drivers/acpi/power_meter.c

   1 /*
   2  * A hwmon driver for ACPI 4.0 power meters
   3  * Copyright (C) 2009 IBM
   4  *
   5  * Author: Darrick J. Wong <djwong@us.ibm.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #include <linux/module.h>
  23 #include <linux/hwmon.h>
  24 #include <linux/hwmon-sysfs.h>
  25 #include <linux/jiffies.h>
  26 #include <linux/mutex.h>
  27 #include <linux/dmi.h>
  28 #include <linux/kdev_t.h>
  29 #include <linux/sched.h>
  30 #include <linux/time.h>
  31 #include <acpi/acpi_drivers.h>
  32 #include <acpi/acpi_bus.h>
  33
  34 #define ACPI_POWER_METER_NAME           "power_meter"
  35 ACPI_MODULE_NAME(ACPI_POWER_METER_NAME);
  36 #define ACPI_POWER_METER_DEVICE_NAME    "Power Meter"
  37 #define ACPI_POWER_METER_CLASS          "power_meter_resource"
  38
  39 #define NUM_SENSORS                     17
  40
  41 #define POWER_METER_CAN_MEASURE (1 << 0)
  42 #define POWER_METER_CAN_TRIP    (1 << 1)
  43 #define POWER_METER_CAN_CAP     (1 << 2)
  44 #define POWER_METER_CAN_NOTIFY  (1 << 3)
  45 #define POWER_METER_IS_BATTERY  (1 << 8)
  46 #define UNKNOWN_HYSTERESIS      0xFFFFFFFF
  47
  48 #define METER_NOTIFY_CONFIG     0x80
  49 #define METER_NOTIFY_TRIP       0x81
  50 #define METER_NOTIFY_CAP        0x82
  51 #define METER_NOTIFY_CAPPING    0x83
  52 #define METER_NOTIFY_INTERVAL   0x84
  53
  54 #define POWER_AVERAGE_NAME      "power1_average"
  55 #define POWER_CAP_NAME          "power1_cap"
  56 #define POWER_AVG_INTERVAL_NAME "power1_average_interval"
  57 #define POWER_ALARM_NAME        "power1_alarm"
  58
  59 static int cap_in_hardware;
  60 static int force_cap_on;
  61
  62 static int can_cap_in_hardware(void)
  63 {
  64         return force_cap_on || cap_in_hardware;
  65 }
  66
  67 static struct acpi_device_id power_meter_ids[] = {
  68         {"ACPI000D", 0},
  69         {"", 0},
  70 };
  71 MODULE_DEVICE_TABLE(acpi, power_meter_ids);
  72
  73 struct acpi_power_meter_capabilities {
  74         acpi_integer            flags;
  75         acpi_integer            units;
  76         acpi_integer            type;
  77         acpi_integer            accuracy;
  78         acpi_integer            sampling_time;
  79         acpi_integer            min_avg_interval;
  80         acpi_integer            max_avg_interval;
  81         acpi_integer            hysteresis;
  82         acpi_integer            configurable_cap;
  83         acpi_integer            min_cap;
  84         acpi_integer            max_cap;
  85 };
  86
  87 struct acpi_power_meter_resource {
  88         struct acpi_device      *acpi_dev;
  89         acpi_bus_id             name;
  90         struct mutex            lock;
  91         struct device           *hwmon_dev;
  92         struct acpi_power_meter_capabilities    caps;
  93         acpi_string             model_number;
  94         acpi_string             serial_number;
  95         acpi_string             oem_info;
  96         acpi_integer            power;
  97         acpi_integer            cap;
  98         acpi_integer            avg_interval;
  99         int                     sensors_valid;
 100         unsigned long           sensors_last_updated;
 101         struct sensor_device_attribute  sensors[NUM_SENSORS];
 102         int                     num_sensors;
 103         int                     trip[2];
 104         int                     num_domain_devices;
 105         struct acpi_device      **domain_devices;
 106         struct kobject          *holders_dir;
 107 };
 108
 109 struct ro_sensor_template {
 110         char *label;
 111         ssize_t (*show)(struct device *dev,
 112                         struct device_attribute *devattr,
 113                         char *buf);
 114         int index;
 115 };
 116
 117 struct rw_sensor_template {
 118         char *label;
 119         ssize_t (*show)(struct device *dev,
 120                         struct device_attribute *devattr,
 121                         char *buf);
 122         ssize_t (*set)(struct device *dev,
 123                        struct device_attribute *devattr,
 124                        const char *buf, size_t count);
 125         int index;
 126 };
 127
 128 /* Averaging interval */
 129 static int update_avg_interval(struct acpi_power_meter_resource *resource)
 130 {
 131         unsigned long long data;
 132         acpi_status status;
 133
 134         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GAI",
