(status))
 206                 return_VALUE(-ENODEV);
 207
 208         result = acpi_power_get_state(resource);
 209         if (result)
 210                 return_VALUE(result);
 211         if (resource->state != ACPI_POWER_RESOURCE_STATE_ON)
 212                 return_VALUE(-ENOEXEC);
 213
 214         /* Update the power resource's _device_ power state */
 215         result = acpi_bus_get_device(resource->handle, &device);
 216         if (result)
 217                 return_VALUE(result);
 218         device->power.state = ACPI_STATE_D0;
 219
 220         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned on\n",
 221                 resource->name));
 222
 223         return_VALUE(0);
 224 }
 225
 226
 227 static int
 228 acpi_power_off_device (
 229         acpi_handle             handle)
 230 {
 231         int                     result = 0;
 232         acpi_status             status = AE_OK;
 233         struct acpi_device      *device = NULL;
 234         struct acpi_power_resource *resource = NULL;
 235
 236         ACPI_FUNCTION_TRACE("acpi_power_off_device");
 237
 238         result = acpi_power_get_context(handle, &resource);
 239         if (result)
 240                 return_VALUE(result);
 241
 242         if (resource->references)
 243                 resource->references--;
 244
 245         if (resource->references) {
 246                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 247                         "Resource [%s] is still in use, dereferencing\n",
 248                         device->pnp.bus_id));
 249                 return_VALUE(0);
 250         }
 251
 252         if (resource->state == ACPI_POWER_RESOURCE_STATE_OFF) {
 253                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] already off\n",
 254                         device->pnp.bus_id));
 255                 return_VALUE(0);
 256         }
 257
 258         status = acpi_evaluate_object(resource->handle, "_OFF", NULL, NULL);
 259         if (ACPI_FAILURE(status))
 260                 return_VALUE(-ENODEV);
 261
 262         result = acpi_power_get_state(resource);
 263         if (result)
 264                 return_VALUE(result);
 265         if (resource->state != ACPI_POWER_RESOURCE_STATE_OFF)
 266                 return_VALUE(-ENOEXEC);
 267
 268         /* Update the power resource's _device_ power state */
 269         result = acpi_bus_get_device(resource->handle, &device);
 270         if (result)
 271                 return_VALUE(result);
 272         device->power.state = ACPI_STATE_D3;
 273
 274         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned off\n",
 275                 resource->name));
 276
 277         return_VALUE(0);
 278 }
 279
 280
 281 /* --------------------------------------------------------------------------
 282                              Device Power Management
 283    -------------------------------------------------------------------------- */
 284
 285 int
 286 acpi_power_get_inferred_state (
 287         struct acpi_device      *device)
 288 {
 289         int                     result = 0;
 290         struct acpi_handle_list *list = NULL;
 291         int                     list_state = 0;
 292         int                     i = 0;
 293
 294         ACPI_FUNCTION_TRACE("acpi_power_get_inferred_state");
 295
 296         if (!device)
 297                 return_VALUE(-EINVAL);
 298
 299         device->power.state = ACPI_STATE_UNKNOWN;
 300
 301         /*
 302          * We know a device's inferred power state when all the resources
 303          * required for a given D-state are 'on'.
 304          */
 305         for (i=ACPI_STATE_D0; i<ACPI_STATE_D3; i++) {
 306                 list = &device->power.states[i].resources;
 307                 if (list->count < 1)
 308                         continue;
 309
 310                 result = acpi_power_get_list_state(list, &list_state);
 311                 if (result)
 312                         return_VALUE(result);
 313
 314                 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
 315                         device->power.state = i;
 316                         return_VALUE(0);
 317                 }
 318         }
 319
 320         device->power.state = ACPI_STATE_D3;
 321
 322         return_VALUE(0);
 323 }
 324
 325
 326 int
 327 acpi_power_transition (
 328         struct acpi_device      *device,
 329         int                     state)
 330 {
 331         int                     result = 0;
 332         struct acpi_handle_list *cl = NULL;     /* Current Resources */
 333         struct acpi_handle_list *tl = NULL;     /* Target Resources */
 334         int                     i = 0;
 335
 336         ACPI_FUNCTION_TRACE("acpi_power_transition");
 337
 338         if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
 339                 return_VALUE(-EINVAL);
 340
 341         cl = &device->power.states[device->power.state].resources;
 342         tl = &device->power.states[state].resources;
 343
 344         device->power.state = ACPI_STATE_UNKNOWN;
 345
 346         if (!cl->count && !tl->count) {
 347                 result = -ENODEV;
 348                 goto end;
 349         }
 350
 351         /* TBD: Resources must be ordered. */
 352
 353         /*
 354          * First we reference all power resources required in the target list
 355          * (e.g. so the device doesn't loose power while transitioning).
