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
 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->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->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         result = acpi_bus_get_device(resource->handle, &device);
 207         if (result)
 208                 return result;
 209         device->power.state = ACPI_STATE_D0;
 210
 211         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned on\n",
 212                           resource->name));
 213
 214         return 0;
 215 }
 216
 217 static int acpi_power_off_device(acpi_handle handle)
 218 {
 219         int result = 0;
 220         acpi_status status = AE_OK;
 221         struct acpi_device *device = NULL;
 222         struct acpi_power_resource *resource = NULL;
 223
 224
 225         result = acpi_power_get_context(handle, &resource);
 226         if (result)
 227                 return result;
 228
 229         if (resource->references)
 230                 resource->references--;
 231
 232         if (resource->references) {
 233                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 234                                   "Resource [%s] is still in use, dereferencing\n",
 235                                   device->pnp.bus_id));
 236                 return 0;
 237         }
 238
 239         if (resource->state == ACPI_POWER_RESOURCE_STATE_OFF) {
 240                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] already off\n",
 241                                   device->pnp.bus_id));
 242                 return 0;
 243         }
 244
 245         status = acpi_evaluate_object(resource->handle, "_OFF", NULL, NULL);
 246         if (ACPI_FAILURE(status))
 247                 return -ENODEV;
 248
 249         result = acpi_power_get_state(resource);
 250         if (result)
 251                 return result;
 252         if (resource->state != ACPI_POWER_RESOURCE_STATE_OFF)
 253                 return -ENOEXEC;
 254
 255         /* Update the power resource's _device_ power state */
 256         result = acpi_bus_get_device(resource->handle, &device);
 257         if (result)
 258                 return result;
 259         device->power.state = ACPI_STATE_D3;
 260
 261         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned off\n",
 262                           resource->name));
 263
 264         return 0;
 265 }
 266
 267 /*
 268  * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
 269  * 1. Power on the power resources required for the wakeup device
 270  * 2. Enable _PSW (power state wake) for the device if present
 271  */
 272 int acpi_enable_wakeup_device_power(struct acpi_device *dev)
 273 {
 274         union acpi_object arg = { ACPI_TYPE_INTEGER };
 275         struct acpi_object_list arg_list = { 1, &arg };
 276         acpi_status status = AE_OK;
 277         int i;
 278         int ret = 0;
 279
 280         if (!dev || !dev->wakeup.flags.valid)
 281                 return -1;
 282
 283         arg.integer.value = 1;
 284         /* Open power resource */
 285         for (i = 0; i < dev->wakeup.resources.count; i++) {
 286                 ret = acpi_power_on(dev->wakeup.resources.handles[i]);
 287                 if (ret) {
 288                         printk(KERN_ERR PREFIX "Transition power state\n");
 289                         dev->wakeup.flags.valid = 0;
 290                         return -1;
 291                 }
 292         }
 293
 294         /* Execute PSW */
 295         status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
 296         if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
 297                 printk(KERN_ERR PREFIX "Evaluate _PSW\n");
 298                 dev->wakeup.flags.valid = 0;
 299                 ret = -1;
 300         }
 301
 302         return ret;
 303 }
 304
 305 /*
 306  * Shutdown a wakeup device, counterpart of above method
 307  * 1. Disable _PSW (power state wake)
 308  * 2. Shutdown down the power resources
 309  */
 310 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
 311 {
 312         union acpi_object arg = { ACPI_TYPE_INTEGER };
 313         struct acpi_object_list arg_list = { 1, &arg };
 314         acpi_status status = AE_OK;
 315         int i;
 316         int ret = 0;
 317
 318
 319         if (!dev || !dev->wakeup.flags.valid)
 320                 return -1;
 321
 322         arg.integer.value = 0;
 323         /* Execute PSW */
 324         status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
 325         if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
 326                 printk(KERN_ERR PREFIX "Evaluate _PSW\n");
 327                 dev->wakeup.flags.valid = 0;
 328                 return -1;
 329         }
 330
 331         /* Close power resource */
 332         for (i = 0; i < dev->wakeup.resources.count; i++) {
 333                 ret = acpi_power_off_device(dev->wakeup.resources.handles[i]);
 334                 if (ret) {
 335                         printk(KERN_ERR PREFIX "Transition power state\n");
 336                         dev->wakeup.flags.valid = 0;
 337                         return -1;
 338                 }
 339         }
 340
 341         return ret;
 342 }
 343
 344 /* --------------------------------------------------------------------------
 345                              Device Power Management
 346    -------------------------------------------------------------------------- */
 347
 348 int acpi_power_get_inferred_state(struct acpi_device *device)
 349 {
 350         int result = 0;
 351         struct acpi_handle_list *list = NULL;
 352         int list_state = 0;
 353         int i = 0;
 354
 355
 356         if (!device)
 357                 return -EINVAL;
 358
 359         device->power.state = ACPI_STATE_UNKNOWN;
 360
 361         /*
 362          * We know a device's inferred power state when all the resources
 363          * required for a given D-state are 'on'.