 135                                        NULL, &data);
 136         if (ACPI_FAILURE(status)) {
 137                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GAI"));
 138                 return -ENODEV;
 139         }
 140
 141         resource->avg_interval = data;
 142         return 0;
 143 }
 144
 145 static ssize_t show_avg_interval(struct device *dev,
 146                                  struct device_attribute *devattr,
 147                                  char *buf)
 148 {
 149         struct acpi_device *acpi_dev = to_acpi_device(dev);
 150         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 151
 152         mutex_lock(&resource->lock);
 153         update_avg_interval(resource);
 154         mutex_unlock(&resource->lock);
 155
 156         return sprintf(buf, "%llu\n", resource->avg_interval);
 157 }
 158
 159 static ssize_t set_avg_interval(struct device *dev,
 160                                 struct device_attribute *devattr,
 161                                 const char *buf, size_t count)
 162 {
 163         struct acpi_device *acpi_dev = to_acpi_device(dev);
 164         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 165         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 166         struct acpi_object_list args = { 1, &arg0 };
 167         int res;
 168         unsigned long temp;
 169         unsigned long long data;
 170         acpi_status status;
 171
 172         res = strict_strtoul(buf, 10, &temp);
 173         if (res)
 174                 return res;
 175
 176         if (temp > resource->caps.max_avg_interval ||
 177             temp < resource->caps.min_avg_interval)
 178                 return -EINVAL;
 179         arg0.integer.value = temp;
 180
 181         mutex_lock(&resource->lock);
 182         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PAI",
 183                                        &args, &data);
 184         if (!ACPI_FAILURE(status))
 185                 resource->avg_interval = temp;
 186         mutex_unlock(&resource->lock);
 187
 188         if (ACPI_FAILURE(status)) {
 189                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PAI"));
 190                 return -EINVAL;
 191         }
 192
 193         /* _PAI returns 0 on success, nonzero otherwise */
 194         if (data)
 195                 return -EINVAL;
 196
 197         return count;
 198 }
 199
 200 /* Cap functions */
 201 static int update_cap(struct acpi_power_meter_resource *resource)
 202 {
 203         unsigned long long data;
 204         acpi_status status;
 205
 206         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GHL",
 207                                        NULL, &data);
 208         if (ACPI_FAILURE(status)) {
 209                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GHL"));
 210                 return -ENODEV;
 211         }
 212
 213         resource->cap = data;
 214         return 0;
 215 }
 216
 217 static ssize_t show_cap(struct device *dev,
 218                         struct device_attribute *devattr,
 219                         char *buf)
 220 {
 221         struct acpi_device *acpi_dev = to_acpi_device(dev);
 222         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 223
 224         mutex_lock(&resource->lock);
 225         update_cap(resource);
 226         mutex_unlock(&resource->lock);
 227
 228         return sprintf(buf, "%llu\n", resource->cap * 1000);
 229 }
 230
 231 static ssize_t set_cap(struct device *dev, struct device_attribute *devattr,
 232                        const char *buf, size_t count)
 233 {
 234         struct acpi_device *acpi_dev = to_acpi_device(dev);
 235         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 236         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 237         struct acpi_object_list args = { 1, &arg0 };
 238         int res;
 239         unsigned long temp;
 240         unsigned long long data;
 241         acpi_status status;
 242
 243         res = strict_strtoul(buf, 10, &temp);
 244         if (res)
 245                 return res;
 246
 247         temp /= 1000;
 248         if (temp > resource->caps.max_cap || temp < resource->caps.min_cap)
 249                 return -EINVAL;
 250         arg0.integer.value = temp;
 251
 252         mutex_lock(&resource->lock);
 253         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_SHL",