 356          */
 357         for (i=0; i<tl->count; i++) {
 358                 result = acpi_power_on(tl->handles[i]);
 359                 if (result)
 360                         goto end;
 361         }
 362
 363         device->power.state = state;
 364
 365         /*
 366          * Then we dereference all power resources used in the current list.
 367          */
 368         for (i=0; i<cl->count; i++) {
 369                 result = acpi_power_off_device(cl->handles[i]);
 370                 if (result)
 371                         goto end;
 372         }
 373
 374 end:
 375         if (result)
 376                 ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 377                         "Error transitioning device [%s] to D%d\n",
 378                         device->pnp.bus_id, state));
 379
 380         return_VALUE(result);
 381 }
 382
 383
 384 /* --------------------------------------------------------------------------
 385                               FS Interface (/proc)
 386    -------------------------------------------------------------------------- */
 387
 388 struct proc_dir_entry           *acpi_power_dir = NULL;
 389
 390 static int acpi_power_seq_show(struct seq_file *seq, void *offset)
 391 {
 392         struct acpi_power_resource *resource = NULL;
 393
 394         ACPI_FUNCTION_TRACE("acpi_power_seq_show");
 395
 396         resource = (struct acpi_power_resource *)seq->private;
 397
 398         if (!resource)
 399                 goto end;
 400
 401         seq_puts(seq, "state:                   ");
 402         switch (resource->state) {
 403         case ACPI_POWER_RESOURCE_STATE_ON:
 404                 seq_puts(seq, "on\n");
 405                 break;
 406         case ACPI_POWER_RESOURCE_STATE_OFF:
 407                 seq_puts(seq, "off\n");
 408                 break;
 409         default:
 410                 seq_puts(seq, "unknown\n");
 411                 break;
 412         }
 413
 414         seq_printf(seq, "system level:            S%d\n"
 415                         "order:                   %d\n"
 416                         "reference count:         %d\n",
 417                         resource->system_level,
 418                         resource->order,
 419                         resource->references);
 420
 421 end:
 422         return 0;
 423 }
 424
 425 static int acpi_power_open_fs(struct inode *inode, struct file *file)
 426 {
 427         return single_open(file, acpi_power_seq_show, PDE(inode)->data);
 428 }
 429
 430 static int
 431 acpi_power_add_fs (
 432         struct acpi_device      *device)
 433 {
 434         struct proc_dir_entry   *entry = NULL;
 435
 436         ACPI_FUNCTION_TRACE("acpi_power_add_fs");
 437
 438         if (!device)
 439                 return_VALUE(-EINVAL);
 440
 441         if (!acpi_device_dir(device)) {
 442                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 443                         acpi_power_dir);
 444                 if (!acpi_device_dir(device))
 445                         return_VALUE(-ENODEV);
 446         }
 447
 448         /* 'status' [R] */
 449         entry = create_proc_entry(ACPI_POWER_FILE_STATUS,
 450                 S_IRUGO, acpi_device_dir(device));
 451         if (!entry)
 452                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 453                         "Unable to create '%s' fs entry\n",
 454                         ACPI_POWER_FILE_STATUS));
 455         else {
 456                 entry->proc_fops = &acpi_power_fops;
 457                 entry->data = acpi_driver_data(device);
 458         }
 459
 460         return_VALUE(0);
 461 }
 462
 463
 464 static int
 465 acpi_power_remove_fs (
 466         struct acpi_device      *device)
 467 {
 468         ACPI_FUNCTION_TRACE("acpi_power_remove_fs");
 469
 470         if (acpi_device_dir(device)) {
 471                 remove_proc_entry(acpi_device_bid(device), acpi_power_dir);
 472                 acpi_device_dir(device) = NULL;
 473         }
 474
 475         return_VALUE(0);
