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 <[email protected]>
   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 #define ACPI_POWER_METER_DEVICE_NAME    "Power Meter"
  24 #define ACPI_POWER_METER_CLASS          "pwr_meter_resource"
  25
  26 #define NUM_SENSORS                     17
  27
  28 #define POWER_METER_CAN_MEASURE (1 << 0)
  29 #define POWER_METER_CAN_TRIP    (1 << 1)
  30 #define POWER_METER_CAN_CAP     (1 << 2)
  31 #define POWER_METER_CAN_NOTIFY  (1 << 3)
  32 #define POWER_METER_IS_BATTERY  (1 << 8)
  33 #define UNKNOWN_HYSTERESIS      0xFFFFFFFF
  34
  35 #define METER_NOTIFY_CONFIG     0x80
  36 #define METER_NOTIFY_TRIP       0x81
  37 #define METER_NOTIFY_CAP        0x82
  38 #define METER_NOTIFY_CAPPING    0x83
  39 #define METER_NOTIFY_INTERVAL   0x84
  40
  41 #define POWER_AVERAGE_NAME      "power1_average"
  42 #define POWER_CAP_NAME          "power1_cap"
  43 #define POWER_AVG_INTERVAL_NAME "power1_average_interval"
  44 #define POWER_ALARM_NAME        "power1_alarm"
  45
  46 static int cap_in_hardware;
  47 static bool force_cap_on;
  48
  49 static int can_cap_in_hardware(void)
  50 {
  51         return force_cap_on || cap_in_hardware;
  52 }
  53
  54 static const struct acpi_device_id power_meter_ids[] = {
  55         {"ACPI000D", 0},
  56         {"", 0},
  57 };
  58 MODULE_DEVICE_TABLE(acpi, power_meter_ids);
  59
  60 struct acpi_power_meter_capabilities {
  61         u64             flags;
  62         u64             units;
  63         u64             type;
  64         u64             accuracy;
  65         u64             sampling_time;
  66         u64             min_avg_interval;
  67         u64             max_avg_interval;
  68         u64             hysteresis;
  69         u64             configurable_cap;
  70         u64             min_cap;
  71         u64             max_cap;
  72 };
  73
  74 struct acpi_power_meter_resource {
  75         struct acpi_device      *acpi_dev;
  76         acpi_bus_id             name;
  77         struct mutex            lock;
  78         struct device           *hwmon_dev;
  79         struct acpi_power_meter_capabilities    caps;
  80         acpi_string             model_number;
  81         acpi_string             serial_number;
  82         acpi_string             oem_info;
  83         u64             power;
  84         u64             cap;
  85         u64             avg_interval;
  86         int                     sensors_valid;
  87         unsigned long           sensors_last_updated;
  88         struct sensor_device_attribute  sensors[NUM_SENSORS];
  89         int                     num_sensors;
  90         s64                     trip[2];
  91         int                     num_domain_devices;
  92         struct acpi_device      **domain_devices;
  93         struct kobject          *holders_dir;
  94 };
  95
  96 struct sensor_template {
  97         char *label;
  98         ssize_t (*show)(struct device *dev,
  99                         struct device_attribute *devattr,
 100                         char *buf);
 101         ssize_t (*set)(struct device *dev,
 102                        struct device_attribute *devattr,
 103                        const char *buf, size_t count);
 104         int index;
 105 };
 106
 107 /* Averaging interval */
 108 static int update_avg_interval(struct acpi_power_meter_resource *resource)
 109 {
 110         unsigned long long data;
 111         acpi_status status;
 112
 113         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GAI",
 114                                        NULL, &data);
 115         if (ACPI_FAILURE(status)) {
 116                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_GAI",
 117                                              status);
 118                 return -ENODEV;
 119         }
 120
 121         resource->avg_interval = data;
 122         return 0;
 123 }
 124
 125 static ssize_t show_avg_interval(struct device *dev,
 126                                  struct device_attribute *devattr,
 127                                  char *buf)
 128 {
 129         struct acpi_device *acpi_dev = to_acpi_device(dev);
 130         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 131
 132         mutex_lock(&resource->lock);
 133         update_avg_interval(resource);
 134         mutex_unlock(&resource->lock);
 135
 136         return sprintf(buf, "%llu\n", resource->avg_interval);
