drivers/hwmon/acpi_power_meter.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * A hwmon driver for ACPI 4.0 power meters
   4  * Copyright (C) 2009 IBM
   5  *
   6  * Author: Darrick J. Wong <darrick.wong@oracle.com>
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/hwmon.h>
  11 #include <linux/hwmon-sysfs.h>
  12 #include <linux/jiffies.h>
  13 #include <linux/mutex.h>
  14 #include <linux/dmi.h>
  15 #include <linux/slab.h>
  16 #include <linux/kdev_t.h>
  17 #include <linux/sched.h>
  18 #include <linux/time.h>
  19 #include <linux/err.h>
  20 #include <linux/acpi.h>
  21
  22 #define ACPI_POWER_METER_NAME           "power_meter"
  23 ACPI_MODULE_NAME(ACPI_POWER_METER_NAME);
  24 #define ACPI_POWER_METER_DEVICE_NAME    "Power Meter"
  25 #define ACPI_POWER_METER_CLASS          "pwr_meter_resource"
  26
  27 #define NUM_SENSORS                     17
  28
  29 #define POWER_METER_CAN_MEASURE (1 << 0)
  30 #define POWER_METER_CAN_TRIP    (1 << 1)
  31 #define POWER_METER_CAN_CAP     (1 << 2)
  32 #define POWER_METER_CAN_NOTIFY  (1 << 3)
  33 #define POWER_METER_IS_BATTERY  (1 << 8)
  34 #define UNKNOWN_HYSTERESIS      0xFFFFFFFF
  35 #define UNKNOWN_POWER           0xFFFFFFFF
  36
  37 #define METER_NOTIFY_CONFIG     0x80
  38 #define METER_NOTIFY_TRIP       0x81
  39 #define METER_NOTIFY_CAP        0x82
  40 #define METER_NOTIFY_CAPPING    0x83
  41 #define METER_NOTIFY_INTERVAL   0x84
  42
  43 #define POWER_AVERAGE_NAME      "power1_average"
  44 #define POWER_CAP_NAME          "power1_cap"
  45 #define POWER_AVG_INTERVAL_NAME "power1_average_interval"
  46 #define POWER_ALARM_NAME        "power1_alarm"
  47
  48 static int cap_in_hardware;
  49 static bool force_cap_on;
  50
  51 static int can_cap_in_hardware(void)
  52 {
  53         return force_cap_on || cap_in_hardware;
  54 }
  55
  56 static const struct acpi_device_id power_meter_ids[] = {
  57         {"ACPI000D", 0},
  58         {"", 0},
  59 };
  60 MODULE_DEVICE_TABLE(acpi, power_meter_ids);
  61
  62 struct acpi_power_meter_capabilities {
  63         u64             flags;
  64         u64             units;
  65         u64             type;
  66         u64             accuracy;
  67         u64             sampling_time;
  68         u64             min_avg_interval;
  69         u64             max_avg_interval;
  70         u64             hysteresis;
  71         u64             configurable_cap;
  72         u64             min_cap;
  73         u64             max_cap;
  74 };
  75
  76 struct acpi_power_meter_resource {
  77         struct acpi_device      *acpi_dev;
  78         acpi_bus_id             name;
  79         struct mutex            lock;
  80         struct device           *hwmon_dev;
  81         struct acpi_power_meter_capabilities    caps;
  82         acpi_string             model_number;
  83         acpi_string             serial_number;
  84         acpi_string             oem_info;
  85         u64             power;
  86         u64             cap;
  87         u64             avg_interval;
  88         int                     sensors_valid;
  89         unsigned long           sensors_last_updated;
  90         struct sensor_device_attribute  sensors[NUM_SENSORS];
  91         int                     num_sensors;
  92         s64                     trip[2];
  93         int                     num_domain_devices;
  94         struct acpi_device      **domain_devices;
  95         struct kobject          *holders_dir;
  96 };
  97
  98 struct sensor_template {
  99         char *label;
 100         ssize_t (*show)(struct device *dev,
 101                         struct device_attribute *devattr,
 102                         char *buf);
 103         ssize_t (*set)(struct device *dev,
 104                        struct device_attribute *devattr,
 105                        const char *buf, size_t count);
 106         int index;
 107 };
 108
 109 /* Averaging interval */
 110 static int update_avg_interval(struct acpi_power_meter_resource *resource)
 111 {
 112         unsigned long long data;
 113         acpi_status status;
 114
 115         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GAI",
 116                                        NULL, &data);
 117         if (ACPI_FAILURE(status)) {
 118                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GAI"));
 119                 return -ENODEV;
 120         }
 121
 122         resource->avg_interval = data;
 123         return 0;
 124 }
 125