 364          */
 365         for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) {
 366                 list = &device->power.states[i].resources;
 367                 if (list->count < 1)
 368                         continue;
 369
 370                 result = acpi_power_get_list_state(list, &list_state);
 371                 if (result)
 372                         return result;
 373
 374                 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
 375                         device->power.state = i;
 376                         return 0;
 377                 }
 378         }
 379
 380         device->power.state = ACPI_STATE_D3;
 381
 382         return 0;
 383 }
 384
 385 int acpi_power_transition(struct acpi_device *device, int state)
 386 {
 387         int result = 0;
 388         struct acpi_handle_list *cl = NULL;     /* Current Resources */
 389         struct acpi_handle_list *tl = NULL;     /* Target Resources */
 390         int i = 0;
 391
 392
 393         if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
 394                 return -EINVAL;
 395
 396         if ((device->power.state < ACPI_STATE_D0)
 397             || (device->power.state > ACPI_STATE_D3))
 398                 return -ENODEV;
 399
 400         cl = &device->power.states[device->power.state].resources;
 401         tl = &device->power.states[state].resources;
 402
 403         device->power.state = ACPI_STATE_UNKNOWN;
 404
 405         if (!cl->count && !tl->count) {
 406                 result = -ENODEV;
 407                 goto end;
 408         }
 409
 410         /* TBD: Resources must be ordered. */
 411
 412         /*
 413          * First we reference all power resources required in the target list
 414          * (e.g. so the device doesn't lose power while transitioning).
 415          */
 416         for (i = 0; i < tl->count; i++) {
 417                 result = acpi_power_on(tl->handles[i]);
 418                 if (result)
 419                         goto end;
 420         }
 421
 422         /*
 423          * Then we dereference all power resources used in the current list.
 424          */
 425         for (i = 0; i < cl->count; i++) {
 426                 result = acpi_power_off_device(cl->handles[i]);
 427                 if (result)
 428                         goto end;
 429         }
 430
 431         /* We shouldn't change the state till all above operations succeed */
 432         device->power.state = state;
 433       end:
 434         if (result)
 435                 printk(KERN_WARNING PREFIX "Transitioning device [%s] to D%d\n",
 436                               device->pnp.bus_id, state);
 437
 438         return result;
 439 }
 440
 441 /* --------------------------------------------------------------------------
 442                               FS Interface (/proc)
 443    -------------------------------------------------------------------------- */
 444
 445 static struct proc_dir_entry *acpi_power_dir;
 446
 447 static int acpi_power_seq_show(struct seq_file *seq, void *offset)
 448 {
 449         struct acpi_power_resource *resource = NULL;
 450
 451
 452         resource = (struct acpi_power_resource *)seq->private;
 453
 454         if (!resource)
 455                 goto end;
 456
 457         seq_puts(seq, "state:                   ");
 458         switch (resource->state) {
 459         case ACPI_POWER_RESOURCE_STATE_ON:
 460                 seq_puts(seq, "on\n");
 461                 break;
 462         case ACPI_POWER_RESOURCE_STATE_OFF:
 463                 seq_puts(seq, "off\n");
 464                 break;
 465         default:
 466                 seq_puts(seq, "unknown\n");
 467                 break;
 468         }
 469
 470         seq_printf(seq, "system level:            S%d\n"
 471                    "order:                   %d\n"
 472                    "reference count:         %d\n",
 473                    resource->system_level,
 474                    resource->order, resource->references);
 475
 476       end:
 477         return 0;
 478 }
 479
 480 static int acpi_power_open_fs(struct inode *inode, struct file *file)
 481 {
 482         return single_open(file, acpi_power_seq_show, PDE(inode)->data);
 483 }
 484
 485 static int acpi_power_add_fs(struct acpi_device *device)
 486 {
 487         struct proc_dir_entry *entry = NULL;
 488
 489
 490         if (!device)
 491                 return -EINVAL;
 492
 493         if (!acpi_device_dir(device)) {
 494                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 495                                                      acpi_power_dir);