 137 }
 138
 139 static ssize_t set_avg_interval(struct device *dev,
 140                                 struct device_attribute *devattr,
 141                                 const char *buf, size_t count)
 142 {
 143         struct acpi_device *acpi_dev = to_acpi_device(dev);
 144         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 145         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 146         struct acpi_object_list args = { 1, &arg0 };
 147         int res;
 148         unsigned long temp;
 149         unsigned long long data;
 150         acpi_status status;
 151
 152         res = kstrtoul(buf, 10, &temp);
 153         if (res)
 154                 return res;
 155
 156         if (temp > resource->caps.max_avg_interval ||
 157             temp < resource->caps.min_avg_interval)
 158                 return -EINVAL;
 159         arg0.integer.value = temp;
 160
 161         mutex_lock(&resource->lock);
 162         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PAI",
 163                                        &args, &data);
 164         if (ACPI_SUCCESS(status))
 165                 resource->avg_interval = temp;
 166         mutex_unlock(&resource->lock);
 167
 168         if (ACPI_FAILURE(status)) {
 169                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PAI",
 170                                              status);
 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_evaluation_failure_warn(resource->acpi_dev->handle, "_GHL",
 191                                              status);
 192                 return -ENODEV;
 193         }
 194
 195         resource->cap = data;
 196         return 0;
 197 }
 198
 199 static ssize_t show_cap(struct device *dev,
 200                         struct device_attribute *devattr,
 201                         char *buf)
 202 {
 203         struct acpi_device *acpi_dev = to_acpi_device(dev);
 204         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 205
 206         mutex_lock(&resource->lock);
 207         update_cap(resource);
 208         mutex_unlock(&resource->lock);
 209
 210         return sprintf(buf, "%llu\n", resource->cap * 1000);
 211 }
 212
 213 static ssize_t set_cap(struct device *dev, struct device_attribute *devattr,
 214                        const char *buf, size_t count)
 215 {
 216         struct acpi_device *acpi_dev = to_acpi_device(dev);
 217         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 218         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 219         struct acpi_object_list args = { 1, &arg0 };
 220         int res;
 221         unsigned long temp;
 222         unsigned long long data;
 223         acpi_status status;
 224
 225         res = kstrtoul(buf, 10, &temp);
 226         if (res)
 227                 return res;
 228
 229         temp = DIV_ROUND_CLOSEST(temp, 1000);
 230         if (temp > resource->caps.max_cap || temp < resource->caps.min_cap)
 231                 return -EINVAL;
 232         arg0.integer.value = temp;
 233
 234         mutex_lock(&resource->lock);
 235         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_SHL",
 236                                        &args, &data);
 237         if (ACPI_SUCCESS(status))
 238                 resource->cap = temp;
 239         mutex_unlock(&resource->lock);
 240
 241         if (ACPI_FAILURE(status)) {
 242                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_SHL",
 243                                              status);
 244                 return -EINVAL;
 245         }
 246
 247         /* _SHL returns 0 on success, nonzero otherwise */
 248         if (data)
 249                 return -EINVAL;
 250
 251         return count;
 252 }
 253
 254 /* Power meter trip points */
 255 static int set_acpi_trip(struct acpi_power_meter_resource *resource)
 256 {
 257         union acpi_object arg_objs[] = {
 258                 {ACPI_TYPE_INTEGER},
 259                 {ACPI_TYPE_INTEGER}
 260         };
 261         struct acpi_object_list args = { 2, arg_objs };
 262         unsigned long long data;
 263         acpi_status status;
 264
 265         /* Both trip levels must be set */
 266         if (resource->trip[0] < 0 || resource->trip[1] < 0)
 267                 return 0;
 268
 269         /* This driver stores min, max; ACPI wants max, min. */