 126 static ssize_t show_avg_interval(struct device *dev,
 127                                  struct device_attribute *devattr,
 128                                  char *buf)
 129 {
 130         struct acpi_device *acpi_dev = to_acpi_device(dev);
 131         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 132
 133         mutex_lock(&resource->lock);
 134         update_avg_interval(resource);
 135         mutex_unlock(&resource->lock);
 136
 137         return sprintf(buf, "%llu\n", resource->avg_interval);
 138 }
 139
 140 static ssize_t set_avg_interval(struct device *dev,
 141                                 struct device_attribute *devattr,
 142                                 const char *buf, size_t count)
 143 {
 144         struct acpi_device *acpi_dev = to_acpi_device(dev);
 145         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 146         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 147         struct acpi_object_list args = { 1, &arg0 };
 148         int res;
 149         unsigned long temp;
 150         unsigned long long data;
 151         acpi_status status;
 152
 153         res = kstrtoul(buf, 10, &temp);
 154         if (res)
 155                 return res;
 156
 157         if (temp > resource->caps.max_avg_interval ||
 158             temp < resource->caps.min_avg_interval)
 159                 return -EINVAL;
 160         arg0.integer.value = temp;
 161
 162         mutex_lock(&resource->lock);
 163         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PAI",
 164                                        &args, &data);
 165         if (!ACPI_FAILURE(status))
 166                 resource->avg_interval = temp;
 167         mutex_unlock(&resource->lock);
 168
 169         if (ACPI_FAILURE(status)) {
 170                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PAI"));
 171                 return -EINVAL;
 172         }
 173
 174         /* _PAI returns 0 on success, nonzero otherwise */
 175         if (data)
 176                 return -EINVAL;
 177
 178         return count;
 179 }
 180
 181 /* Cap functions */
 182 static int update_cap(struct acpi_power_meter_resource *resource)
 183 {
 184         unsigned long long data;
 185         acpi_status status;
 186
 187         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GHL",
 188                                        NULL, &data);
 189         if (ACPI_FAILURE(status)) {
 190                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GHL"));
 191                 return -ENODEV;
 192         }
 193
 194         resource->cap = data;
 195         return 0;
 196 }
 197
 198 static ssize_t show_cap(struct device *dev,
 199                         struct device_attribute *devattr,
 200                         char *buf)
 201 {
 202         struct acpi_device *acpi_dev = to_acpi_device(dev);
 203         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 204
 205         mutex_lock(&resource->lock);
 206         update_cap(resource);
 207         mutex_unlock(&resource->lock);
 208
 209         return sprintf(buf, "%llu\n", resource->cap * 1000);
 210 }
 211
 212 static ssize_t set_cap(struct device *dev, struct device_attribute *devattr,
 213                        const char *buf, size_t count)
 214 {
 215         struct acpi_device *acpi_dev = to_acpi_device(dev);
 216         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 217         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 218         struct acpi_object_list args = { 1, &arg0 };
 219         int res;
 220         unsigned long temp;
 221         unsigned long long data;
 222         acpi_status status;
 223
 224         res = kstrtoul(buf, 10, &temp);
 225         if (res)
 226                 return res;
 227
 228         temp = DIV_ROUND_CLOSEST(temp, 1000);
 229         if (temp > resource->caps.max_cap || temp < resource->caps.min_cap)
 230                 return -EINVAL;
 231         arg0.integer.value = temp;
 232
 233         mutex_lock(&resource->lock);
 234         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_SHL",
 235                                        &args, &data);
 236         if (!ACPI_FAILURE(status))
 237                 resource->cap = temp;
 238         mutex_unlock(&resource->lock);
 239
 240         if (ACPI_FAILURE(status)) {
 241                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SHL"));
 242                 return -EINVAL;
 243         }
 244
 245         /* _SHL returns 0 on success, nonzero otherwise */