 254                                        &args, &data);
 255         if (!ACPI_FAILURE(status))
 256                 resource->cap = temp;
 257         mutex_unlock(&resource->lock);
 258
 259         if (ACPI_FAILURE(status)) {
 260                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SHL"));
 261                 return -EINVAL;
 262         }
 263
 264         /* _SHL returns 0 on success, nonzero otherwise */
 265         if (data)
 266                 return -EINVAL;
 267
 268         return count;
 269 }
 270
 271 /* Power meter trip points */
 272 static int set_acpi_trip(struct acpi_power_meter_resource *resource)
 273 {
 274         union acpi_object arg_objs[] = {
 275                 {ACPI_TYPE_INTEGER},
 276                 {ACPI_TYPE_INTEGER}
 277         };
 278         struct acpi_object_list args = { 2, arg_objs };
 279         unsigned long long data;
 280         acpi_status status;
 281
 282         /* Both trip levels must be set */
 283         if (resource->trip[0] < 0 || resource->trip[1] < 0)
 284                 return 0;
 285
 286         /* This driver stores min, max; ACPI wants max, min. */
 287         arg_objs[0].integer.value = resource->trip[1];
 288         arg_objs[1].integer.value = resource->trip[0];
 289
 290         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PTP",
 291                                        &args, &data);
 292         if (ACPI_FAILURE(status)) {
 293                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTP"));
 294                 return -EINVAL;
 295         }
 296
 297         return data;
 298 }
 299
 300 static ssize_t set_trip(struct device *dev, struct device_attribute *devattr,
 301                         const char *buf, size_t count)
 302 {
 303         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 304         struct acpi_device *acpi_dev = to_acpi_device(dev);
 305         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 306         int res;
 307         unsigned long temp;
 308
 309         res = strict_strtoul(buf, 10, &temp);
 310         if (res)
 311                 return res;
 312
 313         temp /= 1000;
 314         if (temp < 0)
 315                 return -EINVAL;
 316
 317         mutex_lock(&resource->lock);
 318         resource->trip[attr->index - 7] = temp;
 319         res = set_acpi_trip(resource);
 320         mutex_unlock(&resource->lock);
 321
 322         if (res)
 323                 return res;
 324
 325         return count;
 326 }
 327
 328 /* Power meter */
 329 static int update_meter(struct acpi_power_meter_resource *resource)
 330 {
 331         unsigned long long data;
 332         acpi_status status;
 333         unsigned long local_jiffies = jiffies;
 334
 335         if (time_before(local_jiffies, resource->sensors_last_updated +
 336                         msecs_to_jiffies(resource->caps.sampling_time)) &&
 337                         resource->sensors_valid)
 338                 return 0;
 339
 340         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PMM",
 341                                        NULL, &data);
 342         if (ACPI_FAILURE(status)) {
 343                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMM"));
 344                 return -ENODEV;
 345         }
 346
 347         resource->power = data;
 348         resource->sensors_valid = 1;
 349         resource->sensors_last_updated = jiffies;
 350         return 0;
 351 }
 352
 353 static ssize_t show_power(struct device *dev,
 354                           struct device_attribute *devattr,
 355                           char *buf)
 356 {
 357         struct acpi_device *acpi_dev = to_acpi_device(dev);
 358         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 359
 360         mutex_lock(&resource->lock);
 361         update_meter(resource);
 362         mutex_unlock(&resource->lock);
 363
 364         return sprintf(buf, "%llu\n", resource->power * 1000);
 365 }
 366
 367 /* Miscellaneous */
 368 static ssize_t show_str(struct device *dev,
 369                         struct device_attribute *devattr,
 370                         char *buf)
 371 {
 372         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 373         struct acpi_device *acpi_dev = to_acpi_device(dev);
 374         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 375         acpi_string val;
 376
 377         switch (attr->index) {
 378         case 0:
 379                 val = resource->model_number;
 380                 break;
 381         case 1:
 382                 val = resource->serial_number;
 383                 break;
 384         case 2:
 385                 val = resource->oem_info;
 386                 break;
 387         default:
 388                 BUG();
 389         }
 390
 391         return sprintf(buf, "%s\n", val);
 392 }
 393
 394 static ssize_t show_val(struct device *dev,
 395                         struct device_attribute *devattr,
 396                         char *buf)
 397 {
 398         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 399         struct acpi_device *acpi_dev = to_acpi_device(dev);
 400         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 401         acpi_integer val = 0;
 402
 403         switch (attr->index) {
 404         case 0:
 405                 val = resource->caps.min_avg_interval;
 406                 break;
 407         case 1:
 408                 val = resource->caps.max_avg_interval;
 409                 break;
 410         case 2:
 411                 val = resource->caps.min_cap * 1000;
 412                 break;
 413         case 3:
 414                 val = resource->caps.max_cap * 1000;
 415                 break;
 416         case 4:
 417                 if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
 418                         return sprintf(buf, "unknown\n");
 419
 420                 val = resource->caps.hysteresis * 1000;
 421                 break;
 422         case 5:
 423                 if (resource->caps.flags & POWER_METER_IS_BATTERY)
 424                         val = 1;
 425                 else
 426                         val = 0;
 427                 break;
 428         case 6:
 429                 if (resource->power > resource->cap)
 430                         val = 1;
 431                 else
 432                         val = 0;
 433                 break;
 434         case 7:
 435         case 8:
 436                 if (resource->trip[attr->index - 7] < 0)
 437                         return sprintf(buf, "unknown\n");
 438
 439                 val = resource->trip[attr->index - 7] * 1000;
 440                 break;
 441         default:
 442                 BUG();
 443         }
 444
 445         return sprintf(buf, "%llu\n", val);
 446 }
 447
 448 static ssize_t show_accuracy(struct device *dev,
 449                              struct device_attribute *devattr,
 450                              char *buf)
 451 {
 452         struct acpi_device *acpi_dev = to_acpi_device(dev);
 453         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 454         unsigned int acc = resource->caps.accuracy;
 455
 456         return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
 457 }
 458
 459 static ssize_t show_name(struct device *dev,
 460                          struct device_attribute *devattr,
 461                          char *buf)
 462 {
 463         return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
 464 }
 465
 466 /* Sensor descriptions.  If you add a sensor, update NUM_SENSORS above! */
 467 static struct ro_sensor_template meter_ro_attrs[] = {
 468 {POWER_AVERAGE_NAME, show_power, 0},
 469 {"power1_accuracy", show_accuracy, 0},
 470 {"power1_average_interval_min", show_val, 0},
 471 {"power1_average_interval_max", show_val, 1},
 472 {"power1_is_battery", show_val, 5},
 473 {NULL, NULL, 0},
 474 };
 475
 476 static struct rw_sensor_template meter_rw_attrs[] = {
 477 {POWER_AVG_INTERVAL_NAME, show_avg_interval, set_avg_interval, 0},
 478 {NULL, NULL, NULL, 0},
 479 };
 480
 481 static struct ro_sensor_template misc_cap_attrs[] = {
 482 {"power1_cap_min", show_val, 2},
 483 {"power1_cap_max", show_val, 3},
 484 {"power1_cap_hyst", show_val, 4},
 485 {POWER_ALARM_NAME, show_val, 6},
 486 {NULL, NULL, 0},
 487 };
 488
 489 static struct ro_sensor_template ro_cap_attrs[] = {
 490 {POWER_CAP_NAME, show_cap, 0},
 491 {NULL, NULL, 0},
 492 };
 493
 494 static struct rw_sensor_template rw_cap_attrs[] = {
 495 {POWER_CAP_NAME, show_cap, set_cap, 0},
 496 {NULL, NULL, NULL, 0},
 497 };
 498
 499 static struct rw_sensor_template trip_attrs[] = {
 500 {"power1_average_min", show_val, set_trip, 7},
 501 {"power1_average_max", show_val, set_trip, 8},
 502 {NULL, NULL, NULL, 0},
 503 };
 504
 505 static struct ro_sensor_template misc_attrs[] = {
 506 {"name", show_name, 0},
 507 {"power1_model_number", show_str, 0},