 270         arg_objs[0].integer.value = resource->trip[1];
 271         arg_objs[1].integer.value = resource->trip[0];
 272
 273         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PTP",
 274                                        &args, &data);
 275         if (ACPI_FAILURE(status)) {
 276                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PTP",
 277                                              status);
 278                 return -EINVAL;
 279         }
 280
 281         /* _PTP returns 0 on success, nonzero otherwise */
 282         if (data)
 283                 return -EINVAL;
 284
 285         return 0;
 286 }
 287
 288 static ssize_t set_trip(struct device *dev, struct device_attribute *devattr,
 289                         const char *buf, size_t count)
 290 {
 291         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 292         struct acpi_device *acpi_dev = to_acpi_device(dev);
 293         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 294         int res;
 295         unsigned long temp;
 296
 297         res = kstrtoul(buf, 10, &temp);
 298         if (res)
 299                 return res;
 300
 301         temp = DIV_ROUND_CLOSEST(temp, 1000);
 302
 303         mutex_lock(&resource->lock);
 304         resource->trip[attr->index - 7] = temp;
 305         res = set_acpi_trip(resource);
 306         mutex_unlock(&resource->lock);
 307
 308         if (res)
 309                 return res;
 310
 311         return count;
 312 }
 313
 314 /* Power meter */
 315 static int update_meter(struct acpi_power_meter_resource *resource)
 316 {
 317         unsigned long long data;
 318         acpi_status status;
 319         unsigned long local_jiffies = jiffies;
 320
 321         if (time_before(local_jiffies, resource->sensors_last_updated +
 322                         msecs_to_jiffies(resource->caps.sampling_time)) &&
 323                         resource->sensors_valid)
 324                 return 0;
 325
 326         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PMM",
 327                                        NULL, &data);
 328         if (ACPI_FAILURE(status)) {
 329                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PMM",
 330                                              status);
 331                 return -ENODEV;
 332         }
 333
 334         resource->power = data;
 335         resource->sensors_valid = 1;
 336         resource->sensors_last_updated = jiffies;
 337         return 0;
 338 }
 339
 340 static ssize_t show_power(struct device *dev,
 341                           struct device_attribute *devattr,
 342                           char *buf)
 343 {
 344         struct acpi_device *acpi_dev = to_acpi_device(dev);
 345         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 346
 347         mutex_lock(&resource->lock);
 348         update_meter(resource);
 349         mutex_unlock(&resource->lock);
 350
 351         return sprintf(buf, "%llu\n", resource->power * 1000);
 352 }
 353
 354 /* Miscellaneous */
 355 static ssize_t show_str(struct device *dev,
 356                         struct device_attribute *devattr,
 357                         char *buf)
 358 {
 359         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 360         struct acpi_device *acpi_dev = to_acpi_device(dev);
 361         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 362         acpi_string val;
 363         int ret;
 364
 365         mutex_lock(&resource->lock);
 366         switch (attr->index) {
 367         case 0:
 368                 val = resource->model_number;
 369                 break;
 370         case 1:
 371                 val = resource->serial_number;
 372                 break;
 373         case 2:
 374                 val = resource->oem_info;
 375                 break;
 376         default:
 377                 WARN(1, "Implementation error: unexpected attribute index %d\n",
 378                      attr->index);
 379                 val = "";
 380                 break;
 381         }
 382         ret = sprintf(buf, "%s\n", val);
 383         mutex_unlock(&resource->lock);
 384         return ret;
 385 }
 386
 387 static ssize_t show_val(struct device *dev,
 388                         struct device_attribute *devattr,
 389                         char *buf)
 390 {
 391         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 392         struct acpi_device *acpi_dev = to_acpi_device(dev);