 246         if (data)
 247                 return -EINVAL;
 248
 249         return count;
 250 }
 251
 252 /* Power meter trip points */
 253 static int set_acpi_trip(struct acpi_power_meter_resource *resource)
 254 {
 255         union acpi_object arg_objs[] = {
 256                 {ACPI_TYPE_INTEGER},
 257                 {ACPI_TYPE_INTEGER}
 258         };
 259         struct acpi_object_list args = { 2, arg_objs };
 260         unsigned long long data;
 261         acpi_status status;
 262
 263         /* Both trip levels must be set */
 264         if (resource->trip[0] < 0 || resource->trip[1] < 0)
 265                 return 0;
 266
 267         /* This driver stores min, max; ACPI wants max, min. */
 268         arg_objs[0].integer.value = resource->trip[1];
 269         arg_objs[1].integer.value = resource->trip[0];
 270
 271         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PTP",
 272                                        &args, &data);
 273         if (ACPI_FAILURE(status)) {
 274                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTP"));
 275                 return -EINVAL;
 276         }
 277
 278         /* _PTP returns 0 on success, nonzero otherwise */
 279         if (data)
 280                 return -EINVAL;
 281
 282         return 0;
 283 }
 284
 285 static ssize_t set_trip(struct device *dev, struct device_attribute *devattr,
 286                         const char *buf, size_t count)
 287 {
 288         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 289         struct acpi_device *acpi_dev = to_acpi_device(dev);
 290         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 291         int res;
 292         unsigned long temp;
 293
 294         res = kstrtoul(buf, 10, &temp);
 295         if (res)
 296                 return res;
 297
 298         temp = DIV_ROUND_CLOSEST(temp, 1000);
 299
 300         mutex_lock(&resource->lock);
 301         resource->trip[attr->index - 7] = temp;
 302         res = set_acpi_trip(resource);
 303         mutex_unlock(&resource->lock);
 304
 305         if (res)
 306                 return res;
 307
 308         return count;
 309 }
 310
 311 /* Power meter */
 312 static int update_meter(struct acpi_power_meter_resource *resource)
 313 {
 314         unsigned long long data;
 315         acpi_status status;
 316         unsigned long local_jiffies = jiffies;
 317
 318         if (time_before(local_jiffies, resource->sensors_last_updated +
 319                         msecs_to_jiffies(resource->caps.sampling_time)) &&
 320                         resource->sensors_valid)
 321                 return 0;
 322
 323         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PMM",
 324                                        NULL, &data);
 325         if (ACPI_FAILURE(status)) {
 326                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMM"));
 327                 return -ENODEV;
 328         }
 329
 330         resource->power = data;
 331         resource->sensors_valid = 1;
 332         resource->sensors_last_updated = jiffies;
 333         return 0;
 334 }
 335
 336 static ssize_t show_power(struct device *dev,
 337                           struct device_attribute *devattr,
 338                           char *buf)
 339 {
 340         struct acpi_device *acpi_dev = to_acpi_device(dev);
 341         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 342
 343         mutex_lock(&resource->lock);
 344         update_meter(resource);
 345         mutex_unlock(&resource->lock);
 346
 347         if (resource->power == UNKNOWN_POWER)
 348                 return -ENODATA;
 349
 350         return sprintf(buf, "%llu\n", resource->power * 1000);
 351 }
 352
 353 /* Miscellaneous */
 354 static ssize_t show_str(struct device *dev,
 355                         struct device_attribute *devattr,
 356                         char *buf)
 357 {
 358         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 359         struct acpi_device *acpi_dev = to_acpi_device(dev);
 360         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 361         acpi_string val;
 362         int ret;
 363
 364         mutex_lock(&resource->lock);
 365         switch (attr->index) {
 366         case 0:
 367                 val = resource->model_number;
 368                 break;
 369         case 1:
 370                 val = resource->serial_number;
 371                 break;
 372         case 2:
 373                 val = resource->oem_info;
 374                 break;