 508 {"power1_oem_info", show_str, 2},
 509 {"power1_serial_number", show_str, 1},
 510 {NULL, NULL, 0},
 511 };
 512
 513 /* Read power domain data */
 514 static void remove_domain_devices(struct acpi_power_meter_resource *resource)
 515 {
 516         int i;
 517
 518         if (!resource->num_domain_devices)
 519                 return;
 520
 521         for (i = 0; i < resource->num_domain_devices; i++) {
 522                 struct acpi_device *obj = resource->domain_devices[i];
 523                 if (!obj)
 524                         continue;
 525
 526                 sysfs_remove_link(resource->holders_dir,
 527                                   kobject_name(&obj->dev.kobj));
 528                 put_device(&obj->dev);
 529         }
 530
 531         kfree(resource->domain_devices);
 532         kobject_put(resource->holders_dir);
 533 }
 534
 535 static int read_domain_devices(struct acpi_power_meter_resource *resource)
 536 {
 537         int res = 0;
 538         int i;
 539         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 540         union acpi_object *pss;
 541         acpi_status status;
 542
 543         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
 544                                       &buffer);
 545         if (ACPI_FAILURE(status)) {
 546                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMD"));
 547                 return -ENODEV;
 548         }
 549
 550         pss = buffer.pointer;
 551         if (!pss ||
 552             pss->type != ACPI_TYPE_PACKAGE) {
 553                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 554                         "Invalid _PMD data\n");
 555                 res = -EFAULT;
 556                 goto end;
 557         }
 558
 559         if (!pss->package.count)
 560                 goto end;
 561
 562         resource->domain_devices = kzalloc(sizeof(struct acpi_device *) *
 563                                            pss->package.count, GFP_KERNEL);
 564         if (!resource->domain_devices) {
 565                 res = -ENOMEM;
 566                 goto end;
 567         }
 568
 569         resource->holders_dir = kobject_create_and_add("measures",
 570                                         &resource->acpi_dev->dev.kobj);
 571         if (!resource->holders_dir) {
 572                 res = -ENOMEM;
 573                 goto exit_free;
 574         }
 575
 576         resource->num_domain_devices = pss->package.count;
 577
 578         for (i = 0; i < pss->package.count; i++) {
 579                 struct acpi_device *obj;
 580                 union acpi_object *element = &(pss->package.elements[i]);
 581
 582                 /* Refuse non-references */
 583                 if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
 584                         continue;
 585
 586                 /* Create a symlink to domain objects */
 587                 resource->domain_devices[i] = NULL;
 588                 status = acpi_bus_get_device(element->reference.handle,
 589                                              &resource->domain_devices[i]);
 590                 if (ACPI_FAILURE(status))
 591                         continue;
 592
 593                 obj = resource->domain_devices[i];
 594                 get_device(&obj->dev);
 595
 596                 res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
 597                                       kobject_name(&obj->dev.kobj));
 598                 if (res) {
 599                         put_device(&obj->dev);
 600                         resource->domain_devices[i] = NULL;
 601                 }
 602         }
 603
 604         res = 0;
 605         goto end;
 606
 607 exit_free:
 608         kfree(resource->domain_devices);
 609 end:
 610         kfree(buffer.pointer);
 611         return res;
 612 }
 613
 614 /* Registration and deregistration */
 615 static int register_ro_attrs(struct acpi_power_meter_resource *resource,
 616                              struct ro_sensor_template *ro)
 617 {
 618         struct device *dev = &resource->acpi_dev->dev;
 619         struct sensor_device_attribute *sensors =
 620                 &resource->sensors[resource->num_sensors];
 621         int res = 0;
 622
 623         while (ro->label) {
 624                 sensors->dev_attr.attr.name = ro->label;
 625                 sensors->dev_attr.attr.mode = S_IRUGO;
 626                 sensors->dev_attr.show = ro->show;