 393         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 394         u64 val = 0;
 395
 396         switch (attr->index) {
 397         case 0:
 398                 val = resource->caps.min_avg_interval;
 399                 break;
 400         case 1:
 401                 val = resource->caps.max_avg_interval;
 402                 break;
 403         case 2:
 404                 val = resource->caps.min_cap * 1000;
 405                 break;
 406         case 3:
 407                 val = resource->caps.max_cap * 1000;
 408                 break;
 409         case 4:
 410                 if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
 411                         return sprintf(buf, "unknown\n");
 412
 413                 val = resource->caps.hysteresis * 1000;
 414                 break;
 415         case 5:
 416                 if (resource->caps.flags & POWER_METER_IS_BATTERY)
 417                         val = 1;
 418                 else
 419                         val = 0;
 420                 break;
 421         case 6:
 422                 if (resource->power > resource->cap)
 423                         val = 1;
 424                 else
 425                         val = 0;
 426                 break;
 427         case 7:
 428         case 8:
 429                 if (resource->trip[attr->index - 7] < 0)
 430                         return sprintf(buf, "unknown\n");
 431
 432                 val = resource->trip[attr->index - 7] * 1000;
 433                 break;
 434         default:
 435                 WARN(1, "Implementation error: unexpected attribute index %d\n",
 436                      attr->index);
 437                 break;
 438         }
 439
 440         return sprintf(buf, "%llu\n", val);
 441 }
 442
 443 static ssize_t show_accuracy(struct device *dev,
 444                              struct device_attribute *devattr,
 445                              char *buf)
 446 {
 447         struct acpi_device *acpi_dev = to_acpi_device(dev);
 448         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 449         unsigned int acc = resource->caps.accuracy;
 450
 451         return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
 452 }
 453
 454 static ssize_t show_name(struct device *dev,
 455                          struct device_attribute *devattr,
 456                          char *buf)
 457 {
 458         return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
 459 }
 460
 461 #define RO_SENSOR_TEMPLATE(_label, _show, _index)       \
 462         {                                               \
 463                 .label = _label,                        \
 464                 .show  = _show,                         \
 465                 .index = _index,                        \
 466         }
 467
 468 #define RW_SENSOR_TEMPLATE(_label, _show, _set, _index) \
 469         {                                               \
 470                 .label = _label,                        \
 471                 .show  = _show,                         \
 472                 .set   = _set,                          \
 473                 .index = _index,                        \
 474         }
 475
 476 /* Sensor descriptions.  If you add a sensor, update NUM_SENSORS above! */
 477 static struct sensor_template meter_attrs[] = {
 478         RO_SENSOR_TEMPLATE(POWER_AVERAGE_NAME, show_power, 0),
 479         RO_SENSOR_TEMPLATE("power1_accuracy", show_accuracy, 0),
 480         RO_SENSOR_TEMPLATE("power1_average_interval_min", show_val, 0),
 481         RO_SENSOR_TEMPLATE("power1_average_interval_max", show_val, 1),
 482         RO_SENSOR_TEMPLATE("power1_is_battery", show_val, 5),
 483         RW_SENSOR_TEMPLATE(POWER_AVG_INTERVAL_NAME, show_avg_interval,
 484                 set_avg_interval, 0),
 485         {},
 486 };
 487
 488 static struct sensor_template misc_cap_attrs[] = {
 489         RO_SENSOR_TEMPLATE("power1_cap_min", show_val, 2),
 490         RO_SENSOR_TEMPLATE("power1_cap_max", show_val, 3),
 491         RO_SENSOR_TEMPLATE("power1_cap_hyst", show_val, 4),
 492         RO_SENSOR_TEMPLATE(POWER_ALARM_NAME, show_val, 6),
 493         {},
 494 };
 495
 496 static struct sensor_template ro_cap_attrs[] = {
 497         RO_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, 0),
 498         {},
 499 };
 500
 501 static struct sensor_template rw_cap_attrs[] = {