 375         default:
 376                 WARN(1, "Implementation error: unexpected attribute index %d\n",
 377                      attr->index);
 378                 val = "";
 379                 break;
 380         }
 381         ret = sprintf(buf, "%s\n", val);
 382         mutex_unlock(&resource->lock);
 383         return ret;
 384 }
 385
 386 static ssize_t show_val(struct device *dev,
 387                         struct device_attribute *devattr,
 388                         char *buf)
 389 {
 390         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 391         struct acpi_device *acpi_dev = to_acpi_device(dev);
 392         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 393         u64 val = 0;
 394
 395         switch (attr->index) {
 396         case 0:
 397                 val = resource->caps.min_avg_interval;
 398                 break;
 399         case 1:
 400                 val = resource->caps.max_avg_interval;
 401                 break;
 402         case 2:
 403                 val = resource->caps.min_cap * 1000;
 404                 break;
 405         case 3:
 406                 val = resource->caps.max_cap * 1000;
 407                 break;
 408         case 4:
 409                 if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
 410                         return sprintf(buf, "unknown\n");
 411
 412                 val = resource->caps.hysteresis * 1000;
 413                 break;
 414         case 5:
 415                 if (resource->caps.flags & POWER_METER_IS_BATTERY)
 416                         val = 1;
 417                 else
 418                         val = 0;
 419                 break;
 420         case 6:
 421                 if (resource->power > resource->cap)
 422                         val = 1;
 423                 else
 424                         val = 0;
 425                 break;
 426         case 7:
 427         case 8:
 428                 if (resource->trip[attr->index - 7] < 0)
 429                         return sprintf(buf, "unknown\n");
 430
 431                 val = resource->trip[attr->index - 7] * 1000;
 432                 break;
 433         default:
 434                 WARN(1, "Implementation error: unexpected attribute index %d\n",
 435                      attr->index);
 436                 break;
 437         }
 438
 439         return sprintf(buf, "%llu\n", val);
 440 }
 441
 442 static ssize_t show_accuracy(struct device *dev,
 443                              struct device_attribute *devattr,
 444                              char *buf)
 445 {
 446         struct acpi_device *acpi_dev = to_acpi_device(dev);
 447         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 448         unsigned int acc = resource->caps.accuracy;
 449
 450         return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
 451 }
 452
 453 static ssize_t show_name(struct device *dev,
 454                          struct device_attribute *devattr,
 455                          char *buf)
 456 {
 457         return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
 458 }
 459
 460 #define RO_SENSOR_TEMPLATE(_label, _show, _index)       \
 461         {                                               \
 462                 .label = _label,                        \
 463                 .show  = _show,                         \
 464                 .index = _index,                        \
 465         }
 466
 467 #define RW_SENSOR_TEMPLATE(_label, _show, _set, _index) \
 468         {                                               \
 469                 .label = _label,                        \
 470                 .show  = _show,                         \
 471                 .set   = _set,                          \
 472                 .index = _index,                        \
 473         }
 474
 475 /* Sensor descriptions.  If you add a sensor, update NUM_SENSORS above! */
 476 static struct sensor_template meter_attrs[] = {
 477         RO_SENSOR_TEMPLATE(POWER_AVERAGE_NAME, show_power, 0),
 478         RO_SENSOR_TEMPLATE("power1_accuracy", show_accuracy, 0),
 479         RO_SENSOR_TEMPLATE("power1_average_interval_min", show_val, 0),
 480         RO_SENSOR_TEMPLATE("power1_average_interval_max", show_val, 1),
 481         RO_SENSOR_TEMPLATE("power1_is_battery", show_val, 5),
 482         RW_SENSOR_TEMPLATE(POWER_AVG_INTERVAL_NAME, show_avg_interval,
 483                 set_avg_interval, 0),
 484         {},
 485 };
 486
 487 static struct sensor_template misc_cap_attrs[] = {