 496                 if (!acpi_device_dir(device))
 497                         return -ENODEV;
 498         }
 499
 500         /* 'status' [R] */
 501         entry = create_proc_entry(ACPI_POWER_FILE_STATUS,
 502                                   S_IRUGO, acpi_device_dir(device));
 503         if (!entry)
 504                 return -EIO;
 505         else {
 506                 entry->proc_fops = &acpi_power_fops;
 507                 entry->data = acpi_driver_data(device);
 508         }
 509
 510         return 0;
 511 }
 512
 513 static int acpi_power_remove_fs(struct acpi_device *device)
 514 {
 515
 516         if (acpi_device_dir(device)) {
 517                 remove_proc_entry(ACPI_POWER_FILE_STATUS,
 518                                   acpi_device_dir(device));
 519                 remove_proc_entry(acpi_device_bid(device), acpi_power_dir);
 520                 acpi_device_dir(device) = NULL;
 521         }
 522
 523         return 0;
 524 }
 525
 526 /* --------------------------------------------------------------------------
 527                                 Driver Interface
 528    -------------------------------------------------------------------------- */
 529
 530 static int acpi_power_add(struct acpi_device *device)
 531 {
 532         int result = 0;
 533         acpi_status status = AE_OK;
 534         struct acpi_power_resource *resource = NULL;
 535         union acpi_object acpi_object;
 536         struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
 537
 538
 539         if (!device)
 540                 return -EINVAL;
 541
 542         resource = kmalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
 543         if (!resource)
 544                 return -ENOMEM;
 545         memset(resource, 0, sizeof(struct acpi_power_resource));
 546
 547         resource->handle = device->handle;
 548         strcpy(resource->name, device->pnp.bus_id);
 549         strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
 550         strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
 551         acpi_driver_data(device) = resource;
 552
 553         /* Evalute the object to get the system level and resource order. */
 554         status = acpi_evaluate_object(resource->handle, NULL, NULL, &buffer);
 555         if (ACPI_FAILURE(status)) {
 556                 result = -ENODEV;
 557                 goto end;
 558         }
 559         resource->system_level = acpi_object.power_resource.system_level;
 560         resource->order = acpi_object.power_resource.resource_order;
 561
 562         result = acpi_power_get_state(resource);
 563         if (result)
 564                 goto end;
 565
 566         switch (resource->state) {
 567         case ACPI_POWER_RESOURCE_STATE_ON:
 568                 device->power.state = ACPI_STATE_D0;
 569                 break;
 570         case ACPI_POWER_RESOURCE_STATE_OFF:
 571                 device->power.state = ACPI_STATE_D3;
 572                 break;
 573         default:
 574                 device->power.state = ACPI_STATE_UNKNOWN;
 575                 break;
 576         }
 577
 578         result = acpi_power_add_fs(device);
 579         if (result)
 580                 goto end;
 581
 582         printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
 583                acpi_device_bid(device), resource->state ? "on" : "off");
 584
 585       end:
 586         if (result)
 587                 kfree(resource);
 588
 589         return result;
 590 }
 591
 592 static int acpi_power_remove(struct acpi_device *device, int type)
 593 {
 594         struct acpi_power_resource *resource = NULL;
 595
 596
 597         if (!device || !acpi_driver_data(device))
 598                 return -EINVAL;
 599
 600         resource = (struct acpi_power_resource *)acpi_driver_data(device);
 601
 602         acpi_power_remove_fs(device);
 603
 604         kfree(resource);
 605
 606         return 0;
 607 }
 608
 609 static int __init acpi_power_init(void)
 610 {
 611         int result = 0;
 612
 613
 614         if (acpi_disabled)
 615                 return 0;
 616
 617         INIT_LIST_HEAD(&acpi_power_resource_list);
 618
 619         acpi_power_dir = proc_mkdir(ACPI_POWER_CLASS, acpi_root_dir);
 620         if (!acpi_power_dir)
 621                 return -ENODEV;
 622
 623         result = acpi_bus_register_driver(&acpi_power_driver);
 624         if (result < 0) {
 625                 remove_proc_entry(ACPI_POWER_CLASS, acpi_root_dir);
 626                 return -ENODEV;
 627         }
 628
 629         return 0;
 630 }
 631
 632 subsys_initcall(acpi_power_init);