 502         RW_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, set_cap, 0),
 503         {},
 504 };
 505
 506 static struct sensor_template trip_attrs[] = {
 507         RW_SENSOR_TEMPLATE("power1_average_min", show_val, set_trip, 7),
 508         RW_SENSOR_TEMPLATE("power1_average_max", show_val, set_trip, 8),
 509         {},
 510 };
 511
 512 static struct sensor_template misc_attrs[] = {
 513         RO_SENSOR_TEMPLATE("name", show_name, 0),
 514         RO_SENSOR_TEMPLATE("power1_model_number", show_str, 0),
 515         RO_SENSOR_TEMPLATE("power1_oem_info", show_str, 2),
 516         RO_SENSOR_TEMPLATE("power1_serial_number", show_str, 1),
 517         {},
 518 };
 519
 520 #undef RO_SENSOR_TEMPLATE
 521 #undef RW_SENSOR_TEMPLATE
 522
 523 /* Read power domain data */
 524 static void remove_domain_devices(struct acpi_power_meter_resource *resource)
 525 {
 526         int i;
 527
 528         if (!resource->num_domain_devices)
 529                 return;
 530
 531         for (i = 0; i < resource->num_domain_devices; i++) {
 532                 struct acpi_device *obj = resource->domain_devices[i];
 533                 if (!obj)
 534                         continue;
 535
 536                 sysfs_remove_link(resource->holders_dir,
 537                                   kobject_name(&obj->dev.kobj));
 538                 put_device(&obj->dev);
 539         }
 540
 541         kfree(resource->domain_devices);
 542         kobject_put(resource->holders_dir);
 543         resource->num_domain_devices = 0;
 544 }
 545
 546 static int read_domain_devices(struct acpi_power_meter_resource *resource)
 547 {
 548         int res = 0;
 549         int i;
 550         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 551         union acpi_object *pss;
 552         acpi_status status;
 553
 554         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
 555                                       &buffer);
 556         if (ACPI_FAILURE(status)) {
 557                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PMD",
 558                                              status);
 559                 return -ENODEV;
 560         }
 561
 562         pss = buffer.pointer;
 563         if (!pss ||
 564             pss->type != ACPI_TYPE_PACKAGE) {
 565                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 566                         "Invalid _PMD data\n");
 567                 res = -EFAULT;
 568                 goto end;
 569         }
 570
 571         if (!pss->package.count)
 572                 goto end;
 573
 574         resource->domain_devices = kcalloc(pss->package.count,
 575                                            sizeof(struct acpi_device *),
 576                                            GFP_KERNEL);
 577         if (!resource->domain_devices) {
 578                 res = -ENOMEM;
 579                 goto end;
 580         }
 581
 582         resource->holders_dir = kobject_create_and_add("measures",
 583                                         &resource->acpi_dev->dev.kobj);
 584         if (!resource->holders_dir) {
 585                 res = -ENOMEM;
 586                 goto exit_free;
 587         }
 588
 589         resource->num_domain_devices = pss->package.count;
 590
 591         for (i = 0; i < pss->package.count; i++) {
 592                 struct acpi_device *obj;
 593                 union acpi_object *element = &(pss->package.elements[i]);
 594
 595                 /* Refuse non-references */
 596                 if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
 597                         continue;
 598
 599                 /* Create a symlink to domain objects */
 600                 resource->domain_devices[i] = NULL;
 601                 if (acpi_bus_get_device(element->reference.handle,
 602                                         &resource->domain_devices[i]))
 603                         continue;
 604
 605                 obj = resource->domain_devices[i];
 606                 get_device(&obj->dev);
 607
 608                 res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
 609                                       kobject_name(&obj->dev.kobj));
 610                 if (res) {
 611                         put_device(&obj->dev);
 612                         resource->domain_devices[i] = NULL;
 613                 }
 614         }
 615
 616         res = 0;
 617         goto end;
 618