 488         RO_SENSOR_TEMPLATE("power1_cap_min", show_val, 2),
 489         RO_SENSOR_TEMPLATE("power1_cap_max", show_val, 3),
 490         RO_SENSOR_TEMPLATE("power1_cap_hyst", show_val, 4),
 491         RO_SENSOR_TEMPLATE(POWER_ALARM_NAME, show_val, 6),
 492         {},
 493 };
 494
 495 static struct sensor_template ro_cap_attrs[] = {
 496         RO_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, 0),
 497         {},
 498 };
 499
 500 static struct sensor_template rw_cap_attrs[] = {
 501         RW_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, set_cap, 0),
 502         {},
 503 };
 504
 505 static struct sensor_template trip_attrs[] = {
 506         RW_SENSOR_TEMPLATE("power1_average_min", show_val, set_trip, 7),
 507         RW_SENSOR_TEMPLATE("power1_average_max", show_val, set_trip, 8),
 508         {},
 509 };
 510
 511 static struct sensor_template misc_attrs[] = {
 512         RO_SENSOR_TEMPLATE("name", show_name, 0),
 513         RO_SENSOR_TEMPLATE("power1_model_number", show_str, 0),
 514         RO_SENSOR_TEMPLATE("power1_oem_info", show_str, 2),
 515         RO_SENSOR_TEMPLATE("power1_serial_number", show_str, 1),
 516         {},
 517 };
 518
 519 #undef RO_SENSOR_TEMPLATE
 520 #undef RW_SENSOR_TEMPLATE
 521
 522 /* Read power domain data */
 523 static void remove_domain_devices(struct acpi_power_meter_resource *resource)
 524 {
 525         int i;
 526
 527         if (!resource->num_domain_devices)
 528                 return;
 529
 530         for (i = 0; i < resource->num_domain_devices; i++) {
 531                 struct acpi_device *obj = resource->domain_devices[i];
 532                 if (!obj)
 533                         continue;
 534
 535                 sysfs_remove_link(resource->holders_dir,
 536                                   kobject_name(&obj->dev.kobj));
 537                 put_device(&obj->dev);
 538         }
 539
 540         kfree(resource->domain_devices);
 541         kobject_put(resource->holders_dir);
 542         resource->num_domain_devices = 0;
 543 }
 544
 545 static int read_domain_devices(struct acpi_power_meter_resource *resource)
 546 {
 547         int res = 0;
 548         int i;
 549         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 550         union acpi_object *pss;
 551         acpi_status status;
 552
 553         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
 554                                       &buffer);
 555         if (ACPI_FAILURE(status)) {
 556                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMD"));
 557                 return -ENODEV;
 558         }
 559
 560         pss = buffer.pointer;
 561         if (!pss ||
 562             pss->type != ACPI_TYPE_PACKAGE) {
 563                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 564                         "Invalid _PMD data\n");
 565                 res = -EFAULT;
 566                 goto end;
 567         }
 568
 569         if (!pss->package.count)
 570                 goto end;
 571
 572         resource->domain_devices = kcalloc(pss->package.count,
 573                                            sizeof(struct acpi_device *),
 574                                            GFP_KERNEL);
 575         if (!resource->domain_devices) {
 576                 res = -ENOMEM;
 577                 goto end;
 578         }
 579
 580         resource->holders_dir = kobject_create_and_add("measures",
 581                                         &resource->acpi_dev->dev.kobj);
 582         if (!resource->holders_dir) {
 583                 res = -ENOMEM;
 584                 goto exit_free;
 585         }
 586
 587         resource->num_domain_devices = pss->package.count;
 588
 589         for (i = 0; i < pss->package.count; i++) {
 590                 struct acpi_device *obj;
 591                 union acpi_object *element = &(pss->package.elements[i]);
 592
 593                 /* Refuse non-references */
 594                 if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
 595                         continue;
 596
 597                 /* Create a symlink to domain objects */
 598                 resource->domain_devices[i] = NULL;
 599                 if (acpi_bus_get_device(element->reference.handle,
 600                                         &resource->domain_devices[i]))
 601                         continue;
 602
 603                 obj = resource->domain_devices[i];
 604                 get_device(&obj->dev);
 605