 627                 sensors->index = ro->index;
 628
 629                 res = device_create_file(dev, &sensors->dev_attr);
 630                 if (res) {
 631                         sensors->dev_attr.attr.name = NULL;
 632                         goto error;
 633                 }
 634                 sensors++;
 635                 resource->num_sensors++;
 636                 ro++;
 637         }
 638
 639 error:
 640         return res;
 641 }
 642
 643 static int register_rw_attrs(struct acpi_power_meter_resource *resource,
 644                              struct rw_sensor_template *rw)
 645 {
 646         struct device *dev = &resource->acpi_dev->dev;
 647         struct sensor_device_attribute *sensors =
 648                 &resource->sensors[resource->num_sensors];
 649         int res = 0;
 650
 651         while (rw->label) {
 652                 sensors->dev_attr.attr.name = rw->label;
 653                 sensors->dev_attr.attr.mode = S_IRUGO | S_IWUSR;
 654                 sensors->dev_attr.show = rw->show;
 655                 sensors->dev_attr.store = rw->set;
 656                 sensors->index = rw->index;
 657
 658                 res = device_create_file(dev, &sensors->dev_attr);
 659                 if (res) {
 660                         sensors->dev_attr.attr.name = NULL;
 661                         goto error;
 662                 }
 663                 sensors++;
 664                 resource->num_sensors++;
 665                 rw++;
 666         }
 667
 668 error:
 669         return res;
 670 }
 671
 672 static void remove_attrs(struct acpi_power_meter_resource *resource)
 673 {
 674         int i;
 675
 676         for (i = 0; i < resource->num_sensors; i++) {
 677                 if (!resource->sensors[i].dev_attr.attr.name)
 678                         continue;
 679                 device_remove_file(&resource->acpi_dev->dev,
 680                                    &resource->sensors[i].dev_attr);
 681         }
 682
 683         remove_domain_devices(resource);
 684
 685         resource->num_sensors = 0;
 686 }
 687
 688 static int setup_attrs(struct acpi_power_meter_resource *resource)
 689 {
 690         int res = 0;
 691
 692         res = read_domain_devices(resource);
 693         if (res)
 694                 return res;
 695
 696         if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
 697                 res = register_ro_attrs(resource, meter_ro_attrs);
 698                 if (res)
 699                         goto error;
 700                 res = register_rw_attrs(resource, meter_rw_attrs);
 701                 if (res)
 702                         goto error;
 703         }
 704
 705         if (resource->caps.flags & POWER_METER_CAN_CAP) {
 706                 if (!can_cap_in_hardware()) {
 707                         dev_err(&resource->acpi_dev->dev,
 708                                 "Ignoring unsafe software power cap!\n");
 709                         goto skip_unsafe_cap;
 710                 }
 711
 712                 if (resource->caps.configurable_cap) {
 713                         res = register_rw_attrs(resource, rw_cap_attrs);
 714                         if (res)
 715                                 goto error;
 716                 } else {
 717                         res = register_ro_attrs(resource, ro_cap_attrs);
 718                         if (res)
 719                                 goto error;
 720                 }
 721                 res = register_ro_attrs(resource, misc_cap_attrs);
 722                 if (res)
 723                         goto error;
 724         }
 725 skip_unsafe_cap:
 726
 727         if (resource->caps.flags & POWER_METER_CAN_TRIP) {
 728                 res = register_rw_attrs(resource, trip_attrs);
 729                 if (res)
 730                         goto error;
 731         }
 732
 733         res = register_ro_attrs(resource, misc_attrs);
 734         if (res)
 735                 goto error;
 736
 737         return res;
 738 error:
 739         remove_domain_devices(resource);
 740         remove_attrs(resource);
 741         return res;
 742 }
 743
 744 static void free_capabilities(struct acpi_power_meter_resource *resource)
 745 {
 746         acpi_string *str;
 747         int i;
 748
 749         str = &resource->model_number;
 750         for (i = 0; i < 3; i++, str++)
 751                 kfree(*str);
 752 }
 753
 754 static int read_capabilities(struct acpi_power_meter_resource *resource)