 619 exit_free:
 620         kfree(resource->domain_devices);
 621 end:
 622         kfree(buffer.pointer);
 623         return res;
 624 }
 625
 626 /* Registration and deregistration */
 627 static int register_attrs(struct acpi_power_meter_resource *resource,
 628                           struct sensor_template *attrs)
 629 {
 630         struct device *dev = &resource->acpi_dev->dev;
 631         struct sensor_device_attribute *sensors =
 632                 &resource->sensors[resource->num_sensors];
 633         int res = 0;
 634
 635         while (attrs->label) {
 636                 sensors->dev_attr.attr.name = attrs->label;
 637                 sensors->dev_attr.attr.mode = 0444;
 638                 sensors->dev_attr.show = attrs->show;
 639                 sensors->index = attrs->index;
 640
 641                 if (attrs->set) {
 642                         sensors->dev_attr.attr.mode |= 0200;
 643                         sensors->dev_attr.store = attrs->set;
 644                 }
 645
 646                 sysfs_attr_init(&sensors->dev_attr.attr);
 647                 res = device_create_file(dev, &sensors->dev_attr);
 648                 if (res) {
 649                         sensors->dev_attr.attr.name = NULL;
 650                         goto error;
 651                 }
 652                 sensors++;
 653                 resource->num_sensors++;
 654                 attrs++;
 655         }
 656
 657 error:
 658         return res;
 659 }
 660
 661 static void remove_attrs(struct acpi_power_meter_resource *resource)
 662 {
 663         int i;
 664
 665         for (i = 0; i < resource->num_sensors; i++) {
 666                 if (!resource->sensors[i].dev_attr.attr.name)
 667                         continue;
 668                 device_remove_file(&resource->acpi_dev->dev,
 669                                    &resource->sensors[i].dev_attr);
 670         }
 671
 672         remove_domain_devices(resource);
 673
 674         resource->num_sensors = 0;
 675 }
 676
 677 static int setup_attrs(struct acpi_power_meter_resource *resource)
 678 {
 679         int res = 0;
 680
 681         res = read_domain_devices(resource);
 682         if (res)
 683                 return res;
 684
 685         if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
 686                 res = register_attrs(resource, meter_attrs);
 687                 if (res)
 688                         goto error;
 689         }
 690
 691         if (resource->caps.flags & POWER_METER_CAN_CAP) {
 692                 if (!can_cap_in_hardware()) {
 693                         dev_warn(&resource->acpi_dev->dev,
 694                                  "Ignoring unsafe software power cap!\n");
 695                         goto skip_unsafe_cap;
 696                 }
 697
 698                 if (resource->caps.configurable_cap)
 699                         res = register_attrs(resource, rw_cap_attrs);
 700                 else
 701                         res = register_attrs(resource, ro_cap_attrs);
 702
 703                 if (res)
 704                         goto error;
 705
 706                 res = register_attrs(resource, misc_cap_attrs);
 707                 if (res)
 708                         goto error;
 709         }
 710
 711 skip_unsafe_cap:
 712         if (resource->caps.flags & POWER_METER_CAN_TRIP) {
 713                 res = register_attrs(resource, trip_attrs);
 714                 if (res)
 715                         goto error;
 716         }
 717
 718         res = register_attrs(resource, misc_attrs);
 719         if (res)
 720                 goto error;
 721
 722         return res;
 723 error:
 724         remove_attrs(resource);
 725         return res;
 726 }
 727
 728 static void free_capabilities(struct acpi_power_meter_resource *resource)
 729 {
 730         acpi_string *str;
 731         int i;
 732
 733         str = &resource->model_number;
 734         for (i = 0; i < 3; i++, str++) {
 735                 kfree(*str);
 736                 *str = NULL;
 737         }
 738 }
 739
 740 static int read_capabilities(struct acpi_power_meter_resource *resource)
 741 {
 742         int res = 0;
 743         int i;
 744         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 745         struct acpi_buffer state = { 0, NULL };
 746         struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
 747         union acpi_object *pss;