 606                 res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
 607                                       kobject_name(&obj->dev.kobj));
 608                 if (res) {
 609                         put_device(&obj->dev);
 610                         resource->domain_devices[i] = NULL;
 611                 }
 612         }
 613
 614         res = 0;
 615         goto end;
 616
 617 exit_free:
 618         kfree(resource->domain_devices);
 619 end:
 620         kfree(buffer.pointer);
 621         return res;
 622 }
 623
 624 /* Registration and deregistration */
 625 static int register_attrs(struct acpi_power_meter_resource *resource,
 626                           struct sensor_template *attrs)
 627 {
 628         struct device *dev = &resource->acpi_dev->dev;
 629         struct sensor_device_attribute *sensors =
 630                 &resource->sensors[resource->num_sensors];
 631         int res = 0;
 632
 633         while (attrs->label) {
 634                 sensors->dev_attr.attr.name = attrs->label;
 635                 sensors->dev_attr.attr.mode = 0444;
 636                 sensors->dev_attr.show = attrs->show;
 637                 sensors->index = attrs->index;
 638
 639                 if (attrs->set) {
 640                         sensors->dev_attr.attr.mode |= 0200;
 641                         sensors->dev_attr.store = attrs->set;
 642                 }
 643
 644                 sysfs_attr_init(&sensors->dev_attr.attr);
 645                 res = device_create_file(dev, &sensors->dev_attr);
 646                 if (res) {
 647                         sensors->dev_attr.attr.name = NULL;
 648                         goto error;
 649                 }
 650                 sensors++;
 651                 resource->num_sensors++;
 652                 attrs++;
 653         }
 654
 655 error:
 656         return res;
 657 }
 658
 659 static void remove_attrs(struct acpi_power_meter_resource *resource)
 660 {
 661         int i;
 662
 663         for (i = 0; i < resource->num_sensors; i++) {
 664                 if (!resource->sensors[i].dev_attr.attr.name)
 665                         continue;
 666                 device_remove_file(&resource->acpi_dev->dev,
 667                                    &resource->sensors[i].dev_attr);
 668         }
 669
 670         remove_domain_devices(resource);
 671
 672         resource->num_sensors = 0;
 673 }
 674
 675 static int setup_attrs(struct acpi_power_meter_resource *resource)
 676 {
 677         int res = 0;
 678
 679         res = read_domain_devices(resource);
 680         if (res)
 681                 return res;
 682
 683         if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
 684                 res = register_attrs(resource, meter_attrs);
 685                 if (res)
 686                         goto error;
 687         }
 688
 689         if (resource->caps.flags & POWER_METER_CAN_CAP) {
 690                 if (!can_cap_in_hardware()) {
 691                         dev_warn(&resource->acpi_dev->dev,
 692                                  "Ignoring unsafe software power cap!\n");
 693                         goto skip_unsafe_cap;
 694                 }
 695
 696                 if (resource->caps.configurable_cap)
 697                         res = register_attrs(resource, rw_cap_attrs);
 698                 else
 699                         res = register_attrs(resource, ro_cap_attrs);
 700
 701                 if (res)
 702                         goto error;
 703
 704                 res = register_attrs(resource, misc_cap_attrs);
 705                 if (res)
 706                         goto error;
 707         }
 708
 709 skip_unsafe_cap:
 710         if (resource->caps.flags & POWER_METER_CAN_TRIP) {
 711                 res = register_attrs(resource, trip_attrs);
 712                 if (res)
 713                         goto error;
 714         }
 715
 716         res = register_attrs(resource, misc_attrs);
 717         if (res)
 718                 goto error;
 719
 720         return res;
 721 error:
 722         remove_attrs(resource);
 723         return res;
 724 }
 725
 726 static void free_capabilities(struct acpi_power_meter_resource *resource)
 727 {
 728         acpi_string *str;
 729         int i;
 730
 731         str = &resource->model_number;
 732         for (i = 0; i < 3; i++, str++)
 733                 kfree(*str);
 734 }
 735
 736 static int read_capabilities(struct acpi_power_meter_resource *resource)
 737 {
 738         int res = 0;