 755 {
 756         int res = 0;
 757         int i;
 758         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 759         struct acpi_buffer state = { 0, NULL };
 760         struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
 761         union acpi_object *pss;
 762         acpi_string *str;
 763         acpi_status status;
 764
 765         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
 766                                       &buffer);
 767         if (ACPI_FAILURE(status)) {
 768                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMC"));
 769                 return -ENODEV;
 770         }
 771
 772         pss = buffer.pointer;
 773         if (!pss ||
 774             pss->type != ACPI_TYPE_PACKAGE ||
 775             pss->package.count != 14) {
 776                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 777                         "Invalid _PMC data\n");
 778                 res = -EFAULT;
 779                 goto end;
 780         }
 781
 782         /* Grab all the integer data at once */
 783         state.length = sizeof(struct acpi_power_meter_capabilities);
 784         state.pointer = &resource->caps;
 785
 786         status = acpi_extract_package(pss, &format, &state);
 787         if (ACPI_FAILURE(status)) {
 788                 ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
 789                 res = -EFAULT;
 790                 goto end;
 791         }
 792
 793         if (resource->caps.units) {
 794                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 795                         "Unknown units %llu.\n",
 796                         resource->caps.units);
 797                 res = -EINVAL;
 798                 goto end;
 799         }
 800
 801         /* Grab the string data */
 802         str = &resource->model_number;
 803
 804         for (i = 11; i < 14; i++) {
 805                 union acpi_object *element = &(pss->package.elements[i]);
 806
 807                 if (element->type != ACPI_TYPE_STRING) {
 808                         res = -EINVAL;
 809                         goto error;
 810                 }
 811
 812                 *str = kzalloc(sizeof(u8) * (element->string.length + 1),
 813                                GFP_KERNEL);
 814                 if (!*str) {
 815                         res = -ENOMEM;
 816                         goto error;
 817                 }
 818
 819                 strncpy(*str, element->string.pointer, element->string.length);
 820                 str++;
 821         }
 822
 823         dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
 824         goto end;
 825 error:
 826         str = &resource->model_number;
 827         for (i = 0; i < 3; i++, str++)
 828                 kfree(*str);
 829 end:
 830         kfree(buffer.pointer);
 831         return res;
 832 }
 833
 834 /* Handle ACPI event notifications */
 835 static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
 836 {
 837         struct acpi_power_meter_resource *resource;
 838         int res;
 839
 840         if (!device || !acpi_driver_data(device))
 841                 return;
 842
 843         resource = acpi_driver_data(device);
 844
 845         mutex_lock(&resource->lock);
 846         switch (event) {
 847         case METER_NOTIFY_CONFIG:
 848                 free_capabilities(resource);
 849                 res = read_capabilities(resource);
 850                 if (res)
 851                         break;
 852
 853                 remove_attrs(resource);
 854                 setup_attrs(resource);
 855                 break;
 856         case METER_NOTIFY_TRIP:
 857                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
 858                 update_meter(resource);
 859                 break;
 860         case METER_NOTIFY_CAP:
 861                 sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
 862                 update_cap(resource);
 863                 break;
 864         case METER_NOTIFY_INTERVAL:
 865                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
 866                 update_avg_interval(resource);
 867                 break;
 868         case METER_NOTIFY_CAPPING:
 869                 sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
 870                 dev_info(&device->dev, "Capping in progress.\n");
 871                 break;
 872         default:
 873                 BUG();
 874         }
 875         mutex_unlock(&resource->lock);
 876
 877         acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS,
 878                                         dev_name(&device->dev), event, 0);
 879 }
 880
 881 static int acpi_power_meter_add(struct acpi_device *device)
 882 {
 883         int res;
 884         struct acpi_power_meter_resource *resource;
 885
 886         if (!device)
 887                 return -EINVAL;
 888
 889         resource = kzalloc(sizeof(struct acpi_power_meter_resource),
 890                            GFP_KERNEL);
 891         if (!resource)
 892                 return -ENOMEM;
 893
 894         resource->sensors_valid = 0;
 895         resource->acpi_dev = device;
 896         mutex_init(&resource->lock);
 897         strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
 898         strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
 899         device->driver_data = resource;
 900
 901         free_capabilities(resource);
 902         res = read_capabilities(resource);
 903         if (res)
 904                 goto exit_free;
 905
 906         resource->trip[0] = resource->trip[1] = -1;
 907
 908         res = setup_attrs(resource);
 909         if (res)
 910                 goto exit_free;
 911
 912         resource->hwmon_dev = hwmon_device_register(&device->dev);
 913         if (IS_ERR(resource->hwmon_dev)) {
 914                 res = PTR_ERR(resource->hwmon_dev);
 915                 goto exit_remove;
 916         }
 917
 918         res = 0;
 919         goto exit;
 920
 921 exit_remove:
 922         remove_attrs(resource);
 923 exit_free:
 924         kfree(resource);
 925 exit:
 926         return res;
 927 }
 928
 929 static int acpi_power_meter_remove(struct acpi_device *device, int type)
 930 {
 931         struct acpi_power_meter_resource *resource;
 932
 933         if (!device || !acpi_driver_data(device))
 934                 return -EINVAL;
 935
 936         resource = acpi_driver_data(device);
 937         hwmon_device_unregister(resource->hwmon_dev);
 938
 939         free_capabilities(resource);
 940         remove_attrs(resource);
 941
 942         kfree(resource);
 943         return 0;
 944 }
 945
 946 static int acpi_power_meter_resume(struct acpi_device *device)
 947 {
 948         struct acpi_power_meter_resource *resource;
 949
 950         if (!device || !acpi_driver_data(device))
 951                 return -EINVAL;
 952
 953         resource = acpi_driver_data(device);
 954         free_capabilities(resource);
 955         read_capabilities(resource);
 956
 957         return 0;
 958 }
 959
 960 static struct acpi_driver acpi_power_meter_driver = {
 961         .name = "power_meter",
 962         .class = ACPI_POWER_METER_CLASS,
 963         .ids = power_meter_ids,
 964         .ops = {
 965                 .add = acpi_power_meter_add,
 966                 .remove = acpi_power_meter_remove,
 967                 .resume = acpi_power_meter_resume,
 968                 .notify = acpi_power_meter_notify,
 969                 },
 970 };
 971
 972 /* Module init/exit routines */
 973 static int __init enable_cap_knobs(const struct dmi_system_id *d)
 974 {
 975         cap_in_hardware = 1;
 976         return 0;
 977 }
 978
 979 static struct dmi_system_id __initdata pm_dmi_table[] = {
 980         {
 981                 enable_cap_knobs, "IBM Active Energy Manager",
 982                 {
 983                         DMI_MATCH(DMI_SYS_VENDOR, "IBM")
 984                 },
 985         },
 986         {}
 987 };
 988
 989 static int __init acpi_power_meter_init(void)
 990 {
 991         int result;
 992
 993         if (acpi_disabled)
 994                 return -ENODEV;
 995
 996         dmi_check_system(pm_dmi_table);
 997
 998         result = acpi_bus_register_driver(&acpi_power_meter_driver);
 999         if (result < 0)
1000                 return -ENODEV;
1001
1002         return 0;
1003 }
1004
1005 static void __exit acpi_power_meter_exit(void)
1006 {
1007         acpi_bus_unregister_driver(&acpi_power_meter_driver);
1008 }
1009
1010 MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
1011 MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
1012 MODULE_LICENSE("GPL");
1013
1014 module_param(force_cap_on, bool, 0644);
1015 MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1016
1017 module_init(acpi_power_meter_init);
1018 module_exit(acpi_power_meter_exit);