 748         acpi_string *str;
 749         acpi_status status;
 750
 751         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
 752                                       &buffer);
 753         if (ACPI_FAILURE(status)) {
 754                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PMC",
 755                                              status);
 756                 return -ENODEV;
 757         }
 758
 759         pss = buffer.pointer;
 760         if (!pss ||
 761             pss->type != ACPI_TYPE_PACKAGE ||
 762             pss->package.count != 14) {
 763                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 764                         "Invalid _PMC data\n");
 765                 res = -EFAULT;
 766                 goto end;
 767         }
 768
 769         /* Grab all the integer data at once */
 770         state.length = sizeof(struct acpi_power_meter_capabilities);
 771         state.pointer = &resource->caps;
 772
 773         status = acpi_extract_package(pss, &format, &state);
 774         if (ACPI_FAILURE(status)) {
 775                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 776                         "_PMC package parsing failed: %s\n",
 777                         acpi_format_exception(status));
 778                 res = -EFAULT;
 779                 goto end;
 780         }
 781
 782         if (resource->caps.units) {
 783                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 784                         "Unknown units %llu.\n",
 785                         resource->caps.units);
 786                 res = -EINVAL;
 787                 goto end;
 788         }
 789
 790         /* Grab the string data */
 791         str = &resource->model_number;
 792
 793         for (i = 11; i < 14; i++) {
 794                 union acpi_object *element = &(pss->package.elements[i]);
 795
 796                 if (element->type != ACPI_TYPE_STRING) {
 797                         res = -EINVAL;
 798                         goto error;
 799                 }
 800
 801                 *str = kcalloc(element->string.length + 1, sizeof(u8),
 802                                GFP_KERNEL);
 803                 if (!*str) {
 804                         res = -ENOMEM;
 805                         goto error;
 806                 }
 807
 808                 strncpy(*str, element->string.pointer, element->string.length);
 809                 str++;
 810         }
 811
 812         dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
 813         goto end;
 814 error:
 815         free_capabilities(resource);
 816 end:
 817         kfree(buffer.pointer);
 818         return res;
 819 }
 820
 821 /* Handle ACPI event notifications */
 822 static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
 823 {
 824         struct acpi_power_meter_resource *resource;
 825         int res;
 826
 827         if (!device || !acpi_driver_data(device))
 828                 return;
 829
 830         resource = acpi_driver_data(device);
 831
 832         switch (event) {
 833         case METER_NOTIFY_CONFIG:
 834                 mutex_lock(&resource->lock);
 835                 free_capabilities(resource);
 836                 res = read_capabilities(resource);
 837                 mutex_unlock(&resource->lock);
 838                 if (res)
 839                         break;
 840
 841                 remove_attrs(resource);
 842                 setup_attrs(resource);
 843                 break;
 844         case METER_NOTIFY_TRIP:
 845                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
 846                 break;
 847         case METER_NOTIFY_CAP:
 848                 sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
 849                 break;
 850         case METER_NOTIFY_INTERVAL:
 851                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
 852                 break;
 853         case METER_NOTIFY_CAPPING:
 854                 sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
 855                 dev_info(&device->dev, "Capping in progress.\n");
 856                 break;
 857         default:
 858                 WARN(1, "Unexpected event %d\n", event);
 859                 break;
 860         }
 861
 862         acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS,
 863                                         dev_name(&device->dev), event, 0);
 864 }
 865