 739         int i;
 740         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 741         struct acpi_buffer state = { 0, NULL };
 742         struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
 743         union acpi_object *pss;
 744         acpi_string *str;
 745         acpi_status status;
 746
 747         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
 748                                       &buffer);
 749         if (ACPI_FAILURE(status)) {
 750                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMC"));
 751                 return -ENODEV;
 752         }
 753
 754         pss = buffer.pointer;
 755         if (!pss ||
 756             pss->type != ACPI_TYPE_PACKAGE ||
 757             pss->package.count != 14) {
 758                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 759                         "Invalid _PMC data\n");
 760                 res = -EFAULT;
 761                 goto end;
 762         }
 763
 764         /* Grab all the integer data at once */
 765         state.length = sizeof(struct acpi_power_meter_capabilities);
 766         state.pointer = &resource->caps;
 767
 768         status = acpi_extract_package(pss, &format, &state);
 769         if (ACPI_FAILURE(status)) {
 770                 ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
 771                 res = -EFAULT;
 772                 goto end;
 773         }
 774
 775         if (resource->caps.units) {
 776                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 777                         "Unknown units %llu.\n",
 778                         resource->caps.units);
 779                 res = -EINVAL;
 780                 goto end;
 781         }
 782
 783         /* Grab the string data */
 784         str = &resource->model_number;
 785
 786         for (i = 11; i < 14; i++) {
 787                 union acpi_object *element = &(pss->package.elements[i]);
 788
 789                 if (element->type != ACPI_TYPE_STRING) {
 790                         res = -EINVAL;
 791                         goto error;
 792                 }
 793
 794                 *str = kcalloc(element->string.length + 1, sizeof(u8),
 795                                GFP_KERNEL);
 796                 if (!*str) {
 797                         res = -ENOMEM;
 798                         goto error;
 799                 }
 800
 801                 strncpy(*str, element->string.pointer, element->string.length);
 802                 str++;
 803         }
 804
 805         dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
 806         goto end;
 807 error:
 808         str = &resource->model_number;
 809         for (i = 0; i < 3; i++, str++)
 810                 kfree(*str);
 811 end:
 812         kfree(buffer.pointer);
 813         return res;
 814 }
 815
 816 /* Handle ACPI event notifications */
 817 static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
 818 {
 819         struct acpi_power_meter_resource *resource;
 820         int res;
 821
 822         if (!device || !acpi_driver_data(device))
 823                 return;
 824
 825         resource = acpi_driver_data(device);
 826
 827         switch (event) {
 828         case METER_NOTIFY_CONFIG:
 829                 mutex_lock(&resource->lock);
 830                 free_capabilities(resource);
 831                 res = read_capabilities(resource);
 832                 mutex_unlock(&resource->lock);
 833                 if (res)
 834                         break;
 835
 836                 remove_attrs(resource);
 837                 setup_attrs(resource);
 838                 break;
 839         case METER_NOTIFY_TRIP:
 840                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
 841                 break;
 842         case METER_NOTIFY_CAP:
 843                 sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
 844                 break;
 845         case METER_NOTIFY_INTERVAL:
 846                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
 847                 break;
 848         case METER_NOTIFY_CAPPING:
 849                 sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
 850                 dev_info(&device->dev, "Capping in progress.\n");
 851                 break;
 852         default:
 853                 WARN(1, "Unexpected event %d\n", event);
 854                 break;
 855         }
 856
 857         acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS,
 858                                         dev_name(&device->dev), event, 0);
