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