 866 static int acpi_power_meter_add(struct acpi_device *device)
 867 {
 868         int res;
 869         struct acpi_power_meter_resource *resource;
 870
 871         if (!device)
 872                 return -EINVAL;
 873
 874         resource = kzalloc(sizeof(struct acpi_power_meter_resource),
 875                            GFP_KERNEL);
 876         if (!resource)
 877                 return -ENOMEM;
 878
 879         resource->sensors_valid = 0;
 880         resource->acpi_dev = device;
 881         mutex_init(&resource->lock);
 882         strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
 883         strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
 884         device->driver_data = resource;
 885
 886         res = read_capabilities(resource);
 887         if (res)
 888                 goto exit_free;
 889
 890         resource->trip[0] = resource->trip[1] = -1;
 891
 892         res = setup_attrs(resource);
 893         if (res)
 894                 goto exit_free_capability;
 895
 896         resource->hwmon_dev = hwmon_device_register(&device->dev);
 897         if (IS_ERR(resource->hwmon_dev)) {
 898                 res = PTR_ERR(resource->hwmon_dev);
 899                 goto exit_remove;
 900         }
 901
 902         res = 0;
 903         goto exit;
 904
 905 exit_remove:
 906         remove_attrs(resource);
 907 exit_free_capability:
 908         free_capabilities(resource);
 909 exit_free:
 910         kfree(resource);
 911 exit:
 912         return res;
 913 }
 914
 915 static int acpi_power_meter_remove(struct acpi_device *device)
 916 {
 917         struct acpi_power_meter_resource *resource;
 918
 919         if (!device || !acpi_driver_data(device))
 920                 return -EINVAL;
 921
 922         resource = acpi_driver_data(device);
 923         hwmon_device_unregister(resource->hwmon_dev);
 924
 925         remove_attrs(resource);
 926         free_capabilities(resource);
 927
 928         kfree(resource);
 929         return 0;
 930 }
 931
 932 #ifdef CONFIG_PM_SLEEP
 933
 934 static int acpi_power_meter_resume(struct device *dev)
 935 {
 936         struct acpi_power_meter_resource *resource;
 937
 938         if (!dev)
 939                 return -EINVAL;
 940
 941         resource = acpi_driver_data(to_acpi_device(dev));
 942         if (!resource)
 943                 return -EINVAL;
 944
 945         free_capabilities(resource);
 946         read_capabilities(resource);
 947
 948         return 0;
 949 }
 950
 951 #endif /* CONFIG_PM_SLEEP */
 952
 953 static SIMPLE_DEV_PM_OPS(acpi_power_meter_pm, NULL, acpi_power_meter_resume);
 954
 955 static struct acpi_driver acpi_power_meter_driver = {
 956         .name = "power_meter",
 957         .class = ACPI_POWER_METER_CLASS,
 958         .ids = power_meter_ids,
 959         .ops = {
 960                 .add = acpi_power_meter_add,
 961                 .remove = acpi_power_meter_remove,
 962                 .notify = acpi_power_meter_notify,
 963                 },
 964         .drv.pm = &acpi_power_meter_pm,
 965 };
 966
 967 /* Module init/exit routines */
 968 static int __init enable_cap_knobs(const struct dmi_system_id *d)
 969 {
 970         cap_in_hardware = 1;
 971         return 0;
 972 }
 973
 974 static const struct dmi_system_id pm_dmi_table[] __initconst = {
 975         {
 976                 enable_cap_knobs, "IBM Active Energy Manager",
 977                 {
 978                         DMI_MATCH(DMI_SYS_VENDOR, "IBM")
 979                 },
 980         },
 981         {}
 982 };
 983
 984 static int __init acpi_power_meter_init(void)
 985 {
 986         int result;
 987
 988         if (acpi_disabled)
 989                 return -ENODEV;
 990
 991         dmi_check_system(pm_dmi_table);
 992
 993         result = acpi_bus_register_driver(&acpi_power_meter_driver);
 994         if (result < 0)
 995                 return result;
 996
 997         return 0;
 998 }
 999
1000 static void __exit acpi_power_meter_exit(void)
1001 {
1002         acpi_bus_unregister_driver(&acpi_power_meter_driver);
1003 }
1004
1005 MODULE_AUTHOR("Darrick J. Wong <[email protected]>");
1006 MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
1007 MODULE_LICENSE("GPL");
1008
1009 module_param(force_cap_on, bool, 0644);
1010 MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1011
1012 module_init(acpi_power_meter_init);
1013 module_exit(acpi_power_meter_exit);