 859 }
 860
 861 static int acpi_power_meter_add(struct acpi_device *device)
 862 {
 863         int res;
 864         struct acpi_power_meter_resource *resource;
 865
 866         if (!device)
 867                 return -EINVAL;
 868
 869         resource = kzalloc(sizeof(struct acpi_power_meter_resource),
 870                            GFP_KERNEL);
 871         if (!resource)
 872                 return -ENOMEM;
 873
 874         resource->sensors_valid = 0;
 875         resource->acpi_dev = device;
 876         mutex_init(&resource->lock);
 877         strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
 878         strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
 879         device->driver_data = resource;
 880
 881         free_capabilities(resource);
 882         res = read_capabilities(resource);
 883         if (res)
 884                 goto exit_free;
 885
 886         resource->trip[0] = resource->trip[1] = -1;
 887
 888         res = setup_attrs(resource);
 889         if (res)
 890                 goto exit_free_capability;
 891
 892         resource->hwmon_dev = hwmon_device_register(&device->dev);
 893         if (IS_ERR(resource->hwmon_dev)) {
 894                 res = PTR_ERR(resource->hwmon_dev);
 895                 goto exit_remove;
 896         }
 897
 898         res = 0;
 899         goto exit;
 900
 901 exit_remove:
 902         remove_attrs(resource);
 903 exit_free_capability:
 904         free_capabilities(resource);
 905 exit_free:
 906         kfree(resource);
 907 exit:
 908         return res;
 909 }
 910
 911 static int acpi_power_meter_remove(struct acpi_device *device)
 912 {
 913         struct acpi_power_meter_resource *resource;
 914
 915         if (!device || !acpi_driver_data(device))
 916                 return -EINVAL;
 917
 918         resource = acpi_driver_data(device);
 919         hwmon_device_unregister(resource->hwmon_dev);
 920
 921         remove_attrs(resource);
 922         free_capabilities(resource);
 923
 924         kfree(resource);
 925         return 0;
 926 }
 927
 928 #ifdef CONFIG_PM_SLEEP
 929
 930 static int acpi_power_meter_resume(struct device *dev)
 931 {
 932         struct acpi_power_meter_resource *resource;
 933
 934         if (!dev)
 935                 return -EINVAL;
 936
 937         resource = acpi_driver_data(to_acpi_device(dev));
 938         if (!resource)
 939                 return -EINVAL;
 940
 941         free_capabilities(resource);
 942         read_capabilities(resource);
 943
 944         return 0;
 945 }
 946
 947 #endif /* CONFIG_PM_SLEEP */
 948
 949 static SIMPLE_DEV_PM_OPS(acpi_power_meter_pm, NULL, acpi_power_meter_resume);
 950
 951 static struct acpi_driver acpi_power_meter_driver = {
 952         .name = "power_meter",
 953         .class = ACPI_POWER_METER_CLASS,
 954         .ids = power_meter_ids,
 955         .ops = {
 956                 .add = acpi_power_meter_add,
 957                 .remove = acpi_power_meter_remove,
 958                 .notify = acpi_power_meter_notify,
 959                 },
 960         .drv.pm = &acpi_power_meter_pm,
 961 };
 962
 963 /* Module init/exit routines */
 964 static int __init enable_cap_knobs(const struct dmi_system_id *d)
 965 {
 966         cap_in_hardware = 1;
 967         return 0;
 968 }
 969
 970 static const struct dmi_system_id pm_dmi_table[] __initconst = {
 971         {
 972                 enable_cap_knobs, "IBM Active Energy Manager",
 973                 {
 974                         DMI_MATCH(DMI_SYS_VENDOR, "IBM")
 975                 },
 976         },
 977         {}
 978 };
 979
 980 static int __init acpi_power_meter_init(void)
 981 {
 982         int result;
 983
 984         if (acpi_disabled)
 985                 return -ENODEV;
 986
 987         dmi_check_system(pm_dmi_table);
 988
 989         result = acpi_bus_register_driver(&acpi_power_meter_driver);
 990         if (result < 0)
 991                 return result;
 992
 993         return 0;
 994 }
 995
 996 static void __exit acpi_power_meter_exit(void)
 997 {
 998         acpi_bus_unregister_driver(&acpi_power_meter_driver);
 999 }
1000
1001 MODULE_AUTHOR("Darrick J. Wong <darrick.wong@oracle.com>");
1002 MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
1003 MODULE_LICENSE("GPL");
1004
1005 module_param(force_cap_on, bool, 0644);
1006 MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1007
1008 module_init(acpi_power_meter_init);
1009 module_exit(acpi_power_meter_exit);