 476 }
 477
 478
 479 /* --------------------------------------------------------------------------
 480                                 Driver Interface
 481    -------------------------------------------------------------------------- */
 482
 483 int
 484 acpi_power_add (
 485         struct acpi_device      *device)
 486 {
 487         int                     result = 0;
 488         acpi_status             status = AE_OK;
 489         struct acpi_power_resource *resource = NULL;
 490         union acpi_object       acpi_object;
 491         struct acpi_buffer      buffer = {sizeof(acpi_object), &acpi_object};
 492
 493         ACPI_FUNCTION_TRACE("acpi_power_add");
 494
 495         if (!device)
 496                 return_VALUE(-EINVAL);
 497
 498         resource = kmalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
 499         if (!resource)
 500                 return_VALUE(-ENOMEM);
 501         memset(resource, 0, sizeof(struct acpi_power_resource));
 502
 503         resource->handle = device->handle;
 504         sprintf(resource->name, "%s", device->pnp.bus_id);
 505         sprintf(acpi_device_name(device), "%s", ACPI_POWER_DEVICE_NAME);
 506         sprintf(acpi_device_class(device), "%s", ACPI_POWER_CLASS);
 507         acpi_driver_data(device) = resource;
 508
 509         /* Evalute the object to get the system level and resource order. */
 510         status = acpi_evaluate_object(resource->handle, NULL, NULL, &buffer);
 511         if (ACPI_FAILURE(status)) {
 512                 result = -ENODEV;
 513                 goto end;
 514         }
 515         resource->system_level = acpi_object.power_resource.system_level;
 516         resource->order = acpi_object.power_resource.resource_order;
 517
 518         result = acpi_power_get_state(resource);
 519         if (result)
 520                 goto end;
 521
 522         switch (resource->state) {
 523         case ACPI_POWER_RESOURCE_STATE_ON:
 524                 device->power.state = ACPI_STATE_D0;
 525                 break;
 526         case ACPI_POWER_RESOURCE_STATE_OFF:
 527                 device->power.state = ACPI_STATE_D3;
 528                 break;
 529         default:
 530                 device->power.state = ACPI_STATE_UNKNOWN;
 531                 break;
 532         }
 533
 534         result = acpi_power_add_fs(device);
 535         if (result)
 536                 goto end;
 537
 538         printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
 539                 acpi_device_bid(device), resource->state?"on":"off");
 540
 541 end:
 542         if (result)
 543                 kfree(resource);
 544
 545         return_VALUE(result);
 546 }
 547
 548
 549 int
 550 acpi_power_remove (
 551         struct acpi_device      *device,
 552         int                     type)
 553 {
 554         struct acpi_power_resource *resource = NULL;
 555
 556         ACPI_FUNCTION_TRACE("acpi_power_remove");
 557
 558         if (!device || !acpi_driver_data(device))
 559                 return_VALUE(-EINVAL);
 560
 561         resource = (struct acpi_power_resource *) acpi_driver_data(device);
 562
 563         acpi_power_remove_fs(device);
 564
 565         kfree(resource);
 566
 567         return_VALUE(0);
 568 }
 569
 570
 571 static int __init acpi_power_init (void)
 572 {
 573         int                     result = 0;
 574
 575         ACPI_FUNCTION_TRACE("acpi_power_init");
 576
 577         if (acpi_disabled)
 578                 return_VALUE(0);
 579
 580         INIT_LIST_HEAD(&acpi_power_resource_list);
 581
 582         acpi_power_dir = proc_mkdir(ACPI_POWER_CLASS, acpi_root_dir);
 583         if (!acpi_power_dir)
 584                 return_VALUE(-ENODEV);
 585
 586         result = acpi_bus_register_driver(&acpi_power_driver);
 587         if (result < 0) {
 588                 remove_proc_entry(ACPI_POWER_CLASS, acpi_root_dir);
 589                 return_VALUE(-ENODEV);
 590         }
 591
 592         return_VALUE(0);
 593 }
 594
 595 subsys_initcall(acpi_power_init);
 596